Evaluation of Ocean
Disposal of Manganese
Nodule Processing Waste
and Environmental
Considerations
July 1982
U.S. DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
Office of Ocean Minerals and Energy
U.S. ENVIRONMENTAL PROTECTION AGENCY
Criteria and Standards Division
Ocean Programs Branch
-------
Evaluation of Ocean
Disposal of Manganese
Nodule Processing Waste
and Environmental
Considerations
Prepared By:
Tetra Tech, Inc.
Beilevue, Washington
July 1982
A Contract Report Prepared For:
U.S. DEPARTMENT OF COMMERCE
Malcolm Baldrige, Secretary
National Oceanic and Atmospheric Administration
John V. Byrne, Administrator
Office of Ocean Minerals and Energy
James P. Lawless, Acting Director
U.S. ENVIRONMENTAL PROTECTION AGENCY
Criteria and Standards Division
Ocean Programs Branch
-------
Final Report
Evaluation of Ocean Disposal of Manganese Nodule
Processing Waste and Environmental Considerations
July, 1982
Prepared by:
Gary Bigham
Thomas Ginn
A. Mills Sol date
Lawrence McCrone
Tetra Tech, Inc.
1900 116th Avenue, N.E.
Bellevue, Washington 98004
Prepared for:
Office of Ocean Minerals and Energy
National Oceanic and Atmospheric Administration
Washington, D.C.
and
Criteria and Standards Division
Ocean Programs Branch
U.S. Environmental Protection Agency
Washington, D.C.
-------
NOTICE
The findings compiled in this report, and interpretations expressed therein,
do not necessarily represent the viewpoints of the National Oceanic and
Atmospheric Administration, the United States Department of Commerce, or the
United States Environmental Protection Agency. The United States—while
making this information available because of its obvious value and in the
public interest—assumes no responsibility for any of the views expressed
therein. The National Oceanic and Atmospheric Administration and the
Environmental Protection Agency do not approve, recommend, or endorse any
proprietary product or proprietary material mentioned in this publication.
No reference shall be made to the National Oceanic and Atmospheric
Administration or the Environmental Protection Agency that would
imply—directly or indi rectly--that the National Oceanic and Atmospheric
Administration or the Environmental Protection Agency approves or disproves
of the use of any proprietary product or proprietary material mentioned
herein.
-------
CONTENTS
Page
FIGURES ix
TABLES xvi
EXECUTIVE SUMMARY E-l
Processing Waste E-l
Ocean Disposal E-3
Current Ocean Disposal Activity E-4
Regulatory Requirements E-4
Characteristics of Representative Disposal Areas E-5
Environmental Considerations E-6
1. INTRODUCTION 1
2. LEGAL AND REGULATORY REQUIREMENTS APPLICABLE TO OCEAN DISPOSAL
OF MANGANESE NODULE PROCESSING REJECTS 3
Ocean Dumping 5
London Dumping Convention 5
Marine Protection, Research, and Sanctuaries Act 6
Ocean Discharge 19
Clean Water Act 19
Other Regulatory Programs Involved 29
Deep Seabed Hard Mineral Resources Act 29
National Environmental Policy Act 31
-------
Coastal Zone Management Act 31
Fish and Wildlife Coordination Act 36
Endangered Species Act 36
Marine Mammal Protection Act 37
National Historic Preservation Act 37
Conclusions 37
3. OCEAN DISPOSAL TECHNOLOGIES 39
Disposal Technology 39
Ocean Dumping 39
Fate of Ocean Dumped Material 43
Barge Dumping 43
Surface and Subsurface Disposal 46
Marine Outfalls 53
Additional Concepts 55
Block Formation 55
Capping 55
Disposal at Existing Designated Sites 56
4. CURRENT OCEAN DISPOSAL ACTIVITY 57
Waste Quantities and Disposal Sites 58
Ocean Dumping 58
Ocean Discharge 62
5. CHARACTERIZATION OF NODULE PROCESSING REJECTS AND WASTES
AND COMPARISON TO OTHER WASTES 66
Summary of Extraction Processes 67
Reduction-Ammonia Leach 68
-------
Cuprion-Ammoniacal Leach 70
High Temperature Sulfuric Acid Leach 72
Reduction-Hydrochloric Acid Leach 74
Smelting-Sulfuric Acid Leach 76
Waste Streams 78
Rejects 78
Additional Waste Streams 82
Update of NOAA's 1977 Evaluation 87
Waste Re-Utilization Considerations 88
Summary of Process Technologies 92
CUPRION- and Reduction-Ammonia Leach Processes 92
High Temperature Reduction-Sulfuric Acid Leach 95
Smelting-Sulfuric Acid Leach 95
Comparison to Other Wastes 96
6. REPRESENTATIVE DISPOSAL AREA CHARACTERISTICS 103
Western Gulf of Mexico 104
Physical Characteristics 104
Characteristics of Representative Areas 104
Fate of Material 108
Marine Biological Characteristics 108
Southern California Bight 111
Physical Characteristics 111
Representative Areas 113
Fate of Material 115
Marine Biological Characteristics 117
iv
-------
Pacific Northwest Region 119
Physical Characteristics 119
Representative Disposal Site Characteristics 119
Fate of Materials 122
Marine Biological Characteristics 122
Hawaii 126
Physical Characteristics 126
Representative Area 129
Fate of Material 130
Marine Biological Characteristics 130
Summary - Marine Biological Characteristics 133
7. ENVIRONMENTAL CONSIDERATIONS RELATED TO MANGANESE NODULE
PROCESSING WASTE DISPOSAL 135
Marine Disposal of Other Wastes 135
Mine Tailings 136
Drilling Muds 143
Dredged Material Disposal 144
Sewage Solids 146
Summary 146
Generic Effects of Manganese Nodule Processing Rejects Disposal
on Marine Communities 148
Possible Biological Impacts of the Deep Ocean Disposal of
Manganese Nodule Processing Rejects 148
Possible Biological Impacts of the Disposal of Manganese
Nodule Processing Rejects on the Continental Shelves 156
Possible Biological Impacts of the Disposal of Manganese
Nodule Processing Rejects in Nearshore Areas 163
Significant Environmental Considerations 166
-------
Environmental Considerations for Representative Disposal
Areas 172
Western Gulf of Mexico 172
Hawaii 173
Pacific Northwest 173
Southern California 175
Evaluation of Disposal Options 176
8. RESEARCH AND STUDY REQUIREMENTS FOR ASSESSING REJECT
OCEAN DISPOSAL 181
Basis for Recommendations 181
Regulatory Requirements 181
Major Environmental Concerns 182
Biological Assessment 184
Assessment of the Potential for Toxicity 184
Assessment of the Bioaccumulation of any
Potentially-Toxic Components 188
Establishment of Baseline Environmental Conditions 189
Chemical Assessment 190
Physical Assessment 191
GLOSSARY 194
REFERENCES 199
APPENDIX A - SUMMARY OF LONDON DUMPING CONVENTION 231
APPENDIX B - TECHNICAL BASIS FOR METHODS TO PREDICT THE FATE
OF OCEAN DISPOSED PROCESSING REJECTS 237
Introduction 237
Ocean Dumping 237
-------
Pump Down 253
APPENDIX C - CHARACTERISTICS OF WASTES SIMILAR TO MANGANESE
NODULE PROCESSING REJECTS 262
Mine Waste Discharges 262
Copper Mines 262
Iron Mines 276
Lead-Zinc Mines 276
Nickel Processing 285
Bauxite Mines 285
Potash Mines 289
Dredged Material 289
Drilling Muds and Cuttings 292
APPENDIX D - DETAILED DESCRIPTION OF THE OCEANOGRAPHIC
CHARACTERISTICS FOR REPRESENTATIVE DISPOSAL AREAS 296
Western Gulf of Mexico 296
Physical Characteristics 296
Characteristics of Representative Areas 303
Biological Characteristics 313
Southern California Bight 323
Physical Characteristics 323
Representative Areas 330
Biological Characteristics 342
Pacific Northwest Region 356
Physical Characteristics 356
Representative Disposal Site Characteristics 363
Biological Characteristics 380
-------
Hawaii 402
Physical Characteristics 402
Representative Area 409
Biological Characteristics 409
-------
FIGURES
Number Page
1 Flow diagram of current permitting procedures
for ocean dumping 18
2 NPDES permit agency decision process for 403(c)
evaluations 27
3 A split-hull bottom dump barge in open and closed
configuration 41
4 The dumping sequence of a split-hull barge 42
5 Schematic representation of ocean dumping 44
6 Idealized discharge from moving vessel 45
7 Horizontal area covered by instantaneous dump
cloud 4 hours after dumping as a function of
trapping level 47
8 Dilution achieved by instantaneous dump cloud
4 hours after dumping as a function of trapping level 48
9 Thickness of sediment layer if the solids suspended
in the dump cloud were to fall uniformly in the
horizontal cloud area after 4 hours time
(initial cloud density = 1.4 g/cm3) 49
10 Thickness of sediment layer if the solids suspended
in the dump cloud were to fall uniformly in the
horizontal cloud area after 4 hours time
(initial cloud density = 2.0 g/cm3) 50
11 Submerged diffuser 52
12 A) Negatively buoyant discharge on a sloping bottom
B) Positively buoyant discharge on a horizontal bottom 54
13 Reduction/ammoniacal leach process 69
14 Cuprion/ammoniacal leach process 71
15 High temperature sulfuric acid leach process 73
rx
-------
16 Reduction/hydrochloric acid leach process 75
17 Smelting process 77
18 Bathymetry of Gulf of Mexico 105
19 Physiographic subdivisions of the Gulf of Mexico
and selected stations of Hidalgo 62-H-3 cruise of
March 22-27, 1962 106
20 Continental borderlands off southern California showing
basins, canyons, and escarpments
21 Relative positions of major submarine banks
and canyons off Northwest coast 120
22 Stations used for the estimation of instantaneous
dump characteristics in the Pacific Northwest 123
23 Bathymetry of the Puna Canyon 127
24 Proposed and alternative dredged material disposal sites 128
25 Maximum fall distance for various hemispherical cloud
diameters and normalized density gradients e when the
initial cloud density = 1.44 g/cm3 239
26 Maximum fall distance for various hemispherical cloud
diameters and.normalized density gradients e when the
initial cloud density = 2.0 g/cm3 241
27 Initial dilutions for instantaneous dumps as a function of
depth (based on convective descent equations of Brandsma
and Koh 1976) 242
28 Horizontal area covered by instantaneous dump cloud
4 hours after dumping as a function of trapping level 247
29 Dilution achieved by instantaneous dump cloud 4 hours
after dumping as a function of trapping level 248
30 Thickness of sediment layer if the solids suspended in the
dump cloud were to fall uniformly in the horizontal cloud
area after 4 hours time (initial cloud density = 2.0 g/cm3) 249
31 Thickness of sediment layer if the solids suspended in
the dump cloud were to fall uniformly in the horizontal
cloud area after 4 hours time (initial cloud density =
1.4 g/cmj) 250
32 Width to initial width (L/Lo) and center!ine concentration
to initial center!ine concentration (c/co) ratios 255
-------
33 Area influenced by a continuous discharge after
4 hours time 256
34 Area as a function of time for average current speed =
0.001 m/sec for various initial widths between 10 and
1,000 m 257
35 Area as a function of time for average current speed =
0.01 m/sec for various initial widths between 10 and
1,000 m 258
36 Areas impacted by sediment first encountering the seafloor
at a given time (horizontal current speed is 0.001 m/sec) 260
37 Areas impacted by sediment first encountering the seafloor
at a given time (horizontal current speed is 0.01 m/sec) 261
38 Location of the Island Copper Mine and submarine outfall
into Rupert Inlet, British Columbia 268
39 Typical size distribution of tailings solids discharged
into Rupert Inlet 269
40 Location of the Britannia Mine on Howe Sound, British
Columbia 273
41 Location of the Jordan River Mine, British Columbia 274
42 Location of the El Salvador Copper Mine, Chile 277
43 Location of the Repparfjord Copper Mine in northern
Norway 278
44 Locations of the Ma On Shan tailing disposal area,
Railway Beach, and Long Harbour, Hong Kong 279
45 Map of the Ma On Shan tailing disposal site, Tolo
Harbour, Hong Kong 280
46 Location of the Kennedy Lake Iron Mines on Toquart
Bay, British Columbia 283
47 Location of the Greenex Lead-Zinc Mine, Greenland 284
48 Location of Yabulu Nickel Refinery Outfall 286
49 Locations of the bauxite refinery and red mud settling
ponds at Gove, Australia 288
50 Locations of the Cleveland Potash Mine and submarine
outfall in Boulby, Yorkshire, England 290
XI
-------
51 Diagram of submarine tunnel used for the discharge
of potash mine tailings by Cleveland Potash, Ltd.,
Yorkshire, England 291
52 Bathymetry of Gulf of Mexico 297
53 Physiographic subdivisions of the Gulf of Mexico
and selected stations of Hidalgo 62-H-3 cruise of
March 22-27, 1962 298
54 Profiles from the shoreline to the upper continental
slope 30°
55 Dynamic topography of sea surface relative to the
1,000-db surface, Hidalgo 62-H-3, x's indicate some
extrapolation. Contour interval, 0.05 dynamic meters 302
56 Characteristics of a Western Gulf of Mexico mid-
shelf disposal site 305
57 Temperature and salinity profiles characteristic of
the western Gulf of Mexico upper slope, Hidalgo Cruise
62-H-3, March, 1972 307
58 Density and dissolved oxygen profiles characteristic
of the western Gul.f of Mexico upper slope, Hidalgo
Cruise 62-H-3, March, 1972 308
59 Geostrophic flow profile for an upper-slope area between
Stations 122 and 123, Hidalgo Cruise 62-H-3, March, 1972 309
60 Salinity and temperature profiles for a deepwater area
in the northwestern Gulf of Mexico, Hidalgo Cruise
62-H-3, March, 1972 310
61 Density and dissolved oxygen profiles for a deep-basin
area in the northwestern Gulf of Mexico, Hidalgo Cruise
62-H-3, March, 1979 311
62 Geostrophic flow profile for a deep-basin area between
Stations 91 and 92, Hidalgo Cruise 62-H-3, March, 1972 312
63 The southern California Bight 324
64 Profiles illustrating morphological types of continental
margins off of western North America 326
65 Current meter data averaged from July 21 to
August 28, velocity units are in cm/sec. Regions of
southward flow are shaded 329
-------
66 Mean, maximum, and minimum temperatures at each
depth and during each deployment on the southern
California Shelf 332
67 Distribution of mean longshore currents on the Southern
California Shelf. A positive value corresponds to a
current to the north 333
68 Alongshore current at 40-m depth (55-m water depth) off
Point Loma, March, 1975, showing considerably different
flow conditions only a week apart 335
69 Distribution of current speeds - southern California
canyon, slope, and near-bottom 336
70 Annual temperature, salinity, dissolved oxygen, and
density distributions in the upper 200 m at CalCOFI
Station 90.28 337
71 Annual temperature, salinity, dissolved oxygen, and
density distributions in the upper 200 m at CalCOFI
Station 90.45 339
72 Representative Line 90 vertical sections for
temperature, salinity, and dissolved oxygen 340
73 Annual temperature, salinity, dissolved oxygen,
and density distributions in the upper 200 m at CalCOFI
Station 90.70 341
74 Physiographic provinces off northwest Pacific coast 357
75 Relative positions of major submarine banks and canyons
off Northwest coast 358
76 Continental margin (shelf and slope) profiles of the
Oregon and Washington coastlines 360
77 Monthly mean values of the alongshore component of the
currents off the Oregon coast 361
78 The vertical-offshore distribution of the maximum current
speeds observed during July and August, 1973, and during
February, March, and April, 1975, off Newport, Oregon 364
79 Onshore-offshore circulation pattern during summer
upwelling 365
80 Components of surface current vs. distance
offshore the Oregon coast 366
81 Current meter locations during 1973 368
-------
82 Summer (August 23, 1973) temperature, salinity,
and density profiles at Station Carnation (99 m).
Lat. 45° 14.7' N, Long. 124° 06.9' W 370
83 Winter (January 28, 1975) temperature and density
profiles at Station 2D (97 m). Lat. 45° 00.2' N,
Long. 124° 09.8' W 371
84 Mean current velocity profiles for Oregon continental
shelf locations in summer and winter 372
85 Mean seasonal variations on properties in the upper
30 m inside the 150-m isobath between 46° 50' and
47° 40' N Lat 373
86 Summer (August 24, 1973) temperature, salinity, and
density profiles at Station Edelweis (196 m).
Lat. 45° 15.3' N, Long. 124° 18.0' W 374
87 Winter (January 28, 1975) temperature, salinity, and
density profiles at Station 8D (218 m). Lat. 45°
01.2' N, Long. 124° 22.3' W 375
88 Mean current velocity profiles for Oregon upper-slope
locations in summer and winter 376
89 Summer (August 24, 1973) temperature, salinity, and
density profiles at Station Forsythia (492 m).
Lat. 45° 15.2' N, Long. 124° 39.81 W 377
90 Winter (January 29, 1975) temperature, salinity, and
density profiles at Station 19D (435 m). Lat. 45°
00.0' N, Long. 124° 16.0' W 378
91 Mean current velocity profiles for an Oregon mid-
slope location in summer and winter 379
92 Summer (August 24, 1973) calculated geostrophic current
profile, slope edge/basin location (Stations 390-391,
Figure 6-34) 381
93 Summer (August 24, 1973) temperature, salinity, and
density profiles at Station Gladiolus (1,412 m).
Lat. 45° 18.9' N, Long. 125° 00.1' W 382
94 Winter (January 29, 1975) temperature, salinity, and
density profiles at Station 16D (1,356 m). Lat. 45°
00.0' N, Long. 125° 12.0' W
383
xiv
-------
95 Offshore mean seasonal variations of properties in
the upper 100 m inside the area between 14° 30' -
47° 30' N Lat. and 126° 30' - 130° 30' W
Long., January, 1961 - March, 1962 384
96 Pacific Northwest Dungeness crab fishing areas 394
97 Washington pink shrimp fishing areas 396
98 Oregon pink shrimp fishing areas 397
99 Bathymetry of the Puna Canyon 403
100 Proposed and alternative dredged material
disposal sites 404
101 Stations used in the calculation of geostrophic
currents 406
102 Temperature, salinity, and density at Station
469/18, 20° 02' N, 154° 44' W, March 17, 1953 407
103 Geostrophic current profiles for waters northeast
of the Island of Hawaii 408
xv
-------
TABLES
Number £231
E-l Effects of Disposal Area on Factors Related to
Potential Impacts of Waste Disposal E-8
E-2 Evaluation of the Environmental Significance of
Disposal Area Options within each Representative
Disposal Area E-9
1 Marine Sanctuaries Names and Addresses 8
2 Responsibilities of Federal Departments and Agencies
for Regulating Ocean Waste Disposal Under MPRSA 14
3 EPA Regional Administrative Offices with Jurisdiction
over Selected States 15
4 NPDES Permitting Authority 20
5 NPDES Permitting Agencies 21
6 Estuarine Sanctuary Names and Addresses 33
7 State Agencies Responsible for Coastal Zone Management
Plans 35
8 Ocean Dumping Sites for Municipal and Industrial
Wastes 59
9 Dredged Material Ocean Disposal Site Locations and
Disposed Yardages for Calendar Year 1979 61
10 Types and Amounts of Ocean Disposal (in Approximate
Tons) 1973-1979 (Excludes Dredged Material) 63
11 Dredged Material Disposed of in 1979 64
12 Physical Characteristics of Rejects 80
13 Chemical Character of Rejects and Percent of
Original Input 81
14 Physical and Chemical Characteristics of Lime
Boil Solids 33
xvi
-------
15 Physical and Chemical Characteristics of Electro-
winning Solids 84
16 Physical Characteristics of Gasification Ash,
Combustion Ash, and Off-Gas Scrubber Solids 85
17 Chemical Characteristics of Combustion Ash
(Fly Ash) 86
18 Analysis of Reject Material From a Pilot Plant
Test of the Cuprion Process 89
19 Engineering Properties of Reject Material from a
Pilot Plant Test of the Cuprion Process 90
20 Results of an EP Toxicity Test Performed on
Rejects from a Pilot Test of the Cuprion Process
by the Bureau of Mines Avondale Research Center 91
21 Characteristics of Cuprion- and Reduction-
Ammonia Waste Streams 93
22 Characteristics of High Temperature Sulfuric
Acid Waste Streams 93
23 Characteristics of Smelting Waste Streams 94
24 Summary Comparison of Solid Phase Chemical
Composition, mg/kg 98
25 Summary Comparison of Dissolved Phase Chemical
Composition, ug/1 99
26 Comparison of Dissolved Metals Concentrations
to Water Quality Criteria for Marine Waters 101
27 Instantaneous Dump Characteristics for Selected
Site Locations within the Gulf of Mexico 109
28 Instantaneous Dump Characteristics for Selected
Site Locations in the Southern California Bight 116
29 Instantaneous Dump Characteristics for Pacific
Northwest Selected Site Locations Offshore of the
Coast 124
30 Instantaneous Dump Characteristics for Site
Locations Offshore of the Island of Hawaii 131
31 Summary of Potential Impacts of Inorganic Particulates
on Marine Fauna 150
xvi i
-------
32 A List of Environmental Considerations Related to
Marine Disposal of Manganese Nodule Processing Wastes
and Rejects 167
33 Disposal Options Considered for Evaluation of
Potential Effects of Reject Disposal 169
34 Effects of Disposal Area on Factors Related to
Potential Impacts of Waste Disposal 177
35 Evaluation of the Environmental Significance of Disposal
Area Options within each Representative Disposal
Area 179
36 London Dumping Convention Annex I 232
37 London Dumping Convention Annex II 233
38 London Dumping Convention Annex III 234
39 Values of K/HWf for Various Particle Fall
Velocities and Buoyance Frequencies 245
40 Examples of Marine Disposal Systems 263
41 Size Fractions of Tailings from Various Mines 266
42 Residual Metals in Recent Tailings Samples 267
43 Island Copper Mine Discharge Chemical Composition
of the Solid Phase (1977 Data) 271
44 Island Copper Mine Discharge Chemical Composition
of Liquid Fraction (1979 Data) 272
45 Size Distribution of Tailings Solids from the
Dascon and Bigacon Concentrators at Cebu, Philippines 275
46 Cumulative Curve Derivatives for the Analysis of
Sediment Near the Ma On Shan Disposal Area 281
47 Chemical Characteristics of Tailings and Sediments
from Railway Beach and Long Harbour 282
48 Yabulu Refinery Effluent Limitations for Discharge
to Halifax Bay, Australia 287
49 Metals Concentrations in Dredged Material Solids
Dumped at Sea - 1978 and 1979 293
50 Elutriate Analysis and Dredged Material Dumped
at Sea - 1978 and 1979 294
xvm
-------
51 Observed Composition of Used Drilling Muds
and Cuttings 295
52 References Consulted in Snythesizing the Physical
Oceanographic Characteristics of Western Gulf of
Mexico Disposal Areas 304
54 References Reviewed to Compile Physical Oceanographic
Information on Characteristic Disposal Areas in the
Southern California Bight 331
53 References Reviewed to Compile Physical Oceanographic
Information on Characteristic Disposal Areas Off the
Northwest Coast 367
55 Spawning Periods and Depths Inhabited by Principal
Groundfish Species off Washington and Oregon 399
56 Major Fish Species Caught in Waters Adjacent to
Hilo and Kona, Island of Hawaii, 1977 418
57 Depth Distributions of Hawaiian Bottomfishes 422
xix
-------
ACKNOWLEDGEMENT
We wish to acknowledge the contributions of the people who assisted in
the preparation of this report. Mr. Mike Williamson and Mr. Steve Lazoff,
formerly of Hydrotask, Inc., prepared the description of manganese nodule
processing rejects and wastes. Dr. Erdogan Ozturgut assisted with the
physical characterization of the ocean disposal regions and also provided
helpful general advice. Tetra Tech personnel who contributed to the report
include Dr. William Muellenhoff and Mr. Steve Gherini who contributed to the
physical characterization of ocean disposal regions. Mr. Larry Marx
prepared the legal and regulatory evaluation. Mr. A. Mills Sol date provided
the analysis of the dispersion of dumped materials. Dr. Lawrence McCrone
and Mr. Mic Griben prepared the biological characterization of ocean
disposal sites. Dr. Gordon Bilyard prepared the review of mining waste
disposal. Dr. Thomas Ginn supervised preparation of the biological portions
of the report and prepared the biological research recommendations.
Mr. Gary Bigham was project manager and prepared much of the report. The
authors wish to thank Dr. Jean Snider, NOAA contracting officer, for her
assistance and many helpful suggestions. We also thank Mr. Karl Jugel and
Dr. Amor Lane for their helpful advice and suggestions.
-------
EXECUTIVE SUMMARY
A single manganese nodule seabed mining operation is projected to
recover approximately 4 million metric tons3 per year (mty). Processing of
these nodules would occur at land-based processing plants. Such a facility
will probably be located in coastal areas or have ready access to the ocean
for waste disposal. Possible locations could be the western Gulf Coast,
southern California, the Pacific Northwest, or Hawaii. The option of land
disposal for manganese nodule processing rejects may not be available. The
option of ocean disposal may therefore be of great importance to the
development of an ocean mining industry.
PROCESSING WASTE
Manganese nodule processing techniques are hydrometal1urgical or
smelting/hydrometallurgical. These processes rely on chemical leaching of
the ground nodule (hydrometallurgical) or smelter matte
(smelting/hydrometallurgical) to remove metals such as cobalt, nickel,
copper, and molybdenum from the mineral matrix with which they are
chemically combined. Processing techniques can also be classified as three-
or four-metal processes. Three-metal processes recover copper, cobalt, and
nickel as the primary value metals. A four-metal process is designed to
also recover manganese. Figure E-l displays the three- and four-metal
processes and their rates of waste production.
The primary waste from nodule processing is a leached residue or
rejects from the hydrometallurgical processes and granulated slag from
smelting. Volumes of rejects for disposal are estimated at 2.7 to 3.5 x 10°
mty and 5.8 x 105 mty for granulated slag. This volume of rejects would
require from 1.8 to 2.4 dumps per day from a 4,900 metric ton capacity
barge. One barge of the same size would have to dump every 2.5 days to
dispose of the granulated slag. Other types of wastes are produced in a
processing plant but their volumes are much less than the rejects. These
other waste streams could be added to rejects or treated and disposed of
separately. Only the ocean disposal of rejects is evaluated in this report.
Manganese nodule processing rejects will be in the form of a slurry of
approximately 42 percent solids and density near 2.0. Particles will be
very fine grained. Tests on rejects from one pilot-scale plant showed 50
percent of the solids to be smaller than 6 micrometers (urn). Granulated
smelter slag is expected to have a much larger particle size, similar to
very coarse sand (1.7 mm).
a All values for nodule or reject tonnage are in dry tons unless otherwise
noted.
E-l
-------
DULES PROCESSED
» ^ b to b
L I 1 1 1
DNS SOLID WASTE/TON NO
3 — ro to A. yi c
1 1 1 1 1
~
_ _. _ ..
--
_ " ~. ~
-- --
- - -
- _ .
-T- -•
-. . .
- " -
- - -
_ __
_- - „ . _
—
--
. —
::::
::::
—
— - - ~
: : - :
• ---
_ _ - -, -
" : ; : : "
'::".. ~:.~~:
- - - -
— -
" :. - - - -
-
—
;::::
- -..- _ _ _ .
.. - -
- - - . _ -
—
- -
- - . — -
.. . .
'."::"
- --
—
REDUCTION/ SMELTING REDUCTION/ CUPRION/ HIGH-TEMP.
HYDROCHLORIC AMMONIACAL AMMONIA SULFURIC
ACID LEACH LEACH LEACH ACID-PROCESS
4 -METAL PROCESS 3 -METAL PROCESS
DATA FROM: Dames and Moore 19775
Figure E-l. Waste production rates for alternative manganese nodule processing
techniques.
-------
Chemically, the hydrometallurgical rejects will consist mostly of
either the carbonate or oxide of manganese, and the oxides of iron,
aluminum, and silicon. Granulated slag will be in the form of a vitreous
solid. Several heavy metals such as copper, chromium, cadmium, and mercury
will also be associated with the rejects, and their potential toxicity is of
concern. To be potentially toxic to marine organisms, metals must generally
be in a dissolved ionic form. Nearly all the metals associated with the
rejects are expected to be chemically combined in the solid phase or
adsorbed to particle surfaces. The. remaining dissolved metals fraction may
exist as dissolved complexes and not as the potentially toxic ionic species.
While available evidence supports the above general description of metals
partitioning, chemical tests and bioassays of representative rejects will be
necessary for qualitative conclusions.
OCEAN DISPOSAL
There are two primary means of disposing of manganese nodule processing
rejects to the ocean; pipeline discharge (outfall) and barge dumping.
Outfall discharge of rejects requires special siting requirements. The pipe
must discharge to a relatively steep slope so that the discharged solids
will move downslope and away from the pipe as a density flow. This option
is probably feasible only in southern California and Hawaii.
Barged wastes can be dumped through the bottom of the barge or pumped
out. The density of the reject slurry in the barge and how it is released
will have an important effect on the dispersion and ultimate fate of the
rejects. The other major variables are water depth and the density gradient
of the water column.
A simplified method has been developed in this report to predict the
distribution and concentration of rejects 4 hours after dumping. The 4-hour
period was selected because existing regulations call for determination of
dilution at the end of 4 hours. A second and perhaps more compelling reason
is that to follow advection and dispersion of solids to their point of
deposition on the bottom requires the use of a state-of-the-art model and is
not amenable to reasonable simplification. The method is useful to describe
the behavior of a descending cloud and dilution after 4 hours but should
only be used for relative comparisons. With the very fine-grained nature of
the solids, much of the material will still be in suspension near the bottom
after 4 hours and subject to future transport.
Estimates have been made of the dilution and dispersion of barge dumped
sediments using the simplified method. These estimates have been made for
nearshore, midshelf, and deepwater areas representative of conditions in the
western Gulf of Mexico, southern California, the Pacific Northwest, and
Hawaii. For the areas studied, water depths ranged from 44m (144 ft) to
over 3,000 m (9,800 ft). The dilutions after 4 hours range from 37:1 in
shallow water to over 50,000:1 in deep water. If all the solids settled
from the bottom cloud to the seabed at the end of 4 hours, the areas covered
would range from 0.01 km2 in shallow water to approximately 0.6 km2 in deep
water. As mentioned earlier, however, the full extent of the bottom area
E-3
-------
impacted by a dump would be larger but cannot presently be estimated within
the scope of this project.
Other disposal concepts which provide a range of containment or
dispersal of rejects could be utilized in addition to barge dumping or
outfall discharge. A barge or ship can be pumped out and rejects discharged
into the ship's wake to achieve maximum dispersion of the waste. Instead of
discharging to the surface, the rejects could be shunted through a pipe to a
depth below the euphotic zone. This would eliminate the possibility of
potential euphotic zone impacts. In water depths less than approximately
200m, rejects could possibly be shunted directly to the sea floor and
provide for maximum containment of rejects.
Rejects could possibly be formed into blocks and dumped nearshore to
form an artificial reef. Experiments with wastes from coal-fired power
plants suggest that environmental benefits could accrue from the presence of
the reef. Blocks of rejects from a three-metal process plant could be more
easily recovered if it were later decided to recover manganese. The
evaluation of the technical and economic feasibility of this alternative
needs extensive study.
CURRENT OCEAN DISPOSAL ACTIVITY
Several waste materials are currently dumped or discharged to marine
waters of the United States. In 1979, over 90 million tons of dredged
material were dumped at 50 different disposal sites. Also in 1979, nearly 6
million tons of sewage sludge and over 2.5 million tons of industrial wastes
were dumped in the Atlantic Ocean.
A total of 232 land-based facilities discharge wastes through outfalls
to U.S. coastal waters. These facilities are mostly municipal waste
treatment plants, industrial waste treatment plants, and electric generating
facilities discharging cooling water. There are also approximately 3,000
offshore oil and gas exploration and production platforms which discharge
drilling muds, cuttings, and other wastes.
For the Atlantic, Pacific, and Gulf coasts, over 3 billion gallons of
wastewater are discharged each day through marine outfalls. Approximately
360 tons of sewage sludge are discharged each day.
REGULATORY REQUIREMENTS
It appears that current water quality criteria can be met based upon
the projected composition of the rejects. Results of chemical analysis of
representative processing reject samples are currently not available. The
ultimate decision of acceptability for ocean disposal rests with the EPA in
the case of ocean dumping. No definitive guidelines exist, however, to
determine what degree of biological alteration is acceptable. This is
partly because the decision must also be based upon the availability of
alternative disposal methods. The final judgement is therefore site
specific.
E-4
-------
An outfall discharge of manganese nodule processing rejects must
currently comply with EPA's regulations for the National Pollutant Discharge
Elimination System (NPDES). Discharges to marine waters are addressed
specifically by Section 403(c) of the Clean Water Act. As with ocean
dumping, the 403(c) regulations do not by themselves provide a definitive
answer to the question of what degree of biological alteration is
acceptable. The 403(c) regulations must be applied on a case-by-case basis
to the facts concerning a particular marine discharge.
There appear to be no absolute regulatory obstacles to the ocean
discharge or dumping of manganese nodule processing rejects. It is
important to note however that this regulatory evaluation is based upon
existing regulations. With commercial scale mining and processing starting
in 1988 at the earliest, significant changes in the regulations may occur
before they are actually applied to a manganese nodule processing plant.
CHARACTERISTICS OF REPRESENTATIVE DISPOSAL AREAS
The western Gulf of Mexico, the southern California Bight, the Pacific
Northwest, and Hawaii are regions where a manganese nodule processing plant
might be located by virtue of proximity to the Pacific Ocean nodule mining
areas. The physical and biological characteristics of these regions have
been evaluated to provide the necessary framework for making general
predictions of expected impacts of rejects disposal.
Specific areas have been chosen within each region. The purpose of
selecting specific areas is to demonstrate how physical and biological
characteristics change with distance from shore and increasing water depth.
The areas selected generally represent nearshore, midshelf, and deep water
(seaward of the shelf) conditions.
In each of the regions considered, there is typically an
offshore-onshore gradient in biological productivity such that nearshore
areas are generally most productive. Consequently, most of the major
fisheries are located over the continental shelves. Demersal fisheries,
which are especially well developed on the continental shelves of the
Pacific Northwest and the Western Gulf of Mexico, are particularly
vulnerable to adverse impacts of the disposal of manganese nodule processing
wastes. Pelagic fisheries, which are the only fisheries in the open ocean,
and which are the dominant fisheries over the Hawaiian insular shelf and in
the southern California Bight, are less likely to be adversely affected by
the disposal of these wastes.
Certain shallow benthic habitats are potentially highly vulnerable to
impacts of the marine disposal of manganese nodule processing wastes. These
include coral reefs (which are extensively developed in nearshore waters
along the Kona coast of the island of Hawaii and exist as well on
hard-bottom banks on the outer continental shelf in the western Gulf of
Mexico), kelp beds (which flourish in certain nearshore areas of southern
California), and other hard-bottom banks having diverse subtidal benthic
communities (such as Cortes and Tanner Banks on the seaward portion of the
California continental borderland).
E-5
-------
The sensitivity of other benthic communities to adverse impacts of the
disposal of manganese nodule processing wastes can be expected to vary with
the type of natural substrate, the ambient physical/chemical environment,
the type of resident organisms, and with the rate of natural sedimentation.
Hence, there are important differences in the potential for adverse
ecological impacts between regions and between representative disposal areas
within each region. This potential for adverse impacts must be evaluated
for each area independently, in order to arrive at a decision of the most
appropriate disposal site for these wastes.
ENVIRONMENTAL CONSIDERATIONS
Based on a review of the documented effects of marine disposal of mine
tailings and other wastes, and on consideration of the limited information
on the potential characteristics of manganese nodule processing wastes, it
is expected that potential environmental effects of reject disposal may
include:
• Effects on primary production
• Direct toxic effects
• Effects on behavior and feeding of marine organisms
• Bi-oaccumulation
• Effects of substrate alteration
• Intertrophic effects.
Two of these, bioaccumul ation and effects of substrate alteration, are
expected to be of primary concern because of the potential area! extent of
effects, duration of effects, and involvement of commercial/recreational
species. Direct toxicity and effects on behavior and feeding have an
intermediate significance. The lowest relative significance is associated
with effects on primary production and intertrophic effects.
The expected occurrence of potentially toxic metals in manganese nodule
processing wastes suggests that bioaccumul ation of these metals within
marine organisms may be a serious consideration. Organisms may accumulate
metals through direct uptake of dissolved forms or through ingestion of
contaminated particles. Available evidence indicates that the amount of a
metal in the dissolved form is especially important in determining its
bioavailability. The metal-binding capacity of the rejects is currently
unknown, although the available evidence suggests that it will be high.
Further chemical analyses of the wastes would be necessary to evaluate the
potential for bioaccumulation of metals by marine organisms. Even if
bioaccumulation occurs, however, it is important to note that there is
little evidence to suggest that metals can be biomagnified within marine
food chains.
E-6
-------
An analysis of the effects of the marine disposal of mine tailings,
which have characteristics similar to those of the hydrometallurgical
process rejects, suggests that benthic (i.e., bottom dwelling) communities
may be obliterated by burial under deposits of manganese nodule rejects and
that recolonization may be slow due to the unnatural characteristics of
these wastes (e.g., change in sediment grain size, lack of organic content,
high concentrations of metals). Also, sublethal accumulations of rejects on
the sea floor may significantly alter benthic community composition and have
effects on marine food chains. Still smaller accumulations of rejects may
have negligible effects on benthic communities. The extent of deposition,
and therefore the nature of the impacts on benthic communities, may be
expected to vary with the receiving environment and with the method of
disposal. Of the potentially impacted biotic groups, benthic communities
have a higher significance because of the potential for extended exposure to
modified or contaminated sediments. Plankton and pelagic fishes are of
lesser significance because of limited exposure times, avoidance potential
(fishes), and recovery potential (plankton).
Factors important in determining the severity of potential impacts are
evaluated in Table E-l. Evaluation of possible disposal options indicates
that, considering the relative deposition rates and the potential
involvement of commercial/recreational species, the outfall and nearshore
dump options would have the greatest potential environmental impacts. The
lowest potential impacts are associated with the open ocean disposal options
(dump and dispersal). The relative environmental significance of the
disposal options varies according to biological and oceanographic
characteristics of the four representative disposal sites (Table E-2). For
nearshore disposal (outfall or dump), the relative environmental
significance is highest in the Pacific Northwest, intermediate in southern
California, and lowest in Hawaii. This ranking reflects the general
productivity, fisheries potential (especially demersal forms), and available
dilution/dispersal in each area. For shelf and deep ocean dispersal
options, the four areas have similar levels of environmental significance,
except for a higher relative significance for shelf disposal in the western
Gulf of Mexico.
It should be emphasized that each of the representative disposal areas
has specific environmental characteristics that can potentially alter the
relative ranking of disposal options based on generic considerations alone.
Moreover, there are most likely considerable differences in sensitivity to
impact among organisms associated with each representative disposal area.
Unfortunately, these differences in sensitivity are currently not
quantifiable. Thus, definitive assessments of potential impacts will
require baseline environmental studies, accurate characterization of
potential reject materials, and determination of the individual responses of
sensitive species to those materials.
E-7
-------
I
oo
TABLE E-l. EFFECTS OF DISPOSAL AREA ON FACTORS RELATED TO POTENTIAL
IMPACTS OF WASTE DISPOSAL
Disposal
Area
Nearshore
Shelf
Deep ocean
Relative
Deposition
Rate
High
Moderate
Low
Relative
Area
Affected
Limited
Moderate
Extensive
Potential
Dilution
Limited
Moderate
High
Relative
Organism
Sensitivities
Low
Moderate
High
Recovery
Potential
High
Moderate
Low
Trophic
Link with
Fisheries
High
Moderate
to high
Very
1 i mi ted
-------
TABLE E-2. EVALUATION OF THE ENVIRONMENTAL SIGNIFICANCE OF
DISPOSAL AREA OPTIONS WITHIN EACH REPRESENTATIVE DISPOSAL AREA
Nearshore
Outfall Dump Shelf Deep Ocean
Pacific
Northwest 43 2 1
Southern
California 33 2 1
Hawaii 22 N/A 1
Western Gulf
of Mexico N/A 3 1
Note: Each disposal option is ranked from 1 to 4, with a rank of 4
representing the greatest environmental significance.
E-9
-------
1. INTRODUCTION
During the past 15 years, deep ocean manganese nodules have been the
focus of a considerable research effort by government, industry, and
academia. Much of the interest in manganese nodules stems from their
potential as a new source for nickel, copper, cobalt, manganese, and
perhaps, molybdenum and other metals. Since the United States relies
totally upon foreign sources for nickel, cobalt, and manganese, and imports
substantial amounts of copper, development and utilization is of strategic
as well as economic significance.
Industry has demonstrated that commercial-scale recovery and processing
of deep ocean manganese nodules are technically feasible and is evaluating
commercial feasibility. Nodule mining and processing operations are
expected to commence as soon as economic and political conditions allow.
The provisions of the Deep Seabed Hard Minerals Resources Act allow
commercial-scale mining to commence in 1988.
NOAA has been investigating the potential environmental impacts of both
deep ocean mining and disposal of manganese nodule processing waste since
1975. NOA'A has most recently initiated a cooperative research program on
manganese nodule processing waste management in conjunction with the
U.S. Bureau of Mines, Environmental Protection Agency Criteria and Standards
Division and Office of Research and Development, and U.S. Fish and Wildlife
Service. The program consists of three projects:
• Analysis and Characterization of Potential Manganese Nodule
Processing Rejects
• State-of-the-Art Assessment of Onshore Disposal of Manganese
Nodule Rejects
• Evaluation of Ocean Disposal of Manganese Nodule Processing
Waste and Environmental Considerations.
The Analysis and Characterization of Potential Manganese Nodule
Processing Rejects project is sponsored by NOAA and is being performed by
the Bureau of Mines Avondale Research Center. The objective of this project
is to develop chemical and physical characterization of rejects from the
types of manganese nodule processing techniques representative of those
being developed by industry. Analyses are being performed on rejects
generated by pilot-scale processing plants.
The second project, State-of-the-Art Environmental Assessment of
Onshore Disposal of Manganese Nodule Rejects, is sponsored by the Bureau of
Mines and is being performed by Rogers, Golden, and Hal pern. The objectives
of this project are to identify state-of-the-art techniques for the onshore
-------
disposal of manganese nodule processing rejects and provide an assessment of
regulatory requirements and important environmental concerns at sites
representative of those likely to be chosen by industry.
This report presents the results of the third project within the
manganese nodule processing waste management program and addresses ocean
disposal. Discussion of the following topics is presented:
• Regulatory requirements
• Ocean disposal technologies
• Fate of ocean dumped material
• Current ocean disposal activity
• Characterization of nodule processing rejects
• Comparison of rejects to other wastes
• Physical and biological characteristics of representative
disposal areas
• Environmental considerations related to manganese nodule
processing rejects disposal
• Research and study requirements for assessing ocean disposal
of rejects.
-------
2. LEGAL AND REGULATORY REQUIREMENTS APPLICABLE TO
OCEAN DISPOSAL OF MANGANESE NODULE PROCESSING REJECTS
Until the passage of the first environmental legislation in the late
1960s, relatively little governmental or international effort was expended
regulating waste disposal in the marine environment. However, increasing
public awareness, coupled with political pressures concerning public health
and welfare and environmental preservation, led to the passage and
ratification of several federal laws and regulations governing waste
disposal.
Six major federal environmental laws may apply to manganese nodule
processing waste disposal. These are the Federal Water Pollution Control
Act (PL 92-500 as ammended), Safe Drinking Water Act (PL 93-253), Clean Air
Act (PL 93-319), Resource Conservation and Recovery Act (PL 94-580), Deep
Seabed Hard Mineral Resources Act (PL 96-283), and the Marine Protection,
Research, and Sanctuaries Act (PL 92-532). All of these laws require
permits for disposing, discharging, or dumping wastes into multimedia
environments (air, land, surface water, groundwater, and the oceans).
However, increasing concern, controversy and research associated with past
disposal practices (improper landfill ing, midnight dumping) and new
innovative technologies (stabilization, encapsulation) have been major
factors in the review of several waste management policies. In the United
States, many waste management policies are being reviewed and/or re-proposed
to consider other disposal options and intermediate trade-offs including but
not limited to ocean dumping, marine discharge, waste isolation in stable
geologic formations, stabilization, and encapsulation.
If industry elects to dispose of processing wastes in the ocean, it
must comply with the two major federal laws governing waste disposal at sea:
the Marine Protection, Research, and Sanctuaries Act (for ocean dumping) and
the Clean Water Act (for discharge through outfall pipes or discharges from
seabed mining vessels, or platforms). Numerous federal laws, such as the
Deep Seabed Hard Mineral Resources Act, the National Environmental Policy
Act, the Coastal Zone Management Act, the Fish and Wildlife Coordination
Act, the Endangered Species Act, the Marine Mammal Protection Act, and the
National Historic Preservation Act of 1966 also apply to the ocean disposal
of processing wastes but will not be discussed in detail here.
Three key terms used throughout this report include disposal, dumping,
and discharge. Disposal is a general term including both dumping and
discharge. Dumping is the transportation of wastes from shore, or from any
location by a U.S. flag vessel or aircraft, for the purpose of disposal, and
the release of such waste into the ocean. Discharge refers to wastes
released from a point source, other than a vessel, such as an outfall. For
this report, these terms all refer to the ocean environment and are
technically defined as follows:
-------
disposal - means the discharge, deposit, injection, dumping,
spilling, leaking, or placing of any solid waste or hazardous
wastes into or on any land or water so that such solid waste or
hazardous waste or any constituent thereof may enter the
environment or be emitted into the air or discharged into any
water, including groundwaters (40 CFR Part 260.3).
dumping - means a disposition of material: Provided, that it
does not mean a disposition of any effluent from any outfall
structure to the extent that .such disposition is regulated under
the provisions of the FWPCA, under the provisions of Section 13
of the River and. Harbor Act of 1899, as amended (33 U.S.C. 407),
or under the provisions of the Atomic Energy Act of 1954, as
amended (42 U.S.C. 2011), nor does it mean a routine discharge
of effluent incidental to the propulsion of, or operation of
motor-driven equipment on, vessels: Provided further, that it
does not mean the construction of any fixed structure or
artificial island nor the intentional placement of any device in
ocean waters or on or in the submerged land beneath such waters,
for a purpose other than disposal, when such construction or
such placement is otherwise regulated by Federal or State law or
occurs pursuant to an authorized Federal or State program; and
provided further, that it does not include the deposit of oyster
shells, or other materials when such deposit is made for the
purpose of developing, maintaining, or harvesting fisheries
resources and is otherwise regulated by Federal or State law or
occurs pursuant to an authorized Federal or State program (40
CFR Part 220.2).
discharge - (NPDES) when used without qualification means the
"discharge of a pollutant," which means:
(a)(l) Any addition of any "pollutant" or combination of
pollutants to "waters of the United States" from any
"point source," or (2) Any addition of any pollutant or
combination of pollutants to the waters of the
"contiguous zone" or the ocean from any point source
other than a vessel or other floating craft which is
being used as a means of transportation.
(b) This definition includes additions of pollutants
into waters of the United States from: surface runoff
which is collected or channelled by man; discharges
through pipes, sewers, or other conveyances owned by a
State, municipality, or other person which do not lead
to a treatment works; and discharges through pipes,
sewers, or other conveyances leading into privately
owned treatment works.
-------
This term does not include an addition of pollutants by any
"indirect discharger,"
OCEAN DUMPING
With increasing danger of marine pollution by ocean dumping of waste
materials, the President of the United States in April, 1970, directed the
Council on Environmental Quality to conduct a study of the problems and
alternatives to ocean dumping. This report (Senate Report 92-451, 1971)
concluded that although dumping was not a major source of pollution at
present, there was an immediate need for urgent action both at national and
international levels to prevent the problem of dumping from growing to a
great magnitude. As a follow-up to the report, the United States prepared a
draft legislation package to regulate the transportation for ocean dumping
at an international level * This draft on ocean dumping policy was intended
to provide the basis for a global convention on ocean dumping during the
United Nations Conference on the Human Environment scheduled for June of
1972.
London Dumping Convention
After much deliberation, an International Conference on Dumping at Sea
was held in London from October 30 to November 13, 1972. The conference was
attended by 82 states, with 12 other states and various international
organizations sending observers. After much debate, the conference adopted
a Convention on the Prevention of Marine Pollution by Dumping of Wastes and
Other Matter (referred to as the London Dumping Convention, the Convention,
or LDC) (see Appendix A for a summary of the Convention). Following receipt
of the required 15 ratifications or accessions, the London Dumping
Convention entered into force on August 30, 1975.
The London Dumping Convention is an international treaty requiring the
Contracting Parties to establish national systems to control vessels and
aircraft carrying substances leaving their shores for the purpose of being
disposed of at sea. It introduced a new element in international law on the
environments in that it is the responsibility of states to prevent damage
not only to the environment of other states but also to the environment of
areas beyond the limits of national jurisdiction. The Convention requires
each signatory state to establish an appropriate authority to issue permits,
keep records, and monitor activities. The United States, as a member of the
Convention, complies with the mandates and intent of the London Dumping
Convention through the guidelines and regulations established by EPA under
Title I of the Marine Protection Research and Sanctuaries Act.
Because the Convention was signed when the Third United Nations
Conference on the Law of Sea (UNCLOS III) was being prepared and UNCLOS III
was to deal with deep sea minerals, the London Dumping Convention did not
address at length the dumping of wastes resulting from the processing of
seabed mineral resources. Article 210 provides for the development by
individual states of rules and regulations for areas and persons subject to
its jurisdiction which should be no less effective than any rules developed
-------
collectively by a competent international organization or diplomatic
conference. The Law of the Sea Convention is scheduled for signing in
Caracas later this year. Many provisions including those dealing with
navigation, overflight, the continental shelf, marine research, and the
environment are constructive; however, Part XI governing mineral recovery
from the deep seabeds appears difficult to approve. Whether under the
London Dumping Convention or the Law of the Sea Convention, it is up to the
respective signatory state, to make decisions on the dumping of manganese
nodule processing wastes.
Marine Protection, Research, and Sanctuaries Act
Statutory Overview—
The Marine Protection, Research, and Sanctuaries Act of 1972 (MPRSA),
commonly known as the "Ocean Dumping Act," was developed to fill regulatory
gaps in the protection of the marine environment and public health and
welfare. The statute declares "it is the policy of the United States to
regulate the dumping of all types of materials into ocean waters and to
prevent or strictly limit the dumping into ocean waters of any material
which would adversely affect human health, welfare, or amenities, or the
marine environment, ecological systems or economic potentialities" (PL
92-532, October 23, 1972, 33 USC 1401). The Act is to regulate the
transportation by any person of material from the United States and, in the
case of United States flag vessels, aircraft, or agencies, the
transportation of material from a location outside the United States, when
in either case the transportation is for the purpose of dumping the material
into ocean waters, and the dumping of material transported by any person
from a location' outside the United States, if the dumping occurs in the
territorial seas or the contiguous zone of the United States. The
territorial seas are roughly defined as those waters lying within 3 miles of
a baseline (roughly the coastline) and the contiguous zone as those waters
lying between 3 and 12 miles seaward from the baseline. Thus, the MPRSA
mandates the EPA to administer and enforce the regulation of ocean dumping,
not only within the territorial seas and contiguous zone, but also within
international waters.
Title I of the MPRSA sets forth factors which need to be considered by
the Administrator of the EPA in the establishment and application of
criteria to be used in the evaluation of permit applications for ocean
dumping. These factors include:
A The need for the proposed dumping.
B The effect of such dumping on human health and welfare,
including economic, aesthetic, and recreational values.
C The effect of such dumping on fisheries resources, plankton,
fish, shellfish, wildlife, shorelines, and beaches.
-------
D The effect of such dumping on marine ecosystems,
particularly with respect to
1 the transfer, concentration, and dispersion of such
material and its byproducts through biological,
physical, and chemical processes;
ii potential changes in marine ecosystem diversity,
productivity, and stability; and
iii species and community population dynamics.
E The effect of dumping particular volumes and concentrations
of such materials.
F The persistence and permanence of the effects of the
dumping^
G Appropriate locations and methods of disposal or recycling,
including land-based alternatives and the probable impact of
requiring use of such alternate locations or methods upon
considerations affecting the public interest.
H The effect on alternate uses of the oceans, such as
scientific study, fishing, and other living resource
exploitation, and nonliving resource exploitation.
I In designating recommended sites, the Administrator shall
utilize, wherever feasible, locations beyond the edge of the
Continental Shelf (PL 92-532 October 23, 1972).
Under the Act, EPA is authorized to administer and enforce the entire
ocean dumping program and to issue permits regulating the dumping of all
materials except dredged materials, which are dumped under U.S. Army Corps
of Engineers permits issued consistent with EPA's marine environmental
impact eritenae
Title III of the Marine Protection, Research, and Sanctuaries Act of
1972 (MPRSA), as amended in 1980, authorizes the Secretary of Commerce with
Presidential approval to designate ocean waters as marine sanctuaries for
the purposes of preserving or restoring their conservation, recreational,
ecological, or aesthetic values. The marine sanctuaries program is intended
to prevent indiscriminate multiple use of specific areas that have special
values and uses. Site selection criteria for marine sanctuaries include
both resource and human-use values in an approach which accurately reflects
the intent of Congress in enacting this legislation. Sanctuaries may be
designated as far seaward as the outer edge of the continental shelf, in
coastal waters where the water ebbs and flows, or in the Great Lakes and
their connecting waters. Table 1 gives a listing of the six established
marine sanctuaries to date.
-------
TABLE 1. MARINE SANCTUARIES NAMES AND ADDRESSES
(AS OF APRIL, 1982)
Gray's Reef National Marine Sanctuary
(off Sapelo Island, Georgia)
(no manager appointed yet)
Georgia Department Natural Resources
Coastal Resources Division
1200 Glynn Ave.
Brunswick, GA 31523
(912) 264-7289
U.S.S. MONITOR National Marine Sanctuary
(off North Carolina)
Diana Lange, Sanctuaries Coordinator
North Carolina Department Cultural Resources
Division of Archives and History
Underwater Archaeology Branch
P.O. Box 58
Kure Beach, NC 28449
(919) 458-9042
Key Largo Coral Reef National Marine Sanctuary
(off Florida's John Pennecamp State Park)
Florida Department of Natural Resources
Crown Building
202 Blount St.
Tallahassee, FL 32304
(904) 488-1555
(on-site)
John C. Halas, Sanctuaries Biologist
c/o John Pennecamp State Park
U.S. Route 1
MM 102.5 (Oceanside)
P.O. Box 487
Key Largo, FL 33037
(305) 451-2770
Looe Key National Marine Sanctuary
(off Florida Keys)
Florida Department of Natural Resources
Crown Building
202 Blount St.
Tallahassee, FL 32304
(904) 488-1555
8
-------
TABLE 1. (Continued)
(on-site)
Will Sheftal, Manager
Bahia Honda State Recreation Area
U.S. Route 1, Box 782
Big Pine Key, FL 33043
(305) 872-3253
Channel Islands National Marine Sanctuary
(off Southern California)
(no manager appointed yet)
Channel Islands National Marine Sanctuary
c/o Channel Islands National Park
1901 Spinnaker Ur,
Ventura, CA Q3001
(805) 644-8ib/
Point Reyes-Farallon Islands National Marine Sanctuary
(off north central California)
Peter Gogan, Manager
Point Reyes National Marine Sanctuary
c/o Point Reyes National Seashore
Point Reyes, CA 94956
(415) 663-8017
-------
Regulatory Process—
Regulations promulgated under Title I, Section 102 of the MPRSA were
first issued by EPA in 1973. The final ocean dumping regulations were
updated by EPA in January, 1977 (Federal Register, January 11, 1977). They
are currently being considered for another revision due to advances in
scientific knowledge and operational experience.
Existing Regulations--
EPA has set up a regulatory approach to ocean dumping with several
levels of control. All materials to be dumped in the ocean require a
permit. Except for those wastes generally approved for dumping, all wastes
must meet the need, environmental, economic, and social impact criteria set
out in 40 CFR Part 227. The burden of proof rests with the applicant to
indicate that the disposition of materials seaward of the baseline will not
unduly degrade or endanger the marine environment. The criteria used to
evaluate proposed dumping are applied on a case by case basis from
information available to the applicant, EPA, or the Corps of Engineers.
Specific criteria form the basis for the applicant to show that the
proposed disposal of material does not have significant adverse
environmental impacts. EPA has established regulations to evaluate
materials by categories. Manganese nodule processing wastes are most likely
to be classified in one of the following three categories:
1. Prohibited materials (40 CFR Part 227.5) - The dumping of
the following materials is prohibited and a permit will not
be approved of under any circumstances:
• High-level radioactive wastes
• Materials produced or used for radiological, chemical, or
biological warfare
• Persistent inert synthetic or natural materials which may
float or remain in suspension in such a manner that might
interfere with fishing, navigation, or other uses of the
ocean
0 Materials insufficiently described by the applicant to
effectively evaluate the application on the basis of the
environmental impact criteria.
It is unlikely that manganese nodule processing rejects will
fall into the prohibited category unless the composition and
properties of the waste are insufficiently known.
2. Constituents prohibited as other than trace contaminants (40
CFR Part 227.6) - Materials containing the constituents
below, which are prohibited other than as trace
10
-------
contaminants, require detailed characterization and
quantification:
• Mercury and its compounds
t Cadmium and its compounds
• Organohalogens
• Oil and greases
t Known or suspected carcinogens, mutagens, or teratogens.
The term "trace contaminants" was initiated to agree with
the London Dumping Convention. It is described as those
quantities that are in such form and amount that the dumping
will not cause significant undesirable effects, including
the possibility of their bioaccumulation in organisms. To
determine those quantities, bioassay and bioaccumulation
testing methods have been developed which are consistent
with an ecosystem approach and yield more accurate
assessments of the materials impact than comparing total
amounts of specific constituents with arbitrary ambient
values. Bioassay procedures are used to set the "limiting
permissable concentration" that makes up the monitoring
parameter for specific constituents.
Trace contaminants listed above, or any other toxic waste
(under 40 CFR Part 227.8) cannot exceed its limiting
permissable concentrations. The definition of limiting
permissable concentration is critical to application of the
regulations. Liquid, suspended particulates, and solid
phases of the material proposed for ocean dumping each have
a limiting permissable concentration for the particular
constituent determined by its effect on the marine
environment.
The specific bioassay requirements do not apply if the
applicant can demonstrate that the constituents are present
in a form that is non-toxic a.nd non-bioaccumulative to the
marine environment, or will be rapidly rendered so in the
marine environment by biological or chemical degradation.
EPA has great leeway in the identification of trace
contaminants and their allowable concentrations. Potential
toxic constituents are dealt with on a case by case basis
following bioassay procedures outlined in manuals published
by EPA and the Corps of Engineers.
It is likely that disposal of manganese nodule tailings will
have to comply with these requirements because nodules are
known to contain trace amounts of mercury and cadmium.
11
-------
These elements are inert in the nodules, but if the
processing techniques convert them to soluble compounds or
significantly increase their concentration in the solid
phase, ocean dumping may be prohibited. Under 40 CFR Part
227.12, "solid wastes consisting of inert natural minerals
or materials compatible with the ocean environment may be
generally approved for ocean dumping provided they are
insoluble above the applicable trace or limiting permissible
concentrations and are rapidly and completely settleable,
and they are of a particle size and density that they would
be deposited or rapidly dispersed without damage to benthic,
demersal, or pelagic biota."
Chapter 5 of this report provides a characterization of the
manganese nodule processing waste. It is most likely that
these wastes would come within the "Strictly Regulated
Dumping" category of the London Dumping Convention (see
Annex II) and within the "trace constituents" or "other
limited materials" categories under the MPRSA.
3. Other limited materials (40 CFR Part 227-7) - Some materials
have specific limitations in their concentrations and
impacts. They include:
• Liquid waste constituents immiscible or slightly soluble
in water, such as benzene, xylene, carbon disulfide, and
toluene, may be present only below their solibility
limits in seawater, as long as they do not interact with
ocean water to form insoluble materials
t Radioactive wastes, if not prohibited as high-level
radioactive waste, must be safely containerized
• Wastes containing living organisms are prohibited if the
organisms would endanger human or domestic animals health
• Highly acidic or alkaline wastes require special care
which includes demonstrating that the waste cannot change
the total acidity or alkalinity of the ocean water by
more than 10 percent
• Biodegradable wastes which consume oxygen may be dumped
only in quantities which will not depress normal
dissolved oxygen levels by more than 25 percent.
In addition to the above classifications and environmental impact
criteria, the applicant must demonstrate the necessity for dumping and
potential adverse effects on other uses of the ocean. Other criteria the
applicant must meet include:
12
-------
1. Need for ocean dumping (40 CFR Parts 227.14-227.16) - The
applicant must indicate that other options (i.e., landfill,
recycle, storage, landfarm, incineration, etc.) and their
environmental and economic costs have been considered. The
need for ocean dumping will not be considered to have been
demonstrated unless it is indicated that there are no
practicable alternative locations and methods of disposal or
re-use available which have less adverse environmental
impact or potential risk to other parts of the environment
than ocean dumping. It has been suggested that possible
uses of nodule wastes could be landfilling on undesireable
land, landfarming and recycling for fertilizer uses. These
need to be looked at closely before any permit is approved.
2. Impact or aesthetic, recreational, and economic values (40
CFR Part 227.17) - The applicant must demonstrate that there
is no potential for impacting or affecting beaches or
shorelines, commercial fishing, or municipalities or other
industries.
3. Impact on other uses of the ocean (40 CFR Part 227.20) - It
must be shown that the dumping of the nodule wastes has no
adverse effects on other uses of the ocean and coastal areas
(i.e., scientific research, oil and gas exploration,
transportation and navigation). The two major areas of
concern here are ocean transportation and fishing.
The objective of these additional criteria is to ensure that there is
consideration of economic and social factors in the decision to allow ocean
dumping.
EPA's regulatory approach to the ocean dumping program consists of site
designation, permitting, and surveillance and enforcement. Site designation
includes geographic placement of the site, waste dispersal characteristics
and interference with other uses of the ocean. The parameters used in
designating, and monitoring dump sites include location, depth, currents
water quality, potential accumulation of constituents, past activities at
site and existing ambient data both chemical and biological. Both EPA and
NOAA (administers Title II of MPRSA, Ocean Research and Monitoring) take the
responsibility for researching and monitoring the dump sites. EPA
designates site while surveillance, enforcement notice, and safe waste
transport responsibilities are under the authority of the U.S. Coast Guard.
Responsibilities of other federal departments and agencies involved in the
ocean waste disposal program under the MPRSA are shown in Table 2.
Ocean dumping permits are issued by both the Corps of Engineers or EPA
(with authority delegated to District Engineers or Regional Administrators,
see Table 3) for dredged and nondredged material, respectively. These
permits require submission of detailed engineering studies and studies
outlining the alternatives to ocean dumping. For material other than dredge
spoils, the applicant must also submit a compliance schedule to implement an
13
-------
TABLE 2. RESPONSIBILITIES OF FEDERAL DEPARTMENTS AND
AGENCIES FOR REGULATING OCEAN WASTE DISPOSAL UNDER MPRSA
Department/Agency
Responsibility
U.S. Environmental Protection Agency
U.S. Department of the Army Corps
of Engineers
U.S. Department of Transportation
Coast Guard
U.S. Department of Commerce
National Oceanic and Atmospheric
Administration
U.S. Department of Justice
U.S. Department of State
Issuance of waste disposal permits,
other than for dredged material
Establishment of criteria for regu-
lating waste disposal
Enforcement actions
Site designation and management
Overall ocean disposal program
management
Research on alternative ocean
disposal techniques
Issuance of dredged material
disposal permits
Recommending dredged material
disposal site locations
Surveillance
Enforcement support
Issuance of regulations for disposal
vessels
Review of permit applications
Long-term monitoring and research
Comprehensive ocean dumping impact
and short-term effect studies
Marine sanctuary designation
Court actions
International agreements
14
-------
TABLE 3. EPA REGIONAL ADMINISTRATIVE OFFICES WITH
JURISDICTION OVER SELECTED STATES
Alaska, Oregon, Washington
EPA Region X
1200 Sixth Avenue
Seattle, Washington
(206) 442-1220
FTS/339/1220
98101
California, Hawaii
Texas, Louisiana
EPA Region IX
215 Fremont Street
San Francisco, California
(415) 974-8076
FTS/454/8076
EPA Region VI
1201 Elm Street
Dallas, Texas 75270
(214) 767-7341
FTS/729/7341
94105
15
-------
environmentally acceptable alternative disposal method before December 31,
1981, or demonstrate that no feasible alternative exists and the waste to be
dumped is in full compliance with EPA's criteria by December 31, 1981. The
regulations under 40 CFR Part 220.3 describe the six categories of permits.
These permit types include:
1. General permits - for disposal of small quantities of
material which have minimal adverse environmental impacts
when dumped under prescribed conditions.
2. Special permits - for materials that satisfy the criteria,
but valid only up to 3 years. Holders of special permits
are not subject to the 1981 deadline for cessation of the
ocean disposal of harmful wastes. It is most likely that
manganese nodule processing wastes would require a special
permit for dumping since similar waste types as acid iron
wastes and industrial wastes have been approved.
3. Emergency permits - for materials which pose an unacceptable
risk relating to human health and for which there is no
other feasible alternative. These permits are issued on a
limited, case by case basis.
4. Interim permits - these permits which are valid for a
maximum of 1 year are issued when the applicant does not
demonstrate compliance of the waste with the environmental
impact criteria, but can demonstrate that the need for ocean
disposal is of greater significance to the public than
possible adverse environmental impacts. However, interim
permits can not be issued to applicants who were not issued
dumping permits before April 23, 1978. Holders of present
permits must have a compliance schedule which will ensure
either the complete phaseout of the activities by December
31, 1981. Thus, interim permits as presently stated do not
apply to the dumping of manganese nodule wastes.
5. Research permits - for dumping material into the ocean as
part of a research project, when scientific merit outweighs
the potential impacts (i.e., in 1979 a permit was granted
for oil dispersant studies). It is possible that initial
permits for ocean dumping of nodule processing wastes from
pilot plants during feasibility studies will fall under this
category.
6. Incineration at sea permits - not applicable.
Applications for any of these permits must include all information
necessary to evaluate the application. They must include general
information, detailed physical and chemical analyses of the wastes, bioassay
or other test results required to apply the impact criteria, the proposed
dumpsite, times and amounts of material to be dumped, description of the way
16
-------
in which this material has previously been disposed of, identification of
the process or activity generating the wastes, the method of release of the
materials, and an assessment of the environmental impact of the proposed
dumping.
According to EPA regulations (40 CFR Part 222.1), "Final action on any
application for a permit will, to the extent practicable, be taken within
180 days from the date a complete application is filed." However, the
nature of the public review process is such that there is no guarantee that
a permit will be granted in that time, if at all. A flow diagram of current
permitting procedures for ocean dumping is shown in Figure 1.
Current Status--
The regulatory process has been fairly successful to date relative to
the objective of eliminating ocean dumping. Of approximately 150 industrial
ocean dumpers in 1973, only 13 remain as of April, 1979 (EPA 1980a).
Excluding the Allied Chemical Corporation, NL Industries Incorporated, and
E.I. duPont de Nemours, all of the remaining industrial ocean dumpers in the
New York Bight and Puerto Rico areas have enforceable compliance schedules
within their permits which specify the cessation of ocean dumping by the end
of 1981.
So far the EPA has not had to make a permit decision on the economic
reasonableness of land-based alternatives. They have been granting or
denying permits based upon the environmental criteria. However, the general
opinion of the industrial ocean dumpers is that even in a situation where
the environmental impact criteria are not met or where a land-based
alternative to ocean disposal has a lower overall environmental impact than
ocean dumping, economics need to be considered and factored into the
decision to grant or deny a permit.
This approach has also been encouraged by the National Advisory
Committee on Oceans and Atmosphere (NACOA). A NACOA report entitled "The
Role of the Ocean in a Waste Management Strategy, January 1981" states that
the ocean is the best disposal option for certain waste material, and that
the United States policy should be to dispose of wastes in the most
environmentally sound manner, without granting special protection to a
particular medium. NACOA further states that even if the risk were somewhat
greater for ocean disposal, significantly disproportionate costs could
justify the granting of an ocean dumping permit.
This viewpoint was recently supported in a court decision ruling that
the Marine Protection, Research, and Sanctuaries Act did not authorize EPA
to ban the dumping of New York City sludge in the New York Bight without
considering the alternatives to ocean dumping. The District Court ordered
that EPA revise its ocean dumping regulations to require a balancing of all
the statutory factors including costs and the need for dumping against
environmental harm in each case [U.S. District Court for Southern District
of New York, City of New York vs. U.S. EPA, 80 Civ. 1677 (ADS), August 28,
1981].
17
-------
oo
EXCEPTIONS TO
CONCIOS10NS
OF EAW ANO
RECOMMENDATIONS
COMMENTS AND
E«CEPTIONS TO
ANOTHER PANTIES
EXCEPTIONS
ADMINISTRATOR
OR REGIONAL
ADMINISTRATOR
DETERMINATION
OH CASE
Figure 1. Flow diagram of current permitting procedures for ocean dumping.
-------
OCEAN DISCHARGE
An alternative to ocean dumping or land disposal of manganese nodule
processing wastes is the discharge of these materials directly to the ocean
by the means of an ocean outfall. An ocean outfall is defined as any point
source from which pollutants are discharged into the territorial sea,
contiguous zone or the ocean. Ocean discharge of point source pollutants is
regulated under the authority of the Clean Water Act (PL 95-217), amending
the Federal Water Pollution Control Act (PL 92-500). Section 402 of the
Clean Water Act, establishing the National Pollutant Discharge Elimination
System, and Section 403 of the Clean Water Act governing ocean discharges,
are of primary importance when considering ocean discharge of manganese
nodule processing wastes. The Clean Water Act and its associated
regulations govern ocean discharges from both land based processing
facilities and those facilities discharging at sea through an ocean outfall
from either a platform or processing vessel.
Clean Water Act
The Clean Water Act is the principal statutory authority regulating the
discharge of pollutants to the navigable waters of the United States
(including the territorial sea), the contiguous zone, and the oceans.
Section 402 of the Clean Water Act establishes the National Pollution
Discharge Elimination System (NPDES) permit program. Section 403(c)
addresses specifically the criteria to be used in evaluating NPDES permits
for point source discharges to the territorial sea, the contiguous zone and
the oceans. The regulations for the NPDES permit program and the criteria
for ocean discharge are promulgated under EPA's Consolidated Permit Program
and can be found in 40 CFR Parts 122, 124, and 125.
Section 402 - NPDES Permits —
The NPDES permit program is administered either by EPA or by a state
agency under an EPA-approved program. Table 4 indicates those states with
approved NPDES programs. NPDES requirements under the EPA program and an
approved state program are basically the same, but each state should be
contacted regarding specific requirements in their regulations and
application procedures. A state NPDES program will only apply to discharges
within the territorial waters of the state. Discharges to the contiguous
zone or oceans could be allowed only under a permit issued by the
appropriate EPA region (see Table 5). The appropriate NPDES application
forms can be obtained from EPA regional offices or the responsible state
agency.
Pursuant to Sections 301, 304(b) and (c), 306(b) and (c), and 307(c) of
the Clean Water Act, as amended, New Source Performance Standards (NSPS) and
effluent limitation guidelines representing effluent reduction attainable by
19
-------
TABLE 4. NPDES PERMITTING AUTHORITY
State State EPA
Alaska x
California x
Hawaii x
Louisiana x
Oregon x
Texas x
Washington x
20
-------
TABLE 5. NPDES PERMITTING AGENCIES
Alaska EPA Region X
1200 6th Avenue
Seattle, WA 98101
(206) 442-1220
FTS/339/1220
California3 Issued by Regional Water Quality Control
Boards - Approved by the State Water
Resources Control Board
State Water Resources Control Board
P.O. box 100
Sacramento, CA 95801
(916) 322-8353
Regional Water Quality Control Boards
North Coast Region (1)
1000 Coddingtown Center
Santa Rosa, CA 95401
(707) 545-2620
San Francisco Bay Region (2)
1111 Jackson St., Room 6040
Oakland, CA 94607
(415) 464-1155
Central Coast Region (3)
1122-A Laurel Lane
San Luis Obispo, CA 93401
(805) 549-3147
Los Angeles Region (4)
107 S. Broadway, Room 4027
Los Angeles, CA 90012
(213) 620-4460
Santa Ana Region (8)
6809 Indiana Avenue
Riverside, CA 92506
(714) 684-9330
San Diego Region (9)
6154 Mission Gorge Rd., Suite 205
San Diego, CA 92120
(714) 286-5114
21
-------
TABLE 5. (Continued)
Hawaii3 State of Hawaii Department of Health
Pollution Technical Review Branch
645 Halekauwila St.
Honolulu, HI 96813
(808) 548-6410
Louisiana13 EPA Region VI
1201 Elm Street
Dallas, TX 75270
(214) 767-7341
FTS/729-7341
Oregon0 Department of Environmental Quality
522 S.W. Fifth Avenue
P.O. Box 1760
Portland, OR
Texasb EPA Region VI
1201 Elm Street
Dallas, TX 75270
(214) 767-7341
FTS/729-7341
Washington0 Department of Ecology
Olympia, WA 98504
(206) 753-0211
a EPA Region IX issues NPDES permits for the contiguous zone and oceans off
of California and Hawaii.
b EPA Region VI issues NPDES permits for the contiguous zone and oceans off
of Louisiana and Texas.
0 EPA Region X issues NPDES permits for the contiguous zone and oceans off
of Oregon, Washington, and Alaska.
22
-------
the application of "best practicable control technology currently available"
(BPT), "best available technology economically achievable" (BAT), and "best
conventional pollutant control technology" (BCT), have been promulgated for
certain industrial categories. Manganese nodule processing is not covered
by any of the existing industrial categories or standards. In the absence
of existing standards, a NPDES permit will be evaluated using best
professional or engineering judgement (BPJ or BEJ). The permitting agency
will gather information from available sources to evauate the permit and
discharge impacts. The applicant must verify that state water quality
standards will be met and that the discharge will be consistent with the
state's coastal zone management program.
In the case of a NPDES ocean discharge permit, the applicant must also
first meet any more stringent requirements under the 403(c) ocean discharge
criteria.
Section 403(c) - Ocean Discharge Criteria--
Section 403(c) of the Clean Water Act provides the statutory authority
to establish guidelines for the issuance of National Pollutant Discharge
Elimination System (NPDES) permits for the discharge of pollutants from a
point source into the territorial seas, the contiguous zone, and the oceans.
Under the Clean Water Act (Section 502) these terms are defined as
follows:
• Territorial seas means the belt of the seas measured from
the line of ordinary low water along that portion of the
coast which is in direct contact with the open sea and the
line marking the seaward limit of inland waters, and
extending seaward a distance of three miles
• Contiguous zone means the entire zone established or to be
established by the United States under article 24 of the
Convention of the Territorial Sea and the Contiguous Zone
• Ocean means any portion of the high seas beyond the
contiguous zone.
The guidelines are promulgated under Title 40 CFR, Part 125.120-125.124.
The regulations were published in the Federal Register on October 3, 1980.
The statutory requirements of Section 403(c) directed the Environmental
Protection Agency to promulgate guidelines which would evaluate:
• The effect of disposal of pollutants on human health or
welfare, including but not limited to plankton, fish,
shellfish, wildlife, shorelines, and beaches
23
-------
• The effect of disposal of pollutants on marine life
including the transfer, concentration, and dispersal of
pollutants on their byproducts through biological, physical,
and chemical processes; changes in marine ecosystem
diversity, productivity, and stability; and species and
community population changes
• The effect of disposal of pollutants on aesthetic,
recreation, and economic values
• The persistence and permanence of the effects of disposal of
pollutants
• The effect of the disposal at varying rates, of particular
volumes and concentrations of pollutants
• Other possible locations and methods of disposal or
recycling of pollutants including land-based alternatives
• The effect of alternate uses of the oceans, such as mineral
exploitation and scientific study.
The regulatory standards and criteria developed under these guidelines
charge the permit writing agency with the responsibility of determining
whether a proposed discharge will cause "unreasonable degradation." The
determination will be based on available information concerning the
discharge area and the proposed material to be discharged. The permitting
agency may be able to use some mitigating conditions to prevent or
ameliorate degradation, or if they can't get enough information to make a
determination they shall prescribe a monitoring program that will require
the permittee to obtain the needed information. "Unreasonable degradation"
of the marine environment is defined (45 FR Vol. 194, p. 65953) to mean:
• Significant adverse changes in ecosystem diversity,
productivity and stability of the biological community
within the area of discharge and surrounding biological
communities,
• Threat to human health through direct exposure to pollutants
or through consumption of exposed acquatic organisms, or
t Loss of aesthetic, recreational, scientific or economic
values which is unreasonable in relation to the benefit
derived from the discharge.
Factors in determining unreasonable degradation to be considered by the
permit writing agency include:
• The quantities, composition and potential for
bioaccumulation or persistence of the polluants to be
discharged in the environment
24
-------
• The potential transport of such polluants by biological,
physical, or chemical processes
• The composition and vulnerability of the biological
communities which may be exposed to such pollutants
including the presence of unique species or communities of
species, the presence of species identified as endangered or
threatened pursuant to the Endangered Species Act, or the
presence of these species critical to the structure or
function of the ecosystem, such as those important for the
food chain
• The importance of the receiving water area to the
surrounding biological community, including the presence of
spawning sites, nursery/forage areas, migratory pathways, or
areas necessary for other functions or critical stages in
the life cycle of an organism
• The existence of special aquatic sites including, but not
limited to marine sanctuaries and refuges, parks, national
and historical monuments, national seashores, wilderness
areas and coral reefs
• The potential impacts on human health through direct and
indirect pathways
• Existing or potential recreational and commercial fishing,
including finfishing and shellfishing
• Any applicable requirements of an approved Coastal Zone
Management Plan
• Such other factors relating to the effects of the discharge
as may be appropriate
• Marine water quality criteria developed pursuant to Section
304(a)(l) of the Clean Water Act (PL 95-217).
Those discharges in compliance with Sections 301(g), 301(h), or 316(a)
variance requirements of the Clean Water Act, or in compliance with state
water quality standards shall be presumed not to cause unreasonable
degradation of the marine environment, for any specific pollutants or
conditions specified in the variance or standard.
In order to make the unreasonable degradation determination, the permit
writing agency may require from the applicant the following information, as
well as any other pertinent information:
• An analysis of the chemical constituents of any discharge
25
-------
t Appropriate bioassays necessary to determine the limiting
permissible concentrations for the discharge
• An analysis of initial dilution
• Available process modifications which will reduce the
quantities of pollutants which will be discharged
• Analysis of the location where pollutants are sought to be
discharged, including the biological community and the
physical description of the discharge facility
t Evaluation of available alternatives to the discharge of
pollutants including an evaluation of the possibility of
land-based disposal or disposal in an approved ocean dumping
site.
Figure 2 illustrates the decision process to be followed by the NPDES
permitting agency based upon the agency's determination of unreasonable
degradation. A finding of unreasonable degradation compels the agency to
revoke an existing permit or to deny a new discharge application. A finding
of no unreasonable degradation allows permit issuance or renewal, with any
necessary conditions as determined by the permitting agency.
In many cases, it is anticipated that the permitting agency will not
have sufficient information to make a conclusive determination of
unreasonable degradation based upon existing information. In these cases,
no discharge will be allowed to occur unless the permitting agency
determines that:
1. The discharge will not cause "irreparable harm" to the
marine environment while further evaluation is undertaken
2. There are no reasonable alternatives to the discharge
3. The discharge will comply with certain mandatory conditions.
Permit conditions will require that a discharge of pollutants following
dilution as measured at the boundary of the mixing zone not exceed the
limiting permissible concentration for the liquid and suspended particulate
phases of the waste material as described in Section 227.27(a){2) and (3),
Section 227.27(b) and (c) of the Ocean Dumping Criteria, and not exceed the
limiting permissible concentration for the solid phase of the waste material
or cause an accumulation of toxic materials in the human food chain as
described in Sections 227.27(b) and (c) of the Ocean Dumping Criteria.
Additional requirements may include a monitoring program, analysis of
bioaccumulative/persistent impact on aquatic life, and performance of liquid
or suspended particulate phase bioaccumul ation tests. The "mixing zone11 is
defined under the Ocean Discharge Criteria [40 CFR Part 125.121(c)] as the
zone extending from the sea's surface to seabed and extending laterally to a
distance of 100 meters in all directions from the discharge point(s), or as
26
-------
ro
PERMIT ISSUED
WITH ANY
NECESSARY
CONDITIONS
DETERMINATION
OF
UNREASONABLE
DEGRADATION
NO
DISCHARGE
PERMIT
UNDECIDED
CAUSE
IRREPARABLE
HARM?
YES
NO
DISCHARGE
PERMIT
NO
DISPOSAL
ALTERNATIVES?
CONDITIONAL
PERMIT
ISSUED
YES
NO
DISCHARGE
PERMIT
Figure 2. NPDES permit agency decision process for 403(c) evaluations
-------
the boundary of the zone of initial dilution as calculated by a plume model
approved by the director, whichever is greater, unless the director
determines that the more restrictive mixing zone or another definition of
the mixing zone is more appropriate for a specific discharge. The LPC of
the liquid phase is the concentration of the pollutant in the receiving
water, after allowances for initial mixing (as defined in 40 CFR Part
227.29), which will not exceed a toxicity threshold of 0.01 of the
concentration shown to be acutely toxic to appropriate marine organisms by
an EPA approved bioassay procedure. An alternative application factor other
than 0.01 can be used in calculating the LPC for liquid phase material if it
can be demonstrated to be scientifically supported.
Where the discharge contains suspended particulates and/or solid phase,
the applicant will be required to show that the LPC for the suspended
particulate and/or solid phase is not exceeded in accordance with Sections
227.27 (b), (c), and (d) of the existing Ocean Dumping Criteria (40 CFR
227). The LPC for these phases is defined as that concentration which will
not cause unreasonable acute or chronic toxicity or other sublethal adverse
effects based on bioassay results using appropriate marine organisms, or
that concentration which will not cause accumulation of toxic materials
throughout the human food chain.
Applicants may submit bioassay analyses performed on other wastes in
place of bioassay test results on their particular effluent, if the
applicant provides documentation to show that the composition of the waste
analyzed typifies that which the applicant is discharging or intends to
discharge. When the information is not otherwise available, the applicant
will be required to determine the LPC in accordance with procedures
described in Bioassay Procedures for the Ocean Disposal Permit Program
(U.S. EPA 1978), and in Ecological Evaluation of Proposed Discharge of
Dredge Material into the Ocean Waters (EPA/COE 1977).
Additional mandatory requirements of an NPDES permit, in those cases
where sufficient information is not available to make a conclusive
determination of unreasonable degradation, shall include the establishment
of a monitoring program to assess the impact of the discharge on water,
sediment, and biological quality. Other conditions which may be required of
any NPDES ocean discharge permit include bioaccumulation tests, seasonal
restrictions, and process modification.
All NPDES permits issued under the 403(c) guidelines can be modified or
revoked at any time on the basis of new data indicating that continued
discharge may cause unreasonable degradation of the marine environment.
. Dischargers applying for an NPDES permit under Section 403(c) must
still comply with all other requirements of the Clean Water Act, including
applicable technology-based requirements specified by Sections 301, 304, or
306 and water quality based limitations specified by Sections 303 or 307.
28
-------
OTHER REGULATORY PROGRAMS INVOLVED
The primary statutes applicable to waste disposal at sea have been
discussed in detail. However, numerous other federal laws may apply to
ocean disposal of processing wastes and may impact project lead times.
These laws include the Deep Seabed Hard Mineral Resources Act, the National
Environmental Policy Act, the Coastal Zone Management Act, the Fish and
Wildlife Coordination Act, the Endangered Species Act, the Marine Mammal
Protection Act, and the National Historic Preservation Act of 1966, and
merit full consideration at the earliest stages of project planning.
Deep Seabed Hard Mineral Resources Act
The Deep Seabed Hard Mineral Resources Act (Act), the governing
domestic law for manganese nodule mining pending ratification of an
international Law of the Sea treaty, was enacted in June, 1980, to provide
an interim legal framework to facilitate the continued development of deep
seabed mining in an environmentally safe and sensitive manner. Congress
declared that the purpose of the Act include an assurance that exploration
and recovery activities are to be conducted in a manner which will encourage
the conservation of the natural resources, protect the quality of the
environment, and promote the safety of life and property at sea. The Act
authorizes the Administrator of the National Oceanic and Atmospheric
Administration (NOAA) to issue licenses for exploration of the deep seabed
for manganese nodules after July 1, 1981, and to issue permits for
commercial recovery mining beginning no earlier than 1988.
The Act defines commercial recovery to include:
• Any activity engaged in at sea to recover any hard mineral
resource at a substantial rate for the primary purpose of
marketing or commercially using such resource to earn a net
profit, whether or not such net profit is actually earned,
• If such recovered hard mineral resource will be processed at
sea, such processing, and
• If the waste of such activity to recover any hard mineral
resource, or of such processing at sea, will be disposed of
at sea [PL96-283 Sec. 4(1)].
The applicant has the responsibility of submitting a recovery plan for
a permit. This recovery plan must address the proposed activities to be
carried out during the period of the permit including the methods to be used
for disposal of wastes from recovery and processing [PL96-283
Sec. 103(a)(2)(C)].
The Administrator is also responsible under the Act to implement a
marine research program to assess the environmental effects of exploration
and commercial recovery of deep seabed minerals. Accordingly, NOAA has
prepared the Five Year Marine Environmental Research Plan on Seabed Mining
29
-------
and Processing Waste. Research under the plan is aimed at providing an
assessment of environmental impacts of exploration and commercial recovery
activities including the at-sea disposal of processing wastes.
NOAA published its final rules on Deep Seabed Mining Regulations for
Exploration Licenses on September 15. 1981 (46 FR 45890). The Deep Seabed
Mining Final Technical Guidance Document (September, 1981), which provides
guidelines for meeting certain environmental requirements in the final
regulations, summarizes three categories of information to be submitted with
an application for an exploration license:
• Location and boundaries of applicant's proposed license site
• Plans for delineation of features of the exploration area
• Preliminary plans for testing and monitoring.
Additional information that should be submitted within 365 days prior
to anticipated mining system tests include:
• Selected environmental characteristics (baseline
information)
• Detailed proposed mining system test plans
• Further details on proposed test monitoring plan
• Detailed onshore processing test plans in the U.S., and
t Detailed ocean disposal test plans.
This information will be used by NOAA:
• To assess the environmental aspects of exploration-phase
activities in a license application and to prepare
site-specific environmental impact statements (EIS). The
issuance of a license or permit under this Act is deemed a
major federal action under the National Environmental Policy
Act of 1969 and an EIS must be prepared for each certified
license or permit application. NOAA will be responsible for
preparing the EIS which is required to address waste
disposal. The Final EIS will then be used as a base for
license or permit decisions.
• To develop conditions for each applicant following review of
monitoring plans, to validate whether the effects of mining
tests agree with the effects predicted in the site-specific
EIS and to detect any unforeseen adverse effects
30
-------
• To further refine estimates of the potential effects of
commercial mining, based on system testing, in order to
prepare environmentally sound regulations and guidance for
commercial recovery under a NOAA's permit
• To relate the new data to objectives of NOAA's Five Year
Research Plan on Seabed Mining and Processing Waste
Disposal.
Regulations for commercial recovery permits and associated at-sea
processing have not yet been issued by NOAA since the Deep Seabed Hard
Mineral Resources Act prohibits commercial recovery until January 1, 1988.
The commercial mining regulations will eventually explain the applicant's
responsibilities for data collection and monitoring. Current exploration
parties have indicated that they do not intend to file for commercial
recovery permits until at least 1984 (Deep Seabed Mining Report to Congress,
December, 1981).
National Environmental Policy Act
The National Environmental Policy Act (NEPA) established an
environmental review procedure designed to ensure that public officials make
decisions based on an understanding of their environmental consequences. No
specific plans or regulations on the maintenance of environmental quality
and ecosystems resulted from NEPA, however, federal managers must consider
the positive and negative environmental and socio-economic consequences of
alternative development decisions including the no-action alternative. The
Act requires that the consequences of these decisions be addressed in an
Environmental Impact Statement (EIS) from the Federal agency managing "a
major Federal action significantly affecting the quality of the human
environment."
The regulations define a major Federal action as including "actions
with effects that may be major and which are potentially subject to Federal
control and responsibility." Such actions include "new and continuing
activities including projects and programs entirely or partly financed,
regulated or approved by federal agencies, agency rules, regulations,
policies or procedures, and legislative proposals." It is anticipated that
at least one EIS will be required for the federal actions which will be
associated with the development of a deep ocean manganese nodule processing
project. The issue of waste disposal will certainly need to be addressed.
Coastal Zone Management Act
The Coastal Zone Management Act (CZMA) of 1972 affirms a national
interest in the effective management, beneficial use, protection and
development of the coastal zone. It created a program of federal grants to
help the states manage their coastal resources on shore and within the 3
mile limit or territorial seas. The Act can be viewed as a benefits program
to foster more coherent and effective action by each state to assure that
the multiple interests in the amenities and resources of their coastal zones
are balanced and protected from new developments.
31
-------
Under the CZMA, the term coastal zone means the coastal waters and the
adjacent shorelands strongly influenced by each other and in proximity to
the shorelines of the several coastal states, and includes, transitional and
intertidal areas, salt marshes, wetlands, and beaches. The zone extends in
the Great Lakes waters, to the international boundary between the U.S. and
Canada and, in other areas, seaward to the outer limit of the
U.S. territorial sea. The zone extends inland from the shorelines only to
the extent necessary to control shorelands, the uses of which have a direct
and significant influence on the coastal waters (PL94-370, 90 Stat. 1013,
July 26, 1976).
The CZMA also authorizes the Secretary of Commerce to make grants to
any coastal state for the purpose of: (1) acquiring, developing, or
operating estuarine sanctuaries, to serve as natural field laboratories in
which to study and gather data on the natural and human processes occurring
within the estuaries of the coastal zone, and (2) acquiring lands to provide
for access to public beaches and other public coastal areas of
environmental, recreational, historical, aesthetic, ecological, or cultural
value and for the preservation of islands. The sanctuaries are owned and
managed by the individual states, and are kept as undisturbed as possible so
researchers can study the naturally functioning system and also be able to
use the areas as controls against which to measure ecological changes in
other estuaries.
At present there are twelve estuarine sanctuaries in operation and
several in the planning stages. The "national program is administered by the
Estuarine Sanctuary Program Office, Office of Coastal Zone Management; a
component of the National Oceanic and Atmospheric Administration of the
Department of Commerce. Table 6 lists the twelve estuarine sanctuaries
currently in operation.
CZMA has a bearing on any proposed activity in coastal waters and
adjacent shorelands. Section 307(c) requires that after a state's coastal
zone management program has been approved "any applicant for a required
Federal license or permit to conduct an activity affecting land or water
uses in the coastal zone" must provide a certification that the proposed
activity complies with the states approved program. This "federal
consistency provision" provides states with approved programs a significant
amount of control over projects requiring federal permits.
All the states considered in this study, except for Texas, have
federally approved CZM programs currently in place (Table 7). The applicant
will be required to get the approval of the responsible agency and a
"consistency certification" for any activity affecting the coastal zone.
This gives the states and local governments a significant amount of
influence over deep seabed mining related activities.
32
-------
TABLE 6. ESTUARINE SANCTUARY NAMES AND ADDRESSES
(AS OF APRIL, 1982)
Chesapeake Bay
Dr. Sarah Taylor
Chesapeake Bay
Department Natural Resources
Tawes State Office Building
Anapolis, MD 21401
(301) 269-2786
Jobos Bay, Puerto Rico
Jose Gonzalez-Livoy
Department Natural Resources
Box 5887
Puerta de Tierra
San Juan, PR 00906
(809) 722-5501
Tijuana River, California
Sue Hansch
California Coastal Commission
631 Howard St., 4th Floor
San Francisco, CA 94105
(415) 543-8555
Sapelo Island, Georgia
Margaret Melton, Estuarine Sanctuary Coordinator
Department of Natural Resources
Coastal Resources Division
1200 Glynn Avenue
Brunswick, GA 31520
(912) 264-7218
South Slough, Oregon
Dr. Delane Munson, Manager
South Slough Estuarine Sanctuary
P.O. Box 5417
Charleston, OR 97420
(503) 888-9015
Waimanu, Hawaii
Richard Poirirer
Department of Planning and Economic Development
P.O. Box 2359
Honolulu, HI 96804
(808) 548-3047
33
-------
TABLE 6. (Continued)
Old Woman Creek, Ohio
Eugene Wright, Manager
Old Woman Creek Estuarine Sanctuary
2005 Cleveland Rd., East
Huron, OH 44839
(419) 433-4601
Dr. David Klarer, Sanctuary Biologist
Old Woman Creek Estuarine Sanctuary
2005 Cleveland Rd., East
Huron, OH 44839
(419) 433-4601
Rookery Bay, Florida
Dr. Kris W. Thoemke, Manager
Rookery Bay Estuarine Sanctuary
No. 10 Shell Island Road
Naples, FL 33942
(813) 775-8845
Apalachicola River/Bay, Florida
Mr. Woodward Mi ley II, Manager
Apalachicola River/Bay Estuarine Sanctuary
57 Market St.
Apalachicola, FL 32320
(904) 653-8063
Elkhorn Slough, California
Kenneth S. Moore, Manager
Elkhorn Slough Estuarine Sanctuary
1454 Elkhorn Road
Watsonville, CA 95076
(408) 728-0560
Padilla Bay, Washington
Mr. Milt Martin
Department of Ecology
Mail Stop PV-11
Olympia, WA 90854
(206) 549-6287
Narragansett Bay, Rhode Island
Mr. Gary Bannon, Manager
Narragansett Bay Estuarine Sanctuary
Department of Environmental Management
83 Park Street
Providence, RI 02903
(401) 277-2776
34
-------
TABLE 7. STATE AGENCIES RESPONSIBLE FOR COASTAL
ZONE MANAGEMENT PLANS
Cal i form'a
Oregon
Washington
Hawa i i
Alaska
Louisiana
Texas
California Coastal Commission
631 Howard Street, 4th Floor
San Francisco, California 94105
(415) 543-8555
Land Conservation and Development
Commission
1175 Court Street N.E.
Salem, Oregon 97310
(503) 378-4097
Department of Ecology
State of Washington
P-V-11
Olympia, Washington 98504
(206) 459-6000
Department of Planning and
Economic Development
P.O. Box 2359
Honolulu, Hawaii 96804
(808) 548-3042
Department of Community and
Regional Affairs
Pouch B, Room 213
Community Building
Juneau, Alaska 99801
(907) 465-3541
Department of Transportation
and Development
Coastal Management Section
P.O. Box 44245
Capital Station
Baton Rouge, Louisiana 70804
(504) 342-7591
No approved state plan
35
-------
Fish and Wildlife Coordination Act
The Fish and Wildlife Coordination Act was enacted for the purpose of
recognizing the vital contribution of our wildlife resources to the Nation,
the increasing public interest and signficance thereof due to the expansion
of our economy, and to provide that wildlife conservation shall receive
equal consideration and be coordinated with other features of water-resource
development programs. The Act authorizes the Secretary of the Interior to
provide assistance to, and cooperate with federal, state, local, public, or
private agencies and organizations in the development, protection, rearing,
and stocking of all species of wildlife, resources, and their habitats, in
or effecting controlling losses from disease or other causes and in
minimizing damages. According to Section 5 of the Act, the Secretary of the
Interior, through the Fish and Wildlife Service and the Bureau of Mines, is
authorized to make any investigations as deemed necessary to determine the
effects of domestic sewage, mine, petroleum, and industiral wastes, and
other polluting substances and report the findings to Congress. For any
waste disposal in the oceans, consultation with the Fish and Wildlife
Service of the Department of the Interior and the National Marine Fisheries
Service of the National Oceanic and Atmospheric Administration is necessary
to ensure compliance with their guidelines and policies for alleviating
dangerous and undesirable effects of the proposed action.
Endangered Species Act
The Endangered Species Act of 1973 was enacted to protect and conserve
endangered and threatened species and their critical habitats. The Act
vests in the Secretary of the Interior and the Secretary of Commerce broad
regulatory authority to list species determined to be end-angered or
threatened, and to designate the critical habitats of such species. It also
imposes an affirmative duty on federal agencies to promote the conservation
of endangered or threatened species of fish, wildlife, or plants. The
Secretary may enter into a cooperative agreement with any state which
establishes and maintains an adequate and active program for the
conservation of endangered or threatened species of fish, wildlife, or
plants.
Prior to submitting any permit associated with ocean disposal
activities, the applicant will need to ensure that the activities to be
authorized will not jeopardize the continued existence of any listed species
or destroy or modify a designated critical habitat of such species.
However, if activities related to the construction of a marine terminal,
offshore mooring point, pipelines, or actual disposal of wastes will have
the likelihood to have effects on endangered species or critical habitats,
the prospects of obtaining a permit will be greatly reduced. Consideration
of endangered or threatened species and critical habitats warrants strict
attention in the early project planning stages. Coordination with the
Department of Interior, Department of Commerce (National Oceanic and
Atmospheric Administration, National Marine Fisheries Service) and
appropriate state agencies will help avoid lengthy project delays regarding
threatened or endangered species.
36
-------
Marin-e Mammal Protection Act
The Marine Mammal Protection Act of 1972 was enacted to protect marine
mammals, establish a Marine Mammal Commission, and to maintain marine
mammal's significance as a functioning element of the marine ecosystem. The
Secretary of Commerce is given responsibility for whales, porpoises, seals,
and sea lions, and the Secretary of Interior is given responsibility for all
other marine mammals. Any activities which result in the indirect "taking"
of marine mammals requires that an "incidental taking" permit be obtained
from the National Marine Fisheries Service under the authority of _the
Secretary of Commerce. Any interference with marine mammals or any actions
having an adverse effect on their habitat resulting from disposal operations
may raise the question of whether they constitute an "incidental taking"
which requires a permit. Consultation with local National Marine Fisheries
Service representatives and appropriate state agencies concerning the
proposed action should take place early to avoid lengthy delays due to
marine mammal conservation and protection programs.
National Historic Preservation Act
The National Historic Preservation Act of 1966 established a program
for the preservation of additional historic properties throughout the
Nation. The Act authorizes the Secretary of the Interior to maintain a
natural register of districts, sites, buildings, and objects significant in
American history, architecture, archeology and culture. The Act imposes a
duty on federal licensing agencies to consider the effect on historic sites
of the proposed activity. If there is any effect on historic or
archaeological sites, all activities must be reviewed and commented on by
the Advisory Council on Historic Preservation. If a determination warrants
further action, the Preservation of Historical and Archaeological Data Act
of 1974 authorizes the Secretary of the Interior to take any action deemed
necessary to recover and preserve significant historical or archaeological
data threatened by activities at such sites. This is a sensitive issue and
may cause extensive delays and a possible ending of the proposed activity if
it is not considered early in the site selection process for waste disposal.
CONCLUSIONS
Federal environmental legislation governing ocean disposal of manganese
nodule processing wastes consists primarily of two acts: the Clean Water
Act (CWA) which regulates ocean discharges, and the Marine Protection,
Research, and Sanctuaries Act (MPRSA) which regulates ocean dumping. It
appears that the ocean need not be excluded from waste management strategies
for the disposal of manganese nodule processing wastes based upon close
review of both statutes and their existing regulations.
37
-------
Characterization studies of manganese nodule processing wastes indicate
that the wastes can meet the environmental criteria and permit requirements
for "strictly regulated dumping" and "trace constituents and other limited
materials" for ocean dumping, in addition to meeting some of the stringent
state water quality standards for point source discharges.
38
-------
3. OCEAN DISPOSAL TECHNOLOGIES
This chapter discusses present and potential ocean disposal technology
and the resulting fate of material. Because the method of disposal can
significantly influence the fate of material, each method is considered
separately. The application to manganese nodule processing rejects of three
basic methods of ocean disposal are considered; ocean dumping, pump out of
ships or barges at sea, and ocean outfalls. Each disposal method discussion
is followed by a brief discussion of the fate of solids disposed of by that
method. In the case of ocean dumping from a barge, a simplified procedure
has been developed which can be used to estimate solids transport and
dispersion. A detailed technical discussion of the procedures and their
limitations are described in Appendix B. These procedures are used in
Chapter 6 to estimate the fate of waste materials discharged to
representative disposal areas. These estimates are very approximate, and
should be used only to qualitatively differentiate dumping strategies and
locations. Many of the technical difficulties are discussed in Appendix B.
DISPOSAL TECHNOLOGY
Conventional technology for the disposal of wastes in the ocean employs
bottom dump barges, split hull barges,'ocean outfalls, and specialized
sludge dumping ships. Much of this technology is adaptable to the disposal
of manganese nodule processing wastes.
Ocean Dumping
Approximately 90 percent of the waste tonnage dumped at sea in 1979 was
dredged material dumped by barge or hopper dredge. Both types of vessels
release their load through the bottom of the vessel. Bottom dump barges and
hopper dredges are partitioned into a number of compartments, each fitted
with a set of bottom doors. The bottom door system usually consists of a
pair of doors (port and starboard) running the length of each compartment
and hinged along the outboard edges so that they open downward.
The barge is towed to the dump site by a tugboat. When the barge is in
position to dump, the bargeman releases each set of doors. He first
releases the hopper at either the bow or stern and then releases the hopper
at the opposite end. The alternating pattern is continued until the last
hopper is discharged in the midships area. This procedure prevents the
vessel from going far out of trim during a dumping cycle. The total
unloading time for a manually operated barge consists of the time to release
and dump one hopper and to walk back and forth over the deck route.
According to Johanson et al. (1976), a 3,060 m3 (4,000yd3) barge releases
and dumps a single hopper in 1 min with a time of 6 min required to empty
the entire barge.
39
-------
The bottom dump barge is being replaced by the split-hull or clamshell
barge. Although still in use, a limited survey of barge manufacturers
revealed that bottom dump barges are no longer being manufactured in the
United States. New barges specifically designed for ocean disposal of
manganese nodule processing waste would probably be of the split-hull
design. Split or clamshell barges are designed with hulls that hinge open
to release the load through the bottom. Figure 3 shows a 2,294 m^ (3,000
yd3) split-hull barge in open and closed configuration.
The split-hull design eliminates practically all of the manual effort,
and it empties the entire load in one operation. One lever controls the
hydraulic piston which rotates the hull open to release the load over the
entire hopper length. When opened, the hull is held open by buoyant forces.
When closed, hydrostatic pressure acts to keep the hull closed.
The split-hull dumping sequence is illustrated in Figure 4. The time
required to empty is only a few seconds. The opening of the barge can be
stopped at any position to regulate the rate of material discharge.
The split-hull barge is more versatile than the conventional
bottom-dump. If maximum dispersion of the waste is desired, the hull
opening can be controlled. The split-hull can be opened quickly (in seconds
as opposed to 6 min) to achieve maximum concentration of the waste.
The barges illustrated in Figures 3 and 4 are Manitowoc "Hydro-Dump"
barges. Standard sizes range from 153 m3 (200 yd3) to 3,060 m3 (4,000 yd3).
Specifications for the largest standard size are presented below:
Size 3,060 m3 4,000 yd3
Approximate capacity 4,900 metric tons 5,400 tons
Length overall 72 m 236 ft
Length beam 16.2 m 53 ft
Depth midship 6.4 m 21 ft
Loaded draft 6.0 m 20 ft
Light draft (closed) 1.2 m 4 ft
Barges of greater capacity could be designed and built. The largest barges
currently being built in the United States are designed for carrying liquids
and exceed 55,000 dwt.
A single manganese nodule processing plant is estimated to generate
from approximately 2.7 to 3.5 million metric tons per year of
hydrometallurgical rejects. This represents approximately 550 to 700 dumps
from the largest standard-sized barge (4,900 metric tons). Assuming 300
working days per year, dumps would occur at a rate of from 1.8 to 2.4 dumps
per day.
40
-------
Figure 3. A split-hull bottom dump barge in open and
closed configuration.
41
-------
Figure 4. The dumping sequence of a split-hull barge.
42
-------
FATE OF OCEAN DUMPED MATERIAL
Barge Dumping
Disposal of waste material into the ocean using barges results in dumps
of relatively short duration ranging from a few seconds for a split hull
barge to several minutes for a hopper barge. The discussions which follow
consider only instantaneous dumps in water deep enough for the dump material
to be considered as a hemispherical cloud. A schematic representation of an
instantaneous dump is presented in Figure 5. Dumps in relatively shallow
water where the duration of release is comparable to the time required for
the cloud to impact the bottom are described elsewhere (see Barnard 1978).
If the water depth is not sufficiently great, the plume of waste material
impacts the bottom before equilibrium of the plume and the surrounding
seawater is reached and surges along the bottom.
The physical processes which govern the behavior of the dumped material
in deep water are divided into 3 phases: the convective descent, the
dynamic collapse, and the passive diffusion. The division of the processes
into these three phases is found in the modeling efforts of Koh and Chang
(1973) and Brandsma and Divoky (1976), and is schematically illustrated in
Figure 6. The plume can be represented as a hemispherical cloud. During
the convective descent, the cloud falls at a rate determined primarily by
its total mass and size and entrains ambient water. The sizes of the
particles which compose the solid portion of the cloud are of secondary
importance during this phase. The downward force on the cloud is its
negative buoyancy, which decreases as it entrains ambient water. The
resisting forces are primarily due to drag. The dynamic collapse phase
occurs when the cloud has entrained sufficent water to reach the point where
density of the cloud equals that of the surrounding water. Due to its
downward momentum, the cloud continues to fall past the level of neutral
buoyancy entraining water which results in the cloud becoming positively
buoyant. The successive buoyancy changes produce a rise and fall
oscillation about the position of neutral buoyancy. These oscillations
cause the cloud to flatten and behave more and more as individual particles.
The passive diffusion phase begins at this point. The particles are
advected by local currents and dispersed laterally by horizontal diffusion.
The particles settle at a rate determined by their fall velocity and any
vertical currents. If the particle size is small enough, vertical diffusion
will alter the particles' rate of descent. These motions continue until the
particle settles on the sea floor.
There are basically two types of fate for material discharged by
instantaneous dump. The falling cloud can be trapped at some depth in the
water column, and is eventally transported and diffused by horizontal
currents while the particles fall at their respective fall velocities. The
other possibility is that the cloud will impact the bottom. The resulting
surge will spread out radially, and eventually will be transported
horizontally by the ambient currents until the particles settle on the
seafloor.
43
-------
REFERENCE: Pequegnat et al, 1931
VERY LCW DENSITY MATERIAL
LOW-DEHSinr MATERIAL ON Tt«RMO-PYC WCLI
DISPOSAL SITE BOUNDARY
Figure 5. Schematic representation of ocean dumping.
-------
CONVECTIVE DESCENT
ENCOUNTER
NEUTRAL
BOUYANCY
COLLAPSE
PASSIVE
DIFFUSION
DIFFUSIVE SPREADING
GREATER THAN
DYNAMIC SPREADING
Figure 6. Idealized discharge from moving vessel
-------
A method to determine the area as well as the average concentrations,
or height (if the cloud impacts the bottom) at 4 hours time is described in
Appendix B. The method is very approximate and is useful only to give rough
qualitative comparisons between alternative disposal procedures. A
discussion of the technical difficulties with the method is contained in
Appendix B. Several figures are presented below which summarize the
predictions. Also discussed is an example computation. Figure 7 shows the
horizontal area covered by an instantaneously dumped cloud after 4 hours as
a function of trapping level and initial dump volume. Figure 8 shows the
dilution achieved after 4 hours. For initial cloud densities equal 1.4
g/cm^ and 2.0 g/cnr Figures 9 and 10 give the thickness of the sediment
layer if the solids suspended in the dump cloud were to fall uniformly in
the horizontal cloud area after 4 hours time.
As an example suppose 1,000 m^ having bulk density equal 1.4 g/cm^ is
discharged in oceanic waters having depth 250 m (820 ft) and constant
normalized density gradient e= Ixl05/m (3.1xlO"°/ft). The equation for the
trapping level draax contained in Appendix B shows that the dump cloud
reaches its equilibrium level (trapping level) 212 m (696 ft) below the
surface. Using Figure 7, the area equals 0.034 km2 and using Figure 8, the
dilution is 1,300. The average material thickness, using Figure 9, is 5 mm.
If the solid material in the cloud had a density equal 3.4 g/orr and no
particles have diameters greater than 121 urn, then the largest particles
will fall no more than 1.4 m (4.6 ft) after the dump cloud reaches the
trapping level.
Surface and Subsurface Dispersal
An alternative to dumping processing waste from a barge is to pump the
material out, discharging the slurry to the surface or to greater depth. By
pumping out the barge, bottom dump capability is no longer needed. Existing
vessels or barges, such as ore carriers, could be modified for slurry pump
out capability to dispose of the manganese nodule processing waste. The
transport ships used to convey manganese nodules from the mining site to the
processing plant could also be designed to discharge the waste at sea.
The maximum possible dispersion of the waste could be achieved by
pumping the waste slurry into the wake of a moving barge or ship as it
traverses a course of many miles. This technique is currently used to
dispose of acid wastes at the New York Bight acid waste dump site (NOAA
1975). The disadvantage of this method is that the waste achieves the
maximum residence time in the euphotic zone where it may impact
phytoplankton and zooplankton populations.
This problem can be avoided by discharging the slurry through a pipe
extending downward below the euphotic zone to depths of 50 to 100 m (160 to
320 ft). This concept, referred to as shunting, is used in the offshore oil
and gas industry to minimize dispersion of drilling muds and cuttings.
U.S. Army Corp of Engineers has also evaluated this concept for accurate
placement of dredged material into offshore borrow pits (Johanson et al..
1976).
46
-------
100
50
10
.5
LU
EC
.05
.01
.005
- V=5000m3
V=4000m3
V= initial volume of dump
•V=3000m3
- V= 2000m3
-V=1000m3
-V=500m3
-V=200m3
I I I I ! I I I I I I I I I I I I I I I I I I I I I
10
5O TOO 500 1000
WATER DEPTH (M)
5000 10000
Figure 7. Horizontal area covered by instantaneous dump
cloud 4 hours after dumping as a function of
trapping level.
47
-------
1000
500 -
I I I I I I Ml
v= initial volume of dump
V=200m3
V=500m3
V = 1000m3
V= 2000m3
V= 3000m3
V= 4000m3
V= 5000m3
I ! I I I I II
I II
50O 1000
5000 10000
WATER DEPTH (M)
Figure 8. Dilution achieved by instantaneous dump cloud
4 hours after dumping as a function of trapping
level.
-------
1000
500
100
50
10
S 5
(A
V)
UJ
z
*
u
I
.5
.05
.01
10
V = 5000m3
= 4000m3
= 3000m3
= 2000m3
= 1000m3
V=500m3
= 200m3
V = initial volume of dump —
I I 1 I I I 111
I I
50 100
5OO 1000
5000 10OOO
WATER DEPTH (M)
Figure 9. Thickness of sediment layer if the solids
suspended in the dump cloud were to fall
uniformly in the horizontal cloud area after ,
4 hours time (initial cloud density = I.4 gm/cm )
49
-------
1OOO
500
I I I I I I I 11 1 I I I I I I 11
100
50
to
(A
O
X
10
S 5
.5
.05
.01
10
= 500Om3
V = 40OOm3
V=3OOOm3
V= 2000m3
V = 1000m3
= 500m3
V = 2OOm3
V= initial volume of dump _
50
10O
500 1000
5000 10OOO
WATER DEPTH (M)
Figure 10. Thickness of sediment layer if the solids sus-
pended in the dump cloud were to fall uniformly
in the horizontal cloud area after-4 hours time
(initial cloud density = 2.0 gm/cm ).
50
-------
Other examples of barge pump-out capability exist. These include self
loading and unloading, bulk and liquid barges in the 7,000 to 20,000 dwt
range and pump-out barges commonly used in Europe to unload and pump ashore
dredged material from transport barges (Johanson et a!., 1976).
An additional concept which can be added to the pump down technique is
the use of a diffuser plate at the end of the discharge pipe. The purpose
of the diffuser, developed by the U.S. Army Corps of Engineers (Barnard
1978), is to minimize the momentum and energy of the discharge as it exits
the pipe. The diffuser, shown in Figure 11, thus reduces the dispersion of
the slurry. The material will basically fall out the diffuser rather than
act as a turbulent jet.
The diffuser concept is most applicable to pump down in relatively
shallow water, approximately 60 m (200 ft). The diffuser could be placed on
the bottom, if flexible pipe can be used, or maintained at a safe distance
above the bottom at the end of a rigid pipe string. The material creates
clouds around the diffuser from which particles would settle individually.
The buoyant liquid fraction could however rise to the surface or to some
level of neutral buoyancy.
The farfield behavior of material continuously discharged into the sea
from a pipe aboard a ship is similar to the passive diffusion stage of
dumped material. The nearfield behavior is different in that the initial
flow is similar to a jet and not a single cloud. The flow of a buoyant jet
into an ambient fluid is well known (Koh and Brooks 1975) and a number of
computer models exist, which predict the level of neutral buoyancy of the
resulting plume (see Teeter and Baumgartner 1979 for example).
Particle-laden jets appear to entrain water less efficiently (Ditmars and
McCarthy 1975) and, hence, the level of neutral buoyancy for a
particle-laden jet will be greater than that of a negatively-buoyant jet.
In most present ship discharges of this type, the end of the pipe is close
to the water surface. Thus, prediction of the trapping level depends on the
wake of the ship as well as location and orientation of the pipe (see
Brandsma and Wu 1980). Regardless of the complexities of the flow near the
exit pipe, the jet plume reaches equilibrium quickly. From a distance, the
resulting cloud looks like a continuously generated pulse source. This can
be approximated by an exponential function (Lavelle and Oztergut 1981).
Advective transport in the open ocean is primarily horizontal. Horizontal
currents commonly have speeds measured in cm/sec. Since 1 cm/sec = 0.864
km/day, a waste field would likely be advected a number of km/day. Vertical
advective transport is ignored, although vertical currents during periods of
upwelling may influence the fall velocity of very small diameter particles.
Predictions of the convective descent phase of a jet depend on enough
parameters so that a method as simple as the method for instantaneous dumps
is not possible. In Appendix B, the farfield model of Brooks' is used to
obtain some passive dispersion results.
51
-------
MOUNTING FLANGE
SLURRY FLOW
CONICAL DIFFUSER
SECTION
GASVENT
GAS SHROUD
ABRASION PLATE
IMPINGEMENT PLATE
TURNING & RADIAL
DIFFUSER SECTION
SUPPORT STRUT
RADIAL DISCHARGE
/// 77T
BOTTOM SEDIMENT
7/r
//r
REFERENCE: Barnard 1978
Figure 11. Submerged diffuser.
52
-------
Marine Outfalls
Occasionally outfalls are used to dispose of waste material in slurry
form. There are basically two possible strategies for discharging wastes
through an outfall into marine waters. One is to make the discharge mixture
have a specific gravity greater than seawater, while the other is to make
the mixture have a specific gravity less than seawater. These possibilities
are schematically shown in Figure 12. Heavier-than-water slurries must be
discharged on a sloping seabed to ensure that the settled material moves
downslope away from the outfall and does not accumulate at the outfall site.
This method has been used in a number of locations. The Hyperion sludge
outfall in Santa Monica Bay discharges municipal waste sludge at the head of
a submarine canyon. An outfall in Rupert Inlet on Vancouver Island, B.C.,
discharges mining waste into a fjord (Evans et al., 1979). Other examples
are described in Chapter 5 of this report. Properly designed, this method
offers a number of advantages. The movement of the material is independent
of the water column density structure. Impacts are restricted to the
benthic environment. Only bottom currents affect the motion of the
material. Problems can develop however. At Hyperion, internal waves can
cause surges in the submarine canyon which can transport material from the
outfall diffuser upward and onto the shelf. Deep water upwelling at a sill
in Rupert Inlet occasionally transports solids up into the water column. In
both examples, the diffuser is in relatively deep water [on the order of 61
m (200 ft) or more]. Hence, oscillatory bottom currents due to wind waves
are not likely to resuspend settled solids unless the waves are high and
have long periods.
Some care must be used in the design of the outfall. If the flow
behaves as a turbidity current, then gravity causes the current to seek the
greatest possible depths. Energy losses due to friction can stop the
current on a mild slope. However, sufficient mounding will induce slumping
and further movement. If the initial discharge velocities are too high, a
portion of the turbidity current may separate from the seabed and form a
cloud in the water column. Once formed, this cloud would be advected and
dispersed by the ambient ocean currents. This situation occurs in Alice
Arm, British Columbia, where mine tailings are discharged near the head of a
fjord (Burling et al., 1981). Burling et al. (1981) suggests that the cloud
may be caused by a hydraulic jump occuring in a supercritical discharge.
The mechanics of separation do not appear to be understood at present.
Clouds may also separate from the turbidity current due to the positive
buoyancy of the fluid in the slurry (usually fresh water) with respect to
the ambient seawater. Thus, it appears that flows which initially have as
small a water content as possible and discharged slowly may avoid the
problem of cloud formations. Physical simulation of slurry jet discharges
are needed to develop an understanding of their behavior.
The procedure of discharging mining wastes in mixtures which have
specific gravities less than that of saltwater appears to be impractical and
has evidently never been attempted in the U.S. The advantage of such a
scheme would be that the discharge plume is trapped in the water column and
advected away from the diffuser site by the ambient currents. Aside from
the high turbidity levels which would occur near the trapping level of the
53
-------
A.
• WATER SURFACE
OUTFALL PIPE-
B.
• WATER SURFACE
AMBIENT
• CURRENT
DIRECTION
OUTFALL
Figure 12. A) Negatively buoyant discharge on a sloping
bottom.
B) Positively buoyant discharge on a horizontal
bottom.
54
-------
wastefield, the principal problem is the amount of fresh water required to
reduce the specific gravity of the slurry to less than that of seawater.
ADDITIONAL CONCEPTS
Block Formation
As previously noted, the particle size of dumped rejects has a very
important influence on their eventual fate. Very small particles, in the
micrometer range, settle very slowly and can be widely dispersed. Particles
in the millimeter size range settle relatively quickly. If the
concentration of the waste within a small area of the seabed is desired,
this could be done by artifically increasing the particle size. For
example, rejects formed into brick-size blocks would sink very rapidly and
remain in distinct piles on the bottom.
Other advantages accrue in addition to rapid sinking. The particle
surface area of the blocks in contact with seawater is extremely small
compared to unmodified rejects. The opportunity for potentially toxic
constituents to exchange from the reject solids to the ambient seawater is
therefore greatly reduced. The second potential advantage is that rejects
in large blocks could be placed as an artificial reef. Such reefs could
actually enhance biological communities on the continental shelf.
The idea of forming waste material into blocks and forming reefs has
been investigated by Woodhead et al. (1979). Experimental reefs were formed
of fly ash and scrubber sludge from coal-fired.power plants at a site
located approximately 1.3 km (2 mi) south of Fire Island, New York.
Woodhead et al. (1979) found that the blocks of power plant waste retained
their physical integrity in seawater and did not appreciably erode or
dissolve. Extensive tests showed no adverse effects to marine organisms.
A final advantage may exist in the ability to recover the disposed of
rejects. Rejects generated by the "three-metal" processes still contain
potentially valuable quantities of manganese. Blocks deposited in shallow
water [less than 90'm (200 ft)] may be much more feasible to recover than a
deposit of untreated rejects.
The technical and economic feasibility of forming blocks with rejects
is not known. Substantial work would be necessary to determine the
feasibility of this alternative.
Capping
Once a deposit of manganese nodule rejects is in place on the seabed it
may be possible to cover (or cap) the deposit with uncontaminated sediments.
This would prevent long term impacts of the deposit. For example, if it was
found that benthic organisms were concentrating undesirable compounds from
the reject deposit, a cap of clean sand could be dumped on top of the
rejects to isolate the rejects from the organisms. This concept is
currently being evaluated by the Corps of Engineers, New York District
(Suszkowski 1982).
55
-------
Approximately 764,500 m3 (1,000,000 yd3) of contaminated dredged
material were deposited in approximately 21 m (70 ft) of water at the New
York Bight mud dump site. Approximately 1,530,000 mj (2,000,000yd3) of
clean sand was then deposited to form a 0.6 m- (2 ft-) thick cap over the
contaminated sediment (Suszkowski 1982). The New York District is currently
performing studies to determine the effectiveness of the capping technique.
Capping may be an effective technique to isolate manganese nodule
processing rejects, if required, in shallow water [less than approximately
300m (1,000 ft)]. The ability to control the placement of dumped, or
pumped down, material decreases as water depth increases. The amount of
cover material required to cover a reject deposit in deep water may prove
prohibitive.
The capping technique may also prove useful in reverse. Manganese
nodule processing rejects may prove to be suitable as a cover material. In
this case, rejects could be used to bury and isolate potentially harmful
wastes such as highly contaminated dredged material or low-level radioactive
wastes.
56
-------
4. CURRENT OCEAN DISPOSAL ACTIVITY
Untreated municipal wastewater was probably the first material to be
discharged to the ocean in any large quantities. The earliest type of
material dumped in the ocean was dredged material from harbor entrance
channels. Regulation of this form of dumping began in 1888, primarily
because of concerns of possible interference with navigation. New York City
began dumping sewage sludge at a s.ite 19 km (12 mi) outside the harbor in
the 1920s. Ocean dumping of industrial wastes in significant quantities
began on the Pacific and Atlantic Coasts in the 1940s and on the Gulf Coast
in the 1950s. As with dredged material, where regulations existed
concerning municipal sludge and industrial wastes, the primary concern was
not over environmental impacts, but with constraints on navigation (Wastler
1981).
Since World War II, the U.S. government has disposed of obsolete or
unserviceable equipment, ammunition, rocket fuels, and other unsalvageable
war materials in deep waters off the U.S. coasts. Generally the material is
transported by barges and ships and dumped over the side. However, within
the last 20 years, gutted World War II cargo ships are loaded with material-
and sunk in water with depths over 1,800 m (6,000 ft) (Wastler 1981).
The Atomic Energy Commission disposed of limited quantities of packaged
radioactive waste materials between 1946 and 1967 (Wastler 1981). In most
cases the material was packaged in 55-gal steel drums. Four principal
radioactive waste disposal sites were utilized. Two sites were in the
Pacific Ocean near the Farallon Islands, with depths of about 914 m (3,000
ft) and 1,700 m (5,600 ft). Two sites in the Atlantic Ocean had depths of
2,800 m (9,200 ft) and 3,800 m (12,500 ft), and were located 193 km (120 mi)
and 322 km (200 mi) off the Maryland-Delaware coasts, respectively (EPA
1979).
Nearly 300 ocean dump sites have been used historically, mostly for
dredged materials. Public interest in the effects of materials disposed of
at these sites was aroused in 1969 - 1970 due to incidents involving the
disposal of chemical warfare agents. Simultaneously, studies completed by
several universities and NOAA identified potentially adverse effects of
industrial waste and sewage sludge disposal in the New York Bight. The
Council on Environmental Quality reported in 1970 to the President and
identified poorly regulated waste disposal as a potential marine
environmental danger (EPA 1980b).
Subsequent chapters of this report evaluate the potential impacts of
reject disposal at generalized locations (i.e., mid shelf, shelf edge, and
deep ocean) within western Gulf of Mexico, southern California, Pacific
Northwest, and Hawaii regions. It should be noted that interim and final
designated disposal sites exist nearshore in each of these regions for
disposal of dredged material (Table 9). These sites are not specifically
addressed in this report. They are theoretically, however, potential
disposal sites for manganese nodule processing rejects. The possibility of
using these sites to dispose of materials other than dredged material is not
known.
57
-------
WASTE QUANTITIES AND DISPOSAL SITES
Ocean Dumping
Approval of ocean dumping sites is the responsibility of EPA.
Presently, 142 disposal sites have been designated - 12 for municipal and
industrial wastes and 130 for dredged materials (Smith 1981). All sites
except the incineration site in the Gulf of Mexico are designated as interim
approved, based primarily on historical use. The Gulf of Mexico at sea
incineration site was given final designation in 1976, for a 5-yr period of
use. Final designation was given to an incineration at sea site in the
Pacific Ocean near Johnston Island for disposal of the herbicide Agent
Orange; however, the period of use was for only 3 months in 1977.
In 1979, all ocean dumping of materials other than dredged material
occurred at sites in the Atlantic Ocean, with the exception of a single site
in the Pacific Ocean where 998 tons of abandoned vehicles and equipment were
dumped near Kwajalein Island under a special permit. Table 8 shows the
location, principal waste types, and status of ocean disposal sites. The
two sites in the Pacific Ocean are located near Johnston and Kwajalein
Islands. The sites which have received the greatest use include the sewage
sludge sites in the New York Bight and off Maryland (the Philadelphia sludger,
site) and the industrial waste sites off New York (deepwater dumpsite 106
and the New York/New Jersey acid waste dumpsite), Puerto Rico (near
Arecibo), and on the Gulf Coast (the Galveston site and Mississippi River
site). The Mississippi River, Galveston, New York/New Jersey acid waste,
and the Philadelphia sludge sites have been abandoned (Anderson et al.,
1979). The only sites still in use for municipal and industrial wastes are
the Puerto Rico chemical waste site, deepwater dumpsite 106, the New York
Bight, and the Gulf incineration site (NOAA 1980; Anderson et al., 1979).
Dumping at these remaining sites is scheduled to decrease. Of the four
industrial permittees at the deepwater dumpsite 106, three are scheduled to
cease ocean disposal by the end of 1981. The remaining permittee, Du
Pont-Grasselli, will be permitted to continue because the waste complies
with current EPA criteria and because no viable land-based alternative is
available (EPA 1980b). Dumping of municipal sewage sludge at deepwater
dumpsite 106 may also be curtailed, depending on capacity and health
considerations at the New York Bight site.
The 130 dredged material disposal sites granted interim status by EPA
are scattered along the Atlantic, Gulf, and Pacific coasts. Efforts
currently underway are developing environmental impact statements to enable
permanent designation of 50 ocean disposal sites (COE 1980). These 50 sites
were the only sites receiving dredged material in 1979. Table 9 indicates
the latitude and longitude of these sites. The most active site is the
Southwest Pass dredged material disposal site located in the Gulf of Mexico.
Other large-scale active disposal sites are the Mud Dump site in the New
York District and sites at the mouth of the Columbia River in the Portland
District (COE 1980). Although four coastal districts (Seattle, Norfolk,
Baltimore, and Philadelphia) reported no dredged material ocean disposal
activities in 1979, dredged material dumping is expected to continue
utilization of ocean disposal sites in the future.
58
-------
TABLE 8. OCEAN DUMPING SITES FOR MUNICIPAL AND INDUSTRIAL WASTES
Site
Location
Primary Use
Status (as of July 1982)
en
1. Region II Sludge
(NY Sludge Site)
2. Region II Industrial
Wastes Site
(Galveston Site)
3. Region II Industrial
Wastes Site ("106" Site)
4. Region III Sludge Site
(Philadelphia Sludge
Site)
5. Region III Acid Site
(DuPont Site)
6. Region II Acid Site
(NY Acid Site)
7. Region VI Industrial
Wastes Site (Mississippi
River Site)
8. Region I Industrial
Wastes Site
9. Region II Industrial
Wastes Site (Puerto
Rico Site)
10. Region II Construction
Debris Site (NY "Cellar
Dirt" Site)
40°22'30"N to 40°25'00"N
73°41'30"W to 73045'00"W
27°12'00"N to 27°28'00"W
94°28'00"N to 94°44'00"W
38°40'00"N to 39°00'00"N
72°00'00"W to 72°30'00"W
38020'00"N to 38°25'00"N
74°10'00"W to 74°20'00"W
38°30'00"N to 38°35'00"N
74°15'00"W to 74025'00"W
40°16'00"N to 40°20'00"N
73°36'00"W to 73°40'00"W
28°00'00"N to 28°10'00"N
89°15'00"W to 89°30'00"W
43022'30"N to 40°25'00"N
73°4r30"W to 73°45'00"W
19°10'00"N to 19°20'00"N
66035'00"N to 66°50'00"W
40°23'00"N, 73°49'00"W
0.6 nautical mile radius
Municipal sewage
sludge
Still in use
Industrial wastes Interim approved (never used)
Industrial wastes Interim approved
Municipal sewage Terminated December 1980
sludge
Acid wastes
Acid wastes
Terminated December 1980
Final approved
Industrial wastes Terminated
Industrial wastes Terminated
Industrial wastes Terminated September 1981
Construction or Proposed for final approval
demolition debris
-------
TABLE 8. (Continued)
11. Region VI Gulf of
Mexico Ocean
Incineration Site
12. Region II Wrecked
Vessel Dump Site
(NY "Wreck" Site)
13. Region I Industrial
Wastes
14. Region IV Industrial
Waste Site
15. Region II Wood
Incineration Site
16. Headquarters Herbicide
Orange Incineration Site
17. Region IX
Kwajalein Ocean
Dumping Site
18. Region II Alternate
Sewage Sludge Site
19. Region IX
San Nicholas Site
27°06'12"N, 93°24'15"W
26°32'24"N5 93°15'30"W
26019'00"N, 93°56'00"W
26°52'40"N, 94°04'40"W
40°10'00"N, 73°42'00"W
0.5 nautical mile radius
42°25'42"N, 70°35'00"W
1 nautical mile radius
31°46'00"N, 80°30'00"W
31°47'06"N, 80°29'00"W
31°48'00"N, 80°30'30"W
31°46'30"M, 80°32'00"W
40000'00"N to 40°04'20"N
73°4rOO"W to 73038'10"W
15°45'N to 17°45'N
171°30'W to 173°30'W
08°47'N, 167°36'W
40010'30"N to 40°13'30"N
72°40'30"W to 72°43'30"W
San Nicholas Basin
At-sea incineration Final approved
Wrecks
Terminated
Industrial wastes Terminated
Industrial wastes Terminated (never used)
Incineration of
wood
Incineration of
herbicide orange
Waste material from
Kwajalein Missile
Range
Sewage sludge
Drilling fluids
Interim approved
Terminated
Terminated
Interim approval,
not used yet
Final approval
(still in use)
Sources: EPA (1977), Ramsey (1982), and 40 CFR Part 228.12.
-------
TABLE 9. DREDGED MATERIAL OCEAN DISPOSAL SITE LOCATIONS AND
DISPOSED YARDAGES FOR CALENDAR YEAR 1979
NORTH LATITUDE WEST LONGITUDE
in degrees(°) In degrees(')
ninutes(') and minutes(') and
# secondsC1) seconds(")
1. 43 34 06 70 01 48
2. 42 25 54 70 3" 55
3. 40 21 "8 73 51 28
"4. 40 32 30 73 54 00
5. «0 35 06 73 "7 06
6. 33 50 00 78 02 30
7. 34 40 00 76 141 00
8. 33 n 13 79 07 20
9. 32 05 "0 80 35 30
10. 32 38 06 79 "9 21
11. 31 57 55 80 «6 58
12. 31 02 35 81 17 "0
13. 27 35 "9 82 51 75
It. 27 35 32 82 5t 42
15. 27 35 "1 82 52 36
16. 27 35 58 82 "9 39
17. 27 09 53 80 09 30
18. 26 46 00 79 58 55
19. 30 "2 00 81 19 05
20. 30 21 30 81 18 3"
Atlantic Ocean Subtotal 20 sites
1. 30 1 1 18 88 58 2"
2. 30 11 54 88 33 06
3. 30 10 00 88 07 42
"4. 29 28 53 89 08 08
5. 28 54 24 89 26 03
6. 29 15 00 91 27 00
7. 29 it 30 93 20 40
8. 29 27 00 93 44 00
9. 29 29 00 93 "5 00
10. 29 32 00 93 "47 00
n. 29 36 00 93 49 00
12. 29 17 00 9t 38 00
13. 28 5t 00 95 17 00
14. 28 24 00 95 19 00
15. 26 3"4 17 97 16 12
16. 26 01 00 97 06 00
Gulf of Mexico Subtotal "6 sites
1. 37 "45 00 122 35 00
2. 40 145 nil 124 15 142
3. 33 37 06 118 17 24
it. 112 02 00 121 16 00
5. 1.3 21 59 12"4 22 15
6. "43 22 44 12K 22 18
7. 142 07 54 121 27 04
8. 46 15 00 12" 06 00
9. 46 114 00 12t 11 00
10. 44 01 32 124 07 37
11. 143 UO 00 12M 14 18
12. 114 36 03 12<4 06 OH
13. 6K 30 140 165 25 52
114. 21 H4 30 157 54 30
Pacific Ocean Subtotal 11 sites
TOTAL (All Sections) 50 sites
Source: COE 1980.
SITE NAME/DISTBICT LOCATION
ATLANTIC OCEAN SECTION
Portland/New England Division, ME
Marblehead/New England Division, ME
Mud Dump/New York, NY
Roc'kaway/New York, NY
East Rockaway/Nev York, NY
Wilmington/Wilmington, NC
Morehead City/Wilmington, NC
Georgetown/Charleston, SC
Port Royal/Charleston, SC
Charleston/Charleston, SC
Savannah/Savannah, CA
Brunswick/Savannah, CA
Tampa/Jacksonville, FL
Tampa/Jacksonville, FL
Tampa/Jacksonville, FL
Tarnpa/Jacksonville, FL
St. Lucie/Jacksonville, FL
Palm Beach/Jacksonville, FL
Fernandina/Jacksonville, FL
Jacksonville/Jacksonville, FL
GULF OF MEXICO SECTION
Gulfport/Mobile, AL
Pascagoula/Mobile, AL
Mobile/Mobil^, AL
Brenton Sound/New Orleans, LA
Southwest Pass/New Orleans, LA
Atchafalaya/New Orleans, LA
Calcasieu Site "C"/New Orleans, LA
Sabine-Neches/Galveston, TX
Sabine-Neches/Galveston, TX
Sabine-Neches/Galveston, TX
Sabine-Neches/Galveston, TX
Galveston/Galveston, TX
Freeport/Galvestor. , TX
Matagorda/Galveston, TX
Mansfield Site 1-A/Galveston, TX
Brazos Site-1/Galveston, TX
PACIFIC OCEAN SECTION
San Francisco/San Francisco, CA
Humboldt/San Francisco, CA
Los Angeles/Los Angeles, CA
Chetco/Portland, OR
Coos Bay Site-"E"/Portland, CA
Coos Bay Site-"F"/Portland, CA
Coquille/Portland, OR
MCR Site-"E"/Portland, OR
MCR Site-"B"/Portland, OR
Siuslaw/Portland, OR
Umpqua/Portland, OR
Yaquina/Portland, OR
Nome/Anchorage, AK
Honolulu, Honolulu, HI
61
TOTAL
CUBIC YARDS
196,069
91 ,800
8,289,7146
97,3^9
"3,213
138,836
204,846
136,978
17,015
746,977
239,463
57,456
647,000
1,147,800
665,413
555,895
57,246
48,048
2,663,505
47, 148
16,091,808
723,962
235,968
360,047
2,933,239
21,602,793
6,250,890
6,820,000
630,708
237,740
651,652
58,080
3,839,190
312,390
539,891
364,53"
859,209
46,420,293
968,661
588,892
12,425
44,230
806,785
1,220,897
82,800
5, 134,048
89,082
246,563
317,132
378,191
13,000
399,000
10,301 ,706
72,813,807
TOTAL
TONS
264,693
123,930
10,610,869
124,606
55,312
194,370
286,724
232,863
28,925
1,269,860
362,511
86,978
960,794
804,483
988, 138
825,504
85,010
71,351
5,035,305
70,015
23,382,241
1,020,786
332,715
507,666
3,535,859
22,811,434
7,405,750
7,273,530
728,468
274,590
752,658
67,082
3,870,516
483,267
919,974
572,065
1,945,969
52,022,324
1,430,410
879,830
18.637
71,653
1,306,992
1,977,853
134,136
8,317, 158
144, 313
399,432
513,754
612,669
22,000
591,271
16,420, 108
91,824,673
-------
The type and quantities of materials being dumped in the ocean under
EPA permits are shown in Table 10 for the years 1973-1979. It is evident
from Table 10 that the Pacific Ocean disposal sites have had infrequent use
over the 7-year period represented. The same is generally true for the Gulf
of Mexico sites, particularly in 1978 and 1979. The Atlantic Ocean sites
receive the vast majority of ocean dumped industrial and municipal wastes.
Although no trend is apparent in the total amounts of material dumped at the
Atlantic sites over the years, reported quantities for 1980 and 1981 are
expected to be less than previous years as permittees are phased out.
Dredged materials for dumping result from COE maintenance dredging
activities, newly authorized projects, and from COE permittees. Table 11
indicates the quantity of dredged material disposed of at sites inside and
outside the 3-mile limit in 1979 (COE 1980). Disposal of material from COE
projects occurred using both COE and private contracted vessels.
Ocean Discharge
The Federal Water Pollution Control Act (FWPCA), also known as the
Clean Water Act, governs all discharges of pollutants into U.S. waters by
outfalls. Administration and implementation of the FWPCA is the
responsibility of EPA. Final regulations concerning ocean discharges were
published on October 3, 1980, and became effective 30 days later. These
403(c) ocean discharge criteria are applied to all applicants for National
Pollutant Discharge Elimination System (NPDES) permits involving new or
continuing discharges.
Of the 62,400 NPDES permittees nationwide, there are 232 land-based
dischargers with outfalls emptying into U.S. coastal waters. These ocean
discharges include 102 municipal wastewater treatment plants, 74 industrial
treatment plants, 25 steam electric plants, and 31 federal facilities. In
addition to these land-based ocean dischargers, there are about 3,000
offshore oil and gas exploration and production platforms which require
discharge permits (NACOA 1981).
The volume of municipal wastewater discharged to the ocean is extremely
large compared to ocean dumping. In southern California coastal waters
alone, over 1 billion gallons of treated wastewater are discharged per day
(NACOA 1981). For the Atlantic, Pacific, and Gulf coasts, over 3 billion
gallons of wastewater are discharged through marine outfalls each day.
Sewage sludge is also discharged through outfalls by Boston and Los Angeles.
The Los Angeles Hyperion plant discharges sewage sludge at the rate of about
160 tons per day. An average of about 200 tons per day of sewage sludge
from the Deer and Nut Island treatment plants in Boston is currently
discharged to President Roads. Ocean discharge of sewage sludge was
originally scheduled to end by December 31, 1981. However, because the city
of Los Angeles is unable to comply with this date, a recent court order has
extended the deadline. The Hyperion plant must cease discharging sludge by
1985.
62
-------
TABLE 10. TYPES AND AMOUNTS OF OCEAN DISPOSAL
(IN APPROXIMATE TONS) 1973-1979 (EXCLUDES DREDGED MATERIAL)
Atlantic Ocean
Waste Type
Industrial waste 3,
Sewage sludge 4,
Construction and
demol ition
Solid waste
Explosives
Incinerated (wood)
Incinerated (chemicals)
TOTALS 9 ,
Waste Type
Industrial waste 1,
Sewage sludge
Construction and
demolition debris
Sol id waste
Explosives
Incinerated (wood)
Incinerated (chemicals)
TOTALS 1 ,
1973
642,800
898,900
973,700
0
0
10,800
0
526,200
1973
408,000
0
0
0
0
0
0
408,000
1974
3,642,000
5,010,000
770,400
0
0
15,800
0
9,438,200
Gul
1974
937,700
0
0
0
0
0
12,300
950,000
1975
3,322,300 2,633
5,039,600 5,270
"395,900 314
0
0
6,200 8
0
8,764,000 8,227
f of Mexico
1975
119,600 100
0
0
0
0
0
4,100
123,700 100
1976
,200
,900
,600
0
0
,700
0
,400
1976
,300
0
0
0
0
0
0
,300
1977
1,783,600
5,134,000
379,000
100
0
15,100
0
7,311,700
1977
60,200
0
0
0
0
0
17,600
77,800
1978
2,548,000
5,535,000
241,000
0
0
18,000
0
8,342,000
1978
173
0
0
0
0
0
0
173
1979
2,577,000
5,932,000
107,000
0
0
36,000
0
8,652,000
1979
0
0
0
0
0
0
0
0
Pacific Ocean
Waste Type
Industrial waste
Sewage sludge
Construction and
demol ition debris
Solid waste
Explosives
Incinerated (wood)
Incinerated (chemicals)
TOTALS
1973
0
0
0
240
0
0
0
240
1974
0
0
0
200
0
0
0
200
1975
0
.0
0
0
0
0
0
0
1976
0
0
0
0
0
0
0
0
1977
0
0
0
0
0
0
12,100
12,100
1978
0
0
0
0
0
0
0
0
1979
0
0
0
998
0
0
0
998
63
-------
TABLE 11. DREDGED MATERIAL DISPOSED OF IN 1979
Inside 3-mi Limit
Grand
Cubic Yards % Total
Outside 3-mi Limit
Grand
Cubic Yards % Total
COE Programs
Corps vessel
Contract vessel
31,548,482
13,672,357
43.3
18.8
8,747,066
14,767,641
12.0
20.3
COE Permits
103 Authority
0.0
4,078,261
5.6
NET TOTAL
45,220,839
62.1 27,592,968
37.9
Source: COE 1980.
64
-------
Except for drilling muds and cuttings discharged to offshore waters,
wastes discharged from current NPDES permitted outfalls have little
similarity to manganese nodule processing waste. Existing outfalls are
designed to discharge liquids (mostly buoyant). The chemical and physical
characteristics of solids associated with discharges such as sewage or
sewage sludge differ greatly from manganese nodule rejects. This is
primarily because of the high organic content of sewage solids. Wastes
considered to be most analogous to manganese nodule processing rejects are
mine tailings. Mine tailings are not currently discharged to U.S. waters
although it is being planned for a mine near Ketchikan, Alaska. The
discharge of mine tailings to marine waters is employed most widely in
British Columbia, Canada. The comparison of the physical and chemical
characteristics of other wastes to manganese nodule processing wastes is
presented in Chapter 5. Appendix C presents a detailed discussion of
available information on mine tailings discharges to marine waters. A
comparison of observed impacts of mine tailings discharges is presented in
Chapter 7.
65
-------
5. CHARACTERIZATION OF NODULE PROCESSING REJECTS AND WASTES
AND COMPARISON TO OTHER WASTES
The complex composition of manganese nodules makes the development of
efficient processing and extraction technology a critical factor to the
viability of commercial manganese nodule mining. Nickel, copper, and
cobalt, the metals generally agreed to be of primary economic importance,
account for approximately 3 percent of the dry weight of an ore-grade
nodule. These metals are not present as discrete minerals but are
disseminated throughout the nodules in the manganese oxide and iron oxide
phases. For this reason, the value metals are not amenable to physical
concentration, and require extraction processing of the entire ore volume.
The ferro-manganese oxide matrix of nodules effectively scavenges trace
elements from the ocean. During metallurgical processing these trace
constituents must be either recovered as product, treated as impurities in
products, or relegated to the process wastes. Although trace elements occur
as inert compounds in manganese nodules, some are considered potentially
toxic or hazardous in ionic forms. In developing a metallurgical process to
economically extract value metals from nodules, the chemical forms and fates
of potentially toxic elements also require attention.
The majority of nickel, copper, and cobalt currently being produced
comes from sulfide ores processed in smelting operations utilizing
well-established extractive metallurgy. Some nickel and cobalt are produced
from laterites, silicate, and iron oxide deposits in which the value metals
are distributed throughout the mineral matrix, similar to manganese nodules,
and cannot be physically beneficiated. Reduction of the laterite oxide
matrix by pyrometallurgical or hydrometallurgical processes is required
before the nickel and cobalt can be recovered.
A summary of the state of knowledge of nodule processing methods and
resulting waste characteristics is provided in this section. This summary
is followed by a comparison to similar wastes, mining waste, dredged
material, and drilling muds and cuttings, which are currently disposed of in
marine waters. Throughout, the reader should note that a commercial-scale
processing will produce several discrete waste streams in addition to the
solids which remain after all the value metals have been extracted. These
other waste streams are described in this report but are not considered to
be part of the waste for which ocean disposal is being evaluated. These
other waste streams are relatively small in volume compared to the
processing rejects. It is assumed in this report that the design of the
processing plant will allow for separation and treatment of these wastes
independently of reject handling. Separate treatment versus disposal with
the rejects is an option which should be evaluated during the feasibility
studies for individual processing plants.
66
-------
It is important to note also that the data on chemical composition of
rejects from the various nodule processing schemes are based upon two
primary sources. These are the Dames and Moore studies (1977a and b) and
data from chemical analysis of rejects from a CUPRION-ammonia leach
processing pilot plant supplied by the Bureau of Mines, Avondale, Maryland.
The Dames and Moore values are theoretical in nature and represent a mass
balance of inputs to the plant among all wastes, products, and process
chemicals leaving the plant. These results are therefore not expected to be
completely representative of wastes from a pilot or operational plant. The
analytical results for the CUPRION-ammonia leach process are similarly not
expected to agree with the Dames and Moore mass balances or to be truly
representative of rejects from an operational processing plant.
SUMMARY OF EXTRACTION PROCESSES
In a comprehensive study of nodule processing activities contracted by
NOAA (Dames & Moore, Vol. I, 1977), five processing alternatives were
identified as the most likely options for first generation plants. Three of
these, reduction-ammonia leach, CUPRION-ammonia leach, and high temperature
sulfuric acid leach, are designed to recover three metals: nickel, copper,
and cobalt. Two systems, reduction-hydrochloric acid leach and
smelting-sulfuric acid leach, are capable of four metal recovery: nickel,
copper, cobalt, and manganese. All but the smelting-sulfuric acid leach
option are hydrometallurgical (chemical leaching) processes, while the last
includes a pyrometallurgical (smelting) step.
' Four general steps can be identified for each of the five processing
schemes discussed in this section:
f Separation of the value metals from the iron-manganese oxide
matrix
• Isolation of the value metals from each other and recovery
• Retrieval of reagents utilized in the extraction, and
• Waste disposal.
In the following discussion, the principal components of each process are
first summarized and then described in more detail.
All of the processes except the reduction/hydrochloric acid leach have
analogous processes already in existence to which they can be compared. The
wastes generated by the hydrochloric acid leach process can only be
characterized in a qualitative sense whereas much of the waste generated by
the other processes can be dealt with in more quantitative terms.
The majority of the wastes (85-95 percent) generated by the
reduction-ammonia leach, CUPRION-ammonia leach, and high temperature
sulfuric acid leach consist of leached rejects or slag and leached rejects
for the smelting-sul furic-acid leach process. The physical and chemical
characteristics of these rejects are inferred from analogous existent
67
-------
processes. The wastes generated by metals separation and purification of
nodules are quite different than those for conventional mineral deposits
because of the unique chemical nature of deep sea manganese nodules. The
susceptibility of the leaching of potentially toxic elements from rejects
discharged in the marine environment appears to be low while the stability
of the chemical constituents of the lime boil solids and electrowinning
sludges generated in the separation and purification steps are unknown.
REDUCTION-AMMONIA LEACH
The reduction-ammonia leach process (Figure 13) consists of a carbon
monoxide reduction step followed by solubilization of the value metals in an
ammonia solution. Copper and nickel are separated from the pregnant liquor
by liquid ion exchange and removed as electrowon cathodes. Cobalt is
precipitated as a sulfide which is reduced to form cobalt metal.
Prior to reduction, the nodules are dried at 175° C by direct contact
with combustion gases and ground to approximately 200 urn. The hot nodule
fragments are transferred to the reduction step where they contact carbon
monoxide produced by coal gasification at 625° C. The overall
reduction-oxidation reaction is:
(1) Mn02 + CO *- C02 + MnO
The reduction of manganese breaks down the matrix structure of the nodules,
enabling solubilization of the metals. The nodules are cooled with a water
spray and the carbon dioxide produced in reduction-step (1) is reacted with
the nodule slurry to form manganese carbonate. Oxygen introduced into the
system forms an insoluble iron oxide precipitate which is added to the
manganese carbonate tailings. After leaching the slurry with a solution of
ammonia and carbon dioxide, the tailings are separated from the solution in
a series of thickeners, washed, stripped of excess ammonia by steam, and
sent to waste containment. The solvent phase (pregnant liquor) now contains
much of the copper, nickel and cobalt originally present in the nodules.
The pregnant liquor passes through a counter-current liquid ion
exchange circuit where copper, nickel, and small amounts of cobalt and
ammonia are removed from the solution. To prevent buildup in the circuit,
cobalt and ammonia are periodically removed by precipitation with hydrogen
sulfide and washing with ammonium sulfate, respectively. Nickel and copper
are stripped selectively from the ion exchange liquid by varying the
strength of the electrolyte and recovered as electrowon cathodes. The
effluent leach solution is subjected to several processes, including sulfide
precipitation, oxidation, and solids separation, in order to remove
remaining copper, nickel, and zinc prior to cobalt recovery by reduction
with hydrogen gas.
Much of the ammonia and steam produced are recycled through the
process. Ammonia and ammonium carbonate are recovered after steam stripping
of the tailings by condensation. Ammonium sulfate used in the ion exchange
washing and generated in the purification of cobalt is reacted with slaked
lime. Ammonia is recovered from this mixture by steam stripping, leaving
gypsum (calcium sulfate) as a waste product.
68
-------
TO ASH
DISPOSAL
OTHERS
GAS
TREATMENT
pRocrss
HAURIALS
SUPPLIES
STORAGE
MAKE UP
WATER
HATfR
SUPPL»
AND
TREATMENT
TO PROCESS
AMMONIA
RECOVER*
ft
i U
HH,
— — v
4
i 1
i
i
1-
SIEAH
COBALT
RtCOVERT
Nl
ELECTRO-
WINNING
WASTE
CONTAIIIMENT
Ift
PROCESS
UASTCS
LEGEND
SOt IDS/SLURRIES
GASES
LIQUIDS
REFERENCE:
Dames and Moore, 1977
Figure 13. Reduction/ammoniacal leach process.
-------
The waste streams produced by this process include: the rejects
slurry, lime boil (gypsum) slurry, ash from combustion, sludges from gas
scrubbers, degraded organics recovered from the ion exchange circuit, spent
carbon from nodule reduction, electrowinning sludges, and plant runoff.
Processing alternatives which would influence the volume or composition
of the waste streams include: a low temperature hydrometallurgical
reduction (the CUPRION process described in the next section) and production
of ammonium sulfate by crystallization which would reduce gypsum production
by 18,500 tons/yr, and increase ammonia requirements by 4,300 tons/yr.
CUPRION-AMMONIACAL LEACH
The CUPRION/ammoniacal leach process (Figure 14) is quite similar to
the reduction-ammonia leach process except that the initial nodule reduction
step is performed in solution at low temperature by cuprous ion. Cuprous
ion is regenerated by reaction with carbon monoxide. Reduction proceeds by
the following reactions:
(2) Reduction: 2Cu(I) + Mn(IV) »-2Cu(II) + Mn(II)
(3) Regeneration: 2Cu(II) + CO + H20 »• 2Cu(I) + C02 + 2H+
The reduced nodule slurry passes through a series of thickeners with
the overflow being recycled. The thickened slurry is subjected to an
oxidizing ammonia leach in which iron forms a hydroxide precipitate which is*
added to the manganese carbonate rejects. Liquid-solid separations are made
in thickeners which provide added residence time for ammonia leaching.
Off-gases are scrubbed for ammonia recovery and the tailings are washed and
passed to waste containment. The pregnant liquor passes to liquid ion
exchange, where the remainder of the process is identical to the
reduction-ammonia leach metals purification scheme previously discussed.
The waste streams produced by this process include: the rejects
slurry, lime boil slurry, ash from combustion, sludges from gas scrubbers,
degraded organics recovered from the ion exchange circuit, electrowinning
sludges, and plant runoff. The major difference in the wastes produced by
the CUPRION and reduction-ammonia leach processes is in the amount of
fuel-related waste products. The initial low temperature nodule reduction
step of the CUPRION process consumes less fuel than the reduction-ammonia
leach process, with a concomitant decrease in the production of ash and gas
scrubbing sludges.
Process alternatives include a pyrometa11urgical reduction
(reduction-ammonia leach detailed in the previous section) and the
production of ammonium sulfate by crystallization which would reduce gypsum
production by 21,500 tons/yr and increase ammonia requirements by 5,000
tons/yr.
70
-------
TO ASH
DISPOSAL
SLUDGE
10
DISPOSAL
NODULES
RECEIVING
COAL
RECEIVING
0
£
i
GAS
CO
GAS
GENERATION
*. —
If STEAM
(OILERS
-* - - ^- -
ODE
REPARATION
"ll
f
REDUCTION
!!~=~~
AH10NIA
RECOVERY
'M
NH
COOALT
RECOVERY
n
3
<>=== =
i
II
II
II
II
II
II
II
1
== _ _ = _ =c>
PUIP
SEPARATION
HASHING
+
,1
LID
EXTRACTIO
H
, -/
LEACHING
s>
II
II
*-
1
• TO PROCESS
HASTE
CONTAINMENT
PROCESS
HASTES
LEGEND
SCH IDS/ SLURRIES
GASES
LIQUIDS
REFERENCE:
Dames and Moore, 1977
Figure 14. Cuprion/ammoniacal leach process.
-------
HIGH TEMPERATURE SULFURIC ACID LEACH
The high temperature sulfuric acid leach (Figure 15) consists of a high
temperature and pressure sol ubi 1 i zation of the ground nodules. Nearly all
of the value metals are extracted into the sulfuric acid solution. Copper
and nickel are recovered from solution by liquid ion exchange followed by
electrowinning. Cobalt is recovered from the raffinate by precipitation
with hydrogen sulfide and reduction by hydrogen gas.
Nodules are ground to approximately 200 urn, mixed into a slurry with
recycled pregnant leach liquor, and heated to 245° C. The hot slurry
contacts a 30 percent sulfuric acid solution at 35 atm pressure. After
dissolution of the value metal, the slurry passes through a heat exchange
step where the temperature is lowered to 50° C and waste heat is recovered.
Unreacted solids are separated from the slurry and washed of value
metals, the washings being added to the pregnant liquor. Limestone (calcium
carbonate) is added to the solution phase to adjust pH. This results in
precipitation of gypsum (calcium sulfate) which is removed in clarifiers.
The gypsum is washed of value metals and sent to waste containment. The
neutralized pregnant liquor flows to the copper ion exchange circuit.
The ion exchange process selectively removes copper and nickel from the
pregnant liquor. At acidic pH, copper is extracted by the ion exchange
medium. Adjustment of pH to more basic values, by the addition of ammonia,
allows nickel extraction in a second ion exchange circuit. The effluent
passes to cobalt recovery. The copper and nickel are stripped from their
respective ion exchange circuits by electrolyte that has been depleted of
the metals in the electrowinning process. The nickel ion exchange medium is
stripped of ammonia by washing and reaction with sulfuric acid. Prior to
electrowinning, the pH and conductivity of the electrolyte from the nickel
ion exchange circuit are adjusted with boric acid and sodium sulfate, and
dissolved organic materials are removed by absorption on activated carbon.
Copper and nickel are both recovered as electrowon cathodes.
Cobalt, and unextracted copper, nickel, and zinc are removed from the
nickel ion exchange raffinate by sulfide precipitation. The precipitate is
separated in a clarifier and pressure leached with air to preferentially
dissolve cobalt and nickel sulfides. The zinc and copper sulfides are
separated and sold as minor products. The remaining nickel/cobalt solution
is further processed with ammonium sulfate to remove nickel. Cobalt is
separated by evaporation, crystallization, and selective redissolution in a
strong ammonia solution, and recovered by hydrogen gas reduction. The
raffinate from the cobalt recovery is then reacted with slaked lime to
recover ammonia added as ammonia and ammonium sulfate.
Waste streams generated in the sulfuric acid leach process
include: rejects slurry, combustion ash, gas scrubber solids, lime boil
solids, spent carbon from activated carbon adsorption, degraded organics
from the liquid ion exchange circuits, and electrowinning sludges.
72
-------
SLUDGE
GASES
TO <
MAKE UP r --
HATER ~**
SLUDGE
DISPOSAL"*
NODULES
RECEIVING
WET
ORE
PREPARATION
K--z---'=\ ]
BOILERS
COAL
RECEIVING
us?. fTzj = 1
A" 1 A . ~ir
if 1 1r ••
1 m ^j i 4 ( PROCESS
!r «i i
4 ii <> *
COBALT
RECOVERY
" ft
ii U
II H,S
II '
II
i r ^
GAS
TREATMENT
^i PROCESS
HI
LII
EXTRACTION
AND
STRIPPING
o !!
»
« 1
II V
PROCESS
MATERIAL
SIIFPl Y
STORAGE
.»- TO PROCESS
UATER
SUPPLY
AND
TREATMENT
•*. TO PROCESS
N<
ELECTRO-
UINNING
[HI]
NH
••••I
[co | N
C^f: AMMONIA PN "*5TE
1^ "^ RECOVERY ADJUSTMENTS CONTAIIHENT
^^T*!r»
* " ^^^^^^^^ 1
0
J - ft
RAFF1NATE r.TnVr-T.nu
- iriiTDii EXTRACTION
l|J[,J3!j" AND BBB^ SOLIDS/SLURRIES
' '^ ~*A fj* ' ;> SASES/VAPORS
I
[J i c;;^> LIQUIDS
i! i
ii O
Cu
ELFCTRO-
ylNNINC
SB M
REFERENCE:
Dames and Moore, 1977
Figure 15. High temperature sulfuric acid leach process.
-------
Process alternatives include the elimination of the oxidation/pH
adjustment of the copper raffinate win ammonia prior to nickel extraction if
an extraction reagent could be found to selectively remove nickel in the
presence of cobalt. Another alternative would be the recovery of ammonium
sulfate by crystallization which would reduce gypsum production and increase
the ammonia requirement.
REDUCTION-HYDROCHLORIC ACID LEACH
The hydrochloric acid leach process (Figure 16) is based on the
reduction of manganese dioxide by the following reactions:
(4) Mn02 + 2HC1 »-Mn(OH)2 + Cl 2 (g)
(5) Mn(OH)2 + 2HC1 -+> MnCl2 + 2H20
The formation of soluble manganese chloride also releases copper,
nickel, and cobalt from the nodule matrix. In this process, copper and
nickel are selectively separated by liquid ion exchange and recovered as
electrowon cathodes. Cobalt is separated by solvent extraction, deposited
as a sulfide precipitate, and subsequently selectively leached into solution
and reduced by hydrogen gas to form cobalt powder. Manganese can be
recovered from the raffinate by several processes including evaporation of
the solution to produce an impure manganese chloride.
The chemical reduction of the manganese nodule matrix, reactions 4 and
5, is carried out on ground (approximately 200 urn) and dried nodules at a
temperature of 500° C. Solubilization of the iron content of the nodules by
the formation of iron chloride is minimized by a water spray which converts
ferric chloride to insoluble ferric hydroxide. The prevention of iron
solubilization is important to the subsequent separation and recovery of the
value metals. Unreacted HC1 is recovered for recycle and chlorine gas
(generated in reaction 4) is recovered, after drying by passage through
concentrated sulfuric acid, as a salable byproduct.
After the high temperature reduction step, metal chlorides are brought
into solution in HC1 . Copper is extracted from this solution (pregnant
liquor) using a liquid ion exchange medium. After separation of the copper
loaded organic phase from the metal-chloride solution from the ion exchanger
using strong sulfuric acid, the resulting copper sulfate solution is sent to
electrowinning producing cathode copper. The copper depleted sulfuric acid
solution is recycled to remove more copper from the ion exchange media.
The copper depleted chloride solution is neutralized with sodium
hydroxide and mixed with an organic solvent which selectively removes cobalt
from the solution. The cobalt is recovered by stripping it from the organic
solvent with recycled process water, precipitating it as cobalt sulfide with
hydrogen sulfide, and reducing it to cobalt powder with hydrogen gas.
Nickel is removed from the cobalt and copper-depleted chloride solution
using a liquid ion exchange media. The nickel is stripped from the ion
exchange media with depleted electrolyte from nickel electrowinning which
74
-------
LEGEND
SOUUS/SIUBMES
CAStS/VAPOBS
LIQUIDS
REFERENCE:
Dames and Moore, 1977
Figure 16. Reduction/hydrochloric acid leach process.
-------
contains nickel sulfate in solution as well as some sodium sulfate as an
additive and recovered from the nickel-sul fate solution as an electrowon
cathode.
The remaining manganese chloride solution which has been stripped of
copper, cobalt, and nickel can be dried to form impure manganese chloride.
The manganese can be purified in a high temperature electrolysis furnace
where it is separated in a pure molten form that can be cast into molds.
Because there are no close terrestrial analogs to the
reduction/hydrochloric acid leach process it is difficult to accurately
characterize the wastes produced. Comparison to the ferric chloride
leaching of copper sul fide ore indicates the potential for production of
large amounts of hydrous slimes which are difficult to settle and stabilize.
The largest waste stream will be fused salts which remain after purification
of manganese. Very little is known about the characteristics of these salts
including their solubility or susceptibility to leaching of potentially
toxic elements into the aqueous environment. Due to the lack of analogous
systems to which this process can be compared there will be no quantitative
analysis of the various waste streams.
SMELTING-SULFURIC ACID LEACH
The smelting-sul furic acid leach is a combined pyro- and
hydrometall urgical process (Figure 17) in which the iron and manganese
oxides are reduced at high temperature. The reduced nodules are converted
to a molten alloy in an electric furnace. Subsequent reoxidation of the
molten alloy and addition of coke and gypsum form two separable phases: a
slag containing manganese and iron oxides and a sul fide matte containing the
copper, nickel, and cobalt. Copper and nickel are recovered from the matte
following dissolution in sulfuric acid by ion exchange and
electrodeposition. Cobalt is recovered from the raffinate by precipitation
with hydrogen sul fide. A ferromanganese alloy can also be recovered from
the slag.
Prior to reduction, the nodules are dried and ground to approximately
200 urn. The dried nodules are mixed with coke and fed into a fluid-bed
roaster for reduction by carbon monoxide. The reduced nodules are smelted
with silica flux in an electric furnace at 1,425° C. The alloy phase
contains iron, nickel, copper, cobalt, and minor amounts of manganese, while
the slag is mainly composed of manganese, iron, and silica/calcium in the
proper ratio to maintain fluidity. Iron and manganese in the alloy are
removed to the slag by oxidation with oxygen gas. After separation of the
slag and alloy phases, the latter is mixed with calcium sulfate and coke to
form sulfides of the value metals.
The sulfide matte containing the value metals is quenched in a
granulation unit and formed into a slurry. The slurry is leached with
sulfuric acid at 150 psi and 110° C. The leachate, which now constitutes
the pregnant liquor, is separated from the residue by filtration. The
residue is removed to waste treatment. The pregnant liquor is pH adjusted
with calcium carbonate, resulting in the formation of calcium sulfate.
76
-------
REFERENCE:
Dames and Moore, 1977
Figure 17. Smelting process.
-------
Copper is removed from the solution by contact with an organic ion exchange
reagent. The organic medium is stripped of copper by contacting it with
depleted electrolyte from copper electrowinning. The nickel-rich raffinate
from the copper electrowinning process is then treated with ammonia to raise
the pH and oxidized to keep cobalt in solution prior to extraction of nickel
by liquid ion exchange.
Oxidation and pH adjustment cause the precipitation of iron, manganese,
magnesium, and aluminum initially extracted from the matte and carried in
the raffinate. Because precipitation under these conditions results in the
formation of hydrous slimes, the solution must be filtered. The solids are
sent to disposal.
The remainder of the process including nickel and cobalt recovery is
identical to that described for the sulfuric acid leaching process. Copper
and nickel are sold as electrowon cathodes and cobalt is recovered as a
sulfide precipitate followed by hydrogen reduction. Additionally, the slag
may be further processed to obtain a saleable ferromanganese product.
The waste streams produced by the smelting process include: leached
rejects and gypsum in slurry form from matte digestion, hydrous precipitates
(slurried), lime boil solids, granulated slag (slurried), gasification slag
(slurried), combustion ash, gas scrubber solids (slurried), smelting dust,
spent carbon, degraded organics, and electrowinning sludges.
Most alternatives in this process were eliminated as not adding
significant benefits. The greatest impact on waste production would stem
from the possible need to generate electrical power on-site to run the
furnaces. This would significantly increase the quantities of combustion
ash and gas scrubber solids produced.
WASTE STREAMS
Five process wastes have been evaluated: reduction-ammonia leach,
CUPRION-ammonia leach, high temperature sulfuric acid leach,
reduction-hydrochloric acid leach, and smel ting-sul furic acid leach. With
the exception of the reduction-hydrochloric acid leach, the waste streams
produced by each of these processes are similar in many respects. Where
sufficient data are available, similar waste streams from each process will
be compared on the basis of both physical and chemical characteristics.
Rejects
All of the processes considered discharge some form of reject in slurry
form. Rejects from the reduction-ammonia leach and CUPRION processes should
be quite similar in character since the nodules for both are originally
ground to the same size and are treated with the same lixiviant, ammonia.
Rejects from the sulfuric acid leach and the smelting process will each have
different qualities. Rejects from the sulfuric acid leach process result
from the extraction of ground nodules with sulfuric acid. Although the
smelting process also utilizes sulfuric acid as a lixiviant, the rejects
arise from the extraction of the sulfide matte phase.
78
-------
The reject waste stream comprises approximately 95 percent of the total
generated solids for both the reduction-ammoniacal leach and CUPRION
processes. The rejects are only approximately 85 percent of the total
solids generated by the high temperature sulfuric acid leach process because
of a higher lime boil solids production from the neutralization of excess
sulfuric acid. Smelting produces a small amount of matte rejects (1 percent
of solid wastes) because most of the waste solids are separated as slag
prior to leaching. The granulated slag comprises approximately 85 percent
of the total solid waste for this process and may be further processed to
recover ferromanganese or discharged as a waste product.
The physical characteristics of the rejects (Table 12) tend to be
similar for the processes evaluated. The waste streams range from 43 - 50
percent solids by weight and from 1.8 - 2.0 g/cc in bulk density. Also
shown are the yearly estimated solid and liquid fraction discharges,
assuming a nodule input of 3.7 x 106 mty for the hydrometallurgical
processes and 1.25 x 106 mty for the smelting process. As discussed later,
McKibbin (1981) has found the particle size of rejects from the CUPRION
process to be very small; 50 percent are less than 50 urn.
The chemical characteristics of the rejects discharged (Table 13) are
estimated for both the major and minor constituents. The pH of the waste
products will be adjusted to between 6.5 and 8.0 prior to discharge. An
additional concern may be the presence of reduced manganese (Mnll). In
seawater, Mnll may be oxidized to Mn IV by reaction with oxygen. While
Table 13 indicates that 12.5 percent of the hydrometallurgical rejects may
be Mnll, most of the reduced manganese will probably be present as a solid.
Table 18, shown later, also suggests that only a very small fraction of the
manganese would be in the dissolved state. Thus, oxygen consumption does
not apear to be a major concern. The oxygen consumption could easily be
measured on a representative sample of the waste.
The environmental impact of the potentially toxic metals in nodule
rejects disposed of in the ocean is determined by their availability to the
marine environment. It is expected that nearly all the metals will be
bonded to the solid phase or complexed and only extremely small percentages
will be in an ionic form. The Extraction Procedure (EP) toxicity test
discussed later for the CUPRION/ammoniacal extraction confirms the low
release of metals from tailings generated in this process. Similar low
dissolved concentrations can be inferred for tailings produced by the
reduction-ammonia leach process. The granulated slag produced by smelting
tends to be vitreous in nature and would be expected to be stable with
respect to leaching. Insufficient data exist for evaluating the leaching of
the high temperature sulfuric acid tailings.
Changes in some of the physical characteristics of the waste streams,
e.g., solids concentration, may result from attempts to promote better
settling characteristics when production actually is implemented.
Assessment of chemical characteristics can also be updated and improved as
wastes from pilot processes are generated and analyzed.
79
-------
TABLE 12. PHYSICAL CHARACTERISTICS OF REJECTS
Reduction/
Ammon i a
Leach
CUPRION/
Ammonia
Leach
Sulfuric
Acid
Leach
Smelting
Matte
Smelting
Granulated
Slag
Nature
Weight
Percent
Solids9
Density
(9/cc)
Dry Solids
Specific
Gravity
Grain Size3
(urn)
Solids
Discharge6
(mty)
Liquids
Discharge0
(mty)
slurry
45
1.8-2.01
N.D.
<74
slurry
47
1.9e
3.19e
<74
slurry
50
1.8
N.D.
<44
slurry
43
1.8-2.01
N.D.
<44f
2.7X106 b 3.5xl06 b 3.5xl06 b 7.3xl03 c' d
3.3x10'
870
,6 b
3.9x10'
1,000
,6 b
3.5x10
930
6 b
9.7x10
2.6
,3 c, d
Calculated from Dames & Moore 1977, Vol. Ill,
Based on 3.7x10 mty nodule input.
p
Leached rejects mixed with gypsum.
Based on 1.25 x 106 mty nodule input.
e Bureau of Mines analysis of leached rejects.
Estimate.
N.D. = No data.
granular
79
N.D.
N.D.
>l,700f
5.8x10
1.5x10^
40
5.
80
-------
TABLE 13. CHEMICAL CHARACTER OF REJECTS6
AND PERCENT OF ORIGINAL INPUT
Major
Constituents
in Percent
Potentially
Toxic
Constituents
(ppm)
Element
MnIIb
MnlV
Fe
Al
Si
Ba
La
V
Cr
Ag
Cd
As
Sb
Tl
Pb
R/A
Leach
12. 5C
(50)
12.5
(50)
8.5
(100)
2.7
(100)
6.8
(100)
4,645
(100)
1,680
(90)
418
(90)
10.5
(90)
0.35
(10)
2.3
(10)
29
(50)
31.4
(90)
23.2
(10)
523
(90)
CUPRION/
Ammonia
Leach
12.5
(50)
12.5
(50)
8.5
(100)
2.7
(100)
6.8
(100)
3,600
(100)
1,400
(95)
300
(80)
8
(90)
0.3
(10)
2
(10)
33
(70)
25
(90)
33
(20)
411
(90)
H?S04
Leach
(50)
(50)
3,610
(100)
744
(50)
36
(10)
8.1
(90)
0.28
(10)
—
4.5
(10)
2.7
(10)
90
(50)
409
(90)
Smelting
Matte
Rejects
— —
--
—
„*
ND
__
--
--
--
202
(50)
12.8
(1)
565
(10)
390
(10)
128
(1)
2,906
(5)
Smelting
Granula-
ted Slag
25
(100)
--
8.5
(100)
ND
ND
6,474
(100)
2,669
(100)
353
(50)
8.7
(55)
--
--
14.6
(45)
8
(10)
--
146
(45)
368
(45)
a All values calculated from Dames and Moore (1977, Vol. III).
Estimated worst case of unoxidized Mn.
c Upper value is concentration in rejects (in percent or ppm). Value in
parentheses is the percentage of the original concentration in nodules
present in the waste.
d ND = no data.
31
-------
Additional Waste Streams
Manganese nodule processing plants will generate wastes other than
rejects and slag, although the magnitude of these additional wastes will be
small by comparison. Some of these wastes have physical and chemical
properties which may be unique to nodule processing and are yet to be well
defined. These include: lime boil waste, electrowinning sludges, and
degraded organics from the ion exchange circuit. Other wastes such as fly
ash from coal combustion, water softening sludges, and plant runoff are
common to many industrial and manufacturing plants.
Lime boil solids constitute from about 1 percent of the total waste
rejects for the reduction-ammonia leach, CUPRION/ammoniacal leach, and
smelting processes to approximately 15 percent of the total waste for the
high temperature sulfuric acid leach. Grain size and slurry solids content
of lime boil solids appear to be similar to those of the reject slurry for
the high temperature sulfuric acid process (Table 14).
The concentrations of several potentially toxic constituents in the
lime boil waste streams are high (Table 14); however, their availability to
leaching is not presently known. Only thallium, in the reduction ammonia
and CUPRION/ammonia processes, and antimony, in the high temperature
sulfuric acid leach, are removed to the lime boil wastes in a proportion
greater than 10 percent of their original nodule concentration.
Electrowinning sludges (Table 15) account for less than 0.1 percent of
the total wastes generated, yet they tend to concentrate heavy metals. The
high lead concentrations result from the use of lead anodes in the
electrowinning process. At present, more detailed physical and chemical
characteristics of this waste stream are not available. No data exist on
the nature of the ion exchange circuit degraded organics which are a small
fraction of the wastes.
Wastes produced from coal combustion are not unique to nodule
processing; however, they constitute up to 3 percent of the solid wastes
generated (Tables 16 and 17). Smelting produces a smaller output of
combustion wastes than the other processes because a portion of the ash is
incorporated into the slag. The smelter output also does not reflect the
possible on-site generation of electricity to run the high temperature
furnaces. Solids density for fly ash is approximately 2.5 g/cc and mean
particle diameters are approximately 5 urn (Davison et al., 1975).
The pathways of toxic elements through coal-fired plants are well
documented in the literature (Klein et al ., 1975; Anderson and Smith, 1977;
Kaakinen et al., 1975; Gladney et al ., 1978; Cox et al., 1978; Dreesen et
al., 1977; and, Davison et al., 1975). Because fly ash is not unique to
nodule processing, and its properties are well documented, it will not be
discussed in detail.
The levels of wastes generated from nodule processing activities will
be dependent upon the use of recycle technologies, which are discussed
below. There is also the possibility for later recovery of other value
82
-------
TABLE 14. PHYSICAL AND CHEMICAL CHARACTERISTICS OF LIME BOIL SOLIDS
Physical Characteristics
Nature
Percent Solids3
Grain Size (urn)
Solids
Discharge
(mty)
Liquids
Discharge
(mty)
(mgy)
Reduction/
Ammonia
Leach
slurry
14
N.D.
Z.lxlO4
1.3xl05
34
a Calculated from Dames & Moore
b Estimated.
N.D. - No data.
CUPRION/
Ammonia
Leach
slurry
14
N.D.
2.1xl04
1.3xl05
34
1977, Vol. III.
Chemical Characteri
El ement
Ba
La
V
Cr
Ag
Cd
As
Sb
Tl
Pb
High Temp.
Sulfuric
Acid Leach
slurry
52
<53b
6.2xl05
5.7xl05
150
sties
Waste Concentration (ppm)
(Percent of Original Nodule Input)
Reduction/ CUPRION/ High Temp.
Ammonia Ammonia Sulfuric
Leach Leach Acid Leach
-
11,000
(1)
1,400
(2)
60
(4)
-
200
(7)
-
-
17,000
(60)
22
(0.03)
-
12,265
(5)
2,670
(5)
126
(8)
-
222
(7)
-
-
16,832
(60)
45
(0.06)
-
-
7.3
(0.4)
-
-
-
-
45.8
(20)
5.2
(0.6)
-
Smelting
Lime Boil
+ Neutral-
ization
slurry
60
N.D.
7.2xl04
5.9xl04
16
Smelting
(Neutrali-
zation
precipitate)
-
-
82
(0.7)
-
-
-
904
(7)
315
(4)
504
(1)
-
1977, Vol. III.
-------
TABLE 15. PHYSICAL AND CHEMICAL CHARACTERISTICS OF ELECTROWINNING SOLIDS
Physical Characteristics
Nature
Grain size
Discharge3
(mty)
Reduction/ CUPRION/
Ammonia Ammoniacal
Leach Leach
sludge sludge
N.D. N.D.
S.OxlO2 8-OxlO2
High Temp.
Sulfuric
Acid Leach
sludge
N.D.
8.4xl02
Smelting
sludge
N.D.
1.2xl02
a Calculated from Dames & Moore 1977, Vol. III.
N.D. = No
data.
Chemical Characteri
sties
Waste Concentration (ppm)
(Percent of Original Nodule Input)
Element
Ba
La
V
Cr
Ag
Cd
As
Sb
Tl
Pb
Reduction/ CUPRION/
Ammonia Ammoniacal
Leach Leach
-
-
1,230
(0.02)
20
(0.05)
283
(2)
1,613
(2)
920
(0.5)
108
(0.1)
6,467
(0.8)
18,600
-
-
791
(0.05)
20
(0.05)
262
(2)
1,742
(2)
1,100
(0.5)
120
(0.1)
6,966
(0-8)
19,600
High Temp.
Sulfuric
Acid Leach
-
-
9,880
(0.6)
26.6
(0.07)
-
3,496
(5)
1,728
(1)
754
(0.7)
4,028
(0.5)
-
Smelting
-
-
23
-
-
162
(0.1)
325
(0.08)
157
(0.06)
760
(0.05)
-
Source: Dames & Moore 1977, Vol. III.
84
-------
TABLE 16. PHYSICAL CHARACTERISTICS OF GASIFICATION ASH,
COMBUSTION ASH, AND OFF-GAS SCRUBBER SOLIDS
Reduction/
Ammonia Leach
Gasification
Combustion
Scrubber
CUPRION/
Ammoniacal Leach
Gasification
Combustion
Scrubber
High Temperature
Sulfuric Acid Leach
Gasification
Combustion
Scrubber
Smelting
Gasification
Combustion
Scrubber
Nature
slurry
solid
slurry
slurry
solid
slurry
slurry
solid
slurry
slurry
sol id
slurry
Grain
Percent Size3
Solids (urn)
20 N.D.
100 xX,5
20 XA,5
5 N.D.
100 *\,5
20 x<\,5
N.A. N.A.
100 x^5
20 x^5
10 N.D.
100 x>5
20 x-v5
Solids
Discharge
(mty)
4.7x10^
1.3x107
2.4xl04
*
4.0x107
3.3x!0j
2.4xl04
N.A.
3.3x107
1.2xl04
A
1.4x10,
4.7x103
9.5x10
Liquids .
Discharge
(mty) (mgy)
1.9xl05
-
9.5xl04
r-
7.6X105
" /]
9.5xl04
N.A.
~ A
5.0x10^
1.3xl05
~ A
3.8x10^
50
25
200
25
13
3.4xlOX
7
l.OxlO7
a From Davison et al. 1974.
b Calculated from Dames & Moore 1977, Vol. Ill and assumes 3.7x10 mty nodules
processed by hydrometallurgical methods and 1.25xlOb mty by smelting.
N.D. = no data.
N.A. = not applicable.
x" = mean grain size.
85
-------
TABLE 17- CHEMICAL CHARACTERISTICS
OF COMBUSTION ASH (FLY ASH)a
Al% 12.7
As 58
Cd 1.85
Co 41.5
Cr 127
Cu 133
Fe% 6.2
Hg 0.127
La 82
Mg% 1.8
Mn 496
Ni 98
Pb 75
Se 10.2
Sr 1,700
Ti 7,400
U 235
Zn 216
Values in mg/kg unless otherwise
noted.
Source: Klein et al. (1975) and
Ondov et al. (1975).
86
-------
metals such as molybdenum. The outputs derived here assume no recycling of
waste products and fixed nodule input rates.
UPDATE OF NOAA'S 1977 EVALUATION
Hubred (1980) provides an updated review and comprehensive bibliography
of the literature and patents which exist on manganese nodule processing and
extractive metallurgy. The bulk of this literature addresses the processing
scenarios favored by the four major ocean mining consortia; however, very
little of this material deals directly with process wastes.
As part of the Deep Seabed Hard Mineral Resources Act (PL 96-283),
enacted on June 28, 1980, NOAA was required to prepare a marine
environmental research plan for deep seabed mining. The resulting 5-year
program assigned waste disposal research a high priority. As part of this
program, the Bureau of Mines Avondale Research Center, with support from the
Spokane Research Center, has initiated a NOAA sponsored project entitled
"Analysis and Characterization of Potential Manganese Nodule Processing
Rejects." Although the mining industry has conducted tests of various
processing options, rejects from these tests cannot be considered
representative because they have been small-scale batch runs with frequent
system adjustments. Large-scale runs which would simulate commercial
operations have not yet been conducted and therefore characteristic process
reject material is not presently available. The first phase of the Bureau
of Mines project is to predict the characteristics of wastes from each of
the five .processing options considered most likely in early commercial
operations.
The initial phase of the Bureau of Mines study included several
analyses of a sample of steam-stripped rejects from a CUPRION process pilot
plant run made by Kennecott Copper Corporation in 1973. These rejects
indicate the general physical and chemical behavior of the material but are
not considered to be representative of the commercial process. The primary
reasons for non-representation given by Kennecott were:
• The rejects were produced from a pilot plant operation that
was purposely varied throughout the course of the campaign
so that the rejects were not produced under optimum
conditions.
• Leaching of nickel, copper, and cobalt from the ore was
below that which will be achieved commercially, so that
residual concentrations of these metals in the rejects may
be higher than will be obtained.
• The rejects were batch steam-stripped, while commercially
this will be done in a continuous manner using lime
addition. Lime treatment was not used during the batch
operations.
• Batch steam-stripping was not optimum nor complete so that
residual ammonia concentration in solution is well above
that rejected commercially.
87
-------
0 The rejects have been aging since 1973 which may have caused
changes in the nature of the rejects.
• Kennecott plans to recover molybdenum from the liquor
associated with the rejects and this procedure was not
carried out on the reject sample sent.
Tests conducted on this material by the,Bureau of Mines included
elemental analysis, evaluation of engineering properties, and an EPA
Extraction Procedure (EP) Toxicity Test. Table 18 is an analysis of the
reject material. Engineering property tests conducted by Bureau of Mines'
Spokane Research Center are presented in Table 19. The chemical and
physical characteristics of CUPRION reject material is in general agreement
with those predicted in Tables 12 and 13. To assess element availability,
an EPA leachate experiment based upon the EP Toxicity Test outlined in the
May 19, 1980, Federal Register was performed on the CUPRION reject material.
The results (Table 20) indicate that the leached amounts were well below the
permissible limits for silver, arsenic, barium, cadmium, chromium, mercury,
lead, and selenium. Other potentially important metals, especially copper,
were not analyzed because criteria for other metals, including copper, are
not specified in this test.
Additional work during phase one of Bureau of Mines' research project
study of processing rejects has resulted in the preparation of three draft
reports. These reports describe the mineralogical and elemental
characteristics of Pacific manganese nodules (Haynes, Law, and Barron 1981),
review the most feasible process flowsheets for first generation process
plants (Haynes and Law 1981a), and predict the physical and chemical
characteristics of nodule processing reject waste material (Haynes and Law
1981b). The latter two reports were primarily based upon the 1977 study
contracted by NOAA (Dames and Moore 1977b), but unlike previous work, they
attempt to predict the probable forms of elements present in processing
wastes. This information is necessary for assessing the potential toxicity
of reject material.
WASTE RE-UTILIZATION CONSIDERATIONS
An assessment of wastes associated with manganese nodule processing
cannot be complete without a discussion of the potential for reduction of
these wastes. Modern recycling and co-generation practices can be included
in the processing design, enhancing recovery efficiency, reducing pollution
hazards, and generating useful byproducts.
Japan's smelting industry best indicates the range of waste utilization
alternatives (Dresher and Rodolff 1981). In newer plants, secondary copper
extraction from slag and flue dust augments copper recovery to better than
95 percent. Slag is sold for cement manufacture. Up to 97 percent of the
sulfur released, collected as sulfur dioxide gas, is converted to sulfuric
acid in plants adjacent to the processor. For example, Mitsubishi's
Naoshima smelter produced 3.5 to 7 tons of sulfuric acid per ton of copper
recovered, while sulfur emissions were kept below one-half the regulation
88
-------
TABLE 18. ANALYSIS OF REJECT MATERIAL FROM A PILOT
PLANT TEST OF THE CUPRION PROCESS3
Element
Ag
Al
As
B
Ba
Be
Ca
Cd
Co
Cr
Cu
Fe
Hg
Mg
Mn
Mo
Ni
Pb
Sb
Se
Si
Sr
Tl
V
Zn
Percent
2.37
1.60
0.180
0.119
6.35
2.03
32.19
0.28
0.16
0.398
0.067
0.11
Solid
ppm
70.0
54.8
410.0
50.0
10.0
49.0
140.0
0.018
190.0
413.0
38.2
1.2
158.0
Liquid
ppm
<0.05
<0.5
0.025
6.06
0.27
<0.01
2.96
<0.05
0.10
<0.1
<0.05
<0.05
<0.0003
4.82
<0.02
62.9
<0.2
<0.01
<0.018
<0.031
22.4
0.34
0.11
0.06
<0.04
a These rejects are not representative of the commercial process but do give
an indication of the general physical and chemical behavior of the material.
Data supplied by U.S. Bureau of Mines, Avondale, MD.
89
-------
TABLE 19. ENGINEERING PROPERTIES OF REJECT MATERIAL
FROM A PILOT PLANT TEST OF THE CUPRION PROCESS9
Slurry density
Specific gravity, dry solids
Grain size
Atterberg limits
Permeability
Maximum density
Water content at maximum density
Triaxial shear strength
Settled density, column test,
30 days without bottom drain
with bottom drain
- 1.9, 41.8 percent solids by weight
(56.5 ft3/ton)
- 3.19
- 100 percent passing 74 urn (200 mesh)
50 percent passing 6 urn
0 percent passing 1 urn
- 45 percent liquid
41.2 percent plastic
3.8 plasticity index
ML (lean silt) soil classification
- 8.46 x 10 cm/sec at 95 percent
maximum density
- 90.1 lb/ft3
- 32 percent
- 38 degrees friction angle
5 psi cohesion
- 42.8 ft3/ton (24 percent reduction)
- 37 ft /ton (35 percent reduction)
a These rejects are not representative of the commercial process but do give
an indication of the general physical and chemical behavior of the material.
Reference: McKibbin (1981).
90
-------
TABLE 20. RESULTS OF AN EP TOXICITY TEST PERFORMED ON
REJECTS FROM A PILOT TEST OF THE CUPRION3 PROCESS BY THE
BUREAU OF MINES AVONDALE RESEARCH CENTER
Element
Ag
As
Ba
Cd
Cr
Hg
Pb
Se
Leached, ppm
0.3
0.004
4.4
0.06
0.14
0.019
0.6
0.002
Maximum Limit, ppm
5.0
5.0
100
1.0
5.0
0.20
5.0
1.0
a These rejects are not representative of the commercial process but do give
an indication of the general physical and chemical behavior of the material.
Data supplied by U.S. Bureau of Mines, Avondale, MD.
91
-------
allowance. Gypsum is a product of stack lime scrubbing which is used in
agriculture and in construction as wallboard. Use of smelter byproduct
gypsum allowed Japan to cease gypsum mining entirely in 1978.
In the United States, waste re-utilization prospects are being
investigated. The feasibility of ocean disposal of fly ash and scrubber
sludge from coal-fired power plants as artificial reef blocks has been
studied (Woodhead et al., 1979). The blocks were found to be stable in an
ocean environment, with no toxic effects on the biological communities which
they supported. In Hawaii, the utilization of manganese nodule processing
wastes as a volcanic soil conditioner is being investigated (Jenkins et al.,
1980). Slag could be used as road-bed material and in other construction
applications. It is also suggested that the scavenging nature of manganese
nodules may make the rejects suitable for stabilizing radioactive wastes.
The specific process utilized in manganese nodule extraction determines
the chemical and physical nature of the waste products and limits which
waste re-utilization procedures can be applied. Inclusion of such practices
may ultimately impact the final assessment of the acceptability of nodule
processing wastes for ocean disposal.
SUMMARY OF PROCESS TECHNOLOGIES
Four of the proposed manganese nodule processing systems have been
considered to be the most likely for first generation processing plants.
These four: reduction-ammonia leach, CUPRION-ammoniacal leach, high
temperature reduction-sulfuric acid leach, and smelting-sulfuric acid leach
have been tested in small-scale pilot tests by the major ocean mining
consortia. Data on large-scale system performance have been largely
theoretical. Based upon information provided in the Dames and Moore, EIC
study (Dames and Moore 1977b), waste streams have been identified and
characterized for each of the four processes (Tables 12 through 17). From
these data there appear to be only minor differences in the wastes from the
reduction-ammonia leach and CUPRION-ammoniacal leach processes. Wastes and
reject materials from these systems are summarized below and in Tables 21
through 23.
CUPRION- and Reduction-Ammonia Leach Processes
Rejects--
A fine-grained slurry with a bulk density of 1.8 to 2.0 gm/cc, 45 to 50
percent solids, pH 6.5 to 8.0 with reduced manganese (Mnllj present as MnC03
solid. Trace element content is high, but most are in insoluble forms or
appear to be tightly bound and not readily leached. Rejects account for
approximately 95 percent of the solid waste generated by these processes.
Lime Boil Solids--
A fine-grained slurry consisting primarily of gypsum (calcium sulfate)
with a high liquid fraction (86 percent). These wastes may contain
considerable amounts of lanthanum, vanadium, chromium, cadmium, and
thai!ium.
92
-------
TABLE 21. CHARACTERISTICS OF CUPRION- AND REDUCTION-AMMONIA WASTE STREAMS
Form
Leached Tails Slurry
Lime Boil Slurry
Solids
Electrowinning Sludge
Sludge
Combustion Slurry
Rejects
Bulk
Density
(g/cc)
1.8-2.0
ND
ND
.1.3a
Percent
Solids
45-50
v!4
ND
20a
Percent
of Total Metals
Solid Waste Present
^95 All in-
coming
*1.0 La, V, Tl,
Cr, Cd
«0.5 Pb, Cd, Tl,
As
^2.0 All in-
coming plus
others
Availability
of Toxicants
Relatively
Unavailable
Unknown
Unknown
Relatively
Unavailable
Comments
Bulk density and
percent sol ids do
not include dis-
charge of combus-
tion ash generated
as a sol id.
For gas scrubber and gasification rejects only.
TABLE 22. CHARACTERISTICS OF HIGH TEMPERATURE SULFURIC ACID WASTE STREAMS
Leached Tails
Lime Boil
Electrowinning
Sludge
Combustion
Rejects
Form
Slurry
SI urry
Sludge
Slurry
Bulk
Density
(g/cc)
-\-1.8
ND
ND
-U.3a
Percent
Solids
^50
,52
ND
20a
Percent
of Total
Solid Waste
,85
,15
«0.5
,1.0
Metals
Present
All in-
coming
Pb, V, Cd,
Tl, As
All in-
coming plus
others
Availability
of Toxicants
Relatively
Unavailable
Unknown
Unknown
Relatively
Unavailable
Comments
Bulk density and
percent solids do
not include com-
bustion ash gener-
ated as a solid.
For gas scrubber and gasification rejects only.
93
-------
TABLE 23. CHARACTERISTICS OF SMELTING WASTE STREAMS
Form
Leached Matte Slurry
Tail ings
Granulated Slurry
Slag
Lime Boil Slurry
Sol ids
Electrowinning Sludge
Sludge
Combustion Slurry
Rejects
Bulk
Density
(g/cc)
1.8-2.0
ND
ND
ND
^1.3a
Percent
Percent of Total Metals
Solids Solid Waste Present
°A3 1-2 Ag, As, Sb,
Tl, Pb
^79 <&$ Most in-
coming
60 'ulO As, Sb, Tl
ND «0.5 Pb, Cd, As,
Sb, Tl
10-20a ^4.0 All in-
coming plus
others
Availability
of Toxicants
Unknown
Unavailable
Unknown
Unknown
Unavailable
Comments
Bulk density and
percent solids do
not include combus-
tion ash generated
as a solid.
For gas scrubber and gasification rejects only.
-------
Combustion Ash and Gas Scrubber Solids--
Principally spent carbon and dusts from nodule reduction (slurry) and
combustion ash from steam generation (solid), these wastes are typical of
many other industrial processes.
Electrowinning Solids —
This sludge from the electrowinning extraction circuit is small in
total amount, but may contain elevated concentrations of lead and cadmium
from spent anodes.
High Temperature Sulfuric Acid Leach
The slurry will consist of sulphate salts and oxides of aluminum,
silicon, iron, and manganese. This reject material will be neutralized to
pH 6.0 to 6.5 prior to disposal. The volume of rejects and lime boil solids
together are slightly greater than the volume of nodules input.
Rejects--
A slurry with fine-grained solids similar to CUPRION and reduction
ammonia rejects. This reject material will be neutralized to pH 6.0 to 6.5
prior to disposal. Trace element content is high but solubility is probably
very low. Considerable reduced manganese may be present in the liquid
fraction.
Lime Boil Solids--
Due to the reagent requirements for pH adjustment of acidic spent
liquors, this waste stream discharges more material than the other process
options (15 percent of the total solids); however, it remains similar in
physical and chemical characteristics.
Electrowinning Solids--
Similar to the other processes, this sludge represents a small
percentage of total wastes discharged, but may contain high levels of
several heavy metals.
Combustion Ash and Gas Scrubber Solids--
Characteristics of this waste are similar to those for the ammonia
processes.
Smelting-Sulfuric Acid Leach
Smelting-sulfuric acid leach differs from the other process options in
that it includes a pyrometall urgi cal step with separation of the ore into
slag and matte.
95
-------
Rejects--
Two distinct rejects must be considered here, smelting matte and slag.
Both are rejected as a slurry, but the matte is fine-grained material
similar in nature to the high temperature sulfuric acid tailings. The slag
accounts for the bulk of the rejected material and consists of a coarse,
granulated slurry. The majority of the trace constituents considered
potentially toxic are in the slag fraction where they are expected to be
bound in the inert, vitreous solids phase.
Lime Boil Solids--
Much of this slurry is from the acid neutralization step following
sulfuric acid leaching and metal extraction. This material is similar to
that of the high temperature sulfuric acid wastes, but since only the
smelting matte is leached, discharge amounts are lower.
Electrowinning Solids-
Similar to the sludges from the other processes but of lower volume and
trace element content (the majority of the trace elements are in the slag).
Combustion Ash and Gas Scrubber Solids—
Similar to other processes but less volume as much of the spent carbon
from the reduction-smelting step is incorporated into the slag.
Preliminary data indicate that rejects from the three
hydrometallurgical processes considered and slags from smelting are fairly
resistant to leaching of potentially toxic metals. As discussed in Chapter
7, metals in ionic form are generally of greatest environmental concern. It
is clear that the majority of trace metals associated with slags and rejects
will be chemically bound in solid mineral phases and not as dissolved ionic
species. Concentrations of metals in the dissolved state as shown in Tables
18 and 20 are relatively low and most dissolved metals may be complexed and
therefore not in an ionic form. The detailed nature of trace element
partitioning in rejects can only be determined from further tests of
representative wastes. The other nodule processing waste streams such as
the lime boil solids, degraded ion exchange liquids, and electrowinning
sludges will also require more characterization based on pilot plant
operations before further conclusions can be drawn.
COMPARISON TO OTHER WASTES
Knowledge of the chemical characteristics of manganese nodule
processing waste, as explained above, is indirect. The predicted chemical
composition of the waste is based upon inferences drawn from knowledge of
the probable processing methods. The one available analyses of the CUPRION
process waste produced from pilot plant tests cannot be assumed as
representative of waste from full-scale plants.
96
-------
In view of the lack of detailed information on the chemical composition
of nodule processing waste, comparison to other wastes can be important.
The characteristics of mining wastes, dredged material, and drilling muds
and cuttings are described in this section. The important characteristics
of these materials are the chemical composition of the solid phase of the
waste and, of particular importance, the concentration of dissolved
pollutants associated with the discharge or that can be leached from the
solids after discharge.
Heavy metals are the pollutants of concern. Manganese nodule
processing wastes are expected to be essentially free of organic compounds.
Because of this lack of organic material, mining waste is most directly
comparable to manganese nodule processing rejects. Silt- and clay-sized
dredged material is similar to nodule processing wastes with regard to
metals concentrations and chemical behavior. However, they can also contain
up to 10 percent or more organic material which can serve as a food source
to organisms in the marine environment. This is also true of drilling muds
and cuttings. For this reason the primary emphasis is placed upon the
characteristics of mining wastes. Discussion of the observed biological
impacts of mining waste, dredged material, and drilling muds and cuttings is
presented in Chapter 7.
A direct comparison is made in Tables 24 and 25 of the chemical
characteristics of the wastes based upon data presented in Appendix C. It
should be noted that the concentration ranges presented for mining waste,
dredged material, and drilling muds and cuttings are based upon many
measurements of actual wastes. The values for manganese nodule processing
waste are based upon a single analysis of effluent from a CUPRION process
pilot plant. Metal recovery of the plant was not at levels as high as
expected from a full scale, operational plant. Accordingly, the
concentrations of copper, molybdenum, and nickel in the solid phase of the
rejects as shown in Table 24 are considered to be higher than would be
expected from a full-scale plant. Improved value metal recovery may also
reduce the concentration of other associated metals in the rejects. Also,
the manganese concentration in rejects from a four-metal process would be
substantially lower.
Table 25 presents a comparison of the chemical composition of the
dissolved components in the four waste materials. Before discussing the
values presented, the reader should carefully note the meaning of the symbol
"<" which indicates "less than". The value of < 50 ug/1 means, for example,
that the analytical method employed could not detect concentrations below 50
ug/1. The true concentration could be 49 or 0 ug/1. It is known only that
the concentration is not greater than 50 ug/1.
The dissolved phase chemical analysis was performed on the same CUPRION
process sample from which the solid phase was done. As such, the results
are similarly unrepresentative. This is particularly evident in the
molybdenum concentration (63,000 ug/1). It is anticipated that molybdenum
will be recovered in a full-scale plant.
97
-------
TABLE 24. SUMMARY COMPARISON OF SOLID PHASE CHEMICAL
COMPOSITION, mg/kg
Manganese Nodule Mining
Processing Waste3 Waste
As
Cd
Cr
Cu
Fe
Hg
Mn
Mo
Ni
Pb
Zn
55
49
140
1,119
63,500
0.018
321,900
190
2,800
413
1,100
2.2 to 6
0.14 to 0.3
4.9 to 13.9
170 to 370
15,800 to 17,000
<0. 00005 to 0.005
78 to 325
5.4 to 15.8
9.3
3.9 to 6.7
26.9 to 49.9
Dredged
Material
0.03 to 23
0.02 to 7
0.25 to 190
0.23 to 449
100 to 95,000
0.01 to 2.7
188 to 570
N.D.
1.2 to 82
0.25 to 600
0.25 to 1,246
Drilling
Muds and
Cuttings
<1.0 to 3
<1.0 to <2.0
2 to 1,007
2 to 28
N.D.
<1 to 2.2
N.D.
N.D.
1 to 21
<1 to 24
12 to 236
N.D. = no data.
Results are from one analysis of wastes from a CUPRION process pilot plant
and are considered not to be representative of waste from a full-scale
plant. Some values are expected to be lower for full-scale plants.
< = less than. The value of <50 mg/kg means, for example, that the
analytical method employed could not detect concentrations below 50 mg/kg.
It is known only that the concentrations is not greater than 50 mg/kg.
98
-------
TABLE 25. SUMMARY COMPARISON OF DISSOLVED PHASE CHEMICAL
COMPOSITION, ug/1
Manganese Nodule Mining
Processing Waste3 Waste
As
Cd
Cr
Cu
Fe
Hg
Mn
Mo
Ni
Pb
Zn
25
<50
<100
<50
<50
<0.3
<20
63,000
<200
<10
<40
14 to 88
<0.1 to <0.5
0.6 to <5
3 to 280
8 to 1,200
<0.1 to 0.24
1 to 4
100 to 300
<1 to <10
<1 to 5
0.8 to 170
Dredged
Material
1 to 24
0.2 to 2.9
0.5 to 30
1 to 8
2.5 to 33
0.01 to 1.8
30 to 2,300
N.D.
2 to 21
0.9 to 12.5
10 to 70
Drilling
Muds and
Cuttings
N.D.
60 to 80
<100 to 1,080
N.D.
N.D.
N.D.
N.D.
N.D.
N.D.
<500
60 to 230
N.D. = no data.
a Results are from one analysis of wastes from a CUPRION process pilot plant
and are considered not to be representative of waste from a full-scale
plant.
< = less than. The value of <50 ug/1 means, for example, that the
analytical method employed could not detect concentrations below 50 ug/1.
It is known only that the concentrations is not greater than 50 ug/1.
99
-------
The comparison of dissolved metals concentrations shown in Table 25
indicates, with the exception of molybdenum and nickel, that all metals
concentrations are within the range observed for other wastes discharged to
the marine environment.
Table 26 presents a comparison of the dissolved metals concentration in
the nodule processing waste to EPA water quality criteria. Note that there
are two types of receiving water criteria; 24-h average criteria, also known
as the chronic value, and the maximum at any time criteria, also referred to
as the acute value. The 24-h average or chronic value is designed to apply
to continuous discharges such as outfalls. The composition of the effluent
can vary during the day and produce receiving water concentrations which at
times exceed the criteria value. The average value of several samples taken
over the 24-h period must not exceed the criteria, however.
The maximum at any time, or acute, criteria also apply to continuous
discharges but are based upon short-term bioassays. Marine organisms are
expected to survive short term exposures to concentrations near the upper
limits of the criteria values. The acute criteria are, therefore, higher
than the chronic criteria. The acute criteria are, therefore, most
applicable to ocean dumping which is a periodic and not a continuous
process.
A second important point to consider is that the water quality criteria
apply to ocean dumping or ocean discharges after initial dilution. In the
case of ocean dumping, this is the concentration in the wastefield 4 hours
after discharge. Under the 403(c) regulations which regulate continuous
discharges from outfalls, initial dilution is the amount of dilution which
can be achieved within a mixing zone. The mixing zone is defined as, "the
zone extending from the sea's surface to the seabed and extending 100 meters
in all directions from the discharge points(s) or to the boundary of the
zone of initial dilution as calculated by a plume model...". The later part
of the definition has little relevance to negatively buoyant jet discharges
because no model presently exists which can be readily applied to describe
their behavior.
The required initial dilutions presented in Table 26 are computed by
simply dividing the metal concentration by the criteria value. Results less
than zero are shown as zero or, in other words, no initial dilution would be
necessary in order to meet water quality criteria.
Table 26 lists metals for which water quality criteria have been
established. As shown earlier, other potentially toxic metals, for which no
criteria has been established, are also expected to be present in manganese
nodule processing waste. These metals must be evaluated further. For the
metals listed in Table 26, the dilution needed to meet current water quality
criteria is small. Also recall that the listed metals concentrations are
probably conservatively high. Initial dilutions achieved during ocean
dumping are expected to be at least an order of magnitude greater than the
2:1 dilution listed in Table 26. Dilutions achieved through outfall
discharge of nodule processing rejects may be less than 28:1 depending upon
the definition of the mixing zone used.
100
-------
TABLE 26. COMPARISON OF DISSOLVED METALS CONCENTRATIONS
TO WATER QUALITY CRITERIA FOR MARINE WATERS
As
Cd
Cr
Cu
Hg
Ni
Pb
Zn
Nodule Processing
Waste Dissolved
Metals Concentrations3
ug/1
25
<50
<100
<50
<0.3
<200
<10
<40
EPA
Water
Quality
Criteria,
24-h Avg.
ug/1
no
criterion
4.5
18
4
0.025
7.1
25
58
Dilution
Required
for
Outfallb
no
criterion
11:1
6:1
13:1
12:1
28:1
0
0
EPA
Water
Quality
Criteria,
Maximum
ug/1
508
59
1,260
23
3.7
140
668
170
Dilution
Required
for
Dumping
0
0
0
2:1
0
2:1
0
0
a Results are from one analysis of wastes from a CUPRION process pilot plant
and are considered not to be representative of waste from a full-scale
plant.
b Assumes concentration in waste equal to "<" value; e.g., <50 = 50.
Criteria values from Federal Register, November 28, 1980.
101
-------
In summary, the ocean disposal of manganese nodule processing waste is
expected to meet present water quality criteria after initial dilution.
More information on the composition of the waste from a full-scale plant is
needed to be conclusive. It should be remembered however that substantial
changes could be made in the water quality criteria by the time the first
discharge dumping application is submitted; late 1980s. The 28:1 dilution
needed to meet chronic criteria may be harder to meet for an outfall. The
403(c) mixing zone definition is impractical to apply to negatively buoyant
jets. Less is also known about the behavior of such jets and the nature of
dilution.
102
-------
6. REPRESENTATIVE DISPOSAL AREA CHARACTERISTICS
The purpose of this section is to provide a summary description of the
physical and biological characteristics of general areas where disposal of
manganese nodule processing waste may possibly occur in the future. This is
a necessary step so that the potential impacts of ocean disposal can be
discussed with reference to known marine resources. A more detailed
description of representative area characteristics is presented in
Appendix D.
No specific locations have been proposed publicly for nodule processing
plants or for waste disposal sites. Nor is this section intended for
purposes of site selection. Four regions have been chosen for general
discussion on the basis that land-based processing plants could be located
within the region due to their proximity to the Pacific Ocean nodule mining
area. These regions are classified as
• Western Gulf of Mexico
• Southern California Bight
• Pacific Northwest
• Hawaii.
Within each region more specific areas have been described to illustrate how
characteristics vary with depth and distance offshore. In general,
nearshore, midshelf, and deepwater (seaward of the shelf) areas are
described. A summary of important physiographic and bathymetric features
and circulation patterns is provided for each region. Similarly, a brief
description of the significant physical oceanographic characteristics (e.g.,
temperature, salinity, density, dissolved oxygen, and currents) is provided
for the specific areas within each region. In addition, biological
oceanographic characteristics of each region are summarized for each
specific area.
This information represents a synthesis of available literature and is
not intended to be a detailed analysis as would be needed for site
selection. However, this information is sufficient to form the basis for
the preliminary estimates of the fate of discharged wastes. These
estimates, which are also presented in this chapter, are based upon the
predictive relationships developed in Chapter 3.
103
-------
WESTERN GULF OF MEXICO
Physical Characteristics
The Gulf of Mexico is a relatively shallow (3,600 m maximum depth)
semi-enclosed water body connected to the Atlantic Ocean by the Florida
Straits and the Caribbean Sea by the Yucatan Channel (Figure 18). A
simplified view of the basin's configuration is obtained by grouping similar
bathymetric features and characteristics into distinct physiographic
subdivisions as shown in Figure 19. The basin is asymmetrical with its
greatest depths occurring west of 90° W longitude, while the two primary
channels for water exchange are situated 3 to 6° to the east and trend in a
general northwest-southeast orientation. This bathymetric configuration is
a primary influence on the Gulf's circulation and oceanographic
characteristics.
The large scale circulation pattern in the Gulf of Mexico is dominated
by two current systems; the strong, well-defined clockwise Loop Current in
the east, and an elongated, less permanent clockwise circulation cell
located over the deeper areas of the central and western Gulf. The Loop
Current enters the eastern Gulf through the Yucatan Straits, exiting through
the Straits of Florida (Leipper 1970; Maul 1977). The Loop Current exhibits
a definite growth and decay cycle which begins with the Loop Current
increasing its penetration into the Gulf to a stage where a large eddy
separates from the loop, and drifts and spreads into the western Gulf
(Behringer et al., 1977; Elliot 1979). However, significant seasonal and
yearly variation has been noted in this pattern (Molinari 1978* 1980; Maul
1977).
Characteristics of Representative Areas
Two general locations are considered as representative of potential
nodule processing waste disposal sites; a midshelf site and a deepwater
site. In addition, conditions at an upper-slope site are also described
because of the site's historical use for chemical waste disposal (Atlas et
al., 1980). Shallow nearshore waters and a gentle bottom slope effectively
preclude disposal of nodule processing wastes through a nearshore outfall
pipe.
Oceanographic data from Texas ASM western Gulf synoptic oceanographic
surveys in February and March, 1962, serve to define selected parameters in
each area. Stations 120, 122, and 92 shown in Figure 19 are considered
representative of mid-shelf, upper-slope, and deep basin areas,
respectively. In synthesizing the physical oceanographic nature of each
area, many technical documents were reviewed in addition to the Texas A & M
transect data. Nevertheless, the data set available for compiling general
area characteristics was found to be limited (e.g., seasonally or for a
particular parameter).
104
-------
30°
25°
20°
200m.
1000m.
FLORIDA STRAITS
till
OS-
85"
80°
REFERENCE: Nowlln 1972
Figure 18. Bathymetry of Gulf of Mexico.
105
-------
Sigsbee Knolls
ABYSSAL PLAIN
20° -
REFERENCE: after Ewing et al., 1958.
Figure 19. Physiographic subdivisions of the Gulf of Mexico
and selected stations of Hidalgo 62-H-3 cruise of
March 22-27, 1962.
106
-------
Mi d-Shelf—
Nearshore surface salinities of the mid-shelf region are typically low
due to intrusion of freshwater from continental drainage (Nowlin 1972).
Salinity increases with depth and with distance offshore. Due to
significant mixing, temperatures are relatively uniform with depth. This
temperature-salinity combination results in a typical March density gradient
of 1.0 sigma-t units in the upper 30 m (98 ft). Dissolved oxygen levels are
relatively uniform with depth, decreasing from 6.5 to 5.8 ml/1.
Current measurements on the shelf indicate that the currents are
typically aligned alongshore, are highly seasonal, and exhibit layering of
contrasting flow in late spring and during summer (Armstrong 1980). Mean
surface currents are downcoast to the southwest throughout the year, with an
onshore component in summer. Mid-depth to bottom flows are directed upcoast
and offshore (east and southeast, respectively) from May to August, and
downcoast the remainder of the year. Deeper eastward currents do occur
during some winter periods. Mean current speeds decrease with depth, being
approximately 15 cm/sec near the surface and decreasing to 10 cm/sec near
the bottom. Seasonally, speeds are lowest in summer and highest in the fall
and spring. Flow variability is principally due to wind shifts and tidal
currents.
Upper-Slope--
Further offshore, the salinity is relatively constant at 35.9 ppt in
the upper 50 m (164 ft), increasing somewhat between 100 and 200 m (328 and
656 ft) to 36.1 ppt, and thereafter decreasing gradually with depth to
approximately 35 ppt. In March, temperature measurements indicate a gradual
reduction in temperature from approximately 20° C near the surface to 4° C
at 1,000 m (3,280 ft). The resultant density profile consists of a small
positive density gradient to 50 m (164 ft) depth, a sharp density increase
between 50 and 120 m (164 to 492 ft), tapering off to a relatively small
increase with depth thereafter. Dissolved oxygen concentrations decrease
from surface values of 6.5 to 7.0 mg/1 to a minimum of approximately 3.5
mg/1 at between 250 and 400 m (820 and 1,312 ft), and increase to 5.0 mg/1
at 1,000 m (3,281 ft). Geostrophic flow is predicted to generally be
eastward, varying from 25 cm/sec near the surface to less than 5 cm/sec
below 350 m (1,148 ft). At the industrial-chemical waste disposal site A
(water depths of 900-1,400 m), absol ute. near-surface currents on the order
of 26 cm/sec or less have been measured (Mungall and Home 1978).
Deep Basin--
Beyond the slope, over the abyssal plain, salinities commence at 36.1
ppt at the surface, increase slightly to a maximum of 36.35 ppt at 125 m
(410 ft) and decrease sharply thereafter, reaching a minimum of 34.89 ppt at
580m (1,902 ft). Below greater depths, salinity approaches 34.97 ppt.
Temperature decreases rather slowly from 22.3° C at the surface to 20.5° C
at 125 m (410 ft). At this depth however, a pronounced gradient occurs,
with temperature decreasing 15° C in the next 800 m (2,624 ft). Beyond this
depth the temperature remains relatively constant at 4.2° C. The associated
107
-------
density profile indicates a uniform surface density of 25 sigma-t units in
the upper mixed layer [in this case down to 25 m (82 ft)]. A relatively
sharp pycnocline occurs beyond this point, with sigma-t values increasing
another 2.75 units by the 1,000 m (3,281 ft) depth. Thereafter, the density
remains relatively constant at 27.75 sigma-t units.
Dissolved oxygen concentrations of 6.1-6.9 mg/1 in the upper 100 m (328
ft) decrease sharply to a characteristic minimum of 3.83 mg/1 at
approximately 250 m (820 ft). Beyond this depth, dissolved oxygen
concentrations increase, at first relatively slowly to 4.9 mg/1 at 775m
(2,542 ft), then quickly to 5.91 at 70 m (3,182 ft), and thereafter again
slowly to a maximum value of 4.83 mg/1 at 2,920 m (9,579 ft).
Calculated geostrophic flows for a deep-basin area indicate westward
surface currents of up to 35 cm/sec, decreasing to no current at
approximately 350 m (1,148 ft). Beyond this depth, very low flows are
indicated, eastward at up to 1.2 cm/sec down to 550 m (1,804 ft), and
thereafter again westward at greater depths, but at less than 1 cm/sec.
Fate of Material
The fate of instantaneously dumped material is considered at Stations
120, 122, and 92 (Figure 19). The 4 hour fate computations using the
methods described in Chapter 3 are summarized in Table 27. As can be seen
from these results, the cloud impacts the bottom at the shelf site. Due to
vertical dispersion, which is anticipated to be high due to the vertical
shear in the horizontal currents, the finer particles may be suspended
longer than otherwise expected. At the upper continental slope site
(No. 122) the cloud imoacts the bottom if its initial density equals 2.0
g/cm3 but not 1.4 g/cm3. The cloud is trapped for initial densities of at
least 1.4 g/cm3 at the deeper continental rise site (No. 92). In all three
of these sites the area of impact after 4 hours is less than 0.5 km2, and
the dilutions are high except at the shelf site. Since the current speeds
are less than 5 cm/sec at depths below 350 m, the center of mass is expected
to travel no more than 0.7 km in 4 hours time.
Discharge of a negatively buoyant fluid from a marine outfall requires
a bottom slope steep enough so that the fluid travels away from the outfall
in a flow driven by gravity. While the minimum slope necessary is dependent
on the particulars of a given situation, the slope is probably on the order
of several degrees. Figure 18 indicates that in the western Gulf of Mexico,
the bottom slopes near the shoreline are but a fraction of one degree except
at the tip of the Mississippi River delta. Hence, construction of an
outfall is impractical unless steep bottom slopes exist locally.
Marine Biological Characteristics
Oceanic environments far beyond the continental shelf in the Gulf of
Mexico are characterized as oligotrophic. Nutrient concentrations are
typically quite low within the euphotic zone, and phytoplankton standing
stocks and primary productivity are therefore low as well. Production at
all higher trophic levels, including both pelagic fishes and deep benthic
108
-------
o
ID
TABLE 27. INSTANTANEOUS DUMP CHARACTERISTICS FOR SELECTED SITE LOCATIONS
WITHIN THE GULF OF MEXICO
Site
Distance
Offshoreb
Description3 (km)
Shelf #120 100
Upper Continental 220
Slope #122
Continental Rise 540
#92
Variable Values Calculated for Four Hours after Dump
Initial Trapping
Depth Cloud Density Level c
(m) (g/cmc) (m)
44 1.4
2.0
1,100 1.4
2.0
2,900 1.4
2.0
bottom
bottom
600
bottom
1,300
1,400
Area
(km6)
0.01
0.01
0.15
0.44
0.54
0.62
Dilution
37
37
4,800
31,000
13,000
53,000
Thickness
(mm)
64
160
3
Site locations shown in Figure 6-2.
Distance south of Galveston, Texas.
T
Instantaneous dump volume = 3000 m.
Thickness defined as volume of solid mass/area,assuming all of the material settles to the bottom within
the 4-h area.
-------
communities, is correspondingly low. Nearshore and over the continental
shelves, phytoplankton production is higher, supporting important commercial
fisheries for both pelagic and demersal species.
Soft-bottom benthic habitats over the continental shelf of the western
Gulf of Mexico are divided into white-shrimp grounds nearshore (to depths of
22 m) and brown-shrimp grounds further offshore (depths of 22 m to at least
90 m, and perhaps to the edge of the continental shelf at about 182 m).
Each has its own characteristic fauna of both invertebrates and fishes.
Both the white shrimp (Penaeus setiferus) and the brown shrimp (P. aztecus)
are of prime commerciTl importance, and both are estuarine-"d"ependent,
utilizing shallow, brackish waters nearshore as nursery areas for their
young. A number of the demersal and pelagic fish species, especially those
of the white shrimp grounds, are similarly estuarine-dependent.
There is a series of hard-bottom banks or reefs on the outer
continental shelves of Texas and Louisiana which provide substrate for
typical reef-dwelling organisms (e.g., corals, coralline -algae, gc>rgon1anss
and the associated fish fauna). In some cases, notably for those banks in
the northern Gulf of Mexico such as the East and West Flower Garden Banks
(Figure 19), the location of the banks is such that many of the resident
species are cl imatol ogically near the limits of their existence, and for
certain species, at least partially separated from the gene pool of those
species. It has been suggested that these two facts make these communities
susceptible to collapse should the existing organisms be destroyed by any
anthropogenic factors, such as the disposal of manganese nodule processing
wastes. It has also been suggested that the northwestern Gulf of Mexico
represents a near marginal environment for many of the resident fish
species, but especially those associated with the banks and reefs of the
outer continental shelf, many of which are considered to be of tropical
faunistic affinity. The vulnerability of these unique environments should
certainly be considered in any decision of where to dispose of manganese
nodule processing wastes.
Nearshore waters of the Gulf of Mexico support important commercial
fisheries,. In particular, waters of the north central Gulf in the vicinity
of the Mississippi River delta have been described as being among the most
productive fishing grounds in the world (Thompson and Arnold 1971). Nearly
all of the commercial fish catch in this region comes from the area within a
few miles of the coast; the only currently-utilized commercial species of
note beyond 12 miles from shore are groupers and red snappers. Another
important fact to consider is that 90 percent of the U.S. commercial catch
in the Gulf of Mexico is of species spending part or all of their lives in
estuarine waters.
The most valuable Gulf of Mexico fishery is for the various shrimp
species, especially brown and white shrimp. The largest shrimp catches are
made in the northern Gulf of Mexico, between the mouth of the Mississippi
River and Freeport, Texas. Brown shrimp, the most valuable species, are
occasionally taken in depths to 91 m, but most of the catch of this species
is from waters of less than 55 m depth. White shrimp are caught in waters
of less than 27 m depth. The distribution of the various shrimp species may
110
-------
be altered by the deposition of manganese nodule processing wastes on the
continental shelf, since the species have been shown to actively select the
type of substrate they inhabit. Covering the bottom with a layer of
inorganic particulate wastes could make the bottom unsuitable for brown and
white shrimp, which are known to prefer substrates of soft mud or peat with
large amounts of decaying organic matter or vegetation.
Approximately 75 percent of the Gulf of Mexico fish catch is used for
fishmeal, oil, or other processed products. The principal catches in this
fishery are from the area east of the Mississippi River delta, however. The
largest domestic fishery in the Gulf of Mexico in terms of quantity of
landings is for menhaden, a pelagic species which is used for fishmeal, oil,
and other processed products. These fish are caught primarily within 24 km
of shore between Empire and Intracoastal City, Louisiana.
Although there are important fisheries in the Gulf of Mexico for fish
species inhabiting hard banks and reefs (e.g., snappers, groupers,
seabasses), over 87 percent of the reef fish landings are from the eastern
gulf.
There is potential for expanding and/or developing other fisheries in
the Gulf of Mexico for species currently underutilized. Commercially
exploitable stocks of tuna occur over the continental slope between the
183-m and 1,830-m depth contours and a fishery could develop for these
fishes in the future. Other species (e.g., tilefish and yellowedge grouper)
inhabit waters overlying the upper continental slope in this region, and are
believed to be present in stocks of commercially important size. There is
also potential for diversifying the shelf fisheries, now directed primarily
at shrimp, so that abundant bottomfishes (e.g., sciaenids, demersal sharks)
and shellfish (e.g., lobster, crabs, clams) could also be harvested.
SOUTHERN CALIFORNIA BIGHT
Physical Characteristics
The southern California Bight, which extends from the California-Mexico
boundary northward to Point Conception is morphologically classed as a
continental borderland (Figure 20). The southern California continental
margin consists of a very narrow shelf down to approximately the 100 m (328
ft) depth, a limited basin slope, a relatively wide borderland having a
series of basins and interbasin ridges, and a true continental slope which
extends to the deep-sea floor. Within the borderland there are more than 20
basins extending as deep as 3,000 m (9,842 ft) separated by submarine
ridges, banks, and islands which reach elevations of 500 m (1,640 ft) above
sea level (Uchupi and Emery 1963). The basins contain thick sediment fills,
whereas the higher areas consist of sedimentary, igneous, and metamorphic
rocks. Shelves around the islands and along the mainland coast resemble
typical continental shelves except for being much narrower. A number of
submarine canyons cut across the shelf, providing pathways for offshore
transport of coastal sediments. The seaward boundary of the borderland
province is distinguishable by a continental slope followed by an 8 to 20 km
(4.3 to 10.8 nmi) wide ridge at depths of 400 to 1,600 m (1,312 to 5,249
111
-------
120"W
34°N
90.70
SUBMARINE CANYONS
A. CORONADO
B. LAJOLLA
C. CARLSBAD
D. NEWPORT
E. SAN GABRIEL
ESCARPMENTS
1. CORONADO
2. SAN PEDRO
F. REDONDO
G. SANTA MONICA
H. DUME
I. MUGU
J. HUENEME
BANKS
I. CORTES
I. TANNER
REFERENCE: Uchupi and Emery, 1963.
Figure 20. Continental borderlands off southern California
showing basins, canyons, and escarpments.
112
-------
ft). Beyond the ridge the topography deepens abruptly, dropping to the
ocean basin at 3,400 to 3,800 m (1.8 to 2.1 nmi).
Along northern and central California, the coastline exhibits a general
northwest-southeast orientation. At Point Conception the coastline has an
abrupt change in orientation to an east-west alignment (gradually the coast
returns to a northwest-southeast orientation). This abrupt change in
orientation has a significant effect on the circulation pattern of the
Bight.
The general circulation pattern within the Southern California Bight is
strongly influenced by the California Current system. The California
Current is a broad [500 to 1,000 km (270 to 540 nmi)], weak (5 to 10
cm/sec), southward-flowing eastern boundary current extending from
Washington to Baja California. The water carried south by the California
Current is cooler than the waters farther offshore and is also characterized
by its low salinity, high oxygen, and high phosphate.
Below the California Current is the northward flowing California
Undercurrent. This current occurs at intermediate depths beneath the
pycnocline and seaward of the continental shelf. It is narrower
[approximately 50 km (27 nmi) in width] than the overlying southward-flowing
California Current. The Undercurrent, which is believed to have the
Equatorial Pacific water mass as its source, is characterized by high
temperature, salinity, and phosphate concentrations, but is low in dissolved
oxygen.
At Point Conception, the southward-flowing California Current no longer
flows along the coast. A northward flowing counter current or eddy forms
between the California Current and the coast, and extends from Point
Conception to San Diego. This northward flow is termed either the Southern
California Countercurrent or Eddy depending on its strength and pattern.
The northward flow is sometimes continuous around Point Conception,
particularly during winter months, when the term countercurrent rather than
eddy is commonly used to describe it. However, the relative infrequency
with which drift bottles released in the Bight are retrieved north of Point
Conception suggests that the northward flow usually contributes the majority
of its volume to recirculation in the California Current.
Representative Areas
The physical oceanographic characteristics of three southern California
Bight disposal areas are presented in the following section; a shelf/canyon
area, a borderland basin area, and finally a deep ocean basin area. The
information presented represents a synthesis of data obtained by review of a
large number of references.
Shelf/Canyon--
Shelf temperature profiles determine the local density structure much
more than salinity, and change markedly from season to season. In summer
there is a shallow warm layer which rarely exceeds 5 m (16 ft) in thickness,
113
-------
followed by a 20 m (66 ft) thermocline having a gradient of 0.25°C per
meter, and an isothermal (10°C) bottom layer. In the winter, the difference
between the mean surface and bottom temperatures is significantly reduced to
2.3°C, being only slightly colder at the bottom. Below 20 m (66 ft), the
normal winter cooling is reversed, a common feature on the west coast shelf
(Huyer 1977). The average shelf temperature is 15°C during the summer and
13.6°C during the winter.
Horizontal currents on the Southern California continental shelf are
variable, having root mean square changes in a few hours to 10 days which
typically exceed the seasonally averaged mean values. Typical speeds
observed on the nearshore shelf are from 7 to 10 cm/sec, but can vary
between 0-50 cm/sec (Hendricks 1975). During spring and summer, when the
water column is thermally stratified, surface and bottom currents may be
opposed, whereas during fall and winter, the water column is less stratified
and the flow structure is more unidirectional. Mean surface currents in all
seasons sweep to the south* At their weakest during the fall they still
exceed 2 cm/sec. Although the current structure has been found to be
similar in 60, 30, and 15 m (197, 98, and 49 ft) of water, the amplitude of
mean currents is substantially reduced at shallower stations.
Canyon flows are expected to differ from those of the nearby shelf due
to the channeling effect of the canyon walls. Higher axial current speeds
occur near the heads of submarine canyons at more frequent intervals than at
other bottom sites. It should be noted that upcanyon movement can occur as
well as downcanyon movement. Periodic turbidity currents are known to flush
accumulated bottom material down canyon axes and into basin or outer shelf
areas.
Background dissolved oxygen levels at a shelf disposal site will be
similar to those at the shoreward CalCOFI line 9 station (90.28) located in
approximately 200 m (656 ft) of water. Surface values remain fairly
constant near 8.6 mg/1 during the spring months, decreasing to 7.9 mg/1 in
the winter. At 100 m (328 ft), however, the dissolved oxygen values are
much lower, ranging from an April minimum of 2.5-3.0 ml/1 to a high in
December of 4.0 ml/1. At 200 m (656 ft), dissolved oxygen concentrations
below 2.0 ml/I have been recorded between February and August.
Borderland Basin--
Surface temperatures typically range from 19°C in August to as low as
14.5°C in January. A pronounced spring thermocline forms at 10 to 20 m (33
to 66 ft) as at shelf stations, and tends to persist through October.
Salinity, in contrast, is relatively uniform in the upper 50m (164 ft),
increasing somewhat beyond 100 m (328 ft) depth. The characteristic density
profile exhibits a strong density gradient associated with ambient
temperature, following the same pattern as temperature but in reverse
magnitude. A very strong density gradient forms in the spring, becomes
maximum [sigma-t difference is 1.0 from 10 to 30 m (33 to 98 ft) depths] in
the summer-and dissipates in the fall. Dissolved oxygen values are at a
maximum near the surface (7.8 mg/1), decrease with depth, and are relatively
constant in the upper 50 m (164 ft) throughout the year. At 100 m (328 ft)
114
-------
and greater depths, a relatively pronounced DO minimum occurs during June,
gradually returning to maximum values in December and January.
Concentrations below 2.1 mg/1 have been recorded at depths beyond 300m
(984 ft).
Dynamic topography contours for surface geostrophic flows relative to
flows at 500m (1,640 ft) (Wyllie 1966) for a mid-Bight location indicate
south to southeast flows for February through June, with northerly flows
from July to January. Flows at a 200 m (656 ft) depth relative to those at
500 m (1,640 ft) appear to be northward throughout the year except during
March and April, when calculated flows become very low. Although monthly
mean charts serve only as a guideline, the trend of the southward-flowing
California Current moving inshore during April-May and eliminating the
Southern California Countercurrent at the surface is evident, and may happen
briefly even at the 200 m (656 ft) level. Outside of this period, however,
flows can be expected to be northward. Dynamic topography charts indicate
approximate current speeds of 0-10 cm/sec at the surface, and less than 5
cm/sec at 200 m (656 ft).
Deep Ocean--
Surface temperatures vary from 17°C during August through October to a
low of 14.5°C between January and June. At 100 m (328 ft) the temperature
variation is slight, remaining at approximately 10.5°C. Although a
thermocline is present, it is far less pronounced than at nearshore
stations. Surface salinity varies little, remaining at 33.4 ppt. An
increase of 0.1 ppt is apparent at depths of 100 to 200 m (328 to 656 ft) in
October and November. The density profiles appear to follow the water
temperature pattern in the upper 50 m (164 ft), and seem to be dependent
primarily on salinity variations in waters below this depth. The maximum
density gradient occurs in September and October. Seasonal density
variation at depths below 50 m (164 ft) is small, amounting to approximately
0.2 sigma-t units or less. Dissolved oxygen in the surface waters remains
seasonally constant at 7.8 mg/1 and decreases approximately 2.9 mg/1 per 100
m (328 ft) of depth from 50 to 200 m (164 to 656 ft). There is evidence of
slight maxima in May and minima in November. However, the annual range at a
given depth is approximately only 1.4 mg/1 below 75 m (246 ft) deep. At 200
m (656 ft), a value of 3.6 mg/1 has been reported. Values as low as 2.1
mg/1 occur at depths below 300 m (984 ft). Calculated geostrophic flows at
the surface relative to a 500 m (1,640 ft) depth appear to be between 2 and
15 cm/year to the southwest throughout the year. Maximum currents probably
occur in the June/July and November/December periods (Wyllie 1966).
Currents at 200 m (656 ft) relative to 500 m (1,640 ft) appear to be much
weaker, being between 0 and 3 to 4 cm/sec. For much of the year (e.g.,
August to December) the flow pattern appears to be poorly defined.
Fate of Material
The fate of instantaneously dumped material is considered at CalCOFI
Stations 90.28, 90.45, and 90.70 (Figure 20). The 4 hour fate computations
using the methods described in Chapter 3 are summarized in Table 28. None
of the CalCOFI density profiles are sufficiently strong to trap the cloud at
115
-------
TABLE 28. INSTANTANEOUS DUMP CHARACTERISTICS FOR SELECTED SITE LOCATIONS
IN THE SOUTHERN CALIFORNIA BIGHT
Description3
Cal COFI 90.82
Cal COFI 90.45
Cal COFI 90.70
Site
Distance
Offshore5
(km)
5
126
300
Initial
Depth Cloud Density
(m) (g/cmc)
200 1.4
2.0
900 1.4
2.0
1.4
2.0
>3,000 1.4
2.0
1.4
2.0
Variable
Trapping
Level0
(m)
bottom
bottom
200e
200e
900f
900f
200e
200e
3,000];
3,000T
Values Calculated
Area
(kmb)
0.03
0.03
0.03
0.03
0.3
0.3
0.03
0,03
2
2
for Four Hours
Dilution
400
400
400
400
1,400
1,400
400
400
320,000
320,000
after Dump
Thickness
(mm)
15
38
aSite locations shown on Figure 6-13.
^Distances measured on line to SW from Dana Pt.
clnitial dump volume = 3,000 m^.
^Thickness defined as volume of solid mass/area, assuming all of the material settles to the bottom within
the 4-h area.
eTrapping level is greater than this value.
fTrapping level is less than or equal to this value.
-------
depths less than 200 m, yet none of the profiles report densities at depths
greater than 200 m making it impossible to determine whether the cloud
impacts the bottom. Hence in Table 28 the trapping level for sites 90.45
and 90.70 are chosen equal to 200 m and the water depth. These two depths
bracket the possible area and dilution values.
The maximum slope from the shoreline to the 200 m contour shown in
Figure 20 is roughly 3 degrees. This slope may be sufficiently steep to
allow discharging of material heavier than seawater from an outfall.
However, careful experiments would be necessary to establish the adequacy of
a nearshore site. In the southern California Bight, the ideal location for
an outfall site is at the head of a submarine canyon. Very steep canyon
slopes insure predominantly downward transport of discharged material. Even
though upcanyon transport occasionally exists, no significant upward
transport of material above the depth of the outfall is expected based on
the behavior of sludge discharged from the Hyperion sludge outfall.
Marine Biological Characteristics
Although phytopl ankton production is generally not nutrient limited
waters of the California Current beyond the continental shelf off southern
California, annual primary production is nevertheless low relative to areas
over the shelf and nearshore. Consequently, production at all higher
trophic levels, including both pelagic fishes and deep benthic communities,
is also low. An additional factor which reduces the amount of organic
matter reaching deep benthic communities in this area is that terrigenous
sediments from southern California are currently being deposited in the deep
basins of the continental borderland, and hence are not transported into the
deep sea by turbidity currents, as is the case in other areas (e.g.,
offshore of the Pacific Northwest coast).
There is typically an onshore-offshore gradient in both phytopl ankton
standing stocks and primary productivity off southern California, such that
the highest stocks and highest production occur nearshore. Production
nearshore is enhanced seasonally by coastal upwelling, since the
phytoplankton nearshore are at other times limited by the availability of
fixed nitrogen.
The complex topography of the California continental borderland
represents a variety of habitats for benthic organisms. Some of the deep
basins of the continental borderland have a depauperate benthic fauna due to
their low dissolved oxygen concentrations, which are caused by reduced water
exchange and the decay of organic matter within the basins. Various shallow
benthic habitats also exist on the continental borderland of southern
California. Several hard-bottom banks (e.g., Cortes and Tanner Banks;
cf. Figure 20) are unique in that they provide shallow water habitats at
great distance from shore (approximately 180 km). Also present on the
continental borderland are a number of offshore islands which are surrounded
by both hard and soft bottom substrates for benthic community development.
These islands also represent important habitat for various pinnipeds,
including California sea lions, Stellar sea lions, and northern elephant
seals.
117
-------
Important nearshore habitats which could be particularly vulnerable to
impacts of the disposal of manganese nodule processing wastes include rocky
intertidal and subtidal habitats, kelp beds, and submarine canyons.
Major fisheries in the Southern California Bight are focused on pelagic
species, such as northern anchovies, jack mackerel, and tunas, rather than
demersal species. Trawl fisheries, which are of greatest importance in
other coastal areas, are not extensive in southern California, due both to
the small area of the continental shelf and to certain regulatory
limitations. The small southern California trawl fishery, which catches
primarily rockfishes and flatfishes, is largely limited to the Santa Barbara
Channel.
Tuna fisheries account for a substantial portion of the landings in
southern California. While yellowfin and skipjack tunas are caught
primarily off the coasts of Central and South America, both bluefin tuna and
albacore are seasonal migrants into southern California waters, and an
offshore fishery there is directed at these species.
A significant oil and fish meal reduction fishery is centered in the
channel region extending between Santa Barbara-Santa Cruz Island and Santa
Catalina-Dana Point. This fishery, directed primarily at northern anchovy,
also takes jack mackerel, Pacific mackerel, bonito, bluefin tuna, and squid.
Both northern anchovy and jack mackerel are schooling species which are
particularly abundant near the surface in waters overlying the deep basins
of the continental borderland. Adult jack mackerel are abundant over rocky
banks at depths of 9-55 m, around the rocky perimeters of offshore islands,
and in rocky coastal areas associated with kelp beds. Over 90 percent of
the catch of jack mackerel is from the vicinity of Santa Catalina and San
Clemente Islands and on Cortes Bank.
Other lesser fisheries in southern California include: a developing
fishery for squid within 4.8 km of shore, both on the mainland coast and in
the vicinity of the channel islands; a spiny lobster fishery in rocky
coastal areas; an abalone fishery centered in the vicinity of kelp beds
around the channel islands and near Santa Barbara; and a developing pot
fishery for sablefish. Fisheries with considerable potential for future
expansion include: the squid fishery; the oil and fish meal reduction
fishery for northern anchovies and jack mackerel (especially if other
markets could be developed); and fisheries for currently underutilized
groundfish species such as sharks, skates, and rays.
Certain species of commercial importance have demersal eggs and hence
are potentially vulnerable to burial under manganese nodule processing
wastes. Squid, for instance, attach their eggs to sandy substrates in
semi-protected bays. California halibut also spawn demersal eggs.
Selection of a disposal site for these wastes should consider avoidance of
spawning areas utilized by such species.
While there is currently a developing fishery for Pacific hake in the
Pacific Northwest, this species is not fished commercially in southern
118
-------
California. Pacific hake undertake extensive seasonal migrations, however,
and it is known that the hake caught off the Pacific Northwest were spawned
at depths of 183-503 m over the California continental slope. During the
spring and summer, adult hake move northward and inshore, where they become
subject to the fishery over the Pacific Northwest continental shelf.
PACIFIC NORTHWEST REGION
Physical Characteristics
The northwest offshore region discussed in this section extends from
Cape Mendocino in northern California to Cape Flattery in Washington. The
continental shelf in this region is generally narrower, steeper, and has
greater depths than average values for other continental shelves of the
world. Significant features of the shelf are the submarine canyons which
traverse the seaward edge of the shelf, and the banks which rise abruptly
60-73 m (197-239 ft) near the shelf edge (Figure 21).
The prominent feature of Pacific Northwest shelf circulation is a
southward coastal jet during the upwelling season (Mickey 1979b). In
spring, the center of the southward flow moves from a summer position of 15
km (8 nmi) offshore to within 10 km (5.4 nmi) of the coast. The width of
the flow increases at this time, extending out over the continental slope
(Huyer et al., 1978). Over the inner shelf, the currents are apparently
much weaker than at mid-shelf. Surface currents over the outer shelf are
generally believed to be southward. Beyond the shelf, geostrophic
calculations indicate a mean southward flow which is weaker than at
mid-shelf.
At depths of 200 to 300 m (656 to 984 ft) there is a northward
undercurrent (Favorite et al., 1976), whose presence has been verified off
Oregon in spring and early summer (Huyer and Smith 1976) and off Washington
in late summer and early fall (Cannon et al., 1975; Reed and Hal pern 1976).
Between July and September, the northward flowing jet over the Washington
continental slope has been observed to be 20 km (10.8 nmi) wide and 200 m
(656 ft) thick, (excluding flow components below 5 cm/sec). A maximum core
speed of 16 cm/sec has been measured at a depth of 192 m (630 ft) in 600 m
(1,968 ft) of water (Hickey 1979b). Below 60 m (197 ft), slower northward
flow was observed, on the average, over a 6-week period (July-September) as
far as 80 km (43.1 nmi) offshore, across the slope, and over the entire
shelf.
Representative Disposal Site Characteristics
Typical physical oceanographic conditions at shelf, slope, and basin
sites off the Oregon coast are presented in this section. Although the
salinity, temperature, and density data are isolated measurements, they do
represent conditions expected during the winter and summer periods. The
current profiles are mean currents over the winter and summer periods.
Further offshore, over the lower slope and deep-ocean basin where current
measurements are not available, calculated geostrophic flows are presented.
119
-------
I29°W
125°
I2OC
Eel Canyon
Mendocino Canyon
P Cope Mendocino
«&../.
49°N
-U5°
40°
REFERENCE: McManus, 1964; Byrne, 1963a.
Figure 21. Relative positions of major submarine banks and
canyons off Northwest coast.
120
-------
Shelf—
The pronounced temperature gradient which is apparent in the upper 20 m
(66 ft) in summer becomes less intense in winter extending down to 40 m (131
ft) depth. Beyond this depth, temperature variations are slight, decreasing
to 6° C in deeper waters. Density data indicate a significant dependence on
salinity in both the winter when the temperature gradient is small, and
during the summer when a strong thermocline is present. Longshore velocity
components are much greater than onshore components, and near surface flows
are predominantly southward in both summer and winter periods. Movement
below 75 m (246 ft) is northward during both seasons.
The distribution of dissolved oxygen (DO) in northwest coastal waters
is complicated due to upwelling, freshwater discharges, entrainment of deep
water, and wave action (Stephansson and Richards, 1964). Biological
activity nearshore is also more intense and more variable than farther
offshore. Maximum surface DO values of 10.0 to 10.7 mg/1 occur nearshore
between June and July. The generally high surface values exceed levels
expected for colder upwelled waters in atmospheric equilibrium, and are
attributable to high photosynthetic production rates.
Upper Slope—
A strong thermocline and halocline can persist during the summer in the
upper 10 m (33 ft). In winter, smaller gradients can occur and two
stratification levels appear at approximately 10 and 60 m (33 and 179 ft),
the upper one being due to cool low-salinity water very near the surface.
Upper slope currents are strongly southward in summer down to 100 m (328
ft), beyond which a slow northward current occurs. Average currents down to
150 m (492 ft) persisted in an onshore direction during a 30-day measurement
period. In winter (January-April), the mean longshore current magnitudes
are very low, with some southward movement down to 100 m (328 ft) and
northward flow beyond to the sea floor. Mid-slope temperature and salinity
profiles appear similar to those on the upper-slope during both the summer
and winter periods. Southward currents persist from 50-200 m (164-656 ft),
while movement in the onshore direction is very slight.
Lower-Slope and Upper-Basin—
In lieu of measured currents in the offshore area, calculated
geostrophic flow profiles are used. Summer surface currents at 65 km (35
nmi) offshore are southward in summer, decreasing from approximately 6
cm/sec to no current at a depth of 150 m (492 ft). In an adjacent area 10
km (5.4 nmi) further offshore, near-surface southward currents of 5 cm/sec
decrease to negligible speed at 50 m (164 ft).
Beyond the continental shelf, DO values remain relatively constant in
the upper mixed layer at near 9.0 mg/1. DO concentrations increase to
maxima of 9.3 to 9.6 mg/1 between March and May. As the temperature further
increases in summer, lower DO solubility results in decreased surface
concentrations of approximately 8.2 mg/1 in the upper 10-20 m. A subsurface
maximum at depths of 20 to 50 m persists at the previously established
winter concentration of 9.6 mg/1, however.
121
-------
Fate of Materials
The fate of instantaneously dumped material is considered at four
offshore regimes characterized by water depth. Each region has two
stations, one having winter density profiles, the other summer density
profiles. Each station is shown in Figure 22. The 4-hour fate computations
using the methods described in Chapter 3 are summarized in Table 29. As can
be seen from these results, the density stratification is not sufficiently
strong to trap the 3,000-m3 dump except at the continental slope station
during the summer. The area of impact after 4 hours does not exceed 0.11
km^ except at the slope station. The dilutions are modest at the nearshore
stations and much larger in deeper water. In this region the surface
currents are to the south and below 100 m the currents are on the order of 1
cm/sec to the north. Hence, all of the instantaneous dump clouds are
advected slowly to the north, while continuous surface discharges are
carried to the south until the particles fall below 100 m depth.
The maximum slope from the shoreline to the 50 m contour shown in
Figure 22 is roughly 1 degree. The slope from the 50 to 100 m contour is
even less. Location of an outfall a reasonable distance from shore is
unlikely to allow adequate dispersion of negatively buoyant waste material.
However, a detailed examination of the nearshore bathymetry may reveal
acceptable sites.
Marine Biological Characteristics
Oceanic primary production far beyond the continental shelf of the
Pacific Northwest is relatively low due to low light levels in winter and
nutrient limitation in summer. Production at higher trophic levels,
including both pelagic fishes and deep benthic communities, is
correspondingly low. Nearshore and over the continental shelf,
phytoplankton production is higher, due in large part to seasonal coastal
upwelling, which typically occurs duing spring and summer. The higher
primary production over the shelf supports important commercial fisheries
for both pelagic and demersal species.
In deep benthic habitats at the base of the continental slope, the
abundance of benthic organisms is apparently correlated with the magnitude
of the input of organic detritus via turbidity currents. Consequently, much
larger benthic populations may exist in areas receiving frequent turbidity
current deposits (e.g., Cascadia Channel) than in other nearby areas where
turbidity currents are of minor significance (e.g., Cascadia Abyssal Plain).
On the continental shelf of the Pacific Northwest, the abundance of
macroepibenthic organisms is largely determined by the type of substrate.
Within 20 km of the Oregon coast, for instance, the bottom is essentially
100 percent sand, reflecting the high wave energy in this environment during
winter storms. This sand has a very low organic carbon content, and as a
consequence, both the numerical abundance and biomass of macroepibenthic
organisms is low there. With increasing distance offshore, however, the
sediment grain size decreases and the organic carbon content increases (as a
122
-------
125" 30'
125" W
124* 30'
Figure 22. Stations used for the estimation of instantaneous
dump characteristics in the Pacific Northwest.
123
-------
TABLE 29. INSTANTANEOUS DUMP CHARACTERISTICS FOR PACIFIC NORTHWEST
SELECTED SITE LOCATIONS OFFSHORE OF THE COAST
Site
Description6 Distance
(S = Summer Offshore"
W = Winter) (km)
Shelf:
Carnation (S) 11
Sunflower (W) 12
Upper Slope:
Edelweis (S) 28
8D (W) 29
Mid Slope:
Forsythia (S) 47
19D (W) 57
Slope:
Gladiolus (S) 83
16D (W) 96
Variable Values Calculated for Four Hours
Initial
Depth Cloud Densi
(m) (g/cmc)
99 1.4
2.0
97 1.4
2.0
196 1.4
2.0
218 1.4
2.0
492 1.4
2.0
435 1.4
2.0
1,412 1.4
2.0
1,356 1.4
2.0
Trapping
ty Level0
(m)
bottom
bottom
bottom
bottom
bottom
bottom
bottom
bottom
bottom
bottom
bottom
bottom
611
1,124
bottom
bottom
Area
(kmb)
0.02
0.02
0.02
0.02
0.03
0.03
0.04
0.04
0.11
0.11
0.10
0.10
0.16
0.43
0.59
0.59
Dilution
120
120
110
110
400
400
500
500
3,100
3,100
2,400
2,400
5,300
29,000
50,000
50,000
after Dump
Thickness
(mm)
2
81
33
82
15
38
13
33
4
11
5
13
1
2
aSite locations shown on Figure 6-34.
b
Distance measured from site due east to coastline.
c 3
Initial dump volume = 3,000 m .
^Thickness defined as volume of solid mass/area,assuming all of the material settles to the bottom within
-------
result of the smaller particle size and of the higher primary production in
the waters overlying the outer continental shelf). As a consequence, both
the numerical density and the biomass of macroepibenthic organisms increase
with distance offshore to depths of 200 m. The biomass of these organisms
at 200 m depth has been estimated to be 73 times higher than the biomass at
50 m depth. The numerical abundance of benthic infauna exhibits a bimodal
distribution, with high abundances nearshore and near the shelf break.
Filter feeders dominate nearshore, while deposit feeders are more abundant
near the shelf break. One result of the higher production in the overlying
waters and of the higher abundance, of macroepibenthic organisms near the
shelf break is that demersal fishes are most abundant on the outer
continental shelf and upper continental slope (depths of 91-411 m).
Rocky intertidal and subtidal environments nearshore support diverse
benthic communities. These areas also provide important habitat for both
Stellar sea lions and sea otters.
Commercial fisheries are of great economic importance in Washington and
Oregon. Both pelagic and demersal species are heavily utilized. Although
the continental shelf is relatively narrow, demersal trawling is not limited
to the shelf but extends offshore to depths of at least 1,280 m. Demersal
trawls are utilized to capture a wide variety of fishes including
flatfishes, rockfishes, and lingcod. Midwater trawls are utilized to
harvest Pacific hake, widow rockfish, and shortbelly rockfish. Wide-ranging
epipelagic fishes, such as albacore and several species of salmon (notably
chinook and coho), are caught by trolling.
Certain Pacific Northwest fisheries are dependent on seasonal
migrations of the fish. Albacore, for instance, only enter the offshore
waters of the Pacific Northwest (typically 80-241 km from shore, and
occasionally to 482 km from shore) when the surface waters have warmed
appreciably (e.g., late summer and early fall). Albacore are then subject
to a brief, but intensive fishery. Pacific hake migrate to the shelf waters
of the Pacific Northwest for feeding during spring and summer. During fall
and winter, they are found over the continental slope off California. The
only commercial fishery for this species occurs in the Pacific Northwest.
The salmon troll fishery, conducted primarily within 19 km of the shore, is
also subject to seasonal variations in abundance because the salmon
undertake spawning migrations to the freshwater rivers and streams of the
Pacific Northwest.
Two invertebrate species support important commercial fisheries in the
Pacific Northwest. Dungeness crabs are caught in pots at depths less than
91 m, primarily in sand or mud bottom areas. Pink shrimp are caught in
trawls, primarily in depths of 91-183 m, over bottoms of green mud or a
mixture of mud and sand. They are occasionally caught at depths as shallow
as 64 m or as deep as 302 m.
Currently-underutilized fish species could support expanded fisheries
in the future in the Pacific Northwest. Demersal species which could be
caught in greater numbers than at present include certain sharks, skates,
and flatfishes. Pacific hake catches could also support expanded fisheries
125
-------
in coming years. Among the pelagic fishes, there is potential for
increasing the catch of Pacific herring (especially if they could be fished
in the open ocean), northern anchovies, Pacific mackerel, and pomfret.
Squid could also be caught in commercial quantities in this area.
Commercial species of the Pacific Northwest exhibit such a great
diversity of life cycles and reproductive strategies that it is difficult to
make generalizations. Fishes which reproduce in the area may be either
oviparous (egg laying; e.g., Pacific cod) or ovoviviparous (bearing live
young; e.g., certain rockfishes). Fish eggs may be pelagic (e.g.,
sablefish), semipelagic (initially demersal, subsequently pelagic; e.g.,
Pacific halibut), demersal without parental care (e.g., Pacific cod), or
demersal with parental care (e.g., lingcod). Eggs of commercially-important
invertebrates may also be pelagic (e.g., crabs, shrimp) or demersal (e.g.,
squid). While a number of commercially-important species leave the marine
waters of the Pacific Northwest to spawn (e.g., albacore spawn in the warmer
waters of the central Pacific, Pacific hake spawn off California, Pacific
herring spawn in protected bays and estuaries, salmon migrate to freshwater
rivers and streams) others spawn in the marine waters of the region (e.g.,
Pacific cod, Pacific halibut, lingcod).
HAWAII
Physical Characteristics
Previous studies by Jenkins et al. (1981) have identified the island of
Hawaii as a potential location for a manganese nodule processing plant and
noted that one ocean mining, group has publicly expressed interest in this
site. For this reason, the physical and biological characterization of this
region is focused specifically on the waters around the island of Hawaii and
especially the eastern or windward site.
Bathymetry--
Figure 23 presents the bathymetric contours in the vicinity of Puna
Canyon. The morphology of the adjacent Puna Ridge was surveyed using a
submersible by Fornari et al. (1979). The ridge is a submarine continuation
of the East Rift Zone of Kilauea volcano, and represents a principal locus
of submarine volcanic activity and a major outbuilding site for Kilauea.
The micromorphology consists of fresh lava pillows and cylinders with a lack
of interstitial sediments and benthic fauna.
Circulation Patterns—
The primary factors which influence current patterns in Hawaiian waters
are the West Wind Drift, tidal motions, and an anticyclonic gyre northeast
of the islands. Currents generally show strong tidal variations, frequently
including direction reversals over a tidal cycle, but are modified locally
by winds, internal wave motions, and other factors.
In examining data available near proposed dredge spoil disposal sites
off of Hilo (Figure 24), it became apparent that previous oceanographic
126
-------
156° 155°
0
I
155°
I
I
I
50
I NAUTICAL MILES
I I I I I I
KILOMETERS
0 50
CONTOURS IN THOUSANDS OF FEET
Figure 23. Bathymetry of the Puna Canyon,
18°
127
-------
155°00'
154°50'
— 19°42'
J NAUTICAL MILES
KILOMETERS
I
8
REFERENCE: EPA 1980C
Figure 24. Proposed and alternative dredged material
disposal sites.
128
-------
measurements were made either within Hi To Bay or much farther offshore in
waters exceeding 3,000 m (10,000 ft) (Neighbor Island Consultants 1977). A
very limited amount of current data is available for dredge spoil disposal
sites 9 and 9B near Hilo Bay. At the Inner Hilo site 9 which is in 340 m
(1,115 ft) of water, two days of surface current measurements (drogue
movements) indicated northwesterly flows at between 15 and 36 cm/sec. Upper
subsurface currents were highly variable with some tidal correlation.
Deeper currents decreased in magnitude but became more uniform in direction,
remaining between 338° and 20° of magnetic north. Surface currents had 180°
reversals in direction. At 15 m (50 ft), currents ranged from 15 to 57
cm/sec, decreasing toward the bottom to between 0 and 15 cm/sec. At site 98
(Outer Hilo) which is in 329 m (1,080 ft) of water, surface drogue
measurements indicated a moderate west-southwesterly flow. Subsurface
currents of less than 26 cm/sec were generally oriented toward the
northwest. A tidal influence was evident on all records. The EIS for
Dredged Material Disposal Sites Designation (U.S. Environmental Protection
Agency 1980c) indicates that current depths of these sites were 29, 19, 16,
and 11 cm/sec for meters at 15, 45, 183, and 340 m, respectively, with
deeper flows being towards the north.
Current measurements have also been made at nearby University of Hawaii
Station 212 off Alia Point to the north of Hilo in 210 m of water (Wyrtki et
al., 1969). August 3 through 15 recordings for a meter at 30m (98 ft)
depth indicated strong easterly (107° true) average current speeds of 32.7
cm/sec, with weak tidal currents superimposed.
' In January, the surface water temperatures were 25° C, decreasing to
22° C at 152 m (500 ft). At this point, a relatively sharp thermocline
occurred down to 243 m (800 ft). Beyond this depth, temperatures continued
to decrease, reaching 9° C at 426 m (1,400 ft).
Currents nearshore appear to be southward and can reportedly be as high
as 100 cm/sec. Deeper than 30 m (100 ft), currents decrease significantly,
becoming negligible. Offshore, from 15 to 35 km, northward surface currents
are weaker, being 25.7 cm/sec or less. Subsurface currents decrease quickly
as a function of depth, and tend to flow to the south.
Currents along the canyon axis at 426 m (1,400 ft) depth range from 0
to 13 cm/sec, and directionally are a function of tides, being upcanyon on a
rising tide and downcanyon on a falling tide. Bottom visibility is very
high due to the lack of any sediment sources nearby, the closest drainage
being 50 km (28 mi) away.
Representative Area
For the purpose of this project, the Puna Canyon area is discussed in
view of its proximity to an existing dredged material disposal site (9B).
It should be noted that site 9A in 2,103 m (6,900 ft) of water (Figure 24)
was relocated to site 9B due to intense commercial fishing at 9A (Neighbor
Island Consultants 1977).
129
-------
Fate of Material
The fate of instantaneously dumped material is considered at Site 9
which is shown in Figure 24. The 4-hour fate computations using the methods
described in Chapter 3 are summarized in Table 30. These results show that
the cloud impacts the bottom. Due to the steep bottom slope, the cloud is
likely to travel down Puna Canyon into much deeper water, and the 4-hour
trapping level may be much greater than that shown in the table. Similarly,
if an outfall discharging material more dense than seawater were located
near the head of Puna Canyon, a turbidity plume would carry most, if not
all, of the material down the canyon into very deep water.
Marine Biological Characteristics
Due to the strong vertical stratification of the water column in open
ocean environments of the tropical Pacific, the supply of nutrients to the
epipelagic zone is limited, and phytopl ankton primary production there is
very low. As a consequence, production at all higher trophic levels,
including both pelagic fishes and deep benthic communities, is also very
low. Deep benthic organisms are in particularly low abundance in open ocean
areas of the tropical Pacific because they are far removed from terrigenous
sediment sources with their associated organic detritus, the productivity of
the overlying waters is very low, and the benthtc communities are separated
from the epipelagic communities by a deep water column. Ambient
sedimentation rates are very slow, and hence it is likely that benthic
organisms in these habita-ts are ill-adapted to significant increases in
these rates, which could accompany disposal of manganese nodule processing
wastes in the open ocean.
Phytoplankton primary productivity near the Hawaiian islands is
enhanced due to an "island mass effect" which appears to be associated with
increased turbulence and vertical mixing in the channels between the
islands. Primary production is also elevated near the islands due to the
contribution of benthic algae, especially the coralline algae which are the
primary reef-building organisms in this area.
Coral reefs are well developed along the leeward or Kona (western)
coast of the island of Hawaii, but there is little coral growth on the
windward (eastern) side of the island, due to the exposure of this coast to
waves driven by the trade winds. The only fringing reef on the island of
Hawaii is located on the northwestern side of the island. Coral growth is
less vigorous north of Keahole Point on the Kona coast of Hawaii, perhaps
due to the finer sediments and higher turbidity found in this area. This
may be a natural phenonemon related to the protected nature of this coast
with respect to the prevailing wind and waves.
The amount of wave exposure has a direct relationship with both the
amount and type of coral growth in nearshore environments on the island of
Hawaii. The Kona coast has a rich and varied benthic fauna, both
intertidally and subtidally, while there are fewer benthic organisms on the
windward coast. Consequently, even the type of fishes inhabiting a
nearshore area can be a function of the amount of wave exposure.
130
-------
TABLE 30. INSTANTANEOUS DUMP CHARACTERISTICS FOR SITE LOCATIONS
OFFSHORE OF THE ISLAND OF HAWAII
Description3
Site 9
Site
Distance
Offshoreb
(km)
9
Variable Values Calculated for Four Hours after Dump
Initial Trapping
Depth Cloud Density Level0
(m) (g/cm°) (m)
329 1.4 bottom
2.0 bottom
Area
(km6)
0.06
0.06
H
Thickness
Dilution (mm)
1,250 8
1,250 19
aSite location shown on Figure 6-53.
bDistance measured from nearest point of land.
c
Instantaneous dump volume = 3000 rrp.
dThickness defined as volume of solid mass/area, assuming all of the material settles to the bottom within
the 4-h area.
-------
Coral reef communities are particularly susceptible to environmental
perturbations associated with the introduction of sediments to the nearshore
environment. High turbidity may limit algal growth or interfere with
filter-feeding organisms. Deposited sediment may bury the hard substrate
needed for attachment or cause abrasion of soft benthic organisms. For
these reasons, it is less desirable to dispose of fine particulate wastes
(such as manganese nodule processing wastes) in areas where coral reefs are
present than in areas where they are absent.
Due to the narrowness of the insular shelf around Hawaii, there is not
an extensive shelf community beyond the reefs, but rather the sea floor
increases in depth rapidly with increasing distance from shore.
One seasonal inhabitant of Hawaiian nearshore environments deserves
special attention. Humpback whales range over much of the North Pacific
Ocean but overwinter near the Hawaiian islands, especially along the
northwestern and southern coasts of the island of Hawaii. The overwintering
grounds of this endangered species are receiving consideration as a national
marine sanctuary.
Hawaiian fisheries are primarily conducted within 32 km of the coast.
On the island of Hawaii, both Hilo and Kona are important commercial fishing
centers. Kona is an important sport fishing port as well. Because Kona is
located on the leeward side of the island, its fisheries are more
diversified and its landings are greater than at Hilo, where rough waters
limit fishing activity. Tuna fisheries are the most important fisheries
around the island of Hawaii, followed by the fisheries for limpets, wahoo,
scads, and blue marlin. Due to the narrow insular shelf, trawls are little
used in Hawaiian fisheries; handlines and trolling are the major fishing
methods.
Yellowfin tuna are caught in a night handline fishery between 24-80 km
from shore off both Hilo and Kona. Other species caught in this fishery
include albacore, bigeye tuna, several billfish species, and dolphin
(mahimahi). All of these species, as well as wahoo, are taken in the
daytime handline, surface troll, and longline fisheries within 32 km of the
coast.
In areas having rocky bottoms, with dropoffs, pinnacles, and
depressions, bottomfish species such as snappers, amberjack, and jack
crevalle are caught on deep-sea handlines. There is also a midwater
handline and net fishery for scads within 3.2 km of the coast in depths of
27-107 m.
In sandy bottom areas at depths of 27-91 m off the Kona coast of
Hawaii, there is a small commercial fishery for crabs. Precious corals,
which grow only at depths of 100-400 m, also support a minor commercial
industry on the island of Hawaii. An important bed of precious corals
occurs off Keahole Point on the Kona coast; other areas likely have such
beds but have yet to be explored.
132
-------
Within 32 km of shore around the island of Hawaii, most of the pelagic
fish stocks are already heavily exploited and there is probably little room
for expansion of existing fisheries. The tuna fisheries and fisheries for
billfishes could conceivably be extended into waters farther from shore in
the future. Presently underutilized species in these waters include sharks
and shrimp. The development of a fishery for sharks is subject to market
acceptance, but could be substantial. Shrimp are believed to be abundant at
depths of 274-640 m over a variety of substrates, and it is possible that a
fishery could develop in the future.
It is worth noting that the most important commercial species in the
Hawaiian fisheries are wide-ranging pelagic fishes (e.g., tunas, marlins,
dolphin, etc.) which are not limited to the waters around the islands.
Thus, they would be less susceptible to adverse effects of waste disposal
than would local demersal species which support important fisheries in other
geographic areas (e.g., the Pacific Northwest).
SUMMARY - MARINE BIOLOGICAL CHARACTERISTICS
The marine biological environments of the four representative disposal
areas (Hawaii, Pacific Northwest, Southern California, and Gulf of Mexico)
all have several features in common and a number of important differences.
In all four areas, the lowest primary production, and hence the lowest
production at higher trophic levels, occurs in open ocean environments far
beyond the shelf. In all of the areas, the benthic biomass in the deep sea
is low as a result of the physical isolation of these environments and the
low productivity of the overlying waters. The only fisheries of note in the
open ocean portions of these four areas are for wide-ranging pelagic
species, and hence the open-ocean fisheries are not limited to restricted
geographical areas.
In each representative disposal area, primary productivity is enhanced
nearshore, although by different mechanisms. In Hawaii, phytoplankton
primary productivity is enhanced near the islands by the so-called "island
mass effect," and there is also an important contribution to overall
community productivity by benthic algae. In the Pacific Northwest and off
southern California, nearshore productivity is increased by seasonal coastal
upwelling. Primary productivity over the shelf in the northwestern Gulf of
Mexico is apparently higher due to the river discharge along the coasts of
Louisiana and Texas.
Coral reef communities, which are particularly susceptible to adverse
impacts of the marine disposal of fine particulate wastes, are found near
shore in the Hawaiian islands and near the shelf break on several banks in
the northwestern Gulf of Mexico. On the island of Hawaii, extensive coral
growth is only found on the leeward, or Kona coast. High wave energy
restricts the growth of coral on the windward coast. Coral reef communities
of the northwestern Gulf of Mexico are limited to hard banks far from shore
(e.g., the East and West Flower Garden Banks; cf. Figure 19). These
isolated habitats are believed to be cl imatol ogical ly near the limits of
existence for many of the resident species, and therefore especially
vulnerable to anthropogenic sources of stress.
133
-------
Hard bottom banks are also found far offshore ( 180 km) from the
Southern California Coast (e.g., Cortes and Tanner Banks; cf. Figure 20).
While they do not support coral reef communities, these banks do provide
substrate for the development of unique, shallow water benthic habitats.
Their communities are also susceptible to impacts from anthropogenic
stresses.
Due to the narrowness of the insular shelf off the island of Hawaii and
the precipitous increase in depth with distance offshore, benthic organisms
are most abundant nearshore, especially in the vicinity of coral reefs along
the Kona coast. Macrobenthic organisms are also found in abundance over the
inner continental shelf of the northwestern Gulf of Mexico, especially on
the white and brown shrimp grounds at depths less than 91 m. In contrast,
however, macroepibenthic organisms are relatively rare on the inner
continental shelf of the Pacific Northwest. Due to strong winter storms in
this region, the sediments out to approximately 20 km from shore are 100
percent sand size particles, with a low organic content which apparently
does not support high organism abundance. Beyond 20 km from shore, benthic
biomass increases with increasing distance from shore, reaching a maximum
near the shelf break, but remaining high even over the upper continental
slope. The complex topography of the California borderland does not lend
itself to generalizations about across-shelf gradients in benthic biomass.
Benthic biomass is high on shallow banks and around the channel islands, but
may be depauperate in the deep basins of the borderland due to low dissolved
oxygen concentrations.
Important commercial fisheries are conducted in each of the
representative disposal areas. In open ocean waters of the tropical Pacific
Ocean, the only fishery of note is for wide-ranging tuna species. The
primary Hawaiian fisheries are conducted nearshore, and are directed at
pelagic species such as tuna, marl in, and other billfishes. Some demersal
species are caught on handlines, especially in areas with rocky bottoms, but
trawls are not regularly utilized. Important pelagic fisheries in the
Pacific Northwest are directed at salmon within 19 km of shore year-round,
and at albacore in the open ocean during some summers. Demersal species are
caught in large quantities by trawls, especially over the outer continental
shelf and upper slope. Developing fisheries in the Pacific Northwest
include those for Pacific hake, widow rockfish, and pink shrimp over the
outer continental shelf. In southern California, the primary fisheries are
for pelagic species, such as tuna, northern anchovies, and jack mackerel.
Demersal fisheries are very limited in southern California due to the narrow
area of the continental shelf and to some regulatory limitations. Aba!one,
spiny lobster, and kelp are harvested in rocky subtidal habitats near shore
which could be adversely affected if they received significant inputs of
fine particulate wates. In the Gulf of Mexico, fisheries of importance
include those for white and brown shrimp, primarily conducted over the inner
continental shelf to depths of 55 m, and the fish meal and oil reduction
fishery for menhaden, conducted within 24 km of shore near the Mississippi
River delta. Many of the commercial fish species in this region, as well as
the white and brown shrimp, are estuarine dependent (i.e., they utilize
estuaries as spawning and/or nursery areas during part of their life cycle).
134
-------
7. ENVIRONMENTAL CONSIDERATIONS RELATED TO MANGANESE
NODULE PROCESSING WASTE DISPOSAL
Since no empirical data are available on the effects of marine disposal
of manganese nodule processing wastes, an environmental assessment must
utilize information on the physical/chemical characteristics of the wastes
(Chapter 5), the available ocean disposal technologies (Chapter 3), and the
individual characteristics of representative disposal areas (Chapter 6) to
arrive at an evaluation of significant environmental considerations. This
evaluation will include a discussion of how each factor affects the
magnitude, duration, or spatial extent of potential effects. In addition,
available information on the effects of marine disposal of other wastes will
be examined to determine its relevance to predicting effects of manganese
nodule processing waste disposal.
The discussion which follows will be divided into three sections.
First, environmental effects of the marine disposal of other wastes will be
described in some detail. Wastes considered include mine tailings, drilling
muds, dredged material, and sewage solids. Next, generic effects of the
marine disposal of manganese nodule processing wastes will be discussed for
each of three possible receiving environments: open ocean, outer
continental shelf, and nearshore. Factors considered will include the
characteristics of the wastes, the various methods of disposal, and the
characteristics of each environment which will influence the type of effect
on the biota. An attempt will then be made to estimate the relative
significance of the identified potential environmental effects. Finally,
this information will be combined with the characteristics of each
representative disposal area to arrive at significant environmental
considerations for each area. These are expected to be the primary
environmental considerations to be taken into account in determining the
acceptability of manganese nodule processing waste for ocean disposal and
for selecting a possible site for the disposal of these wastes.
MARINE DISPOSAL OF OTHER WASTES
An initial review of the marine disposal of other wastes has been
conducted to provide examples of the kinds, duration, and extent of impacts
attributable to characteristics of the wastes or of the receiving water
environment. Emphasis has been placed on metalliferous wastes or wastes
containing a substantial degree of metallic contaminants. Mine tailings are
perhaps most similar to manganese nodule processing wastes, due to their
largely inorganic nature and their content of various metals. Hence, the
discussion which follows will emphasize environmental investigations of the
effects of these wastes. While not as comparable to manganese nodule
processing wastes, the disposal of other wastes (e.g., drilling muds,
dredged material, sewage solids) will also be discussed with regard to their
environmental effects.
135
-------
Mine Tailings
The physical/chemical characteristics of mine tailings are highly
variable, even among mines extracting the same minerals (see Appendix C).
Sources of this variation include differences in the grain size and
crystalline structure of the tailings, and differences in the chemical
composition of the tailings and associated effluent. This variation among
mine wastes complicates assessment of the environmental consequences of
tailings and effluent disposal. Accurate assessment of the environmental
consequences of mine waste disposal is further complicated by between-site
differences in the physical, chemical, and biological characteristics of the
receiving environments.
Despite the high degree of variation among mine wastes and receiving
environments, general statements about the environmental impacts of mine
waste disposal are possible. For the marine environment, Ellis and
Littlepage (1972) provide a review of such impacts. They divide the general
effects of mine waste disposal in the marine environment into primary and
secondary effects. Primary effects include:
1. Acute poisoning. Acute poisoning may result from the
"inadequate removal of poisons from discharged effluent."
2. Chronic poisoning. Chronic poisoning may result from the
introduction of sub-lethal levels of toxic substances into
the receiving environment. Organism response may include
reduced growth, reduced fecundity, reduced longevity, and
other evidences of ill health.
3. Enrichment. Enrichment and eutrophication may occur through
the addition of nutrients into the ecosystem.
4. Suffocation. Suffocation of the biota may result from
direct smothering by particulates or from anoxia due to the
decomposition of organic matter in the water column.
5. Temperature and salinity effects. Alterations of
temperature and/or salinity in the receiving environment may
alter metabolic rates, osmotic regulation, and behavioral
patterns of the biota. Responses of the biota may be
diverse and may occur at the individual, species, or
ecosystem level.
Secondary effects include:
1. Bioaccumulation of toxic substances. Plants and animals in
the receiving environment may accumulate toxic substances in
their tissues.
2. Changed standing stocks and production rates. The
introduction of "abnormal chemicals", including toxic
136
-------
substances and nutrients, may alter biological production
and cause changes in the structure and function of the
ecosystem.
3. Species losses and population explosions. Alterations of
the receiving environment by pollutants may cause the
elimination of some species and the enhancement of others.
Ecosystem structure may be greatly altered.
Of the many possible primary and secondary effects discussed by Ellis and
Littlepage (1972), bioaccumulation of toxic substances has been the subject
of increasing research efforts in recent years. Much of the impetus for
this research comes from the realization that bioaccumulation is a route by
which toxic substances may be introduced into the human population by
ingestion of seafood organisms. Mine wastes pose a potential for
bioaccumulation since residual metals are present in the tailings and
effluent, and these metals may be assimilated or concentrated by the biota
in the receiving environment. The toxicity of many metals is well known
(cf. Eisler 1979).
Metals may be assimilated by marine organisms from water or food. To
be incorporated into an organisms tissues, metals must be available to the
biota in a dissolved form. The rate at which metals dissolved in mine
effluent are discharged into the receiving environment, and the rate at
which metals are released from mine tailings into seawater, or within the
organisms' digestive tracts, are, therefore, critical. Laboratory
experiments 'by McGreer et al. (1980) demonstrated that the uptake of metals
from mine tailings is "generally proportional to the concentration of metals
in seawater" for the deposit feeding bivalve Macoma balthica.
Whereas metals dissolved in the liquid effluent from a mining operation
will be discharged into the marine environment only when the mill is
operating, metals from disposed tailings may continue to be released into
the marine environment in dissolved form, or be ingested by biota, long
after the mining operation ceases. Submerged tailings may therefore have
long-term effects on the indigenous biota.
Recent studies indicate that characteristics of both the tailings and
the receiving environment will influence levels at which metals contaminate
the resident biota. From their comparison of the bio-uptake of metals from
three mines, McGreer et al. (1980) concluded that "the metal-binding
associations within the mine tailings were responsible for controlling metal
release." Thus, the geochemistry of the tailings directly influences the
concentrations of dissolved metals, which in turn influence the levels of
contamination in at least some indigenous organisms. Sediment diagenesis of
metals in the disposed mine tailings may also contribute to high
concentrations of dissolved metals in the pore waters of estuarine
sediments. Subsequent diffusion of these dissolved metals to the
sediment-water interface may result in high concentrations of metals in the
overlying waters, and may prevent metals in the underlying sediments from
being retained in the deeper parts of the sediment deposit (Elderfield and
Hepworth 1975). Bioturbation of sediments may also act to increase the
137
-------
availability of sediment metals to overlying waters. The upper reaches of
estuaries may be particularly sensitive to the disposal of mine tailings
since circulation and sedimentation patterns may tend to retain metals in
their upper reaches (Merefield 1976; Yim 1976).
Copper Mines —
Impacts of tailings on Rupert Inlet and adjacent waters have been
studied extensively since the Island Copper Mine began operation in 1971.
Most of the mine tailings are deposited on the bottom of Rupert Inlet soon
after discharge, but some small particles (< 5 urn) become suspended in the
water column (Goyette and Nelson 1977). Additional quantities of small
particulates are subject to resuspension by tidal currents (Goyette and
Nelson 1977). Increased concentrations of copper and zinc in the sediments
are associated with the tailings.
The tailings have gradually moved along the bottoms of Rupert and
Holberg Inlets. Movement of the tailings away from the deposition point is
thought to be caused primarily by tidal currents (Goyette and Nelson 1977),
although slumping of tailings from one wall of the fjord to the opposite
wall may also occur (Evans and Poling 1975). Goyette and Nelson (1977) note
that the deposition of tailings was initially predicted by Utah Mines
Ltd. to occur only in Rupert and Holberg Inlets at depths greater than
100 m. This prediction was based on limited current data collected at two
stations, the first between Quatsino Narrows and Hankan Point and the second
near the mine site. Utah Mines Ltd. interpreted these data to indicate that
current velocity would be highest above a depth of 60 m, and that a zone of
vertical stability would exist from 60-m depth to the bottom of the inlet
(Goyette and Nelson 1977). Contrary to prediction, tailings deposition in
the nearshore area was increasing during the summer of 1975, and geochemical
data suggested that tailings were also spreading into Quatsino Sound
(Goyette and Nelson 1977).
Turbidity has increased markedly in Rupert and Holberg Inlets,
primarily through the resuspension of the fine particulates by currents
(Goyette and Nelson 1977). Whereas most of the suspended particles were
predicted to occur at depths in excess of 60 m, high turbidity levels are
usually encountered below 30 m (Goyette and Nelson 1977). Furthermore,
"extreme turbidity can exist throughout the entire water column" (Goyette
and Nelson 1977). Disposal of tailings into Rupert Inlet has not
appreciably altered levels of "dissolved" (e.g., passing through a 0.45 urn
filter) heavy metals, total cyanide, total mercury, pH, salinity,
alkalinity, or dissolved oxygen in the water column (Evans et al., 1972).
The major biological impact of tailings disposal into Rupert Inlet has
been the obliteration of the benthic community. After three and one-half
years and the disposal of 35 million tons3 of tailings, mine-derived
a The comparable volume of nodule processing rejects from a single plant
over a 3 1/2-year period would be approximately 10.5 million tons.
138
-------
tailings in excess of 30 cm thickness had spread throughout the trough of
Rupert Inlet and about 3 km into the trough of Holberg Inlet (Evans and
Poling 1975). The area covered by such tailings was about 1.6 km^ at the
time of the report by Evans and Poling (1975). The area so affected may now
be substantially larger, since tailings were continuing to spread throughout
Rupert and Holberg Inlets in 1973-74 (see Goyette and Nelson 1977).
Smothering does not occur in shallow water or in the more distant portions
of Holberg Inlet, but the deposition of sub-lethal accumulations of tailings
appears to reduce biological productivity (Jones and Ellis 1976; Goyette and
Nelson 1977; Ellis 1978). The diversity of the benthic community is reduced
on tailings deposits up to 26 cm thick, but on tailings deposits of 9 cm
thickness or less, species assemblages are indistinguishable using
multivariate analysis techniques (Ellis 1978).
In contrast to the benthos, other biological communities in Rupert
Inlet appear to be little influenced by the disposal of tailings. After
three and one-half years of tailings disposal, Evans and Poling (1975)
concluded that there had been "no discernible influence" on phytoplankton,
zooplankton, intertidal macroinvertebrates, intertidal fishes, intertidal
and sublittoral algae, Dungeness crabs, and pelagic and demersal fishes.
The authors failed to find statistically significant correlations between
variations in these biological communities and the distribution of tailings.
The bioaccumulation of metals is evident only in the tissues of some
species of shellfish. Other organisms are apparently unaffected (Evans et
al., 1972; Ellis 1978). Ellis (1978) credits effluent controls and the use
of the deep outfall for "controlling traditional metal accumulation
problems" which have characterized tailings disposal into shallow water
environments. Elevated levels of copper have been found in two species of
bivalves, however. Whereas control levels of copper are 5 to 87 ug/g in the
mussel Mytilus edulis, levels at Hankin Point (at the junction of Rupert and
Holberg Inlets) are 82 to 150 ug/g (Goyette and Nelson 1977). Temporal data
on the accumulation of copper in the tissues of M. edulis suggest that
levels do not increase consistently through time ("Ellis 1978). Levels of
copper in the tissues of the deposit-feeding bivalve Macoma iris appear to
be inversely correlated with distance from the tailings disposal area.
Tissue levels at Red Island, east of the disposal site, averaged 30 ug/g,
tissue levels at a location just west of the disposal site averaged 66 ug/g,
and tissue levels in Holberg Inlet averaged 30 ug/g (Goyette and Nelson
1977). In summary, Ellis (1978) concluded that while no short-term problems
were evident for metals accumulation in the biota of Rupert and Holberg
Inlets, insufficent time had elapsed for the evaluation of long-term
problems.
Impacts of the disposal of copper tailings from the Britannia mine on
the ecology of Howe Sound, British Columbia (Figure 40) have been studied
less extensively than impacts in Rupert and Holberg Inlets; nevertheless, a
considerable body of information exists. As in Rupert and Holberg Inlets,
the most obvious impact of the tailings is the complete burial of the
natural sediments in a portion of Howe Sound, and the "substantial
disruption" of solid substrate habitats by tailings (Goyette 1975). The
benthic biota is completely absent in the area adjacent to the Britannia
139
-------
town docks to a depth of 33 m (McDaniel 1973). Tailings completely cover
this part of Howe Sound, blanketing the natural substrate and precluding the
development of a benthic community. Areas immediately north and south of
the tailings disposal site also exhibited depauperate benthic communities
(McDaniel 1973).
In nearshore areas, effluent and tailings from the Britannia mine
"visibly discolored the shoreline" for 1 km on either side of the mine, and
caused biological diversity to be reduced for up to 2 km distant (Levings
and McDaniel 1973; Ellis 1978).
Biological observations by submersible indicate that the benthic fauna
in the area consists of a "sparse fauna of very large animals" (Levings and
McDaniel 1973). Levings and McDaniel (1973) reported that benthic organisms
are particularly sparse in those deeper parts of Howe Sound where a
turbidity cloud resulting from effluent and tailings disposal exists within
20 m of the bottom. They speculated that the obi iterative effects of the
tailings would probably be long-term, since larvae would not find the areas
of constant tailings deposition and reworking to be suitable for settlement.
Levings and McDaniel (1973) observed "normal" benthic communities in areas
north and south of the tailings deposits.
Concentrations of copper and zinc in the sediments of Howe Sound are
greatly enhanced when compared with four "control" areas within Howe Sound
(Thompson and McComas 1974). In a subsequent study, Thompson and Paton
(1978) found the interstitial waters of the surface sediments to be enriched
in dissolved copper when compared with the underlying, deeper sediments.
Thompson and Paton (1978) speculated that "diagenetic and/or complexation
processes" were responsible for the release of dissolved copper from the
sediments in the near-bottom waters, which exhibited higher concentrations
of dissolved copper than did surface and mid-depth waters.
Concentrations of copper and zinc in the tissues of the mussel Mytilus
edulis and the oyster Crassostrea gigas in Howe Sound and adjacent waters
indicate widespread contamination of these filter-feeding shellfish in Howe
Sound, where tissues of specimens were green. The sources of the copper and
zinc are speculated to be the acid mine wastes disposed of in Britannia
Creek (Goyette 1975) and the submerged tailings in Howe Sound (Thompson and
McComas 1974). Thompson and Paton (1978) caution, however, that the
bioavailability of copper from the several possible sources in Howe Sound is
unknown, since the chemical speciation associated with each source is
unknown.
Limited environmental data from the Jordan River Copper Mine (B.C.)
document some of the same types of impacts which were observed at the Island
Copper Mine and the Britannia Copper Mine, but on a smaller scale because of
the smaller discharge volume (Table 40). Tailings disposed of at 3 m depth
smothered the benthic fauna over a few tens of square meters in the
immediate discharge area (Ellis 1978). Suspended solids concentrations were
occasionally elevated near the outfall, but levels of dissolved and
particulate heavy metals in the water column did not increase (Ellis 1978).
Beach sediments near the outfall exhibited significantly higher (probability
140
-------
level not given) concentrations of copper than did control sites, but the
data did not indicate that copper levels in the sediments near the outfall
were increasing during the last 2.5-year period of operation (Ellis 1975).
Six months after disposal ceased, copper levels in the sediments near the
outfall and downstream of the outfall (by longshore drift) remained high,
while levels upstream of the outfall dropped. Ellis (1975, 1978) found
copper levels in the tissues of littleneck clams (Protothaca staminea) to be
elevated near the discharge, but concluded that these higher levels were
caused by uncontrolled beach discharges prior to the last operational period
(1972-1974), and that the regulated discharge of 1972-1974 did not
contribute to the contamination of littleneck clams.
Although the Atlas Consolidated Copper Mine (Cebu, Philippines)
disposes of over 68,000 tons of tailings per day-, little information on the
environmental impacts of those tailings is available. At the time of
disposal, tailings flow down a trench into Tanon Strait. By 1972, the
tailings stabilized at a minimum depth of 12 m below sea level on the floor
of Tanon Strait, and reached an equilibrium slope of 20 percent (Salazar and
Gonzales 1973). Deposition of tailings did not occur beyond 244 m from the
discharge at that time. Salazar and Gonzales (1973) report "no adverse
effects on the marine life in the area," and state that the discharge point
has become a favorite fishing area. The basis for these conclusions are not
given.
Data collected by Castilla and Nealler (1978) indicate that the
nearshore disposal of-copper tailings from the El Salvador Copper Mine has
caused substantial ecological damage. Tailings have accumulated in Chanaral
Bay (Figure 42), the first disposal area, to a depth of 2 m. Turbidity is
high, as indicated by Secchi disk readings of 2 to 3 m in Chanaral Bay and
only 0.6 m in the present disposal area at Caleta Palito.
Castilla and Nealler (1978) found Chanaral Beach to be totally devoid
of sandy beach macrofauna. Adjacent hard substrates were also devoid of
biota. Although no data on plankton were presented, the authors stated that
they believed plankton communities in Chanaral Bay to be adversely affected
by the resuspension of tailings caused by waves and currents.
Prior to the discharge of tailings at Caleta Palito, "rich" intertidal
and subtidal benthic communities were present (Castilla and Nealler 1978).
Initiation of the discharge saw "massive fish and molluscs mortalities"
within a few days, and the "substantial" alteration of the remaining biota
by chemical and physical processes. The mass mortalities of sea stars,
limpets, crabs, urchins, fishes, and littoral algae which occurred in July,
1975, the first year of the discharge, recurred again in July, 1976
(Castilla and Nealler 1978). The discharge at Caleta Palito also causes
greenish pyrite slicks on the water surface, and shoaling of the nearshore
receiving environment.
The copper mine at Repparfjord, Norway, has been in operation since
1972, but no data on the environmental impacts of the tailings are presently
available. Doughty (1975) states only that the tailings have not
contaminated the fjord, and that the fishing season has never been
disrupted.
141
-------
Iron Mines--
Tailings from the Ma On Shan Iron Mine in Hong Kong have spilled over
the nearshore retaining dams (Figure 45) and into the littoral and
sublittoral environment (Wong et al., 1978). Consequently, substrate
characteristics in that area have been altered. Compared with sediment at
Long Harbour and Railway Beach, sediments near the Ma On Shan mine are of
finer texture (Table 46) and more alkaline (Table 47), and contain lower
amounts of organic carbon, total nitrogen, and available phosphate (Table
47). Wong et al. (1978) reported that sediments in the tailings disposal
area exhibited higher levels of copper, iron, manganese, lead, and zinc than
sediments at Long Harbour and Railway Beach. Only levels of cadmium and
chromium were not enhanced at the disposal site.
Biological effects of tailings disposed at Ma On Shan were ascertained
through comparisons of macrofauna at the disposal site with macrofauna at
Long Harbour and Railway Beach. Effects of tailings disposal included: 1)
the development of a fauna dominated by burrowing forms, especially molluscs
and crustaceans, 2) a reduction in the number of species present, 3)
enhanced abundances of the dominant mollusc and crustacean species, and 4)
expanded depth ranges of two dominant brachyuran crabs (Wong et al., 1978).
Bioassays of tissues from crabs and tissues and shell from edible bivalves
revealed enhanced body burdens of copper, iron, manganese, lead, and zinc,
compared with body burdens of those metals in specimens from Long Harbour
and Railway Beach (Wong et al., 1978). Body burdens of cadmium and chromium
were not'elevated at the tailings disposal site.
Seven years after the abandonment of the Kennedy Lake Iron Mine on
Toquart Bay, British Columbia (Figure 46), Levings (1975) conducted a series
of biological observations along transects perpendicular to the shoreline.
He found the distribution of tailings on the beach and in the bay to be
"patchy". Patches of black magnetite sand lost during the loading process
exhibited the greatest variety of benthic infauna, including littleneck
clams (Venerupis japonica). Tailings deposits were found to support only
populations of the soft-shelled clam Mya arenaria. "Natural" substrates in
adjacent areas ranged from coarse sands to cobbles. Few organisms were
observed in the coarse sand, but the hard substrates were colonized by
numerous epifauna! forms.
Lead-Zinc Mines--
No data on present environmental conditions in the receiving
environment near the Greenex Lead-Zinc Mine (Figure 47) are available at the
time of this writing. However, after 1 year of operation (1974), toxic and
burial effects of tailings from the mine had obliterated 90 percent of the
benthos in Agfardlikavsa Fjord (Anon. 1975). Concentrations of zinc,
cadmium, and lead were high in the waters of Agfardlikavsa Fjord and in the
proximal portion of Qaumarujuk Fjord. Metals concentrations in the biota
were also elevated: concentrations of lead and zinc in the tissues of
mussels and seaweeds were as much as an order of magnitude higher than
background levels at distances up to 5 km from the discharge point
(Anon. 1975).
142
-------
Bauxite Mines--
Red mud is not discharged into the marine environment at the bauxite
refinery in Gove, Australia (Figure 49). However, incomplete neutralization
of supernatant waters prior to their discharge into the estuary temporarily
caused problems (Baseden 1976). Final neutralization of supernatant liquid
by seawater in the estuary caused the deposition of white deposits of
hydrated alumina and magnesium hydroxide in the estuary and on the
mangroves. Some dead fish were observed, probably the victims of gill
agglutination. The neutralization problem has since been eliminated, and
after 18 months of operation, the mean numbers of benthic taxa at sites near
the discharge point did not differ significantly (probability level not
given) from pre-operational levels. It should be noted, however, that
mangroves in areas adjacent to the disposal channels are being stressed by
the discharge (Baseden 1976).
Although red muds are not discharged into the marine environment at
Gove, they have been discharged elsewhere. Red muds owe their color to the
presence of iron oxide (FenOg) which may constitute 2 to 25 percent of the
mud. Blackman and Wilson (1973) review the effects of red muds on marine
fauna, and stress that the toxicity of red mud varies due to differences in
the chemical compositions of bauxite ores and differences in treatment
processes. In general, red muds in suspension are more toxic than red muds
deposited on the bottom. The toxicity of red muds also varies with the
organism. Toxicity tests with the fish Agonus sp. suggest that red muds in
suspension are especially toxic to fish.After comparing the environmental
impacts of red mud disposal in two different marine receiving environments,
Blackman and Wilson (1973) concluded that hydrographic characteristics of
the receiving environment are the key factors which determine the extent and
severity of impacts associated with red mud disposal. Impacts may be
minimal or absent where circulation is good and turbulence within the water
column is high. Alternatively, severe impacts may occur in receiving
environments with poor circulation.
Potash Mines--
Although the Cleveland Potash Mine in Boulby, Yorkshire is operational,
no environmental data are presently available. Design predictions indicate
that the effluent will be jetted through nozzles on the sea bed. Dissolved
solids are expected to be reduced to 36 ppt within 30 m of the discharge,
and currents are expected to disperse much of the insoluble material
(Cleasby et al., 1975).
Drilling Muds
Drilling muds are complex mixtures of barite, clay minerals, and
several additives which are discharged to the sea near drilling operations.
Drilling muds may contain relatively high levels of potentially toxic trace
elements such as barium, chromium, zinc, copper, and lead. The metals in
drilling mud discharges may occur as components of the mineral additives, as
organic complexes (e.g., chrome lignosulfonate), or as part of the formation
143
-------
drill solids. Numerous laboratory and field studies have been conducted on
the effects of drilling mud discharges to the marine environment.
Near a drilling site in the area of the shelf break (120 m depth) along
the mid-Atlantic coast, Menzie et al . (1980) observed lower abundances of
macrobenthic organisms, although the trophic relationships among the
dominant infauna, as represented by polychaete feeding guilds, were
apparently not affected by the discharge (Maurer et al., 1981). The density
decreases were attributed to an increase in the clay content of the
sediments and increased predation by demersal fishes and megainvertebrates,
which were attracted to the area by increased microrelief of the substrate.
Sessile benthic organisms were also smothered by the discharge. Several
organism groups had elevated tissue concentrations of barium and mercury
following drilling discharges; however, no simple correlation existed
between the metal concentrations in the sediments and in organism tissues
(Mariani et al . , 1980). Chromium concentrations were elevated in
post-discharge polychaete samples, but were unchanged in sediments,
molluscs, and brittle stars. This relationship emphasizes the need to study
metal availability according to species groups and discharge
characteristics, since the drilling mud discharged at that site contained
over 1,100 mg/kg (dry weight) of chromium (Ayers et al., 1980).
Smothering of benthos and elevated sediment metal concentrations were
also observed at a drilling mud discharge site in the Beaufort Sea (Crippen
et al., 1980). There was no correlation between sediment metal
concentrations and organism tissue levels, however, and the only evidence
for bioaccumul ation was for mercury, which was elevated 185 times above
background levels in surficial sediments.
Hydrodynamic characteristics near drilling mud discharge sites have
been shown to have a pronounced effect on solids depositional patterns and
benthic effects. At a well site in lower Cook Inlet, Alaska, (^60 m depth)
strong currents prevented any detectable localized accumulation of drilling
solids (Houghton et al., 1980). There were also no measurable effects on
benthic macroinvertebrate communities near the discharge site (Lees and
Houghton 1980). Meek and Ray (1980) detected measurable settling of
drilling solids within 150 m of a site on Tanner Bank, California (~60 m
depth). Following discharge, however, wave and current induced resuspension
of deposited particles resulted in 70-90 percent of the discharged material
being transported away from the site and dispersed to undetectable levels.
Dredged Material Disposal
Dredged material removed during harbor and channel maintenance
operations is disposed into the nearshore marine environment in many coastal
areas of the U.S. Although the biological effects of dredged material
disposal are relatively well documented by laboratory bioassays and field
surveys, the potential impacts are not directly comparable to the case of
manganese nodule reject disposal. The potential acute effects of burial of
benthic organisms are probably similar for the two wastes, although the
potential recovery of normal benthic communities may be quite different.
144
-------
The immediate effects of dredged material disposal on the benthos are
associated with smothering of organisms unable to burrow to the surface of
the newly-deposited sediments. Examples of such organisms include
tubiculous polychaetes and some amphipods. Even for some relatively active
forms, the change in natural sediment grain size or compaction may result in
the new substrate being unacceptable. Thus, the immediate effects of
sediment deposition are usually declines in species richness and biomass of
infaunal and epifaunal organisms (see, for example, Boone et al., 1978;
Oliver et al., 1977).
The first recovery stage following deposition of dredged material is
usually evidenced by an immigration of large megafaunal organisms, such as
peracarid crustaceans, demersal fishes, and echinoderms. This early
recolonization phase is obviously affected by the availability of potential
recruits from surrounding habitats. The second successional phase is
usually characterized by high abundances of opportunistic polychaetes. Such
species are usually subsurface deposit feeders, which utilize organic matter
contained in the deposited material.
Many infaunal and epifaunal organisms from coastal areas are adapted to
relatively high sedimentation rates or other sediment disturbances (e.g.,
longshore transport or wave-induced resuspension). These organisms display
considerable ability to tolerate single-event covering by natural sediments.
Swartz et al. (1979) reported that test organisms (bivalve molluscs,
polychaetes, amphipods, and cumaceans) did not have increased mortalities at
10 days following burial by up to 30 mm of clean sandy sediment (209 urn mean
grain size). With the exception of cumacean mortalities in very coarse
sediments, the test assemblage was not adversely affected by alterations in
sediment grain size (26 to 1,395 urn mean grain size) after a 15 mm burial.
In a series of laboratory exposures simulating dredged material disposal,
Maurer et al. (1978) found that many of the test species (e.g., polychaetes,
amphipods, and gastropod molluscs) were able to successfully migrate through
10-20 cm deep layers of deposited sediment. The authors emphasized,
however, that survival following burial was highly dependent upon sediment
type, species, and temperature. Thus, extrapolations of the data to field
situations should be done with caution.
Although motile benthic fauna may tolerate considerable sedimentation,
sessile epifauna (e.g., corals, oysters, mussels) are sensitive to
smothering by a relatively thin layer of sediments. For these organism
groups, the impacts of sediment smothering may be long-lasting, since
repopulation would require recruitment by larval settling and the modified
substrate may be unacceptable for larval attachment.
Dredged material may contain from < 1 to 18 percent organic matter and
therefore has nutritional characteristics considerably different from the
primarily inorganic nodule rejects and wastes. The inorganic nature of the
rejects will probably restrict the initial recolonization by opportunistic
species. Colonization by megafauna may also be altered because of lack of
infaunal prey items.
145
-------
Sewage Solids
Sewage solids are discharged to the marine environment through outfalls
and by dumping. These wastes have a relatively high organic component and,
as such, are considerably different from the entirely inorganic nodule
rejects. Sewage solids have been shown to cause severe modifications in the
structure of benthic communities in localized areas near sewage outfalls
(Bascom et al., 1978; Mearns 1981). However, many of the effects may result
from sediment oxygen depletion in areas of high solids deposition and from
modifications in normal trophic relationships due to increased organic
content of the sediments. The sewage wastes from large municipal areas
generally have high levels of metals such as silver, cadmium, zinc, copper,
nickel, chromium, and lead. Thus, although the metals are primarily
adsorbed onto organic particulates in sewage wastes, examination of the
degree and extent of contamination provides some indication of the potential
effects of manganese nodule reject disposal if differences in
bioavailability are disregarded.
Extensive studies near highly-contaminated areas of the southern
California Bight (Los Angeles County sewage outfall) have demonstrated
significantly higher tissue burdens of several metals in filter-feeding
bivalve molluscs such as mussels (Mytilus californianus) and rock scallops
(Hinnites giganteus) (Young et al., 1978j~^ A lesser degree of elevated
tissue metal concentrations has also been detected in other invertebrates
such as abalone, rock crab, and spiny lobster. An important finding of the
southern California studies is that demersal fishes (Dover sole; Microstomus
pacificus) living in direct contact with the highly-contaminated sediments
near a major outfall displayed no evidence of overall tissue contamination
by seven metals (McDermott et al., 1976).
A similar pattern has been observed at ocean disposal sites receiving
sewage sludge and dredged materials in the New York Bight and Long Island
Sound. Grieg et al. (1977) reported that windowpane flounder (Scophthalmus
aquosus) collected near the dump sites did not accumulate metals to a
greater degree than at a control site. The only metal showing increased
concentrations in rock crabs from the disposal sites was silver
(approximately 3x elevation). Grieg and Wenzloff (1977) also found no
evidence of bioaccumulation of metals in winter flounder (Pseudopleuronectes
amen can us) collected from the New York Bight sewage sludge dumpsite. TfTe
ability of fishes in contaminated areas to regulate toxic metals is also
indicated by studies from the Derwent Estuary, Tasmania (Eustace 1974), the
Firth of Clyde, U.K. (Halcrow et al., 1973), and deepwater disposal site
No. 106 (Grieg et al., 1976).
Summary
A review of the impacts of other wastes in the marine environment
indicates the general kinds of potential impacts that may occur following
manganese nodule processing waste disposal. Although no currently produced
wastes could be expected to accurately simulate manganese nodule rejects,
mine tailings and, to a lesser extent, drilling muds probably provide the
most applicable information on generic impact types. This is because these
146
-------
wastes are both inorganic and fine grained. Other substances disposed of in
the marine environment have significant organic components (e.g., sewage
solids and dredge spoils), resulting in quite different potential impacts on
marine organisms.
The available ecological data on the marine disposal of mine tailings,
most of which deals with impacts of the disposal of copper mine tailings,
indicate that the primary effects are the smothering of benthic communities
and the bioaccumulation of certain metals in some animal species. The
effects of the burial of natural benthic substrates by a layer of inorganic
particulate mine tailings vary with the depth of burial. Whereas deep
burial may result in a total obliteration of the pre-existing benthic
communities, sublethal accumulations may only result in a reduction in
biological productivity. In the vicinity of the Island Copper Mine, for
instance, benthic diversity was reduced on tailings deposits up to 26 cm
thick, but on deposits of less than 9 cm, species assemblages were
unchanged.
Although mass mortalities of fishes, molluscs, limpets, crabs, urchins,
sea stars, and littoral algae were reported upon initiation of the tailings
discharge from the El Salvador Copper Mine, extensive studies near the
Island Copper Mine have failed to detect any influence on phytoplankton,
zooplankton, intertidal macroinvertebrates, intertidal fishes, intertidal
and sublittoral algae, Dungeness crabs, and pelagic and demersal fishes.
Hence, it is not clear that mine tailings discharges consistently impact
communities other than the subtidal benthos.
With regard to bioaccumulation of metals, the only organisms which
demonstrate a consistent pattern of metal uptake in the presence of mine
tailings are the bivalve molluscs (e.g., mussels, clams, oysters). Even so,
bioaccumulation is apparently dependent upon organism species and the
physical/chemical form of the metal. The potential for bioaccumulation of
metals contained in the waste depends on the concentration of the dissolved
metal in the effluent, the release of dissolved metals from the disposed
tailings into seawater, and the release of dissolved metals from ingested
particulates in the digestive tracts of the organisms in question. It seems
apparent that metal release from the disposed tailings is a function of the
metal-binding capacity of the tailings, which in turn is a function of the
geochemistry of the tailings. In this sense, these results are not directly
applicable to an estimation of the potential for bioaccumulation of metals
from manganese nodule processing wastes, since the metal-binding capacity of
these wastes is unknown at this time.
The deposition of drilling muds on the ocean floor has been shown to
result in a reduction in the abundance of macrobenthic organisms, although
the trophic relationships among the dominant infauna were not affected. The
reductions in abundance appeared to be related both to a change in the grain
size of the sediments and to increased predation by fishes and
megainvertebrates. Sessile benthic organisms were also smothered by the
drilling mud deposits. Although drilling muds may contain relatively high
levels of metal ions such as chromium, zinc, copper, and lead, and although
the deposition of drilling muds on the seafloor may result in higher
147
-------
sediment concentrations of such metals, evidence for the uptake of these
metals by organisms found in the presence of such deposits is inconsistent.
In most respects, sewage solids and dredge spoils are sufficiently
different from manganese nodule processing wastes that an examination of
their ecological impact on marine communities is of little value for
predicting the effects of the marine disposal of manganese nodule processing
rejects. While sewage solids often have high levels of metals such as
silver, cadmium, zinc, copper, nickel, chromium, and lead, and
bioaccumulation of several of these metals has been demonstrated for marine
organisms inhabiting the area around large sewage outfalls, the
metal-binding capacity of the largely organic sewage solids is likely quite
different from the metal-binding capacity of manganese nodule processing
rejects, and therefore extrapolation of these results is unwarranted.
GENERIC EFFECTS OF MANGANESE NODULE PROCESSING REJECTS DISPOSAL ON MARINE
COMMUNITIES
Possible Biological Impacts of the Deep Ocean Disposal of Manganese Nodule
Processing Rejects
Wastes resulting from the smelting of manganese nodules would likely
consist of two fractions: a fine particulate fraction having a particle
size similar to that of clay and a coarse fraction having a particle size
similar to that of coarse sand. Disposal of the fine particulate matter
would be subject to many of the same considerations to be discussed later
with regard to the disposal of the fine particulate wastes from the various
hydrometallurgical processes. In particular, the settling velocities of the
particles in these wastes would likely be of similar magnitude, and hence,
those factors affecting where, when, and how these materials were deposited,
and how long they might be expected to remain in the water column, would be
similar. They may, of course, have different chemical characteristics.
Nevertheless, for the purposes of this discussion, the effects of the
disposal of this fraction on open ocean communities will be considered to be
similar to those discussed below for the hydrometallurgical process wastes.
Due to the large particle size of the coarse fraction (> 1.7 mm),
settling velocities would be much more rapid than those of the fine
particulates. In fact, even in water of several thousand meters depth, the
coarse fraction would likely settle to the bottom on a time scale of hours.
Hence, this waste fraction will not likely have any appreciable impact on
biotic communities within the water column. Depending upon the dispersal of
this slag, it may cover and kill the benthic communities in a given locale,
although the area involved would likely be small. Since natural
sedimentation rates in the deep ocean are quite slow (on the order of
millimeters per thousand years), slag deposited on the ocean floor may not
be covered for a very long time, and hence, the soft-substrate benthic
communities at that locale, which are adapted to living on a substrate of
clay-size particles, would not be expected to recover until burial was
complete. If, as expected, the slag is relatively inert, leaching of heavy
metals or other potentially toxic constituents would not be expected to
occur, and hence, biological uptake of these materials is unlikely.
148
-------
Wastes resulting from the various hydrometall urgical processes would
consist of a slurry of fine particulate matter and various dissolved
substances. The communities impacted by the deep ocean disposal of such
wastes and the nature of those impacts would be influenced by the method of
introducing the wastes into the ocean. The waste slurry could be dumped en
masse in a manner analogous to the barge dumping of dredge spoils, or the
slurry could be pumped overboard in various ways. The ship carrying the
wastes could be stationary or under way, and the wastes could be discharged
at the surface or by pipe to some subsurface depth. The rate of pumping
could also be varied.
The effects of inorganic particulate suspensions on marine fauna have
been reviewed in detail by Moore (1977). Responses of organisms to
particulate exposures are highly dependent upon species, life history stage,
particle characteristics, and water quality. Effects may be lethal,
sublethal, direct, or indirect. For example, sponges and corals are
generally highly susceptible to damage from sedimentation, while many adult
fishes can tolerate relatively high levels of suspended solids. In fishes,
juveniles are generally more susceptible to damage from particulates than
are adults. Adverse effects of suspended particulates on fishes are usually
associated with gill clogging, and highly angular particles have been shown
to cause more severe effects than spherical particles (Moore 1977). Major
potential impacts of suspended particulates on several organism groups are
summarized in Table 31.
If processing wastes are introduced into the euphotic zone, either by
dumping or by pumped discharge at the surface, phytoplankton could be
impacted in several ways. The fine particulate fraction of the slurry would
cause some increase in turbidity. The exact magnitude of this increase will
depend on the method of release of the wastes (e.g., a pumped discharge into
the surface layer would probably result in greater turbidity than would a
barge dump, which would leave a smaller residual amount of particulate
matter in the upper layers of the ocean). An increase in turbidity will
cause a decrease in the penetration of sunlight, and hence, decrease
phytoplankton photosynthesis.
There is also a possibility that the discharge of wastes could
stimulate phytoplankton production if appreciable quantities of limiting
nutrients were dissolved in the liquid fraction of the slurry. For
instance, phytoplankton production in much of the ocean is known to be
limited by the availability of fixed nitrogen, so appreciable quantities of
dissolved ammonium and/or nitrate could stimulate production. Other
possible stimulatory nutrients include silicate (necessary for the growth of
diatoms) and trace metals (like iron, which has been shown to be limiting in
some cases). Alterations in the availability of nutrients can also bring
about changes in the species composition of the phytoplankton community.
There is considerable variability in the response of phytoplankton
species to the addition of relatively small quantities of trace metals. The
most commonly reported response is a reduction in the rate of primary
production by the phytoplankton (cf. Knauer and Martin 1972; Patin et al.,
149
-------
TABLE 31. SUMMARY OF POTENTIAL IMPACTS OF INORGANIC PARTICIPATES
ON MARINE FAUNA
Organism Groups Potential Effect
Porifera Burial, clogging of pores, reduced pumping
Corals Burial, reduced larval settlement
Polychaeta Smothering, clogging of mucus nets, reduced larval
settlement
Copepoda Clogging of filtering mechanism, reduced food intake
Bivalve molluscs Reduced feeding efficiency, gill clogging, larval
mortality, reduced settling, shell deformities
Fishes Gill clogging and erosion, respiratory stress,
modified swimming behavior, smothering of eggs
Reference: Moore (1977).
150
-------
1974; Ibragim and Patin 1976). Toxic effects of metals such as copper and
zinc are apparently related to the free metal ion activity in the water,
rather than the total metal concentration (Sunda and Guillard 1976;
Canterford and Canterford 1980; Huntsman and Sunda 1981). The activities of
the free metal ions are difficult to predict, however, because they are only
partially determined by the total metal concentration in the water. For
most of the heavy metals (e.g., mercury, cadmium, silver, nickel, selenium,
lead, copper, chromium, arsenic, and zinc) the free metal ion activities are
a function of the pH and alkalinity of the water, the concentration of
natural organic or inorganic ligands (e.g., Cl~, S04=, or humic substances),
the concentration of competing metals, and the presence of adsorptive
surfaces (Sunda et a!., 1978). At any given time, it is likely that the
bulk of a given metal is bound up in organic or inorganic complexes, or
adsorbed onto the surface of suspended particulates. Iron/manganese oxides
are one of the most important sinks for metals in the marine environment,
and since manganese oxides are a major component of the manganese nodule
rejects, it is likely that most of the metals contained within the rejects
would be either adsorbed onto the particulate wastes, precipitated as
hydrous oxides, or bound in the original nodule matrix.
Even very low free metal ion activities may have adverse effects.
Toxic effects of copper on phytoplankton have been observed at cupric ion
activity levels (^10~9*6 moles/1) similar to those calculated for natural
ocean waters with no organic ligands present (Anderson and Morel 1978;
Reuter et al . , 1979). Thus, relatively small increases in natural cupric
ion concentrations in open ocean waters could potentially result in toxic
effects on sensitive species. While it is generally true that the free
ionic species of the metal is the most bioavailable, this is not always the
case. Certain organomercurial compounds are more toxic than mercury as
, for instance (Huntsman and Sunda 1981).
The free metal ion activities in the immediate vicinity of the disposal
of manganese nodule processing rejects in the open ocean will depend on
factors such as the total concentration of the metals, the pH of the
solution, the sorptive capacity of the particulate wastes, and the natural
organic or inorganic ligands present in the water. Generalizations
concerning the behavior of trace metals in the marine environment are
difficult to make since individual metals have different affinities for
naturally occurring ligands (Engel et al . , 1981). For example, copper has a
very high affinity for organic matter and could be expected to exist
primarily in association with organic ligands in nearshore areas of high
organic content. In contrast, cadmium has a low affinity for organic
ligands and could be expected to occur primarily as CdC^ in seawater.
For laboratory cultures, it is sometimes possible to estimate the metal
speciation, but for natural oceanic waters, the theoretical calculation of
the metal speciation is of little value because the nature, concentration,
and metal binding capacity of naturally-occurring organic ligands is unknown
(Canterford and Canterford 1980). Consequently, it would be difficult to
predict the effect on phytoplankton of the addition of a given quantity of
any of these metals to the euphotic zone of the open ocean.
151
-------
Whereas the initial effect of the addition of trace metals to
unpolluted waters may be a reduction in the rate of photosynthesis, the
primary effect will be to alter the species composition and succession of a
phytoplankton community (Huntsman and Sunda 1981). Phytoplankton species
are known to vary in their sensitivity to the toxicity of free metal ions
(Erickson et al., 1970). The result of their varying sensitivities may be
that the more resistant species replace the more sensitive species (Thomas
and Seibert 1977).
The residence time of these ions within the euphotic zone will depend
on the disposal method, the currents, the density stratification, and the
various processes affecting the residence time of the particulate fraction.
The multiplicity of factors affecting these processes makes it impossible to
predict the effects on phytoplankton. In all likelihood, such effects would
be relatively small in spatial extent, but their temporal persistence is
entirely unpredictable with information currently available.
Changes in either the level of primary production or the phytoplankton
species composition could cause changes at higher trophic levels, since, as
discussed earlier, nearly all life in the deep ocean is ultimately dependent
on phytoplankton for the fixation of carbon. Since impacts of waste
discharge on phytoplankton are likely to be extremely localized, however, it
is unlikely that higher trophic level effects would be significant. Fine
particulate matter will slowly sink out of the euphotic zone, and the
dissolved components of the discharge may be diluted beyond levels having
any impact on phytoplankton production. The presence of a strong
pycnocline, however,' could cause a retention of particulate matter deep
within the euphotic zone, and this could have important consequences for
phytoplankton, especially in those areas where phytoplankton are aggregated
at such depths (Chan and Anderson 1981).
Zooplankton throughout the water column are also potentially affected
by the deep-sea disposal of nodule processing wastes, but since the biomass
of zooplankton is much greater in the first several hundred meters, the
method of disposal will have a pronounced effect on the magnitude of any
such adverse impact. A pumped discharge of wastes into the surface layer
would likely have the greatest effect on zooplankton. Pumping the wastes to
intermediate depths (several hundred meters) could lessen potential impacts
on zooplankton. The effect of a barge dump would likely depend upon the
amount of the particulate matter remaining behind in the water column.
Adverse effects on zooplankton could occur in several ways. Some
dissolved components of the wastes may be directly toxic to zooplankton. It
has been demonstrated, for instance, that the free cupric ion may be toxic
to a freshwater crustacean, Daphnia magna (Andrew et al., 1977), while the
free cadmium ion may be toxic to a shrimp, Palaemonetes pugio (Sunda et al.,
1978). Since many zooplankton are filter feeders, the introduction of
inorganic particulate matter may interfere with zooplankton grazing. The
fine size of the particulate matter is similar to the size range of
phytoplankton ingested by zooplankton. This material could clog zooplankton
filtering apparatuses, abrade their mouth parts, and/or actually be ingested
by the animals. Such effects could cause zooplankton mortality or simply
152
-------
reduce the efficiency of their grazing on phytoplankton. Similar effects
have been demonstrated for marine planktonic copepods (Calanus
helgolandicus) which ingested large amounts of "red mud," the residual
substance after the extraction of aluminum from bauxite (Paffenhofer 1972).
If the particulate matter is inert, the zooplankton may simply pass it
through their guts and incorporate it into fecal pellets. This is, in fact,
a beneficial result of zooplankton grazing (i.e., the removal of fine
particulates from sea water and the incorporation of this material into much
larger pellets which consequently sink much faster out of the water column;
cf. Hirota 1981). If, however, heavy metals or other potentially toxic
constituents of the particulate matter leach out in the zooplankton guts,
they may be taken up by the zooplankton and incorporated into their tissue.
This may provide an avenue for this material to begin bioaccumulating.
Just as for phytoplankton, adverse effects on zooplankton may have
important ramifications for higher trophic levels, since nearly all are
dependent on the transfer of organic matter, produced by phytoplankton,
through the zooplankton, before it can become available to other animals.
Adverse impacts on zooplankton within the euphotic zone would likely be
extremely localized, however, for the same reasons as for phytoplankton.
Adverse impacts on zooplankton below the euphotic zone may be more
widespread and long lasting, depending upon the amount of particulate matter
retained within the water column. This in turn is dependent not only upon
the disposal method, but also upon the density profile of the water column
and ambient currents in the area. Zooplankton below the euphotic zone are
less likely to be adversely impacted by fine particulates, however, since
most species there are carnivores, rather than filter feeders.
Among the pelagic fishes of the open ocean, perhaps the most
susceptible stages to adverse effects of nodule processing wastes are the
eggs and larvae, together referred to as ichthyoplankton. Direct toxic
effects of dissolved substances on ichthyoplankton are a distinct
possibility. Engel and Sunda (1979) have demonstrated, for instance, that
the free cupric ion is capable of inhibiting hatching by the eggs of two
marine fish species, spot (Leiostomus xanthurus) and Atlantic silverside
(Menidia menidia). Other fishes may also be susceptible to the effects of
tree metal ions. Larval fish generally feed on phytoplankton and/or small
zooplankton. Their ability to do so may be impaired by the presence of
large quantities of fine particulate matter, which could decrease the
visibility of the food to these larvae. Ingestion of fine inorganic
particulate matter may also block food intake, as demonstrated for herring
larvae which ingested "red mud," the waste generated by aluminum production
from bauxite (Rosenthal 1971). Larval fish may also be indirectly affected
by adverse impacts on phytoplankton and/or zooplankton. Ichthyopl ankton
would be particularly susceptible to adverse effects if the processing
wastes were discharged at the surface, since most ichthyoplankton are found
near the surface. Discharging at depths below the epipelagic zone (0-100 m)
or dumping the wastes en masse would likely minimize the potential impacts
on epipelagic ichthyopl ankton. It should be emphasized, however, that
available information on zooplankton and ichthyoplankton inhabiting the
mesopelagic zone (100 to 1,000 m) is limited.
153
-------
Adult pelagic fishes are less likely to be adversely affected by any
form of disposal of nodule processing wastes. Because of their strong
swimming abilities, pelagic fishes should generally be able to avoid turbid
water areas created by the disposal of such wastes. Experiments conducted
with tunas in captivity have demonstrated that they are able to detect and
avoid areas of high turbidity (Barry 1978). At the highest turbidities
tested, tunas sometimes stopped feeding and occasionally engaged in a
behavior described as "coughing" if they entered the turbid water (Barry
1978). It seems likely that the avoidance of turbid waters by tunas is a
response to the visual properties of the water, and that their cessation of
feeding upon entering turbid water is due to their inability to locate prey
(Barry 1978). Such turbidity-related effects would of course be extremely
localized and short-lived since the residence time of the particulate matter
in the euphotic zone would be relatively short, and it is doubtful that
these far-ranging fishes would spend an appreciable amount of time within
such areas. Barry (1978) reported no ill effects on the captive tunas
during short-term exposure to turbid waters. Similar arguments could be
advanced for the lack of expected turbidity-related effects on other
nektonic species, including the marine mammals (i.e., whales, porpoises,
seals, etc.).
Although marine fishes have been shown to have considerable ability to
regulate most metals in their muscle tissues (Eustace 1974; Hal crow et al.,
1973; Grieg et al., 1976), laboratory investigations indicate that the
uptake of metals in marine fishes is complex, and dependent on fish species
and tissue in addition to the form of the metal. Westerhagen et al. (1980)
found that the liver was the main organ of cadmium accumulation in juvenile
dab (Limanda limanda) and plaice (P1 e u r o n e c t e s p1 at ess a). Cadmium
accumulated at relatively low levels in muscle tissue (2-3 x controls) after
a 96-day exposure to a soluble cadmium concentration of between 5 and 50
ug/1. Although such laboratory experiments may provide information on
potential metal uptake rates, depuration rates, and the fate of cellular
metals, the relationship to potential bi oaccumul ation in the sea is
questionable. In laboratory exposures, organisms are generally exposed to
filtered seawater and a metal in the form of a soluble salt. In such cases,
the metal would exist in solution primarily in ionic form or with a soluble
inorganic ligand. Thus, the potential for direct uptake is considerably
greater than under natural conditions where a metal may occur in a form much
less available for direct uptake (e.g., adsorbed onto particulates). In
addition, most pelagic fish species would spend such a short time in the
presence of these wastes that bioaccumulation would be extremely unlikely.
Adverse impacts of the nodule processing wastes on deep benthic
communities will likely vary depending upon the amount of material deposited
on the sea floor, the dispersal of this material, and the amount and
duration of increased turbidity just above the bottom. These factors will
vary considerably with the disposal method chosen. Empirical relationships
between solids deposition rates and changes in benthic community parameters
are not available, although rough, qualitative impact estimates may be
obtained by comparing predicted deposition rates due to ocean discharges or
dumping with natural sedimentation rates. If the predicted rates are small
relative to natural rates, it may be inferred that the potential for impacts
154
-------
on the benthic communities will also be small. Alternatively, a high
deposition rate of discharged solids relative to background values is
indicative of a substantial impact potential, especially in communities
adapted to naturally low sedimentation rates. It seems probable that the
large, mobile scavengers would be able to avoid burial under a fine "rain"
of particulate matter and that they would be able to evacuate areas of
increased turbidity, if these areas were not too widespread. The area
affected will of course depend on a number of factors, including the
disposal method, the density profile of the water column, ocean currents,
etc., and therefore the affected area is difficult to predict at this time.
Subsurface deposit-feeding animals would probably be affected the least
of any benthic organisms because they are only dependent on the growth of
bacteria beneath the surface of the sediments. Bacterial growth could be
affected if the processing wastes buried the bottom with a sufficiently deep
cover of sediments, but the depth of deposition required for such an effect
is unknown (Jumars 1981).
Suspension feeders and surface deposit feeders would probably be
similarly affected by the deposition of nodule processing rejects on the
ocean floor and by the associated increased turbidity near the bottom. The
former organisms feed on suspended particulate organic matter, while the
latter ingest similar particles after they have settled on the bottom. If
the fine particulate matter in the processing wastes "scavenges" organic
matter from the water (i.e., if organic matter is adsorbed onto its
surface), the particles could be ingested by these animals and provide them
an increased food supply. The suspension feeders are likely adapted to very
low ambient levels of suspensate, however, and their filtering apparatuses
may be clogged if particulate levels are too great. In addition, since
these animals live in an environment where natural sedimentation rates are
on the order of millimeters per thousand years, they may possess only very
limited burrowing abilities and they may be buried if the rate of
sedimentation is too high. Burial under a layer of sediments, even if it is
only a very thin layer, may result in mortality of these organisms (Jumars
1981).
If an area of the deep ocean floor was covered with sediments and the
resident fauna irretrievably buried, it may be a very long time before the
community returns to a "normal" state, since the majority of the meso- and
macrofauna are slow-moving deposit feeders with low dispersal abilities. As
in any environment where the natural community is removed, the first
colonists will probably be those with the highest dispersal ability. It is
impossible to predict recovery times, however, since the generation times of
deep ocean benthic invertebrates are unknown. In addition, there is no way
to predict the direction in which community succession will proceed, since
such perturbations have never been studied in the deep oceans.
Considering that many of the deep ocean benthic organisms feed on
particulate matter, there is a very real possiblity that they will ingest
particulate-bound heavy metals or other potentially toxic substances and
incorporate them into their tissues. While this would provide a starting
point for bioaccumulation in benthic organisms, this is of less consequence
155
-------
to humans than in other areas of the ocean (especially closer to shore)
where the top carnivores may be ingested by humans and bioaccumulation may
represent a health hazard. Hence, bioaccumulation will be discussed in
detail only with regard to continental shelf organisms.
Possible Biological Impacts of the Disposal of Manganese Nodule Processing
Rejects on the Continental Shelves'
As in the deep oceans, the possible biological impacts of the dumping
of wastes resulting from the smelting of manganese nodules would vary
depending upon the size fraction of the wastes. For the purposes of this
discussion, the effects of the disposal of the fine particulate fraction
(clay-size particles) on continental shelf communities will be considered to
be similar to those discussed below for the hydrometal1urgical process
wastes. Dumping of the coarse particulate fraction (sand-size particles)
may cover and kill the resident benthic organisms, although the area
involved would likely be small. Depending upon the conditions in the local
area, slag dumped on the shelves may be buried by natural sedimentation
(which would of course occur much more rapidly than in the deep oceans,
since sedimentation rates on the shelves are much higher), or it may be
swept clear by ambient currents, if they are sufficiently strong. If the
slag is buried by natural sediments, the indigenous soft-substrate benthic
fauna may return to the area. If, however, the slag remains free of
sediments (which would likely occur where the natural substrate had also
been sand-size particles) the slag may or may not be recolonized by the
natural sand-dwelling fauna, depending upon its suitability (particle size,
organic content, etc.) to these organisms. If, as expected, the slag is
relatively inert, leaching of heavy metals or other potentially toxic
constituents would not be expected to occur, and biological uptake of these
materials would be unlikely.
The continental shelf communities impacted by the disposal of
hydrometal 1 urgical process waste slurries and the nature of those impacts
would again be influenced by the method of introducing the wastes into the
ocean. All dumping methods applicable to deep ocean disposal would also be
possible on the outer continental shelves.
In the case of processing wastes introduced directly to the euphotic
zone, the types of impacts on phytopl ankton would likely be much the same
whether the disposal was over the continental shelf or in the deep ocean.
Increases in turbidity would cause decreases in the penetration of sunlight,
and hence decrease phytoplankton photosynthesis. The magnitude of such an
effect would again depend on the method of release of the wastes (e.g., a
pumped discharge into the surface layer would probably result in greater
turbidity than would a large-scale dump of the wastes, which would leave a
smaller residual amount of particulate matter in the upper layers of the
water column). Due to stronger currents, tidal mixing, and possible coastal
upwelling over the shelves, there is a greater potential for these wastes to
remain in suspension in the upper layers of the water column over the
shelves than in the open ocean.
156
-------
In areas where the low availability of nutrients naturally limits
phytoplankton production, or at certain seasons when nutrients may be
limiting, stimulation of phytoplankton production is also a possible effect
of the disposal of manganese nodule processing wastes if the liquid fraction
of these wastes contains either appreciable quantities of dissolved
ammonium, nitrate, silicate, or trace metals. Alterations in the
availability of nutrients can also bring about changes in the species
composition of the phytoplankton community.
As in the open ocean, the disposal of manganese nodule processing
wastes over the continental shelves could have adverse effects on
phytoplankton if such disposal results in increased concentrations of metals
in seawater. As noted above, adverse effects associated with elevated metal
concentrations include reduction in the rate of primary production by
phytoplankton (cf. Knauer and Martin 1972; Patin et al., 1974; Ibragim and
Patin 1976) and alteration in the species composition and succession of
phytoplankton communities (Thomas and Seibert 1977; Huntsman and Sunda
1981). Effects such as these appear to be related to the free metal ion
activity in the water rather than the total metal concentration (Sunda and
Guillard 1976; Canterford and Canterford 1980; Huntsman and Sunda 1981).
For reasons discussed above, a number of factors [e.g., the pH and
alkalinity of the water, the concentration of natural chelators, the
concentration of competing metals, and the presence of adsorptive surfaces
(Sunda et al ., 1978)] affect the activities of free metal ions, and
therefore it is difficult to predict the effect on phytoplankton of the
addition of a given quantity of any of the heavy metals to the euphotic zone
above the continental shelves. Nevertheless, several factors act in concert
to reduce the likelihood of adverse effects on phytoplankton over the
continental shelves.
The first factor is that, in general, waters over the continental
shelves have higher concentrations of particulate matter than waters of the
open ocean. Consequently, there is a greater likelihood that free metal
ions will be adsorbed onto particulate matter in the waters over the
continental shelves. In addition, compared to open ocean waters, waters
nearer the continents may have a relatively high content of natural
chelators due to the higher concentrations of organic matter. Metal ions
there would have a greater chance of being bound by naturally-occurring
organic ligands, which would render them unavailable to the phytoplankton
(Sunda and Guillard 1976). Lastly, there is some evidence that
phytoplankton species which have evolved in and are adapted to
physically-variable environments would, because of their adaptations, be
better able to tolerate any toxic compound than would
morphologically-similar species adapted to more stable environments (Fisher
1977). Such differences may even occur at the intraspecific level, since
Murphy and Belastock (1980) have demonstrated that clones of a single diatom
species which occurred in polluted estuarine environments were less
sensitive to certain organic chemical wastes than were clones of the same
species from neritic and oceanic environments. Such differences in
resistance to chemical stress may be associated with changes in membrane
structure and permeability (Fisher 1977). Even though the aforementioned
157
-------
factors act in concert to minimize the potential adverse effects on
phytoplankton in shelf environments, there is still cause for concern
because the shelf environments are not only more productive, but also
because they are more closely linked with food chains leading directly to
man, with numerous species of importance in commercial and recreational
fisheries.
In areas of the continental shelves shallow enough to support benthic
algal growth, the dumping of processing wastes could have similar effects on
the growth of these algae (i.e., reduced photosynthesis, stimulation or
inhibition of growth, alteration of community species composition and
succession, and burial of both substrate and algae).
Changes in either the level of primary production or the phytoplankton
species composition could cause changes at higher trophic levels, since much
of the secondary production on the continental shelves is ultimately
dependent on phytoplankton for the fixation of carbon. Whereas impacts of
waste discharge on phytoplankton in the deep ocean are likely to be both
extremely localized and short-lived, the greater potential for slower
settling and/or resuspension of the fine particulate matter over the
continental shelves suggests that impacts on phytoplankton associated with
the physical properties of the particulate wastes may not only cover a wider
area, but may persist for a longer time in the waters over the shelves. The
potential for adverse impacts on economically important organisms at higher
trophic levels is also enhanced due to shorter food chains wh.ich tend to
prevail in shelf waters. This is in part due to the larger size of
phytoplankton cells in shelf waters relative to open ocean waters (Parsons
and LeBrasseur 1970). It should be noted, however, that nearshore and shelf
phytoplankton assemblages are naturally adapted to higher levels of
suspended solids. Thus, they may be less sensitive to a given turbidity
increase than open ocean assemblages.
Adverse effects on zooplankton of the disposal of manganese nodule
processing wastes over the continental shelves are similar to those expected
in the open ocean. Zooplankton are generally abundant at all depths above
the continental shelves, however, so there is less potential for minimizing
impacts on these animals by discharging the wastes deep below the euphotic
zone. Once again, dissolved components of the wastes may be directly toxic
to zooplankton, or the fine particulate matter may clog zooplankton
filtering apparatuses, abrade their mouthparts, and/or actually be ingested
by the animals. Zooplankton mortality or reduction in grazing efficiency
may result. As in the case of open ocean disposal of these wastes, the
incorporation of this fine particulate matter into fecal pellets may be a
beneficial effect of zooplankton grazing resulting in increased
sedimentation of particulate matter. Moreover, binding of metals to organic
substances in fecal pellets may reduce the availability to other organisms.
Just as for phytoplankton, adverse effects on zooplankton may have
important ramifications for higher trophic levels, since many are dependent
on the transfer of organic matter, produced by phytoplankton, through the
zooplankton, before it can become available to other animals. Notable
exceptions include those fishes able to feed directly on phytoplankton
158
-------
(e.g., anchovies in areas of coastal upwelling) and certain filter-feeding
benthic organisms (e.g., clams in shallow regions of the shelves). Adverse
effects on zooplankton over the continental shelves may be more widespread
and persistent than in the deep ocean, since there is a greater potential
for slower settling and/or resuspension of the fine particulate matter, due
to stronger currents, tidal mixing, and possible coastal upwelling over the
shelves.
The possibility of adverse effects of the disposal of manganese nodule
processing wastes on ichthyoplankton is especially important in the
continental shelf environment, because most commercial fish species inhabit
shelf areas. In addition to the potential adverse effects on planktonic
fish eggs and larvae mentioned earlier (direct toxic effects, interference
with feeding, indirect food-chain effects), an additional consideration is
the potential impact on those fish species which lay their eggs on the
bottom. Demersal eggs could be buried and killed by the dumping of fine
particulate matter on the sea floor over the continental shelves. Rosenthal
(1971) demonstrated, for instance, that suspensions of "red mud," the waste
product from the production of aluminum from bauxite, retarded the rate of
development of herring embryos and increased their frequency of embryonic
malformations. Herring eggs are demersal, and Rosenthal (1971) reported
that red mud particles adhered to the chorion of these eggs, possibly
interfering with gaseous and other material exchanges between the eggs and
the surrounding medium. It is conceivable that manganese nodule processing
wastes might have similar effects on demersal fish eggs.
Although pelagic fish species inhabiting the continental shelves are
also strong swimmers capable of avoiding turbid water areas created by the
disposal of manganese nodule processing wastes, they are generally not as
wide-ranging as the oceanic pelagic fishes. They may be more closely
associated with certain topographic features (e.g., the shelf break, rocky
outcrops, favored feeding and/or spawning areas) and therefore more
susceptible to adverse impacts (e.g., interference with feeding behavior,
bioaccumulation of heavy metals and/or other potentially toxic constituents
of the wastes) attributable to disposal of these wastes in a specific area.
As in the deep sea, the adverse impacts of the nodule processing wastes
on continental shelf benthic communities will likely vary depending upon the
amount of material deposited on the sea floor, the dispersal of this
material, and the amount and duration of increased turbidity just above the
bottom. These factors will vary considerably with the disposal method
chosen. Regardless of the disposal method, however, the fact that the water
column is .so much shallower over the shelves than in the deep sea (a factor
of 10 to 100 times shallower) means that the particulate wastes are likely
to settle out of the water more quickly and not be as dispersed laterally as
in the deep sea. An additional factor that must be considered, however, is
that the ambient currents in some areas of the continental shelves may be of
sufficient magnitude to keep these particulate wastes in suspension and
transport them great distances before deposition occurs. In certain areas
of the continental shelves, sediments may be transported across the shelf,
deposited in the vicinity of the shelf break, and periodically sloughed off
as turbidity currents into the deep sea. Hence, particulate matter
deposited on the shelves may eventually end up on the deep ocean floor.
159
-------
Large, mobile organisms, such as demersal fishes and crabs, would
likely be able to avoid burial under settling particulate matter and
evacuate areas of increased turbidity, provided that these areas were not
too widespread.
The types of potential impacts on shelf benthic communities are similar
to those discussed above for the deep-sea benthos, but the significance of a
given impact is likely to be greater. The greater concern over potential
adverse impacts of the dumping of manganese nodule processing rejects on
benthic communities on the continental shelves is because many of the
affected organisms are either currently or potentially in food chains
leading directly to humans.
The consequences of blanketing the sea floor over the continental
shelves with a layer of fine particulate matter will depend upon the rate of
deposition and the thickness of the deposit. While it is difficult to make
accurate predictions, it is probably safe to predict that shelf-dwelling
organisms would likely be less affected by a given thickness of sediment
cover than would deep-sea organisms. The shelf organisms live in an
environment with much higher ambient sedimentation rates, and consequently
they should have better burrowing abilities and should be less likely to be
irretrievably buried. The ability to stay at the sediment-water interface
may not guarantee survival, however, especially for surface deposit feeders.
These organisms are dependent on ingestion of organic matter in the
sediments, and a layer of primarily inorganic, waste-derived sediments may
not contain adequate organic matter for their nourishment.
There is a very real possibility that suspension feeders and surface
deposit feeders inhabiting the continental shelves would ingest particulate
processing wastes if such wastes were discharged in their environment. It
is also possible that particul ate-bound heavy metals or other potentially
toxic substances ingested by these organisms could be incorporated into
their tissues, and thus provide a starting point for bioaccumulation through
benthic food chains. Considering that many of the larger organisms on the
continental shelves (e.g., demersal fishes and crabs, including commercially
valuable species) ingest benthic suspension feeders and deposit feeders,
there is concern that bioaccumulation in these organisms may represent a
health hazard for humans.
If an area of the continental shelf was covered with rejects and the
resident fauna irretrievably buried, recovery of the community to a "normal"
state would likely proceed much more quickly than in the deep sea. Benthic
invertebrates on the continental shelf, in particular, have excellent
dispersal abilities, since many have planktonic larvae. While the first
colonists are likely to be those with the highest dispersal ability, the
direction of succession is difficult to predict, especially because the
suitability of sediments for colonization by benthic invertebrates is a
function of the grain size of the sediments, which in this case remains
unknown.
160
-------
Recovery potential of marine communities has been evaluated following
both natural and anthropogenic stresses. The available evidence indicates
that even in cases of drastically disturbed nearshore sediments there is
generally a relatively rapid recolonization (Rosenberg 1972; Dauer and Simon
1976). In a comprehensive study in Monterey Bay, Oliver et al. (1977) found
that successional patterns following disturbance were dependent upon the
nature of adjacent undisturbed communities. In situations where large
motile organisms (e.g., peracarid crustaceans) were abundant, these groups
generally constituted the initial colonizers in addition to opportunistic
polychaetes (i.e., those with short generation times and ability to change
from larval dispersal to brooding). If large motile organisms were not
abundant, opportunistic polychaetes provided the primary initial
colonization. The second phase was characterized by a return of the normal,
pre-disturbance community. In general, early colonizers do not reach a
stable community dominance that prevents a return of the normal indigenous
species. Continued dominance has been observed, however, in cases of
repeated (annual) defaunation of benthic communities (Santos and Simon
1980).
Documented cases of faunal recovery have usually been associated with
disturbances such as oil spills, dredge spoil deposition, deoxygenation, and
natural turbidity flows. As such, the recovery processes have occurred in
natural sediments, usually containing from 1 to 10 percent organic matter.
Many of the initial opportunistic colonizers of disturbed sediments are
deposit feeders (e.g., the polychaete Capitel1 a capitata). These organisms
ingest deposited sediment, either at or below the sediment surface, and
utilize organic matter contained therein as food. If a substantial layer of
reject material were deposited on the bottom, colonization processes may be
different than those observed in natural sediments because of the inorganic
nature of reject material. The lack of organic matter would limit initial
colonization to suspension feeders or surface detritus feeders. These
organisms could utilize naturally occurring near-bottom organic matter,
either as newly deposited material or as a suspension.
As noted above, the possibility of bioaccumulation of potentially toxic
metals is of concern for continental shelf organisms, since many are in food
chains leading to humans. Accumulation of the metals may occur through
direct uptake of the dissolved metals, ingestion of contaminated
particulates, or through ingestion of other contaminated organisms. The
biological importance of a trace metal is not only dependent upon its
physical/chemical state upon discharge, but also upon the ultimate solute
concentration in seawater, which is a function of sorption-desorption,
dissolution-precipitation, and metal-ligand associations following
discharge.
It was indicated above that iron/manganese oxides are an important sink
for metals in the marine environment, and that the metals were also often
bound to organic or inorganic particulate matter. Luoma and Jenne (1977)
demonstrated that the bioavail abi 1 ity of several metals to deposit-feeding
clams is inversely proportional to the sediment-water distribution
coefficient. Thus, sinks with a high rate of sediment-to-water desorption
resulted in a high bioaccumulation of metals. It is interesting to note
161
-------
that the rank ordering of sinks relative to bioaccumulation potential varied
according to the metal tested. For silver, the concentration factor in clam
tissue was about an order of magnitude higher from manganese oxide than from
organic particulates. The opposite situation was found for zinc. Luoma and
Jenne (1977) also found that the rate of bioaccumulation resulting from
ingestion of solids with adsorbed metals was considerably slower than the
uptake of soluble forms. The authors concluded that short-term exposures
(less than several days) to certain sediment-bound metals (e.g., hydrous
oxide bound Zn and Co) would result in negligible bioaccumulation in the
clam.
Neff et al. (1978) indicated that bulk metal analyses of solids are not
useful in predicting bioavai1abi1ity of sediment-adsorbed metals. In a
series of 136 metal-species-sediment exposures of marine organisms to
natural sediments, significant accumulation of metals occurred in only 36
cases (26.5 percent). The observed cases of bioaccumulation, many of which
were quantitatively marginal, could not be correlated with the form of the
metal present in the sediments.
The physiological state of an organism can also strongly affect the
degree of tissue contamination by metals. Although metal concentrations
have been demonstrated to be related to body size, the relationships vary
among species and metals (Cross et al. , 1973; Bryan and Uysal 1978; Boyden
1977). Moreover, Strong and Luoma (1981) have demonstrated that the
relationship of body size to metal concentration may differ among
populations of a single species and also with season. Other environmental
variables affecting metal uptake* and accumulation include salinity, water
temperature, and.the presence of other metals (Phillips 1976).
A wide variety of marine organisms has been shown to accumulate metals
in body tissues when exposed to contaminated water or sediments. It is also
apparent that accumulated metals may be transferred upward among trophic
levels (e.g., from phytoplankton to zooplankton). It is important to note,
however, that the occurrence of bioaccumulation of a potentially toxic
substance does not necessarily mean that biomagnification will occur. The
potential for biomagnification is an important concern since its occurrence
can result in high concentrations of potentially toxic substances in higher
trophic level organisms (e.g., fishes) which are used as food by man.
Biomagnification has been documented for some high molecular weight
organic compounds (e.g., DDT) and for methylmercury; however, there is
currently little evidence for biomagnification of inorganic forms of metals
(Bryan 1979). Substances displaying evidence of biomagnification are
lipophilic and are stored in the fat deposits of an organism. Such tissues
are relatively inert and enable only limited active metabolism and/or
excretion of the substance. Inorganic substances such as non-methylated
metals do not have lipophilic tendencies and are much more available for
active regulation by marine organisms. In general, the ability of organisms
to regulate metals increases in more taxonomically advanced species (e.g.,
higher in fishes than in crustaceans; Bryan 1979). In addition, marine
organisms generally have more ability to regulate metals important as
micronutrients (e.g., copper and zinc) than for non-essential metals (e.g.,
162
-------
cadmium and lead). The processes of metal regulation not only vary
according to the metal and species, but also according to the organism
tissues. Based on the low tissue metal levels in many contaminated
environments, marine fishes and some invertebrates apparently have a high
capacity to regulate metal concentrations in their muscle tissue. The
ability of more advanced predatory forms to regulate tissue metal
concentrations is an important factor in explaining the apparent absence of
biomagnification of inorganic metals.
A wide variety of invertebrate and vertebrate marine organisms have
been shown to detoxify and sequester assimilated metals (Roesijadi 1981).
The role of metallothionein-type proteins in the detoxification mechanism
has been widely studied. It appears that these low molecular weight
proteins play an important role in sequestering potentially toxic metals
(e.g., Cd, Hg, and Ag) in addition to regulating the metabolism of essential
trace metals such as zinc and copper. Metallothionein production in an
organism can be induced by exposure to non-essential metals such as cadmium,
and thus forms an important role in the development of tolerances to
potentially toxic metals. Marine organisms may also be able to genetically
adapt to increased environmental metal concentrations. In a study of the
polychaete Nereis diversicolor, Bryan and Hummerstone (1973) found that
worms living in contaminated sediments were more resistant to zinc than
control worms. The tolerance was apparently genetically determined and was
probably associated with reduced permeability and more efficient excretion.
Possible Biological Impacts of the Disposal of Manganese Nodule Processing
Rejects in Nearshore Area's
Impacts of the dumping in nearshore areas of wastes resulting from the
smelting of manganese nodules would likely be much the same as those already
described for the dumping of such wastes on the continental shelves. Hence,
for the purposes of this discussion, the effects of the disposal of the fine
particulate fraction (clay-size particles) on nearshore communities will be
considered to be similar to those discussed below for the hydrometallurgical
process wastes. Recolonization of areas covered by the coarse particulate
fracti'on (sand-size particles) will depend on burial of these wastes by
natural sediments, the suitability (particle size, organic content, etc.) of
these waste sediments to natural sand-dwelling organisms, and/or the
potential toxicity of heavy metals or other constituents of the wastes which
may leach into the water.
The disposal of hydrometallurgi cal process waste slurries in the
nearshore environment would likely involve the use of submarine outfalls.
The impact of this disposal method on nearshore ecosystems would depend on
the depth of discharge, the local wave and current regime, the physical and
chemical nature of the wastes, and on the nature of the biological habitats
in the area. One of the most important considerations with regard to
predicting the effect of this disposal method on biological communities is
the depth of the outfall. Solids discharged from outfalls in waters less
than approximately 30 m can be subjected to wave induced resuspension and
reintroduction into the euphotic zone. Whether or not this method would be
successful at keeping the resultant turbid water at depth is dependent on
163
-------
the other aforementioned factors (i.e., hydrography, density structure,
currents, physical nature of the wastes).
If the processing wastes were discharged directly into the euphotic
zone, or, conversely, if they were discharged below this zone and advected
into it by other processes (e.g., tides, currents, etc.), impacts on
phytoplankton would likely be much the same as those described above for
phytoplankton in the open ocean or over the continental shelves. Increases
in turbidity within the euphotic zone would cause decreases in the
penetration of sunlight, and hence decrease phytoplankton photosynthesis.
Stimulation of phytoplankton production is also a possible effect of
the disposal of manganese nodule processing wastes if the liquid fraction of
these wastes contains either appreciable quantities of dissolved ammonium,
nitrate, silicate, or trace metals. Alterations in the availability of
nutrients can also bring about changes in the species composition of the
phytoplankton community.
Phytoplankton production may be inhibited and/or phytoplankton species
composition may be altered if free metal ions are present in high enough
concentrations. As discussed above in regard to potential effects on
continental shelf communities, the higher concentrations of particulate
matter and of organic substances in the water nearshore may render any
introduced free metal ions unavailable to phytoplankton. These ions may be
expected to be adsorbed onto particulates or bound to naturally-occurring
organic ligands much more frequently nearshore than in the open ocean, and
perhaps even more frequently than over the continental shelves. In
addition, nearshore algal species may be less sensitive to chemical stress
than those algal species inhabiting more stable, less stressed environments
offshore. As for the shelf environments, there is still cause for concern,
even in the presence of these mitigating factors, because the nearshore
environments are not only more productive, but also because they are more
closely linked with food chains leading directly to humans, with numerous
species of commercial and recreational importance. Any impact on
phytoplankton related to the presence of dissolved substances in the waste
slurry would probably be minimized by disposal below the euphotic zone
(i.e., below 100 m), since appreciable dilution would likely occur before
these substances could enter the euphotic zone by such processes as
diffusion or upwelling.
Similar effects (i.e., reduced photosynthesis, stimulation or
inhibition of growth, burial of both substrate and benthic plants) may occur
if the wastes enter the euphotic zone in nearshore areas where benthic
plants (i.e., kelps, sea grasses, etc.) are found. Such impacts could have
important ramifications because certain benthic plants, notably kelps, are
important in structuring the environment and making it suitable for
habitation by a large number of associated organisms, while other plants
represent food resources for certain animals (e.g., turtle grass is an
important food for marine turtles).
Changes in either the level of primary production or the species
composition of the various nearshore plant communities could cause changes
164
-------
at higher trophic levels. Whereas impacts of waste discharge on primary
production in the open ocean and over the continental shelves are likely to
be temporary because the wastes will eventually settle out of the water
column and remain below the euphotic zone, impacts on primary production
nearshore are likely to be more long-lasting, since even if the wastes
settle onto the bottom, there will be a much greater likelihood of
resuspension and reentry into the euphotic zone. In addition, burial of
hard substrates will likely make the bottom unsuitable for the growth of
most macroalgae, which must be able to attach to a hard substrate to
establish themselves in an area. Just as on the continental shelves, the
potential for adverse impacts on economically-important organisms at higher
trophic levels is also enhanced nearshore due to the shorter food chains
which tend to prevail there (Parsons and LeBrasseur 1970).
Adverse effects on zooplankton due to the disposal of manganese nodule
processing rejects in nearshore waters are similar to those expected in the
open ocean and over the continental shelves. Just as for phytoplankton,
adverse effects on zooplankton may have important ramifications for higher
trophic levels, since many are dependent on the transfer of organic matter,
produced by phytoplankton, through the zooplankton, before it can become
available to other animals. This is not as important in nearshore
environments as it is in open ocean or outer continental shelf environments,
however, since a significant fraction of the nearshore primary production is
often performed by benthic plants. Adverse effects on zooplankton in
nearshore environments may be more persistent because of the greater
potential for retention and resuspension of these wastes in nearshore
environments.
The possibility of adverse effects on ichthyoplankton attributable to
the disposal of processing wastes is especially important in the nearshore
environment, because many fish species utilize these areas as spawning and
nursery grounds. In addition to the potential adverse effects on planktonic
fish eggs and larvae mentioned earlier (direct toxic effects, interference
with feeding, indirect food-chain effects), an additional consideration is
the potential impact on those fish species which lay their eggs on the
bottom, as discussed above with regard to continental shelf environments.
Demersal eggs could be buried and killed by the dumping of fine particulate
matter on the bottom in nearshore areas.
Although pelagic fish species inhabiting the nearshore areas are also
strong swimmers capable of avoiding turbid water areas created by the
disposal of manganese nodule processing wastes, they are generally not as
wide-ranging as the oceanic pelagic fishes, and they may be even more
closely associated with certain topographic features (e.g., coral reefs,
rocky outcrops, favored feeding and/or spawning areas) than are the shelf
species, and therefore more susceptible to adverse impacts (e.g.,
interference with feeding behavior, bioaccumulation of heavy metals and/or
other potentially toxic constituents of the wastes) attributable to disposal
of these wastes in a specific area.
As in the deep sea and on the continental shelves, the adverse impacts
of the nodule processing wastes on nearshore benthic communities will likely
165
-------
vary depending upon the amount of material deposited on the bottom, the
dispersal of this material, and the amount and duration of increased
turbidity just above the bottom. These factors will vary with the depth of
the waste discharge. Other important factors include the local hydrography,
the density structure of the water column, currents, and the physical nature
of the wastes.
Ambient currents in some nearshore areas may be of sufficient magnitude
to keep these particulate wastes in suspension and transport them great
distances before deposition occurs, even in cases where the outfall
discharge is well below the surface (cf. Waldichuk and Buchanan 1980). This
high waste dispersion potential in the nearshore environment has several
important implications related to environmental considerations. In some
areas there may be a potential for shoreward transport of discharged wastes,
resulting in potential impacts on sensitive or important nearshore habitats
(e.g., kelp beds). Thus, the potential for transport of the waste either
before or after initial deposition must be considered. It should also be
noted, however, that relatively shallow nearshore waters enable much more
reliable post-discharge monitoring of waste dispersal and any environmental
effects. The basic environmental consideration related to effects on
benthos and fishes would be similar to those identified for shelf areas.
However, the potential for bioaccumulation of metals is an especially
important consideration in nearshore areas because of the occurrence of many
important recreational fisheries in addition to commercial fisheries.
Certain bervthic habitats unique to the nearshore area (i.e., kelp beds,
sea grass beds, coral reefs, intertidal areas) are particularly susceptible
to impacts either from increased turbidity or from burial of the substrate
by processing wastes. Possible effects on kelp beds, sea grass beds, and
other benthic plant communities were mentioned previously in the discussion
of impacts on primary productivity. Coral reefs and intertidal habitats
(especially on rocky substrates) are of concern because many of the animals
in each are suspension feeders, and because alterations in the substrate in
each area may cause irreparable destruction of these habitats.
SIGNIFICANT ENVIRONMENTAL CONSIDERATIONS
Environmental considerations identified for the various marine disposal
alternatives are listed in Table 32. The diversity of potential impacts
involves organisms of essentially every trophic level in every marine
habitat. For the sake of discussion, however, and to facilitate estimation
of the relative significance of the various impacts for each of the disposal
options, the 26 specific potential impacts listed in Table 32 were grouped
into the following general categories:
1. Effects on primary production
2. Direct toxic effects
3. Effects on behavior and feeding of marine organisms
4. Bioaccumulation effects
166
-------
TABLE 32. A LIST OF ENVIRONMENTAL CONSIDERATIONS RELATED TO
MARINE DISPOSAL OF MANGANESE NODULE PROCESSING WASTES AND REJECTS
I. Effects
1.
2.
3.
4.
II. Direct
5.
6.
7.
8.
9.
10.
11.
III. Effects
12.
13.
14.
15.
16.
17.
on primary production
Decrease in photosynthesis by phytoplankton due to
Decrease in photosynthesis by benthic flora due to
Stimulation of production by phytoplankton due to
Stimulation of production by benthic flora due to
toxic effects
Direct toxicity to phytoplankton
Direct toxicity to benthic flora
Direct toxicity to zooplankton
Direct toxicity to ichthyoplankton
Direct toxicity to pelagic fishes
Direct toxicity to demersal fishes
Direct toxicity to benthic fauna
on behavior and feeding of marine organisms
Interference with grazing by zooplankton
Interference with feeding by ichthyoplankton
Interference with pelagic fish feeding behavior
increased turbidi
increased turbidi
ty
ty
increased nutrients
increased nutrients
Interference with feeding behavior of benthos and demersal fishes
Interference with migration patterns
Interference with reproductive behavior
IV. Bioaccumulation effects
18.
19.
20.
21.
V. Effects
22.
23.
Bioaccumulation of potentially toxic substances in
Bioaccumulation of potentially toxic substances in
Bioaccumulation of potentially toxic substances in
Bioaccumulation of potentially toxic substances in
of alteration in benthic substrate
phytoplankton
zooplankton
fishes
benthic fauna
Effects on benthos due to alteration in substrate or smothering
Effects of substrate modification on demersal fish
distribution
VI. Inter-trophic effects
24. Higher trophic level effects of impacts on phytoplankton
25. Higher trophic level effects of impacts on zooplankton
26. Higher trophic level effects of impacts on benthic fauna
167
-------
5. Effects of alteration in benthic substrate
6. Higher trophic level effects.
To evaluate the potential disposal options from an environmental
perspective, it is important to consider how these options, in conjunction
with environmental factors, influence the relative significance of the
environmental considerations identified in Table 32. The various disposal
options are summarized in Table 33. The magnitude of each potential impact
may be expected to vary with the method of disposal. Effects on primary
productivity, for instance, may be considerably reduced by those disposal
methods which introduce the processing wastes into the ocean at depths below
the euphotic zone (i.e., subsurface dispersal), or which minimize the
residence time of the wastes within the euphotic zone (i.e., surface dump).
Direct toxic effects, which are normally associated with elevated
concentrations of dissolved chemical substances, may be mitigated by
disposal methods which result in greater dispersion of the wastes.
Interference with the feeding of pelagic organisms (e.g., zooplankton,
ichthyoplankton, pelagic fishes) would be lessened by the introduction of
wastes below the euphotic zone or by minimizing the residence time of the
wastes within the upper layers of the ocean. Interference with the feeding
of benthic organisms may be minimized by disposal methods resulting in the
greatest dispersion of the wastes, which would reduce both the thickness of
waste sediment deposits and the turbidity above the bottom.
The possibility of bioaccumulation is of concern in all of the disposal
scenarios, but it is certainly of less significance when the subject
organisms are deep-sea benthos, rather than continental shelf or nearshore
species potentially in food chains leading to humans. Biological impacts
associated with changes in the benthic substrate would be minimized by
disposal methods which result in the greatest dispersal of the wastes (i.e.,
open-ocean dispersal vs. a nearshore dump), the least change in the prior
substrate (i.e., disposing of the wastes in areas already having a fine
particulate substrate), or the lack of appreciable deposition due to ambient
currents. Effects on higher trophic levels due to impacts on lower trophic
levels are potentially of importance in all environments, but as in the case
of bioaccumulation, the greatest concern is associated with effects on those
higher trophic level organisms utilized by humans. Such effects will be
more likely where food chains are short (e.g., coastal areas) rather than in
areas where food chains are long (e.g., open ocean areas) (cf. Parsons and
LeBrasseur 1970).
The relative significance of each potential environmental effect is
dependent upon four basic considerations:
• The severity of the effect (e.g., sublethal or lethal)
• The spatial extent of the effect
• The duration of the effect
168
-------
TABLE 33. DISPOSAL OPTIONS CONSIDERED FOR EVALUATION OF
POTENTIAL EFFECTS OF REJECT DISPOSAL
Disposal Zone
Disposal Method
Inner shelf
Mid shelf
Deep ocean
outfall
surface dumping
surface dumping
surface dispersal
subsurface dispersal
surface dumping
surface dispersal
subsurface dispersal
169
-------
• Potential involvement of commercial or recreational species.
Each of these considerations is in turn dependent upon characteristics of
the exposed organisms, the receiving water body, and the disposal method.
The overall severity of an effect may range from short-term
physiological responses (e.g., change in respiration rate) to death. It is
dependent upon the physi cal/chemi cal characteristics of the waste,
sensitivity of indigenous organisms to the waste, and exposure conditions
(e.g., time and concentration). The greater sensitivity of open ocean
communities to impacts on primary production reflects both the greater
sensitivity to chemical stress of the phytopl ankton species found in such
environments, and the lower ambient concentrations of natural organic
ligands, which could complex with potentially inhibitory free metal ions.
Naturally, disposal options which result in the wastes being introduced
below the euphotic zone should minimize the potential impacts on primary
production. The potentially greater sensitivity of open-ocean organisms to
direct toxic effects also reflects adaptation to an environment with few
prior chemical stresses. However, it should be emphasized that the response
of open-ocean communities to anthropogenic stresses are not well understood
and would require considerable further study before definitive estimates of
potential effects could be made.
Effects on feeding of marine organisms are likely to be greater in the
open ocean than inshore because open-ocean organisms typically feed in
waters with very low levels of suspended particulate matter. Effects on
feeding are also expected to be greater for epi pelagic organisms than for
those lower in the water column because both filter feeders and
visually-orienting predators are more prevalent near the surface. Deep-sea
benthic organisms are likely more sensitive to alterations in the benthic
substrate than benthic organisms nearshore because they have evolved in an
environment with extremely slow rates of sedimentation. Disposal options
which result in greater dispersion of the wastes will tend to mitigate this
effect. Finally, higher trophic level effects are most likely for nearshore
and shelf organisms because higher level predators of the open ocean are not
only more wide-ranging than those inshore, but they are also, in general,
more trophic steps removed from the primary producers. Once again, disposal
of the wastes below the euphotic zone may tend to minimize effects on higher
trophic levels.
The spatial extent of an effect is dependent upon the disposal method
(e.g., dispersal or dump) and the distributional characteristics of affected
organisms. Plankton, by their very nature, are transient inhabitants of a
particular area and any localized effects would generally be ameliorated by
dispersion of the affected organisms. In general, the potential spatial
effects are greater for the disposal options involving dispersion when
compared with dumping. However, evaluation of the spatial extent of effects
should also involve a consideration of the dilution necessary to cause no
adverse effects. Hence, it may be appropriate to use a combination of
disposal option (e.g., slow dispersion from a barge) and naturally high
ambient dispersal mechanisms (i.e., currents) to reduce the potential for
effects although the waste would be distributed over a large area. Contrary
170
-------
to the other environmental considerations, effects of a change in benthic
substrate will cover the least area when the wastes descend quickly to the
ocean floor (e.g., in shallow water nearshore, or during a surface dump).
In cases where the wastes are dispersed upon disposal, the area affected
would be greater and the depositional rate per unit area would be less,
especially in deep waters of the open ocean. The low depositional rates
would probably result in a concomitant decrease in the potential impacts on
benthic organisms. Higher trophic level effects are relatively unlikely in
the open ocean, and hence would not cover a large area. If such effects
were to occur over the shelf or nearshore, they would cover a larger area if
the wastes were dispersed at the surface than they would if the wastes were
discharged at depth.
The duration of an effect is dependent upon the severity of the effect
and the recovery potential of the exposed population. Sublethal responses
such as changes in primary production or feeding behavior would most likely
be extremely transitory (e.g., hours to days) in plankton populations, and
would most likely exist only during the limited exposure period prior to
waste settling. Even lethal effects on plankton communities would most
likely be of limited duration due to rapid mixing and short generation
times. Alternatively, if significant bioaccumulation of metals occurred in
benthic organisms, the effect would probably be of long duration (e.g.,
months to years) because of continued exposure to the contaminated
sediments. For effects of substrate alteration or smothering of benthos,
the effect duration would depend upon reproductive and dispersal
characteristics of the organisms. Motile species or organisms having high
larval dispersal mechanisms may be able to rapidly repopulate an affected
area, while recovery of sessile organisms with limited dispersal
capabilities would be considerably slower.
For all disposal options, the involvement of commercial or recreational
species is lowest in cases of open-ocean disposal, since there are very few
species of economic importance in such environments. Most oceanic fisheries
are directed at large, wide-ranging species (e.g., tunas, billfishes,
whales, etc.) and the only significant impact on such species might be
temporary interference with feeding behavior, and even this is of far less
concern than for commercial or recreational species over the shelf or
nearshore, since the pelagic species should be able to avoid turbid water
areas. Impacts on primary production are only of commercial or recreational
importance nearshore where some benthic macrophytes (e.g., kelps, other
seaweeds) are routinely harvested. Direct toxic effects on commercial or
recreational species may occur over the shelf, but they would be more likely
nearshore where dispersion of the wastes may be less pronounced. The
feeding of commercial or recreational species may be affected in both
nearshore and shelf environments, but in each case, the effects may be
greater if the wastes are dispersed near the surface. Bioaccumulation in
commercial or recreational species may also occur both over the shelf and
nearshore, but benthic and demersal organisms, the most likely to
bioaccumulate potentially toxic substances, would be subjected to greater
concentrations in shallow water nearshore or when wastes are dumped from the
surface over the shelf. Effects of a change in benthic substrate on
commercial or recreational species would also be favored by either
171
-------
shallow-water discharge or a surface dump over the shelf. Higher trophic
level effects would again be more prevalent if the wastes were dispersed in
the euphotic zone than below it.
Based on the aforementioned considerations, the generic categories of
effects may be grouped according to their relative significance. Effects of
benthic substrate alteration and bioaccumul ation have the highest relative
significance. This is because these potential effects of rejects may be
lethal, occur over an extensive area, be relatively long lasting, and
involve commercial/recreational species. Within the general category of
bioaccumulation, however, the relative significance varies considerably
according to biotic group. For several groups the relative order of
significance of bioaccumulation from highest to lowest, would be: demersal
fishes, benthic invertebrates, pelagic fishes, zooplankton, and
phytoplankton.
Direct toxicity and effects on feeding and behavior would have an
intermediate level of significance. The potential for toxic effects on most
biotic groups would be limited because of short exposure times, high
dilution rates (for most disposal options) and the possibility of limited
availability of toxic substances in the wastes. Potential toxic effects
would probably be lowest for zooplankton and pelagic fishes. Potential
toxicity of phytoplankton would be of greater significance because of metals
contained in reject material (although their availability as soluble forms
is currently unknown) and the sensitivity of phytoplankton to metal toxicity
(compared to other groups). Toxicity to benthic organisms is of
intermediate significance because of the potential for extended contact
with, or ingestion of, waste material.
Effects on primary production and intertrophic effects have the lowest
relative significance among the generic environmental considerations.
Effects on primary production would be of short duration and spatially
limited. Because of the relatively low significance of effects on plankton,
higher trophic level effects resulting from plankton impacts would also have
a low significance. The transitory nature of impacts on plankton would have
a minimal potential for affecting consumers unless such effects were
extremely widespread.
ENVIRONMENTAL CONSIDERATIONS FOR REPRESENTATIVE DISPOSAL AREAS
Biological and oceanographic conditions important in the consideration
of environmental effects of reject disposal in representative disposal areas
are reviewed in Appendix D. The following section provides a summary of the
major environmental considerations for each representative area.
Western Gulf of Mexico
The outer continental shelf of the western Gulf of Mexico includes a
number of offshore banks and coral reefs which should be considered in the
selection of potential manganese nodule processing waste disposal sites. As
described previously, corals on these reefs may be near the environmental
limits of existence and vulnerable to any anthropogenic stresses. These
172
-------
reefs and banks also provide important habitat for demersal snappers which
support local fisheries. There have also been suggestions that potentially
commercial stocks of tilefish and yellowedge grouper exist on the outer
continental shelf of the western Gulf of Mexico, and that future fisheries
may develop to harvest these stocks. The open waters of the Gulf of Mexico
are typical of tropical open ocean waters elsewhere (i.e., low primary
productivity, low productivity of higher trophic levels, and low benthic
biomass). While there are currently no substantial pelagic fisheries in the
open waters of the western Gulf of Mexico, it is possible that a fishery for
tuna could develop over the continental slope.
Hawaii
Nearshore habitats on the island of Hawaii vary considerably between
the windward and leeward coasts. Along the Kona (leeward) coast, there are
extensive coral reefs, while on the windward coast near Hilo, there is very
little coral growth. Coral reefs are especially susceptible to
environmental impacts associated with high turbidity and/or sediment
deposition, and there have been suggestions that the coral reefs north of
Keahole Point on the leeward coast are already stressed by turbid water
conditions. Although the insular shelf around the island of Hawaii is very
narrow, it nevertheless has a number of characteristics which should be
considered in selecting a potential site for the disposal of manganese
nodule processing wastes. Both Hilo and Kona are important centers of
commercial fishing, and most of the Hawaiian fisheries are directed at
pelagic species within 32 km of the coast. The tuna fishery near the edge
of the shelf is especially notable. In areas with a hard benthic substrate,
bottom fisheries are important. In addition, potential fisheries for both
sharks and shrimps may develop around the island of Hawaii in the future.
Precious corals grow in certain areas at depths greater than 100 m around
the island, and are commercially harvested. The shelf waters also represent
important habitat for the humpback whales which overwinter there. Open
ocean areas far offshore of the Hawaiian islands are also typical of
tropical open ocean waters elsewhere (i.e., low primary productivity, low
productivity of higher trophic levels, and low benthic biomass). The only
pelagic fisheries of note are for tuna, but these are not localized in any
specific area.
Pacific Northwest
Certain characteristics of the Pacific Northwest nearshore zone should
be taken into account in selecting manganese nodule waste disposal sites in
this region. Rocky coastlines of the Pacific Northwest provide important
habitat for various marine plants and animals, many of which could be
adversely affected by increased turbidity and sedimentation to be expected
with nearshore disposal of these wastes. Several marine mammal species are
known to frequent the nearshore areas. Permanent residents include Stellar
sea lions and sea otters, while California gray whales pass through the area
on their annual migrations between the Bering Sea and Baja California. One
interesting characteristic of the benthic environment nearshore is that from
the shoreline to a distance of approximately 20 km from shore, and between
depths of 0-80 m, the benthic substrate consists of 100 percent sand-size
173
-------
particles. This reflects the high wave energy in the overlying waters,
especially during winter storms, and suggests that manganese nodule
processing wastes, disposed of in this region, would be subject to
resuspension. Important nearshore fisheries include commercial fisheries
for salmon and Dungeness crab, and recreational fisheries for salmon.
Important characteristics of the outer continental shelf of the Pacific
Northwest should also be taken into account in selecting potential manganese
nodule waste disposal sites in this region. Of particular importance is the
fact that the region is characterized by coastal upwelling during periods of
northerly winds in summer. Deep water over the outer shelf moves inshore
and toward the surface to replace surface water advected offshore. This
inshore movement of water could result in the shoreward transport of
manganese nodule processing wastes if they were disposed of over the outer
continental shelf. Another consequence of the seasonal coastal upwelling in
this region is the enhancement of primary production over the shelf, which
in turn supports enhanced production at higher trophic levels. One result
of this is that the shelf break area is highly productive, and the
macroepibenthos and demersal fishes there are particularly abundant.
Consequently, there is an important multispecies groundfish fishery over the
outer continental shelf and upper continental slope (depths of 30-1,500 m),
and a developing fishery for pink shrimp at depths of 91-183 m. There is
also interest in the region for further expansion of the fisheries to
harvest both pelagic and demersal species which are currently underutilized.
The disposal of manganese nodule processing wastes over the outer
continental shelf could adversely affect both the existing and potential
fisheries of the region, especially for those species (e.g., Pacific
halibut, Pacific cod) with demersal eggs, a stage in the life cycle
particularly vulnerable to the effects of sediment deposition.
Consideration should therefore be given to disposing of these wastes in a
manner which will not adversely affect important Pacific Northwest fishery
resources.
Open-ocean environments beyond the continental shelf and slope of the
Pacific Northwest are also characterized by relatively low primary
productivity and low productivity at higher trophic levels. The only
pelagic fishery of note is the troll fishery for albacore, but it should be
noted that this is a seasonal fishery dependent on warm water temperatures,
and that it only develops in some years. The open ocean waters do provide
important habitat for salmon, but there is currently no open ocean fishery
for these fishes.
The importance of the outer continental shelf fisheries in the Pacific
Northwest suggests that possible disposal options utilizing sites over the
continental shelf should be critically evaluated for their potential adverse
effects on these fisheries. Such considerations may decrease the likelihood
of selecting such disposal options over other possible choices (e.g.,
open-ocean disposal).
174
-------
Southern California
Rocky shorelines along the southern California coast provide substrate
for both rocky intertidal habitats along the shore and kelp beds just
offshore. Flora and fauna in both habitats are susceptible to adverse
effects of increased turbidity, sediment deposition, and sediment scour
which may occur with nearshore disposal of manganese nodule processing
wastes. Squid spawn just offshore from kelp beds in southern California,
and their demersal eggs may also be vulnerable to burial by these wastes.
In the absence of anthropogenic stresses, it is possible that marine
mammals, once native to the mainland coast and now restricted to the
offshore islands, could return to their former habitat along the rocky
coastlines. California gray whales also transit the area during their
annual migrations between the Bering Sea and Baja California. Whether the
disposal of manganese nodule processing wastes would have adverse effects on
marine mammals is unknown, however. Nearshore submarine canyons may receive
consideration as potential sites for the disposal of manganese nodule
wastes, since they serve as conduits for the transport of sedimentary
material into deeper waters offshore. As discussed above, however, these
canyons are unique biological habitats with a characteristic benthic fauna.
Possible adverse effects on these organisms should be considered in
selecting a site for the disposal of these wastes. As is the case for the
Pacific Northwest, strong coastal upwelling could serve as a mechanism for
shoreward transport of wastes.
Several features of the California borderland could make this area more
attractive for the disposal of manganese nodule processing wastes than more
typical continental shelf areas in other regions. The presence of deep
basins with a depauperate benthic fauna attributed to depressed oxygen
concentrations suggests that these areas could serve as disposal sites with
minimal impact on benthic organisms. Due to the narrowness of the southern
California shelf, groundfish fisheries are limited. The primary fisheries
in the southern California Bight are for pelagic species, so disposal
methods which introduce the wastes deep in the ocean (e.g., surface dump or
subsurface dispersal) would be expected to have a minimal impact on southern
California fisheries. Demersal species, especially those with demersal eggs
(e.g., California halibut) could still be affected, however. Pelagic
species, especially those whose larvae are dependent on adequate
concentrations of planktonic organisms (e.g., jack mackerel, anchovies)
would tend to be more susceptible to adverse effects of manganese nodule
waste disposal if the wastes were dispersed at the surface. It is important
to note the presence of sensitive offshore hard bottom banks, however.
These areas represent unique habitats which are probably highly sensitive to
solids deposition.
Open-ocean environments beyond the continental slope off southern
California are similar in many respects to open-ocean environments in other
regions. Pelagic fisheries are limited, and manganese nodule waste disposal
would not be expected to have adverse effects on the wide-ranging target
species (e.g., tuna, albacore). The biomass of benthic fauna on the
deep-sea floor is sparse since the terrigenous sediments and their
associated organic fraction are currently being deposited in the deep basins
175
-------
of the continental borderland, and are not being transported to the deep sea
by turbidity currents as in other regions. Open-ocean disposal of manganese
nodule processing wastes in this region would therefore be expected to have
relatively minor ecological effects.
EVALUATION OF DISPOSAL OPTIONS
The relative effects of general disposal areas (nearshore, shelf, and
deep ocean) on the significance of environmental considerations is evaluated
in Table 34. Based on relative deposition rate, dilution, and potential
effects on fisheries, the nearshore disposal options have a relatively high
potential for impact. This potential is counteracted, however, by the
limited area affected and the generally lower sensitivities and higher
recovery potential of nearshore organisms. In the deep ocean, high
dilutions and low deposition rates can be maintained; however, the organisms
are probably more sensitive to a given concentration or depositional rate.
Within a general disposal area, there are several environmental
considerations relative to the specific disposal options. In nearshore
areas, the submarine outfall would generally have a higher potential for
impact than surface dumping. Because of construction constraints and
associated costs, outfalls generally discharge very near the shoreline.
Hence, the potential exists for shoreward transport of the wastes. For
reject material, the potential for initial dilution of the waste would be
considerably less for an outfall relative to surface dumping. Moreover, the
outfall must be located in .an area where bottom slope would result in an
initial offshore transport of discharged material. Submarine canyons, such
as those occurring in southern California and Hawaii, may offer an efficient
mechanism for offshore transport of waste discharged near the canyon head
through an outfall. However, such environments may contain a unique fauna
compared to other coastal areas, resulting in significant environmental
considerations for canyon discharges.
The environmental advantages of an outfall are associated with the
confinement of the waste to bottom waters. Thus, potential impacts on
plankton and pelagic fishes are minimized.
Surface dumping in nearshore areas could be conducted farther from
shore than potential outfall lengths, resulting in a lower potential for
effects on shoreline marine communities. Higher dilution could also be
achieved prior to reject deposition. Whereas an outfall discharge would
continually contact the same bottom area, dumping could be spread over a
large area if such a procedure was determined to be environmentally
advantageous. Dumping in nearshore areas would result in contact of the
waste plume with water column organisms. If very small particles were
present in the waste, surface or subsurface plumes could exist for extended
periods.
Three basic disposal options are available for offshore areas over the
continental shelf or in the deep ocean: dumping, surface dispersal, or
subsurface dispersal. Each of these disposal options has advantages and
disadvantages which are dependent upon specific environmental concerns. The
176
-------
TABLE 34. EFFECTS OF DISPOSAL AREA ON FACTORS RELATED TO POTENTIAL
IMPACTS OF HASTE DISPOSAL
Disposal
Area
Nearshore
Shelf
Deep ocean
Relative
Deposition
Rate
High
Moderate
Low
Relative
Area
Affected
Limited
Moderate
Extensive
Potential
Dilution
Limited
Moderate
High
Relative
Organism
Sensitivities
Low
Moderate
High
Recovery
Potential
High
Moderate
Low
Trophic
Link with
Fisheries
High
Moderate
to high
Very
1 i mi ted
-------
use of surface dumping or subsurface dispersal would minimize potential
effects on epipelagic plankton and fishes. The transit time of a waste
plume in the surface layer is limited with a surface dump. Thus, the
contact time with the waste and the spatial extent of the plume are
minimized. Of the three options, dumping would result in the highest
particle deposition rate per unit bottom area. Thus, potential effects on
benthic organisms occurring within the depositional area are highest for
that technique. Dumping offers the environmental advantage of confining
potential effects to a smaller area than would be potentially affected by
dispersal. Moreover, subsequent monitoring would be simplified by reducing
the depositional area.
Surface dispersal techniques could be used to provide a high initial
dilution of wastes in addition to a lower depositional rate per unit area.
Thus, concentrations of reject material would be less in the water and on
the bottom. However, the total areal extent of potential effects would be
greater.
The environmental considerations for each disposal alternative are also
dependent upon the specific biological and oceanographic characteristics of
the disposal site. The general disposal options for each representative
disposal area are evaluated in Table 35. The ranking follows the previously
described generic pattern whereby disposal in nearshore areas has a greater
environmental significance than disposal in deeper, offshore waters. The
greater significance in nearshore areas results from the following factors:
• High productivity
• Limited dilution and dispersal
• Commercial and recreational fisheries
• Sensitive or unique habitats
• Higher ratio of potentially affected habitat to total
available habitat.
It should be emphasized, however, that, although the deep ocean waters have
been given a lower relative significance in this ranking procedure, there
are several factors which could modify this relationship. The greater
sensitivity of deep-ocean organisms to anthropogenic stress, from a
documented and theoretical perspective, could alter these relationships when
site-specific data are examined in detail and organisms' tolerances to
actual reject material are studied. The great difficulty and expense of
monitoring deep ocean communities results in high uncertainty of detecting
and documenting effects if they occur. Moreover, the high dispersion
potential of the open ocean results in considerable uncertainty associated
with the ultimate fate of reject material.
For the nearshore disposal options, there are some differences in the
ranking of environmental considerations relative to representative disposal
sites. The differences are mainly associated with the regional fisheries,
178
-------
TABLE 35. EVALUATION OF THE ENVIRONMENTAL SIGNIFICANCE OF
DISPOSAL AREA OPTIONS WITHIN EACH REPRESENTATIVE DISPOSAL AREA
Nearshore
Pacific
Northwest
Southern
Cal i form' a
Outfall
4
3
Dump
3
3
Shelf
Dump
2
2
Deep Ocean
Dump
1
1
Hawaii 2 2 N/A
Western Gulf
of Mexico N/A 3
Note: Each disposal option is ranked from 1 to 4, with a rank of 4
representing the greatest environmental significance.
179
-------
importance of demersal organisms (i.e., those species most susceptible to
impact), the potential for offshore transport of discharged or dumped
material, and the water depth available nearshore. Based on such
considerations, the nearshore waters of Hawaii, specifically the windward
coast, would have a lower relative significance than southern California or
the Pacific Northwest.
Selection of the most appropriate disposal technique from an
environmental perspective would require information on the potential
toxicity of the waste to marine organisms and development of reliable
methods to predict the dispersion and fate of waste material. With such
information, the advantages and disadvantages of each disposal technique
could be evaluated for the following attributes:
• Area affected
• Severity of effects
• Duration of effects
• Populations at risk.
180
-------
8. RESEARCH AND STUDY REQUIREMENTS FOR ASSESSING
REJECT OCEAN DISPOSAL
Research and study requirements for assessing the impact of ocean
disposal of manganese nodule processing waste are based upon the
requirements of the ocean dumping or discharge regulations (Chapter 2) and
upon the significant environmental concerns developed in the previous
chapter.
Manganese nodule processing waste may be acceptable for ocean disposal
based upon the information developed in this report. However, because
representative pilot-scale processing plants are currently not in operation,
it is presently not possible to adequately assess the toxicity and
bioaccumulation potential of the waste.
The physical fate of dumped or discharged processing wastes must be
predicted to enable calculation of initial dilution and estimation of
subsequent transport and deposition. While techniques are readily available
to accomplish portions of the various predictive tasks required,
standardized methodologies should be developed.
The recommendation-s presented in this chapter describe further research
which may be needed to assess the acceptability of manganese nodule
processing waste for ocean disposal. Wastes from representstive pilot-scale
(or prototype plants, if possible) operations of each processing plant
proposed should be evaluated in accordance with the recommendations below.
Although comments are provided on the need for baseline studies of proposed
disposal sites, this report is not intended to provide detailed
recommendations on disposal site selection studies. Such recommendations
should be site specific and are beyond the scope of this report.
BASIS FOR RECOMMENDATIONS
Regulatory Requirements
Research on the effects of ocean disposed wastes has not been of high
priority in recent years because the original objectives of the Marine
Protection, Research, and Sanctuaries Act and the London Dumping Convention
were to terminate consideration of the oceans as a waste disposal option.
For instance, the National Ocean Pollution Research and Development and
Monitoring Planning Act of 1978 (PL 95-273) assigns a low priority to
studying the effects of dumping of sewage sludge, because the MPRSA
"requires that all ocean dumping of sewage sludge be phased out by
1981." However, through recent activities including a court decision which
ruled that the MPRSA did not authorize EPA to ban the dumping of sludge
without considering the alternatives to ocean dumping, NACOA's
recommendations for ocean disposal, and industrial and public concern,
181
-------
suggests that ocean disposal policies in the future may allow for various
types of wastes to be permitted for ocean disposal.
Based upon the review of existing ocean disposal regulatory policies,
it appears that future research programs need to be established to fill some
of the existing data gaps in describing the composition and fate and effects
of manganese nodule processing wastes. From a regulatory viewpoint,
research activities should be directed in the following areas:
• Chemical characterization - Complete characterization of the
processing wastes to trace levels is needed. Studies may
need to investigate waste components availability in the
ionic form. State of the art procedures for these
determinations also need to be developed.
• Physical characterization - Research in this area is needed
to define appropriate methodologies to determine the various
parameters necessary to predict the fate and initial
dilution of the material to be disposed of.
• Biological characterization - Based upon the proposed
modifications to the ocean dumping regulations, standard
procedures need to be developed to determine bioaccumulation
potential and chronic effects on "appropriate sensitive
marine organisms" and "appropriate sensitive benthic marine
organisms." These tests need to be designed for
phytoplankton and zooplankton species, crustacean or
molluscan species, fishes, and benthic organisms including
filter feeders, deposit feeders and burrowing species.
These organisms must be representative of those living in or
near the proposed disposal site. The biology of the
deepwater species is not well documented and greater
research is essential.
While these are the primary research areas, the following areas also
need to be investigated:
• Technologies appropriate for the reuse or recycling of
manganese nodule processing wastes
• Further treatment methodologies to reduce the concentration
of potentially harmful constituents
• Cost effective, innovative monitoring methodologies (i.e.,
acoustics, remote sensing, etc.).
Major Environmental Concerns
As described in detail in the preceding chapter, the potential
environmental impacts of the marine disposal of manganese nodule processing
wastes are quite diverse, and they can be expected to vary considerably with
the receiving environment and with the disposal method. With regard to
182
-------
subjects which can be recommended for further study in order to assess the
feasibility of the marine disposal of these wastes, certain potential
impacts must be considered to be of greater concern than others. In
particular, impacts associated with organisms inhabiting the water column
must be deemed of lesser concern, simply because the wastes will settle out
of the water column and the exposure of these organisms to the wastes will
consequently be limited. On the contrary, potential impacts of the disposal
of these wastes on benthic organisms are of greater concern, simply because
the wastes are expected to accumulate on the sea floor, and therefore
benthic organisms may be buried or smothered by the wastes or they will have
to continue to exist in the presence of these wastes for extended periods.
The location of the disposal site will have a large influence on
whether or not appropriate scientific studies can be designed to assess the
potential for environmental impact of the marine disposal of these wastes.
Effects of the open-ocean disposal of these wastes on the deep-sea benthos
will be particularly difficult to analyze. Very little is known about the
life histories, physiology, biochemistry, and physical/chemical tolerances
of deep-sea benthic organisms. The technological problems of bringing back
live, representative samples of these organisms, without subjecting them to
radical changes in temperature and pressure, preclude performing meaningful
experiments with them. In addition, there would be severe problems with
even detecting the responses of deep benthic communities to waste disposal,
should they occur. Jumars (1981) has discussed the similar problems
involved in detecting impacts on benthos of manganese nodule mining. For
predictions of potential effects of waste disposal on deep-sea benthic
organisms, it may have to suffice to estimate the depth of deposition of
these wastes on the deep-sea floor and to judge whether such a deposit is
likely to have any effect on the benthos. While such predictions of
biological effects are somewhat arbitrary, they may be the only option for
assessing potential impacts on the deep-sea benthos. It should be
recognized, however, that future technological advances in deep ocean
sampling methods may enable reliable assessment of impacts on these
communities.
On the continental shelves and nearshore, it may be possible to collect
representative benthic organisms, perform experiments and bioassays on them,
and thereby estimate the potential for adverse impacts of waste disposal on
these organisms. Beyond the physical effects of simply smothering and
killing the benthic organisms, two potentially significant impacts of the
wastes are related to their chemical characteristics. These are direct
toxic effects due either to the metals or other chemical constituents within
the wastes, and bioaccumulation of either metals or other potentially-toxic
substances contained within the wastes. The latter is especially important
when the subject organisms are in food chains leading to humans, as are many
of the shelf and nearshore species. Routine laboratory analyses (to be
outlined below) exist for the quantification of both toxic effects and
bioaccumulation.
While there is certainly cause for concern regarding potential impacts
of manganese nodule waste disposal on pelagic organisms, it is more
difficult to simulate such effects in the laboratory. Larger organisms
183
-------
(e.g., pelagic fishes, marine mammals) are likely able to avoid areas
subject to high turbidity during disposal operations, and hence are not
liable to be adversely impacted by the marine disposal of these wastes.
Smaller organisms (e.g., phytoplankton, zooplankton) are of course not able
to evacuate areas of high turbidity, and hence may be potentially affected
by manganese nodule waste disposal. In the open ocean, the small temporal
and spatial scale of their exposure to the wastes will tend to minimize the
ecological implications of such impacts, if they occur. In neritic
environments, however, the potential for resuspension of the particulate
wastes is much greater, and therefore these small organisms are potentially
subject to more temporally and spatially extensive impacts of these wastes.
It will, therefore, be worthwhile to include phytoplankton and/or
zooplankton in any laboratory studies designed to assess the potential
impacts of marine manganese nodule processing waste disposal.
Laboratory procedures which can be utilized to examine either toxic
effects of the wastes or the biological availability of trace metals or
other potentially-toxic substances in the wastes will be described below.
Also included below are recommendations for the establishment of baseline
environmental conditions in any area being considered for the disposal of
manganese nodule processing wastes.
BIOLOGICAL ASSESSMENT
Assessment of the Potential for Toxicity
In order to predict toxic impacts of the marine disposal of manganese
nodule processing wastes, it may be necessary to conduct laboratory
bioassays using representative organisms from each of the potential disposal
sites. Bioassay requirements under current regulations are described in
Chapter 2. These bioassays should be conducted using wastes from a
pilot-plant process, with the understanding that they may not be exactly the
same as the wastes from a commercial-seal e plant. Bioassays are currently
required for the liquid, suspended particulate, or solid phases of the
wastes (as defined in a manner analogous to that used for dredged material
bioassays; cf. Environmental Protection Agency/Corps of Engineers, Technical
Committee on Criteria for Dredged and Fill Material 1977).
The liquid phase of the wastes may be evaluated in either of two ways.
Where there is concern about specific substances that may be released in
soluble form, the liquid phase may be analyzed chemically and the results
evaluated by comparison to water quality criteria for those substances,
after allowance for initial mixing. If certain potentially toxic
constituents of the wastes are not included in the water quality criteria,
or if there is reason to be concerned about possible synergistic effects of
certain constituents, liquid phase bioassays may aid in evaluating the
importance and the total net impact of the dissolved chemical constituents
of the wastes. Although comparison of waste constituent concentrations with
water quality criteria may be required from a regulatory standpoint, this
will provide little information of predictive value in assessing potential
adverse effects.
184
-------
The liquid phase bioassays should be conducted with appropriate
sensitive marine organisms from each of the proposed disposal areas,
whenever possible. Adverse impacts of dissolved constituents of the wastes
would likely only occur near the surface since dilution of the liquid
fraction of the wastes would be great at depths below the surface layer
(>100 m). Hence, it is probably only necessary to conduct liquid phase
bioassays with benthic organisms from any nearshore areas considered for
disposal. Bioassays may also be performed on appropriate water column
organisms such as sensitive phytoplankton or zooplankton species.
Considering the varying sensitivity of open-ocean neritic phytoplankton
species discussed in the preceding chapter, it is important to emphasize
that separate bioassays should be conducted using organisms collected in
each of the proposed disposal areas. Guidelines for conducting liquid phase
bioassays are found in EPA/COE (1977). Using these techniques, the effects
of the liquid phase on phytoplankton will be evidenced as an inhibition of
growth, the measured effect on zooplankton will be the death of the test
organisms. It is important to note that it is difficult to predict the
ecological consequences of the death of a certain fraction of the local
population of a particular species. The environmentally protective approach
is to regard any statistically significant increase in mortality compared to
the controls as potentially undesirable. It is also important, however, to
evaluate sublethal effects such as changes in behavior, reproduction, or
growth.
The suspended phase bioassays will provide information on potential
toxic effects due to either the physical presence of the particulates or to
chemical effects of any biologically-active constituents of the
particulates. These bioassays should also be conducted with appropriate
sensitive marine organisms from each of the proposed disposal areas,
whenever possible. It is difficult to conduct and interpret the results of
suspended phase bioassays using phytoplankton (EPA/COE 1977), so it is
herein recommended that a sensitive zooplankton species from each
environment be chosen for analysis. Precedents for examining the effects of
suspended particulate wastes on zooplankton can be found in the work of
Hirota (1981) on potential effects of manganese nodule mining on
macrozooplankton, and in the work of Paffenhofer (1972), who examined
effects of "red mud" on copepods. While adult pelagic fishes are likely to
avoid areas of increased turbidity (Barry 1978), consideration may be given
to assessing the effects of the suspended particulates on larval fishes,
which are much more susceptible to impact (cf. Rosenthal 1971). In
addition, it would seem appropriate to utilize benthic suspension feeders
for these bioassays, since their feeding is potentially threatened by
elevated concentrations of inorganic particulate matter. Standard
procedures for conducting suspended phase bioassays can be found in (EPA/COE
1977).
Solid phase bioassays are perhaps the most important since there is a
greater potential impact on benthic organisms than on pelagic organisms,
simply because these organisms live and feed in and on the deposited solid
phase for extended periods. The major evaluative efforts should therefore
be placed on the solid phase. Bioassays using the solid phase are
especially important because they provide an indication of the speciation
185
-------
(by determining bioavai1ability) of the chemical substances found in the
wastes.
The solid phase bioassays should also be conducted with appropriate
sensitive benthic organisms from each of the proposed disposal areas,
whenever possible. It is herein suggested that species be selected to
include one filter-feeder, one deposit feeder, one burrowing form, and one
demersal fish from the outer continental shelf and from the nearshore
region. Representative types might include a crustacean, an infaunal
bivalve, and an infaunal polychaete (EPA/COE 1977). Standard procedures for
conducting solid phase bioassays can be found in (EPA/COE 1977). A bioassay
technique for testing acute (10-day) toxicity of settleable components of
ocean wastes is described by Swartz et al. (1979). Using this technique for
several infaunal species, infaunal amphipods were identified as a sensitive
species appropriate for most analyses.
These bioassays measure the mortality of the organisms as a function of
exposure to the wastes, although finding a statistically-significant impact
in the laboratory does not necessarily imply that an ecologically important
impact would occur in the field. Once again, the environmentally protective
approach is to regard any statistically significant increase in mortality
compared to the controls as potentially undesirable.
Current regulations require the assessment of significant mortalities
or significant adverse sublethal effects, including bioaccumulation. In
order to adequately assess overall potential toxic impacts of reject
material, it may be necessary in the future to conduct more extensive
chronic and/or sublethal bioassays prior to ocean disposal of reject
material. Such studies, with specific objectives associated with chronic
exposures, may also be required as a result of future changes in the
applicable ocean disposal regulations.
Chronic studies of reject exposures are probably most appropriate for
infaunal or epifaunal invertebrates or for demersal fishes since these
organism groups could be expected to have sustained contact with settled
reject material in a disposal area.
One of the primary concerns with regard to chronic effects is related
to the appropriateness of settled reject material as a substrate for benthic
invertebrates. Deposition of substantial layers of reject material over the
normal substrate could conceivably have significant effects on normal
benthic community structure and function. Infaunal invertebrates are
particularly susceptible to substrate modifications, and most species have
well-defined habitat requirements associated with sediment grain size and
organic material content. Thus, longer term, life cycle bioassays may be
appropriate to evaluate the suitability of deposited reject material as
habitat for infaunal species, with emphasis on food availability and larval
settlement characteristics.
It may also be appropriate to evaluate sublethal effects of
bioaccumulation such as reproductive impairment or reduced growth or
production. Such studies would require the exposure of test organisms for
one or more generations in a chronic exposure regime.
186
-------
Prolonged contact with contaminated sediments has been shown to cause
abnormalities in demersal fishes, primarily associated with liver/gill
disease and fin erosion. Such effects would not be detected during
short-term (e.g., 96 or 240 hour) exposures. Consequently, longer term
exposures (e.g., 5 to 10 weeks) may be necessary to evaluate potential
impacts of solid phase (i.e., deposited) reject material on demersal fishes.
Most of the available procedures for assessing the toxicity of wastes
to be disposed into the marine environment involve acute, lethal bioassays
using exposure times of 96 or 240 h. Although these tests may be valuable
for determining the relative toxicity of a waste, they provide little basis
for predicting the biological effects of waste disposal in the ocean. Two
of the primary limitations are the use of short exposure times and the use
of organism death as the response variable. Short exposure times may be
appropriate for situations where the predicted in situ exposures are from
hours to days (e.g., exposure to plankton). However, organisms which could
potentially be exposed to deposited reject material for extended periods
would require longer term (e.g., life cycle) tests for assessment of
possible effects. As part of the Ocean Disposal Permit Program, life cycle
toxicity tests have been described by the U.S. Environmental Protection
Agency (1978) for three species: a mysid, Mysidopsis bahia; the grass
shrimp, Pa 1aemonetes pugi o; and the sheepshead minnow, Cyprinodon
variegatus. Long-term toxicity and reproductive tests for infaunal
polychaete worms are described by Reish (1980).
Although mortality is usually used as an end point in toxicity studies
because it is easily observable and quantifiable, natural marine populations
may respond considerably to pollutant stress without experiencing lethal
effects. Sublethal responses such as changes in behavior, reproductive
rate, or physiological rates (e.g., respiration) may cause long-term changes
in population levels at pollutant concentrations below lethal levels. Such
responses should be evaluated as part of a toxicity assessment of reject
material.
One of the most serious limitations of laboratory toxicity studies is
the difficulties associated with using measured laboratory responses (lethal
or sublethal) in predicting population or community-level responses. In
most procedures, statistically or graphically determined response estimates
(e.g., 96-h LC5Q) are usually multiplied by an application factor for the
determination of a "safe concentration." Factors used in these calculations
may be highly arbitrary and could be expected to display considerable
variation according to species and type of waste. Moreover, such results do
not provide an indication of the areal effects of a given mortality rate (or
other response) in the marine environment.
One of the major concerns related to ocean disposal of reject material
is the effect of settleable components on benthic communities.
Community-level responses are especially difficult to predict based on
single-species bioassays. One experimental design for assessing pollutant
effects on plankton-derived benthic communities is described by Hansen
(1974) and Sheridan and Badger (1981). This approach may be valuable in the
187
-------
study of reject effects because it could enable a long-term assessment of
both the acute community response and subsequent recolonization of sediments
enriched with reject material.
An additional assessment technique valuable in predicting overall
community responses is the use of large enclosed ecosystems in field
exposures. Such enclosures can be sustained over relatively long periods
and contain naturally occurring organisms at several trophic levels. They
also provide the additional advantage of enabling the study of the natural
flux rates of pollutants among organisms, water, and sediment. The use of
large enclosed ecosystems in marine pollution research is evaluated by
Davies and Gamble (1979).
Assessment of the Bioaccumulation of any Potentially-Toxic Components
One of the primary environmental concerns with regard to the marine
disposal of manganese nodule processing wastes is the bioaccumulation of
trace metals or other potentially toxic substances in the wastes. In
certain situations, bioaccumulation may occur within a food web to such an
extent that it may be harmful to the ultimate consumer, which, especially in
the case of neritic environments, is often man. This may occur without
apparent harm to the intermediate organisms within that food web.
Bioaccumulation can only be expected to occur where there is a long-term
exposure to the wastes, and hence it may only be expected to be of concern
for benthic organisms which will remain in the presence of the wastes for
sufficiently long periods for bioaccumulation to occur.
In the case of manganese nodule processing wastes, the biological
availability of trace metals or other potentially-toxic substances within
the wastes is unknown, and represents one of the critical information
requirements that will enable adequate assessment of potential adverse
impacts. Thus, it may be necessary to conduct laboratory studies exposing
appropriate sensitive marine organisms to pilot plant waste material.
Experimental data from tests with other metalliferous waste materials
indicate that:
1. The bulk metal content of the waste alone does not provide
an adequate indication of the availability of the metal to
organisms.
2. The chemical form of the metal and the physical/chemical
composition of associated materials can affect the
bioavailability of the metal.
3. Bioavailability of metals is highly dependent upon the
animal species and upon the individual metal.
4. Bioavailability from sediments is much less efficient than
from aqueous solutions.
Because the magnitude of the biological uptake of trace metals and other
potentially toxic substances varies with the species of animal, it is not
188
-------
feasible to conduct laboratory studies which will assess the overall
potential for bioaccumulation within neritic food webs. Nevertheless, the
ultimate intent of such studies is to assess whether or not the metals or
other substances are bioavaiTable, and not to determine the level of uptake
within all individual species. Uptake may either be directly from the
particulate wastes or from solution, if the substance of interest leaches
out of the particulate wastes over time.
Benthic species to be studied may include a filter-feeder, a deposit
feeder, a burrowing form, and a demersal fish from the outer continental
shelf and from the nearshore region. Representative studies of
bioaccumulation for deposit-feeding bivalves include Luoma and Jenne (1977)
and Luoma and Bryan (1978). Standard procedures for conducting laboratory
assessments of bioaccumulation can be found in EPA/COE (1977).
The environmental interpretation of bioaccumulation data is even more
difficult than for bioassays because in most cases it is impossible to
quantify either the ecological consequences of a given tissue concentration
of a substance that is bioaccumulated, or even the consequences of that body
burden to the animal whose tissues contain it (EPA/COE 1977). [In the case
of mercury, there is an FDA action level (1.0 ppm), so there would be cause
for concern if the tissue concentration of mercury in commercial species of
fish or shellish exceeded this level.] The environmentally protective
approach is to regard any statistically significant bioaccumulation relative
to control animals as potentially undesirable. Nevertheless, a
statistically significant difference in the laboratory may not predict an
ecologically important impact in the field, but only provides evidence of
biological availability of that substance and suggests consideration of that
fact in the decision making process of where to dispose of these wastes.
To be valuable from a predictive standpoint, bioaccumulation tests
should be conducted in conjunction with detailed analyses of the
physical/chemical exposure conditions. Special emphasis should be placed
upon solubility of metals and sediment/water partitioning.
It may also be of value to assess the potential for food web transfer
of metals contained in reject material. This could be accomplished, for
example, by exposing phytopl ankton cultures to reject suspensions followed
by introduction of herbivorous zoopl ankton. Following the exposure period
zooplankton could be analyzed for bioaccumulation of metals.
Establishment of Baseline Environmental Conditions
If a site is selected for the disposal of manganese nodule processing
wastes, it will be important to establish baseline environmental conditions
for that area, prior to commencing disposal of those wastes. Accurate
baseline descriptions will be necessary in order to compare and contrast
them with conditions at the site at some future date after wastes have been
disposed there. If adequate environmental information for the site already
exists, it may suffice to describe the baseline conditions from a thorough
literature review. In many cases, however, information may be inadequate or
incomplete, and therefore field surveys may be required to better describe
the biological characteristics of the receiving environment.
189
-------
Attention should focus on the benthos and on fishes of commercial or
recreational importance. For reasons described above, it is probably not
reasonable to expect a detailed field survey of the benthic communities in
the deep sea, since it would be difficult to detect an impact there of the
waste disposal, should one occur (Jumars 1981). Technological advances may,
however, enable future assessment of the deep sea benthos. Field surveys of
benthic habitats are currently appropriate, however, for the outer
continental shelf and nearshore habitats. Consideration should be given to
definition of any areas of special biological significance (e.g.,
spawning/nursery areas, migration routes, coral reefs, kelp forests, etc.),
since it may be necessary to avoid waste disposal in such areas.
Monitoring programs should be designed to assess the potential impacts
of reject disposal on susceptible marine communities, with emphasis on
sensitive organisms, habitats of limited distribution, and commercially or
recreational ly important species. Other biotic groups which should be
considered for inclusion in a monitoring program include: phytoplankton,
zooplankton, demersal and pelagic fishes, and infaunal/epifauna! benthos.
It is important that biological studies be conducted in conjunction
with physical/chemical studies to enable quantification of cause/effect
relationships. Moreover, it is important that the fate of reject material
be evaluated as part of the monitoring program to ensure that areas sampled
for biological assessments are actually exposed to the reject material.
Monitoring suTveys conducted during or after the period of disposal of
m.anganese nodule wastes will permit evaluation of whether or not this
practice has adversely impacted the environment at the disposal site.
Optimal survey design will also include pre-disposal surveys of the
designated disposal site and control areas.
CHEMICAL ASSESSMENT
Bioassay techniques are the most direct methods available for assessing
the environmental impact of the ocean disposal of manganese nodule
processing wastes. Chemical analysis of the waste is needed to determine
the concentrations of waste constituents to which the bioassay organisms are
exposed. Without adequate chemical analysis, bioassay results are of little
value and subsequent monitoring of the waste composition cannot be
interpreted.
The primary waste constituents of concern for regulatory purposes are
those known to be in the waste and for which the EPA water quality criteria
currently exist. These compounds include:
Arsenic Mercury
Cadmium Nickel
Trivalent chromium Selenium
Hexavalent chromium Silver
Copper Thallium
Lead Zinc
190
-------
It is recommended that further analysis be performed to determine if any
organic compounds classified by EPA as "priority pollutants" are present in
the waste. This more complete analysis of the waste is also needed to
evaluate which constituents may be responsible for any adverse responses
noted in bioassay tests, and to determine which compounds should be analyzed
in the bioaccumulation tests.
Other elements and compounds not currently listed as priority pollutants
should also be evaluated because of their potential toxicity, their
potential to control chemical speciation, or their nutrient properties.
These constituents are listed below:
Potentially toxic constituents
barium, vanadium, beryllium, and molybdenum
Constituents which control chemical speciation (e.g., of dissolved
forms of potentially toxic constituents)
iron and manganese
Nutrient compounds
nitrogen (ammonia, nitrite, nitrate) and silicon.
Future chemical analyses to characterize manganese nodule processing
wastes and rejects must carefully evaluate the partitioning of the
constituents between the dissolved and parti cul ate phases. Concentrations
of potentially toxic constituents in the dissolved state are expected to be
very low. This is also true of ambient trace constituents dissolved in
seawater. These low concentrations are generally below the detection limits
of standard analytical techniques (cf. Bruland 1980) so that
state-of-the-art analytical techniques will be required. Sample extraction
procedures such as those developed by Bruland et al. (1979) will probably be
necessary.
PHYSICAL ASSESSMENT
The research objectives concerning the fate of materials result in part
from ocean dumping regulations and in part from the inadequacies of the
present computer models. The recommendations are restricted to objectives
which can be accomplished using existing experimental knowledge and physical
theories. Others, which involve fundamental advances in the understanding
of the relevant physical phenomena, are briefly mentioned but are beyond the
scope of this report.
The present regulations concentrate on "initial mixing", which is
defined as the diffusion of material that occurs within 4 hours after
discharge. The model of Brandsma and Divoky (1976), its modification by
Bowers and Goldenblatt (1978), and the model by Brandsma et al. (1980), as
well as others, are all of potential use for the determination of initial
191
-------
mixing. The instantaneous dump models suffer several inadequacies. The
first is in the formulation of fluid entrainment into the cloud. Neither of
the treatments contained in Brandsma and Divoky (1976) and Bowers and
Goldenblatt (1978) are completely consistent with experimental results
(cf. Krisnappan 1975; Bowers and Goldenblatt 1978). If, as is apparent from
these results, the entrainment eventually stops (or decreases radically).
then the determinations of initial dilution and equilibrium level may be
tremendously in error. Errors in entrainment estimation could lead to
serious underestimations of pollutant concentrations and the trapping depth.
Another difficulty occurs in the determination of the fall
velocity-probability distribution of the dumped solids. Morgan (1981) found
that coagulation of fine particles was concentration dependent. Hunt (1980)
also found coagulation to be an important factor controlling sedimentation
rates. Inclusion of the effects of coagulation into a dumping model showed
that a significant alteration of the particle size distribution occurred in
the initial stages of the dump, and that omission of this alteration was
likely to produce a significantly low estimate of particle settling rates.
Continuous discharge models are initially very dependent on the
conditions describing entry of a sediment-laden jet into the water and the
ambient ocean currents (such as the wake in the lee of an offshore
platform). Brandsma et al. (1980) consider some of these in detail. A more
fundamental problem is the effect on fluid entrainment of particles in the
jet. Ditmars and McCarthy (1975) indicate that entrainment is retarded by
the presence of such particles. Hence, initial dilution and trapping levels
may be overestimated.
In both the instantaneous and continuous discharge models mentioned
above, advection and passive diffusion are computed numerically in some
fashion. The behavior of bottom surges is rough. However, the ability to
quantitatively predict the dynamics of such surges is not readily available
in the literature.
The three numerical models discussed above are all complex and, with
proper "adjustments", able to make predictions in complex environments.
However, the monetary costs of producing results for a single set of
conditions for a short time is relatively high and the results are presented
in forms not readily useful for compliance with the proposed regulations. A
useful product, not currently available, would be a semi-analytical -
semi-numerical model which would predict initial dilution and pollutant
concentration contours as a function of time and space. The oceanographic
conditions could be simplified; for example, the current speed, u, could be
assumed to be a function of depth only, or perhaps a function of depth and
time [expressed by a mathematical equation, for instance u(t,z) = a(z)
cos(t)]. The model would execute at a low cost (dollars, or fractions of
dollars) and could incorporate advances in the state of the art, such as the
work of Morgan (1981), as they become publicly available. With such a
model, a wide range of conditions could be investigated which would be
useful in understanding strategies for disposal. Predictions made for
direct comparison with field data should probably be made with the more
complex models previously mentioned or their subsequent modification.
192
-------
The long term fate of suspended particles requires other approaches.
Numerical models of the Brandsma-Divoky type are prohibitively expensive to
run for long periods of time and would require extensive computer memory if
used in their present form. Analytic formulations, using idealized currents
for example, offer approaches which would simulate the expected fate of
particles over long periods of time at low (computer) cost. Lavelle and
Oztergut (1980) present predictions for a single layer. Multiple layers are
necessary for many situations, however. Also important are the effects of
zooplankton. As indicated earlier, these animals ingest very fine particles
and excrete fecal pellets of larger diameter. Thus, inclusion of these
effects in a model may remove the very fine particles in the upper layers of
the water column much-more efficiently than physical means. A multiple
layer analytic model can be written which incorporates transport, vertical
(and horizontal) diffusion, and biological transformation of particles with
methods available at the present time. Since the analytic expressions would
most likely be in the form of infinite series, these could be evaluated by
computer methods at relatively low cost.
193
-------
GLOSSARY
acute toxicity - Causing death or severe damage to an organism by poisoning
during a brief exposure period, normally 96 hours or less, although
there is no clear line of demarcation between acute and chronic
toxicity.
amphipod - Laterally compressed crustaceans, most of which are epibenthic or
infaunal.
benthic - Pertaining to the bottom of the ocean and the organisms living
there.
bioaccumulation - The accumulation of a substance in an organism's tissues
resulting from exposure to the substance in the food, surrounding
water, or sediments.
bioavailability - The availability of a substance for incorporation into an
organism's tissue.
biomagnification - Increase in the concentration of a substance as a
function of trophic level.
bioturbation - Mixing of bottom sediments by organisms.
chronic toxicity - Causing death or damage to an organism by poisoning
during prolonged exposure, which, depending on the organism and the
test conditions and purposes, may range from several days to weeks,
months, or years.
contiguous zone - The entire zone established or to be established by the
United States under Article 24 of the Convention of the Territorial
Sea and the Contiguous Zone. This zone extends from the seaward
boundary of the territorial seas (3 miles out) to a distance of 12
miles seaward of the inland boundary of the territorial sea (line of
ordinary low water).
convective descent - For an instantaneous dump cloud, this is the portion of
the fall of the cloud from discharge to the trapping level.
copepod - Small crustaceans most of which are free living and planktonic.
cumacean - Small infaunal crustaceans with distinctive enlarged head and
thorax.
deep ocean - That portion of the ocean lying at depths greater than the
deepest portion of the continental slope of the adjacent land masses.
194
-------
demersal - Pertaining to organisms living in close association with the
ocean bottom.
discharge - (NPDES) when used without qualification means the "discharge of
a pollutant," which means:
(a)(l) Any addition of any "pollutant" or combination of pollutants to
"waters of the United States" from any "point source," or (2) Any
addition of any pollutant or combination of pollutants to the waters
of the "contiguous zone" or the ocean from any point source other than
a vessel or other floating craft which is being used as a means of
transportation.
(b) This definition includes additions of pollutants into waters of
the United States from: surface runoff which is collected or
channelled by man; discharges through pipes, sewers, or other
conveyances owned by a state, municipality, or other person which do
not lead to a treatment works; and discharges through pipes, sewers,
or other conveyances leading into privately owned treatment works.
This term does not include an addition of pollutants by any "indirect
discharger."
disposal - The discharge, deposit, injection, dumping, spilling, leaking, or
placing of any solid waste or hazardous wastes into or on any land or
water so that such solid waste or hazardous waste or any constituent
thereof may enter the environment or be emitted into the air or
discharged into any waters, including ground waters.
dumping - "Dumping" is defined in the regulations as any disposition of
material provided that it does not encompass several exceptions
including: effluents from discharges covered by the Clean Water Act,
Rivers and Harbor Act, or Atomic Energy Act of 1954, routine effluents
from vessels; the construction of artificial islands or intentional
placement of any device, oyster shells, fish wastes, or any other
material for fisheries development.
dynamic collapse - Transformation of the cloud when it reaches the trapping
level until the particles in the cloud behave independently.
electrowinning - Reductions of metal from a solution by means of
electrochemical processes. When sufficient voltage is applied,
metallic ions in solution are reduced and deposited at the cathode.
epifauna - Benthic animals living on the sediment surface or on a
hard-bottom substrate.
equilibrium level - Synonym for trapping level.
euphotic zone - The surface water layer where available light allows
photosynthesis to be greater than or equal to plant respiration.
195
-------
hydrometallurgical - Pertaining to hydrometall urgy, the treatment of ores,
concentrates, and other metal-bearing materials by wet processes,
usually involving the solution of some component, and its subsequent
recovery from the solution.
infauna - Animals living within sediments on the ocean bottom.
inner shelf - That portion of the continental shelf (or insular shelf in the
case of Hawaii) extending from shore approximately one half way to the
shelf break.
level of neutral buoyancy - Synonym for trapping level.
ligand - The anion or molecule which forms a coordination compound with a
metal ion in solution.
lixiviant - A reagent to extract a soluble constituent from a solid mixture
by washing or chemical leaching.
microgram per liter (ug/1 ) - The concentration at which 1 millionth of a
gram (10~°g) is contained in a volume of 1 liter. Also known as part
per billion (ppb).
mid shelf - At a location approximately mid-way between the shore and the
shelf break.
milligram per kilogram (ug/kg) - The concentration at which 1 thousandth of
a gram (1 milligram) is contained in a mass of 1 kilogram. Also known
as part per million (ppm).
milligram per liter (ug/1) - The concentration at which 1 milligram (10~3g)
is contained in a volume of 1 liter. Also known as part per million
(ppm).
nearshore - That portion of the ocean extending from the shoreline out
across the adjacent shelf, including both intertidal and subtidal
benthic habitats and the overlying water column, to a distance of
several kilometers from shore.
neritic - That region of the ocean overlying the continental shelf.
ocean - Any portion of the high seas beyond the contiguous zone.
open ocean - That portion of the ocean at greater distance from shore than
the base of the continental slope of all adjacent land masses.
opportunistic - Short-lived, fast growing, and rapidly reproducing species;
often the first to colonize disturbed habitats and enriched areas.
outer shelf - That portion of the continental shelf (or insular shelf in the
case of Hawaii) extending from the shelf break approximately one half
way to shore.
196
-------
passive diffusion - Transport of particles by oceanic currents only (i.e.,
no internal dynamic forces in the cloud influence the motion of the
particles in the cloud).
pelagic - Pertaining to the open water zone and organisms living there.
polychaete - Segmented worms with fleshy appendages and bristles. One of
the most abundant groups of marine infauna.
pregnant liquor - A value-bearing solution in a hydrometal 1 urgical
operation.
production - Net production refers to the synthesis of organic matter by
plants (primary production) or the growth increment of animals
(secondary production) over some time period. Gross production is
represented by the total energy and nutrients assimilated, i.e., net
production plus metabolic losses.
raffinate - The solvent-lean, residual feed solution, with one or more
constituents having been removed by extraction or ion exchange.
regulation - The ability of an organism to control tissue concentrations of
a substance by the processes of absorption, metabolism, and excretion.
If a substance is not regulated, tissue concentrations will be
directly dependent upon the concentrations in external media (i.e.,
water or sediments).
rejects - That portion of manganese nodule processing wastes which consists
of leached manganese nodule particles.
sessile - Organisms that are stationary or permanently attached to a
substratum; opposite of freely moving or motile.
speciation (chemical) - The actual form in which a molecule or ion is
present in solution. For example, iodine in aqueous solution may
conceivably exist as one or more of the species Io, I", I3", HIO, 10",
lO^", or as an ion pair or complex, or in the form of organic iodo
compounds.
territorial seas - The belt of the seas measured from the line of ordinary
low water along that portion of the coast which is in direct contact
with the open sea and the line marking the seaward limit of inland
waters, and extending seaward a distance of 3 miles.
trapping level - Depth at which the density of the descending plume or cloud
equals the density of the ambient seawater. If the plume or cloud is
always heavier than the ambient seawater, then the plume or cloud
impacts the bottom, in which case the trapping level is set equal to
the water depth.
197
-------
TABLE OF CHEMICAL SYMBOLS USED IN THIS REPORT
Element Symbol
Aluminum
Antimony
Arsenic
Barium
Beryllium
Bismuth
Boron
Cadmium
Calcium
Cesium
Chromium
Cobalt
Copper
Iron
Lanthanum
Lead
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Selenium
Silicon
Strontium
Silver
Thall ium
Titanium
Vanadium
Zinc
Al
Sb
As
Ba
Be
Bi
B
Cd
Ca
Cs
Cr
Co
Cu
Fe
La
Pb
Mg
Mn
Hg
Mo
Ni
Se
Si
Sr
Ag
Tl
Ti
V
Zn
198
-------
REFERENCES
Allen, J.S. 1973. Upwelling and coastal jets in a continuously stratified
ocean. J. Phys. Oceanogr. 3:245-257.
Alton, M.S. 1972. Characteristics of the demersal fish fauna inhabiting
the outer continental shelf and slope off the northern Oregon Coast, pp.
583-634. In: The Columbia River Estuary and Adjacent Ocean Waters,
Bioenvironmental Studies, A.T. Pruter and D.L. Alverson, (eds). Univ. of
Wash. Press, Seattle, WA.
American Petroleum Institute. 1978. Oil and gas well drilling fluid
chemicals. Bulletin 13F, 1st Ed. American Petroleum Institute, Washington,
D.C. 9 pp.
Anderson, A.R., P.W. Anderson, W.M. Dunstan, L.L. Falk, J.E. Kerrigan, C.D.
Rose, and R. Tollefson. 1979. Sources, pp. 8-58. In: Proceedings of a
workshop on assimilative capacity of U.S. Coastal Waters for pollutants,
E.D. Goldberg, (ed). Working Paper No. 1, NOAA, Environmental Research
Laboratories, Boulder, CO.
Anderson, D.M., and F.M.M. Morel. 1978. Copper sensitivity of Gonyaulax
tamarensis. Limnol. Oceanogr. 23:283-295.
Anderson, G.C. 1972. Aspects of marine phytoplankton studies near the
Columbia River, with special reference to a subsurface chlorophyll maximum.
pp. 219-240. In: The Columbia River Estuary and Adjacent Ocean Waters,
Bioenvironmental Studies, A.T. Pruter and D.L. Alverson, (eds). Univ. of
Wash. Press, Seattle, WA.
Anderson, J.J. 1979. Nutrient chemistry in the tropical North Pacific:
DOMES sites A, B, and C. pp. 113-161. In: Marine Sciences, Vol. 9:
Marine Geology and Oceanography of the Pacific Manganese Nodule Province,
J.L. Bischoff and D.Z. Piper, (eds). Plenum Press, NY.
Anderson, R. 1967. Feeding chronology in two deep-sea fishes off
California. M.S. Thesis. Univ. of Southern California, Los Angeles, CA.
22 pp.
Anderson, W.L., and K.E. Smith. 1977. Dynamics of mercury at coal-fired
power plant and adjacent cooling lake. J. Environ. Sci. Tech., 11(1):75.
Anon., 1975. A summary of possible environmental effects of disposing mine
tailings into Strathcona Sound, Baffin Island. Indian and Northern Affairs,
Canada. 76 pp.
Armstrong, R.S. 1980. Environmental assessment of Buccaneer Gas and Oil
Field in the northwestern Gulf of Mexico, 1975-1980. NOAA Technical
Memorandum NMFS-SEFC-50. 31 pp.
Arrhenius, G. 1963. Pelagic sediments. The Sea. 111:655-727.
199
-------
Arthur, O.K. 1976. Food and feeding of larvae of three fishes occurring in
the California Current, Sardinops sagax, Engraulis mordax. and Trachurus
symmetricus. Fish. Bull., U.S. 74:517-530.
Arthur, O.K. 1977. Distribution, size, and abundance of microcopepods in
the California Current system and their possible influence on survival of
marine teleost larvae. Fish. Bull., U.S. 75:601-612.
Atlas, E., G. Martinez, and C.A. Giam. 1981. Chemical characterization of
ocean dumped waste materials. In: Ocean Dumping of Industrial Wastes,
B.H. Ketchum, R.D. Kester, and P.K. Park, (eds).
Atlas, E., J. Brooks, J. Trefry, T. Sauer, C. Schwab, B. Bernard, J.
Schofield, C.S. Giam, and E.R. Meyer. 1980. Environmental aspects of ocean
dumping in the western Gulf of Mexico. J. Water Poll. Cont. Fed.
52(2):329-350.
Ayers, R.C., T.C. Sauer, R.P. Meek, and G. Bowers. 1980. An environmental
study to assess the impact of drilling discharges in the mid-Atlantic. I.
Quantity and fate of discharges. Presented at the symposium: Research on
Environmental Fate and Effects of Drilling Fluids and Cuttings. Lake Buena
Vista, Florida. January 21-24, 1980.
Barnard, W.D. 1978. Prediction and control of dredged material dispersion
around dredging and open-water pipeline disposal operations. Tech. Rep.
DS-78-13. U.S. Army Engineer Waterways Experiment Station, Environmental
Laboratory, Vicksburg, MS. 114 pp.
Barnes, C.A., A.C. Duxbury, and B.A. Morse. 1972. Circulation and selected
properties of the Columbia River effluent at sea. pp. 41-80. In: The
Columbia River Estuary and Adjacent Ocean Waters, Bioenvironmental Studies,
A.T. Pruter and D.L. Alverson, (eds). Univ. of Wash. Press, Seattle, WA.
Barry, M. 1978. Behaviares, and kawakawa, Euthynnus affinis, to turbidity.
Report by Department of Zoology, Univ. of Hawaii, Honolulu, HI, for the Deep
Ocean Mining Environmental Survey (DOMES) program. 31 pp. plus Tables and
Figures.
Bascom, W., A.J. Mearns, and J.Q. Word. 1978. Establishing boundaries
between normal, changed, and degraded areas, pp. 81-94. In: Coastal Water
Research Project, Annual Report for 1978, W. Bascom (ed). SCCWRP, El
Segundo, CA.
Baseden, S. 1976. Environmental study of the disposal of red mud waste.
Mar. Poll. Bull. 7(l):4-7.
Bathern, K. 1970. Heat storage and advection in the North Pacific Ocean
HIG-70-6.
Behringer, D.W., R.L. Molinari, and J.F. Pesta. 1977- The variability of
anticyclonic current patterns in the Gulf of Mexico. J. Geophys Res
82:5469-5476.
200
-------
Beers, J.R., and G.L. Stewart. 1969. The vertical distribution of
microzooplankton and some ecological observations. J. Cons. perm. int.
Explor. Mer. 33:30-44.
Bigelow, H.R., and W.C. Schroeder. 1953. Fishes of the Gulf of Maine.
Fish Bull., U.S. Fish. Wildlife Serv. 53:557 pp.
Blackman, R.A.A., and K.W. Wilson. 1973. Effects of red mud on marine
animals. Mar. Poll. Bull. 4(11):169-171.
Bodvarsson, G., J.W. Berg, and R.S. Mesecar. 1967. Vertical temperature
gradient and eddy diffusivity above the ocean floor in an area west of the
coast of Oregon. J. Geophys. Res. 72(10):2693-2694.
Boone, C.G., M.A. Granat, and M.P. Farrell . 1978. Aquatic disposal field
investigations Columbia River disposal site, Oregon—evaluative summary.
Tech. Rep. D-77-30. U.S. Army Engineer Waterways Experiment Station,
Vicksburg, MS. 100 pp.
Bourke, R.H., and J.G. Pattullo. 1974. Seasonal variation of the water
mass along the Oregon-northern California coast. Limnol Oceanogr.
1:190-198.
Bowers, G.W., and M.K. Goldenblatt. 1978. Calibration of a predictive
model for instantaneously discharged dredged material. Rep.
EPA-600/3-78-089. U.S. EPA, Environmental Reserach Laboratory, Corvallis,
OR. 155 pp.
Boyden, C.R. 1977. Effect of size upon metal content of shellfish. J.
Mar. Biol. Ass., U.K. 57:675-714.
Brandsma, M.G., and D.J. Divoky. 1976. Development of models for
prediction of short-term fate of dredged material discharged in the
estuarine environment. Contract Rep. D-76-5. U.S. Army Engineer Waterways
Experiment Station, Environmental Effects Laboratory, Vicksburg, MS.
Brandsma, M., and F. Wu. 1980. Development of model to predict drilling
mud plume concentrations in offshore operations. Draft Final Report.
Pasadena, CA.
Brandsma, M.G., L.R. Davis, R.C. Ayers, Jr., and T.C. Sauer, Jr. 1980. A
computer model to predict the short term fate of drilling discharges in the
marine environment, pp. 588-610. In: Proc. of the Symposium Research on
Environmental Fate and Effects of Drilling Fluids and Cuttings. Lake Buena
Vista, Florida. January 21-24, 1980.
Bright, D.B. 1974. Benthic invertebrates, pp. 10-1 through 10-291. In:
A Summary of Knowledge of the Southern California Coastal Zone and Offshore
areas, Vol. II, Biological Environment. M.D. Dailey, B. Hill, and N.
Lansing, (eds). U.S. Dept. Interior, Bureau of Land Management.
201
-------
Bright, T.J. 1977. Coral reefs, nepheloid layers, gas seeps, and brine
flows on hard banks in the northwestern Gulf of Mexico, pp. 39-46. In:
Proc. of the Third International Coral Reef Symposium, Miami, Florida, May,
1977, Vol. I.
Bright, T.J., W.C. Jaap, and C.W. Cashman. 1981. Ecology and management of
coral reefs and organic banks, pp. 53-159. In: Proc. of a Symposium on
Environmental Research Needs in the Gulf of Mexico (GOMEX), Key Biscayne,
Florida, 30 September-5 October, 1979, Vol. IIB. U.S. Dept. Commerce,
National Oceanic and Atmospheric Administration, Miami, FL.
Brock, J.H., and R.E. Brock. 1974. The marine fauna of the coast of
northern Kona, Hawaii. An inventory of fishes and invertebrates recorded
during summer, 1972. Sea Grant Advisory Rep. UNIHI-SEAGRANT-AR-74-02.
Univ. of Hawaii, Honolulu, HI. 30 pp.
Broecker, W.S. 1981. Geochemical tracers and ocean circulation.
In: Evolution of physical oceanography. MIT Press, Cambridge, MA. 623 pp.
Broecker, W.S., 0. Cromwell, Y.H. Li. 1967. Radium-226 and radon-222
concentration in Atlantic and Pacific oceans. Science 158:1307-1310.
Broecker, W.S., J. Cromwell, Y.H. Li. 1968. Rates of vertical eddy
diffusion near the ocean floor based on measurements of the distribution of
excess 222Rn. Earth and Planetary Science Letters 5(2):101-105.
Brooks, N.H. 1960. Diffusion of sewage effluent in an ocean current, pp.
246-267. In: Proc. Int. Conf. Waste Disposal Mar. Environ., Pergamon,
Oxford.
Browning, R.J. 1980. Fisheries of the North Pacific. Alaska Northwest
Publishing Co. Anchorage, AK. 423 pp.
Bruland, K.W. 1980. Oceanographic distibutions of cadmium, zinc, nickel,
and copper in the North Pacific. Earth and Planetary Science Letters.
47:176-198.
Bruland K.W., R.P. Franks, G.A. Knauer, and J.H. Martin. 1979. Sampling
and analytical methods for the determination of cooper, cadmium, zinc, and
nickel at nanogram per liter level in sea water. Analytica Chimica Acta.
105:233-245.
Bryan, G.W., 1979. Bioaccumul ation of marine pollutants. Phil. Tran. R.
Soc. London, B. 286:397-633.
Bryan, G.W., and L.G. Hummerstone. 1973. Adaptation of the polychaete
Nereis diversicolor to estuarine sediments containing high concentrations of
zinc and cadmium.J. Mar. Biol. Ass., U.K. 53:839-857.
Bryan, G.W., and H. Vysal . 1978. Heavy metals in the burrowing bivalve
Scrobicularia pi ana from the Tamar estuary in relation to environmental
levels.J. Mar. Biol. Ass., U.K. 58:89-108.
202
-------
Bullis, H.R., Jr., J.S. Carpenter, and C.M. Ruithmayr. 1971. Untapped
west-central Atlantic fisheries, pp. 374-391. In: Our Changing Fisheries,
S. Shapiro (ed). U.S. Government Printing Office, Washington, D.C.
Burling, R.W., J.E. Mclnerney, and W.K. Oldham. 1981. A technical
assessment of the AMAX/Kitsault molybdenum mine tailings discharge to Alice
Arm, British Columbia. Panel report prepared for the Hon. R. Leblanc, M.P.,
Minister of Fisheries and Oceans, Government of Canada. 154 pp.
Byrne, J.V. 1962. Geomorphology of the continental terrace off the central
coast of Oregon. In: The Ore Bin 24(5):65-75.
Byrne, J.V. 1963a. Geomorphology of the Oregon continental terrace south
of Coos Bay. In: The Ore Bin 25(9):149-155.
Byrne, J.V. 1963b. Geomorphology of the continental terrace off the
northern coast of Oregon. In: The Ore Bin 25(12):201-207.
Byrne, J.V., and D.A. Panshin. 1977. Continental shelf sediments off
Oregon. Oregon State Univ. Extension Marine Advisory Program. Sea Grant 8,
August, 1977. 5 pp.
Cannon, G.A., N.P. Larid, and T.V. Ryan. 1975. Flow along the continental
slope off Washington, Autumn 1971. J. Mar. Res. 33(Suppl.):97-107.
Canterford, G.S., and D.R. Canterford. 1980. Toxicity of heavy metals to
the marine diatom Ditylum brightwelli (West) Grunow: Correlation between
toxicity and metal speciation.J. Mar. Biol. Ass. U.K. 60:227-242.
Carey, A.G., Jr. 1965. Preliminary studies on animal-sediment
interrelationships off the central Oregon Coast. Ocean Sci. Ocean Engin.
1:100-110.
Carey, A.G., Jr. 1972. Ecological observations on the benthic
invertebrates from the central Oregon continental shelf, pp. 422-443. In:
The Columbia River Estuary and Adjacent Ocean Waters, Bioenvironmental
Studies, A.T. Pruter and D.L. Alverson, (eds). Univ. of Wash. Press,
Seattle, WA.
Casey, R.E. 1976. Microzooplankton and microzoobenthos project. A report
to the Bureau of Land Management. 115 pp.
Castilla, J.C., and E. Nealler. 1978. Marine environmental impact due to
mining activities of El Salvador Copper Mine, Chile. Mar. Poll. Bull.
9(3):67-70.
Chan, A.T., and G.C. Anderson, 1981. Environmental investigation of the
effects of deep-sea mining on marine phytoplankton and primary productivity
in the tropical eastern North Pacific Ocean. Marine Mining. 3:121-149.
203
-------
Chen, C.W., D.J. Smith, J.D. Jackson, and J.D. Hendrick. 1975. Organic
sediment model for wastewater outfall, pp. 179-207. In: Proc. of the
Symposium on Modeling Techniques, American Society of Civil Engineers, San
Francisco, CA, September 3-5, 1975.
Chittenden, M.E., Jr., and J.D. McEachran. 1976. Composition, ecology, and
dynamics of demersal fish communities on the northwestern Gulf of Mexico
continental shelf, with a similar synopsis for the entire Gulf. Texas A & M
Univ. Sea Grant Publ. No. TAMU-SG-76-208. 104 pp.
Chittenden, M.E., Jr., and D. Moore. 1977. Composition of the ichthyofauna
inhabiting the 110-m bathymetric contour of the Gulf of Mexico, Mississippi
River to the Rio Grande. Northeast Gulf Sci. 1:106-114.
Clarke, T.A. 1973. Some aspects of the ecology of 1 anternf1shes
(Myctophidae) in the Pacific Ocean near Hawaii. Fish. Bull., U.S.
71:401-434.
Clarke, T.A. 1974. Some aspects of the ecology of stomiatoid fishes in the
Pacific Ocean near Hawaii. Fish. Bull., U.S. 72:337-351.
Clarke, T. A., and P.J. Wagner. 1976. Vertical distribution and other
aspects of the ecology of certain mesopelagic fishes taken near Hawaii.
Fish. Bull., U.S. 74:635-645.
Cleasby, J.V., Sir Frederick Gibberd, J.W. Grimes, and K.H.R. Cuthbert.
1975. Environmental aspects of Boulby mine, Cleveland Potash, Ltd.,
Yorkshire, pp. 691-713. In: Minerals and the Environment, M.J. Jones,
(ed). The Institution of Mining and Metallurgy, England.
Clemens, W.A., and G.V. Wilby. 1961. Fishes of the Pacific Coast of
Canada. Bull. No. 68. Fisheries Research Board of Canada, Ottawa, Ontario,
Canada. 443 pp.
Corps of Engineers (COE). 1980. 1979 Report to Congress on administration
of ocean dumping activities. U.S. Army Corps of Engineers, Water Resources
Support Center, Ft. Belvoir, VA. 44 pp.
Cox, J.A., G.L. Lundquist, A. Przyjazny, and C.D. Schmulbach. 1978.
Leaching of boron from coal ash. J. Environ. Sci. Tech. 12(7'):/'22-1'23.
Crippen, R.W., S.L. Hood, and G. Greene. 1980. Metal levels in sediment
and benthos resulting from a drilling fluid discharge into the Beaufort Sea.
Presented at the symposium: Research on Environmental Fate and Effects of
Drilling Fluids and Cuttings. Lake Buena Vista, Florida. January 21-24,
1980.
Cross, F.A., L.H. Hardy, N.Y. Jones, and R.T. Barber. 1973. Relation
between total body weight and concentrations of manganese, iron, copper,
zinc, and mercury in white muscle of bluefish (Pomatomus saltatrix) and a
bathyl-demersal fish (Antimora rostrata). J. Fish. Res. Board Can.
30:1287-1291.
204
-------
Cumbow, R.C., (ed). 1977. Salmon and salmon hatcheries. Washington Dept.
Fish. Olympia, WA. 51 pp.
Curl, H.C., Jr., and L.F. Small. 1965. Variations in photosynthetic
assimilation ratios in natural marine phytopl ankton communities. Limnol.
Oceanogr. 10(Suppl):R67-R73.
Curray, J.R. 1960. Sediments and history of holocene transgression,
continental shelf, northwest of Gulf of Mexico. In: Recent Sediments:
Northwest Gulf of Mexico. American Association of Petroleum Geologists.
Curray, J.R. 1969. The new concepts of continental margin sedimentation.
American Geological Institute short course lecture notes, 7-9 November 1969,
Philadelphia, PA.
Gushing, D.H. 1973. The possible density-dependence of larval mortality
and adult mortality in fishes, pp. 103-111. In: The Early Life History of
Fish, J.H.S. Blaxter, (ed). Springer-Verlag. Berlin.
Gushing, D.H. 1975. Marine ecology and fisheries. Cambridge Univ. Press,
Cambridge. 278 pp.
Dailey, M.D. 1974. Marine mammals, pp. 12-1 through 12-37. In: A
Summary of Knowledge of the Southern California Coastal Zone and Offshore
Areas, Vol. II, Biological Environment. M.D. Dailey, B. Hill, and N.
Lansing, (eds). U.S. Dept. Interior, Bureau of Land Management.
Dames and Moore. 1977a. Description of manganese nodule processing
activities for environmental studies. Volume I: Processing Systems
Summary. U.S. Department of Commerce, NOAA Office of Marine Minerals.
Dames and Moore. 1977b. Description of manganese nodule processing
activities for environmental studies. Vol. Ill: Processing Systems
Technical Analyses. U.S. Department of Commerce, NOAA Office of Marine
Minerals.
Dauer, D.M., and J.L. Simon. 1976. Repopulation of the polychaete fauna of
an intertidal habitat following natural defaunation: species equilibrium.
Oecologia 22:99-117-
Davies, J.M., and J.C. Gamble. 1979. Experiments with large enclosed
ecosystems. Phil. Trans. R. Soc. Lond. B. 286:523-544.
Davis, L.R., G.W. Bowers, and M.K. Goldenblatt. 1980. Workbook/users
manual for prediction of instantaneously dumped dredged materials. Rep.
EPA-600/3-80-034. U.S. EPA, Environmental Research Laboratory, Corvallis,
OR. 217 pp.
Davison, R.L., D.F.S. Natusch, J.R. Wallace, and C.A. Evans, Jr. 1974.
Trace elements in fly ash: Dependence of concentration on particle size. J.
Environ. Sci. Tech. 8(13):1107-1112.
205
-------
Defant, A. 1961. Physical Oceanography. Pergamon Press, London.
Dehlinger, P., R.W. Couch, D.A. McManus, and M. Gemperle. 1970. Northeast
Pacific Structure, pp. 133-189. In: A.E. Maxwell, (ed). The Sea 4(11).
Devaney, D. M., and L.G. Eldredge (eds). 1977. Reef and shore fauna of
Hawaii. Section 1: Protozoa through Ctenophora. Bernice P. Bishop Museum
Special Publication No. 64(1). 278 pp.
Dietrich, Gunter. 1939. Das Amerikanische Mitt1emeer. Ein
meereskundlicher uberblick. Zeitschr. d. Gesellsch. f. Erdkunde zu Berlin,
1939, Nr. 3/4, pp. 108-130.
Ditmars, J.D., and M.J. McCarthy. 1975. Particle-laden jets with
application to ocean dumping, pp. 335-351. In: Symposium on Modeling
Techniques. American Society of Civil Engineers, New York.
Dodimead, A.J., F. Favorite, and T. Hirano. 1963. Salmon of the North
Pacific Ocean, Part II. Review of the Oceanography of the Sub-Arctic
Pacific Region. Int. North Pac. Fish. Comm. Bull. 13. 195 pp.
Doughty, F.T.C. 1975. Copper mining and extraction at Repparfjord. Mining
Magazine (London) 132:31-39.
Down, G.C., and A.J.B. Mill. 1978. Marine disposal of mine and mill
tailings, pp. 421-437. In: Proc. of the Eleventh Commonwealth Mining and
Metallurgical Congress, Hong Kong, 1978. M.J. Jones, (ed). The Institution
of Mining and Metallurgy, England.
Down, G.C., and J. Stocks. 1977. Methods of tailings disposal. Mining
Magazine, pp. 345-359.
Dreesen, D.R., E.S. Gladney, J.W. Owens, B.L. Perkins, C.L. Wienke, and
L.E. Wangen. 1977. Comparison of levels of trace elements extracted from
fly ash and levels found in effluent waters from a coal-fired power plant.
J. Environ. Sci. Tech. 11(10):1017-1019.
Dresher, W.H., and D.W. Rodolff. 1981. Smelter pollution abatement: How
the Japanese do it. Exploration and Mining Journal, pp. 67-74.
Ebeling, A.W., G.M. Cailliet, R.M. Ibara, F.A. DeWitt, Jr., and D.W. Brown.
1971. Pelagic communities and sound scattering off Santa Barbara,
California, pp. 1-19. In: Proc. of an International Symposium on
Biological Sound Scattering in the Ocean, G.B. Farquhar, (ed). Maury Center
for Ocean Science, Washington, D.C.
Eber, L.F. 1977. Contoured depth-time charts (0 to 200 m, 1950 to 1966) of
temperature, salinity, oxygen, and sigma-T at 23 CalCOFI stations in the
California Current. CalCOFI Atlas No. 25, Scripps Institution of
Oceanography, La Jolla. 231 pp.
206
-------
Eisler, R. 1979. Toxic cations and marine biota: analysis of research
effort during the three-year period 1974-1976. pp. 111-149. In: Marine
Pollution: Functional Responses, W.B. Vernberg, A. Calabrese, P.P.
Thurberg, and F.J. Vernberg (eds). Academic Press, NY.
Elderfield, H., and A. Hepworth. 1975. Diagenesis, metals, and pollution
in estuaries. Mar. Poll. Bull. 6(6):85-87.
Elliot, B.A. 1979. Anticyclonic rings and the energetics of the
circulation of the Gulf of Mexico. Ph.D. Dissertation. Texas ASM
University. College Station, Texas.
Ellis, D.V. 1975. Pollution controls on mine discharges to the sea. pp.
677-686. In: International Conference on Heavy Metals in the Environment.
Toronto, Canada, October 27-31, 1975.
Ellis, D.V. 1978. Effectiveness of existing pollution controls as shown by
four case-histories; and recommendations for future control. A submission
to the Public Inquiry into Pollution Control Objectives for the Mining,
Mine-Milling, and Smelting Industries, held by the Province of British
Columbia, January, 1978. 23 pp.
El-Sayed, S.Z., and J.T. Turner. 1974. Productivity of the Antarctic and
tropical/subtropical regions: A comparative study, pp. 463-503. In:
Proceedings of the SCAR/SCOR conference on polar oceanography. M. Dunbar
(ed). Arctic Institute of North America, McGill University, Montreal,
Quebec, Canada.
Emery, K.O. 1960. Basin plains and aprons on southern Calfirdnia. J.
Geol. 68:464-479.
Engel, D.W., and W.G. Sunda. 1979. Toxicity of cupric ion to eggs of the
spot Leiostomus xanthurus and the Atlantic silverside Menidia menidia. Mar.
Biol. (Berl.) 50:121-126.
Engel, D.W., W.G. Sunda, and B.A. Fowler. 1981. Factors affecting trace
metal uptake and toxicity to estuarine organisms. I. Environmental
parameters, pp. 129-144. In: Biological Monitoring of Marine Pollutants,
F.J. Vernberg et al. (eds). Academic Press, New York, NY.
Environmental Protection Agency/Corps of Engineers, Technical Committee on
Criteria for Dredged and Fill Material. 1977. Ecological evaluation of
proposed discharge of dredged material into ocean waters. Environmental
Effects Laboratory, U.S. Army Engineer Waterways Experiment Station,
Vicksburg, MS. 24 pp. plus appendices.
Eppley, R.W., J.N. Rogers, and J.J. McCarthy. 1969. Half-saturation
constants for uptake of nitrate and ammonium by marine phytoplankton.
Limnol. Oceanogr. 14:912-920.
Eppley, R.W., C. Sapienza, and E.H. Renger. 1978. Gradients in
phytopl ankton stocks and nutrients off southern California in 1974-76.
Estuarine Coastal Mar. Sci. 7:291-301.
207
-------
Erickson, S.J., N. Lackie, and I.E. Maloney. 1970. A screening technique
for estimating copper toxicity to estuarine phytoplankton. J. Water Poll.
Cont. Fed. 42:R270-R278.
Eustace, I.J. 1974. Zinc, cadmium, copper, and manganese in species of
finfish and shellfish caught in the Derwent Estuary, Tasmania. Aust. J. Mar.
Freshwat. Res. 25:209-220.
Evans, J.B., D.V. Ellis, and C.A. Pelletier. 1972. The establishment and
implementation of a monitoring program for underwater tailing disposal in
Rupert Inlet, Vancouver Island, British Columbia. In: Tailing Disposal
Today, C.L. Alpin and G.O. Argall , Jr. (eds). Proceedings of the First
International Tailings Symposium, Tucson, Arizona, 1972. Miller Freeman
Publications, Inc., San Francisco.
Evans, J.B., and G.W. Poling. 1975. Discharging flotation mill tailings
into a coastal inlet. Department of Mineral Engineering, Univ. of British
Columbia. Presented at 77th Annual General Meeting of the Canadian
Institute of Mining and Metallurgy. 45 pp.
Ewing, J.I., J.L. Worzel, and M. Ewing. 1962. Sediments and oceanic
structural history of the Gulf of Mexico. J. Geophys. Res. 67(6):2509-2527.
Favorite, F., A.J. Dodimead, and K. Nasu. 1976. Oceanography of the
subarctic Pacific region, 1960-1971. Int. North Pac. Fish. Comm. Bull. No.
33. 187 pp.
Fay, R.C. 1972. An evaluation of the heaTth of the benthic marine biota of
Ventura, Los Angeles, and Orange Counties. Prepared for Southern California
Assoc. of Governments.
Fischer, H.B., E.J. List, R.C.Y. Koh, J. Imberger, and N.H. Brooks. 1979.
Mixing in inland and coastal waters. Academic Press, NY. 483 pp.
Fisher, N.S. 1977. On the differential sensitivity of estuarine and
open-ocean diatoms to exotic chemical stress. Amer. Natur. 111:871-895.
Fornari, D.J., A. Malahoff, and B.C. Heezen. 1979. Submarine slope
microstructure and volcanic substructure of the Island of Hawaii inferred
from visual observations made from U.S. Navy deep submergence vehicle (DSV)
"Sea Cliff." Mar. Geol. 32:1-20.
Frey, H.W. (ed). 1971. California's living marine resources and their
utilization. California Dept. of Fish and Game. 148 pp.
Frost, B.W., and L.E. McCrone. 1979. Vertical distribution, diel vertical
migration, and abundance of some mesopelagic fishes in the eastern subarctic
Pacific Ocean in summer. Fish. Bull., U.S. 76:751-770.
Gaboury, D.R., and K.D. Stolzenbach. 1979. Dispersion zone characteristics
of ocean discharges. Tech. Rep. No. 244. R.M. Parsons Laboratory for Water
Resources and Hydrodynamics, Massachusetts Institute of Technology.
208
-------
Gallaway, B.J., and K. Strawn. 1974. Seasonal abundance and distribution
of marine fishes at a hot-water discharge in Galveston Bay, Texas.
Contributions in Marine Science 18:71-137.
Gargett, A.E. 1976. An investigation of the occurrence of oceanic
turbulence with respect to finestructure. J. Phys. Oceanogr. 6:139-156.
Gilbert, W.E., A. Huyer, E.D. Barton, and R.L. Smith. 1976. Physical
oceanographic observations off the Oregon coast, 1975, WISP and UP-75.
Oregon State University, Data Report 64, Reference 76-4.
Gilmartin, M., and N. Revelante. 1974. The "Island Mass" effect on the
phytoplankton and primary production of the Hawaiian islands. J. exp. mar.
Biol. Ecol. 16:181-204.
Gilmour, A.E. 1969. Precise temperature measurements in the Cayman Trench.
Deep-Sea Res. 16:197-203.
Gladney, E.S., I.E. Wangen, D.B. Curtis, and E.T. Jurvey. 1978.
Observations on boron release from coal-fired power plants. J. Environ.
Sci. Tech. 12(9):1084-1085.
Glude, J.B. 1971. Pacific northwest fisheries, pp. 234-257. In: Our
changing fisheries, S. Shapiro (ed). U.S. Govt. Printing Office,
Washington, D.C.
Gosline, W.A., and V.E. Brock. 1960. Handbook of Hawaiian fishes. Univ.
Hawaii Press, Honolulu, HI. 372 pp.
Goyette, D.E. 1975. Marine tailings disposal-case studies. Paper
presented at: Mining Effluent Regulations/Guidelines and Effluent Treatment
Seminar, Banff, Alberta, Dec. 9-10, 1975. 13 pp.
Goyette, D.E., and H. Nelson. 1977. Marine environmental assessment of
mine waste disposal into Rupert Inlet, British Columbia. Surveillance Rep.
EPS PR-77-11, Environmental Protection Service, West Vancouver, B.C. 93 pp.
Gregg, M.C. 1977. Variations in the intensity of small scale mixing in the
main thermocline. J. Phys. Oceanogr. 7:436-454.
Gregg, M.C., C.S. Cox, and P.W. Hacker. 1973. Vertical microstructure
measurements in the central north Pacific. J. Phys. Oceanogr. 3:458-469.
Grieg, R.A., and D.R. Wenzloff. 1977. Trace metals in finfish from the New
York Bight and Long Island Sound. Mar. Poll. Bull. 8(9):198-200.
Grieg, R.A., D.R. Wenzloff, A. Adams, B. Nelson, and C. Shelpuk. 1977.
Trace metals in organisms from ocean disposal sites of the middle eastern
United States. Arch. Environm. Contam. Toxicol. 6:395-409.
209
-------
Grieg, R.A., D.R. Wenzloff, and J.B. Pearce. 1976. Distribution and
abundance of heavy metals in finfish, invertebrates, and sediments collected
at a deepwater disposal site. Mar. Poll. Bull. 7(10):185-187.
Grigg, R.W. 1965. Ecological studies of black coral in Hawaii. Pac. Sci.
19(2):244-260.
Grigg, R.W. 1974. Distribution and abundance of precious corals in Hawaii.
pp. 235-240. In: Proceedings of the Second International Symposium on
Coral Reefs, Vol. 2. A.M. Cameron, B.M. Campbell, A.B. Cribb, R. Endean,
J.S. Jell, O.A. Jones, P. Mather, and F.H. Talbot (eds).
Griggs, G.B., A.G. Carey, Jr., and L.D. Kulm. 1969. Deep-sea sedimentation
and sediment-fauna interaction in Cascadia Channel and on Cascadia Abyssal
Plain. Deep-Sea Res. 16:157-170.
Gross, M.G. 1965. The carbonate content of surface sediments from the
northeast Pacific Ocean. Northwest Sci. 39(3):85-92.
Gross, M.G. 1977. Oceanography, a view of the earth (2nd edition).
Prentice-Hall, Inc., Englewood Cliffs, NJ. 497 pp.
Gulf of Mexico and South Atlantic Fishery Management Councils. 1981.
Fishery management plan final environmental impact statement, regulatory
impact review, draft regulations for the coastal migratory pelagic resources
(mackerels). Tampa, Florida, and Charleston, South Carolina.
Gulf of Mexico Fishery Management Council (GMFMC). 1980a. Fishery
management plan and proposed regulations for the shrimp fishery of the Gulf
of Mexico, United States waters. GMFMC, Tampa, FL.
Gulf of Mexico Fishery Management Council (GMFMC). 1980b. Environmental
impact statement, fishery management plan and regulatory analysis for the
reef fish resources of the Gulf of Mexico. GMFMC, Tampa, FL.
Gulf of Mexico Fishery Management Council (GMFMC). 1981. Draft fishery
management plan, environmental impact statement and regulatory analysis for
groundfish in the Gulf of Mexico. GMFMC, Tampa, FL. 39 pp.
Gulland, J.A. (ed). 1971. The fish resources of the ocean. Fishing News
(Books) Ltd., West Byfleet, Surrey-, England. 255 pp.
Halcrow, W., D.W. Mackay, and I. Thornton. 1973. The distribution of trace
metals and fauna in the Firth of Clyde in relation to the disposal of sewage
sludge. J. Mar. Biol. Ass. U.K. 53:721-739.
Halpern, D. 1974. Observations of the deepening of the wind-mixed layer in
the northeast Pacific Ocean. J. Phys. Oceanogr. 4:454-466.
Halpern, D. 1976. Measurements of near-surface wind stress over an
upwelling region near the Oregon coast. J. Phys. Oceanogr. 6:108-112.
210
-------
Halpern, D. , J.R. Holbrook, and R.M. Reynolds. 1973. Physical
oceanographic observations made by the Pacific Oceanographic Laboratory off
the Oregon coast during July and August, 1972. Int. Decade Ocean
Exploration, Costal Upwelling Ecosystems Analysis, Tech. Rep. 3. Ref.
M73-46, Univ. of Wash., Dept. of Oceanography, Seattle, WA. 205 pp.
Hansen, D.J. 1974. Aroclor 1254: effect on composition of developing
estuarine animal communities in the laboratory. Cont. in Mar. Sci.
18:19-33.
Harden Jones, F.R. 1968. Fish migrations. Edward Arnold, London. 325 pp.
Harlett, J.C. 1972. Sediment transport on the northern Oregon continental
shelf. Ph.D. Thesis. Oregon State University, Corvallis, OR. 120 pp.
Hart, J.L. 1973. Pacific fishes of Canada. Bull. No. 180. Fisheries
Research Board of Canada, Ottawa, Ontario, Canada. 740 pp.
Hartman, 0. 1963. Submarine canyons of southern California. Part II.
Biology. Allan Hancock Pacific Expeditions 27(2):424 pp.
Hartman, 0., and J.L. Barnard. 1958. The benthic fauna of the deep basins
off southern California , Part 1. Allan Hancock Pacific Expeditions
22(l):l-67.
Hartman, 0., and J.L. Barnard.- 1960. The benthic fauna of the deep basins
off Southern California, Part 2. Allan Hancock Pacific Expeditions
22(2):68-297.
Hawaii Department of Land and Natural Resources (HDLNR). 1979. Hawaii
fisheries development plan. Honolulu, HI. 297 pp.
Hawaii Department of Land and Natural Resources (HDLNR). 1980. Hawaii
coastal zone, fisheries management study. Honolulu, HI. 172 pp.
Hayes, S., and D. Halpern. 1976. Observations of internal waves and
coastal upwelling off the Oregon coast. J. Mar. Res. 34:247-267.
Haynes, B.W., and S.L. Law. 1981a. Updated process road maps for manganese
nodule processing. Draft report, U.S. .Bureau of Mines, Avondale Research
Center.
Haynes, B.W., and S.L. Law. 1981b. Predicted physical and chemical
characteristics of manganese nodule processing reject waste materials.
Draft report, U.S. Bureau of Mines, Avondale Research Center.
Haynes, B.W., S.L. Law, and D.C. Barron. 1981. The elemental and
mineralogical description of Pacific manganese nodules. Draft report, U.S.
Bureau of Mines, Avondale Research Center.
Hendricks, T.J. 1975. Properties of Nearshore Currents, pp. 167-172. In:
Coastal Water Research Project Annual Report for the year ended 30 June
1975. SCCWRP, El Segundo, CA.
211
-------
Hendricks, T.J. 1980. Currents in the Los Angeles Area. pp. 243-256. In:
Coastal Water Research Project Biennial Report 1979-1980. SCCWRP, El
Segundo, CA.
Hessler, R.R., and P.A. Jumars. 1974. Abyssal community analysis from
replicate box cores in the central North Pacific. Deep-Sea Res.
21:185-209.
Hickey, B.M. 1979a. The California current system - hypothesis and facts.
Prog. Oceanog. 8:191-279.
Hickey, B.M. 1979b. Direct measurements of the California current system
off Washington. J. Mar. Res. submitted February, 1979.
Hickey, B.M. 1981. Alongshore coherence on the Pacific Northwest
continental shelf (January-April 1975). J. Phys. Oceanogr. 11:822-835.
Hickey, B.M., and P. Hamilton. 1980. A spin-up model as a diagnostic tool
for interpretation of current and density measurements on the continental
shelf of the Pacific Northwest. J. Phys. Oceanogr. 10:12-24.
Hildebrand, H.H. 1954. A study of the fauna of the brown shrimp (Penaeus
aztecus Ives) grounds in the western Gulf of Mexico. Pub. Inst. Mar. Sci.
Univ. Texas 3:229-366.
Hirota, J. 1981. Potential effects of deep-sea minerals mining on
macrozooplankton in the North Equatorial Pacific. Marine Mining 3:19-57.
Hobson, E.S. 1974. Feeding relationships of teleostean fishes on coral
reefs in Kona, Hawaii. Fish. Bull., U.S. 72:915-1031.
Hobson, L.A., and C.J. Lorenzen. 1972. Relationships of chlorophyll maxima
to density structure in the Atlantic Ocean and Gulf of Mexico. Deep-Sea
Res. 19:297-306.
Hopkins, T.L., and R.C. Baird. 1975. Net feeding in mesopelagic fishes.
Fish. Bull., U.S. 73:908-914.
Hopkins, T.L., and R.C. Baird. 1977. Aspects of the feeding ecology of
oceanic midwater fishes, pp. 325-360. In: Oceanic Sound Scattering
Prediction, N.R. Anderson and B.S. Zahuranec, (eds). Plenum Press, New
York, NY.
Houghton, J.P., D.L. Beyer, and E.D. Thielk. 1980. Effects of oil well
drilling fluids on several important Alaskan marine organisms. Presented at
the symposium: Research on Environmental Fate and Effects of Drilling
Fluids and Cuttings. Lake Buena Vista, Florida. January 21-24, 1980.
Hubred, G.L. 1980. Manganese nodule extractive metallurgy review,
1973-1978. Marine Mining 2(3):191-213.
212
-------
Hulburt, E.M., and N. Corwin. 1972. A note on the phytoplankton
distribution in the offshore water of the eastern and central Gulf of
Mexico. Carib. J. Sci. 12:29-38.
Hunt, J.R. 1980. Coagulation in continuous particle size
distributions: theory and experimental verification. Report No. AC-5-80.
W.M. Keck Laboratory of Environmental Engineering Science, C.I.T., Pasadena,
CA. 176 pp.
Huntsman, S.A., and W.6. Sunda. 1981. The role of trace metals in
regulating phytoplankton growth, pp. 285-328. In: The physiological
ecology of phytoplankton, I. Morris, (ed). Blackwell Scientific
Publications, London.
Huyer, A. 1974. Observations of the coastal upwelling region off Oregon
during 1972. Ph.D. Thesis. Oregon State University, Corvallis, OR. 149
pp.
Huyer, A. 1976. A comparison of upwelling events in two locations: Oregon
and northwest Africa. J. Mar. Res. 34:531-546.
Huyer, A. 1977- Seasonal variation in temperature, salinity, and density
over the continental shelf off Oregon. Limnol. Oceanogr. 22:442-453.
Huyer, A., R.D. Pillsbury, and R.L. Smith. 1975. Seasonal variations of
the alongshore velocity field over the continental shelf off Oregon.
Limnol. Oceanogr. 20:90-95.
Huyer, A., and R.L. Smith. 1974. A subsurface ribbon of cool water over
the continental shelf off Oregon. J. Phys. Oceanogr. 4:381-391.
Huyer, A., and R.L. Smith. 1976. Observations of a poleward undercurrent
over the continental shelf off Oregon, May-June 1975. Trans. Am. Geophys.
Union 57:263.
Huyer, A., and R.L. Smith. 1978. Physical characteristics of Pacific
Northwestern coastal waters. In: The marine plant biomass of the Pacific
Northwest coast. R. Krauss, (ed). Oregon State University Press.
Corvallis, OR. pp. 37-55.
Huyer, A., R.L. Smith, and E. Sobey. 1978. Seasonal differences in low
frequency current fluctuations over the Oregon continental shelf. J.
Geophys. Res. 83(C-10):5076-5089.
Ibragim, A.M., and S.A. Patin. 1976. Effect of mercury, lead, cadmium, and
copper on primary production and phytopl ankton in some coastal regions of
the Mediterranean and Red Seas. Oceanology 15:589-591.
Ichiye, T. 1966. Turbulent diffusion of suspended particles near the ocean
bottom. Deep-Sea Res. 13(4):679-685.
213
-------
Ichiye, T., C. Mungall , M. Inoue, and D. Home. 1978. Gulf of Mexico
dispersion calculations, Texas A. & M. University Research Foundation,
Technical Report, ref-78-10-T, 49 pp.
Ichiye, T., M. Inoue, and M. Carnes, 1981. Horizontal diffusion in ocean
dumping experiments. In: Ocean Dumping of Industrial Wastes, B.H. Ketchum,
D.R. Kester, and P.K. Park, (eds). Marine Science, Vol. 12.
Ikehara, W.N. 1981.
Hawaii 1980. final
Honolulu, HI. 9 pp.
A survey of the
Contract Report
+ tables.
ikashibi tuna fishery in the state of
to NMFS, SWFC, Honolulu Laboratory,
Institute of Marine Resources, Scripps Inst. Oceanogr. 1971. Eutrophication
in coastal waters: Nitrogen as a controlling factor. U.S. EPA Water
Pollution Control Research Series, 16010 EHC. 67 pp.
Iverson, R.L., and
production in the
research, pp. 147-211. In
Needs in the Gulf of Mexico
October, 1979. Vol. IIA.
Atmospheric Administration,
T.L. Hopkins. 1981. A summary of knowledge of plankton
Gulf of Mexico: Recent phytoplankton and zooplankton
Proc. of a Symposium on Environmental Research
(GOMEX), Key Biscayne, Florida, 30 September-5
U.S. Dept. Commerce, National Oceanic and
Miami, FL.
Iwamoto, T. 1965. Summary of tuna observations in the
cruises of the exploratory fishing vessel Oregon, 1950-63.
27:7-14.
Gulf of Mexico on
Comm. Fish. Rev.
Jackson, G.A., R.C.Y. Koh, N.H. Brooks, and J.J. Morgan. 1979. Assessment
of alternative strategies for sludge disposal into deep ocean.basins off
southern California. Rep. No. 14. Environmental Quality Laboratory,
California Institute of Technology-, Pasadena, CA.
Jenkins, R.M., M.K. Jugel , K.M. Keith, and M.A. Meylan. 1981. The
feasibility and potential impact of manganese nodule processing in the Puna
and Kohala districts of Hawaii. Draft report, U.S. Department of Commerce,
NOAA, Office of Policy and Planning, Marine Minerals Division^ and State of
Hawaii, Department of Planning and Economic Development. 275 pp.
Johanson, E.E., S.P. Bowen, and G. Henry. 1976. State-of-the-art survey
and evaluation of open-water dredged, material placement methodology.
Contract Rep. D-76-3. U.S. Army Engineer Waterways Experiment Station,
Vicksburg, MS.
Johnson, B.H., and B.W. Holliday. 1978. Evaluation and Calibration of the
Tetra Tech Dredged Material Disposal Models Based on Field Data. Technical
Rep. D-78-47. U.S. Army Engineer Waterways Experiment Station,
Environmental Effects Laboratory, Vicksburg, MS.
Jones, A.A., and D.V. Ellis. 1976.
tailing on marine infaunal benthos.
5:299-307.
Sub-obi iterative effects of mine
Air, Water, and Soil Pollution
214
-------
Jumars, P.A. 1981. Limits in predicting and detecting benthic community
responses to manganese nodule mining. Marine Mining 3:213-229.
Kaakinen, J.W., R.M. Jorden, M.H. Lawasani , and R.E. West. 1975. Trace
element behavior in coal-fired power plant. Environ. Sci. Tech.
9(9):862-869.
Kalil, E.K. 1980. Chemical analysis of drill muds and discharge plumes.
Presented at the Symposium: Research on Environmental Fate and Effects of
Drilling Fluids and Cuttings. Lake Buena Vista, Florida. January 21-24,
1980.
Kamykowski, D. 1973. Some physical and chemical aspects of the
phytoplankton ecology of La Jolla Bay. Ph.D. Thesis. Univ. of California,
San Diego, 269 pp.
Kamykowski, D., and C. Van Baalen. 1979. Phytoplankton and primary
productivity. In: Environmental Studies, South Texas Outer Continental
Shelf, Biology and Chemistry. R.W. Flint and C.W. Griffin, (eds). Final
Report to the Bureau of Land Management, Contract AA550-Ct7-ll.
Kitchen, J.C., D. Menzies, H. Pak, and J.R. Zaneveld. 1975. Particle size
distributions in a region of coastal upwelling analyzed by characteristic
vectors. Limnol. Oceanogr. 20:775-783.
Klein, D.H., A.W. Andren, J.A. Carter, J.F. Emery, C. Feldman, W. Fulkerson,
W.S. Lyon, J.C. Ogle, Y. Talmi, R.I. VanHook, and N. Bolton. 1975.
Pathways of thirty-seven trace elements through coal-fired power plant.
Environ. Sci. Tech. 9(10):973-979.
Klingbeil, R.A., J.S. Sunada, J.D. Spratt. 1980. Review of the pelagic wet
fisheries for 1978 and 1979. CalCOFI Rept. 20:8-10.
Knauer, G.A., and J.H. Martin. 1972. Seasonal variations of cadmium,
copper, manganese, lead, and zinc in water and phytoplankton in Monterey
Bay, California. Limnol. Oceanogr. 18:597-604.
Koh, R.C.Y., and N.H. Brooks. 1975. Fluid mechanics of wastewater disposal
in the ocean, pp. 187-212. In: Annual Review of Fluid Mechanics, Vol. 7.
Annual Reviews, Inc., Palo Alto, CA.
Koh, R.C.Y., and Y.C. Chang. 1973. Mathematical model for barged ocean
disposal of wastes. EPA-660/2-73-029. U.S. EPA, Office of Research and
Development, Washington, D.C.
Koslow, J.A., and A. Ota. 1981. The ecology of vertical migration in three
common zooplankters in the La Jolla Bight, April-August 1967. Biol.
Oceanogr. 1:107-134.
Kramer, J.R., H.D. Grundy, and L.G. Hammer. 1980. Occurrence and
solubility of trace metals in barite for ocean drilling operations.
Presented at the Symposium: Research on Environmental Fate and Effects of
215
-------
Drilling Fluids and Cuttings. Lake Buena Vista, Florida. January 21-24,
1980.
Krishnappan, B.G. 1975. Dispersion of granular material dumped in deep
water. Canada Center for Inland Waters, Inland Waters Directorate.
Burlington, Ontario, Canada. 114 pp.
Kuit, W.A. 1982. The Polaris Mine: Tailings disposal in the high arctic.
Presented at Marine Tailings Disposal Symposium, March 22-23, 1982,
Ketchikan, AK.
Laevastu, T., D.E. Avery, and D.C. Cox. 1964. Coastal currents and sewage
disposal in the Hawaiian Islands. HIG-64-1.
Laevastu, T., D.E. Avery, and D.C. Cox. 1964. Coastal currents and sewage
disposal in the Hawaiian Islands. HIG-64-1.
Lasker, R. 1975. Field criteria for survivaal of anchovy larvae: The
relation between inshore chlorophyll maximum layers and successful first
feeding. Fish. Bui., U.S. 73:453-462.
Lasker, R. 1978. The relation between oceanographic conditions and larval
anchovy food in the California Current: identification of factors
contributing to recruitment failure. Rapp. P.-v. Reun. Cons. in. Explor.
mer 173:212-230.
Lavelle, J.W., and E. Ozturgut. 1981. Dispersion of deep-sea mining
particulates and their effect on light in ocean surface layers. Marine
Mining. 3:185-212.
Lees, D.C., and J.P. Houghton. 1980. Effects of drilling fluids on benthic
communities at the lower Cook Inlet C.O.S.T. well. Presented at the
symposium: Research on environmental fate and effects of drilling fluids
and cuttings. Lake Buena Vista, Florida. January 21-24, 1980.
Leipper, D.F. 1970. A sequence of current patterns in the Gulf of Mexico.
J. Geophys. Res. 75(3):637-658.
Leipper, D.F., J.D. Cochrane, and J.F. Hewitt. 1972. A detached eddy and
subsequent changes (1965). In: Contributions to the Physical Oceanography
of the Gulf of Mexico, L.R.A. Capurro and J.L. Reid, (eds). Oceanographic
Series, Vol. 2, Texas A. & M. University.
Levings, C.D. 1975. Biological reconnaissance of an abandoned mine
tailings disposal area in Toquart Bay, Barkely Sound, B.C. Fisheries
Research Board of Canada. Manuscript Report Series, No. 1362. 6 pp.
Levings C.D., and N. McDaniel. 1973. Biological observations from the
submersible Pisces IV near Britannia Beach, Howe Sound, B.C. Fish. Res.
Bd. Can., Technical Rep. No. 409 23 pp.
216
-------
Leet, W.S., and F.K. Cramer. 1971. Pacific southwest fisheries, pp.
218-233. In: Our Changing Fisheries, S. Shapiro, (ed). U.S. Government
Printing Office Washington, D.C.
Lewbel , G.S., A. Wolfson, T. Gerrodette, W.H. Lippincott, J.L. Wilson, and
M.M. Littler. 1981. Shallow-water benthic communities on California's
outer continental shelf. Mar. Ecol. Prog. Ser. 4:159-168.
Lewin, J., and T. Hruby. 1973. Blooms of surf-zone diatoms along the coast
of the Olympic Peninsula, Washington. II. A diel periodicity in buoyancy
shown by the surf-zone diatom species, Chaetoceros armatum. T. West.
Estuarine Coastal Mar. Sci. 1:101-105.
Lewin, J., J.E. Ekman, and G.N. Ware. 1979. Blooms of surf-zone diatoms
along the coast of the Olympic Peninsula, Washington. XI. Regeneration of
ammonium in the surf environment by the Pacific razor clam Siliqua patula.
Mar. Biol. (Berl.) 52:19.
Lillehagen, N.B. 1980. Bauxite mining by Nabalco Pty. Ltd. at Gove, N.T.
pp. 371-373. In: Mining and metallurgical practices in Australia, J.T.
Woodcock, (ed). The Australasian Institute of Mining and Metallurgy,
Victoria, Australia.
Liss, R.G., F. Knox, D. Wayne, and T.R. Gilbert. 1980. Availability of
trace elements in drilling fluids to the marine environment. Presented at
the Symposium: Research on Environmental Fate and Effects of Drilling
Fluids and Cuttings. Lake Buena Vista, Florida. January 21-24, 1980.
Littler, M.M. 1973. The population and community structure of Hawaiian
fringing-reef crustose Coral!inaceae (Rhodophyta, Cryptonemiales). J. Exp.
Mar. Biol. 11:103-120.
Longhurst, A.R. 1967. Diversity and trophic structure of zooplankton
communities in the California Current. Deep-Sea Res. 14:393-408.
Low, L.L., G.K. Tanonaka, and H.H. Shippen. 1976. Sablefish of the
northeastern Pacific Ocean and Bering sea. Northwest Fisheries Center
Processed Rep. NMFS, NOAA, Seattle, WA. 115 pp.
Luoma, S.N., and G.W. Bryan. 1978. Factors controlling the availability of
sediment-bound lead to the estuarine bivalve Scrobicularia plana. J. Mar.
Biol. Ass. U.K. 58:793-802.
Luoma, S.N., and E.A. Jenne. 1977. The availability of sediment-bound
cobalt, silver, and zinc to a deposit-feeding clam. pp. 213-231.
In: R. Wildung and H. Drucker (eds.), The Biological Implications of Metals
in the Environment. NTIS CONF-750929.
MacCall, A.D., G.D. Stauffer, and J.P. Troudec. 1976. Southern California
recreational and commercial marine fisheries. Mar. Fish. Rev. 38(1)1-32.
217
-------
Maclsaac, J.J., and R.C. Dugdale. 1969. The kinetics of nitrate and
ammonia uptake by natural populations of marine phytoplankton. Deep-Sea
Res. 16:45-57.
Mais, K.F. 1974. Pelagic fish surveys in the California Current. Calif.
Dept. Fish. Game, Fish Bull. 162:79 pp.
Malone, T.C. 1971. The relative importance of nannoplankton and
netplankton as primary producers in the California current system. Fish.
Bull., U.S. 69:799-820.
Mariani, G.M., L.U. Sick, and C.'C. Johnson. 1980. An environmental
monitoring study to assess the impact of drilling discharges in the
mid-Atlantic. III. Chemical and Physical Alterations in the Benthic
Environment. Presented at the Symposium: Research on Environmental Fate
and Effects on Drilling Fluids and Cuttings. Lake Buena Vista, Florida.
January 21-24, 1980.
Marlowe, C.J., and C.B. Miller. 1975. Patterns of vertical distribution
and migration of zooplankton at Ocean Station "P". Limnol. Oceanogr.
20:824-844.
Matsumoto, W.M., T.K. Kazama, and D.C. Aasted. 1981. Anchored fish
aggregating devices in Hawaiian waters. Mar. Fish. Rev. 43:1-13.
Maul, G.A. 1977. The annual cycle of the Loop Current, Part I:
Observations during a one-year time series. J. Mar. Res. 35:29-47.
Maurer, D.L., R.T. Keck, J.C. Tinsman, W.A. Leathern, C.A. Wethe, M.
Huntzinger, C. Lord, and T.M. Church. 1978. Vertical migration of benthos
in simulated dredged material overburdens. Vol. 1: Marine Benthos. Tech.
Rep. D-78-35. U.S. Army Engineer Waterways Experiment Station, Vicksburg,
MS. 97 pp.
Maurer, D., W. Leathern, and C. Menzie. 1981. The impact of drilling fluid
and well cuttings on polychaete feeding guilds from the U.S. northeastern
continental shelf. Mar. Poll. Bull. 12(10):342-347.
May. R.C. 1973. Larval mortality in marine species and the critical period
concept, pp. 2-19. In: The early life history of fish, J.H.S. Blaxter
(ed). Springer-Verlag, Berlin.
McCulloch, W.L., J.M. Neff, and R.S. Cam. 1980. Bioavai1abi1ity of
selected metals from used offshore drilling muds to the clam Rangia cuneata
and the oyster Crassostrea gigas. Presented at the symposium"! ReTearch on
Environmental Fate and Effects of Drilling Fluids and Cuttings. Lake Buena
Vista, Florida. January 21-24, 1980.
McDaniel, N.G. 1973. A survey of benthic macroinvertebrate fauna and solid
pollutants in Howe Sound. Fish. Res. Bd. Can. Tech. Rep. No. 385. 64 pp.
218
-------
National Oceanic and Atmospheric (NOAA). 1975. Ocean dumping in the New
York Bight. Technical Report ERL 321-MESA 2, Boulder, CO.
National Oceanic and Atmospheric Administration (NOAA). 1980. Report to
the Congress on ocean dumping monitoring and research-January through
December, 1978. 42 pp.
Neff, J.W., R.S. Foster, J.F. Slowey. 1978. Availability of
sediment-adsorbed heavy metals to benthos with particular emphasis on
deposit feeding infauna. Tech. Rep. D-78-42. U.S. Army Engineer Waterways
Experiment station, Vicksburg, MS.
Neighbor Island Consultants. 1977. Final Report, Environmental Surveys of
Deep Ocean Dredged Spoil Disposal Sites in Hawaii. Prepared for the U.S.
Army Corps of Engineers Contract No. DACW 84-76-C-0032. Honolulu, HI. 131
pp.
Nelson, W.R., and J.S. Carpenter. 1968. Bottom longline explorations in
the Gulf of Mexico. A report on "Oregon II's" first cruise. Comm. Fish.
Rev. 39:57-62.
Nicholson, W.R. 1978. Gulf menhaden, B r e v o o r t i a pat r o n u s , purse seine
fishery: catch, fishing activity, and age and size composition, 1964-73
NOAA Tech. Rep. NMFS Spec. Sci. Rep. Fish. No. 722.
Nowlin, W.D. 1971. Water masses and general circulation of the Gulf of
Mexico. In: Oceanology International, February 1971, pp. 28-33.
Nowlin, W.D. 1972. Winter circulation patterns and property distributions.
In: Contributions on the Physical Oceanography of the Gulf of Mexico.
L.R.A. Capurro and J.L. Reid, (eds). Vol. 2, Texas A. & M. University
Oceanographic Series.
Okubo, A., and C.C. Ebbesmeyer. 1976. Determination of vorticity,
divergence, and deformation from analysis of drogue observations. Deep Sea
Res. 23:349-352.
Oliver, J.S., P.N. Slattery, L.W. Hulberg, and J.W. Nybakken. 1977.
Patterns of succession in benthic infaunal communities following dredging
and dredged material disposal in Monterey Bay. Tech. Rep. D-77-27,
U.S. Army Waterways Experiment Station, Vicksburg, MS. 186 pp.
Ondov, J.M., W.H. Zoller, N.K. Olmez, G.E. Gordon, L.A. Rancitelli, K.H.
Abel, R.H. Fliby, K.R. Shah, and R.C. Ragaini. 1975. Elemental
concentrations in the National Bureau of Standards environmental coal and
fly ash standard reference materials. Anal. Chem. 47:1102.
Osborn, T.R., and C.S. Cox. 1972. Oceanic fine-structure. Geophys. Fluid
Dyn. 3:321-345.
Pacific Fishery Management Council (PFMC). 1978a. Northern anchovy fishery
management plan. PFMC, Portland, OR. 133 pp. + appendices.
221
-------
Pacific Fishery Management Council (PFMC). 19785. Draft squid fishery
management plan. PFMC, Portland, OR. 160 pp.
Pacific Fishery Management Counci1 (PFMC). 1978c. Fishery management plan
for commercial and recreational salmon fisheries off the coasts of
Washington, Oregon, and California commencing in 1978. PFMC, Portland, OR.
157 pp.
Pacific Fishery Management Council (PFMC). 1979. Draft fishery management
plan for the Dungeness crab fishery off Washington, Oregon, and California.
PFMC, Portland, OR. 93 pp.
Pacific Fishery Management Council (PFMC). 1980. Draft fishery management
plan and supplemental environmental impact statement for the Washington,
Oregon, and California groundfish fishery. PFMC, Portland, OR.
Pacific Fishery Management Council (PFMC). 1981a. Proposed plan for
managing the 1981 salmon fisheries off the coast of California, Oregon, and
Washington. PFMC, Portland, OR.
Pacific Fishery Management Council (PFMC). 1981b. Discussion draft fishery
management plan for the pink shrimp fishery off Washington, Oregon, and
California. PFMC, Portland, OR. 169 pp.
Pacific Fishery Management Council (PFMC). 1981c. Pacific herring fishery
management plan. PFMC, Portland, OR. 129 pp.
Paffenhofer, G.-A. 1972. The effects of suspended "red mud" on mortality,
body weight, and growth of the marine planktonic copepod, Calanus
helgolandicus. Water, Air, and Soil Poll. 1:314-321.
Paine, R.T., and S.A. Levin. 1981. Intertidal landscapes: disturbance and
the dynamics of pattern. Ecol. Monogr. 51:145-178.
Pak, H., and J.R.V. Zaneveld. 1978. Intermediate nepheloid layers observed
over the continental margins off Oregon. SPIE Vol. 160. Ocean Optics V
(1978)
Pak, H., 6.F. Beardsley, Jr=, and P.K. Park. 1970. The Columbia River as a
source of marine light-scattering particles. J. Geophys. Res.
75:4570-4578.
Park, T. 1975. Final report to the Bureau of Land Management on
zooplankton distribution over the Texas shelf. Texas A. & M. Univ., Dept.
of Mar. Biol. 39 pp.
Park, T. 1976. Fourth quarterly report to the Bureau of Land Management on
zooplankton distribution over the Texas shelf. Texas A. & M. Univ., Dept.
of Mar. Biol. 28 pp.
222
-------
Parrish, R.H., C.S. Nelson, and A. Bakun. 1981. Transport mechanisms and
reproductive success of fishes in the California Current. Biol. Oceanogr.
1:175-203.
Parsons, T.R., and R.J. LeBrasseur. 1970. The availability of food to
different trophic levels in the marine food chain, pp. 325-343. In:
Marine Food Chains, J.H. Steele, (ed). Univ. of California Press, Berkeley,
CA.
Patin, S.A., V.N. Tkachenko, A.M. Ibragim, and L.V. Fedotova. 1974. Effect
of some metals on primary production in the coastal zone of the Caspian Sea.
Oceanology 14:72-74.
Pattullo, J., and W. Denner. 1965. Processes affecting seawater
characteristics along the Oregon Coast. Limnol. Oceanogr. 10:443-450.
Patzert, W.C., K. Wyrtki, and H.J. Santamore. 1970. Current measurements
in the Central North Pacific Ocean. HIG-70-31.
Patzert, W.C. 1969. Eddies in Hawaiian waters. HIG-69-8.
Pearcy, W.G., and J.W. Ambler. 1974. Food habits of deep-sea macrourid
fishes off the Oregon Coast. Deep-Sea Res. 21:745-759.
Pearcy, W.G., E.E. Krygier, R. Mesecar, and F. Ramsey. 1977. Vertical
distribution and migration of ocean micronekton off Oregon. Deep-Sea Res.
24:223-245.
Pequegnat, W.E., R.M. Darnell, B.M. James, E.A. Kennedy, L.H. Pequegnat, and
T.J. Turner. 1976. Ecological aspects of the upper continental slope of
the Gulf of Mexico. Prepared for Div. of Minerals Environ. Assessment,
Bureau of Land Management, under Contract No. 08550-CT4-12. 305 pp.
+appendices.
Pequegnat, W.E., D.D. Smith, R.M. Darnell, B.J. Presley, and R.O. Reid.
1978. An assessment of the potential impact of dredged material disposal in
the open ocean. Tech. Rept. D-78-2. U.S. Army Engineer Waterways
Experiment Station, Environmental Effects Laboratory, Vicksburg, MS. 642
pp. plus appendices.
Peterson, W.T., and C.B. Miller. 1975. Year-to-year variations in the
planktology of the Oregon upwelling zone. Fish. Bull., U.S. 73:642-653.
Peterson, W.T., C.B. Miller, and A. Hutchinson. 1979. Zonation and
maintenance of copepod populations in the Oregon upwelling zone. Deep-Sea
Res. 26A:467-494.
Petrazzulo, G. 1981. An environmental assessment of drilling fluids and
cuttings released onto the outer continental shelf for the Gulf of Mexico.
Prepared for U.S. EPA Ocean Programs Branch, Office of Water and Waste
Management and Industrial Permits Branch, Office of Water Enforcement. 2
Vol.
223
-------
Phillips, D.J.H. 1976. The common mussel Mytilus edulis as an indicator of
pollution by zinc, cadmium, lead, and copper. I. Effects of Environmental
Variables on Uptake of Metals. Mar. Biol. (Berl.) 38:59-69.
Poh, K.-K. 1972. Economics and market potential of the precious coral
industry in Hawaii. University of Hawaii Sea Grant UNIHI-SEAGRANT-AR-71-03.
22 pp.
Ralston, S. 1979. A description of the bottomfish fisheries of Hawaii,
American Samoa, Guam, and the Northern Marianas. Report to Western Pacific
Fishery Management Council, Honolulu, HI. 102 pp.
Ramsey, B. 1982. Personal Communication on 1 July 1982. U.S.
Environmental jProtection Agency, Washington, D.C.
Reed, R.K., and D. Halpern. 1976. Observations of the California
under-current off Washington and Vancouver Island. Limnol. Oceanogr.
21:389-398.
Reid, F.M.H., E. Fuglister, and J.B. Jordan. 1970. Phytoplankton taxonomy
and standing crop. pp. 51-66. In: The ecology of the plankton off La
Jolla, California, in the period April through September, 1967. J.D.H.
Strickland, (ed). Bull. Scripps Inst. Oceanogr. Univ. Calif. No. 17.
Reid, F.M.H., E. Stewart, R.W. Eppley, and D. Goodman. 1978. Spatial
distribution of phytoplankton species in chlorophyll maximum layers off
southern California. Limnol. Oceanogr. 23:219-226.
Reid, J.G. 1980. Aspects of effluent water disposal from the Yabulu nickel
refinery of Queensland Nickel Pty. Ltd. Paper presented at AMIC Conference,
September, 1980i
Reid, J.L. 1965. Intermediate waters of the Pacific Ocean. The Johns
Hopkins Press, Baltimore, MD. 85 pp.
Reid, J.L., and R.A. Schwartzlose. 1962. Direct measurements of the
Davidson current off central California. J. Geophys. Res. 67(6):2491-2497.
Reid, J.L., G.I. Roden, and J.G. Wyllie. 1958. Studies of the California
Current system. CalCOFI Progress Report, 1 July 1956-1 August 1958.
Reish, D.J. 1980. The effect of different pollutants on ecologically
important polychaete worms. EPA 600/3-80-053, U.S. Environmental Protection
Agency, Narragansett, RI. 138 pp.
Riley, G.A. 1938. The significance of the Mississippi River drainage for
biological conditions in the northern Gulf of Mexico. J. Mar. Res.
1:60-74.
Riley, G.A. 1967. Mathematical model of nutrient conditions in coastal
waters. Bull. Bingham Oceanogr. Coll. 19:72-80.
224
-------
Roden, G.I. 1964. Shallow temperature inversions in the Pacific Ocean. J.
Geophys. Res. 69:2899-2914.
Roesijadi, G. 1981. The significance of low molecular weight,
melallothionein-1 ike proteins in marine invertebrates: current status.
Mar. Env. Res. 4:167-179.
Rosenberg, R. 1972. Benthic fauna recovery in a Swedish fjord following
the closure of a sulfite mill. Oikos 23:92-108.
Rosenthal, H. 1971. Effects of "red mud" on embryos and larvae of the
herring Clupea harengus. Helgolander wiss. Meeresunters. 22:366-376. (In
German with English abstract).
Rowe, G.T., and D.W. Menzel. 1971. Quantitative benthic samples from the
deep Gulf of Mexico with some comments on the measurement of deep-sea
biomass. Bull Mar. Sci. 21: 556-566.
Rueter, J.G., J.J. McCarthy, and E.J. Carpenter. 1979. The toxic effect of
copper on Osci1latoria (Trichodesmi urn) theibauti i. Limnol. Oceanogr.
24(3):558-5"67:
Salazar, R.C., and R.I. Gonzales. 1973. Design, construction, and
operation of the tailings pipelines and underwater tailings disposal system
of Atlas Consolidated Mining and Development Corporation in the Philippines.
pp. 477-511. In: Tailing Disposal Today, Proceedings of the First
International Tailings Symposium, Tucson, Arizona, 1972. C.L. Alpin and
G.O. Argall, Jr., (eds). Miller Freeman Publications, Inc., San Francisco,
CA.
Salazar, R.C., and R.I. Gonzales. 1973. Design, construction, and
operation of the tailings pipelines and underwater tailings disposal system
of Atlas Consolidated Mining and Development Corporation in the Philippines.
pp. 477-511. In: Tailing Disposal Today, C.L. Alpin and G.O. Argall, Jr.,
(eds). Proceedings of the First International Tailings Symposium, Tucson,
Arizona, 1972. Miller Freeman Publications, Inc., San Francisco, CA.
Santos, S.L., and J.L. Simon. 1980. Response of soft-bottom benthos to
annual catastrophic disturbance in a south Florida estuary. Mar. Ecol.
Prog. Ser. 3:347-355.
Sarmiento, J.L., H.W. Feely, W.S. Moore, A.E. Bainbridge, and W.S. Broecker.
1976. The relationship between vertical eddy diffusion and buoyancy
gradient in the deep sea. Earth Planet. Sci. Lett. 32:357-370.
Sauer, T.C. 1981. Personal communication. Results of Analysis of Six Used
Drilling Fluids from Mid-Atlantic Bioassay Program.
Schafer, H.A. 1980. Characteristics of municipal wastewater. pp. 235-240.
In: Coastal Water Research Project Biennial Report 1979-1980, W. Bascom,
(ed). SCCWRP, Long Beach, CA.
225
-------
Schafer, S. 1981. Widow rockfish: Will booming midwater fishery last?
Pac. Fishing 2(8):45-48.
Schubel, J.R., and A. Okubo. 1972. Comments on the dispersal of suspended
sediment across the continental shelves. In: Shelf Sediment Transport:
Process and Pattern. Dowden, Hutchinson and Ross, Inc., Stroudsburg, PA.
656 pp.
Schwartzlose, R.A. 1963. Nearshore currents of the western United States
and Baja California as measured by drift bottles. CalCOFI Progress Report,
1 July 1960-3 June 1972.
Seapy-, R.R. 1974. Zooplankton. pp. 8-1 through 8-99. In: A summary of
knowledge of the Southern California coastal zone and offshore areas, Vol.
II, Biological environment. M.D. Dailey, B. Hill, and N. Lansing, (eds).
U.S. Dept. Interior, Bureau of Land Management.
Senate Report No. 92-451, 92nd Congress 1st Session. (Nov. 12, 1971). In:
[1972] U.S. code congressional and administrative news. p. 4234-4264.
Shafer, S. 1981. Widow rockfish: Will boom midwater fishery last?
Pacific Fishing 2(9):45-48.
Shepard, F.P. 1963. Submarine geology, 2nd Edition. Harper and Row, New
York. pp. 557-558.
Sheridan, P.F., and A.C. Badger. 1981. Responses of experimental estuarine
communities to continuous chl orination. Est. Coast, and Shelf Sci.
13:337-347.
Siegel, H., and W.E. Rader. 1974. An analysis of biosolid waste from the
Houston Chemical Plant bioheater. Tech. Progress Rep. BRC-Corp. 42-74F.
Simmons, E.G., and W.H. Thomas. 1962. Phytoplankton of the eastern
Mississippi delta. Pub!. Inst. Mar. Sci. Univ. Texas 8:369-398.
Smith, J.N. 1980. Letter dated May 14, 1981, from James N. Smith, Acting
Assistant Administrator for Water and Waste Management, EPA, to Honorable
Norman E. D'Amours, Chairman, House of Representatives Subcommittee on
Oceanography, Committee on Merchant Marine and Fisheries.
Southern California Coastal Water Research Project (SCCWRP). 1973. The
ecology of the Southern California Bight: Implications for water quality
management. Southern California Coastal Water Research Project, El Segundo,
CA. 531 pp.
Stephansson and Richards. 1964. Distribution of dissolved oxygen, density,
and nutrients off the Washington and Oregon coasts. Deep-Sea Res. 11.
Strong, C.R., and S.N. Luoma. 1981. Variations in the correlation of body
size with concentrations of Cu and Ag in the bivalve Macoma balthica. Can.
J. Fish. Aquat. Sci. 38:1059-1064.
226
-------
Sturges, W., and J.P. Blaha. 1976. Western boundary current in the Gulf of
Mexico. Science (Wash., D.C.) 192:367-369.
Sturges, W., and C. Horton. 1981. Circulation in the Gulf of Mexico. In:
Proc. of a symposium on Environmental Research Needs in the Gulf of Mexico,
Key Biscayne, FL, 30 September-5 October 1979. NOAA/ERL, Miami, FL.
Sunda, W., and R.R.L. Guillard. 1976. The relationship between cupric ion
activity and the toxicity of copper to phytopl ankton. J. Mar. Res.
34:511-529.
Sunda, W.G., and J.M. Lewis. 1978. Effect of complexation by natural
organic ligands on the toxicity of copper to a unicellular alga, Monochrysis
lutheri. Limnol. Oceanogr. 23(5):870-876.
Sunda, W.G., D.W. Engel, and R.M. Thuotte. 1978. Effect of chemical
speciation on toxicity of cadmium to grass shrimp, Palaemonetes pugio:
importance of free cadmium ion. Env. Sci. Tech. 12:409-413.
Suszhowski, D. 1982. Personal communication on July 9, 1982. U.S. Army
Corps of Engineers, New York District, New York, NY.
Sverdrup, H.U., and R.H. Fleming. 1941. The waters off the coast of
southern California, March to July, 1937. Scripps Inst. Oceanogr. Bull.
4(10):261-387.
Sverdrup, H.V., M.W. Johnson, and R.H. Fleming. 1942. The oceans: their
physics, chemistry, and general biology. Prentice Hall, Inc., Englewood
Cliffs, NJ. 1,087 pp.
Swartz, R.C., W.A. DeBen, and F.A. Cole. 1979. A bioassay for the toxicity
of sediment to marine macrobenthos. J. Water Poll. Contr. Fed.
51(5):944-950.
Teeter, A.M., and D.J. Baumgartner. 1979. Prediction of initial mixing for
municipal discharges. Rep. CERL-043. U.S. EPA, Corvallis, OR. 88 pp.
Thistle, D., and F.G. Lewis, III. 1981. Literature search on the
soft-bottom benthos of the open waters of the Gulf of Mexico, pp. 31-52.
In: Proc. of a symposium on environmental research needs in the Gulf of
Mexico (GOMEX), Key Biscayne, Florida, 30 September-5 October 1979. Vol.
IIB. U.S. Dept. Commerce, National Oceanic and Atmospheric Administration,
Miami, FL.
Thomas, W.H. 1972. Nutrients, chlorophyll, and phytoplankton productivity
near southern California sewage outfalls. Final Report. SCCWRP, Univ. of
Calif., San Diego, Inst. Mar. Res. Ref. 72-19. 77 pp.
Thomas, W.H., and D.L.R. Seibert. 1977. Effects of copper on the
dominance and the diversity of algae: Controlled ecosystem pollution
experiment. Bull Mar. Sci. 27:23-33.
227
-------
Thompson, J.A.J., and F.T. McComas. 1974. Copper and zinc levels in
submerged mine tailings at Britannia Beach, B.C. Fish. Res. Bd. Can., Tech.
Rep. No. 437. 33 pp.
Thompson, J.A.J., and D.W. Paton. 1978. Copper in sediment interstitial
waters and overlying waters of Howe Sound, B.C. Fisheries and Marine
Service (Canada) Tech. Rep. No. 775. 29 pp.
Thompson, S.H., and E.L. Arnold, Jr. 1971. Gulf of Mexico fisheries, pp.
200-217. In: Our Changing Fisheries, S. Shapiro (ed). U.S. Government
Printing Office, Washington, D.C.
Timagenis, Gr.J. 1980. International control of marine pollution. Oceana
Publications, Inc., New York.
Tully, J.P. 1964. Oceanographic regions and processes in the seasonal zone
of the North Pacific Ocean, pp. 68-84. In: Studies on Oceanography, K.
Yoshida, (ed.). Univ. of Tokyo Press, Tokyo, Japan.
Turner, J.S. 1960. A comparison between buoyant vortex rings and vortex
pairs. J. Fluid Mechanics 7:419-432.
Uchupi , E., and K.O. Emery. 1963. The continental slope between San
Francisco, California and Cedros Island, Mexico. Deep-Sea Res. 10:397-447.
U.S. Environmental Protection Agency (EPA). 1977. Ocean dumping in the
United States-1977- Fifth Annual Report on Administration of Title I, EPA,
Office of Water and Hazardous Materials. Washington, D.C. 65 pp.
U.S. Environmental Protection Agency (EPA). 1977. Ocean dumping. U.S.
EPA, Washington, D.C. Federal Register. Vol. 42, No. 7. p. 2462-2490.
U.S. Environmental Protection Agency (EPA). 1978. Bioassay procedures for
the ocean disposal permit program. EPA-600/9-78-010, U.S. EPA, Gulf Breeze,
FL. 121 pp.
U.S. Environmental Protection Agency (EPA). 1979. Annual report to
Congress, Jan.-Dec. 1978. EPA, Office of Water Programs, Washington, D.C.
33 pp.
U.S. Environmental Protection Agency (EPA). 1980a. Annual report to
Congress, Jan.-Dec., 1979. EPA Office of Water Programs, Washington, D.C.
41 PP.
U.S. Environmental Protection Agency (EPA). 1980b. Environmental impact
statement (EIS) for 106 mile ocean waste disposal site designation. EPA,
Oil and Special Materials Control Division, Washington, D.C.
U.S. Environmental Protection Agency (EPA). 1980c. Final environmental
impact statement (EIS) for Hawaii dredged material disposal sites
designation. Oil and Special Materials Control Division, Marine Protection
Branch, Washington, D.C.
228
-------
U.S. Environmental Protection Agency (EPA). 1981. Standards applicable to
owners and operators of hazardous waste treatment; storage and disposal
facilities. U.S. EPA, Washington, D.C. Federal Register. Vo. 46, No. 100.
P. 28314-28328.
U.S. Naval Oceanographic Office. 1972. Environmental-acoustics atlas of
the Caribbean Sea and Gulf of Mexico, Vol. II, Marine Environment. Naval
Oceanographic Office, Washington, D.C.
Van Cleve, R. 1936. Distribution and early life history of the halibut.
Ph.D. dissertation. Univ. Washington, Seattle, WA. 206 pp.
Vasquez, A.M. 1975. Thesis, Texas A. & M. University.
Venrick, E.L., J.A. McGowan, and A.W. Mantyla. 1973. Deep maxima of
photosynthetic chlorophyll in the Pacific Ocean. Fish. Bull., U.S.
71:41-52.
Waldichuk, M., and R.J. Buchanan. 1980. Significance of environmental
changes due to mine waste disposal into Rupert Inlet. Fisheries and Oceans
Canada, British Columbia Ministry of Environment, Victoria, B.C. 56 pp.
Wastler, T.A. 1981. Ocean dumping permit program under the London Dumping
Convention in the United States. Chemosphere 10(6):659-668.
Western Pacific Fishery Management Council (WPFMC). 1981. Final fishery
management plan for Pacific billfish fisheries of the western Pacific
region. WPFMC, Honolulu, HI. 474 pp.
Westernhagen, H.V., V. Dethlefsen, and H. Rosenthal. 1980. Correlation
between cadmium concentration in the water and tissue residue levels in dab,
Limanda limanda L., and pi a ice, Pleuronectes platessa L. J. Mar. Bio!.
Assoc. "OT 60:45-58.
Williams, A.B. 1958. Substrates as a factor in shrimp distribution.
Limnol. Oceanogr. 3:283-290.
Wilson, K.C., P.L. Haaker, and D.A. Hanan. 1978. Kelp restoration in
southern California, pp. 183-202. In; The marine plant biomass of the
Pacific Northwest Coast, R. Krauss, (ed). Oregon State University Press,
Corvallis.
Wiltshire, J. 1982. Personal communication on February 9, 1982. Univ. of
Hawaii, Dept. of Oceanography. Honolulu, HI.
Winant, C.D., and A.W. Bratkovich. 1981. Temperature and currents on the
southern California shelf:. A description of variability. J. Phys.
Oceanogr. 11:71-86.
Wise, J.P. (ed). 1974. The United States marine fishery resource. Contr.
NOAA-NMFS MARMAP1, 379 pp.
229
-------
Wisner, R.L. 1976. The taxonomy and distribution of lanternfishes (Family
Myctophidae) of the eastern Pacific Ocean. Navy Ocean Res. Dev. Act.,
Rep.-3. U.S. Government Printing Office, Washington, D.C., 229 pp.
Wong, M.H., and F.Y. Tarn. 1977. Soil and vegetation contamination by
iron-ore tailings. Environ. Poll. 14:241-254.
Wong, M.H., K.C. Chan, and C.K. Choy. 1978. The effect of the iron ore
tailings on the coastal environment of Tolo Harbour, Hong Kong. Environ.
Res. 15:342-356.
Woodhead, P.M.J., I.W. Duedall, and N.F. Lansing. 1979. Coal waste
artificial reef program, phase I. EPRI FP-1252, Electric Power Research
Institute, Palo Alto, CA. 65 pp.
Wooster, W.S., and J.H. Jones. 1970. California Undercurrent off northern
Baja California. J. Mar. Res. 28(2):235-250.
Wyatt, B., W.V. Burt, and J.G. Pattullo. 1972. Surface currents off Oregon
as determined from drift bottle returns. J. Phys. Oceanogr. 2:286-293.
Wyllie, J.G. 1966. Geostrophic flow of the California current at the
surface and at 200 m. CalCOFI Atlas #4.
Wyllie, J.G., and R.J. Lynn. 1971. Distribution of temperature and
salinity at 10 meters, 1960-1969, and mean temperature, salinity, and oxygen
at 150 meters, 1950-1968 in the California Current. CalCOFI Atlas No. 15.
Scripps Institution of Oceanography, La Jolla. 188 pp.
Wyrtki, K, V. Graefe, and W. Patzert. 1969. Current observations in the
Hawaiian Archipelago. HIG-69-15.
Yim, W.W.-S. 1976. Heavy metal accumulation in estuarine sediments in a
historical mining of Cornwall. Mar* Poll. Bull. 7(8): 147-150.
Young, D.R., M.D. Moore, G.V. Alexander, T-K. Jan, D. McDermott-Ehrl ich,
R.P. Eganhouse, and P. Hershelman. 1978. Trace elements in seafood
organisms around southern California municipal outfalls. Publ. No. 60,
Southern Calif. Coastal Water Res. Project. 104 pp.
230
-------
APPENDIX A
SUMMARY OF LONDON DUMPING CONVENTION
The overall objective of the London Dumping Convention is to prevent
marine pollution caused by ocean dumping. The Convention requires signatory
states to prohibit the dumping of any wastes or other matter in whatever
form or condition except as otherwise specified. However, the Convention
does not intend to bar any dumping but that of pollutants listed in Annexes
I and II, shown in Tables 36 and 37.
Annex I (Table 36) of the Convention contains those wastes whose
dumping would be prohibited under normal conditions. These wastes include:
organohalogen compounds, mercury and mercury compounds, cadmium and cadmium
compounds, persistent synthetics, oil, high-level radioactive waste and
chemical and biological warfare products. However, these substances may be
disposed of in the ocean if they are rapidly degradable and do not endanger
health or make edible organisms unpalatable. Annex II (Table 37) contains
materials which includes heavy metals, lead, copper, zinc, cyanides,
fluorides, waste containers, and medium- and low-level radioactive wastes.
The rules for the control system established" by the Convention are
contained in Article IV(1). Under this provision it states:
"In accordance with the provisions of the Convention Contracting
Parties shall prohibit the dumping of any wastes or other matter
in whatever form or condition except as otherwise specified
below:
a. the dumping of wastes or other matter listed in Annex I is
prohibited,
b. the dumping of wastes or other matter listed in Annex II
requires a prior special permit,
c. the dumping of all other wastes or matter requires a prior
general permit" (Timagenis 1980).
The major element of the control system is the concept of special and
general permits. A special permit is required for the dumping of matter
listed in Annex II, is required for every single case of dumping, is granted
only upon an application and is subject to the criteria of Annexes II and
III (Tables 37 and 38). A general permit is required for the dumping of all
other matter and may relate to a series of dumping operations, can be issued
without an application (through general regulations) and is subject to the
requirements of Annex III only.
The responsibility and authority for issuing permits is left to the
discretion of States or Parties, except where permits are issued by an
231
-------
TABLE 36. LONDON DUMPING CONVENTION ANNEX I
1. Organohalogen compounds.
2. Mercury and mercury compounds.
3. Cadmium and cadmium compounds.
4. Persistent plastics and other persistent synthetic materials, for example,
netting and ropes, which may float or may remain in suspension in the sea
in such a manner as to interfere materially with fishing, navigation or
other legitimate uses of the sea.
5. Crude oil, fuel oil, heavy diesel oil, and lubricating oils, hydraulic
fluids, and any mixtures containing any of these, taken on board for
the purpose of dumping.
6. High-level radio-active wastes or other high-level radio-active matter,
defined on public health, biological or other grounds, by the competent
international body in this field, at present the International Atomic
Energy Agency, as unsuitable for dumping at sea.
7. Materials in whatever form (e.g. solids, liquids, semi-liquids, gases
or in a living state) produced for biological and chemical warfare.
8. The preceding paragraphs of this Annex do not apply to substances which
are rapidly rendered harmless by physical, chemical or biological processes
in the sea provided they do not:
(i) make edible marine organisms unpalatable, or
(ii) endanger human health or that of domestic animals.
The consultative procedures provided for under Article XIV should be
followed by a Party if there is doubt about the harmlessness of the
substance.
9. This Annex does not apply to wastes or other materials (e.g. sewage
sludges and dredged spoils) containing the matters referred to in para-
graphs 1-5 above as trace contaminants. Such wastes shall be subject
to the provisions of Annexes II and III as appropriate.
10. Paragraphs 1 and 5 of this Annex do not apply to the disposal of wastes
or other matter referred to in these paragraphs by means of incineration
at sea. Incineration of such wastes or other matter at sea requires a
prior special permit. In the issue of special permits for incineration
the Contracting Parties shall apply the Regulations for the Control of
Incineration of Wastes and Other Matter at Sea set forth in the Addendum
to this Annex (which shall constitute an integral part of this Annex)
and take full account of the Technical Guidelines on the Control of
Incineration of Wastes and Other Matter at Sea adopted by the Con-
tracting Parties in consultation.
232
-------
TABLE 37. LONDON DUMPING CONVENTION ANNEX II
The following substances and materials requiring special care are listed for
the purposes of Article VI(l)(a).
A.
C.
D.
E.
Wastes containing significant amounts of the matters listed below:
and their compounds
arsenic
lead
copper
zinc
organosilicon compounds
cyanides
fluorides
pesticides and their by-products not covered in Annex I.
In the issue of permits for the dumping of large quantities of acids and
alkalis, consideration shall be given to the possible presence in such
wastes of the substances listed in paragraph A and to the following
additional substances:
beryllium
chromium
nickel
vanadium
and their compounds
Containers, scrap metal and other bulky wastes liable to sink to the
sea bottom which may present a serious obstac-le to fishing or navigation.
Radio-active wastes or other radio-active matter not included in Annex I.
In the issue of permits for the dumping of this matter, the Contracting
Parties should take full account of the recommendations of the competent
international body in this field, at present the International Atomic
Energy Agency.
In the issue of special permits for the incineration of substances and
materials listed in this Annex, the Contracting Parties shall apply the
Regulations for the Control of Incineration of Wastes and Other Matter
at Sea set forth in the Addendum to Annex I and take full account of
the Technical Guidelines on the Control of Incineration of Wastes and
Other Matter at Sea adopted by Contracting Parties in consultation, to
the extent specified in these Regulations and Guidelines.
233
-------
TABLE 38. LONDON DUMPING CONVENTION ANNEX III
Provisions to be considered in establishing criteria governing the issue of
permits for the dumping of matter at sea, taking into account Article IV(2),
include:
A. Characteristics and composition of the matter
1. Total amount and average composition of matter dumped (e.g. per year).
2. Form, e.g. solid, sludge, liquid, or gaseous.
3. Properties: physical (e.g. solubility and density), chemical and
biochemical (e.g. oxygen demand, nutrients) and biological (e.g. pres-
ence of viruses, bacteria, yeasts, parasites).
4. Toxicity.
5. Persistence: physical, chemical and biological.
6. Accumulation and biotransformation in biological materials or sediments.
7. Susceptibility to physical, chemical and biochemical changes and inter-
action in the aquatic environment with other dissolved organic and
inorganic materials.
8. Probability of production of taints or other changes reducing market-
ability of resources (fish, shellfish, etc.).
B. Characteristics of dumping site and method of deposit
1. Location (e.g. coordinates of the dumping area, depth and distance
from the coast), location in relation to other areas (e.g. amenity
areas, spawning, nursery and fishing areas and exploitable resources).
2. Rate of disposal per specific period (e.g. quantity per day, per
week, per month).
3. Methods of packaging and containment, if any.
4. Initial dilution achieved by proposed method of release.
5. Dispersal characteristics (e.g. effects of currents, tides and wind
on horizontal transport and vertical mixing).
6. Water characteristics (e.g. temperature, pH, salinity, stratification,
oxygen indices of pollution—dissolved oxygen (DO), chemical oxygen
demand (COD), biochemical oxygen demand (BOD)--nitrogen present in
organic and mineral form including ammonia, suspended matter, other
nutrients and productivity).
7. Bottom characteristics (e.g. topography, geochemical and geological
characteristics and biological productivity).
8. Existence and effects of other dumpings which have been made in the
dumping area (e.g. heavy metal background reading and organic carbon
content).
9. In issuing a permit for dumping, contracting Parties should consider
whether an adequate scientific basis exists for assessing the conse-
quences of such dumping, as outlined in this Annex, taking into account
seasonal variations.
C. General considerations and conditions
1. Possible effects on amenities (e.g. presence of floating or stranded
material, turbidity, objectionable odour, discolouration and foaming).
234
-------
TABLE 38. (Continued)
Possible effects on marine life, fish and shellfish culture, fish
stocks and fisheries, seaweed harvesting and culture.
Possible effects on other uses of the sea (e.g. impairment of water
quality for industrial use, underwater corrosion of structures,
interference with ship operations from floating materials, interfer-
ence with fishing or navigation through deposit of waste or solid
objects on the sea floor with protection of areas of special impor-
tance for scientific or conservation purposes).
The practical availability of alternative land-based methods of
treatment, disposal or elimination, or of treatment to render the
matter less harmful for dumping at sea.
235
-------
international authority under Article VI(1) of the Convention. The
Convention contains certain criteria by which the granting of permits is
guided and these criteria are legally binding for the States or Parties,
although in practice they cannot strictly limit their discretion. Any
permit is to be issued only after careful consideration of all factors set
forth in Annex III. However, additional criteria may be established in
national legislation.
The obligation to comply with the criteria and procedures is repeatedly
stressed throughout the Convention in order to impress upon the appropriate
authority the importance of doing so. The Environmental Protection Agency
is the United States authority for implementing the international
requirements for control of ocean dumping, and its statute, the Marine
Protection, Research, and Sanctuaries Act, was amended in 1974 to bring the
Act into conformance with the Convention (PL No. 93-254, 88 Stat. 50, 1974,
33 USC 1401, 1402, 1411, 1412).
236
-------
APPENDIX B
TECHNICAL BASIS FOR METHODS TO PREDICT THE FATE
OF OCEAN DISPOSED PROCESSING REJECTS
INTRODUCTION
Some methods useful in determining the fate of discharged material into
the marine environment are discussed to explain the methodology presented in
Chapter 3 and used in Chapter 6. Limitations on the understanding of the
physical processes are also described. In some instances these limitations
are serious, and may invalidate the results produced by the above
methodologies, as well as those produced by the more complex numerical
models.
OCEAN DUMPING
Disposal of waste material into the ocean using barges results in dumps
of relatively short duration ranging from a few seconds for a split hull
barge to several minutes for a hopper barge. The discussions which follow
consider only instantaneous dumps in water deep enough for the dump material
to be considered as a hemispherical cloud. Dumps in relatively shallow
water where the duration of release is comparable to the time required for
the cloud to impact the bottom are described elsewhere (see Barnard 1978).
If the water depth is not sufficiently great, the plume of waste material
impacts the bottom before equilibrium of the plume and the surrounding
seawater is reached and surges along the bottom.
The physical processes which govern the behavior of the dumped material
in deep water are divided into 3 phases: the convective descent, the
dynamic collapse, and the passive diffusion. The division of the processes
into these three phases is found in the modeling efforts of Koh and Chang
(1973) and Brandsma and Divoky (1976). The plume can be represented as a
hemispherical cloud. During the convective descent, the cloud falls at a
rate determined primarily by its total mass and size and entrains ambient
water. The sizes of the particles which compose the solid portion of the
cloud are of secondary importance during this phase, although recent work on
flocculation (Hunt 1980) suggests that the internal particle size
distribution may change during the descent. The downward force on the cloud
is its negative buoyancy, which decreases as it entrains ambient water. The
resisting forces are primarily due to drag. The dynamic collapse phase
occurs when the cloud has entrained sufficent water so that its density
equals that of the surrounding water. Due to its downward momentum, the
cloud continues to fall past the level of neutral buoyancy entraining water
which results in the cloud becoming positively buoyant. The successive
buoyancy changes produce a rise and fall oscillation about the position of
neutral buoyancy. These oscillations cause the cloud to flatten and behave
237
-------
more and more as individual particles. The passive diffusion phase begins
at this point. The particles are advected by local currents and dispersed
laterally by horizontal diffusion. The particles settle at a rate
determined by their fall velocity and any vertical currents. If the
particle size is small enough, vertical diffusion will alter the particles'
rate of descent. These motions continue until the particle settles on the
sea floor.
The convective descent phase is analyzed in the aforementioned models
by a system of nonlinear first order differential equations. The basis for
this formulation comes, in part, from the papers of Morton et al. (1956) and
Turner (1960). One of the results of the former paper is the formula
max
where:
dm = maximum distance of fall
A = dimensionless constant = 2.66
Vs = volume of cloud
9' =
g = acceleration due to gravity
AP = density of cloud minus density of seawater
P = density of seawater
£ = -1/p dp/dz, normalized density gradient
z = vertical coordinate (positive upward).
A dimensional analysis derivation of this equation is also contained in
Fischer et al. (1979).
For purposes of illustration, the cloud is assumed to be hemispherical
and composed initially of 1/5 manganese nodule processing rejects having a
density equal to 3.19 g/cm3 and 4/5 freshwater with a density equal to 1.00
g/cnr. This mixture is essentially that of the Cuprion process waste slurry
tested by McKibbin (1981). With these assumptions dmax is dependent only on
V. and e. Figure 25 shows the maximum fall distance plotted as a function
of DS (diameter of a hemispherical cloud having volume Vs) for various
values of e.
Typically, the density difference between the ocean water at the
surface and at the pycnocline is several sigma-t units (1 sigma-t unit =
0.001 g/cnr3). For. relatively shallow water depth [e.g., 60 m (197 ft)], the
pycnocline might be at a depth of 40 m (131 ft) or less. Thus, a 2 sigma-t
units density difference gives a value of e= 5 x 10~5/m (1.5xlO"5/ft).
Hence only if the discharge volume of the cloud is less than approximately 6
mj (7.8 ydj) will the cloud reach its equilibrium depth. In the deep ocean
238
-------
Ill
o
150
140
130
120
110
100
90
lao
£7°
S 60
3
5
x 50
S 40
30
20
10
0
€ = 1 x 10~6/m
5 x 10~6/m
1 x 1O~5/m
5x KT5/m
COMPUTATIONS ASSUME CLOUD HAS
INITIAL DENSITY = 1.44 g/cm,
(SOLIDS DENSITY = 3.19 g/cm6
WITH VOIDS RATIO 0.8)
_L
_L
I
I
I
I
I
I
I
3 4 5 6 7 8 9 10 11 12 13
DIAMETER OF HEMISPHERICAL CLOUD (m )
14 15
I I
I
I
I
J
5 10 50 100
VOLUME OF HEMISPHERICAL CLOUD
500
1000
Figure 25. Maximum fall distance for various hemispherical
cloud diameters and normalized density gradients
e when the initial cloud density = 1.44 g/cm
,3
239
-------
the pycnocline may be at 150 m (492 ft) depth. In this case a 2 sigma-t
unit difference gives E a value equal to 1 x 10~5/m (3.0xlO"°/ft). Hence,
clouds having initial volumes up to 230 m3 (301 yd-3) reach equilibrium
depths less than the depth of the pycnocline. Since existing disposal
barges have capacities beyond this range, there is little chance that the
cloud will reach equilibrium for the more shallow depths, but could reach
equilibrium in deeper water if the density gradients above and below the
pycnocline are sufficiently large.
The mining waste slurry densities from other processes have densities
up to 2.00 g/cm3. Figure 26 shows the maximum fall distances assuming an
initial density equal to 2.00 g/cm3. A comparison of these distances with
those previously shown in Figure 25 indicates a cloud of the higher initial
density can have a mass of only 40 percent the mass of the cloud of the
smaller density (1.44 g/cm3) to fall the same distance under the same
oceanographic conditions. This conclusion assumes that Morton's theory is
valid for the heavier cloud. However, some experimental results (Pequegnat
1978) indicate that the heavier cloud, because of its lower initial water
content, may sink with no appreciable entrainment.
The initial dilution achieved by the cloud when it reaches its
equilibrium depth or has initially impacted the bottom is shown in Figure 27
as a function of depth for several dump volumes. These results use the
dynamic descent equations of Brandsma and Divoky (1976) assuming an initial
cloud density of 1.4 g/cm3, and an unstratified ocean having density 1.025
g/cm3. These curves indicate that when the cloud reaches moderately deep
water the initial dilution becomes large as the depth increases, and
consequently concentrations of material contained in the cloud become small.
These results assume a constant entrainment coefficient. However, some
experimental results (Krishnappan 1975) indicate that the entrainment
coefficient eventually becomes very small (even approaching 0). If this is
true, then the high initial dilutions shown above may be overestimated.
Quantitative estimates of the behavior of the cloud during the dynamic
collapse phase are dependent on the exact mathematical formulation in a
particular model. The interested reader should consult Koh and Chang
(1973), or Brandsma and Divoky (1976) for a description of their methods.
The following comments on the passive diffusion phase implicitly assume
that only one particle size is being dispersed. This is permissible since,
although an actual discharged cloud has particle sizes of many different
sizes (and hence fall velocities), particles behave independently at the
inception of this phase (by definition).
Mathematically, passive diffusion of a material is usually described by
the" convective diffusion equations. Solving these equations in three
dimensions and time can, in theory, predict the evolution of the cloud. For
illustrative purposes, convection and diffusion are separated and discussed
independently.
A simple procedure to compute horizontal diffusion of a patch of a
pollutant is to assume that it diffuses radially relative to its center of
240
-------
•• 1 x 10~6/m
5x10 6/m
1 x 10~5/m
5x10"5/m
€= -1. dp.
P dz
COMPUTATIONS ASSUME CLOUD HAS
INITIAL DENSITY = 2.00 g/crn
I
3 4 5 6 7 8 9 10 11 12
DIAMETER OF HEMISPHERICAL CLOUD (m3)
13 14 15
I I
J
I
J_
J
5 10 50 100
VOLUME OF HEMISPHERICAL CLOUD (
500
1000
Figure 26. Maximum fall distance for various hemispherical
cloud diameters and normalized density gradients
e when the initial cloud density =2.0 g/cm .
241
-------
10,000
ro
-P>
ro
O
<
Li.
CC
=)
co
CO
a:
ID
UJ
I
i-
O
UJ
m
Q_
UJ
Q
1,000^
100H
1x10"
5x102 1x103
5x104 1x105
5x103 1x104
INITIAL DILUTION
5x105
1x10u
5x106 1x107
Figure 27. Initial dilutions for instantaneous dumps as a function of depth (based
on convective descent equations of Brandsma and Koh 1976).
-------
mass while the center of mass is transported by the horizontal currents.
This procedure has been incorporated into several models.
In Gaboury and Stolzenbach (1979) for example, the patches are assumed
to be Gaussian (normally distributed) in the horizontal plane. In models
considering vertical variations, the patches can usually be assumed to have
uniform thickness if the sediments in the patch have a uniform fall
velocity. In this case
c(x,y,z,t) =
exp -
(x-x(t))2 (y-y(t))
H(z,t)
where:
c = sediment concentration relative to the ambient
concentration
a = constant
°v » = x,y variances of the distribution
= *,y coordinates of center of mass of patch
H(z,t) = 1 for z(t) _< z _< z2(t)
0 otherwise
= Zl(0) - wft
= zj(0) - wft
= sediment fall velocity.
The variances of the distribution are functions of time, and can be
expressed as
°x = V
°y = CTv
(see Chen et al . , 1975). Chen suggests that the constants a and av be
determined by computing the x and y variances of observed horizontal
currents. Since measurements probably do not exist at any particular site,
an approximation must be used. Gaboury and Stolzenbach use Richardson's 4/3
law to compute:
where:
Lo4/3
a = constant
L0 = initial diameter of the cloud at the trapping depth.
This formula for the x and y variances is used here in subsequent
calculations.
243
-------
In deep ocean dumping, vertical diffusion is often of critical
importance. Horizontal currents may move materials laterally, but if the
particles fall constantly, eventually they are removed from the water
column. The relationship of vertical diffusion to the vertical fall of a
negatively buoyant particle is important in the determination of vertical
position of the particle at a given time. If the vertical diffusion is
"large" in a region, then particles (in a statistical sense) will tend to be
uniformly distributed in the region. If the vertical diffusion is "small,"
then a particle will tend to fall at a rate close to its fall velocity in
quiescent seawater. The relative importance is governed by the parameter
K/wfH
where:
K = vertical diffusivity
= fall velocity of a particle
= thickness of water layer having vertical diffusivity K.
Where K/w^H is large (i.e., much greater than 1), diffusion dominates fall
velocity; while when K/WfH is small (i.e., much less than 1) the converse is
true.
The following computations illustrate what may be expected in the
present situation. The Cuprion process produces wastes having particle
diameters between 1 urn and 74 urn which have (dry) density equal to 3.19
g/cm-3 (McKibbin 1981). Assuming that the seawater has temperature 5° C (41°
F) and salinity 34 ppt, Stokes law gives
wf = 7.14 x 10-5 D2
where :
Wf =
D =
= fall velocity (m/sec)
particle diameter (micrometers).
The vertical diffusivity K can be computed by
K = 4 x *° (Broeker 1981)
IT
where:
K = vertical diffusivity (m3/sec)
N = buoyancy frequency (I/sec)
= (-g/P dp/dz)!/2
g = gravitational acceleration
P = density of seawater
z = vertical coordinate (positive upward).
Table 39 shows the value of K/Hwf for various particle velocities and
244
-------
TABLE 39. VALUES OF K/Hwf FOR VARIOUS PARTICLE FALL VELOCITIES
AND BUOYANCY FREQUENCIES
0
(microns)
1
wf
(m/sec)
7.14xlO-7
N2
(I/sec)
1S-5
io-4
(m2/sec)
4xlQ-4
4x10-°
4x10'°
H = 40 m
140
14
1.4
0.14
K/Hwf
H = 150 m
37
3.7
0.37
0.04
10
74
7.14X10'5
3.91xlO-3
io
-4
10
10
10
10
-7
-6
-5
-4
4x10
-3
4x10
4x10
4x10
4x10
4x10
4x10
-5
-6
-3
-4
-5
-6
1.4
0.14
0.01
0.001
0.03
0.003
0.0003
0.00003
0.37
0.04
0.004
0.0004
0.007
0.0007
0.00007
0.000007
245
-------
buoyancy frequencies of interest. Particles of diameter 10 urn or larger are
affected by vertical dispersion only by the smallest density gradients.
However, particles having diameter 1 urn or so are influenced by diffusive
processes unless the density stratification is fairly strong. Since 50
percent of the material has a grain size less than 6 urn for the Cuprion
processes (McKibbin 1981), roughly this same percentage would be uniformly
distributed in the mixed layer if the material were injected into the layer
in a highly dilute form (for example, from a surface jet).
Several qualifications to the above must be made. First, the upward
vertical current velocities have been ignored. Inclusion of these in the
deep ocean would typically retard the settling rates by 10~7 m/sec. Even
for the 1 urn diameter particle, this would reduce the downward fall velocity
by only 14 percent. However, during a period of coastal upwelling, a
vertical current of 8 x 10"° m/sec would be sufficient to reverse the
negative buoyancy of particles having diameter less than 3.4 urn, and thus
particles of this size or less would tend to rise to the surface unless they
were mixed by vertical diffusion. The other consideration is that the
present papers on which the K/wfH discussion is based (Schubel and Okubo
1972; Lavelle et al., 1981) are single layer models in which the loss to a
lower layer is not relevant or is ignored. This loss rate, which is unknown
at the present time, may influence some of the above conclusions.
The present ocean dumping regulations are primarily concerned with the
fate of the waste materials 4 hours after discharge. Even if the cloud
impacts the bottom, only sand size or larger particulates are likely to have
settled, and the finer particulates will be transported and diffused for
much longer times. A procedure is developed to estimate the horizontal
area, dilution, and average material thickness of the waste material, if it
is assumed that it settles completely within 4 hours time. The convective
descent equations of Brandsma and Divoky (1976) are used to predict dilution
and (hemispherical) cloud radius as a function of water depth. At each
depth, the cloud is allowed to horizontally disperse using the binormal
distribution with the variance dependence of Gaboury and Stol zenbach (1979).
Four hours after the trapping level is reached, the horizontal "area" of the
cloud is computed and is equal to Tra^2. Inspection of the formula for h
previously given shows that the "area is independent of the ambient current
speed. The dilution is computed as the product of the dilution achieved
during descent times the ratio of the "area" after 4 hours time to the area
of the horizontal projection of the cloud at the end of the descent phase.
The thickness is computed by dividing the initial volume of the dump by the
"area" and multiplying this by the ratio of the relative initial density
(with respect to seawater) of the cloud by the relative density of the solid
material. Here, this density is assumed to be 3.4 g/cm3. Figure 28 shows
the "area" as a function of water depth for seven initial cloud volumes
ranging from 200 m3 to 5,000 m3 (262 yd3 to 6,540 yd3). Although an initial
cloud density of 1.4 g/cm3 is used, the areas are almost independent of
initial cloud density having reasonable values. Figure 29 shows the 4 hours
dilution as a function of water depth for the seven initial cloud volumes.
These dilutions are also essentially independent of initial cloud density.
Figures 30 and 31 show the material "thickness" for initial cloud densities
equal to 2.0 g/cm3 and 1.4 g/cm3 respectively.
246
-------
100
50
10
CM
cc
<
.5
.05
.01
.005
- V=5000m3
V=4000m3
V= initial volume of dump
•V=3000m3
•V=2000m3
•V=1OOOm3
•V=500m3
-V=200m3
I I I I I I III L I I I I I I I I
10
5O XX) 500 10OO
WATER DEPTH (M)
5000 1OOOO
Figure 23. Horizontal area covered by instantaneous dump
cloud 4 hours after dumping as a function of
trapping level.
247
-------
1000
500 -
V= initial volume of dump
V=200m3
V=5OOm3
V = 1000m3
V= 2000m3
V=300Om3
V=40OOm3
V= SOOOm3
50 100
500 1000
5000 10000
WATER DEPTH (M)
Figure 29. Dilution achieved by instantaneous dump cloud
4 hours after dumping as a function of trapping
level.
248
-------
1000
500
100
50
10
5
2 5
-------
1000
500 -
100
3E
5
v>
to
ui
XL
U
I
V = 5000m3
= 4000m3
= 3000m3
= 2000m3
= 1000m3
= 500m3
V=200m3
V = initial volume of dump
50
100
500 100O
5000 10000
WATER DEPTH (M)
Figure 31. Thickness of sediment layer if the solids
suspended in the dump cloud were to fall
uniformly in the horizontal cloud area after
4 hours time (initial cloud density = 1.4 gm/cm )
250
-------
Before using these results, several comments are in order. The density
stratifications observed in the oceans in the regions of interest are
rarely, if ever, sufficiently strong to trap a descending cloud at depths
less than 100 m (328 ft). For depths less than this, the cloud impacts the
bottom and a density surge forms. Since this surge is not considered, the
predictions of "area" is probably low while the thickness is probably high.
As the water depth increases the downward velocity decreases and the
strength of the density surge decreases. In waters sufficiently deep and
stratified to trap the cloud, two problems arise. The dynamic collapse
phase, in which the cloud "flattens" out, has been neglected. Also, as
mentioned previously, there is evidence that the entrainment rate eventually
decreases (Kn'shnappan 1975). If this were to occur, then the cloud radius
and dilution would be smaller at the larger depths. These two effects tend
to offset each other, but a quantitative estimate of the combined effect is
not possible at this time. The passive dispersion phase has also been
extensively simplified. The "thickness" is the depth to which the solids
would eventually settle if confined to the "area." Since 4 hours = 1.4 x
10 sec, only particles having diameter greater than 100 urn would settle 1
meter during this time. In view of these difficulties, the predictions are
not accurate enough to compare with field experiments, but should give a
qualitative sense for the effects of oceanographic conditions and dump
strategies.
Predictions using the preceding figures requires the calculation of the
trapping level. This can be accomplished in shallow water using the linear
stratified results presented in Figures 25 and 26, or in general using the
convective descent equations in Brandsma and Divoky (1976). In the presence
of no ambient current and no particle losses within the cloud these become:
2 7rag(P- P ) - 0.5 P Cn
I a aD
/TTa2\|w|w
V~2/M
d_ /2 » a (pa(0)-P)\- E (pa.(0)-pa)
where:
E = 2ira2 a Iwl
a = (hemispherical) cloud radius
P = cloud diameter
w = vertical cloud velocity
g = acceleration due to gravity
a(z) = ambient density
z = vertical coordinate (+ downward)
251
-------
5;: S.5
a = 0.235 (no vorticity assumed)
The trapping depth predictions in Chapter 6 are computed using a computer
program which integrates the above equations using a trapezoidal rule
scheme.
The fate of materials for times greater than 4 hours is also of
interest. Consider first the case in shallow and intermediate depth waters
where an instantaneous dump does not reach its equilibrium level before it
impacts the sea bottom. On impact a density surge is created which, on a
horizontal bottom, will spread radially about the point of impact. The
initial thickness of the surge is difficult to estimate, but should easily
be on the order of meters, not less. If the sediment fall
velocity-exceedence probability distribution of the Cuprion process
(McKibbin 1981) is representative of manganese nodule processing rejects,
then roughly half of the solids will settle to the bottom in a few days time
or less. If the average horizontal current speed were but 0.2 cm/sec, which
is far smaller than most oceanic currents, then particles would travel only
a few kilometers at best. But roughly one half of the solids have diameters
6 urn or less. For the above current speed, these particles would travel 10
km or more for every 1 m above the bottom. Thus the larger fraction would
settle out within a few knr but the smaller diameter fraction would settle
out within tens, if not hundreds of km .
The other possibility is that the wastefield reaches neutral buoyancy
somewhere in the water column. For an instantaneous dump this level may be
near the thermocline but is probably well below it. The equilibrium level
for a continuous discharge near the surface is likely to be well above the
thermocline. A 38 urn diameter particle takes 116 days to fall 100 m (328
ft). In this time the particle travels 100 km if- the average horizontal
current equals 1 cm/sec. Smaller particles would travel much further.
Hence the smaller particles which compose most of the waste travel
tremendous distances in deep water. By then, however, horizontal diffusion
would have scattered the particles over such large areas that the thickness
would be very small (less than 0.001 mm = 10"5 m).
These conclusions neglect effects of vertical dispersion and
biotransformations of suspended solids. Vertical dispersion retards the net
settling rate of fine particles, especially above the thermocline.
Zooplankton, however, ingest fine suspended particles and remove them by
emitting fecal pellets of much larger diameter and hence higher fall
velocity. The net effect of these two mechanisms is unknown. Below the
thermocline, the zooplankton populations decrease exponentially with depth
and the fecal pellet production becomes negligible. In deeper waters the
settling time determinations are probably small due to the neglect of
vertical dispersion.
252
-------
PUMP DOWN
The dilutions achieved in the convective descent phase depend on a
number of variables. The total flow, the output pipe diameter, the vertical
angle of the pipe to the horizontal, the initial density of the jet as well
as the ambient density stratification are all important in determining the
trapping level and dilution of the jet. Hence, adequate predictions for the
range of possible values for each of the above would require a moderately
large number of figures, which is inconsistent with the level of detail
contained elsewhere in this document. Thus no predictions for dynamic
descent phase appear here.
Horizontal diffusion of a patch of suspended solids can more
practically be computed using the method of Brooks (1960) for a line source.
The horizontal diffusion constant e0 is given by
= a
4/3
= cm^/sec
where:
a = constant
= 0.0015-0.049 cnr'-Ysec (Koh and Brooks 1975)
= 0.01 cm^/sec commonly
LQ = initial width of the wastefield
Brooks computes, using a one dimensional convective diffusion equation, that
L_
1 + 2 B x_
3 Lo
3/2
— = erf
o
1/2
1.5/HI+ |6M -i
where:
L = "width" of wastefield at distance x downcurrent
cQ = initial waste material concentration
c = centerline waste material concentration at distance
u = average current speed
253
-------
erf(a) = error function =
-2
dz
The travel time t can be calculated by
t = x/u
Hence the ratios L/L and C/CQ are functions of aL0~2/3t only. These ratios
are shown in Figure 32.
Quantitative estimates of the area over which the solids may settle can
be obtained by integrating the L/LQ equation of Brooks (1960):
5/3
A(t) = u
20a
5/2
- 1
where:
A = area
L = "width" of the wastefield at distance x downcurrent
L0 = initial source width
u = average current speed
a = constant
t = travel time
The area influenced by a continuous discharge of an initial width at
the end of 4 hours time is shown in Figure 33 for various current speeds and
with a= 0.01 cm2/3/sec. As can be seen from this figure, the area impacted
is relatively small unless the initial width (i.e., the jet width at the
trapping level) is large or the ambient currents are large. It must be
observed that little, if any, of the silt or clay particles will settle to
the bottom during 4 hours time. The long term fate of continuously
be obtained. Figures 34 and 35 show areas as a
(1 dimensional) current speeds equal to 0.001
m/sec and 0.01 m/sec rsspectively. In developing these curves a minimum
value of a (0.0015 cm2/3/sec), as reported by Koh and Brooks (1975) for
depths up to 300 m (1,000 ft), is used and hence the areas computed are
minimal with respect to a. These curves indicate that the area becomes less
dependent on the initial source width, LQ, as time increases. Both of these
figures indicate that for times exceeding 20 or 30 days the areas are on the
order of 100 or more km2. In developing these curves it is assumed that the
material begins to settle immediately and that the thickness of the settling
material is uniform. Actually, thicknesses are larger than the average for
small settling times and smaller for large settling times.
discharged material can also
function of time for average
254
-------
1000
X
o
o
o
ro
en
en
10-
1.0
10
100
1000
PARAMETER 8 x Lo 2/3t
Figure 32. Width to initial width (L/Lo) and centerline concentration to initial
centerline concentration (c/co) ratios.
-------
too
50 -
10
CM
Z .5
a.
.05
.01
.005
• u=.1m/s
I III MM!
I _L I I I 11
1 I I J I I I I
10
SO 100
500 1000
WIDTH (M)
Figure 33. Area influenced by a continuous discharge
after 4 hours time.
256
-------
10,000
5,000 -
1,000
500
LII
tr
100
50
10
5
10
50 100 500 1,000
TIME (hours)
5,000 10,000
Figure 34. Area as a function of time for average current
speed = 0.001 m/sec for various initial widths
between 10 and 1,000 m.
257
-------
50 100 500 1,000
TIME (hours)
5,000 10,000
Figure 35. Area as a function of time for average current
speed = 0.01 m/sec for various initial widths
between 10 and 1,000 m.
258
-------
In the event that the suspended particles are in a layer above the
bottom, the minimum time to first impact the bottom must also be considered.
If a layer of thickness T is composed of particles having fall velocity Wf
and the bottom of the layer is at a height H above the sea floor, then the
area over which particles will settle can be computed by
A (t + dt) - A (t)
where:
t»-ti-
wf
dt = i
wf
Assuming an initial width equal to 100 m, Figures 36 and 37 show these areas
as a function of time t for average current speeds of 0.001 m/sec and 0.01
m/sec respectively. The times dt shown range from 10 to 10 seconds. From
Stokes Law, the times required for a 121 urn, 38 urn, 12 urn, 3.8 urn diameter
particle to fall 1 m are 104, 105, 10°, and 10' seconds. An examination of
these figures shows that the larger particles may fall within small areas,
but the fine particles having diameter greater than 12 urn fall within large
areas regardless of the initial height above the seabed. Since longitudinal
diffusion is ignored in Brooks' method, these areas are underestimated.
259
-------
10
50 100 500 1,000
TIME(HRS)
5,000 10,000
10N: TIME (SECONDS)
PARTICLES CONTINUOUSLY
SETTLE ON THE SEA FLOOR
Figure 36. Areas impacted by sediment first encountering
the seafloor at a given time (horizontal current
speed is 0.001 m/sec).
260
-------
10,000
5,000 -
SO 100 500 1,000
TIME(HRS)
5,000 10,000
10N: TIME (SECONDS)
PARTICLES CONTINUOUSLY
SETTLE ON SEA FLOOR
Figure 37. Areas impacted by sediment first encountering the
seafloor at a given time (horizontal current
speed is 0.01 m/sec).
261
-------
APPENDIX C
CHARACTERISTICS OF WASTES SIMILAR TO MANGANESE
NODULE PROCESSING REJECTS
This appendix presents a review of data describing wastes similar to
manganese nodule processing rejects. A summary of this information has been
presented in Chapter 5. A discussion of observed environmental effects
related to some of these operations is presented in Chapter 7.
MINE WASTE DISCHARGES
Marine disposal of mining tailings and processing wastes is not
uncommon in areas where ore bodies lie near the coast (Down and Mill 1978).
A list of these operations for which any information is available is given
in Table C-l. Although marine disposal is not uncommon, results of the
literature search performed during this study substantiate the statement of
Down and Mill (1978, p. 429) that "It must be regretted that although
numerous examples of marine disposal exist, the literature is extremely
sparse, and a freer interchange of data would undoubtedly be beneficial."
For this reason, information in addition to that given in Table 40 is not
immediately available for some of the mining operations listed.
Detailed information is available for the following types of mining
operations: copper and copper-molybdenum, iron, lead-zinc, nickel
processing, bauxite, and potash. Each of these types of mining operations
will be reviewed below under a separate heading. Characteristics of
tailings and processing wastes vary greatly between sites. The data in
Table 41 illustrates that considerable between-site variation may exist in
the grain size composition of tailings, even for similar types of ores. The
proportion of residual metal in the tailings may also vary greatly (Table
42). Causes of between-site variations include differences in the type of
ore, grade of ore, chemical bonding within the ore, and the mining and
processing technique used at each site.
Copper Mines
The Island Copper Mine on Rupert Inlet, British Columbia (Figure 38)
began operation in 1971 (Evans et al., 1972). Copper and molybdenum are
separated from the ore by flotation, producing about 30,000 tons per day of
tailings (Evans and Poling 1975). The Island Copper Mine effluent is 40 to
50 percent solids by weight (Goyette and Nelson 1977), with approximately 70
percent of the solids less than 74 urn in diameter (Figure 39). Before
discharge into Rupert Inlet, effluent is diluted with seawater drawn from a
depth of 15 m (49 ft). The diluted effluent is then discharged at a depth
of 50 m (164 ft) through a submarine outfall which extends 180 m (60 ft)
offshore (Evans and Poling 1975).
262
-------
TABLE 40. EXAMPLES OF MARINE DISPOSAL SYSTEMS
Company & Location
Tailings Quantity
(dry tons/day) &
Type
Disposal Method Deposition Point
Utah Mines, Ltd.,
Island Copper
Mine, Vancouver Is.,
B.C.3
Anaconda, Bri-
tannia Mine,
Britannia Beach,
B.C.5
Cowichan Copper Co.,
Ltd., Sunro Mine,
Jordan River,
Vancouver Is., B.C.a
Atlas Consolidated
Mining & Develop-
ment Corp., Cebu,
Philippines3
El Salvador Copper
Mine, Chanaral,
ChileC
Folldal Verk A/S,
Repparfjord Mine,
Norway3
Ma On Shan Mine,
Hong Kongd
Kennedy Lake Mine,
British Columbia6
Greenex A/S, Greenex
Mine, Greenland^
Nabalco Pty., Ltd.,
Gove Joint Venture,
Australia9
30,480 Cu
Outfall pipe
3,000 Cu
(ceased oper-
ation 1975)
1,525 Cu
(ceased oper-
ation 1974)
68,670 Cu
25,000 Cu
1,600 Cu
? Fe
? Fe
(ceased oper-
ation 1968)
1,400 Pb-Zn
2,700 Red Mud
Outfall pipes
Outfall pipe
Outfall pipe
Canal to shore
Outfall pipe
Dumping at
shore
Outfall pipe
Outfall pipe to
red mud pond;
supernatant
liquor to sea
Rupert Inlet.
250 m offshore
45 m depth
Howe Sound.
Intertidal
Strait of Juan
de Fuca. 300 m
offshore, 3 m
depth
Tanon Strait, Ibo
Point. 490 m off-
shore, 9 m depth
Chanaral Beach,
1938-1974; Caleta
Palito, 1975 -
present
Fjord. Offshore,
50 m depth
Tolo Harbor.
Nearshore
Toquart Bay.
Nearshore
Agardlikavsa Fjord,
25 m depth
Drimmie Arm.
Nearshore
263
-------
TABLE 40. (Continued)
Amax/Kitsault
Molybdenum Mine,
Alice, Arm, ,
British Columbia
Cleveland Potash,
Ltd., Boulby, York-
shire, United King-
dom3
British Aluminum Co.
Ltd., Marseille,
France2
12,000 Mo
4,200 (94% as
salts in solu-
tion)
2,000-3,000
Fe
Outfall pipe
Outfall pipe
Near the head of
Alice Arm, 110 m
offshore, 50 m depth
North Sea. 1820 m
offshore, 25 m
depth
Mediterranean Sea,
2000 m offshore,
350 m depth
Polaris Mine,
Little Cornwall is
Island, Northwest
Territories,
Canada1'
Lead - Zinc Thickened
(Commenced Nov., tailings pulp
1981) discharged
through outfall
Super-saline
lake discharging
to marine waters
Societe Minere et
Metallurgique de
Penarroya, S.A.
Roberto Mill, Car-
tagena, Spain3
Marcopper Mining
Corp., Marinduque,
Philippines3
6,100 Pb-Zn-
Fe
Outfall pipe
Near Portman Bay
25,400 Cu
Outfall pipe
Calancan Bay.
2440 m offshore,
5 m depth
Yabulu Nickel
Refinery, near
Townsville,
Queensland, Australia
Nickel Laterite
17,500 M3/day
of liquid waste
after tail ings
settling
Outfall pipe
Halifax Bay,
2000 m offshore
264
-------
TABLE 40. (Continued)
Fosdalens Bergverks
A/S, Malm, Norway9
Norsk-Neflin,
Stern0y Mine,
Norway3
510 magnitite-
pyrite
400 syenite
Fe203
Coarse tailings
barged offshore;
fine tailings
laundered to
shore
Outfall pipe
Fjord. Offshore at
60 m depth & near-
shore
Altafjord at
shallow depth,
650 m water depth
a Data from Table 2 of Down and Mill (1978).
b Goyette (1975).
c Castilla and Nealler (1978).
d Wong et al. (1978).
e Levings (1975).
Indian and Northern Affairs, undated.
9 Baseden (1976).
Burling, Mclnerney, and Oldham (1981).
1 Kuit (1982).
J' Reid (1980).
265
-------
TABLE 41. SIZE FRACTIONS OF TAILINGS FROM VARIOUS MINES'
Tailings Source Mesh Openings (urn)
Pebble phosphate mine, Florida, U.S.A.
Taconite mine, U.S.A.
Taconite mine, U.S.A.
Cu Mine, U.S.A.
Pb/Zn mine, U.S.A.
21 gold mines, California, U.S.A.
Cu mine, Michigan, U.S.A.
Pb/Zn flotation tails, U.S.A.
Limestone (sand tails), U.S.A.
Pb/Zn mine, U.S.A.
Iron ore mine, Quebec
4 Cu mines, British Columbia, Canada
3 Mo mines, British Columbia, Canada
Cu/Fe mine, British Columbia, Canada
W mine, British Columbia, Canada
Cu/Mo mine, British Columbia, Canada
Fe mine, British Columbia, Canada
5 Cu mines, U.S.A.
Au mine, South Africa
Pb/Zn mine, Germany
Tin mine, Cornwall, U.K.
44
208
74
44
74
44
74
44
150
351
74
147
147
74
74
74
74
43
74
74
295
74
74
74
43
74
60
75
Percent Not Retained
97
"most"
46.5
31
87
73
90
86
3.9-99
50
48
39
99
20-89
10
60-66
40-70
56
55
45
90
45
70
6.1-59
6.7-15
56.7
50
60-66
.2
.5
.3
Data from Table 3 of Down and Stocks (1977).
266
-------
TABLE 42. RESIDUAL METALS IN RECENT TAILINGS SAMPLES9
Type of Tail ings
Pb/Zn, U.S.A.
Cu, U.S.A.
Taconite, U.S.A.
PO Slimes, U.S.A.
Red Muds, U.S.A.
Uranium, U.S.A.
Cu, British Columbia
Pb/Zn, British Columbia
»
Cu/Mo, British Columbia
Cu/Fe, British Columbia
Ni/Cu, British Columbia
Residual
Pb
Zn
Fe
Cu
TiO
Fe
P?0c
AlpO
Fe
U308
V
Cu
Pb
Zn
Sn
Ni
Fe
Mo
Pb
Zn
Fe
Cu
Fe
Mo
Cu
Fe
Cu
Ni
Metals (% by wt.)
0.13 - 0.17
0.18 - 0.41
3.04 - 10.73
0.02 - 0.37
0.02 - 2.0
15-20
9 - 17
3 13-26
10.7 - 52.5
0.045
0.3 - 0.5
0.04 - 0.1
0.01 - 0.06
0.01 - 0.55
0.01
0.1
0.1 - 10.0
0.01
0.1
0.1
20.0
0'.005 - 0.04
2.0
0.03 - 0.04
0.06
12.0
0.04
0.2
a Data from Table 4 of Down and Stocks (1977).
267
-------
IN3
CTl
oo
REFERENCE: Goyette and Nelson, 1977
Figure 38. Location of the Island Copper Mine and submarine outfall into Rupert
Inlet, British Columbia.
-------
100
o
£75
V)
z
HI
u
-------
Monitoring data for the Island Copper Mine discharge are maintained by
the Province of British Columbia, Ministry of the Environment. Data for
1979 were selected from those provided by the Ministry3 to characterize the
chemical composition of the waste discharge. Mean concentrations and ranges
of metals in the discharged solids are given in Table 43, while Table 44
shows the concentrations of dissolved metals in the liquid fraction of the
effluent.
Copper was also mined in British Columbia at the Britannia Mine on Howe
Sound (Figure 40). The mine operated from 1899 to 1975 and produced 3,000
tons per day of tailings (Goyette 1975). Tailings were discharged into Howe
Sound through two outfall pipes located within the intertidal zone (Goyette
1975), while acid mine waters were discharged into Britannia Creek, which
carried them into Howe Sound (Thompson and McComas 1974). Detailed
information on the physical and chemical characteristics of the tailings and
acid mine wastes prior to discharge were not available at the time of this
writing.
The third copper mine for which detailed information is available is
the Jordan River Mine, located on the north shore of the Strait of Juan de
Fuca (Figure 41). This mine operated intermittently from 1960 to 1974, the
most recent operational period being 1972 to 1974 (Ellis 1978). During the
first three operational periods (1960-1972) the mine discharged 1,525 tons
of tailings daily to a location 900 m (3,000 ft) offshore at a depth of 12 m
(40 ft) (Down and Mills 1978, Ellis 1978). Following a pipe failure,
tailings were discharged 300 m (1,000 ft) offshore at a depth of 0-3 m (0-10
ft) below the low tide mark (Ellis 1978). This shallow discharge was in
operation during the last period of mine operation from 1972-1974 (Ellis
1978). Details of the physical and chemical characteristics of the mine
wastes prior to discharge were not available at the time of this writing.
One of the largest copper mining and milling operations which
discharges tailings to the marine environment is the Atlas Mining and
Development Corporation, located on the island of Cebu, the Philippines.
This operation has a milling capacity of about 70,000 tons of ore per day,
from which about 35,000 tons of tailings are produced daily from two
concentrators, Dascon and Bigacon (Salazar and Gonzales 1973). The tailings
effluent is pumped through four separate outfall pipes to a common location
off Ibo Point, on Tannon Strait (Salazar and Gonzales 1973). The four
outfall pipes extend 490 m (1,600 ft) offshore at a depth of 9 m (30 ft)
below the surface. Water depth at the point of discharge is 30 m (100 ft).
The tailings slurry is about 40 to 50 percent solids by weight, and has
a pH of 7.6 to 7.8. The solids have a specific gravity of 2.65 (Salazar and
Gonzales 1973). Grain size distribution of the tailings is given in Table
46. At the time of this writing, no additional information on the physical
or chemical characteristics of the tailings effluent were available.
Letter from Dr. M.J.R. Clark, September 28, 1981.
270
-------
TABLE 43. ISLAND COPPER MINE DISCHARGE
CHEMICAL COMPOSITION OF THE SOLID PHASE (1977 DATA)
As
Cd
Cr
Cu
Fe
Hga
Mna
Mo
Ni
Pb
Zn
Number of
Observations
5
6
6
6
2
3
3
3
1
6
6
Average
Concentrations
mg/kg
4.1
0.23
8.6
248
16,400
0.0017
209
9.1
9.3
5.1
34.1
Range
2.2 to 6
0.14 to 0.3
4.9 to 13.9
170 to 370
15,800 to 17,000
<0. 00005 to 0.005
78 to 325
5.4 to 15.8
3.9 to 6.7
26.9 to 49.9
a Data from 1980.
Reference: Letter from Dr. M.J.R. Clark, September 28, 1981.
271
-------
TABLE 44. ISLAND COPPER MINE DISCHARGE
CHEMICAL COMPOSITION OF LIQUID FRACTION (1979 DATA)
Al
As
Cd
Co
Cr
Cu
Fe
Hg
Mn
Mo
Ni
Pb
Zn
Number of
Observations
1
54
57
45
47
57
47
52
45
55
46
57
49
Average
Concentrations
ug/l
1,030
40
1.1
1.2
11
56.9
0.11
1.6
153
1.5
2.5
6.8
Range
14 to 88
<0.1 to <0.5
<0.1 to 4
0.6 to <5
3 to 280
8 to 1,200
<0.1 to 0.24
1 to 4
100 to 300
<1 to <10
<1 to 5
0.8 to 170
Reference: Letter from Dr. M.J.R. Clark, September 28, 1981.
272
-------
SOUAMISM
I I I
0 1 2
2 3 4 s^t^^^X**®
I'll MILES
~1 T~~l KILOMETERS
345
REFERENCE: Goyette, 1975.
Figure 40. Location of the Britannia Mine on Howe Sound,
British Columbia.
273
-------
ro
10
-I MILES
—| KILOMETERS
10
N
PORT ANGELES '''•'•'.'•': ^y/V.-y-.;'.1-' :V-;/:V • '
REFERENCE: EIHs, 1978.
Figure 41. Location of the Jordan River Mine, British Columbia.
-------
TABLE 45. SIZE DISTRIBUTION OF TAILINGS SOLIDS FROM THE DASCON AND
BIGACON CONCENTRATORS AT CEBU, PHILIPPINES3
Particle Size
(micrometers)
297
210
149
74
44
Less than 44
Average
Da scon Tailings
11.2
18.5
26.4
43.1
49.9
100.0
Percent Retained
Bigacon Tailings
13.0
22.6
33.2
50.6
58.9
100.0
Adapted from Salazar and Gonzales (1973).
275
-------
Several additional mining operations are located in the Philippines
which discharge indirectly via rivers or directly to marine waters; No
published information describing these operations is available however.
At the El Salvador Copper Mine in Chile, two nearshore sites have been
used for the disposal of mine tailings (Figure 42). The first site at
Chanaral Beach was in use from 1938 to 1974. Thereafter, tailings were
discharge into the second disposal area at Caleta Palito, a practise which
continues to the present (Castilla and Nealler 1978). About 25,000 tons of
tailings are transported per day to the disposal area via a tailings canal.
Wastes carried by the canal include flotation tailings from copper and
molybdenum concentration plants and treated domestic wastewaters from the El
Salvador Sewage treatment plant (Castilla and Nealler 1978). At the time of
this writing, no additional information on the physical or chemical
characteristics of the tailings or effluent were available.
The last copper mine for which information is presently available is
the Repparfjord Mine in Norway (Figure 43), which produces 1,600 tons of
flotation tailings per day. The tailings are discharged into Repparfjord at
50 m (164 ft) depth via an outfall pipe (Down and Mill 1978). They contain
0.05 percent residual copper (Doughty 1975). No additional information on
the physical or chemical characteristics of the tailings are presently
available.
Iron Mines
The Ma On Shan Iron Mine has been disposing of iron ore tailings along
the eastern bank of Tide Cove, Tolo Harbour, Hong Kong since 1906 (Figure
44). Iron is extracted from the ore using a "wet magnetic separation
process" (Wong and Tarn 1977), and the tailings are deposited behind dams in
the nearshore area (Wong et al., 1978). Through time the tailings have
overflowed the dams and entered the nearshore marine environment.
Historically, tailings were first deposited in Region I, then Region III,
and finally Region II as shown in Figure 45. Data on grain size and
chemical composition of the tailings are given in Tables 46 and 47,
respectively.
The Kennedy Lake Iron Mine in British Columbia (Figure 46) disposed of
iron ore tailings into Toquart Bay until 1968, when the operation ceased.
Iron was separated from the ore by the wet magnetic separation process, and
tailings were transported to the beach via a pipeline (Levings 1975). No
additional information on the quantities or physical and chemical
characteristics of the tailings are presently available.
Lead-Zinc Mines
Detailed information is available for one lead-zinc mine which
discharges tailings into marine waters, the Greenex Mine in Greenland
(Figure 47). A marine discharge was also considered for the Nanisivik
Lead-Zinc Mine on Baffin Island, Canada, but this disposal option was
dropped prior to commencement of mining operations in 1976a. Since 1973,
a Letter from Dr. D.V. Ellis, University of Victoria, British Columbia
dated February 3, 1982. '
276
-------
El Salvador
% Copper tailing Domestic waste ,—._.
e v s-^f canal water canal
(a) Locations of the copper nine, city of
Chanaral, tailings canals, domestic wastewater
discharge, and bed of Rio Salado. (b) Shoreline
from Puerto pan de Azucar to Chanaral, Indicating
new and old tailing disposal sites.
REFERENCE: CastUla and Nealler, 1978.
Figure 42. Location of the El Salvador Copper Mine, Chile.
277
-------
ARCTIC OCEAN
Arctic circle 66.5'N -
USSR
100 200
J MILES
| 1 ] KILOMETERS
0 100 200
REFERENCE: Doughty, 1975.
Figure 43. Location of the Repparfjord Copper Mine in
northern Norway.
.278
-------
1 \ KILOMETERS
5 10
REFERENCE: Wong and Tarn, 1977.
Figure 44. Locations of the Ma On Shan tailing disposal area, Railway Beach, and
Long Harbour, Hong Kong.
-------
PIER
CRUSHING AND
SEPARATING PLANT
... MA ON SHAN
• . VILLAGE
0 500
I I I I I I METERS
(Mill YARDS
0 500
REFERENCE: Wong and Tarn. 1977.
Figure 45. Map of the Ma On Shan tailing disposal site,
Tolo Harbour, Hong Kong.
280
-------
TABLE 46. CUMULATIVE CURVE DERIVATIVES FOR THE ANALYSIS
OF SEDIMENT9 NEAR THE MA ON SHAN DISPOSAL AREA
Stations
Median Diameter
0 mm
Quartile
Deviation
Quartile
Skewness
Iron Ore Tailings
Zone I
Upper
Middle
Lower
Zone II
Upper
Middle
Lower
Zone III
Upper
Middle
Lower
+1.15
+1.27
+1.51
+2.28
+2.59
+2.43
+1.31
+1.02
+1.22
0.45
0.41
0.35
0.22
0.17
0.19
0.40
0.49
0.43
+1.28
+0.94
+1.06
+1.42
+1.48
+1.65
+1.05
+1.45
+1.19
-0.22
-0.20
-0.17
-0.38
-0.85
-0.78
-0.04
-0.23
+0.02
Railway Beach
Upper
Middle
Lower
-0.16
+0.29
+0.76
1.12
0.82
0.59
+0.88
+1.43
+1.57
+0.02
•+0.07
+0.32
Long Harbour
Upper
Middle
Lower
+0.13
+0.67
+0.83
0.91
0.63
0.56
+1.21
+1.26
+1.29
+0.17
+0.09
+0.02
The data are expressed as the means of triplicate samples,
from Table 3 of Wong et al. (1978).
The data are
281
-------
CD
TABLE 47. CHEMICAL CHARACTERISTICS OF TAILINGS AND SEDIMENTS FROM RAILWAY BEACH AND LONG HARBOUR3
Iron Ore Tailings ,
Zone 1 Zone II Zone III Railway Beach" Long Harbour
UML UML UML UML UML
pH 8.05 8.10 8.13 8.71 8.31 8.32 8.35 8.31 8.39 7.81 8.10 7.71 8.08 8.01 8.05
Organic carbon (%) 0.54 0.79 1.80 0.20 0.13 0.74 0.95 0.98 1.06 0.86 1.32 5.17 0.76 0.90 4.65
Total nitrogen (%) 0.09 0.10 0.17 0.09 0.09 0.16 0.10 0.12 0.18 0.13 0.16 0.20 0.21 0.25 0.26
Available
phosphate (ppra) 0.17 0.21 0.34 0.23 0.35 0.53 0.29 0.26 0.39 0.34 1.60 2.32 0.80 0.98 0.99
3 The data are expressed as the means of duplicate samples. The data are from Table 2 of Wong et al. (1978).
Abbreviations used: U = uppershore, M = middle shore, L = lower shore.
-------
• 49"00' N
VANCOUVER ISLAND
0 500
' ' ' ' I 'YARDS
I I I I I I METERS
0 500
STOCKPILE
KENNEDY LAKE
IRON MINES
N
/N
TOQUARTBAY
REFEREHCE: Levings. 1975.
Figure 46. Location of the Kennedy Lake Iron Mines on
Toquart Bay, British Columbia.
283
-------
00
-p.
REFERENCE: Anon, 1975.
Figure 47. Location of the Greenex Lead-Zinc Mine, Greenland.
-------
tailings from the Greenex Mine have been discharged into Qaumarujuk and
Agfardlikavsa Fjords at a depth of 25 m (82 ft) (Anon 1975). Approximately
1,400 tons of tailings are discharged into the fjords daily. Residual lead
and zinc constitute 0.4 percent and 0.1 percent of the tailings solids,
respectively (Anon 1975). Additional information on the physical and
chemical characteristics of the Greenex Mine wastes are not presently
available.
Nickel Processing
The Yabulu nickel refinery is located on Halifax Bay approximately 24
km (15 mi) northwest of Townsville, Queensland (Figure 48). The refinery
treats about 2,200,000 tonne/yr of lateritic ore which is delivered by train
from the Greenvale Mine, about 225 km (140 mi) west of the refinery (Reid
1980).
Nickel is recovered through an hydrometa11urgica 1 process
(ammonia/ammonium carbonate leach) following grinding and reduction
roasting. The waste produced by this process is an approximately 50 percent
slurry of tailings particles of which 60 percent are less than 44 urn in
diameter. Tailings solids account for 98.5 percent of the ore processed
(Reid 1980).
Tailings are discharged to a settling pond and approximately 17,500
m3/day (4.6 MGD) of decanted liquid is discharged to Halifax Bay. Effluent
is discharged through a 2,000 m (6,600 ft) outfall pipe which terminates in
a three-port diffuser (Reid 1980).
No data are available on the chemical composition of solids content of
the effluent, however, Reid (1980) has presented the effluent limitations
established by the Water Quality Council as shown in Table 48.
Bauxite Mines
Approximately five million tons of bauxite ore are processed yearly
(Lillehagen 1980) at the refinery on the Gove Peninsula in Northern
Australia (Figure 49).
The red mud slurry has a pH of 10.2 to 12.4 and a "silt-like texture,"
since 95 percent of the solids have a diameter of less than 0.06 mm (Baseden
1976). The solids are primarily composed of iron, aluminum, silicon, and
titanium, and oxides of sodium and calcium. Traces of zinc (3 ppm), copper
(3 ppm), and manganese (11 ppm) are also present (Baseden 1976). The
alkaline supernatant liquor is neturalized with sea water prior to leaving
the second of two sluice boxes and entering the estuary. Neutralization
causes the complete precipitation of the carbonate and hydroxide ions
through the formation of calcium and magnesium compounds (i.e., hydroxides
and carbonates). The supernatant liquor discharged to the estuary contains
less than 0.5 ppm of dissolved zinc, copper, or manganese (Baseden 1976).
285
-------
146.30
CD
cr>
19.00
19.15
CORDELIA
ROCKS
146.45
UEENSLAND
NICKEL
PTY. LTD.
N
NAUTICAL MILES
REFERENCE: Reid 1980
Figure 48. Location of Yabulu Nickel Refinery Outfall.
-------
TABLE 48. YABULU REFINERY EFFLUENT LIMITATIONS FOR DISCHARGE TO
HALIFAX BAY, AUSTRALIA
Maximum Effluent
Parameter in Effluent
Flow, m3/day 17,500
pH, range in units 6.5 to 8.5
Total ammonia-N, mg/1 500
Free ammonia-N, mg/1 100
Total nickel, mg/1 1
Total cobalt, mg/1 0.1
Total iron, mg/1 5
Total manganese, mg/1 5
Maximum Allowed
after Dilution3
Total ammonia-N, mg/1 1
Total nickel 0.05
Total cobalt 0.01
Biological Effects
The discharge of effluent shall have not deleterious effect on the
marine environment.
a Within a mixing zone of 400 m (1,300 ft) radius.
Reference: Reid 1980.
287
-------
REFERENCE: Baseden, 1976.
Figure 49. Locations of the bauxite refinery and red mud
settling ponds at Gove, Australia.
288
-------
Potash Mines
The Cleveland Potash Mine in Boulby, Yorkshire, England disposes of
about 240 tons per day of insoluble tailings to the marine environment
(Figure 50). The tailings are carried offshore via a submarine outfall pipe
which is located within a submarine tunnel (Figure 51). The tunnel and
discharge pipe extend about 1.8 km (1.1 mi) offshore (Cleasby et al., 1975).
Intake pipes located in the tunnel provide sea water for mixing a weak
tailings slurry which is discharged through nozzles at a depth of 25 m (84
ft).
The primary constituent of the tailings is halite. Sylvite, anhydrite,
calcium and magnesium carbonates, quartz, clay minerals, pyrite, and
hematite are also present in small quantities (Cleasby et al., 1975). The
halite, sylvite, and anhydrite are soluble in seawater, and dissolve in the
outfall pipe or shortly after discharge. The remaining 6 percent of the
tailings which are insoluble are dispersed by strong currents at the
discharge site (Cleasby et al., 1975).
DREDGED MATERIAL
Dredged material consists of a wide range of natural and anthropogenic
materials. In terms of textures, dredged materials can range from nearly
all clay-size particles to clean sands and gravels. The size
characteristics of the sediments generally reflect the energy level of the
environment from which they are dredged. Sediments in coastal and inland
waters subject to high water velocities or wave energy contain only small
fractions of silt- and clay-size particles because of the lack of
opportunity to settle. In quiescent waters, fine-grained particles can
settle. If a source of silt and clay exists, sediments will likewise be
predominantly fine grained.
In 1979, the New York District, Corps of Engineers reported the
percentage of sand, silt, and clay for 25 dredging projects which involved
ocean disposal of the dredged material (COE 1980). These projects involved
3.1 million m^ (4.1 million yd^) or 31 percent of all dredged material
dumped in the U.S. waters of the Atlantic Ocean in 1979. The means of the
reported grain-size distributions were 34 percent sand, 43 percent silt, and
23 percent clay.
The chemical composition of dredged material also covers a wide range,
again generally related to the energy level of the environment from which
the sediments are dredged. Metals, present as contaminants, are generally
transported to the sediments with settling organic and inorganic solids.
Because surface adsorption is the common mechanism for bonding of the metal
ions to particles, the smaller particles which present the greatest surface
area per unit volume are the most efficient transporting medium. For this
reason, sediments with high percentages of organic materials and clay-size
particles generally contain higher concentrations of pollutants.
The U.S. Army Corps of Engineers prepares reports of all ocean dumping
of dredged materials. Many of these reports, required by the London Dumping
289
-------
no
in
O
Narllepool
Redcar
TEESSIDE
TAILINGS OUTFALL AND
SEAWATER INTAKE
TUNNEL
CLEVELAND POTASH Whllby
MINING LEASE AREA
I MILES
(KILOMETERS
-------
DISTANCE FROM SHAFT
t
0
SHAFT
1000
i
2000
3000
4000
5000
, FEET
6000
FEET
BELOW
COLLAR
PUMP
CHAMBER
ro
\ n I2—,,,,,
V INTAKES
SEA LEVEL 1 2
'"" '"" """iiiiiiiuiiiii uiiiiiiimi -
OUTFALLS
0
100
200
300
400
500
600
REFERENCE: Cleasby et al., 1975.
Figure 51. Diagram of submarine tunnel used for the discharge of potash mine
tailings by Cleveland Potash, Ltd., Yorkshire, England.
-------
Convention, include information on the dredged sediments chemical
composition. All results of bulk analyses performed on sediments dumped in
the ocean during 1978 and 1979 are summarized in Table 49.
Table 50 reports the results of elutriate tests performed on some of
the same sediments. The elutriate test is a leaching test designed to
simulate the characteristics of the material as it is discharged from a
hydraulic dredge. The test is performed by mixing one volume of sediment to
be dredged to four volumes of water from the dredge or disposal site. The
mixture is thoroughly mixed and allowed to settle. The liquid fraction of
the sample is then analyzed. The elutriate test thus provides an estimate
of the metals discharged in the dissolved state. The standard analytical
methods used does not, however, distinguish between truly ionic and
non-ionic species.
DRILLING MUDS AND CUTTINGS
The drilling of offshore oil and gas wells produces waste rock
(cuttings) from the hole and drilling fluids which are discharged to the
marine environment. Their physical and chemical characteristics vary
widely. The composition of the cuttings depends upon the rock and fluids
being encountered by the drill bit. The introduction of drilling muds to
the hole achieves many purposes but mainly serves to reduce friction, remove
solids, and maintain down-hole pressure.
Drilling mud is, in general, composed of 80 to 90 percent barite
(BaS04), 10 to 20 percent clay, and small quantities of special purpose
additives (Kali! 1980). The American Petroleum Institute (1978) has
compiled a list of drilling fluid additives, of which there are 43 generic
varieties of additives and at least 231 proprietary formulations. At any
given well, depth, and time, a dozen or more additives may be used to
control downhole conditions (API 1978). Petrazzulo (1981) has provided a
detailed review of drilling fluids and their usage.
Analyses of used drilling muds and cuttings have been reported by Liss,
et al. (1980), Ayers, et al. (1980), and Sauers (1981). The range of metals
concentrations in the whole muds are shown in Table 51.
Table 51 also presents the results of analyses of the "mud aqueous
fraction" of four used drilling fluids performed by McCulloch, et
al. (1980). The mud aqueous fraction was composed of one part drilling mud
mixed with nine parts artificial seawater. The mixture was stirred
thoroughly and allowed to settle for 20 hours. The liquid fraction was then
analyzed. These results provide an indication of the concentration of
dissolved metals associated with the discharge. As with the dredged
material, the actual amount of metal in true ionic form is not known.
292
-------
TABLE 49. METALS CONCENTRATIONS IN DREDGED MATERIAL
SOLIDS DUMPED AT SEA - 1978 AND 1979
As
Be
Cd
Cr
Cu
Fe
Hg
Mn
Ni
Pb
V
Zn
Percent
Volatile
Solids
Number of
Observations
52
23
57
52
55
39
61
7
52
61
20
61
27
Average
Concentrations
mg/kg
4.0
0.89
1.2
33.0
30.4
8,417
0.3
316
15.0
29.6
10.6
68.8
7.2
Range
0.03 to 23
0.25 to 3
0.02 to 7
0.25 to 190
0.23 to 449
100 to 95,000
0.01 to 2.7
188 to 570
1.2 to 82
0.25 to 600
0.25 to 82.2
0.25 to 1,246
0.4 to 18
293
-------
TABLE 50. ELUTRIATE ANALYSIS OF DREDGED MATERIAL
DUMPED AT SEA - 1978 AND 1979
As
Cd
Cr
Cu
Fe
Hg
Mn
N1
Pb
Zn
Number of
Observations
25
29
23
24
17
28
9
23
24
29
Average
Concentrations
ug/1
4.9
1.6
4.8
2.7
17.6
0.3
1,038
6.8
6.8
32.5
Range
1 to 24
0.2 to 2.9
0.5 to 30
1 to 8
2.5 to 33
0.01 to 1.8
30 to 2,300
2 to 21
0.9 to 12.5
10 to 70
294
-------
TABLE 51. OBSERVED COMPOSITION OF USED DRILLING MUDS AND CUTTINGS
Whole Muda Mud Aqueous Fraction0
Concentration Range, mg/kg Nb Concentration Range, ug/1
As
Ba
Cd
Cr
Cu
Pb
Hg
Ni
9
V
Zn
<1.0 to 3
2,800 to 202,000
<1.0 to <2.0
2 to 1,007
2 to 28
<1 to 24
<1 to 2.2
1 to 21
6 to 35
12 to 236
6
11
9 60 to 80
12 <100 to 1,080
9
9 <500
9
9
9
9 60 to 230
Nb
4
4
4
4
a Data from Liss, et al. (1980), Ayers, et al. (1980), and Sauers (1981).
b N = number of analyses.
c McCulloch et al. (1980).
295
-------
APPENDIX D
DETAILED DESCRIPTION OF THE OCEANOGRAPHIC CHARACTERISTICS FOR
REPRESENTATIVE DISPOSAL AREAS
This appendix provides a detailed description of the oceanographic
characteristics for the representative disposal areas previously identified
in Chapter 6 of this report. In that chapter the information presented
summarized the physical and biological oceanographic conditions at each
area. The information presented in this appendix is the basis from which
that summary is extracted.
In general, the disposal areas represent typical nearshore, midshelf,
and deep water areas within each primary region (with the exception of
Hawaii for which only one area is identified). For each region, general
physiography, bathymetry and circulation patterns are presented to provide a
regional setting. Generalized profiles of temperature, salinity, density,
dissolved oxygen, and currents are provided for the representative areas
within each region. In addition, biological oceanographic descriptions of
each region with particular emphasis on the specific areas are provided.
This is followed by a discussion of important fishing locations.
WESTERN GULF OF MEXICO
Physical Characteristics
The Gulf of Mexico is a relatively shallow (3,600 m maximum depth)
semi-enclosed water body connected to the Atlantic Ocean by the Florida
Straits and the Yucatan Channel (Figure 52). Basin physiographic features
(Figure 53) include the shelves of East Mexico, Texas, Louisiana, and
Western Florida; an upper continental slope; the Mississippi Cove; the
Campeche, Sigsbee, and West Florida escarpments; the continental rise; the
abyssal plain and the Sigsbee Knolls. The Gulf does not contain any major
ridge or trench systems but does present a variety of geological structures
including salt domes, mud diapirs, escarpments, submarine canyons, abyssal
fans, channels and terraces, and coral reefs.
Bathymetry--
The continental shelf along the northwestern Gulf of Mexico between the
Mexican border and the Mississippi Delta is a gently sloping, smooth,
sediment-covered plain interrupted by occasional hills or banks (Curray
1960). The shelf width ranges from approximately 90 km (56 mi) near the Rio
Grande in Texas to about 200 km (124 mi) south of the Texas-Louisiana
boundary.
296
-------
30°
25°
20°
200m.
1000 m._
FLORIDA STRAITS
95°
90°
85°
80°
REFERENCE: Nowlin 1972
Figure 52. Bathymetry of Gulf of Mexico.
297
-------
• 1 op
UPPER CONTINENTAL SLOPE
Sigsbee Knolls
ABYSSAL PLAIN
25
20° *•
REFERENCE: after Ewing et al., 1958.
Figure 53. Physiographic subdivisions of the Gulf of Mexico
and selected stations of Hidalgo 62-H-3 cruise of
March 22-27, 1962.
298
-------
Further east, approaching the Mississippi Delta, the shelf narrows
considerably, becoming non-existent in some places. The outer shelf edge is
relatively well defined in many areas by a number of elongated ridges and
escarpments at an average depth of approximately 120 m. In some areas,
however, the shelf/slope transition is smooth, gradual, and rounded in
nature. Western Gulf shelf gradients along transects A and B (Figures 52
and 54) are 0.08° or 1.4 m/km and 0.03° or 0.59 m/km, respectively.
A series of widely spaced shelf banks (e.g., the West Flower Garden)
rise above relatively smooth bottom reef structures predominantly at depths
of 16, 60, and 90 m. Those with relief greater than 4-6 m are believed to
have been caused by underlying salt domes, while others with less relief are
considered remnants of earlier shoreline deposits. Recent (Holocene)
sediments on the shelf are generally non-calcareous silty-clays,
particularly near the Mississippi Delta and off the central Texas coast.
However, in offshore areas between east-central Texas and western Louisiana,
the surface lithology shows great variation, being mostly sandy and
containing much shell material (Shepard 1963).
The upper continental slope extends in a west-southwest direction, with
little indication of widening due to Mississippi Delta sedimentation. The
slope extends approximately 240 km beyond the shelf off the Louisiana-Texas
boundary and is extremely irregular in relief due to the intrusive nature of
the underlying salt deposits, erosion associated with lowered sea levels in
the past, and probably some submarine slumping. The average upper slope
gradient between depths of 180 and 360 m is 1.1° or 18.9 m/km.
The continental slope ends at between 1,800 and 2,000 m (5,900 and
6,560 ft) at the Sigsbee Escarpment which drops another 1,000 m (3,280 ft).
Beyond the escarpment is the continental rise leading to the abyssal plain
which reaches depths of 3,600 m (11,810 ft). The plain is a remarkably
flat, oval shaped basin having bottom gradients o.f only 1/8000 (Ewing et
al., 1962). Although the eastern portion of the abyssal plain is known to
be partially covered by Mississippi Cove sediments (reddish-brown
foraminiferal lutite overlying beds of grey silty clay), less is known
regarding the characteristics of sediments in the extreme western portion of
the plain. The clustered Sigsbee Knolls, which rise 100-200 m (328-656 ft)
above the plain, have sediments consisting of foraminiferal oozes due to
deposition of planktonic debris.
Circulation Patterns--
The large scale circulation pattern in the Gulf of Mexico is dominated
by two current systems; the strong well-defined clockwise Loop Current in
the east, and an elongated less permanent clockwise circulation cell located
over the deeper areas of the central and western Gulf. The Loop Current
enters the eastern Gulf through the Yucatan Straits, exiting through the
Straits of Florida (Leipper 1970; Maul 1977). The horizontal distribution
of temperature in the main thermocline is well correlated with the dynamic
topography of the sea surface (Now!in 1972). Loop current seasonality was
examined by Leipper (1970) on the basis of temperature data, resulting in
definition of a "spring intrusion" to describe growth of the loop into the
299
-------
, PADRE ISLAND
X
-------
Gulf, and "fall spreading" to describe the subsequent westward movement of
the loop or of a detached eddy. The velocity in the core of such a detached
eddy was observed in 1965 to be 113 cm/sec, which was comparable to that in
the East Gulf Loop Current itself. One month later, after passage of a
hurricane, the eddy was considerably modified in shape, and core velocities
had decreased to 73 cm/sec (Leipper et al., 1972).
An analysis of 1958-1964 data indicates that the western Gulf is
dominated, in the wintertime at least, by a weak clockwise gyre, apparently
driven in part by separated portions of the Loop Current and partly by
surface winds. The gyre, whose major axis is oriented in a northeast-
southwest direction, consists of a broad, rather weak southwestward flow on
the southern flank, and a somewhat more narrow and stronger flow in the deep
water portion of the northern Gulf. Velocities in the core of the
northeastward-flowing current have been computed to be some 50 cm/sec
(Figure 55), whereas downstream core flows appear to decrease to
approximately 30 cm/sec.
In addition to the clockwise western Gulf gyre, there may be a narrow
westward counterclockwise flow just above the continental slope, separated
from the gyre by a strong shear zone. A north-flowing western boundary
current may also exist as noted by Sturges and Blaha (1976), evidenced in
modeling experiments (Ichiye et al., 1978), and shown by the trajectory of
tracers released off the coast of Mexico (Vasquez 1975).
Isotherm depths reported by Sturges and Morton (1981) suggest that the
flow approaches the coast at 22-23° N and remains near the western boundary
all the way to the continental shelf in the north. Winter satellite
photographs indicate departure of this flow from the coast at approximately
28° N near the mouth of the Rio Grande River.
Several hypotheses have been offered for the irregularity and driving
mechanism of the clockwise gyre in the western Gulf. Some researchers
suggest that the gyre is the result of forcing by the wind stress curl
rather than by pinched-off eddies, which would explain stronger winter and
summer currents in phase with wind forcing. Others feel the gyre is always
present as in the Atlantic and Pacific basins. Maul (1977) in studying the
annual Loop Current penetration cycle confirmed Leipper's (1970) proposition
that there is an annual cycle of growth and decay, but that year-to-year
variability in the pattern is significant. An eddy separation from the Loop
Current appears to have occurred each year during the 1972 to 1976 period
examined. Molinari et al. (1978) confirmed the Leipper cycle on the basis
of computed monthly sea surface dynamic topographies. A permanent
counterclockwise flow on the Texas Shelf was found to join the eastward
transport of the northern limb of the clockwise gyre in the western Gulf.
Behringer et al. (1977) found that Loop Current penetration into the Gulf
increases during the winter and spring periods, reaching a maximum in early
summer. At that time, a large eddy separates from the loop. Deviations
from this pattern were also noted, however, (i.e., year-round persistence of
the clockwise gyre, and strongest periods during summer and winter).
Molinari (1980) has concluded that the typical Loop Current cycle of spring
intrusion, summer eddy breakoff and fall spreading may not be typical, and
that such events may occur during any season.
301
-------
VELOCITY DIAGRAM
FOR 25° N. LATITUDE
Direction of Flow
REFERENCE: Nowlin, 1972.
Figure 55.
Dynamic topography of sea surface relative to the
1,000-db surface, Hidalgo 62-H-3, x's indicate
some extrapolation. Contour interval, 0.05
dynamic meters.
302
-------
The western Gulf of Mexico is a difficult area to describe, owing to
the paucity of observations and to the complexity of the pertinent dynamics.
The presence of two important driving mechanisms seems apparent; the eddies
propagating to the west, and the wind field. Elliot (1979) concludes that
the eddies take approximately a year to drift from their eastern formation
region to the western side of the Gulf. He also feels that the western gyre
is half driven by the introduction of one new large eddy per year, and half
driven by the wind stress. However, what happens when an eddy moves into
the region, its path and decay characteristics, are not yet well known.
Characteristics of Representative Areas
Two general locations are considered as representative of potential
nodule processing waste disposal sites; a midshelf site and a deepwater
site. In addition, conditions at an upper-slope site are also described
because of the site's historical use for chemical waste disposal (Atlas et
a!., 1980). Shallow nearshore waters and a gentle bottom slope effectively
preclude disposal of nodule processing wastes through a nearshore outfall
pipe.
Oceanographic data from Texas ASM western Gulf synoptic oceanographic
surveys in February and March, 1962, serve to define selected parameters in
each area. Stations 120, 122, and 92 shown in Figure 53 are considered
representative of mid-shelf, upper-slope, and deep basin areas,
respectively. In synthesizing the physical oceanographic nature of each
area, many technical documents were reviewed in addition to the Texas A & M
transect data (Table 52). Nevertheless, the data set available for
compiling general area characteristics was found to be limited (e.g.,
seasonally or for a particular parameter) not only for the Gulf of Mexico
areas, but for west coast and Hawaiian areas as well.
Mid-Shelf«
The temperature, salinity, density and dissolved oxygen characteristics
of a mid-shelf disposal site in the north-western Gulf of Mexico are
presented in Figure 56. Nearshore surface salinities are typically low due
to intrusion of freshwater from continental drainage (Nowlin 1972).
Salinity increases with depth and with distance offshore. Due to
significant mixing, temperatures are relatively uniform with depth. This
temperature-salinity combination results in a typical March density gradient
of 1.0 sigma-t units in the upper 30 m. Dissolved oxygen levels are
relatively uniform with depth, decreasing from 6.5 to 5.8 ml/1.
Current measurements on the shelf indicate that they are typically
aligned alongshore, are highly seasonal, and exhibit layering of contrasting
flow in late spring and during summer (Armstrong 1980). Mean surface
currents are downcoast to the southwest throughout the year, with an onshore
component in summer. Mid-depth to bottom flows are directed upcoast and
offshore (east and southeast, respectively) from May to August, and
downcoast the remainder of the year. Deeper eastward currents do occur
during some winter periods. Mean current speeds decrease with depth, being
303
-------
TABLE 52. REFERENCES CONSULTED IN SYNTHESIZING THE PHYSICAL
OCEANOGRAPHIC CHARACTERISTICS OF WESTERN
GULF OF MEXICO DISPOSAL AREAS
Anderson et al., 1979
Atlas et al., 1980
Atlas et al., 1981
Behringer et al., 1977
Curray 1960
Dietrich 1939
Ewing et al., 1962
Ichiye et al., 1978
Ichiye et al., 1981
Leipper 1970
Leipper et al., 1972
Maul 1977
McLellan and Nowlin 1963
Meyer and Warsh 1981
Molinari 1980
Mungall and Home 1978
Nowlin 1971
Nowlin 1972
Okubo and Ebbesmeyer 1976
Shepard 1963
Sturges and Blaha 1976
Sturges and Horton 1981
U.S. Naval Oceanographic Office 1972
Vasquez 1975
304
-------
SALINITY, %o
35 36
10
E 20
a.
ui
Q
30
40
TEMPERATURE, C°
18 19
Q.
Ill
Q
DENSITY, Qt
25 26
DISSOLVED OXYGEN, mg/l
5 6
REFERENCE: Now!in 1972
Figure 56. Characteristics of a Western Gulf of Mexico
mid-shelf disposal site.
305
-------
approximately 15 cm/sec near the surface and decreasing to 10 cm/sec near
the bottom. Seasonally, speeds are lowest in summer and highest in the fall
and spring. Flow variability is principally due to wind shifts and tidal
currents.
Upper-Slope--
Further offshore, the salinity is relatively constant at 35.9 ppt in
the upper 50 m (164 ft), increasing somewhat between 100 and^ZOO m to 36.1
ppt, and thereafter decreasing gradually with depth to approximately 35 ppt
(Figure 57). The March temperature profile indicates a gradual reduction in
temperature from approximately 20° C near the surface to 4° C at 1,000 m
(3,280 ft). The resultant density profile (Figure 58) consists of a small
positive density gradient to the 50 m (164 ft) point, a sharp density
increase between 50 and 120 m (164 to 492 ft), tapering off to a relatively
small increase with depth thereafter. Surface dissolved oxygen
concentrations of 6.5 to 7.0 mg/1 decrease to a minimum of approximately 3.5
mg/1 at between 250 and 400 m (820 and 1,312 ft), and increase to 5.0 mg/1
at 1,000 m (3,281 ft). Geostrophic flow is predicted to generally be
eastward, varying from 25 cm/sec near the surface to less than 5 cm/sec
below 350 m (1,148 ft), as shown in Figure 59. At the industrial-chemical
waste disposal site A (water depths of 900-1,400 m), absolute near-surface
currents on the order of 26 cm/sec or less have been measured (Mungall and
Home 1978).
Deep Basin—
Beyond the slope, over the abyssal plain, surface water salinities
commence at 36.1 ppt, increase slightly to a maximum of 36.35 ppt at 125 m
(410 ft) and decrease sharply thereafter, reaching a minimum of 34.89 ppt at
580 m (1,902 ft). At greater depths, the salinity asymptotically approaches
34.97 ppt (Figure 60). Temperature decreases rather slowly from 22.3° C at
the surface to 20.5° C at 125 m (410 ft). At this depth however, a
pronounced gradient occurs, with temperature decreasing 15° C in the next
800m (2,624 ft). Beyond this depth the temperature remains relatively
constant at 4.2° C. The associated density profile (Figure 61) indicates a
uniform surface density of 25 sigma-t units in the upper mixed layer [in
this case down to 25 m (82 ft)]. A relatively sharp pycnocline occurs
beyond this point, with sigma-t values increasing another 2.75 units by the
1,000 m (3,281 ft) depth. Thereafter, the density remains relatively
constant at 27.75 sigma-t units.
Dissolved oxygen concentrations of 6.1-6.9 mg/1 in the upper 100 m (328
ft) decrease sharply to a characteristic minimum of 3.83 mg/1 at
approximately 250 m (820 ft). Beyond this depth, dissolved oxygen
concentration increases, at first relatively slowly to 4.9 mg/1 at 775m
(2,542 ft), then quickly to 5.91 at 70 m (3,182 ft), and thereafter again
slowly to a maximum value of 4.83 mg/1 at 2,920 m (9,579 ft).
Calculated geostrophic flows for a deep-basin area (Figure 62) indicate
westward surface currents of up to 35 cm/sec, decreasing to no current at
approximately 350 m (1,148 ft). Beyond this depth, very low flows are
306
-------
34 35
100 -
200 -
300 -
400 -
_ 500 -
2
Q.
0)
600 -
700 -
800 -
900 -
1000 -
1143
100 -
200 -
300 -
400 -
5 500 -
Q,
05
Q
600 H
700 i
800 -
900 -
1000 -
1143
Salinity, %
Temperature, C°
DATA FROM: National Oceanic Data Center
Figure 57. Temperature and salinity profiles characteristic of
the western Gulf of Mexico upper slope, Hidalgo
Cruise 62-H-3, March, 1972.
307
-------
27 28
100 -
200 -
300 -
400 -
^ 500 -
Q.
CD
0
600 -
700 -
800 -
900 -
1000 -
1143
100 -
200 -
300 -
400 -
^ 500 -
O.
0)
Q 600 -I
700 -
800 -
900 -
1000 -
1143
Density, (J,
Dissolved Oxygen,mg/l
DATA FROM: National Oceanic Data Center
Figure 58. Density and dissolved oxygen profiles characteristic
of the western Gulf of Mexico upper slope, Hidalgo
Cruise 62-H-3, March, 1972.
308
-------
Current (cm/sec)
11 13 15 17 19 21 23 25
EAST
900-
1000-1
DATA FROM: National Oceanic Data Center
Figure 59. Geostrophic flow profile for an upper-slope area
between Stations 122 and 123, Hidalgo Cruise
62-H-3, March, 1972.
309
-------
34
500-
1000-
150H
2000-
2500-
3000
35
I
36
Salinity, %<,
0 5 10 15 20 25
i i | i .
500-
1000-
1500-
UJ
Q
2000-
2500-
3000
Temperature, °C
DATA FROM: National Oceanic Data Center
Figure 60. Salinity and temperature profiles for a deepwater
area in the northwestern Gulf of Mexico,
Hidalgo Cruise 62-H-3, March, 1972.
310
-------
25
500-
1000
~ 1500-
0)
Q
2000-
2500-
3000-
26
I
27
I
28
Density,
500-
1000 -
£ 1500 -J
Q.
a
2000-
2500-
3000-
Dissolved Oxygen, mg/l
DATA FROM: National Oceanic Data Center
Figure 61. Density and dissolved oxygen profiles for a deep-basin area in the
northwestern Gulf of Mexico, Hidalgo Cruise 62-H-3, March, 1972.
-------
35
Current (cm/sec)
25 20 15 10
900
1000
DATA FROM: National Oceanic Data Center
Figure 62. Geostrophic flow profile for a deep-basin area
between Stations 91 and 92, Hidalgo Cruise
62-H-3, March, 1972.
312
-------
indicated, eastward at up to 1.2 cm/sec down to 550 m (1,804 ft), and
thereafter again westward at greater depths, but at less than 1 cm/sec.
Biological Characteristics
Open Ocean Environments of the Gulf of Mexico--
In open ocean environments of the Gulf of Mexico, far removed from
effects of proximity to land, virtually all primary production is performed
by phytoplankton. Due to its dependence on sunlight, phytoplankton
production is limited to the upper (< 100 m usually) sunlit layers of the
gulf. All other life in these environments is dependent on the fixation of
carbon by phytoplankton, and hence production by the phytoplankton is
essential to all higher trophic levels. Phytoplankton production in the
Gulf of Mexico is primarily limited by the availability of nutrients
(especially nitrogen as nitrate or ammonium), which are typically in very
low concentrations in the upper 100 m. Nutrients are supplied to the
phytoplankton either by upward transport from deeper, nutrient-rich water,
or by excretion of animal wastes. As a consequence of the vertical
stratification of the water column, the supply of nutrients from deeper
waters is slow. Regeneration of nutrients by animals is important, but due
to losses from the upper layers (e.g., the sinking of fecal pellets), it
cannot completely supply the required nutrients. Since nutrients are in
short supply, jDhytoplankton production in the western Gulf of Mexico is low
[290 mg C m'^day'1; El-Sayed and Turner (1974)], and consequently,
production at all higher trophic levels is also low, relative to coastal and
nearshore areas.
One result of the supply of nutrients from deeper waters is that
phytoplankton biomass is often greater deep in the euphotic zone than at
shallower depths. Hobson and Lorenzen (1972) reported, for instance, that a
subsurface maximum in chlorophyll a_ concentration (a commonly-used measure
of phytoplankton standing stock) was typically found at depths between 50
and 90 m in the Gulf of Mexico. During times when the subsurface
chlorophyll maximum was well developed, the top of the pycnocline was often
at less than 100 m depth. When the top of the pycnocline was depressed
below about 100 m, no subsurface chlorophyll maximum was observed. Hobson
and Lorenzen (1972) suggest that these results indicate that the depth of
the chlorophyll maximum is influenced by the depth of the pycnocline, and
that this association is probably caused by the distribution of nutrients
near pycnoclines. This is supported by the data of El-Sayed and Turner
(1974), who found that at more than 90 percent of the stations occupied in
the Gulf of Mexico and the Caribbean, maximum chlorophyll £ concentrations
coincided with the depth of the nitrate nutricline. The depths of
development of the chlorophyll maximum do not appear to be related to
subsurface light intensities (Hobson and Lorenzen 1972).
Hobson and Lorenzen (1972) reported that the phytoplankton in the Gulf
of Mexico was dominated numerically by coccolithophores and diatoms, and
that numbers of cells decreased with depth even in the presence of
subsurface chlorophyll maxima. Thus, it is likely that the cells within
these maxima have increased their chlorophyll content, perhaps as a
313
-------
mechanism of adapting to the lower light intensities. Other authors (e.g.,
Hulburt and Corwin 1972) have also noted the dominance of the Gulf of Mexico
phytoplankton by coccol ithophores, notably Coccolithus huxleyi. The fact
that phytoplankton of the open Gulf of Mexico were predominantly small was
verified by El-Sayed and Turner (1974), who reported that nanoplankton
(cells < 20 urn in diameter) contributed 83 percent of the total chlorophyll
and 84 percent of the primary productivity in these waters. Hulburt and
Corwin (1972) noted, however, that phytoplankton were more abundant over the
continental shelves of the Gulf, and that diatoms were the dominant
phytoplankton near shore. They suggested that the nutrient-poor water
offshore "can support only the coccolithophorid type of flora." Diatoms are
also the dominant phytoplankton near the Mississippi River delta (Simmons
and Thomas 1962).
Oceanic phytoplankton are primarily consumed by zooplankton, many of
which filter these small cells from the seawater. Since body-size of the
grazer is often smaller when the food is predominantly small, oceanic
zooplankton are typically small relative to those in coastal and nearshore
areas. This is especially true in the Gulf of Mexico, where, as indicated
above, small coccol ithophores are the dominant phytoplankton. Iverson and
Hopkins (1981) reported, for instance, that microzooplankton, collected in
the central Gulf of Mexico by filtering the contents of water bottles
through a 30-um gauze, averaged 10 times the number and one-third the
biomass of the larger zooplankton sampled with a 162-um net. Near the
surface, small calanoid copepods predominate, while at intermediate depths,
larger calanoid copepods and euphausiids are abundant (Iverson and Hopkins
1981). While many zooplankton species inhabit the euphotic zone, others
perform die! vertical migrations which bring them into the euphotic zone
only at night. Iverson and Hopkins (1981) reported, for instance, that
increases in zooplankton biomass in the upper 50 m at night and in the
300-600 m zone in the day were likely the result of such migrations.
Zooplankton occur at all depths throughout the water column in the Gulf of
Mexico, but those occurring below about 200 m are almost exclusively
carnivores and/or detritivores.
All animals larger than zooplankton which inhabit the water column are
classified as nekton. This group includes not only fishes, but squid,
shrimp, whales, dolphins, etc. Common fishes occurring near the surface in
Gulf of Mexico waters include flying fishes, white (Tetrapturus albidus) and
blue (Makaira nigricans) marl ins, dolphins (Coryphaena hippur'us), sail fish
(Istiophorus platypterus), spearfish (Tetrapturus pfluegeri), and yellowfin
(ThunnusTTFacares) and bluefin (T. thynnus] tunaJI Marine mammals of the
Gulf of Mexico include various whale and dolphin species. The larger nekton
species are generally strong swimmers which range over large areas of the
oceans and are not restricted to a single geographic area. Because primary
production is low in the open waters of the Gulf of Mexico, and because
these larger species of nekton are a number of trophic levels removed from
the primary producers, they are quite rare considering the total expanse of
the Gulf of Mexico. Nevertheless, certain species (e.g., tunas) are known
to school, and consequently they may be abundant in a given area for a short
period of time.
314
-------
Many small nektonic species in the Gulf of Mexico inhabit mesopelagic
depths (100-1,000 m), and many of these perform die! vertical migrations
into the epipelagic zone (< 100 m) (cf. Hopkins and Baird 1975, 1977).
While these species are widespread, individuals of these species are not as
wide-ranging as those of the larger, epipelagic species.
With the notable exception of flying fishes, which attach their eggs to
floating objects, most pelagic fish species lay and fertilize their eggs in
the sea itself. The eggs and larvae, collectively referred to as
ichthyoplankton, are carried about by the currents. The larvae are
typically very small, and dependent on plankton for food.
Benthic animals, including both organisms living in and on the sea
floor and demersal organisms swimming just above the sea floor, are entirely
dependent on the production of organic matter in the overlying waters.
Organic matter is transported to the benthos in the deep Gulf of Mexico by
sinking carcasses, fecal material, exoskeletons, and detritus, and by the
vertical migrations of some nektonic species. Since the supply of organic
matter is inversely related to the distance from the surface, and since
primary production in the Gulf of Mexico is low, deep benthic life there is
sparse by comparison to benthic communities in shallow, nearshore areas
(Rowe and Menzel 1971). Rowe and Menzel (1971) found that the infaunal
biomass (expressed in terms of wet weight, dry weight, animal numbers, and
organic carbon) in the Gulf of Mexico decreased exponentially with
increasing depth. Animal abundance and biomass are quite low on the Sigsbee
Abyssal Plain, about one-tenth the values observed at comparable depths on
the Atlantic Continental rise (Thistle and Lewis 1981). The Sigsbee Abyssal
Plain, with depths in excess of 3,700 m, has been formed with sediments from
the Mississippi River. During the last glacial period (Wisconsin stage),
sediment accumulated on the plain at the rate of about 60 cm/1,000 yr. In
the past 10,000 yr (since the end of the last glacial period) sediment has
accumulated more slowly (about 8 cm/1,000 yr) (Gross.1977).
Thistle and Lewis (1981) indicate that the quantitative structure,
energetics, and physical and biological control mechanisms of benthic
communities in the deep Gulf of Mexico are largely unknown. It seems
likely, however, that the benthic organisms in the deep Gulf of Mexico are
similar to those in the other deep oceans of the world. Hence, these
organisms are likely to be either large, mobile scavengers able to locate
and utilize large organic "windfalls" such as carcasses, or very small (less
than a few millimeters in length) and not very mobile organisms living on or
in the sediments.
Outer Continental Shelf Environments of the Western Gulf of Mexico--
The productivity of the nearshore waters of the western Gulf of Mexico
is influenced by the discharge of water both from the Mississippi River and
from the Texas rivers. Near the mouth of the Mississippi, phytoplankton
photosynthesis may be depressed by high turbidity, but at greater distances
offshore (to 80 km), enhancement of phytoplankton production (as evidenced
by elevated chlorophyll concentrations) apparently occurs (Riley 1938). The
south Texas shelf can be divided into several zones, based on the source of
315
-------
freshwater runoff (Kamykowski and Van Baal en 1979). The nearshore zone (to
26 km from shore) is influenced solely by runoff from the Texas rivers,
while an offshore zone (59-70 km from shore) is influenced solely by
Mississippi River water. Between these zones (26-59 km from shore), two
mixing zones occur: an inner zone of primarily Texas river water, and an
outer zone of primarily Mississippi River water. Beyond 59 km from shore,
increases in surface chlorophyll appear to be correlated with decreases in
salinity. Inshore, phytoplankton biomass undergoes a strong seasonal cycle,
but the magnitude of the seasonal changes decreases with distance from
shore.
Whereas the open waters of the Gulf of Mexico are dominated by
nanoplankton, especially coccolithophores, the shelf waters are dominated by
netplankton, notably diatoms (cf. Hulburt and Corwin 1972). Changes in the
abundance of netplankton are largely responsible for the seasonal cycles in
phytoplankton abundance nearshore (Kamykowski and Van Baal en 1979).
It has been suggested (Iverson and Hopkins 1981) that the Mexican
Current (a western boundary current in the Gulf of Mexico analogous to the
Gulf Stream but smaller in size) may enhance phytoplankton productivity
along its western edge by cross-stream transport of nutrient-rich water into
the euphotic zone. This supposition requires further study for
verification, however.
Zooplankton collected over the Texas continental shelf with 233-um mesh
nets were dominated by copepods (Park 1975, 1976; as cited by Iverson and
Hopkins 1981). The dominant species varied with distance from shore;
calanoid copepods (e.g., Paracalanus, Clausocalanus, and Acartia) were
abundant nearshore, while cyclopoid copepods (e.g., Farranula, Oithona,
Oncaea) contributed significantly over the outer sheTTiOFfier abundant
groups included ostracods, mollusks, chaetognaths, and larvaceans.
Zooplankton abundance and biomass decreased, and species diversity
increased, with increasing distance from shore. As for phytoplankton,
zooplankton abundances had the greatest seasonal variations nearshore, and
these variations decreased with distance from the shore. Radiolan'ans were
important components of the microzoopl ankton over the Texas shelf (Casey
1976, as cited by Iverson and Hopkins 1981).
Some pelagic fishes of the open Gulf of Mexico are also common in
waters over the continental shelf (e.g.., dolphin); other abundant pelagic
fishes may be more or less confined to coastal waters [e.g., Spanish
(Scomberomorus maculatus) and king (S. caval la) mackerels, bluefish
(Pomatomus saltatrix). little tunny (EutTiynnus alletteratus); (cf. Gulf of
Mexico and South Atlantic Fishery Management Councils 1981). Some marine
mammals [notably bottlenose dolphins (Tursiops truncatus)] are largely
confined to coastal waters in the Gulf of Mexico.
Due to the relatively shallow water column over the continental shelf,
there is essentially no mesopelagic fauna there.
Benthic communities on the continental shelf of the western Gulf of
Mexico are generally separated into three distinct communities, whose
316
-------
boundaries are delineated by type of substrate, water depth, and distance
from shore. The soft-bottom communities are separated into white-shrimp
(Penaeus setiferus) grounds (shore to approximately 22 m depth) and
brown-shrimp (P. altecus) grounds (22 m to at least 90 m depth, and perhaps
farther offshore) (Hildebrand 1954). Each has its own characteristic
invertebrate and fish faunas. Nearshore disposal of manganese nodule
processing wastes is not considered to be a viable option along the Gulf
coast, and therefore the discussion of soft-bottom benthic communities which
follows will be limited to the brown-shrimp grounds of the outer shelf.
Along the seaward margin of the continental shelf of the western Gulf of
Mexico are found a series of hard-bottom banks or reefs, which have a fauna
distinct from the surrounding soft-bottom communities (Bright et al., 1981).
Due in part to the commercial importance of the brown shrimp,
considerable attention has been given to studying the benthic macrofauna of
the brown-shrimp grounds. Included are studies of both the epibenthic
macroinvertebrates (cf. Hildebrand 1954) and the demersal fishes
(cf. Chittenden and McEachran 1976). While these studies have concentrated
on waters less than 110 m depth, little work has been done on the benthic
communities between 110 m and the edge of the continental shelf (about
182 m). Chittenden and McEachran (1976) contend, however, that since only a
narrow portion of the shelf lies between 110-182 m depth, the area may only
represent a transition zone between the brown-shrimp grounds and the
communities of the upper continental slope. Although the epibentic
macroinvertebrates of the brown-shrimp grounds are reasonably well-known,
little work has-been done on the benthic infauna, especially the meiofauna
(Thistle and Lewis 1981).
Hildebrand (1954) reported that the dominant invertebrates of the
brown-shrimp grounds included the brown shrimp, a crab (Callinectes danae),
a bivalve (Pi tar cordata), a conch (Busycon contrarium). and a starfish
(As t ro p ec t en a n 1111e n s i s). He also listed the characteristic demersal
fishes as being a flounder (Syacium gunterii) and the butterfish (Poronotus
triacanthus). Hildebrand's (1954) study was confined to the inshore portion
of the brown-shrimp grounds, however, and since species diversity tends to
increase with depth across the shelf (Chittenden and Moore 1977), it is not
surprising that other demersal fish species are more abundant farther
offshore. Chittenden and Moore (1977) report, for instance, that the three
most abundant demersal fishes at 110 m depth were the longspine porgy
(Stenotomus cap/inus), the wenchman (Pri sti pomoides aquilonaris), and the
Mexican searobfn (Wionotus paralatus).
Fishes characteristic of the brown-shrimp grounds are less likely to be
dependent on the estuaries for spawning and/or nursery purposes than are the
fishes characteristic of the white-shrimp grounds inshore (Chittenden and
McEachran 1976). The brown-shrimp grounds represent a more stable
environment, less subject to temperature or salinity variations, than the
white-shrimp grounds, and consequently it is not surprising that species
diversity is higher on the brown-shrimp grounds. Seasonal variations in
abundance are also less pronounced on the brown-shrimp grounds.
317
-------
The type of substrate obviously plays a large role in determining the
type of fauna found in a given area. Williams (1958) found that shrimp
actively select the type of substrate they are associated with; white and
brown shrimps are found on the terrigenous muds common along the Texas and
Louisiana coasts, while pink shrimp (Penaeus duorarum) occur over calcareous
substrates (e.g., on the Campeche Bank north of the Yucatan Peninsula). The
fact that shrimps select the type of substrate they are associated with may
be of critical importance when considering possible implications of the
disposal of manganese nodule processing wastes on the shelf. Chittenden and
McEachran (1976) suggest that the fish characteristic of each area may also
be influenced by substrate type.
As mentioned above, hard-bottom communities exist on a series of banks
occurring on the seaward half of the continental shelf in the western Gulf
of Mexico. Bright (1977) has grouped these banks into three categories
based on their biota and depth of origin. The first group includes banks
originating in 50-60 m of water and cresting at depths of less than 25 m.
The biota of these banks is dominated by fire coral (Millepora alcicornis)
and various sponges. Banks representative of this group include Stetson and
Sonnier Banks south of Louisiana (Bright et al., 1981). The second group
includes a number of banks which do not rise as close to the surface as
banks of the other two groups. The biota of these banks includes
antipatharian black corals (Cirripathes spp.). encrusting coralline algae,
and gorgonians. Banks representative of this group include the South Texas
Banks off the southern Texas coast (Bright et al., 1981). The third group
includes banks originating at depths of 100-200 m, and is typified by the
East and West Flower Garden Banks south .of Louisiana. These two banks bear
the most complete and complex coral communities on the northwestern Gulf of
Mexico continental shelf (Bright et al., 1981). They are, however,
climatological ly near the limits of existence for many of the resident
species, and at least partially isolated from the gene pool. Bright et
al. (1981) suggest that because of this geographical separation, they are
susceptible to collapse should the existing populations be destroyed. These
banks are of particular research interest because the biotic zonation at the
Flower Gardens has been described as one of the most extensive of all Gulf
of Mexico banks (Bright et al., 1981). Potential threats to these reefs
already include increased oil and gas drilling in the area, their close
proximity to major shipping lanes, and increased recreational use. The
possible disposal of manganese nodule processing wastes in this area would
likely pose another threat to their continued existence.
The topographic relief of the aforementioned reefs and banks is
important habitat for various tropical reef fishes. These include snappers
(Lutjanidae), groupers and sea basses (Serranidae) , tilefishes
(Branchiostegidae), jacks (Carangidae), triggerfishes (Ball istidae), wrasses
(Labridae), grunts (Pomadasyidae), and porgies (Sparidae). Chittenden and
McEachran (1976) suggest that as for the corals, the northwestern Gulf of
Mexico is a near-marginal environment for many of these fishes, and that
species least tolerant of lowered winter temperatures may be absent from the
northern Gulf.
318
-------
Nearshore Environments of the Western Gulf of Mexico--
As mentioned above, nearshore disposal of manganese nodule processing
wastes is not considered to be a viable option along the Gulf Coast.
Consequently, nearshore environments of this area will not be discussed
herein.
Western Gulf of Mexico Fisheries-
Fisheries considered in this section occur in the western half of the
Gulf of Mexico, which lies off the coasts of Louisiana and Texas. The
gulf's continental shelf is the primary fishing area. The waters of the
north central gulf which include fishing areas for shrimp (Penaeus spp.),
menhaden (Brevoortia patronus), and bottomfish species may be considered
"among the most productive fishing grounds in the world" (Thompson and
Arnold 1971). Gulf fisheries currently account for approximately 25 to 37
percent by weight of the total U.S. landings (Pequegnat et al., 1978).
Estuaries are an integral part of the life cycles of many of the
economically important fish species in this region. It is estimated that
more than 90 percent of the U.S. gulf commercial catch is made up of species
that spend part or all of their lives in estuarine areas (Thompson and
Arnold 1971). Moreover, nearly all of the gulf coast catch, including most
of the menhaden, is made within a few miles of the coast (Pequegnat et al.,
1978). Among the important commercial fishes, only groupers and red
snappers (Lutjanus campechanus) are caught beyond the 12-mi limit; combined
they constitute only about 1 percent of the volume and 2 percent of the
value of the total gulf catch (Pequegnat et al., 1978).
In 1980, Texas and Louisiana commercial landings totaled 684,833 mt,
valued at $331.9 million (Resource Statistics Division 1981). Landings from
the two states represented 77 percent of the entire gulf catch and accounted
for 72 percent of the total gulf landing value during 1980.
Approximately 75 percent of the gulf fish catch is used for fishmeal,
oil, or other processed products (Thompson and Arnold 1971). The most
valuable gulf fishery is for the various shrimp species (Thompson and Arnold
1971). The gulf shrimp fisheries account for 67 percent of the catch by
weight and 83 percent of the ex-vessel value of U.S. shrimp landings (GMFMC
1980a).
Fishing Areas--Brown shrimp (Penaeus a 2 tec us) fishing grounds are
located along the Texas and Louisiana coasts.The fishery occurs in depths
to 91 m, but is generally conducted in waters of less than 55 m (GMFMC
1980a). The annual catch of brown shrimp for the entire gulf during
1959-1975 averaged 27,397 mt (GMFMC 1980a).
Fishing areas for white shrimp (Penaeus setiferus) occur primarily
along the Louisiana coast and in the Campeche Bank area off the Yucatan
Peninsula. This is a shallow water fishery generally conducted at depths
less than 27 m. The largest U.S. catches occur in the area west of the
Mississippi River to Freeport, Texas (GMFMC 1980a). Annual landings of gulf
white shrimp during 1959-1975 averaged 14,878 mt (GMFMC 1980a).
319
-------
Minor fisheries for royal red shrimp (Hymenopenaeus robustus) and
seabobs (Xiphopenaeus kroyeri) also occur in the western gulf. The
deepwater royal red shrimp are harvested at depths of 183 to 549 m in the
area southeast of the Mississippi River Delta (GMFMC 1980a). During
1959-1975, annual gulf landings of royal red shrimp averaged 376 mt (GMFMC
1980a).
Seabobs are caught incidentally to other shrimp fisheries in waters
shallower than 13 m primarily off the Louisiana coast (GMFMC 1980a). Annual
gulf landings of seabobs during 1959-1975 averaged 635 mt (GMFMC 1980a).
The average annual ex-vessel value of the gulf shrimp fisheries during
1970-1977 was $183.5 million (GMFMC 1980a). Texas accounts for 42 percent
of the average shrimp catch value, followed by Louisiana at 36 percent
(GMFMC 1980a). Brown shrimp is the most valuable species, accounting for 56
percent of the average shrimp catch value during 1968-1977, followed by
white shrimp which contributed 30 percent (GMFMC 1980a).
The densest concentrations of groundfish occur in the inner shelf areas
of the gulf (depths less than 64 m) over silty-clay substrates (GMFMC 1981).
The principal fishing grounds for species utilized in the production of fish
meal, oil and other processed products occur east of the Mississippi delta
(GMFMC 1981). Atlantic croaker (Micropogon undulatus) is the target species
for this fishery, accounting for 69 percent by weight of the catch (GMFMC
1981).
The commercial groundfish food fishery is centered near Southwest Pass,
Louisiana, in water depths of 9 to 36 m (GMFMC 1981). The important species
include Atlantic croaker, spot (Leiostomus xanthurus), sand seatrout
(Cynoscion arenarius). and silver seatrout (C. n'othus) (GMFMC 1981).
Although not target species, Atlantic cutlassfish (Trichiurus lepturus) and
sea catfish (Arius felis) are also abundant in trawl landings.
Total annual landings of groundfishes are approximately 56,000 mt, of
which 50,000 mt are utilized for petfood and 6,000 mt for human consumption
(GMFMC 1981).
Gulf of Mexico menhaden support the largest domestic fishery in terms
of quantity of landings. Although three menhaden species occur in the gulf,
a single species, (Brevoortia patronus) comprises over 99 percent of the
menhaden catch (Nicholson 1978). The fishery for fishmeal and oil is
cantered between Empire and Intracoastal City, Louisiana (Nicholson 1978).
Between 85 and 90 percent of the purse seine sets are made within 24 km of
shore in this area (Nicholson 1978). Over 95 percent of the menhaden catch
is comprised of 1- and 2-year old fish.
The Gulf menhaden catch during 1979-1980 averaged 740,724 mt with an
average value of over $71 million (Resource Statistics Division 1981).
During 1970-1973, over 80 percent of the menhaden catch was made in
Louisiana, while Texas landings accounted for approximately 4 percent
(Nicholson 1978).
320
-------
The reef fisheries of the Gulf of Mexico target on demersal snappers
(lutjanids, 15 spp.), groupers (serranids, 15 spp.), and seabasses
(Centropristis spp.) (GMFMC 1980b). The red snapper (Lutjanus campechanus)
is the primary target species along with other Lutjanus spp. in the western
gulf. Directed reef fisheries for groupers and the yel1owtai1 snapper
(Ocyurus chrysurus) are confined to Florida waters (GMFMC 1980b). The hook
and line reef fisheries are conducted in waters overlying the continental
shelf (< 183 m depth) (GMFMC 1980b). Productive fishing areas are
associated with reefs or reef-like hard bottoms. Overall, the reef
fisheries are of lesser importance in the western gulf than in the eastern
gulf, where over 87 percent of the reef fish landings occur (GMFMC 1980b).
During 1970-1976, gulf commercial reef fish landings have ranged between
7,496 mt (1973) and 8,532 mt (1970), with an average value of $8,013,000
(GMFMC 1980b).
The reef fish stocks in many gulf areas may already be severely
depleted due to overexpl oitation. The Gulf of Mexico Fishery Management
Council has designated particular areas as stressed in terms of resource
abundance. In the western gulf, the region extending from the
Louisiana-Texas state l.ine to the 95° meridian out to the 30 m depth contour
is considered a stressed area by the council (GMFMC 1980b).
There is great potential for expanding and/or developing other
fisheries in the Gulf of Mexico, High seas pelagic species which could
support domestic fisheries include tunas and tuna-like fishes ("scombrids),
flying fishes (exocoetids), sharks (carcharhinids) and billfishes (Xiphias
gladius, istiophorids ). Iwamoto (1965) reported that commercial ly
exploitable stocks of four species of tuna [skipjack (Euthynnus pel ami s),
yellowfin (Thunnus ajbacares), blackfin (_T. atlanticus), bluefin
(_T. thynnus)] are found in the northern gulf area, especially in waters
overlying the continental slope between the 183-m and 1,830-m depth
contours. In the northern gulf, sharks and billfishes are abundant in the
Mississippi Delta area (Bullis et al., 1971). Coastal pelagic schooling
fish such as anchovies (Anchoa spp.) are also abundant but underutilized in
the delta region. Gulf shel f bottomfishes (e.g., sciaenids, demersal
sharks) and shellfish (e.g., lobsters, crabs, clams) are also abundant and
could support major fisheries. At present, the commercial fishery potential
of the continental slope of the northern Gulf of Mexico is not being
exploited in any systematic way (Pequegnat et al., 1976). Exploratory
bottom longlining operations in this area (Nelson and Carpenter 1968) have
revealed commercial quantities of fishes [notably tilefish (Lopholatilus
chamael eonti ceps) and yellowedge grouper (Epinephelus fl avolimbatus)] at
depths of 183 to 365 m over the continental slope, especially off the Texas
coast.
In summary, the major western Gulf of Mexico fisheries are conducted in
relatively nearshore shelf waters. The most valuable domestic fishery for
shrimp occurs in the coastal regions of Texas, Louisiana, and Mississippi.
The largest U.S. fishery for menhaden is also conducted primarily in the
nearshore areas of Louisiana. Therefore, selection of a site for the
disposal of manganese nodule processing wastes should include consideration
321
-------
of potential impacts on these highly productive fishing grounds. Due to the
potential importance of currently unexploited fish stocks over the
continental slope, the potential impacts of waste disposal there should also
be evaluated.
Fishery Biology—The general life cycles of the important gulf shrimp
species are similar. Adult brown shrimp spawn during spring through early
summer in water depths of less than 18 m. Year-round spawning takes place
at depths of 46 to 110 m (GMFMC 1980a). White shrimp typically spawn
repeatedly during spring through fall at depths ranging from 7 to 31 m
(GMFMC 1980a). Brown and white shrimp larvae are pelagic and are
concentrated off the Texas coast. Brown shrimp larvae are abundant during
August to November in water depths of 27 m and are also found in large
concentrations at depths ranging from 48 to 82 m during September to
November (GMFMC 1980a). White shrimp larvae are found in shallower areas
(14 m) offshore of Texas during May to August.
It has been suggested that brown shrimp postlarvae burrow into offshore
substrates to overwinter prior to entering estuaries (GMFMC 1980a).
Estuaries serve as important nursery areas for brown and white shrimp.
Their food consists of detritus, algae, and microfauna (GMFMC 1980a).
Juveniles enter the coastal estuaries during spring through early fall.
Brown shrimp adults migrate from the estuaries into the gulf fishing grounds
from May through November (GMFMC 1980a). The adult white shrimp migration
period is somewhat later, occurring during September through November (GMFMC
1980a).
Royal red shrimp and seabobs are not estuarine dependent. The life
cycles of these species occur entirely within the offshore waters of the
gulf. Royal red shrimp spawn during the winter and spring months and
seabobs reproduce during July through December (GMFMC 1980a).
Adult shrimps are opportunistic omnivores and subsist on a variety of
plant and animal material. Brown shrimp, white shrimp, and seabobs prefer
substrates consisting of soft mud or peat with large amounts of decaying
organic matter or vegetation (GMFMC 1980a). Royal red shrimp have no
apparent substrate preferences, and are found on sand, silty sand, or
calcareous sediments (GMFMC 1980a). Shrimps, once offshore, do not
generally display extensive migrations, although some onshore-offshore
movements have been documented (GMFMC 1980a).
Many of the groundfish species harvested in the western Gulf of Mexico
share common life history characteristics. Spawning occurs in the gulf and
early developmental stages inhabit the estuaries (GMFMC 1981). During late
juvenile stages, there is an offshore migration. Adults predominate in
nearshore coastal areas of the gulf. Highest densities of groundfishes
occur over shallow, silty clay regions (GMFMC 1981). Water temperatures
influence migratory patterns; adults move shoreward during the summer and
retreat offshore during winter months (GMFMC 1981).
322
-------
Rapid growth and high natural mortality rates are characteristic of
most groundfish species (GMFMC 1981). A variety of benthic organisms are
preyed upon by groundfishes.
During fall and winter, adult menhaden move offshore to overwinter in
inner and mid-shelf areas. It is believed that spawning occurs during this
period (Gallaway and Strawn 1974). During the following fall and winter,
larvae enter estuaries where they feed on phytoplankton and detritus
(Gallaway and Strawn 1974). Adults return to nearshore areas in the spring
and are abunda.nt in near surface waters until fall (Gallaway and Strawn
1974).
Similar to juveniles, adult menhaden are also pianktivores, feeding
primarily on phytoplankton.
Little specific life history information is available for reef fishes.
For red snapper, the major species in the fishery, spawning occurs on the
gulf shelf during June to October (GMFMC 1980b). Adult red snapper are
found in areas associated with coral reefs or limestone outcroppings (GMFMC
1980b). During the winter, adults congregate at depths of 30 to 65 m. An
inshore movement occurs during the summer to depths of 20 to 30 m (GMFMC
1980b). Extensive migrations have not been demonstrated for red snapper;
older, larger fish tend to be distributed in deepwater areas to the edge of
the continental shelf (GMFMC 19805).
Shrimp grounds are nursery areas for juvenile croakers, which occur in
depths of 10 to 35 m over saad or mud substrates (GMFMC 1980b). Juveniles
primarily forage on shrimp. Adult croakers are presumed to be bottom
feeders taking a variety of fishes and squid.
Summary--Common characteristics of the species of economic importance
in the western Gulf of Mexico include shelf spawning, pelagic larvae, and
estuarine nursery areas. Due in part to the commercial importance of the
gulf fisheries and their almost total dependence on coastal and estuarine
waters, nearshore disposal of manganese wastes is not contemplated for the
gulf area. However, it is important that the shelf spawning areas and the
distribution of pelagic larvae be considered in selecting an offshore waste
disposal site in the gulf.
The productive habitats of the commercial species must also be
considered prior to selecting a disposal method and location. Special
consideration should be given to shrimp and groundfish fishing areas as well
as regions including coral reefs or limestone outcroppings, which are
important to reef fishes.
SOUTHERN CALIFORNIA BIGHT
Physical Characteristics
The southern California Bight, which extends from the California-Mexico
boundary northward to Point Conception (Figure 63) is morphologically
classed as a continental borderland. The profile of this type of
323
-------
120*W
119'
117*
34°N
90.70
:-::: LOS; ^vXvX::-:-:-:::-:-:-:-:-:
::;: ANGELES
REFERENCE: Uchupi and Emery. 1963.
Figure 63. The southern California Bight.
324
-------
continental margin is much more irregular than the marginal plateau,
shelf-rise and marginal depression types of margins which also exist along
the western coast of North America (Figure 64). The southern California
continental margin consists of a very narrow shelf down to approximately the
100 m (328 ft) depth, a limited basin slope, a relatively wide borderland
having a series of basins and interbasin ridges, and a true continental
slope which extends to the deep-sea floor. Within the borderland there are
more than 20 basins extending as deep as 3,000 m (9,842 ft) separated by
submarine ridges, banks, and islands which reach elevations of 500 m (1,640
ft) above sea level (Uchupi and Emery 1963). The basins contain thick
sediment fills whereas the higher areas consist of sedimentary, igneous, and
metamorphic rocks. Shelves around the islands and along the mainland coast
resemble typical continental shelves except for being much narrower. A
number of submarine canyons cut across the shelf providing pathways for
offshore transport of coastal sediments. The seaward boundary of the
borderland province is distinguishable by a continental slope followed by an
8 to 20 km (4.3 to 10.8 nmi) wide ridge at depths of 400 to 1,600 m (1,312
to 5,249 ft). Beyond the ridge the topography deepens abruptly, dropping to
the ocean basin at 3,400 to 3,800 m (1.8 to 2.1 nmi).
Bathymetry—
Continental Shelf--The Bight continental shelf ranges in width from
about 1 to 23 km (0.54 to 12.4 nmi), averaging 6.5 km (3.5 nmi) and extends
down to a depth of approximately 200 m (656 ft). Maximum widths of greater
than 12 km (6.5 nmi) occur at four places; the U.S.-Mexican border, San
Pedro Bay, Santa Monica Bay, and east of Santa Barbara (Figure 63).
Although each area is at the mouth of a river, the added width cannot be
attributed to delta formation since rocky bottom prevails at each site.
Irregular rocky bottom, present at many places on the mainland shelf, is
even more common on the island shelves, and is most abundant on the flat
bank tops. In addition to these rocky areas, the shelves and bank tops have
a series of step-like terraces similar to those on adjacent land areas
(Emery 1960).
The southern California coast has been dynamically active throughout
its history. Seismic activity and sea level changes have changed the
position and shape of the coastal area significantly. Upland erosion has
contributed vast quantities of sediments to the coastal waters with ultimate
deposition in the deep basins. The detrital material is afforded passageway
to the deeper areas via numerous canyons incising the mainland shelf. Major
submarine canyons in the southern California Bight include Scripps, La
Jolla, San Gabriel, Redondo, Santa Monica, Dume, Mugu, and Hueneme. Of all
the sediments of the mainland shelf, those composed of detrital fragments
are by far the most common, and an estimated 80 percent of the shelf surface
is covered by such sand-sized sediments.
Continental Slope—Off .southern California the continental slope
descends from an outer deep ridge of the borderlands to a depth of about
3,400 to 3,800 m (1.8 to 2.1 nmi) (Uchupi and Emery 1963). Much of the
slope is continuous from the crest of the ridge down to the continental
rise. However, in some areas it is discontinuous, with breaks marked by
325
-------
MARGINAL PLATEAU
CO
ro
cr>
CONTINENTAL BORDERLAND
-1
-2
-3 KM
D
MARGINAL DEPRESSION
KILOMETERS
VERTICAL EXAGGERATION 15 X
tl
0
-I
-2
-3
-4KM
N
/N
REFERENCE: Curray 1969
Figure 64. Profiles illustrating morphological types of continental margins off of
western North America.
-------
spur-like ridges which are 50 to 100 m (164 to 328 ft) high. The
continental slope in this region has an average width of about 10 km (5.4
nmi) and its gradient ranges from 10° to 17°, averaging about 12°. The
slope has a northwest trend and is in line with slopes in regions to the
north and south. Submarine canyons have not been recognized on the slope
although several gaps and offsets are present.
Continental Rise--The rise off southern California is poorly developed
or missing, and its position at the slope's base is occupied by a shallow
marginal trench. Where present, the rise is only a few tens of kilometers
wide and is very irregular. In this region the surface of the rise is
broken by three seamounts, only the largest of which (San Juan) has been
surveyed and named. It is 33 km (17.8 nmi) long, 3,000 m (9,842 ft) high,
and oriented in a northeasterly direction. Deep-sea channels are also
present on the continental rise but are not common.
Abyssal Sea Floor--The topography of the abyssal sea floor off
California is of diastrophic origin (volcanic, faulting, and folding) except
where sediments have blanketed it (Emery 1960). South of Point Conception,
bottom smoothness ceases and the topography is highly irregular due to
sediment from the land being intercepted by the basins of the continental
borderland. Numerous seamounts are also present on the abyssal floor. One
of these, San Juan Seamount (near 33°N, 121°W), has the appearance of a
volcano; however, others have flat tops. Since erosion is virtually
nonexistent on the abyssal floor, the flat tops suggest planing off during a
lower relative stand of the sea.
Circulation Patterns—
In the north Pacific Ocean, strong westerly winds at high latitudes
move the water eastward, and the strong and constant trade winds farther
south push the water westward. Both the winds and the water in the north
Pacific Ocean go through a large clockwise circulation pattern called the
North Pacific Gyre. The northern limb of the Gyre feeds the southward flow
along the west coast of the United States. Beneath this flow and
concentrated over the continental slope is a northward flow. These two
currents essentially form the California Current System.
There is some confusion in nomenclature used for the currents
comprising the California Current System. Following Mickey's (1979a)
convention, the California Current refers to the southward flow, the
California Undercurrent refers to the northward flow at intermediate depths
over the continental slope, and the Davidson Current refers to the northward
surface flow that occurs north of Point Conception during the fall and
winter. The Southern California Countercurrent refers to the northward flow
which is found south of Point Conception, inshore of the Channel Islands in
the California Bight. Thus, the California Current System is comprised of
the southward California Current and the northward flowing California
Undercurrent, Davidson Current, and the Southern California Countercurrent.
California Current—The title "California Current" applies to all
southward flows in the North Pacific Gyre adjacent to the west coast of the
327
-------
United States (Reid et al., 1968). It is a broad [500 to 1,000 km (270 to
540 nmi)], weak (5 to 10 cm/sec), southflowing eastern boundary current
extending from Washington to Baja California. Reid (1965) states that it
has become common to arbitrarily define the western boundary of the
California Current at a distance of 1,000 km (540 nrm ) from shore. The
water carried south by the California Current is cooler than the waters
farther offshore and is also characterized by its low salinity, high oxygen,
and high phosphate.
At most latitudes, there exist two regions of strong southward flow.
The nearshore region is most fully developed in spring and early summer
south of Cape Blanco. The offshore region is most fully developed in late
summer or fall. Its mean annual location appears to be about 430 km (232
nmi) from the coast off Cape Mendocino and 270 km (146 nmi) off Point
Conception. South of Point Conception, the offshore region of southward
flow moves somewhat closer to the coast so that off Cape San Lazaro, Mexico,
the nearshore and offshore regions of southward flow are not usually
distinct (based on available data). From Cape Mendocino southward, a second
offshore region of strong southward flow occurs year-round. The region
moves closer to shore toward the south, being 850 km (459 nmi) offshore at
Cape Mendocino and 500 km (270 nmi) off Cape San Lazaro.
California Undercurrent — The California Undercurrent flows northward
below the California Current, at intermediate depths beneath the pynocline
and seaward of the continental shelf. It is much narrower [approximately 50
km (27 nmi) in width] than the overlying southward-flowing California
Current. The Undercurrent is sometimes referred to as the California
Countercurrent, which should not be confused with the Southern California
Counter Current discussed in the following section. The Undercurrent, which
is believed to have the Equatorial Pacific water mass as its source, is
characterized by high temperature, salinity, and phosphate concentrations,
but is low in dissolved oxygen.
The observations of the California Undercurrent have been made all
along the coast through development of dynamic topographies and by direct
current measurements (Hickey 1979a). Reid and Schwartzlose (1962) first
presented the evidence that the northward flow might have a relatively
narrow, high speed core. Drogue measurements along lines at 30°N and 36°N
have indicated a northward flow with widths of 30 to 70 km (16 to 38 nmi),
and maximum speeds of 15 to 20 cm/sec. The measurements of Wooster and
Jones (1970) indicated an undercurrent jet in August, 1966, off northern
Baja California. The jet at between 200 and 500 m (656 and 1,640 ft) had a
width of about 20 km (10.8 nmi), a thickness of 300 m (984 ft), and an
average speed of 30 cm/sec. A similar jet (Figure 65) was observed with
direct current measurements off Washington during July-September (Hickey
1979a). The width over the slope was 20 km (10.8 nmi), the thickness was
about 200 m (656 ft), and the maximum current speed at the core was 16
cm/sec.
Southern Cal i forni a Counter Current — Flow in the region from Point
Conception to San Diego has tfeeni described in terms of the Southern
California Eddy (Schwartzlose 1963), or Countercurrent (Sverdrup and Fleming
328
-------
100
DISTANCE: OFFSHORE < km)
80 60 40
20
- IOOO
- IIOO
REFERENCE: Hickey, 1979a.
Figure 65. Current meter data averaged from July 21 to
August 28, velocity units are in cm/sec.
Regions of southward flow are shaded.
329
-------
1941). Generally, the flow is referred to as a countercurrent only when
northward flow extends north around Point Conception (Reid 1965). When the
mainstream of the California Current approaches the coast, some of the water
turns southward and some northward, so that an "eddy" is formed north of
Point Conception. The southernmost tip of the eddy can reach as far south
as San Diego. The seasonal and spatial variations in the flow have been
intensively investigated through dynamic topography development (Wyllie
1966) and by current measurements (Schwartzlose 1963). Dynamic height data
indicate that northward flow is found in the upper half of the California
Bight except during April, and in the lower half of the Bight except from
January to May. The northward flow is fed by the mainstream of the
California Current which turns eastward near 32°N. The axis of the eddy
usually occurs several hundred kilometers offshore, roughly in line with the
coastline north of Point Conception.
Northward flow in the Bight is sometimes continuous with the Davidson
Current, particularly during winter months when the term countercurrent
rather than eddy is commonly used to describe it. However, the relative
infrequency with which drift bottles released in the Bight are retrieved
north of Point Conception suggests that the northward flow usually
contributes the majority of its volume to reci rcul ation in the California
Current. Drift bottle data also suggest that a wind-driven coastal current
occurs inshore of the northward flow that forms the eddy.
Representative Areas
The physical oceanographic characteristics of three southern California
Bight disposal areas are presented in the following section; a shelf/canyon
area, a borderland basin area, and finally a deep ocean basin area. The
information presented represents a synthesis of data obtained by review of a
large number of references (Table 53).
Shelf/Canyon —
Shelf temperature profiles determine the local density structure much
more than salinity, and change markedly from season to season (Figure 66).
In summer there is a shallow warm layer which rarely exceeds 5 m (16 ft) in
thickness, followed by a 20 m (66 ft) thermocline having a gradient of
0.25°C per meter, and an isothermal (10°C) bottom layer. In the winter, the
difference between the mean surface and bottom temperatures is significantly
reduced to 2.3°C, being only slightly colder at the bottom. Below 20 m (66
ft), the normal winter cooling is reversed, a common feature on the west
coast shelf (Huyer 1977). The average shelf temperature is 15°C during the
summer and 13.6°C during the winter.
Horizontal currents on the Southern California continental shelf are
variable, having root mean square changes in a few hours to 10 days which
typically exceed the seasonally averaged mean values. Typical speeds
observed on the nearshore shelf are from 7 to 10 cm/sec, but can vary
between no current and 50 cm/sec (Hendricks 1975). During spring and
summer, when the water column is thermally stratified, surface and bottom
currents may be opposed, whereas during fall and winter, the water column is
less stratified and the flow structure is more unidirectional (Figure 67).
330
-------
TABLE 53. REFERENCES REVIEWED TO COMPILE PHYSICAL OCEANOGRAPHIC
INFORMATION ON CHARACTERISTIC DISPOSAL AREAS IN THE
SOUTHERN CALIFORNIA BIGHT
Dodimead et al., 1963
Wyllie 1966
Uchupi and Emergy 1963
Emery 1960
Hickey 1979a
Reid et al., 1968
Reid 1965
Reid and Schwartzlose 1962
Wooster and Jones 1970
Hickey 1979b
Sverdrup and Fleming 1941
Schwartzlose 1963
Huyer 1977
Winant and Bratkovich 1981
Hendricks 1975
Hendricks 1980
Wyllie and Lynn 1971
331
-------
SPRING SUMMER FALL WINTER
E
c\
i
§
>
0
m
<
ui
o
I£
£
w
Q
60
40
20
* *x
*• X
* X
*x
" . * . . ,
*
*•
'*•
*
" . *•*,
^
20
* • X
* • X
*• X
, * X t ,
4c
* •
*•
1 4* I
10 U * • x L -I
I i * • r i 1 i i *P
0 10 20 0 10
• X
X
X
X
^J_J
*»x
*•*
*• X
*• X
*• x
*• x
*• X
*«x
*;*
*«x
! **x
I 1 1 1 J
^
• X
X
X
K I
*• X
*»x
$•3?
i I* f Xi 1
^•x
*»x
- |:xx
, J»X i i
• x r *«x r 5f «j<
i X 1 i i T *(f . 1 pf «r i i i
20 0 10 20 0 10 20
TEMPERATURE (°c)
• MEAN
x MAXIMUM
* MINIMUM
60m
30m
15m
REFERENCE: Winant and Bratkovich. 1981.
Figure 66. Mean, maximum, and minimum temperatures at each
depth and during each deployment on the southern
California Shelf.
332
-------
SPRING
SUMMER
FALL
WINTER
I
60
40
,
§«
CD
<
LU 20
O
z
10
0 i—«-
-20
•
• •
1.
20-20 0 20-20 0 20 -20
LONGSHORE CURRENT (cms-1)
• .
•
••
•
1 1
•
• _
•"
i i
i i
1 1 f 1 t
20 0 20
60m
30m
15m
REFERENCE: Winant and Bratkovich, 1981.
Figure 67. Distribution of mean longshore currents on the
southern California Shelf. A positive value
corresponds to a current to the north.
333
-------
Mean surface currents in all seasons sweep to the south. At their weakest
during the fall they still exceed 2 cm/sec. Although the current structure
has been found to be similar in 60, 30, and 15 m (197, 98, and 49 ft) of
water, the amplitude of mean currents is substantially reduced at shallower
stations.
The largest vertical shear in mean longshore velocities occurs during
the summer. During this season the near-surface currents [measured 4 m (13
ft) beneath the surface in 60 m (197 ft) of water] have been oriented
downcoast (southward) with a velocity of 6.2 cm/sec, whereas 28 m (92 ft)
deeper the mean current was reversed, with an upcoast velocity of 4.1
cm/sec. The velocity difference over the entire water column is reduced to
5 cm/sec at the 30 m (98 ft) location, and to 1 cm/sec at the 15 m (49 ft)
location. Cross-shelf current measurements averaged over a relatively short
period of deployment were within error of zero for each instrumented
location. The observations are thus unable to resolve any mean cross-shelf
circulation patterns associated with upwellings and downwel 1 ings. The
temporal variability in along-shore currents can be significant, however.
Hendricks (1975) reports amplitude changes of greater than 20 cm/sec within
a day, and significant differences in average 3-day velocities within a
week's time (Figure 68). Median speeds at the 41 m (135 ft) depth have been
measured at 10.7 cm/sec in Santa Monica Bay and 9.4 cm/sec off the Palos
Verdes peninsula (Hendricks 1980). Figure 69 presents a measured velocity
distribution for shelf, canyon, and slope stations in the California Bight.
Canyon flows are expected to differ from those of the nearby shelf due
to the channeling effect of the canyon walls. Higher axial current speeds
occur near the heads of submarine canyons at a more frequent interval than
at other bottom sites. Persistent down canyon flows have been measured
(average 5.5 cm/sec) for as much as 22 days. About 5 percent of the time,
speeds have exceeded 27 cm/sec, which is sufficiently strong to resuspend
organically enriched sediments. It should be noted that upcanyon movement
can occur as well. Although a downcanyon speed of 3.8 cm/sec was observed
at the 384 m (1,260 ft) depth of the Santa Monica Canyon one year, during
another, net movement was upcanyon at 3.3 cm/sec at the 168 m (550 ft)
depth. Periodic turbidity currents are known to flush accumulated bottom
material down canyon axes and into basin or outer shelf areas.
Background dissolved oxygen (DO) levels at a shelf disposal site will
be similar to that at the shoreward CalCOFI line 9 station (90.28) located
in approximately 200 m (656 ft) of water (see Figure 70). Surface values
remain fairly constant near 8.6 mg/1 during the spring months, decreasing to
7.9 mg/1 in the winter. At 100 m (328 ft), however, the dissolved oxygen
values are much lower, ranging from an April minimum of 2.5 to 3.0 ml/1 to a
high in December of 4.0 ml/1. At 200 m (656 ft), dissolved oxygen
concentrations below 2.0 ml/1 have been recorded between February and
August.
Borderland Basin--
CalCOFI Station 90.45 which is in 900 m (2,953 ft) of water is
representative of basin disposal locations within the California Bight.
334
-------
N30
20
10
co
i.
£ S-10
o
3 N10
>
AVG. VELOCITY = 9.9 CM/SEC
VARIANCE = 7.1 CM/SEC
23 MAR
24 MAR
25 MAR
AVG. VELOCITY = 5.6 CM/SEC
VARIANCE = 3.8 CM/SEC
-10
S-20
16 MAR
17 MAR
18 MAR
REFERENCE: Hendricks, 1980.
Figure 68. Alongshore current at 40-m depth (55-m water
depth) off Point Loma, March, 1975, showing
considerably different flow conditions only a
week apart.
335
-------
1.0
LL
O
£ 0.5
_j
m
<
CD
O
tr
o.
0.0
10
Shelf——— (40/55 m)
1 4/16- 5/17/79
211/22-12/20/78
3 8/ 3 - 9/5/78
Canyon — — — — —
1 9/29 -10/13/77 (60/170 m)
2 9/29-10/13/77 (167/170 m)
3 9/12 - 10/ 4/74 (369/370 m)
Shelf Bottom
2/6 - 31 6/78 (54/55 m)
Slope
20
vr (cm/sec)
5/8 -, 6/12/78 (430/475 m)
I
30
40
REFERENCE: Hendricks. I960.
Figure 69.
Distribution of current speeds
canyon, slope, and near-bottom.
- southern California
336
-------
IT JFUAUJJISONOJ JFM4MJJ1SONOJ
£ MEAN TEMPERATURE (°C) MEAN SALINITY (ppl)
LLJ 0 | , 0 ,
Q
200
JFMiMJJiSONDJ JFMAMJJiSONOJ
MEAN DISSOLVED OXYGEN (ml/1) MEAN DENSITY (ot)
NOTE: 1ml/l = 1.428 mg/1
REFERENCE: CALCOFI Atlas No. 25
Figure 70. Annual temperature, salinity, dissolved oxygen,
and density distributions in the upper 200 m
at CalCOFI Station 90.28.
337
-------
Annual variations in the mean temperature, salinity, density, and dissolved
oxygen expected at such a site are presented in Figure 71.
Surface temperatures typically range from 19°C in August to as low as
14.5°C in January. A pronounced spring thermocline forms at 10 to 20 m (33
to 66 ft) as at shelf stations, and tends to persist through October. The
salinity distribution in contrast is relatively uniform in the upper 50 m
(164 ft), increasing somewhat beyond the 100 m (328 ft) depth. The
characteristic density profile exhibits a strong density gradient associated
with ambient temperature, following the same pattern as temperature but in
reverse magnitude. A very strong density gradient forms in the spring,
becomes maximum [sigma-t difference is 1.0 from 10 to 30 m (33 to 98 ft)
depths] in the summer and dissipates in the fall. Dissolved oxygen values
are a maximum near the surface (7.8 mg/1), decrease with depth, and are
relatively constant in the upper 50 m (164 ft) throughout the year. At 100
m (328 ft) and greater depths, a relatively pronounced DO minimum occurs
during June, gradually returning to maximum values in December and January.
Concentrations below 2.1 mg/1 have been recorded at depths beyond 300 m (984
ft) as indicated in Figure 72.
Dynamic topography contours for surface geostrophic flows relative to
flows at 500 m (1,640 ft) (Wyllie 1966) for a mid-Bight location such as
Station 90.45 indicate south to southeast flows for February through June,
with northerly flows from July to January. Flows at a 200 m (656 ft) depth
relative to those at 500 m (1,640 ft) appear to be northward throughout the
year except during March and April, when calculated flows become very low.
Although monthly mean charts serve only as a guideline, the trend of the
southward-flowing California Current moving inshore during April-May and
eliminating the Southern California Counter Current at the surface is
evident, and may happen briefly even at the 200 m (656 ft) level. Outside
of this period, however, flows can be expected to be northward. Dynamic
topography charts indicate approximate current speeds of from 0 to 10 cm/sec
at the surface, and less than 5 cm/sec at 200 m (656 ft).
Deep Ocean—
The typical physical oceanographic conditions which exist at deep-ocean
areas off the California Bight are presented in Figure 73 for CalCOFI
Station 90.70. Surface temperatures vary from 17°C between August and
October to a low of 14.5°C between January and June. At 100 m (328 ft) the
temperature variation is slight, remaining at approximately 10.5°C.
Although a thermocline is present, it is far less pronounced than for
nearshore stations. Surface salinity concentrations vary little, remaining
at 33.4 ppt. An increase of 0.1 ppt is apparent at depths of 100 to 200 m
(328 to 656 ft) in October and November. The density profiles appear to
follow the water temperature pattern in the upper 50 m (164 ft), and seem to
be dependent primarily on salinity variations in waters beyond this depth.
The maximum density gradient occurs in September and October. Seasonal
density variation at depths below 50 m (164 ft) is small, amounting to
approximately 0.2 sigma-t units or less. Dissolved oxygen in the surface
waters remains seasonally constant at 7.8 mg/1 and decreases approximately
2.9 mg/1 per 100 m (328 ft) of depth from 50 to 200 m (164 to 656 ft)
338
-------
E 200
JFWiMJJiSONDj
MEAN SALINITY (ppt)
MEAN TEMPERATURE (°C)
JFU4MJJ4SONOJ JFMiMJJiSOMOj
MEAN DISSOLVED OXYGEN (ml/1)
NOTE 1ml/l = 1.428 mg/l
MEAN DENSITY (ot)
REFERENCE: CALCOFI Atlas No. 25
Figure 71. Annual temperature, salinity, dissolved oxygen,
and density distributions in the upper 200 m
at CalCOFI Station 90.45.
339
-------
OFFSHORE
in N-CMOO
STATION
300
MEAN TEMPERATURE (CC)
MEAN SALINITY (ppt)
STATION
MEAN DISSOLVED OXYGEN (ml/I)
REFERENCE: Wyllie and Lynn, 1971
Figure 72. Representative Line 90 vertical sections for
temperature, salinity, and dissolved oxygen.
340
-------
/.31.0
ISO .
•=•200 _ _
•=• JFMiMJJiSONOJ JFUJUJJtSOHDJ
jE MEAN TEMPERATURE ("C) MEAN SALINITY (ppt)
o.—,—,—,—, . , , . ,— , o
jfMAUJJiSONDJ JFUtWJJASONDJ
MEAN DISSOLVED OXYGEN (ml/1) MEAN DENSITY (ot)
NOTE: 1ml/l = 1.428 mg/l
REFERENCE: CALCOFI Atlas No. 25
Figure 73. Annual temperature, salinity, dissolved oxygen,
and density distributions in the upper 200 m
at CalCOFI Station 90.70.
341
-------
There is evidence of slight maxima in May and minima in November. However,
the annual range at a given depth is approximately only 1.4 mg/1 beyond 75 m
(246 ft) deep. At 200 m (656 ft), a value of 3.6 mg/1 has been reported.
As indicated in Figure 21, values as low as 2.1 mg/1 occur at depths beyond
300 m (984 ft). Calculated geostrophic flows at the surface relative to a
500 m (1,640 ft) depth appear to be between 2 and 15 cm/year to the
southwest throughout the year. Maximum currents probably occur in the
June/July and November/December periods (Wyllie 1966). At 200 m (656 ft)
relative to 500 m (1,640 ft) currents, the flows appear to be much weaker,
being between 0 and 3 to 4 cm/sec. For much of the year (e.g., August to
December) the flow pattern appears to be poorly defined.
Biological Characteristics
Open Ocean Environments off Southern California--
In open ocean environments beyond the continental slope offshore from
southern California, virtually all primary production is performed_by
phytoplankton. Due to its dependence on sunlight, phytoplankton production
is limited to the upper (< 100 m) sunlit layers of the ocean in this region.
All other life in these environments is dependent on the fixation of carbon
by phytoplankton, and hence production by the phytoplankton is essential to
all higher trophic levels.
Phytoplankton production in waters of the California Current is
apparently not nutrient limited, in spite of strong thermal stratification
of the water column and low nitrate concentrations within the euphotic zone
(Malone 1971). Nanoplankton (phytoplankton with cells < 22 urn in diameter)
accounted for 75 to 99 percent of the observed productivity and standing
stock in waters of the California Current, and this fraction was remarkably
stable geographically (Malone 1971).
In summer, a subsurface chlorophyll maximum is typically found near the
base of the euphotic zone, at approximately 100 m depth (Malone 1971). This
maximum is primarily due to increases in the nanoplankton fraction, while
chlorophyll contained within the netplankton fraction (cells > 22 urn in
diameter) was relatively uniformly distributed with depth within the
euphotic zone (Malone 1971). The position of the subsurface chlorophyll
maximum was generally closely associated with the nitrate nutricline, and
the shoaling of the chlorophyll maximum at stations nearer the California
coast paralleled the upward trend of the isotherms and nitrate isopleths
(Malone 1971).
In winter, the subsurface chlorophyll maximum is still present, but at
considerably shallower depth (approximately 30 m; cf. Malone 1971). The
depths of this maximum was again closely associated with the nitrate
nutricline.
The fact that phytoplankton production in California Current waters
does not appear to be nutrient limited is likely related to the predominance
of nanoplankton over netplankton. Nanoplankton typically have lower
half-saturation constants for nitrate uptake (Maclssac and Dugdale 1969-
342
-------
Eppley et al., 1969), and are therefore able to photosynthesize at higher
rates under low nitrate concentrations than can netplankton. In addition,
it seems likely that animals grazing on nanoplankton are smaller (e.g.,
protozoans; cf. Beers and Stewart 1969) than those grazing on netplankton.
As a consequence of the short generation times of these small grazers, the
coupling between primary productivity and grazing would be much closer for
nanoplankton-based food chains than for netplankton-based food chains, and
there would be less opportunity for unrestricted growth followed by nutrient
limitation (Malone 1971). Overall phytoplankton production is low in the
offshore waters of the California Current relative to that in nearshore
waters over the continental shelf and the continental slope, where
phytoplankton production is enhanced in spring and summer by coastal
upwelling (Malone 1971).
Malone (1971) described the nanoplankton fraction of the phytoplankton
as being dominated by flagellates, and cited the more detailed observations
of Reid et al. (1970) which indicated that the nanoplankton were likely
composed primarily of naked dinoflagellates, "monads," and coccolithophores.
The netplankton fraction, although a relatively minor portion of the
phytoplankton community, was composed almost exclusively of diatoms (Malone
1971).
Zooplankton inhabiting oceanic waters off southern California include
species having a variety of faunistic affinities. Investigations of
zooplankton communities in the California Current off Baja California
(Longhurst 1967) revealed that species characteristic of Pacific
Transitional Water, Central Pacific Water, and Tropical Surface Water were
all present on occasion. The species characteristic of Pacific Transitional
Water are obviously transported into the area by the southward flow of the
California Current, while the tropical species are sometimes advected by
occasional northward movements of tropical water masses. The Central
Pacific Water species are those inhabiting oceanic waters beyond the
California Current. Small calanoid copepods (e.g., Paracalanus sp.,
Pseudocalanus sp.) and cyclopoid copepods (e.g., Oithona simi_1i_s') are
abundant near the surface in oceanic waters off southern California. Arthur
(1977) found that the small calanoid copepod, Mecynocera clausii, could be
used as an indicator of offshore water masses in this area, as it was not
found inshore. Copepod nauplii are particularly abundant in the California
Current, and concentrations of these nauplii are important for the
successful feeding of many larval fishes (Arthur 1977).
While small calanoid copepods predominate in the euphotic zone, deeper
layers are inhabited by larger copepods, euphausiids, and other zooplankton
species, some of which perform diel vertical migrations which bring them
into the euphotic zone only at night. Zooplankton occur at all depths
throughout the water column in the region offshore of southern California,
but those occurring below about 200 m are almost exclusively carnivores
and/or detritivores.
Common epipelagic fishes of the California Current include sardines
(Sardinops sagax), anchovies (Engraulis mordax), jack mackerel (Trachurus
symmetricusj, sauries (Cololabis sal raj, and albacore (Thunnus alalunga).
343
-------
Marine mammals of this area include various whale and porpoise species
(cf. Dailey 1974). The larger nekton species are generally strong swimmers
which range over large areas of the oceans and are not restricted to a
single geographic area. Because these large species of nekton are a number
of trophic levels removed from the primary producers, they are quite rare
considering the total expanse of the oceans. Nevertheless, certain species
(e.g., whales, porpoises, albacore) are known to school, and consequently
they may be abundant in a given area for a short period of time.
A number of small nektonic species in the California Current region
inhabit mesopelagic depths (100-1,000 m) and some of these perform die!
vertical migrations into the epipelagic zone (< 100 m) [cf. Wisner 1976].
While these species are widespread, individuals of these species are not as
wide-ranging as those of the larger, epipelagic species.
Most pelagic fish species in waters offshore of southern California lay
and fertilize their eggs in the sea itself. The eggs and larvae,
collectively referred to as ichthyoplankton, are carried about by the
currents. The larvae are typically very small, and dependent on plankton
for food (Arthur 1976). The spawning strategies of many of these fishes are
dependent on surface drift conditions, and food limitation during critical
larval stages of these fishes may regulate their reproductive success
(Parrish et al., 1981).
While little specific information is available on deep benthic
communities off southern California, it seems likely that the benthic
organisms there are similar to" those in the other deep oceans of the world.
The discussion of benthic animals presented in the Gulf of Mexico section is
applicable to southern California.
Oceanic Environments of the Continental Borderland off Southern California--
The complex topography of the sea floor off southern California renders
this area relatively unique and has important implications for the
biological communities inhabiting the area. The basins, ridges, banks, and
islands of the continental borderland encompass attributes of both the
deepwater environments farther offshore and the nearshore environments
inshore of the borderland.
The standing stock of phytoplankton, as indicated by chlorophyll a,
exhibits a typical onshore-offshore gradient in the southern California
Bight. Eppley et al. (1978) reported that average concentrations of
chlorophyll a within the euphotic zone were generally < 1 mg m~3, except at
stations witTFin 3 km of the coast, where concentrations sometimes exceeded
10 mg m~J. These gradients were persistent and not seasonal when based on
stocks per mj, but the gradients were not so apparent when stocks were
expressed per m*. The latter fact is expected because the depth of the
euphotic zone increases as one moves offshore (Eppley et al., 1978).
Phytoplankton production is apparently limited, except during periods of
coastal upwelling, by the availability of fixed nitrogen, primarily as
nitrate. The abundance of phytoplankton was inversely related to the depth
of the nitrate nutricline (i.e., phytopl ankton was most abundant when the
344
-------
nitrate nutricline was shallowest; Eppley et al., 1978). The depth of the
subsurface chlorophyll maximum was closely associated with the depth of the
nutricline, and not with a given light level (Eppley et al., 1978). In the
offshore waters (> 100 m depth), the depth of the nutricline is influenced
by variations in wind speed and direction, with maximum wind-induced
upwelling during June (Eppley et al., 1978).
Small flagellates are the dominant phytoplankton in this area, although
dinoflagellates and diatoms are also abundant (Reid et al., 1978). Diatoms
may become more abundant during periods of coastal upwelling (Malone 1971).
As for the zooplankton farther offshore, the zooplankton inhabiting
waters over the continental borderland of southern California represent a
transitional fauna which may include representatives of subarctic Pacific
waters to the north, Central Pacific waters to the west, and Equatorial
Pacific waters to the south, as well as species endemic to the area (Seapy
1974). Abundant calanoid copepods include Cal anus paci ficus (=
helgolandicus), Rhincalanus nasutus, and Labidocera tnspinosa (McGinnis
1971), whi1 e Oithona simiTi s is the dominant cyclopoid copepod. While many
zooplankton species inhabit the euphotic zone, others perform limited (< 200
m) die! vertical migrations which bring them into the euphotic zone only at
night. Zooplankton occur at all depths throughout the water column in this
area, but those occurring below 200 m are almost exclusively carnivores
and/or detritivores.
The epipelagic fishes common to the California Current are also
abundant over the continental borderland. Included are sardines, anchovies,
jack mackerel, sauries, and albacore. Notable among the marine mammals
frequenting the area are the California gray whales (Eschrichtius robustus),
which annually migrate between feeding grounds in the Bering Sea and
breeding grounds off Baja California.
The deep basins of the California borderland have a resident
mesopelagic fish fauna (Ebeling et al., 1971). Many of the mesopelagic
fishes make diel vertical migrations into the epipelagic zone where they
feed on zooplankton (Anderson 1967).
The California borderland represents a variety of benthic habitats
because of the large variations in depth and distance from shore.
Shallow-water subtidal habitats may be found as far as 180 km from shore
(e.g., Cortes and Tanner Banks; cf. Lewbel et al., 1981), while relatively
deep basins (depths in excess of 800 m) may be found within 5 km of shore
(e.g., Santa Monica and San Pedro Basins; cf. Jackson et al., 1979).
Shallow-water benthic communities of the California borderland share
many species with the shallow-water benthic communities nearshore, to be
described below. Lewbel et al. (1981) reported, for instance that the
benthic fauna of Cortes and Tanner Banks could be subdivided into two
communities: a shallow (< 25 m) community dominated by the southern sea
palm (Eisenia arborea), and a deeper (> 30 m) community characterized by
encrusting red coralline algae (Li thophyl1 urn proboscideum). Relative
species abundances differed from those at comparable depths near the
345
-------
mainland, however, and there were species notably absent (e.g., the giant
kelp, Macrocystis pyrifera).
The benthic infauna on the sea floor of the California borderland
exhibit depth-related trends to be expected in any marine benthic habitat.
Benthic infaunal abundance, biomass, and number of species all decrease with
increasing depth (Mearns et al., 1979). One complicating factor, however,
is that the dissolved oxygen concentration in the deep basins may be
depressed (< 0.3 mg/1 ) due to reduced water exchange and organic matter
decay in the basins (Jackson et al., 1979). The benthic fauna in these
basins is consequently depauperate relative to the fauna at similar depths
where oxygen concentrations are higher (Mearns et al., 1979). Invertebrates
present include polychaetes, arthropods, echinoderms, mollusks, and
coelenterates (Mearns et al., 1979). Basins on the outer shelf have
distinctly different faunas than those of the nearshore basins (Hartman and
Barnard 1958, 1960). Their faunas are more similar to the continental slope
and shallow bottom faunas of the North Pacific (SCCWRP 1973).
Within the basins of the continental borderland is found a diverse
demersal fish fauna. Common representatives include longspine thornyhead
(Sebastolobus altivelis), California rattail (Nezumia stelgidolepis),
shortsplne thornyhead (Sebastolobus alascanus), sablefish (Anoplopoma
fimbria) and brown cat sharks (Apisturus brunneus) (Mearns et al., 1979).
The peak biomass of bottom fishes occurs between 200 and 400 m, while fish
diversity remains relatively unchanged from 20 to 610 m (Mearns et al.,
1979).
Nearshore Environments of Southern California—
The coastline of southern California includes both rocky headlands and
sandy beaches, but relatively few estuan'ne embayments (e.g., San Diego Bay,
Newport Bay). Only the open ocean environments (exclusive of the
embayments) will be discussed below. Each represents a unique habitat for
marine organisms.
Nearshore phytopl ankton communities exhibit a continuation of those
trends noted above for phytoplankton further offshore (e.g.,
onshore-offshore gradients of phytoplankton standing stock and primary
productivity, with the highest values of each occurring nearshore). Whereas
average concentrations of chlorophyll _a within the euphotic zone are
typically low offshore (< 1 mg m"3), within 3 km of the coast concentrations
sometimes exceed 10 mg m'J (Eppley et al., 1978). Although the depth of the
euphotic zone increases with increasing distance offshore (Eppley et al.,
1978), integrated primary productivity is still highest near shore
[Institute of Marine Resources (1971) and Thomas (1972) report values of
2,460 mg C m"^ day'1 and 1,972 mg C m'2 day1 for nearshore stations over
Scripps Canyon and off Camp Pendleton, respectively]. Eppley et al. (1978)
demonstrated that the increase in phytoplankton stocks with approach to the
shore at depths < 100 m is consistent with Riley's (1967) model which
attributes this effect to the increases in vertical eddy diffusivity
associated with increased tidal action nearshore.
346
-------
As in waters farther offshore, phytoplankton production nearshore is
apparently limited, except during periods of coastal upwelling, by the
availability of fixed nitrogen, primarily as nitrate (Eppley et al., 1978).
Phytoplankton production nearshore may be enhanced by tidal action, internal
waves (cf. Kamykowski 1973), and coastal upwelling (Eppley et al., 1978).
There is typically a subsurface chlorophyll maximum at depths
corresponding to 3-30 percent of surface irradiance, except during periods
of strong upwelling (Reid et al., 1978). The subsurface chlorophyll maximum
layer is typically found in the thermocline and in the upper portion of the
nutricline (Reid et al., 1978). Phytoplankton species within the
chlorophyll maximum layer change more abruptly with distance offshore than
alongshore, and give the impression of elongate bands of phytoplankton
oriented parallel to shore (Reid et al., 1978).
As for the zooplankton farther offshore, the zooplankton inhabiting
neritic waters of southern California represent a transitional fauna which
may include representatives of Subarctic Pacific waters to the north,
Central Pacific waters .to the west, and Equatorial Pacific waters to the
south, as well as species endemic to the area (Seapy 1974). While many
zooplankton species inhabit the euphotic zone, others perform die! vertical
migrations which bring them into the euphotic zone only at night. Koslow
and Ota (1981) have shown how the presence of nearshore submarine canyons
serves to concentrate migratory zooplankton species descending into them.
Abundant pelagic fishes of the southern California nearshore zone
include the aforementioned anchovies, sardines, and jack mackerel. The
spawning of many of the pelagic fishes of this area is closely linked to the
prevailing current regimes (Parrish et al., 1981). Food limitation during
critical larval stages may regulate reproductive success. Lasker (1975,
1978) has shown that successful feeding of early anchovy larvae is dependent
on concentrations of phytoplankton within chlorophyll maximum layers. Such
concentrations persist only in the absence of storm-driven turbulence or
strong upwelling. Sardines and jack mackerel spawn during the period of
maximum upwelling, and their larvae feed almost exclusively on the early
stages of copepods (Arthur 1976). The abundance of copepods is largely
dependent on upwelling-related meteorological conditions prior to and during
the spawning periods, because upwelling causes increases in primary
productivity and results in copepod reproduction (Parrish et al., 1981).
Hence, conditions favoring larval survival are quite different for anchovies
than for sardines or jack mackerel. Similar relationships are likely to
exist for other pelagic species of the southern California nearshore zone.
Certain marine mammals [notably sea otters (Enhydra lutris] were once
common in nearshore southern California waters, but now are quite rare
(Dailey 1974). Resident populations of some pinnipeds [e.g., California sea
lion (Zalophus californianus), Stellar sea lion (Eumetopias jubatus),
northern elephant seal (Mirounga angustirpstris)] are found on some of the
offshore islands (Dailey 1974).The California gray whale is the only
baleen whale commonly observed within several kilometers of the southern
California coast. Several porpoise and dolphin species are abundant in the
area and may enter nearshore waters (Dailey 1974).
347
-------
Rocky shorelines of southern California provide hard substrate for the
attachment of benthic algae and many sessile animal species. In certain
areas where benthic algae are particularly abundant (e.g., kelp beds), a
significant portion of the community primary production may be attributed to
these benthic macrophytes. The communities inhabiting these rocky
shorelines are complex assemblages of organisms which include
representatives of many of those types common on rocky shorelines worldwide
[e.g., starfish, limpets, chitons, barnacles, sea urchins, sea anemones,
brown and red algae, etc.; cf. Bright (1974)]. In certain areas where there
is adequate rocky subtidal habitat, kelp [notably giant kelp (Macrocystis
pyrifera)] grows in large quantities and is harvested commercial ly
(cf. Wilson et al., 1978).
Shallow sandy subtidal and sandy intertidal areas of southern
California are inhabitated primarily by organisms which burrow into the
substrate for protection from wave action and sediment scour (Bright 1974).
Sand-bottom areas are subject to considerable seasonal and year-to-year
variation, and hence the abundance of organisms at any given location
undergoes substantial fluctuations.
A relatively unique feature of nearshore environments in southern
California is the presence of submarine canyons which extend from the
coastline to deep basins and troughs offshore (SCCWRP 1973). These
submarine canyons serve as conduits for the transport of sedimentary
material into the deeper waters offshore, and may be considered for the
disposal of manganese nodule processing wastes. These canyons contain a
unique and varied fauna. Hartman (1963) found that 30-60 percent of the
species found in one canyon were not found in adjacent canyons, indicating
some degree of isolation (Fay 1972). The indigenous fauna in these canyons
must be adapted to widely varying environmental conditions (e.g., shoreward
movement of upwelling waters, seaward transport of sedimentary material)
which can change quite rapidly (SCCWRP 1973). In general, the diversity and
abundance of animals decrease with depth within the canyons, and the benthic
biomass there is intermediate between that on the shelf and in the deeper
basins of the continental borderland.
Southern California Fisheries--
The fisheries considered in this section occur in the Southern
California Bight, an area of about 41,000 to 51,000 km2, which is bounded to
the north by Point Conception and to the south by Point Descanso, Mexico
(Mais 1974). Major commercial fisheries conducted in the bight focus on
pelagic species such as tuna (Thunnus spp., Euthynnus spp.) and schooling
fishes [e.g., northern anchovy fEngraulis mordax), jack mackerel (Trachurus
symmetricus)] which are caught with purse seines, gill nets, and
hook-and-line gear. The continental shelf is extremely narrow, ranging from
1 to 23 km in width, with the wider areas found in the northern portion of
the bight. Because of the limited shelf area and some regulatory
limitations, trawl fisheries are not as important in Southern California as
in areas to the north (Leet and Cramer 1971).
348
-------
The main fishing ports in Southern California are Santa Barbara, San
Pedro, and San Diego (Leet and Cramer 1971). The latter two areas were the
leading U.S. ports in terms of landing values in 1980; $121.9 million for
San Pedro, $110.6 million for San Diego. Combined landings at San Pedro and
San Diego exceeded 262 million kg in 1980 (National Marine Fisheries Service
1981).
Pishing Areas—The tuna fisheries are the most important in Southern
California. The main species which support the tuna industry are yellowfin
(Thunnus albacares) and skipjack (Euthynnus pelamis), which are taken off
the coasts of Central and South America (Frey 1971). The local fisheries
for albacore (Thunnus alalunga) and bluefin (Thunnus thynnus) depend upon
these species migrating into the bight.
The albacore fishery is generally conducted 80 to 124 km offshore,
beginning in June by trollers and bait boats (Browning 1980). Albacore
arrive when offshore water temperatures range between 15.5 and 20° C, and
then they continue northward up the coast following the warm water (Frey
1971). Poor year-class strength drastically affects the fishery because 1
and 2 year old fish are the primary age classes taken in the fishery.
Bluefin tuna occurring in the bight are landed by the local purse seine
fleet, which also participates in the oil and meal reduction fishery.
Bluefin tuna are taken between Baja California and Point Conception during
July and August (Frey 1971). The highseas fleet accounts for about 95
percent of the catch of this species.
Pacific bonito (Sarda chiliensis) are primarily taken incidental to the
troll and purse seine fisheries for tuna. Bonito's chief importance in
Southern California is to the recreational fishery (Frey 1971).
The oil and meal reduction fishery targets primarily on northern
anchovy and to a lesser extent on jack mackerel, Pacific mackerel (Scomber
japonicus), bonito, bluefin tuna, and squid (Loligp spp.) (PFMC 1978a). The
Pacific sardine (Sardinops sagaxj and Pacific mackerel were the traditional
species supporting the fishery, but these stocks are now extremely depleted
(MacCall et al., 1976). Recently, there are indications that Pacific
mackerel abundance may be increasing (Klingbeil et al., 1980).
The central anchovy subpopul ation is the most abundant of the three
west coast stocks. The bulk of the population occurs in the Southern
California Bight (PFMC 1978a). The oil and meal reduction fishery is
centered in the channel region extending from Santa Barbara - Santa Cruz
Island to Santa Catalina Island - Dana Point, an area of approximately 6,800
km2 (PFMC 1978a).
The Southern California reduction fishing fleet consists of
approximately 25 vessels fishing in the Catalina and Santa Barbara channels
(PFMC 1978a). In addition to the reduction fishery, a small live bait
industry also harvests anchovies in Southern California. The average annual
value of these two fisheries during 1970-1975 amounted to $3.3 million, of
which 98 percent was attributed to the reduction fishery (PFMC 1978a).
349
-------
Over 90 percent of the catch of jack mackerel, the second major species
supporting the reduction fishery, is taken in the vicinity of Santa Catalina
and San Clemente Islands and on Cortes Bank (Mais 1974).
The market squid (Loligo opalescens) is the major squid species taken
in Southern California. fhlTfishery occurs within 4.8 km of shore along the
mainland coast and around the channel islands (PFMC 1978b). This fishery
begins in December and continues until the squid move northward in spring.
Typically, fishermen search the edge of kelp beds for schools of spawning
squid. The fishery occurs in depths ranging from 35 to 55 m (PFMC 1978b).
Two types of methods are used to harvest squid; purse seines in deeper water
areas and a light attraction technique in waters of 24 to 33 m. Average
annual landings in California during 1970-1977 were 10,237,580 kg (PFMC
1978b). A large portion of this total was caught in Monterey Bay, however,
and not in Southern California. California accounts for 76 percent of the
nation's squid catch, which had an average exvessel value during 1970-1976
of $1.4 million (PFMC 1978b). Squid are the most important underutilized
species in Southern California, although effort is increasing in the fishery
(Mais 1974). Fifty vessels fished squid in 1970, but by 1974, 126 boats
participated in the fishery (PFMC 1978b).
The groundfish species of Southern California are of secondary
importance in comparison to pelagic fishes. Regulations and the narrow
shelf area of the bight confine trawling to the Santa Barbara Channel (Frey
1971). Depending on the target species, trawls are fished from 4.8 km
offshore to depths of 457 m (PFMC 1980). Rockfishes (Sebastes spp.) and
flatfish such as California halibut (Pa ra1i chthys ca1 i forni cus), English
sole (Parophrys vetulus), petrale sole (Eopsetta jordan"i") and rex sole
(Glyptocephalus zachirus) are the major species exploited (Frey 1971; PFMC
1980). Minor quantities of lingcod (0 p h i o d on e1o n g a t u s) and sablefish
(Anoplopoma fimbria) are also taken by trawls!! Trawl landings during
1975-1979 averaged 2,696 mt in the International North Pacific Fisheries
Commission Conception statistical area which includes the bight (PFMC 1980).
California groundfish landings in 1976 were valued at over $11 million (PFMC
1980).
In areas south of Oxnard, trammel nets are usually fished close to
shore in shallow water. The primary catch is California halibut, with
incidental catches of petrale sole, rex sole, and various rockfishes (Frey
1971).
The rockfish fishery in Southern California is primarily conducted with
gill nets and hook-and-1ine gear (Frey 1971; PFMC 1980). Bocaccio (Sebastes
paucispinis), chili pepper (_S. goodei). olive rockfish (_S. serranoides), and
yellowtail rockfish (_S. flavidus) are the main species taken (PFMC 1980).
Olive rockfish school at depths ranging from 15 to 46 m and are harvested in
the vicinity of kelp beds south of Point Conception and also around offshore
islands such as Santa Barbara and San Nicolas (Frey 1971).
A pot fishery for sablefish has been rapidly developing since 1978 in
Southern California. Landings during 1975-1977 were less than 1,000 mt but
by 1979 over 4,000 mt were landed (PFMC 1980).
350
-------
Miscellaneous fisheries conducted in the bight include those for
swordfish (Xiphias gladius), California barracuda (Sphyraena argentea),
white seabass (Atractoscion nobilis), white croaker (Genyonemus nneatus),
and surfperches (embiotocidsj^The latter four are generally more important
to recreational fisheries than to the commercial industry.
The specialized harpoon swordfish fishery is centered in the channel
islands Basin between Point Conception and San Diego (Frey 1971). Major
fishing areas are associated with islands, banks, mouths of submarine
canyons, and at steep submarine ridges. There is also a small-scale
longline fishery for swordfish conducted at the edge of the continental
shelf between Cedros Island and Cape San Lucas, Baja California (Frey 1971).
California barracuda are taken with hook-and-line troll gear and gill
nets. The fishery occurs primarily during May and June in the vicinity of
San Pedro, Santa Barbara, and San Diego in relatively shallow (36m) shelf
waters (Frey 1971). Currently, stocks of barracuda appear to be depleted
(MacCall et al., 1976).
White seabass are also fished using gillnets and hook-and-line gear in
the coastal waters of the bight (Frey 1971). This is a small fishery with
approximately 15 vessels participating (PFMC 1980). MacCall et al. (1976)
reported that the stock was already moderately to highly exploited.
The white croaker fishery employs small round nets to harvest this
schooling species in inshore areas ranging in depth from 3 to 30 m (Frey
1971).
The two important shell fisheries in Southern California are for spiny
lobster (Panulirus interruptus) and abalone (Haliotis spp.). All rocky
coastal areas from Point Conception to the U.S.-Mexican border, as well as
the islands and banks of the bight, are important fishing areas for lobster
(Frey 1971). Most pots are set at depths of less than 18 m; however, in
some areas pots are set at depths to 64 m (Frey 1971). In 1969, a total of
nearly 140,000 kg of lobster was landed with a value of $300,000 (Frey
1971).
The abalone fishery is centered in the vicinity of kelp beds near the
Channel Islands and Santa Barbara. Red (Haliotis rufescens), pink
(H. corrugata). white (H. sorenseni), and green (H. fulgens) abalone make up
tTfe commercial catch. The fishery is conducted "By divers at depths ranging
from 8 to 24 m and at times extending to 55 m (Frey 1971).
Squid may support expanded fisheries in the future in Southern
California (Mais 1974). Both nearshore and offshore areas appear to be
equally productive for this resource. Also, there is potential for growth
in the reduction fishery for anchovies and jack mackerel if other markets
become established (PFMC 1978a). Similarly, expansion may occur in the
groundfish fisheries if markets and processing facilities are developed for
currently underutilized species such as sharks, skates, and rays.
351
-------
In summary, the most important fisheries in the Southern California
Bight are for pelagic species such as tuna and those exploited by the
reduction fishery. Groundfish fisheries are generally of less importance
because of the limited extent of the continental shelf and some regulatory
limitations. It may not be desirable to dispose of manganese nodule wastes
in the area of existing trawling grounds off Santa Barbara. The highly
mobile nature of the pelagic species and the wide areas over which the
fisheries are conducted make it extremely difficult to predict potential
impacts which may be associated with waste disposal.
Fish Bio1ogy--A1bacore and bluefin tuna are seasonal migrants into the
bight whose abundance is influenced by water temperatures and the
availability of forage species (Frey 1971). The fishery exploits immature
fish, primarily 1 and 2 year olds. In the bight, these tunas feed on
pelagic organisms such as anchovies, squid, and euphausiids.
Northern anchovies spawn during late winter in the upper water layers
south of San Pedro when water temperatures of 10 to 23.3° C occur (PFMC
1978a; Hart 1973). Their pelagic eggs hatch within 2 to 4 days (Hart 1973).
Both eggs and larvae have been encountered as far as 480 km offshore;
however, greatest densities generally occur inshore (Hart 1973; PFMC 1978a).
Anchovy year class strength is directly associated with larval habitat
conditions. Favorable conditions for larvae include dense plankton blooms
of edible and nutritious organisms (PFMC 1978a). Plankton production relies
on upwelling, the timing and extent of which is influenced by wind patterns.
Severe storms which interfere with upwelling conditions are sufficient to
cause poor larval survival.
In the Southern California Bight, anchovies are widely distributed from
shore to 157 km. Greatest abundance is usually within 37 km of shore over
deepwater (> 183 m) basins (PFMC 1978a). Adult fish have been found to
depths of 300 m. The most common schooling behavior for anchovies is the
formation of small, very low density aggregations in near-surface waters
during the day (PFMC 1978a). At night, the schools disperse widely
throughout the surface layer. Longshore anchovy migrations between southern
and central California have been documented, and onshore-offshore movements
are common. Adults tend to remain farthest offshore (PFMC 1978a).
Anchovies have been described as "indiscriminate filter feeders," taking
both zooplankton and phytoplankton (Frey 1971). Small fishes may also
provide a portion of the diet.
Jack mackerel spawning populations occur offshore between Point
Conception and Cape San Quintin with peak spawning during March to July
(Frey 1971). Females may spawn more than once during the season (Frey
1971). Their pelagic eggs hatch in 4 to 5 days. Jack mackerel eggs are
among the most abundant fish eggs collected in Southern California plankton
surveys (Frey 1971). Small juveniles are widely distributed from 9 to 111
km offshore where near-surface schooling occurs over deepwater basins (Mais
1974). Adult jack mackerels school at depths ranging from 9 to 73 m (Mais
1974). Commercial concentrations are found only in very specific locations
with particular types of habitat. Preferred habitats include relatively
shallow (9 to 55 m) rocky banks, rocky perimeters of offshore islands, and
352
-------
rocky coastal areas associated with kelp beds (Mais 1974). Jack mackerel
are known to conduct onshore-offshore migrations. Juveniles move inshore
from the offshore spawning regions, and the adults return to oceanic areas
as they mature (Frey 1971). Coastal migrations between California and Baja
California also occur (Frey 1971). Prey items include copepods, pteropods,
euphausiids, juvenile squid, and anchovies (Frey 1971).
Pacific bonito are a pelagic schooling species inhabiting the waters of
the continental shelf, primarily between Point Conception and Magdalena Bay
in Baja California (Frey 1971). Pelagic eggs, spawned during January to
May, hatch in 3 days (Frey 1971). Little information is available
concerning the migratory patterns of this species. Bonito feed on pelagic
species including sardines, anchovies, and squid (Hart 1973).
In January and February, spawning squid congregate in semi-protected
bays over sand bottoms in Southern California (PFMC 1978b). Fall spawning
is also known to occur during some years. Egg capsules are attached to the
substrate and hatching occurs within 3 to 4 weeks (PFMC 1978b). Squid feed
on small fishes, shrimp, and other squid (Frey 1971). Little information is
available on migratory patterns of squid. General offshore movements occur,
followed by inshore spawning migrations. Squid of all sizes are found
throughout the year in nearshore waters, however (PFMC 1978b).
The biological aspects of groundfish species are discussed in the
section characterizing the Pacific Northwest fisheries. Only the species
which are of particular importance in the Southern California fisheries will
be considered here.
California halibut spawn during February to July in waters ranging in
depth from 5 to 18 m (Frey 1971). Demersal eggs are produced but larval and
post-larval stages are pelagic prior to undergoing metamorphosis and
settling on the bottom. Northern anchovies are the primary forage species
although octopus, white croaker, and queenfish (Seriphus politus) are also
taken (Frey 1971). Based on tagging studies, juvenile halibut do not
undertake extensive migrations although adults may; onshore-offshore
movements are known to occur (Frey 1971).
English sole spawn during October to May in the Santa Barbara Channel
and in Santa Monica Bay (Frey 1971). Both eggs and larvae are pelagic.
Important nursery areas for English sole include protected inshore locations
such as embayments and estuaries. Benthic food items predominate in the
diet and include segmented worms, clams, and small starfish (Frey 1971).
English sole display extensive migrations in California coastal waters (Frey
1971).
Petrale sole spawn in deepwater (274 to 366 m) basins during the winter
months (Frey 1971). Pelagic eggs are produced. Important food items
include euphausiids, shrimp, anchovies, and other small fishes (Frey 1971).
The four principal rockfish species in Southern California are
bocaccio, chilipepper, olive, and yellowtail. These are ovoviviparous
species which produce pelagic larvae. Spawning periods for these species
353
-------
include the months of November through March. Leet and Cramer (1971)
indicate that rockfish larvae are among the most abundant fish larvae in the
California current, exceeded only in quantity by northern anchovy and
Pacific hake (Merluccius productus) larvae. Bocaccio larvae have been
encountered in the upper surface waters as far as 483 km offshore (Frey
1971). Kelp beds in Southern California are critical habitat areas for
juvenile bocaccio, olive rockfish, and yellowtail rockfish (PFMC 1980).
Rockfishes feed on various organisms, including euphausiids,
cephalopods, crabs, and small fishes (Frey 1971). Preferred habitats of
chilipepper and bocaccio are hard, rocky bottoms in depths of 183 to 305 m
(Frey 1971). Olive rockfish inhabit shallower areas to 146 m depth on kelp
beds and rocky reefs (Frey 1971).
Although there is not a directed fishery on hake in the Southern
California Bight, the region is vitally important to the biology of the
species. As previously discussed, a hake fishery is developing off the
Pacific Northwest coast.
During the winter, mature hake congregate for spawning in depths of 183
to 503 m over the California continental slope (Frey 1971). The main
spawning area is between Point Reyes, California, and Magdalena Bay, Baja
California (Frey 1971)'- The pelagic eggs and larvae of hake are widely
distributed and have been found 644 km offshore (Hart 1973; Frey 1971).
Juvenile hake occur in shelf waters, while adults inhabit both shelf and
slope regions. Over the slope and shelf at depths of 36 to 201 m, hake
schools consist of long, narrow bands oriented parallel to depth contours,
from 61 m to 19 km in length and with a width of 0.3 to 3 km (Frey 1971).
Most schools range in thickness from 5 to 18 m (Frey 1971). Generally,
schools remain just above the bottom during daylight hours, and during the
summer rise through the water column and disperse at night (Frey 1971).
These schools may persist for several days or only for a few hours. Hake
feed on various pelagic fishes and zooplankton (Frey 1971). Adult hake
undertake extensive migrations during the spring and summer into the
northeastern Pacific, with movements directed towards shore and into
shallower water. Southward migrations from the Pacific Northwest regions
occur during late fall and winter, with hake moving into the deeper slope
waters for spawning (Frey 1971).
Little specific biological information is available for swordfish, a
wide-ranging pelagic species. Adults are seasonal migrants into the
Southern California Bight. Evidence indicates that swordfish spend
considerable time feeding at depths of 305 m or more (Frey 1971). In the
bight, swordfish feed on northern anchovies, hake, jack mackerel,
rockfishes, and squid.
California barracuda spawn during May to July in Southern California
and may spawn more than once during the season (Frey 1971). Pelagic eggs
are produced. Barracuda school relatively close to shore and migrate
northward along the coast and offshore islands during the summer, and then
reverse direction during the fall (Hart 1973). This species feeds on
pelagic fishes such as northern anchovies and Pacific sardines.
354
-------
Peak spawning occurs during May and June in nearshore areas for white
seabass. Apparently, very specific sites such as off Long Point on the
Palos Verdes Peninsula in Southern California are utilized for spawning
(Frey 1971). Little information is available concerning the developmental
biology of white seabass. The species is primarily a piscivore and also
preys on crabs and squid (Frey 1971).
White croakers spawns in the spring in the nearshore area. White
croakers often swim in loose schools at or near sandy substrates at depths
ranging from 3 to 30 m (Frey 1971). Prey items include fishes, squid,
shrimps, and a number of benthic invertebrates (Hart 1973; Frey 1971).
White croakers which inhabit areas of sewage outfalls in Southern California
have developed physiological abnormalities, including oral papillomas,
exopthalmia (bulging eyes), and deformed skeletons (Frey 1971).
Lobsters mate during January to April and berried females occur in
shallow (< 9 m) inshore waters (Frey 1971). Eggs hatch in approximately 10
weeks, the phyllosoma larvae undergo 12 molt stages to the final puerulus
stage; i.e., the stage at which the larvae resemble adults (Frey 1971).
Specific spawning areas have not been documented but are believed to be
throughout the range of the adults (i.e., rocky coastal regions). Food
items include snails, sea urchins, sponges, and rock scallops (Frey 1971).
Female lobsters move inshore in March and April, followed by the males in
May. Both sexes apparently migrate offshore in October (Frey 1971).
Abalone begin spawning in spring and continue through summer and fall.
Spawning is triggered by rising water temperatures and chemical stimuli may
also play a role (Frey 1971). Pelagic larvae are produced which feed on
phytoplankton. After 1 to 2 weeks, the larvae settle in rocky areas and
begin grazing on diatoms and coralline algae (Frey 1971). As abalone
mature, larger macrophytes are included in the diet. The kelps, Nereocystis
luetkeana and Macrocystis spp., are the main foods of adult abalone (Frey
1971).
Summary—Pelagic fishes support the major fisheries of the Southern
California Bight. Because of their wide-ranging habits and distribution in
the water column it is difficult to predict the potential impacts which may
be associated with manganese nodule processing waste disposal. The water
column effects of the wastes will probably be the most significant
consideration for pelagic species. For example, it will be important to
evaluate the potential toxicity of the waste material, the residence time of
the wastes in the water column, their particle size, and other
characteristics. Increasing water turbidity may interfere with the
schooling behavior of important fish species (e.g., northern anchovies, jack
mackerel, bonito). Turbidity could also alter plankton production, which
could result in poor survival of northern anchovy larvae and thus alter
population abundance.
The pelagic eggs and larvae of other pelagic species, as well as those
of groundfishes (e.g., English sole, petrale sole), may also be vulnerable
to the water column effects of reject wastes. Hake are of particular
355
-------
concern in this regard since the main slope spawning area is located at the
seaward boundary of the bight.
The demersal eggs of squid and California halibut may be susceptible to
the depositional effects of the waste materials. Adults may also be
affected if the wastes contain potentially toxic substances. Both Dover
sole (Microstomus pacificus) and white croaker which inhabit sewage outfall
areas in Southern California have developed physiological abnormalities
which may be related to sediment contamination.
Waste disposal impacts on critical habitats should also be considered.
For example, rocky substrates associated with kelp beds are important for
jack mackerel, rockfishes, and abalone.
In summary, it is difficult to predict the magnitude of waste disposal
impacts on the fishery resources of the Southern California Bight. However,
potential disposal sites should be evaluated in terms of biological
importance to the species which support the fisheries of the region.
PACIFIC NORTHWEST REGION
Physical Characteristics
Bathymetry—
The northwest offshore region described in this section extends from
Cape Mendocino in northern California to Cape Flattery in Washington (Figure
74). Major physiographic provinces include a continental terrace consisting
of the shelf and slope, the Cascadia Basin, and "a province of irregular
topography on the western flank of the basin" (McManus 1964). The Cascadia
Basin can be further divided into eastern and western portions on the basis
of the Vancouver Valley and southern trend of the Cascadia Seachannel (Gross
1965). A major bathymetric feature, the Mendocino Ridge-Gorda Escarpment
strikes east-west into the continental margin and separates it from northern
California. The major fracture zone marks a regional seafloor change, to
the south of which floor depths are several hundred meters deeper than to
the north.
Continental Shelf--The continental shelf in this northwestern region is
generally narrower, steeper, and has greater depths than average values for
other continental shelves of the world (Shepard 1963). From Cape Mendocino
northward, the shelf tends to widen, from 30 km (16 nmi) on the average in
California to 40 km (22 nmi) off Oregon and 50 km (27 nmi) off Washington.
Widest regions of the shelf of approximately 65 km (35 nmi) occur in the
Heceta Bank area off of central Oregon and at the mouth of the Columbia
River. The narrowest segment which is less than 10 km (5.4 nmi) wide,
occurs off Cape Mendocino. The outer shelf edge occurs at approximately 145
m (475 ft) off Washington and increases in depth going southward to 165 m
(541 ft) off central Oregon and 185 m (607 ft) off northern California. The
shelf break is most pronounced off central Oregon near Heceta Bank (Figure
75) and least evident to the north and south of this point. At least six
submarine canyons transverse the seaward edge of the shelf. Shelf gradients
356
-------
-4S°N
42°
132°
REFERENCE: McManus, 1964; Gross, 1965.
Figure 74. Physiographic provinces off northwest Pacific
coast.
357
-------
I29°W
125°
120°
Guide Canyon
Aslorio Canyon
Eel Canyon
Mendocino Canyon
49°N
- 45°
40°
REFERENCE: McManus, 1964; Byrne, 1963a.
Figure 75. Relative positions of major submarine banks and
canyons off Northwest coast.
358
-------
range from 0.13 to 0.72° averaging less than 0.5° and are generally uniform
out to the shelf break.
Surface sediments of the nearshore zone are primarily sands consisting
of detrital quartz and feldspar. The sand zone extends from the shoreline
out to about 90 m (295 ft) off the northern and central Oregon coast (Byrne
1962), but forms a narrow belt along the southern Oregon coast at depths of
less than 50 m (164 ft). Off the Washington coast, the sand zone extends to
depths of 50 m (164 ft) or more. Seaward of this zone, bottom sediments
consist of patches of mixed sand and mud, modern mud, and exposures of bare
rock. The onshore-offshore movement of sand is greatest during the winter
when longshore transport is to the north.
A major portion of the outer shelf is covered by unconsolidated
sediment, with rock outcrops projecting above the shelf floor in several
places. Such outcrops occur primarily near the shelf edge where a number of
individual banks exist at approximately the 145 m (476 ft) contour (Byrne
1963a, b). The three major shoals occurring on the Oregon continental shelf
are the Stonewall, Heceta, and Coquille, with 60-73 m (197-239 ft) reliefs.
Published chart notations indicate a hard brown clay at Heceta, although
Byrne (1962) indicates that this is probably based on the collection of
shale or mudstone. Rocks collected at Stonewall are dense light-gray
fossiliferous mudstone and dense gray siltstone or fine sandstone. The
lithology of Coquille has yet to be defined.
Continental Sjope--The relatively narrow northern California-Southern
Oregon continentalsfielf is bordered by a topographically complex slope
which extends from the 145-185 m (476-607 ft) break to the deep sea floor at
approximately 1,800 m (5,905 ft) in the south and 1,400 m (4,593 ft) in the
north. The slope width varies from approximately 45 to 55 km (24-30 nmi) in
the south to between 60 and 80 km (32-43 nmi) in the north. The slope is
convex in shape off southern Oregon, whereas the central and northern Oregon
slope contains an outer terrace zone or continental borderland, which
disappears further to the north near Vancouver Island (Figure 76). This
seaward borderland is approximately 50 km (27 nmi) wide with narrow north to
northwest ridges and has a distinct marginal ridge. The interior ridges are
from 10 to 75 km (5.4-40 nmi) long and have reliefs of up to 1,150 m (3,773
ft) (McManus and McGary 1967). The average slope gradients are typically
somewhat less than 2°, but range from 1.8°-2.0° in the south to 1.2°-1.5° in
the north. Seaward of banks, declinations can be much greater, however.
For example, south of the Heceta Bank the slope gradient is as great as 40°
at the onset of the escarpment, tapering off to first 16° and then again
increasing to as much as 30° farther offshore.
Off both Oregon and Washington, the slope is broken by normal faulting
parallel to the shoreline, resulting in a number of structural benches and
basins similar to those associated with the side slopes of deep trenches
(Menard 1964). As the terrace widens to the north of the Gorda Escarpment
(Figure 77), a step develops at about 900 m (2,953 ft). Seaward of the
step, a marginal ridge drops to the deep-sea floor. Cascade Bench, which is
one of the largest on the slope, occurs between the 400 and 600 m depth
(1,312-1,968 ft), and another prominent bench occurs near the California
border at depths of 500 to 700 m (1,640-2,297 ft).
359
-------
125'00'
5 10
VERTICAL X13
TILLAMOOK
• BAY
45- 20
-------
S 0 N D
REFERENCE: Huyer and Smith, 1978.
Figure 77. Monthly mean values of the alongshore component
of the currents off the Oregon coast.
361
-------
Large submarine canyons notch the upper-slope and extend down to the
borderland. For example, the Astoria Canyon (Figure 75) meanders through
the ridge topography, commencing about 18 km (9.7 nmi) west of the Columbia
River mouth at the 182 m (597 ft) depth. The canyon extends 31 km (16.7
nmi) down to a 1,000 m (3,280 ft) depth, turning to the southwest and
continuing 24 km (13 nmi) to a depth of 1,500 m (4,921 ft). Thereafter the
canyon splits; the northwestern arm leads to the mouth of the Willapa
Canyon, while the west-southwest arm continues to the head of the Astoria
Fan. The Fan, whose apex is located at the 1,830 m (6,004 ft) depth,
extends 140 km (75.5 nmi) to the west and 230 km (124 nmi) to the south of
this point.
Continental Rise--Mendocino and Gorda Escarpments are major bathymetric
features that strike east-west into the continental margin. A 300 km (162
nmi) long segment of the oceanic rise, Gorda Ridge with its crestal
mountains and median valley, lies just north of the Mendocino Escarpment.
The northern limit of Gorda Ridge is formed by Blanco Fracture Zone, a 20 to
75 km (10.8-40.5 nmi) wide system of ridges and troughs that have an average
relief of about 900 m (2,952 ft), although depths exceed 5,100 m (16,732 ft)
in some troughs, and relief exceeds 2,750 m (9,022 ft) (Dehlinger et al.,
1970). The rough topography of the 460 km long zone (248 nmi) acts as a
barrier to turbidity current dispersal, reflected in the existence of the
deep-sea fans and plains in Cascadia Gap. Therefore, much of the sediment
of Tufts Abyssal Plain must have used that corridor. A northern
continuation of the Blanco Fracture Zone, the Juan de Fuca Ridge, is more of
a low rise than a wel 1-developed ridge. Seamounts and furrows are major
topographic elements of this ridge.
Abyssal Plain—Seaward of ridges and fracture zones is the depositional
topography of deep-sea fans and Tufts Abyssal Plain. Deep-sea channel
systems played a major role in construction of the low, smooth topography
(average gradient 1.4 m/km) cross this region. Gorda and Astoria Basins,
which are part of the Cascadia basin, are sites of major deep-sea fans
(e.g., Astoria Fan and Nitinat Fan, respectively).
Circulation Patterns-
Northwest coastal currents are generally parallel to local isobaths.
They have much stronger alongshore than onshore components, are highly
variable in both direction and speed on a time scale of several days, and
fluctuate in direct correlation to sea level changes and the longshore
component of the wind (Huyer and Smith, 1978). The longshore current system
exhibits a significant seasonality, with flows being generally northward at
all depths in the winter and strongly southward in the spring and summer
(Figure 77). A northward undercurrent develops above the outer shelf and
slope in late summer and early fall (Huyer et al., 1975).
The most prominent feature of Pacific Northwest shelf circulation is a
southward coastal jet during the upwelling season (Mickey 1979b). In
spring, the center of the southward flow moves from a summer position of 15
km (8 nmi) offshore to within 10 km (5.4 nmi) of the coast. The width of
362
-------
the flow increases at this time, extending out over the continental slopa
(Huyer et al., 1978). Currents at 25 to 40 m (82 to 131 ft) depths have a
net annual southward movement with average speeds being 10 cm/sec and 8.5
cm/sec at these two depths, respectively. Deeper, at 80 m (262 ft), the
average flow is typically much weaker and there is little net displacement
over long periods (Huyer and Smith 1978). Maximum monthly mean velocities
for the mid-shelf area range from 20 to 40 cm/sec. Extreme currents at 20 m
(66 ft) have exceeded 50 cm/sec in summer and 100 cm/sec in winter (Figure
78). Maximum surface currents are likely to be even higher than these
values.
Over the inner-shelf, the currents are apparently much weaker than at
mid-shelf. Measurements over 2-4 month periods between July and October
near the 50 m (164 ft) isobath indicate a weak average southward flow, which
at times reverses. When the wind stress remains southward for several days,
an offshore flow develops (Figure 79), with surface speeds of up to 20
cm/sec. Deeper shoreward replenishment flows below 15 to 20 m (49 to 66 ft)
water depths range from 5 to 10 cm/sec.
Although much less is known regarding the outer-shelf circulation
patterns, surface currents are generally believed to be southward. Beyond
the shelf, geostrophic calculations indicate a mean southward flow which is
weaker than at mid-shelf. Flows of 13 cm/sec have been measured at 40 m
(131 ft) depths in 500 m (1,640 ft) of water at the same section and time as
shelf measurements indicating a continuum of southward flow seaward beyond
the shelf (Figure 80).
At depths of 200 to 300 m (656 to 984 ft) there is a northward
undercurrent (Favorite et al ., 1976), whose presence has been verified off
Oregon in spring and early summer (Huyer and Smith 1976) and off Washington
in the late summer and early fall (Cannon et al., 1975; Reed and Halpern
1976). Between July and September, the northward flowing jet over the
Washington continental slope has been observed to be 20 km (10.8 nmi) wide
and 200 m (656 ft) thick, (excluding flow components below 5 cm/sec). A
maximum core speed of 16 cm/sec has been measured at a depth of 192 m (630
ft) in 600 m (1,968 ft) of water (Hickey 1979b). Below 60 m (197 ft),
slower northward flow was observed on the average over a six-week period
(July-September) as far as 80 km (43.1 nmi) offshore, across the slope and
over the entire shelf (Figure 65).
Representative Disposal Site Characteristics
Typical physical oceanographic conditions at shelf, slope, and basin
sites off the Oregon coast are presented in this section. Although the
salinity, temperature, and density profiles are isolated measurements, they
do represent conditions expected during the winter and summer periods. The
current profiles are mean currents over the winter and summer periods of
deployment. Further offshore, over the lower-slope and deep-ocean basin
where current measurements are not available, calculated geostrophic flows
are presented. The physical oceanographic information presented is based on
review of a relatively large number of technical reports (Table 54). The
locations of the stations selected as representative of disposal areas are
listed below and shown in Figure 81.
363
-------
CO
en
50
100
'50
200
.16
.27
.22
.19
Mo>. Speed
. 45*I6'N
Jul-Aug 1973
58.
IOO
. IO5 IO8/
Mox Speed
45*N
28 Jon-27 Apr
1975
20
0
DISTANCE
20
REFERENCE: Huyer and Smith. 1978.
Figure 78. The vertical-offshore distribution of the maximum current speeds
observed during July and August, 1973, and during February, March,
and April, 1975, off Newport, Oregon.
-------
100
£
200
. • Oregon
40 20
DISTANCE OFFSHORE (km)
REFERENCE: Huyer, 1976.
Figure 79. Onshore-offshore circulation pattern during
summer upwelling.
365
-------
-i 40
50
DISTANCE OFFSHORE (KM) /
40 30 20 10
30 O
I
20 cc
O
10
10
20
30
40
50
I
a,
e
1
LU
O
tr
x
o
to
9 JULY
14 JULY
15 JULY
16 JULY
17 JULY ..
REFERENCE: Huyer 1974
Figure 80. Components of surface current vs. distance offshore
the Oregon coast.
366
-------
TABLE 54. REFERENCES REVIEWED TO COMPILE PHYSICAL OCEANOGRAPHIC
INFORMATION ON CHARACTERISTIC DISPOSAL AREAS
OFF THE NORTHWEST COAST
McManus 1964
Gross 1965
Shepard 1963
Byrne 1962
Byrne 1963a,b
Byrne and Panshin 1977
McManus and McGary 1967
Menard 1964
Dehlinger et al., 1970
•
.Roden 1964
Tully 1964
Huyer and Smith 1978
Bourke and Pattullo 1974
Pattulo and Denner 1965
Barnes et al., 1972
Huyer 1977
Hal pern 1974
Pak et al., 1970
Huyer et al., 1974
Hal pern et al., 1973
Huyer et al., 1975
Hays and Hal pern 1976
Huyer and Smith 1976
Huyer et al., 1978
Huyer 1976
Favorite et al., 1976
Cannon et al., 1975
Reed and Hal pern 1976
Hickey 1979a,b
Huyer 1974
Stephansson and Richards 1964
Pak and Zaneveld 1978
Curl et al., 1965
Harlett 1972
Kitchen et al., 1975
367
-------
125*30'
125 °W
124'30'
40' -
30
REFERENCE: Huyer et al. 1975
Figure 81. Current meter locations during 1973.
368
-------
Location Summer Ui nte r
Shelf Carnation Sunflower, 2D
Upper-slope Edelweis 8D
Mid-slope Forsythia, 389, 390 190
Slope Edge/Basin Gladiolus, 391 160
Shelf--
August temperature, salinity, and density characteristics at station
Carnation in 90 m (295 ft) of water on the Oregon shelf are presented in
Figure 82 January data for the same parameters are presented in Figure 83.
The 6° C temperature gradient in the upper 20 m (66 ft) in summer becomes
very small in winter down to the 40 m (131 ft) level. Beyond this depth,
temperature variations are slight, decreasing to 6° C in deeper waters. The
density profile indicates a significant dependence on salinity in both the
winter when the temperature gradient is small, and during the summer when a
strong thermocline is present. Mean currents for the 99 m (324 ft) deep
station Carnation and the 100 m (328 ft) station Sunflower during summer and
winter months, respectively, are presented in Figure 84. As indicated,
longshore velocity components are much greater than onshore components, and
near surface flows are predominantly southward on the average in both summer
and winter periods. Movement below 75 m (246 ft) is northward during both
seasons.
The distribution of dissolved oxygen (DO) in northwest coastal waters
is complicated due to upwelling, freshwater discharges, entrainment of deep
water and wave action (Stephansson and Richards, 1964). Biological activity
nearshore is also more intense and more variable than farther offshore.
Maximum surface DO values of 10.0 to 10.7 mg/1 occur nearshore between June
and July (Figure 85). The generally high surface values exceed levels
expected for colder upwelled waters in atmospheric equilibrium, and are
attributable to high photosynthetic production rates.
Temperature, salinity, and density data for summer and winter periods
at upper-slope stations Edelweis and 8D are presented in Figures 86 and 87,
respectively. A strong thermocline and halocline persist during the summer
in the upper 10 m (33 ft). In winter, smaller gradients occur and two
stratification levels appear at approximately 10 and 60 m (33 and 179 ft),
the upper one being due to cool low-salinity water very near the surface.
Upper slope currents are strongly southward in summer down to 100 m (328
ft), beyond which a slow northward current occurs (Figure 88). average
currents down to 150 m (492 ft) persisted in an onshore direction during the
30-day measurement period. In winter (January-April), the mean longshore
current magnitudes are very low,.with some southward movement down to 100 m
(328 ft) and northward flow beyond to the sea floor. Mid-slope temperature
and salinity profiles (Figures 89, 90) appear similar to those on the
upper-slope during both the summer and winter periods. Southward currents
persist from 50-200 m (164-656 ft) while movement in the onshore direction
is very slight (Figure 91).
369
-------
SALINITY (ppt)
3000 31.00 32.00 33.00
I I 1 1—
10J
20
30-
co
£ 40-
I w
X
& 60-
70-
80-
90-
100-
34.00
35.00
_J
TEMPERATURE (°c)
6.00 7.00 8.00 9.00 10.00 11.00 12.00 13.00 14.00 15.00
TEMP.
SAL
SIG.
21.00
22.00
23.00
24.00
SIGMA-T
25.00
26.00
27.00
REFERENCE: Gilbert et al. 1976
Figure 82. Summer (August 23, 1973) temperature, salinity,
and density profiles at Station Carnation
(99 m). Lat. 45°14.7'N, Long. 124°06.9'W.
370
-------
30
L_
I
I
LU
o
20.-
40.-i
60.-,
80.-
100.-
24
31
SALINITY (ppt)
32 33
-J L_
34
35
J
TEMPERATURE (t)
10 14
18
22
SHELF
WINTER
TEMP.
SIG.
SAL
I
25
I
26
27
28
29
SIGMA-T
REFERENCE: Gilbert et al. 1976
Figure 83. Winter (January 28, 1975) temperature and
density profiles at Station 2D (97 m).
Lat. 45°00.2'N, Long. 124°09.8'W.
371
-------
VELOCITY
(cm/sec)
W
10
i
5
i
VELOCITY
(cm/sec)
W
E S
SHELF/SUMMER
CARNATION 6/30 - 8/28/78
-10
SHELF/WINTER
SUNFLOWER 1/27 - 4/27/75
VELOCITY
(cm/sec)
-20
j
-15
i
-10
i
-5
I
+ 50
1-100
VELOCITY
(cm/sec)
5
!
±50
+ 100
10
Q.
IXI
Q
5
I
Q.
LU
Q
10
DATA FROM: Gilbert et al. 1976
Figure 84. Mean current velocity profiles for Oregon
continental shelf locations in summer and
winter.
372
-------
TIME IN MONTHS
A M J J ASOND
g
r
UJ
a
10
20
30
6.50
7.25
I I
6.T3
n*l/Mr«
-*« * >
6.25^6'° 5.0
^ i^ yf x
Temperature
Sigma-/
Oxygen
concentrations
(ml/I)
Figure 85.
REFERENCE: Stefansson and Richards. 1964
Mean seasonal variations on
upper 30 m inside the 150-m
46°50' and 47°40'N Lat.
properties in the
isobath between
373
-------
30.00
6.00
SALINITY (ppt)
31.00 32,00 33.00
_J I L_
34.00
35.00
_J
200-
TEMPERATURE (°c)
10.00 11.00 12.00
I I L
15.00 16.00
UPPER SLOPE
SUMMER
21.00
23.00
24.00
SIGMA -T
25.00
26.00
27.00
REFERENCE: Gilbert et al. 1976
Figure 86. Summer (August 24, 1973) temperature, salinity,
and density profiles at Station Edelweis
(196 m). Lat. 45°15.3'N, Long. 124°18.0'W.
374
-------
30
I
31
I
32
I
SALINITY (ppt)
33
I
34
I
35
TEMPERATURE (°c)
10 14
I I
18
I
22
UPPER SLOPE
WINTER
50-
co
£ iooH
HI
2
I
X
UJ
o
150-
200-
TEMP,
SIG.
SAL
250-
24
25
I
26
I
27
1
28
29
SIGMA-T
REFERENCE: Gilbert et al. 1976
Figure 87. Winter (January 28, 1975) temperature, salinity,
and density profiles at Station 8D (218 m).
Lat. 45°01.2'N, Long. 124°22.3'W.
375
-------
VELOCITY (cm/sec)
-5 0
VELOCITY (cm/sec)
-10 -5 0
UPPER SLOPE
SUMMER
-L 200 EDELWEISS (200m) 7/22 - 8/28^73 JL 200
VELOCITY (cm/sec)
-505
UJ
Q
-•50
100
--150
UPPER SLOPE
WINTER
VELOCITY (cm/sec)
-505
-L 200 WISTERIA (225m) JAN.-APRIL 75 -^ 200
--50
- -100
--150
DATA FROM: Gilbert et al. 1976
Figure 88. Mean current velocity profiles for Oregon
upper-slope locations in summer and winter.
376
-------
31.00
I
32.00
500-
SALINITY(ppt)
33.00 34.00
_L
4.00 5.00
6.00 7.00
I
TEMPERATURE (°c)
35.00
I
36.00
8.00
I
9-00 10.00 11.00 12.00 13.00 14.00 15.00
i i
MIDSLOPE
SUMMER
22.00
23.00
24.00 25.00
SIGMA-T
26.00
27.00
REFERENCE: Gilbert et »1. 1976
Figure 89. Summer (August 24, 1973) temperature, salinity,
and density profiles at Station Forsythia
(492 m). Lat. 45°15.2'N, Long. 124°39.8'W.
377
-------
30
cc
UJ
UJ
g] 300
Q
31
_L
SALINITY (ppt)
32 33
I
TEMPERATURE (ccJ
10 14
SIGMA-T
MIDSLOPE
WINTER
Figure 90.
REFERENCE: Gilbert et al. 1976
Winter (January 29,
and density profiles
Lat. 45°00.0'N, Long
1975} temperature, salinity,
at Station 190 (435 m).
124°16.0'W.
378
-------
CO
IO
w
VELOCITY
(cm/sec)
0
Q.
UJ
Q
100
150
200
«10 -5
MIDSLOPE/SUMMER
VELOCITY
(cm/sec)
0
FORSYTHIA 500m 6/30-8/26/73
50
100
Q.
UJ
Q
150
200
DATA FROM: Gilbert et al. 1976
Figure 91. Mean current velocity profiles for an Oregon mid-slope location in
summer and winter.
-------
Lower-Slope and Upper-Basin--
In lieu of measured currents in the offshore area, calculated
geostrophic flow profiles for the area between stations 389 and 391 are
presented in Figure 92. Summer surface currents at 65 km (35 nmi) offshore
are southward in summer, decreasing from approximately 6 cm/sec to no
current at a depth of, 150 m (492 ft). In an adjacent area 10 km (5.4 nmi)
further offshore, near-surface southward currents of 5 cm/sec decrease to
negligible speed at 50 m (164 ft). Representative lower slope/upper basin
temperature, salinity, and density profiles are shown in Figures 93 and 94
for summer and winter periods, respectively.
Beyond the continental shelf, upper DO values remain relatively
constant in the upper mixed layer at near 9.0 mg/1. DO concentrations
increase to maxima of 9.3 to 9.6 mg/1 between March and May. As the
temperature further increases in summer, lower DO solubility results in
decreased surface concentrations of aproximately 8.2 mg/1 in the upper 10-20
m. A subsurface maximum at depths of 20 to 50 m persists at the previously
established winter concentration of 9.6 mg/1 however. Figure 95 presents
the mean seasonal variations in DO and other parameters in the upper 100 m
for an offshore area.
Biological Characteristics
Open Ocean Environments off the Pacific Northwest--
In open ocean environments beyond the continental slope offshore from
the Pacific Northwest coast, virtually all primary production is performed
by phytoplankton. Due to its dependence on sunlight, phytoplankton
production is limited'to the upper (< 60 m) sunlit layers of the ocean in
this region. All other life (with the possible exception of some benthic
organisms which ingest organic matter carried into the deep sea by turbidity
currents) in these environments is dependent on the fixation of carbon by
phytoplankton, and hence production by the phytoplankton is essential to all
higher trophic levels. Phytoplankton production in open ocean waters
offshore from the Pacific Northwest coast is limited by low light levels and
high turbulence during most of the winter months. There is generally a
large increase in phytoplankton production in spring, coinciding with
stabilization of the upper water column and increasing light levels. Due to
an excess of precipitation over evaporation in this area, there is a
permanent halocline at depths of 100-150 m. This has the effect of limiting
the upward transport of nutrients to the euphotic zone, and consequently the
increased phytoplankton production in spring depletes the nutrients
(especially nitrogen in the form of nitrate) in the surface layer.
Production throughout the summer is therefore limited by the availability of
fixed nitrogen (Peterson et al., 1979). Regeneration of nutrients by
animals is important, but due to losses from the upper layers (e.g., the
sinking of fecal pellets), it cannot completely supply the required
nutrients. While production in spring may be high, the summertime nutrient
limitation of phytoplankton production is responsible for keeping the annual
production low relative to coastal and nearshore areas (125 g C/m2 in
offshore areas vs. 300 g C/m2 in coastal and nearshore areas; cf. Anderson
380
-------
-6.0 -5.0
VELOCITY (cm/sec.)
-4.0 -3.0
J I
LOWER SLOPE/UPPER BASIN
SUMMER
-100
-150
-200
-250
-300
DEPTH(m)
VELOCITY (cm/sec.)
-4.0 -3.0 -2.0 -1.0
LOWER SLOPE/UPPER BASIN
SUMMER
-50
-100
-150
-200
-250
-300
DEPTH (m)
DATA FROM: Gilbert et al. 1976
Figure 92. Summer (August 24, 1973) calculated geostrophic current profile,
slope edge/basin location (Stations 390-391, Figure 6-34).
-------
31.00
I
100 -
200-
300 -
400 -
500 -
600-
700 -
800 -
900 -
1000 -
1100 -
1200 -
1300 -
1400 -
32.00
I
SALINITY (ppt)
33.00 34.00
I
I
35.00
I
36.00
I
TEMPERATURE (cc)
2.00 4.00 6.00 8.00 10.00 12.00 14.00
I i I I I I
16.00
LOWER SLOPE/UPPER BASIN
SUMMER
TEMP.
SAL
SIG.
22.00
23.00
24.00
I
25.00
SIGMA-T
26.00
27.00
28.00
REFERENCE: Gilbert et al. 1976
Figure 93. Summer (August 24, 1973) temperature, salinity,
and density profiles at Station Gladiolus (1,412 m)
Lat 45018.9'N5 Long. 125°00.1'W.
382
-------
29
30
31
_L
SALINITY (ppt)
32 33
-I l_
QC
LLJ
u
Q.
LU
a
100-
200-
300-
400-
500-
600-
12
TEMPERATURE (°c)
16 20
TEMP.
LOWER SLOPE/UPPER BASIN
WINTER
SIG.
SAL
24
1
25
I
26
I
27
28
I
29
30
SIGMA-T
REFERENCE: Gilbert et al. 1976
Figure 94. Winter (January 29, 1975) temperature, salinity,
and density profiles at Station 16D (1,356 m).
Lat. 45°00.0'M, Long. 125°12.0'W.
383
-------
JFMAMJJ iSONDJF MA
Temperature
Sigma-/
Oxygen
concentration
(ml/1)
REFERENCE: Stefansson and Richards, 1964.
Figure 95. Offshore mean seasonal variations of properties
in the upper 100 m inside the area between
14°30'-47°30'N Lat. and 126°30'-130030IW Long,,
January, 1961 - March, 1962.
384
-------
1972). Production at all higher trophic levels can be expected to be
correspondingly lower in the offshore areas.
Above the permanent halocline, a seasonal pycnocline generally develops
at a depth of 10-20 m in spring. This gradually deepens to a depth of ^40 m
in autumn (Anderson 1972). One result of the supply of nutrients from
deeper waters is that phytoplankton biomass is often greater deep in the
euphotic zone than at shallower depths. Anderson (1972) reported, for
instance, that a subsurface maximum in chlorophyll £ concentration (a
commonly-used measure of phytoplankton standing stock) iT typically found at
depths of ^60 m in this area in summer. Chlorophyll a concentrations within
this subsurface maximum may be 5-15 times higher than" those at the surface.
Nitrate concentrations- also increased rapidly at a depth of 60 m, suggesting
that the phytoplankton at this depth have sacrificed living higher in the
water column, where light levels are greater, for the sake of being near a
source of nutrients.
Anderson (1972) reported that in winter in these offshore areas,
diatoms dominated the phytoplankton community, although dinoflagellates,
coccolithophorids, and other flagellates were also abundant. During the
spring bloom, diatoms became even more dominant, while dinoflagellates
decreased in importance and coccolithophorids disappeared completely. Net
phytoplankton [defined by Anderson (1972) as cells > 35 urn in size] were
always a small part of the total phytoplankton community.
Due to the slow, southward flow of the California Current at distances
of 300-800 km off the Pacific Northwest coast (Peterson and Miller 1975),
zooplankton inhabiting the offshore region are predominantly subarctic in
faunistic affinity. Calanoid copepods, many of which are filter-feeders,
are particularly abundant (Marlowe and Miller 1975). While many zooplankton
species inhabit the euphotic zone, others perform limited (< 200m) diel
vertical migrations which bring them into the euphotic zone only at night.
Zooplankton occur at all depths throughout the water column in this area,
but those occurring below about 200 m are almost exclusively carnivores
and/or detrivores.
All animals larger than zooplankton which inhabit the water column are
classified as nekton. This group includes not only fishes, but squid,
shrimp, whales, dolphins, etc. Common fishes occurring within the
epipelagic zone offshore from the Pacific Northwest include pomfret (Brama
japonica) and several species of salmon. The salmon are noteworthy, not
only because of their commercial and recreational value in nearshore
fisheries, but also because of their anadromous life-cycle, which brings
them back to freshwater rivers and streams of the Pacific Northwest for the
purpose of spawning. Pomfret, on the other hand, are entirely pelagic.
Other occasional residents of the offshore epipelagic zone include albacore,
which, although it is more typically a southern species, may extend its
range this far north during the summer if ocean temperatures are
sufficiently warm. Marine mammals of the northeast Pacific include various
whale and porpoise species. The larger nekton species are generally strong
swimmers which range over large areas of the oceans and are not restricted
to a single geographic area. Because these large species of nekton are a
385
-------
number of trophic levels removed from the primary producers, they are quite
rare considering the total expanse of the oceans. Nevertheless, certain
species (e.g., whales, porpoises) are known to school, and consequently they
may be abundant in a given area for a short period of time.
A number of small nektonic species in the northeast Pacific inhabit
mesopelagic depths (100-1,000 m) and some of these perform die! vertical
migrations into the epi pelagic zone (< 100 m) [cf. Pearcy et al. (1977);
Frost and McCrone (1979)]. While these species are widespread, individuals
of these species are not as wide-ranging as those of the larger, epipelagic
species.
With the notable exception of the anadromous fishes, most other pelagic
fish species in offshore waters of the northeast Pacific lay and fertilize
their eggs in the sea itself. The eggs and larvae, collectively referred to
as ichthyoplankton, are carried about by the currents. The larvae are
typically very small, and dependent on plankton for food.
Benthic animals, including both organisms living in and on the sea
floor and demersal organisms swimming just above the sea floor, are largely
dependent on the production of organic matter in the overlying waters.
Organic matter is transported to the deep-sea benthos by sinking carcasses,
fecal material, exoskeTetons, and detritus, by the vertical migrations of
some nektonic species, and in some areas by turbidity currents. Since the
supply of organic matter is inversely related to the distance from the
surface, deep benthic life in the northeast Pacific is sparse by comparison
to benthic communities in shallow, nearshore areas.
The abundance of sea floor organisms generally decreases with
increasing distance from shore off Oregon [Carey (1965); Griggs et
al. (1969)]. Large benthic populations found in some areas may be
associated with higher food input to the bottom environment. Griggs et
al. (1969) reported, for instance, that while benthic organisms were
relatively sparse at stations located over areas of the Cascadia Abyssal
Plain far removed from the continental slope, there were four times as many
organisms present at stations at the base of the continental slope and in
the axis of the Cascadia Channel (a submarine canyon which crosses the
Cascadia Abyssal Plain, and is apparently associated with the Columbia River
discharge). The former stations were characterized as having postglacial
depositional rates of 2-3 cm/1,000 years, while the latter stations had
postglacial depositional rates of 8-10 cm/1,000 years. The higher rates are
believed to be associated with the settling of large volumes of suspended
sediments from the Columbia River discharge (Griggs et al ., 1969). The
higher organic carbon content of the surface sediments at the easternmost
stations on the Cascadia Abyssal Plain, relative to that of those stations
to the west (1.7 percent vs. 1.1 percent), may be associated with higher
primary productivity of the overlying waters (due to coastal upwelling), and
the large volume of suspended sediments and particulate matter from
terrestrial runoff in the Columbia River discharge. The organic carbon
content of the surface sediments within the Cascadia Channel is still higher
(2.2 percent), and is believed to be a result of turbidity currents which
originate on the outer continental shelf and the upper continental slope
386
-------
where primary production in the overlying water column is high, and where
terrigenous material from the Columbia River drainage is deposited (Griqqs
et al., 1969).
Many species of the benthic infauna at abyssal depths are deposit
feeders which are dependent either on the settling of organic matter from
the surface waters or on the transport of organic matter to abyssal depths
by some other means, such as turbidity currents. Annelids are the
numerically dominant infauna at all locations on the Cascadia Abyssal Plain
(Griggs et al., 1969). They are, however, less abundant at the westernmost
stations, perhaps due to the sand which underlies a thin (2-15 cm) layer of
finer postglacial sediments on the surface. Annelids are numerically more
abundant at the base of the continental slope and in the Cascadia Channel,
but the biomass of benthic infauna (chiefly annelids) is higher at the
latter location, presumably due to the higher organic carbon content of the
sediments and the greater input of such sediments through turbidity
currents. Other abundant infaunal organisms in this general area include
arthropods and mollusks. Epifaunal organisms include holothurians,
ophiuroids, and other forms (Griggs et al., 1969).
The Cascadia Channel thus appears to be an avenue for transporting
terrestrial detritus into the deep sea. While terrestrial plant fragments
may not be directly utilized by benthic macrofauna, they may be the initial
step in an abyssal food web involving bacteria, other micro-organisms, and
eventually the macrofauna (Griggs et al., 1969).
Demersal fish communities over the Cascadia Abyssal Plain are dominated
both numerically and by weight by macrourids. While small macrourids prey
largely on benthic organisms, the primary food of larger individuals appears
to be pelagic organisms (Pearcy and Ambler 1974). These fishes are perhaps
best characterized as both predators and scavengers. They are not dependent
on large organic falls (e.g., sinking carcasses), but are instead adapted to
utilize a wide variety of prey types. It is not clear whether they
occasionally rise far above the bottom to ingest pelagic prey, or whether
the prey itself approaches the bottom and is ingested there (Pearcy and
Ambler 1974).
Outer Continental Shelf Environments off the Pacific Northwest Coast-
As in open ocean environments, virtually all of the primary production
over the outer continental shelf of the Pacific Northwest is attributable to
phytoplankton. Unlike open ocean waters, however, where both phytoplankton
standing stock and primary production are typically low due to light
limitation in winter and nutrient limitation in summer, phytoplankton
production over the shelf may be considerably higher, due in large part to
seasonal coastal upwelling (Peterson and Miller 1975). During fall and
winter (October-March), the prevailing winds are from the south, and the
resulting surface flow is to the north and onshore. During spring and
summer (Apri 1-September), however, the prevailing wind is from the north,
and the surface flow is to the south and offshore. This results in the
upwelling of deeper, nutrient-rich water over the shelf. This upwelling is
not a constant process, but varies with the strength of the wind. It is
387
-------
often most pronounced during the months of July and August (Peterson and
Miller 1975).
Upwelling is generally most intense at a distance of approximately
10 km from the coast, but it affects an area approximately 50 km wide,
extending out over the upper continental slope (Peterson et al., 1979). The
surface layer moving seaward may only be 5 m deep within 10 km of the coast,
but deepens to 10-15 m farther offshore. The water which is upwelled
originates over the outer continental shelf (20-35 km offshore) in depths of
100-200 m. Because this water is rich in nutrients, it is capable of
stimulating phytoplankton production, which otherwise would be limited by
the availability of fixed nitrogen, just as in the open ocean waters in
summer. Hence, during intense upwelling, dense phytoplankton concentrations
exhibiting high production are found near the surface from a few kilometers
offshore to the edge of the continental shelf and sometimes beyond (Peterson
et al., 1979). As a consequence, annual phytoplankton production over the
shelf is high (300 g C/m2) relative to offshore areas (125 g C/m2) (Anderson
1972).
The Columbia River plume (a region of lower salinity water near the
surface) may extend over parts of the continental shelf and slope in spring
and summer. This plume may stabilize the upper water column earlier in the
year than would thermal stratification, and therefore the spring bloom may
occur earlier in areas affected by the plume. In such areas, however, the
resulting halocline limits upward transport of nutrients in summer, and
causes the phytoplankton to be nutrient limited. In areas affected by the
plume, the annual primary productivity may be no greater than in offshore
regions (125 g C/m2) (Anderson 1972).
Anderson (1972) reported that over the shelf, diatoms dominated the
winter and spring phytoplankton communities. Net phytoplankton (defined as
cells > 35 urn in size) were always a small part of the total phytoplankton
community.
Zooplankton inhabiting the waters overlying the continental shelf are
predominantly subarctic in faunistic affinity. Five copepod species
dominate the zooplankton community, and each has a different pattern of
distribution (Peterson et al., 1979). Acartia clausi is almost completely
restricted to the upper 5-10 m of the water column and the first 5 km from
shore. Pseudocalanus sp. is abundant from 0-15 km from shore and between
10-20 m depth, but it reproduces only within a few kilometers of shore.
Acartia longiremis lives and reproduces offshore (10 km) in the surface
(0-10 m) mixed layer. Oithona si mil is is abundant offshore (10 km) between
10-20 m depth. Calanus marshal!ae~1 ives offshore as older copepodite
stages, but the females return shoreward and lay their eggs at about 10 km
from shore. The nauplii and younger copepodites of C. marshallae develop in
the very nearshore zone. Other less abundant zoopTankton species probably
have distributions similar to one or another of the above. The population
of each species appears to be maintained within the upwelling zone by a
specific relationship between its distribution, life cycle, and the shelf
circulation patterns (Peterson et al., 1979). Most of the abundant
zooplankton species are herbivores, and hence their populations may be
enhanced by the presence of coastal upwelling.
388
-------
Some pelagic fishes of the open ocean are also common in waters over
the continental shelf (e.g., salmon); other abundant pelagic fishes may be
more or less confined to coastal waters [e.g., Pacific mackerel (Scomber
japonicus). northern anchovy (Engraulis mordax); cf. Clemens and Wilby
1961].
Waters above the continental shelf of the Pacific Northwest coast
represent an important migratory route for California gray whales
(Eschrichtius robustus), which annually migrate between feeding grounds in
the Bering Sea and breeding grounds off Baja California. Other marine
mammals [e.g., killer whales (Orcinus orca), sea otters (Enhydra lutris),
and porpoises] are known to inhabit the area.
Due to the relatively shallow water column over the continental shelf,
there is essentially no mesopelagic fauna there.
Benthic communities on the continental shelves are strongly influenced
by the physical-chemical environment. Important factors include the amount
of wave energy reaching the bottom, the grain size of the sediments, and the
organic content of the sediments. Off the Oregon coast, for example, the
bottom out to a distance of approximately 20 km from shore is 100 percent
sand, with a very low organic carbon content. This is a consequence of the
large waves passing over the shelf, which apparently have enough energy down
to depths of 80 m to keep smaller sediment particles in suspension.
Beyond 20 km from shore, the silt and clay fraction of the sediments
increases, until at the shelf break, silt and clay represent 30 percent of
the sediments on the bottom. The organic carbon content of the sediments
also increases with increasing distance from shore. This is in part a
consequence of the decreasing particle size, since organic materials tend to
be adsorbed onto clay and silt size particles. It also reflects the higher
primary productivity over the outer shelf, which is a result of coastal
upwelling (Carey 1972).
Over sand substrates on the inner continental shelf, macroepibenthic
organisms are relatively rare, and dominated by mollusks (Carey 1972).
Farther offshore, shrimps, echinoids, and ophiuroids are common, and by the
time the shelf break is reached (depths of 150-200 m) shrimps have become
the dominant macroepibenthic organisms (Carey 1972). On the outer shelf,
crabs, polychaetes, and gastropods are. also common. Both the numerical
density and the biomass of the macroepibenthos increase with distance
offshore to depths of 200 m. Carey (1972) reported, for instance, that the
biomass of macroepibenthic organisms was 73 times higher at a depth of 200 m
than at a depth of 50 m off the Oregon coast.
Unlike the epifauna, the infauna has a bimodal distribution; numerical
abundance of infauna is high both close to shore and near the edge of the
shelf (Carey 1972). Biomass estimates are not as readily available for
infauna, although there are indications of a large standing stock near the
edge of the shelf. Nearshore, the infaunal communities are dominated by
filter-feeding organisms, such as gammarid amphipods. On the outer half of
the shelf, the infaunal communities are dominated by deposit-feeding
389
-------
organisms, especially polychaetes. The high abundance of filter-feeding
organisms on the inner shelf reflects the fact that the bottom is within the
euphotic zone, so these infaunal organisms have access to phytoplankton.
The abundance of deposit-feeding organisms on the outer shelf is a
consequence of the finer particle size and the higher organic content of the
sediments (Carey 1972).
Demersal fishes are particularly abundant at depths of 91-411 m
offshore of the Pacific Northwest coast (Alton 1972). On the outer
continental shelf (at depths of 91-183 m) rex sole (Glyptocephalus
zachirus), English sole (Parophrys vetulus), slender sole (Lyopsetta
exi'lis), and blackbelly eel pout (Lycodopsis pacifica) are abundant. Rex
sole are known to feed on polychaetes. Both Engli sh sole and blackbelly
eelpout feed on polychaetes, clams, and brittlestars. Slender sole, on the
other hand, apparently feed primarily on euphausiids and other pelagic
crustaceans (Alton 1972). On the upper continental slope (at depths of
183-411 m) rockfishes (notably Pacific ocean perch, Sebastes alutus), Dover
sole, and Pacific hake (Merluccius productus) are abundant.™ RockfTshes and
hake ingest pelagic organisms, such as fishes and squid, while Dover sole
prey on benthic organisms (Alton 1972). Seasonal changes in the
availability of demersal fishes on the shelf appear to be related to onshore
movements of several species: Pacific hake, Dover sole, arrowtooth flounder
(Atheresthes stomais), and sablefish (Anoplopoma fimbria) (Alton 1972).
Nearshore Environments of the Pacific Northwest Coast--
The coastline of the Pacific Northwest includes rocky headlands, sandy
beaches, and estuaries (e.g., Grays Harbor, Willapa Bay, Columbia River,
Tillamook Bay). Only the open ocean environments (exclusive of the
estuaries) will be discussed below. Each represents a unique habitat for
marine organisms.
Along some sandy beaches of the Pacific Northwest, especially those in
Washington, a curious community of diatoms is particularly abundant in fall,
winter, and early spring (Lewin and Hruby 1973). These diatoms, primarily
Chaetoceros armatum and Asterionel la social is, are abundant only in the surf
zone. Chaetoceros armatum is particularly interesting because it is well
adapted to growing when ambient light intensities are so low that planktonic
diatoms are unable to achieve any net production. This centric diatom
floats on the surface during the day, and alters the surface properties of
the surf bubbles in such a way that a stable foam is formed (Lewin and Hruby
1973). Waves carry these foamy masses towards shore, retaining these cells
within the surf zone. When the tide recedes, there is a tendency for this
material to be left behind on the beach, which also tends to retain these
cells within the area. Cells not deposited on the beach are dispersed
throughout the water column at night. Flotation at the surface during the
daytime and intermittent stranding on the beach positions the cells where
they can receive the maximum available light (Lewin and Hruby 1973).
Pacific razor clams (Siliqua patula) appear to be the dominant
herbivore utilizing these surf-zone diatoms (Lewin et al., 1979). These
abundant burrowing clams inhabit the sandy beaches both intertidally and
390
-------
subtidally. They must feed on the diatoms primarily at night when the cells
are dispersed throughout the water column. Dissolved nitrate may be
available in very low concentrations in the surf zone during the summer.
During such times, the excretion of ammonium as a waste product by these
clams may be important for the continued growth of the surf-zone diatoms,
since ammonium can serve as another source of fixed nitrogen (Lewin et al..
1979).
Rocky shorelines of the Pacific Northwest provide hard substrate for
the attachment of benthic algae and many animal species. While the benthic
algae are important primary producers in this environment, the fact that the
competitive dominant benthic organism on wave-swept rocky intertidal shores
is a filter-feeder, the California mussel (Mytilus californianus (cf. Paine
and Levin 1981), indicates that phytoplankton are also abundant. The
communities inhabiting these rocky shorelines are complex assemblages of
organisms which include representatives of many of those types common on
rocky shorelines worldwide (e.g., starfish, limpets, chitons, barnacles, sea
urchins, sea anemones, brown and red algae, etc.). These rocky shorelines
also provide important habitat for Stellar sea lions (Eumatopias jubata) in
Oregon and the recently re-introduced sea otters (Enhydra "1 utris) in
Washington.
Extending offshore from just beyond the surf zone to a distance of
approximately 10 km from the coast is a region where phytoplankton
production may be influenced by many of the same factors mentioned above in
conjunction with the discussion of primary production over the outer
continental shelf. Coastal upwelling is an important feature in this region
in summer, but is should be noted that during intense upwelling, the water
found near the surface in this region has only recently been upwelled and is
consequently high in nutrients but low in chlorophyll (an indicator of
phytoplankton standing stock). Chlorophyll concentrations may be an order
of magnitude lower than in the region farther offshore, where phytoplankton
have had time to respond to the increased availability of nutrients
(Peterson et al., 1979). During relaxed upwelling, the offshore surface
waters will again move shoreward and large phtyoplankton blooms may develop
within the nearshore region. If upwelling does not occur for an extended
period of time, a subsurface chlorophyll maximum may form, and chlorophyll
concentrations at the surface will again be low (Peterson et al., 1979).
The nearshore region constitutes a very special habitat for
zooplankton, since a number of species (e.g., the copepods Acartia clausi
and Centropages abdominalis; the cladocerans Evadne nprdmanni and Podon
leukartii) are virtually restricted to this region. Their mechanisms for
remaining within this area, even during periods of intense upwelling, are
not entirely understood (Peterson et al., 1979).
Abundant subtidal benthic organisms on sandy substrates in the
nearshore environment include the previously mentioned filter-feeding
amphipods and razor clams. Large epifaunal organisms are not as abundant as
farther offshore, presumably due to the heavy wave action (Carey 1972).
391
-------
Pelagic fishes of the nearshore environment off the Pacific Northwest
coast include some of those species discussed previously with regard to the
continental shelf environment (e.g., Pacific mackerel, northern anchovy,
salmon).
Pacific Northwest Fisheries--
Fishing is an important economic activity in the states of Washington
and Oregon. In 1980, nearly 128,000 mt of fish were landed in the two
states with a landed value of over $141 million (Resource Statistics
Division 1981). Fisheries range from those conducted on rather low-valued
groundfish to those for high-valued species such as salmon and Dungeness
crab.
Ocean currents are a major influence on the coastal and high seas
fisheries of the Pacific Northwest. Coastal currents flow in a northerly
direction over the shelf in the winter and then reverse direction during the
spring (Glude 1971). The distribution and abundance of pelagic species are
influenced by these current patterns. During the summer months, warm
offshore currents bring albacore (Thunnus alalunga) to the Pacific Northwest
region where an intensive, short-term fishery is conducted in some years.
The second important oceanographic characteristic with respect to the
fisheries of this region is the relatively narrow continental shelf. A
maximum shelf width of approximately 65-70 km occurs off Central Oregon
(Heceta Bank) and at the mouth of the Columbia River (PFMC 1980). The
average shelf width is 50 km off Washington and 40 km off Oregon. The small
area of the shelf limits the size of potential demersal fishery resources.
A variety of fishing gear is employed in the northwest; this includes
bottom trawls, mid-water trawls, pots, set nets, longlines, and trolling
gear.
Fishing Areas—The northwest trawl fishery is conducted over a range of
depths on the continental shelf and slope. It is a multispecies fishery
with catch composition gradually changing with distance along the coast.
Forty-eight species define the management unit in the Pacific Fishery
Management Council's Groundfish Fishery Management Plan (PFMC 1980). These
species range from the underutilized sharks and skates to the 22 species of
rockfish.
In Oregon, bottom trawls are fished in depths to 457 m, primarily in
the area between the Columbia River and Tillamook Head, and off Newport.
Target species include lingcod (0p h i o d on el on gat us), Pacific cod (Gadus
macrocephalus), Pacific hake (whiting) (TOerlucci us productus), sablefish
(AnopTopoma fimbria), rockfishes (Sebastes spp.), Dover sole ~(Microstomus
pacificus), English sole (Parophrys vetulus), petrale sole (Eopsetta
jordani) ,~rex sole (Glyptocephal us zTchirus), and other flatfishes (Glude
1971; PFMC 1980). Similar species are exploited by Washington fishing
fleets to depths of 732 m (PFMC 1980).
392
-------
Limited deepwater bottomfisherles for grenadiers (Coryphaenoides
acrolepis). sablefish, longspine thornyheads (Sebastolobus altivelis). and
Dover soTe are conducted in depths ranging from 732 to T,280 m a'Vonq the
continental slope (PFMC 1980).
Midwater trawls harvest Pacific hake, widow rockf1sh(Sebastes
entomelas) and shortbelly rockfish (S. Jordani) over the continental shelf.'
The rapidly developing widow rockfTsh fishery is currently centered off
headlands such as Cape Blanco and Tillamook Head, on Heceta Bank, and over
the Astoria Canyon (Schafer 1981). The hake fishery takes fish which have
migrated into outer shelf and upper slope regions from spawning areas off
Southern California.
Longlines and traps are the primary gear types used in fishing for
sablefish at depths of 150 to 1,200 m on the outer shelf and slope, although
the species is also taken incidentally in bottom trawl fisheries (Low et
al., 1976).
Trawls and longline gear are also used for harvesting rockfishes and
lingcod (PFMC 1980).
Annual trawl landings along the Washington to California coast during
1970-1979 averaged 43,876 mt. The ex-vessel value in 1979 was over $19
million, about 75 percent of which was attributable to rockfishes, Dover
sole, petrale sole, English sole, and sablefish (PFMC 1980). Pacific cod
contribute about 10 to 15 percent to the annual trawl landings (Browning
1980).
Troll salmon fisheries generally occur in water depths of less than
200 m. In Washington, the majority of the catch is taken within 4.8 to 19.3
km of shore (PFMC 1978c). The two species which account for the majority of
the troll catch are chinook salmon (On c o r hy n c h u s- t s h a wy t s c h a) and coho
salmon (0. kisutch), the former species generally taken closer to shore than
the latter (PFMC 1978c). Small troll landings of pink salmon (_0. gorbuscha)
are also made during odd-numbered years. Nearly 4,000 vessels participated
in the Oregon troll fishery during 1980, landing 592,588 salmon valued at $8
million (PFMC 1981a). In Washington, 502,200 salmon were caught by
2,700-2,900 vessels (PFMC 1981a). No data are available concerning the
value of the 1980 fishery, although during 1971-1976, values ranged from
$3.7 to $13.8 million (PFMC 1978c).
The northwest Dungeness crab (Cancer magister) fishery is conducted in
shallow (<91 m) coastal waters from Destruction Island in Washington to
Cascade Head in Oregon and also from Newport southward (Figure 96). The
fishery is concentrated in areas where sand and mud substrates predominate
(PFMC 1979). Annual landings in Washington have averaged over 3.6 million
kg since 1951, and the average yearly value was $3 million during 1968-1976
(PFMC 1979). Comparable statistics for Oregon are 3.8 million kg with an
average value of $3.5 million (PFMC 1979).
The pink shrimp (Panda!us Jordani) fishery of the Pacific Northwest is
a relatively new development.This fishery is concentrated beyond 4.8 km
393
-------
GRAYS HARBOR
WILLAPA BAY
CAPE BLANCO %
vf
ABROOKIHGS
I"
Adapted from Figure 2, PFMC 1979,
Figure 96. Pacific Northwest Dungeness crab fishing areas.
394
-------
from shore in depths of 91 to 183 m and occasionally in depths as shallow as
64 m or as deep as 302 m over bottoms of green mud or a mixture of mud and
sand (PFMC 19815). Productive shrimp grounds are located from Destruction
Island in Washington to Newport, Oregon, and also off the central portion of
Oregon (Figures 97 and 98). In 1980, landings were 13.6 million kg valued
at $16.6 million in Oregon and 5.7 million kg worth $6.76 million in
Washington (PFMC 19816). The 1980 Oregon shrimp fleet included 222 vessels,
while in Washington, 37 boats were involved in this fishery (PFMC 1981b).
A sporadic fishery for albacore occurs off Washington and Oregon.
Albacore are present when warm water masses extend into the northeast
Pacific. Most albacore are taken between 80 - 241 km offshore during late
summer and early fall (i.e., July to October), but they are occasionally
caught as far as 482 km from shore (Browning 1980). It is estimated that up
to 4,000 vessels enter the albacore fishery on the Pacific coast in years
when large catches are predicted or when success in other fisheries is poor
(Browning 1980).
Currently, there are several fish species which remain underutilized by
the Pacific Northwest domestic fleet. Groundfish species such as skates
(Raja spp.), sharks (Squalus acanthias). Pacific hake, and some flatfishes
have either not gained market acceptance or processing costs remain
prohibitive. However, some of these species are sought by foreign
fisheries, and recently joint venture operations between U.S. and foreign
companies have begun exploiting some stocks such as hake.
Pelagic species also hold promise for fisheries development. Pacific
herring (Clupea harengus pall a si) are now fished within bays and estuaries
of Washington and Oregon. An experimental herring fishery off northern
Washington has recently been initiated to determine whether further
opportunities to harvest this resource exist (PFMC 1981c).
Pacific hake is another pelagic fish species which is currently
underutilized in the Pacific Northwest fisheries. Additional pelagic
species for which future fisheries may be developed include anchovies
(Engraulis mordax), Pacific mackerel (Scomber japonicus), pomfret (Brama
japonicaJT and squid (Loligo spp.).
In summary, current Pacific Northwest fisheries are conducted over
large areas of the continental shelf and slope from rather shallow coastal
depths of less than 36 m to deepwater (1,554 m) areas of the slope. Pelagic
fisheries occur at various distances from shore; the salmon troll fishery is
conducted .primarily within 19 km; the albacore fishery extends to 482 km.
Fisheries for Dungeness crab and pink shrimp are located in specific areas
off the coasts of Washington and Oregon in depths less than 183 m.
It is likely that in the future currently underutilized species will be
taken in areas of traditional fishery activities. Selection of a site for
the disposal of manganese nodule processing wastes should include
consideration of potential impacts on these fisheries.
395
-------
VANCOUVER ISLAND »•)$
*'"'. CAPE
"SHOALWATER
X^vliV,. COLUMBIA
RIVER
•• CAPE
y:FALCON
Adapted from Figure A3-1 , PFMC 1981b.
Figure 97. Washington pink shrimp fishing areas.
396
-------
ASTORIA
GARIBALDI
NEWPORT
WINCHESTER BAY
COOS BAY
BAM DON
\ PORT ORFORD
1 »GOLD BEACH
V;|\ BROOK INGS
WASHINGTON
OREGON
CALIFORNIA
Adapted from Figure A2-1, PFMC 1981b.
Figure 98. Oregon pink shrimp fishing areas.
397
-------
Fishery Biology--Since 48 spec'ies of groundfishes are taken in the
fisheries, only general aspects of their species biology will be addressed.
Most groundfishes spawn during winter or early spring (Table 55), with
a migration to deeper waters preceding spawning. The exception is lingcod,
which migrates into shallow rocky reef areas to spawn during October and
November. Rockfishes of the genus Sebastes are ovoviviparous (i.e., bearing
young alive) and many species form dense schools at certain times of the
year (PFMC 1980). Some rockfish species, such as splitnose (Sebastes
diploproa), stripetail (S. saxicola), sharpchin (S. zacentrus), snortspine
thornyhead (Sebastolobus alascanus), and redstrfpe (Sebastes proriger),
exhibit slow growth and relatively low productivity when compared to other
members of the group (PFMC 1980).
Oviparous (egg-laying) groundfish species demonstrate a range of
reproductive strategies. Eggs may be pelagic (e.g., Pacific hake),
semipelagic (initially demersal, subsequently pelagic) (e.g., Pacific
halibut), demersal without parental care (e.g., Pacific cod), or demersal
with parental care (e.g., lingcod) (Hart 1973).
The majority of groundfishes feed on macroplankton (e.g., euphausiids)
or benthic invertebrates. Many are opportunistic feeders, and some are
piscivores (Hart 1973).
Groundfishes occupy a wide range of habitats and depths. During
northerly feeding migrations from spawning areas offshore of southern
California in spring and summer, Pacific hake aggregate in midwater over the
outer shelf and upper slope areas of the northeastern Pacific. Adult
sablefish are generally found in the deeper waters of the continental slope
over mud-sand bottoms. Pacific cod, lingcod, and most flatfish species
occur predominantly on the shelf. However, Dover sole, rex sole, and
petrale sole frequently inhabit slope areas as well (PFMC 1980). Mud and
sand substrates appear to be the preferred habitat of flatfishes.
Table 55 lists the wide depth distributions of the rockfishes. These
range from the extreme depth of 1,554 m occupied by the shortspine
thornyhead to the nearshore areas inhabited by black rockfish (Sebastes
melanops). Generally, rockfishes occur over hard, rocky bottoms (PFMC
1980).
Inshore areas are important in the life cycles of several groundfish
species. The intertidal and nearshore areas serve as a nursery area for
many species (Hart 1973).
Most groundfish species do not display extensive migrations along the
coast. The exceptions are petrale sole, sablefish, and Pacific hake, which
are known to travel long distances (PFMC 1980).
Salmon life cycles involve both freshwater and marine components.
Chinook and coho salmon are the primary species caught in the ocean
fisheries.
398
-------
TABLE 55. SPAWNING PERIODS AND DEPTHS INHABITED BY
PRINCIPAL GROUNDFISH SPECIES OFF WASHINGTON AND OREGON3
Species
Roundfishes:
Lingcod (Ophiodon elongatus)
Pacific Cod {Gadus macrocephalus)
Pacific Hake (Whiting) (Merluccius productus)
Sablefish (Anoplopoma fimbria)
Rockfishes:
Black (Sebastes melanops)
Blue (S. mystinus)
Bocaccio (S. paucispinis)
Canary (S. pinniger)
Chili pepper (S. goodei }
Darkblotched TS. crameri)
pacific Ocean Perch (S. alutus)
Shortbelly (S. jordani)
Shortspine Tfibrnyhead (Sebastolobus alascanus)
Silvergray (Sebastes brevlspinis)
Splitnose (S. diploproa)
Stripetail TS. saxicoia)
Vermilion (S. mim'atus)
Widow (S. entomelas)
Yellowtail (S. flaviaus)
Flatfishes:
Arrowtooth Flounder (Atheresthes stomais)
Dover Sole (Microstomus pacificus)
English Sole (Parophrys vetulus)
Pacific Sanddab (Citharichthys soraiaus)
Petrale Sole (Eopsetta jordani)
Rex Sole (Glyptocephaius zachirus)
Starry Flounder (Platichthys stellatus)
Spawning Period
Oct-Nov
Jan-Mar
Jan-Apr
Nov-Apr
ND
Jan-Mar
Nov-Mar
Nov-Mar
Nov-Mar
Nov-Mar
Feb-Mar
Jan-Apr
Mar-May
Jun
Feb-Jul
Nov-Mar
Nov-Mar
ND
Nov-Mar
Dec-Mar
Nov-Mar
Nov-Mar
Jul-Sep
Nov-Mar
Jan-Jun
Nov-Feb
Depth Range
(m)
2-183
18-165
36-503
146-1,829
0-91
0-91
73-219
91-219
110-274
91-457
91-457
91-274
274-1,554
91-274
183-457
91-274
18-201
55-320
73-219
55-640
36-1,463
18-274
18-110
36-457
36-457
0-165
a Adapted from Table 12 of PFMC (1980).
ND = no data available.
399
-------
Young chinook salmon migrate into marine waters after spending
approximately 1 yr in freshwater (spring chinook) or less than a year (tan
Chinook) (Cumbow 1977). These species undertake wide-ranging migrations in
the northern Pacific Ocean, feeding on small fishes [e.g. sand lancj;
(Ammodytes hexapterus), eulachon (Thaleichthys pacificus). hernngj ana
crustaceans (Cumbow 1977; Hart 1973J":Chinook are known to venture out to
1,600 km offshore where they remain well below the surface (Hart 19/3). ine
chinook spawning migration to coastal rivers occurs in late spring and eariy
fall when the adults are 3 to 5 yr of age (Cumbow 1977). The adults feed on
fishes, particularly herring and sand lance. The Columbia River chinook
stock contributes substantially to the ocean troll fishery off Washington
and Oregon (Cumbow 1977).
Coho salmon migrate out of freshwater streams after a 1 yr residence
(Cumbow 1977). The marine migrations of juvenile coho are believed to be
less extensive than those undertaken by chinook (Cumbow 1977). Young coho
feed on squid, euphausiids, and fishes while at sea (Hart 1973). Adults
return primarily as 3 yr olds, with spawning migrations occurring in
September and October (Cumbow 1977). Mature coho also feed primarily on
herring and sand lance.
Pink, chum, and sockeye salmon also spend portions of their lives in
open ocean waters, but are not important in the ocean fisheries,
Dungeness crabs mate between February and June, with peak activity
occurring during April (PFMC 1979). Egg-bearing females occur in Washington
coastal waters during November to March and in Oregon during October to
March (PFMC 1979). Eggs hatch during the winter in shallow nearshore
waters.
Crab larvae are pelagic for approximately 3 to 5 mo while they drift
offshore during the winter to distances of as much as 96 km from shore (PFMC
1979). Coastal estuaries and bays are nursery areas for juvenile crabs.
Dungeness crabs are opportunistic feeders, taking primarily
crustaceans, clams, and fishes (PFMC 1979). Also included in the diet are
echinoderms, snails, and polychaetes. Preferred habitat for Dungeness crabs
is sand or sand and mud bottoms, although rock and gravel areas may also be
utilized (Browning 1980). Dungeness crabs are common to a depth of 91 m but
have also been taken in trawls fished at 274 m (PFMC 1979). Extensive
large-scale movements of Dungeness crabs between major fishing areas have
not been documented. However, seasonal onshore (spring-summer) and offshore
(fall-winter) migrations have been observed (PFMC 1979).
Pink shrimp are protandric hermaphroditee (male changing to female).
Mating occurs during September and October, with eggs hatching during late
March through early April (PFMC 1981b). Larvae undergo 11 to 13 zoeal
stages with an average duration of 6.8 days per stage (PFMC 1981b).
Although larvae are thought to be pelagic, they do not occur in surface
waters. Juvenile shrimp settle to the bottom beginning in July and
extending through the fall.
400
-------
Pink shrimp are primarily detritus feeders, utilizing the remains of
polychaete worms, sponges, diatoms, amphipods, and isopods (PFMC 19815)
During diel vertical migrations, shrimp prey on euphausiids and copepods.
Pink shrimp range in depth from 36 m to 457 m and occur over green mud
or mixed mud and sand substrates (PFMC 1981b). Maximum shrimp density is
believed to occur off central Oregon.
Young, immature albacore occur offshore of Washington and Oregon when
warm (14-21 C) water masses extend into the northeast Pacific (Browning
1980). In this area, near-surface feeding albacore take juvenile
rockfishes, sauries (Cololabis saira), anchovies, euphausiids, and squid
(Hart 1973; Browning 1980).AT waters cool, albacore return to the southern
latitudes of the North Pacific.
While the fishery for Pacific herring is currently conducted only in
the estuaries and bays of Washington and Oregon, important life stages occur
in offshore areas. In the fall, adults migrate from ocean feeding areas
into protected marine waters to spawn in winter and spring (PFMC 1981c).
After spawning, adults return to ocean feeding areas. Schooling juvenile
herring also move offshore to feed during March through July (PFMC 1981c).
In the ocean, herring are opportunistic feeders, taking zooplankton,
crustaceans, molluscs, cephalopods, larval fishes, and pelagic eggs (PFMC
1981c). Additional information on the offshore oceanic component of the
herring life cycle is unavailable.
Summary—Several aspects of the biology of the species which support
important fisheries should be considered in selecting a disposal site for
manganese nodule processing wastes. Demersal eggs may be particularly
susceptible to waste disposal, due both to potentially toxic substances and
to the physical effects of deposition which may smother the eggs. Pelagic
eggs and larvae may be affected by wastes in the water column, especially if
toxic components are present. Young rockfishes may be highly vulnerable to
wastes discharged in the water column. This is of particular concern for
species which are slow growing and have low productivity (e.g., splitnose
and sharpchin rockfishes).
Increased turbidity associated with the disposal of manganese nodule
processing wastes may affect schooling behavior and migratory activity.
Alteration of the plankton community due to waste discharges may reduce
the availability of food organisms upon which many species depend.
Accumulations of wastes on substrates may alter the preferred habitats
of demersal species such as flatfishes, Dungeness crabs, and pink shrimp.
These species' remain in almost continuous contact with the substrate and may
be susceptible to contamination from the wastes. Bioaccumulation of
potentially toxic substances (e.g., trace metals and other components of the
waste material) may induce diseases or other physiological abnormalities.
Additionally, if wastes affect food organisms of demersal species, stock
abundance may be altered.
401
-------
In summary, the biological characteristics of important fish species
warrant consideration in selecting an appropriate location for waste
disposal. Particular areas of critical importance to the life stages or
fishes (e.g., spawning, nursery, feeding) should be avoided. Also, specific
productive habitats such as the green mud pink shrimp beds and the sandy
Dungeness crab grounds warrant consideration of protection from potential
adverse effects of nodule processing wastes.
HAWAII
Physical Characteristics
Bathymetry-
Figure 99 presents the bathymetric contours along the axis of Puna
Canyon. The morphology of the adjacent Puna Ridge was surveyed using a
submersible by Fornari et al. (1979). The ridge is a submarine continuation
of the East Rift Zone of Kilauea volcano, and represents a principal locus
of submarine volcanic activity and a major outbuilding site for Kilauea.
The micromorphology consists of fresh lava pillows and cylinders with a lack
of interstitial sediments and benthic fauna. Subaqueous extrusions have
created narrow ridges oriented northeast-southwest. The ridge reportedly
consists entirely of basaltic lava outpourings similar to those of Kilauea
(Moore 1965). At the base of the ridge, lavas appear to "partially overlie
the volcaniclastic and possibly pelagic sediments which mantled the early
submarine slope of Mauna Loa" (Fornari et al., 1979).
Circulation Patterns—
The primary factors which influence current patterns in Hawaiian waters
are the West Wind Drift, tidal motions, and an anticyclonic gyre northeast
of the islands. Currents generally show strong tidal variations, frequently
including direction traversals over a tidal cycle, but are modified locally
by winds, internal wave motions, and other factors.
The small amount of literature on Hawaiian circulation patterns is
summarized in Laevastu et al ., 1964; Wyrtki et al., 1969; Patzert 1969;
Patzert et al., 1970; and Bathern 1976. Data on currents near the Island of
Hawaii are very limited. According to the Coast Pilot, along the northeast
coast, from Cape Kumukahi the eastern extremity, to Upolu Point the northern
extremity, the current sets generally to the northwest. A flood tidal
divergence reportedly occurs off Point Kumukahi, driving the northwesterly
flow. Laevastu et al. (1964) indicate that flow in this direction persists
even on the ebb tide beyond the 183 m (600 ft) depth contour.
In examining data available near proposed dredge spoil disposal sites
off of Hilo (Figure 100), it became apparent that previous oceanographic
measurements were made either within Hilo Bay or much farther offshore in
waters exceeding 3,000 m (10,000 ft) (Neighbor Island Consultants 1977). A
very limited amount of current data are available for dredge spoil disposal
sites 9 and 9B near Hilo Bay. At the Inner Hilo site 9 which is in 340 m
(1,115 ft) of water, two days of surface current measurements (drogue
402
-------
156° 155°
18°
155°
50
I NAUTICAL MILES
I I I I I I
0 50
CONTOUPS IN THOUSANDS OF FEET
KILOMETERS
ADAPTED FROM MOORE 1965
Figure 99. Bathymetry of the Puna Canyon,
403
-------
10'
155°00'
154°50'
HltO
HAWAII
I
58'
54'
50'
46'
19°42'
0
I
2 4
_l I NAUTICAL MILES
1 KILOMETERS
REFERENCE: EPA 1980C
I
4
8
Figure 100. Proposed and alternative dredged material
disposal sites.
404
-------
movements) indicated northwesterly flows at between 15 and 36 cm/sec. Upper
subsurface currents were highly variable with some tidal correlation.
Deeper currents decreased in magnitude but became more uniform in direction.
remaining between 338° and 20° of magnetic north. Surface currents had ISC'3
reversals in direction. At 15 m (50 ft), currents ranged from 15 to 57
cm/sec, decreasing toward the bottom to between 0 and 15 cm/sec. At site 9B
(Outer Hilo) which is in 329 m (1,080 ft) of water, surface drogue
measurements indicated a moderate west-southwesterly flow. Subsurface
currents of less than 26 cm/sec were generally oriented toward the
northwest. A tidal influence was evident on all records. The EIS for
Dredged Material Disposal Sites Designation (U.S. Environmental Protection
Agency 1980c) indicates that current speeds at these sites were 29, 19, 16,
and 11 cm/sec for meters at 15, 45, 183, and 340 m, respectively, with
deeper flows being towards the north.
Current measurements have also been made at nearby University of Hawaii
Station 212 off Alia Point to the north of Hilo in 210 m of water (Wyrtki et
al., 1969). August 3 through 15 recordings for a meter at a 30 m (98 ft)
depth indicated strong easterly (107° true) average current speeds of 32.7
cm/sec, with weak tidal currents superimposed.
Temperature, salinity, and density data for deepwater stations
northeast of the Island of Hawaii, shown in Figure 101, are presented in
Figure 102. Based on density data at adjacent stations (Figure 102),
geostrophic flows have been calculated for this general area as well (Figure
103).
Additional physical oceanographic data is currently being collected in
the Puna Canyon area in conjunction with a Sea Grant-sponsored geological
and geochemical assessment of proposed manganese nodule processing waste
disposal sites (John Wiltshire, personal communication, 1982). Measurements
include temperature, salinity, currents, light levels, and dissolved oxygen.
In January, the surface water temperatures were 25° C, decreasing to
22° C at 152 m (500 ft). At this point, a relatively sharp thermocline
occurred down to 243 m (800 ft). Beyond this depth, temperatures continued
to decrease, reaching 9° C at 426 m (1,400 ft).
Currents nearshore appear to be southward and can reportedly be as high
as 100 cm/sec. Deeper than 30 m (100 ft), currents decrease significantly,
becoming negligible. Offshore, from 15 to 35 km, northward surface currents
are weaker, being 25.7 cm/sec or less. Subsurface currents decrease quickly
as a function of depth, and tend to flow to the south.
Currents along the canyon axis at 426 m (1,400 ft) range from 0 to 13
cm/sec, and directionally are a function of tides, being upcanyon on a
rising tide and downcanyon on a falling tide. Bottom visibility is very
high due to the lack of any sediment, sources nearby, the closest drainage
being 50 km (28 mi) away.
405
-------
157° W
• AUGUST
O MARCH
156° W
155° W
154° W
t 517/14
^469/18
'517/13
21" N
20° N
19° N
STATION LOCATIONS FROM: NATIONAL OCEANIC DATA CENTER
Figure 101. Stations used in the calculation of
geostrophic currents.
406
-------
TEMPERATURE (°c)
0 5
SALINITY (ppt)
10 15 20 25 34 35
J 1 1
700-
800-
900-
1000-1-
24
DENSITY (at)
25 26
27
DATA FROM: National Oceanic Data Center
Figure 102. Temperature, salinity, and density at Station
469/18, 20°02'N, 154*44'W, March 17, 1953.
407
-------
VELOCITY (cm/sec)
0 5 10 15
VELOCITY (cm/sec)
-10 -505
VELOCITY (cm/sec)
--100
-P- -#200
4-300
040°T 220°T
500
STATIONS 517/13-
517/14
AUGUST 8-9, 1953
100
-•=- - 200
I
III
Q
040 °T
300
400
500
STATIONS 517/14-
517/15
AUGUST 9, 1953
220 °T
040 °T
700
800
STATIONS 469/17
469/18
MARCH 17, 1953
DATA FROM: National Oceanic Data Center
Figure 103. Geostrophic current profiles for waters
northeast of the Island of Hawaii.
408
-------
Representati ve Area
For the purpose of this project, the Puna Canyon area is discussed in
view of its proximity to an existing dredge material disposal site (9B). It
should be noted that site 9A in 2,103 m (6,900 ft) of water (Figure 100) was
relocated to site 98 due to intense commercial fishing at 9A (Neighbor
Island Consultants 1977).
Bi ol ogi cal Characteri sti cs
Open Ocean Environments off Hawaii —
In open ocean environments (> 4,000 m depth) of the tropical North
Pacific which are far removed from effects of proximity to the Hawaiian
islands, virtually all primary production is performed by phytoplankton.
Due to its dependence on sunlight, phytoplankton production is limited to
the upper (< 100 m usually) sunlit layers of the ocean. All other life in
these environments is dependent on the fixation of carbon by phytoplankton,
and hence production by the phytoplankton is essential to all higher trophic
levels. Phytoplankton production in the tropical Pacific is primarily
limited by the availability of nutrients (especially nitrogen as nitrate or
ammonium), which are typically in very low concentrations in the upper 100 m
(Anderson 1979). Nutrients are supplied to the phytoplankton either by
upward transport from deeper, nutrient-rich water, or by excretion of animal
wastes. As a consequence of the strong vertical stratification of the water
column, the supply of nutrients from deeper waters is slow. Regeneration of
nutrients by animals is important, but due to losses from the upper layers
(e.g., the sinking of fecal pellets), it cannot completely supply the
required nutrients. Since nutrients are in short supply, phytoplankton
production is quite low [100-200 mg C nT2 day'1; Chan and Anderson (1981)],
and consequently, production at all higher trophic levels is also low,
relative to coastal and nearshore areas.
One result of the supply of nutrients from deeper waters is that
phytoplankton biomass is often greater deep in the euphotic zone than at
shallower depths. Venrick et al . (1973 reported, for instance, that a
subsurface maximum in chlorophyll a concentration (a commonly-used measure
of phytoplankton standing stock) was typically found at depths receiving
only 0.1-1 percent of the incident light at the surface, and that more than
s?k a:
s
the "resultant sinking of diatoms (Vennck et al., 1973).
Oceanic phytoplankton are primarily consumed by zoopl ^™> m*n/ °f
409
-------
Pacific, perhaps best represented by the calanoid copepods, of which there
are dozens of species in this environment. While many zooplankton species
inhabit the euphotic zone, others perform limited (< 200 m) die! vertical
migrations which bring them into the euphotic zone only at nignt.
Zooplankton occur at all depths throughout the water column in the tropical
Pacific, but those occurring below about 200 m are almost exclusively
carnivores and/or detritivores.
All animals larger than zooplankton which inhabit the water column are
classified as nekton. This group includes not only fishes, but squid,
shrimp, whales, dolphins, etc. Common fishes occurring near the surface in
tropical Pacific waters include flying fishes, dolphin (manimani)
(Coryphaena hippurus). yellowfin and skipjack tunas (Thunnus albacares and
Euthynnus pelamis), marl ins, and barracuda (Sphyraena spp.) (Gosline and
Brock 1960). Other large pelagic fish species, such as albacore (Thunnus
alalunga), bigeye tuna (J. obesus), and broadbill swordfish (Xiphias
gladius), occur very infrequently near the surface, and more typically
"inhabit" depths of 37 m or more (Gosline and Brock 1960). Marine mammals of
the tropical Pacific include various whale and dolphin species. The larger
nekton species are generally strong swimmers which range over large areas of
the oceans and are not restricted to a single geographic area. Because
oceanic primary production is low in the tropical Pacific, and because these
large species of nekton are a number of trophic levels removed from the
primary producers, they are quite rare considering the total expanse of the
oceans. Nevertheless, certain species (e.g., tunas, whales, dolphins) are
known to school, and consequently they may be abundant in a given area for a
short period of time.
Many small nektonic species in the tropical Pacific inhabit mesopelagic
depths (100-1,000 m), and many of these perform die! vertical migrations
into the epipelagic zone (< 100 m) [cf. Clarke (1973, 1974); Clarke and
Wagner (1976)]. While these species are widespread, individuals of these
species are not as wide-ranging as those of the larger, epipelagic species.
With the exception of flying fishes, which attach their eggs to
floating objects, all other pelagic fish species in these environments lay
and fertilize their eggs in the sea itself (Gosline and Brock 1960). The
eggs and larvae, collectively referred to as ichthyoplankton, are carried
about by the currents. The larvae are typically very small, and dependent
on plankton for food.
Another important, although temporary, component of the open pelagic
community is the young of reef and inshore fishes. While in some cases the
occurrence of these young fishes in the epipelagic zone of the open sea may
be a chance effect of currents carrying small fishes with limited swimming
abilities away from their normal inshore habitat, in other cases, the young
of certain species (e.g., surgeonfishes, goatfishes, eels) may possess
certain characteristics which represent adaptations to an open sea existence
(Gosline and Brock 1960).
Benthic animals, including both organisms living in and on the sea
floor and demersal organisms swimming just above the sea floor, are entirely
410
-------
dependent on the production of organic matter in the overlying waters.
Organic matter is transported to the deep sea benthos by sinking carcasses,
fecal material, exoskeletons, and detritus, and by the vertical migrations
of some nektonic species. Since the supply of organic matter is inversely
related to the distance from the surface, and since primary production in
the tropical Pacific is very low, deep benthic life there is sparse by
comparison to benthic communities in shallow, nearshore areas. Very little
is known about the life histories, reproductive strategies, modes of
feeding, etc. of the deep-sea benthos in the tropical Pacific. Suffice it
to say: however, that these communities are ill-adapted to environmental
perturbations of any kind, since temperature, salinity, chemical
concentrations, rate of sedimentation, etc. are virtually constant at any
given location. Deep-sea benthic organisms are typically either large,
mobile scavengers able to locate and utilize large organic "windfalls" such
as carcasses, or very small (less than a few millimeters in length) and not
very mobile organisms living on or in the sediments.
In a study of the deep-sea benthos at a site underlying the North
Pacific Central Water Mass north of Hawaii, Messier and Jumars (1974)
reported that macrofaunal abundances ranged from only 84-160 individuals/m2,
with polychaetes dominant. Other abundant taxa included tanaids, bivalves,
and isopods. Meiofaunal abundances were at least 1.5-3.9 times larger than
those of macrofauna, with nematodes dominant. Other abundant taxa included
foraminifera and xenophyophoridans, although separating living from dead
individuals of each was impossible. The primary mode of feeding for the
benthic fauna appeared to be deposit feeding. Diversity was high, but the
abundances of individual species were very low.
Shelf Environments of Hawaii —
Due to the relatively narrow shelves surrounding the Hawaiian islands,
the available shelf environment is small. Nevertheless, there are some
important differences between the shelf communities and those in either open
ocean or nearshore environments.
As in open ocean environments, virtually all of the primary production
in the shelf communities surrounding the Hawaiian islands is attributable to
phytoplankton. Unlike open ocean waters, however, where both phytoplankton
standing stock and primary production are typically quite low, phytoplankton
communities near the Hawaiian islands are apparently influenced by a
so-called "island mass effect," which increases both the phytoplankton
production and standing stock, especially on the leeward side of the
islands. Gilmartin and Revelante (1974) reported, for instance, that
phytoplankton standing stocks (as measured by chlorophyll _a concentrations)
at stations less than 1 km from the coast were approximately double those in
offshore waters, while rates of primary production were 4-5 times higher at
these stations than in offshore areas. Whereas phytoplankton in offshore
open ocean areas were apparently nutrient limited, those at stations less
than 1 km from the coast did not appear to be nutrient limited. Gilmartin
and Revelante (1974) attributed this apparent "island mass effect to
turbulence and vertical mixing in the channels between the islands.
Although such an effect would be expected on the leeward side of the
411
-------
Hawaiian islands (i.e., to the west of the islands, since the prevailing
ocean currents are towards the west), due to tidal reversals of the currents
in the island channels, there may be a similar, albeit less pronounced,
effect on the windward (i.e., eastern) side of the islands. Gilmartin and
Revelante (1974) noted an increased proportion of net phytoplankton
(including a number of neritic diatom species) and a decreased proportion or
nanoplankton at stations close to shore, relative to those in offshore
waters.
Due to the narrowness of the Hawaiian shelves, it is unlikely that a
resident zooplankton community would develop there. Instead, it is more
likely that zoopl ankton present in this environment would be composed of a
mixture of oceanic and neritic species.
In inshore Hawaiian waters at depths less than 30 m, the pelagic fish
community consists of both some of those species listed previously which are
more typically found farther offshore, and other species which are to a
major extent restricted to this area [e.g., bonito (Euthynnus yaito), bigeye
scad (Selar crumenoptalmus). mackerel scad (Decapterus spp.); cf. Gosline
and Brock (I960)].
Nearshore waters of the Hawaiian islands represent important habitat
for the endangered humpback whale (Megaptera novaeangliae). These whales,
which spend the summers in subarctic waters and overwinter near Hawaii, are
commonly found in nearshore waters around the island of Hawaii, especially
off the northwest and southern coasts (cf. U.S. EPA, 1980c). Humpback
whales are present in Hawaiian waters from November to May, and calving
occurs mainly between January and March. Other marine mammals occur in
Hawaiian nearshore waters, but none apparently have critical habitat
requirements around the island of Hawaii.
Due to the volcanic origin of the Hawaiian islands, there is a
precipitous increase in depth with distance offshore, and consequently there
is not an extensive shelf benthic community as found on the shelves
surrounding the continents. Benthic animals at these depths (< 200 m) may
be detritivores, suspension feeders, or carnivores. The shallower portions
of this habitat grade into the nearshore environment.
Some important commercial species occur at depths greater than 100 m
around the Hawaiian islands. Included are the precious corals (e.g., black
coral, gold coral, and pink coral), which feed on sinking detrital material,
and various crabs, shrimps, and demersal fish species [e.g., groupers
(Epinephelus quernus ), red (Aphareus ruti1ans , Etel is marshi , and
E. carbunculus) and pi n k (Pristipornoides filamenfosus and P. sieboldji)
snappers, amberjacks (SerioTa~dumerilii)]; cf. Hawaii Department: of Land and
Natural Resources (HDLNR) (198UJI
Nearshore Environments around Hawaii —
The nature of the nearshore environments around Hawaii is largely
determined by the position of the coast relative to the prevailing winds and
currents. Hence, the windward (or eastern) sides of the islands have
412
-------
cirfoc l£ ?h !! nearshore environments than do the leeward (or western)
ilrrV.c^ • "indwar^nside of the island of Hawaii, for instance, depth
ilwirnn q. " paP1dly with di stance from shore, and the nearshore
environment can best be described as a high-energy environment.
Consequently, the growth of coral is very limited there. On the leeward
side of Hawaii, however, the coastline is more protected, and extensive
coral reefs have developed.
As in waters slightly farther offshore, the phytoplankton found in the
nearshore environment are not likely to be nutrient-limited. With good
vertical mixing and an adequate supply of nutrients, both phytoplankton
production and standing stock are likely to be higher here than in offshore
regions. In addition to the primary production by phytoplankton, however,
is the contribution of benthic algae.
Unlike some other coral reef communities, where coelenterate corals are
the dominant reef builders, crustose coralline algae are much more important
in this role in Hawaiian waters (Littler 1973). Benthic algae and aquatic
vascular plants may be very abundant in tide pools or anchialine pools
[i.e., shoreline pools without surface connection to the sea but having
waters of measurable salinity (0.5-30 percent), and showing tidal
fluctuations; cf. Gosline and Brock (1960), Brock and Brock (1974)]. Hence,
there is an appreciable contribution to nearshore primary productivity by
benthic plants.
Zooplankton are still the primary consumers of phytoplankton in the
nearshore environment. There are a variety of benthic organisms which
consume benthic plants.
The community of fishes and benthic organisms inhabiting coral reef
environments should be considered as a whole. Both fishes and benthic
organisms are influenced by physical factors (e.g., wave exposure, salinity,
turbidity), they interact in ways which structure their environment, and
each affects the distribution of the other.
Whereas large portions of the coasts of the other Hawaiian islands are
fringed by coral reefs, only a small section of the northwest coast of
Hawaii has a fringing reef (Devaney and El dredge 1977). The presence of a
fringing reef at this location is likely due to its leeward position on the
island with respect to the dominant, wi nds and waves. However, the
semi-protected nature of the area north of Keahole Point on the Kona coast
of Hawaii may also be the reason that coral growth is less vigorous there
than in areas south of Keahole Point. Gosline and Brock (1960) felt that
this might be attributed to occasional occurrences of muddy water there as
well as fine sediments in some of the bottom deposits.
Following a biological reconnaissance of the northern Kona coast of
Hawaii, Brock and Brock (1974) divided the nearshore environment there into
three zones: the intertidal zone, a subtidal "A" zone, and a subtidal "B"
zone.
413
-------
The intertidal zone extends from the highest tidepools down to the
level of the lowest low tides. Since tides in Hawaii are of limited
amplitude (< 1 m) the vertical extent of this zone is small. The intertidai
zone is subject to heavy surf and is consequently well supplied with oxygen
and food. Sixty-eight species of invertebrates were identified from this
zone, including mollusks, crustaceans, echinoderms, and cnidarians including
some corals (Brock and Brock 1974). Sea urchins and snails were abundant
where wave action was strong, while corals, sea cucumbers, rock oysters,
hermit crabs, encrusting sponges, tube worms, and brittle stars were common
in the more protected tidepools. The fishes found in the intertidal zone
were for the most part juveniles of many species which as adults are found
in deeper water farther from shore (Brock and Brock 1974).
One curious feature of certain nearshore areas on the island of Hawaii
is the presence of a fresh water lens overlying more saline seawater. Since
the lava rock is porous, fresh water from the land percolates through it and
at the land-water interface this fresh water may mix with the seawater and
appreciably lower the salinity (Brock and Brock 1974). This subtidal zone
"A" includes both coastal ponds with connections to the sea and the
aforementioned anchialine ponds without surface connections to the sea.
Organisms found in subtidal zone "A" are euryhaline (i.e., they can
withstand extended periods of lowered salinity). The invertebrate fauna
includes an encrusting alcyonarian, polychaetes, attached bivalves, and
crustaceans (e.g., some species of shrimps, crabs, and amphipods).
Echinoderms are conspicuously absent, and are probably not capable of
tolerating the reduced salinity (Br-ock and Brock 1974). Only a few species
of fishes were found in this zone.
In areas with little or no freshwater influence, the subtidal zone "B"
extends from just below the intertidal to greater depths. In areas where
freshwater is mixing in the shallows, subtidal zone "B" begins at a depth
below the effect of this mixing. While many invertebrates found in the
intertidal occur in increased abundance in subtidal zone "B", the region was
dominated visually by corals, while other invertebrates were hidden within
the corals or in the surrounding areas. Brock and Brock (1974) identified
95 species of invertebrates and 137 fish species from this habitat.
Sandy beaches occur along some areas of the coast. The resident
organisms on these beaches are influenced by the particle size of the sand,
the slope of the beach, and the color of the sand (which is usually black on
the island of Hawaii). The beaches may be inhabited by amphipods, isopods,
ghost crabs, mole crabs, and various polychaetes and mollusks (HDLNR 1980).
In some locations along the Kona coast of the island of Hawaii, the
remains of ancient lava flows extend offshore as a solid pavement of exposed
basalt, containing many cracks and crevices which provide shelter for a
variety of organisms. In such habitats, the maximum water depth is only 3-4
m. The predominant benthic organism in this shallow, reef-flat habitat is
the coral, Pocillopora meandrina, which grows as isolated heads 10-50 cm
wide (Hobson 1974).Other coral species may be interspersed among the
P. meandrina, and various sea urchins may also be present (Devaney and
ndredge 1977). Since this type of habitat is generally found where wave
414
-------
action is high, the organisms living there must be able to tolerate
considerable water movement and wave shock. Among the fishes found in such
areas, for instance, species of wrasse and damsel fish apparently take refuge
in small holes and cracks in the rock, while surgeonfishes seek refuge in
open water areas farther from shore (Gosline and Brock I960).
In other areas of the Kona coast having exposed shorelines, basalt
boulders cover the bottom from shore to depths of about 15 m. Various algae
and corals, mostly encrusting varieties, are found on the surfaces of these
boulders (Hobson 1974). While the upper part of this habitat is often swept
by a strong surge, the lower portion (at depths > 12 m) is calmer and grades
into fields of the fingerlike coral, Porites compressus (Hobson 1974).
Fishes within the boulder areas must be capable of tolerating the strong
wave surge there.
At the offshore edge of the shallow reef flats, and at other locations
along the shore, a sheer basalt face is found which drops precipitously to
depths of 10-15 m. This reef-face produces a variety of habitats, ranging
from an area dominated by wave surge and therefore resembling the reef-flat,
to an assemblage of boulders at the base of the reef face, having a
community of encrusting corals and algae. Planktivorous fishes tend to
congregate adjacent to such reef faces (Hobson 1974).
Beyond depths of approximately 25 m, the sea floor increases rapidly in
depth with increasing distance from shore. Near the rim of this drop off,
the sea floor is generally overgrown with the fingerlike form of Porites
compressus, interspersed with massive heads of _P. pukoensis, bare basalt
boulders, and sand patches. Planktivorous fishes are especially abundant in
the overlying waters (Hobson 1974).
Different coral assemblages dominate in areas protected from large
ocean waves. Along the Kona coast at depths of 2-12 m, the coral Porites
pukoensis grows in a variety of massive formations. If there is increased
exposure to waves, however, _P. pukoensis is replaced by _P. compressus as the
dominant coral. Habitats dominated by one or the other of these forms are
distinct from one another in many of the other resident organisms as well
(Hobson 1974). The resident organisms may include slate pencil urchins,
heart urchins, cowries and other mollusks, soft corals, filamentous algae,
crustose coralline algae, bryozoans, and sponges (HDLNR 1980). This
community is particularly vulnerable to anthropogenic alterations such as
reductions in visibility associated with wastewater discharges, increased
sedimentation, and freshwater flooding. It is important to note that the
fish fauna of these coral-rich habitats varies considerably between day and
night. In particular, fishes inhabiting deeper waters by day may move into
the shallower coral reef habitat at night (Hobson 1974).
While the preceding generalized discussion of coral reef habitats on
the Kona coast of the island of Hawaii is based largely on Hobson's (1974)
study of the southern coast, no major differences would be expected between
this area and the northern Kona coast. Similarly, the preceding description
of the intertidal and shallow subtidal habitats is based largely on the work
of Brock and Brock (1974) on the northern Kona coast. In general terms,
that description should apply as well to the southern Kona coast.
415
-------
As previously mentioned, the eastern shoreline of the island of Hawaii
is considerably different from the Kona coast. The prevailing winds,
currents, and waves all impinge upon the eastern shoreline, and consequently
there is little coral development there. The bottom drops off rapidly in
most areas, and in that respect would be expected to be somewhat similar to
the reef-face environment on the Kona coast, which was described above.
Certainly a greater diversity of both benthic animals and the associated
fishes would be expected along the Kona coast than along the windward side
of the island of Hawaii. Invertebrates along the eastern shoreline or
Hawaii are those capable of seeking refuge in rock crevices. The fishes
inhabiting this area are strong swimmers tolerant of strong wave surges.
Hawaiian Fisheries —
Hawaiian fisheries primarily occur within 32 km of the coast. Several
factors are responsible for having restricted the fisheries to the nearby
coastal waters. These include the narrowness of the insular shelf, the
rather small size of Hawaiian fishing vessels, the lack of good harbors and
facilities, the need for live tuna baitfish which cannot be transported long
distances, and the markets which depend primarily on fresh seafood products
(HDLNR 1979).
The island of Hawaii supports an expanding fishing industry. Hilo and
Kona are the main commercial fishing ports (HDLNR 1979). The largest sport
fishery in the state is also centered in Kona, which annually hosts a number
of billfish tournaments. Around the island of Hawaii, tuna (Thunnus spp.)
fisheries are the most important, followed by those for limpets (opihi)
(Cellana spp.), wahoo (Acanthocybium solandri), scads (Selar crumenoptalmus,
Decapterus spp.), and blue m a r 11ri'(Ma k aTra n i g r i can s). Landings on tne
island of Hawaii in 1977 totaled 1.2 mi 11 ion kg, with a value of $2.3
million (HDLNR 1980). During 1978-1979, 712 commercial fishing licenses
were issued on the island and 369 vessels participated in the various
fisheries (HDLNR 1980). Handlines and trolling are the major fishing
methods employed on the island of Hawaii.
Fishing Areas--The night tuna handline or ikashibi fishery around the
island of Hawaii has been rapidly developing since the early 1970s (HDLNR
1979, Ikehara 1981). In 1977, 40 Hilo vessels participated in this fishery,
while 10 boats fished out of Kona (HDLNR 1979). Gross revenues to fishermen
from this fishery exceeded $2.9 million in 1980 (Ikehara 1981).
Ikashibi fishing areas are located 24-80 km offshore of Hilo and Kona.
The best fishing occurs at the steeply sloping edge of the shelf; about 400
m depth in the Hilo area and 200 m in the Kona area (HDLNR 1979). Handlines
are fished at depths of 23 to 60 m. Yellowfin tuna (ahi) (Thunnus
albacares) is the predominant species taken in this fishery, fol I owed b'y
albacore (ahipalaha) (T. alalunga). and bigeye tuna (T. obesus) (Ikehara
1981). Several billfisTi species (istiophorids, Xiphias gTadius) and dolphin
(mahimahi) (Coryphaena hippurus) are also caught in this fishery. These
species as well as wahoo (ono) are also taken in the day handline, surface
troll, and flagline (longline) fisheries conducted within 32 km of the Kona
coast (HDLNR 1979).
416
-------
Deep-sea handlining for a number of bottomfish species around the
island of Hawaii is concentrated in rocky areas having dropoffs, pinnacles,
and depressions in depths ranging from 55 to 274m (Ralston 1979). During
1966-1977, the island of Hawaii accounted for nearly 19 percent of the
bottomfish landed in the state (Ralston 1979). Important species for the
island include the red snappers [lehi (Aphareus rutilans), ehu (Etelis
marshi). pnaga (E. carbuncul us)], pink snappers [kalikali (Pristopomoides
sieboldii), opakapaka (P. fi 1 amentosus )] , gray snapper (uku) (Aprion
virescens), blueline snapper (taape) (Lutjanus kasmira), amberjack (kahala)
(Sen"ola dumerilii), and jack crevalle (ulua) (11 spp. of carangids).
Most fishing for bottomfishes occurs in waters 3.2 to 32 km offshore,
except for the catch of blueline snapper and carangid species, about half of
which is taken closer to shore (Ralston 1979). The average annual reported
catch of bottomfishes during 1973-1977 was 5,729 kg and 3,460 kg for waters
adjacent to Kona and Hilo, respectively (HDLNR 1980).
The midwater handline and net fisheries for bigeye scad (akule) (Selar
crumenoptalmus) and mackerel scad (opelu) (Decapterus spp.) are important in
the nearshore ^waters of the island of HawaTTT Most fishing occurs within
3.2 km of shore in 27-107 m depths (HDLNR 1979). This island typically
accounts for 3 to 8 percent of the state's annual catch of bigeye scad;
however, during some years the percentage increases to 10 to 18 percent
(HDLNR 1979). The majority of the state's catch of mackerel scad (90
percent in 1977) is taken in the nearshore waters off the Kona coast (HDLNR
1979). A local fishery for this species is also conducted near Hilo.
Table 56 lists the major species taken in statistical areas adjacent to
Hilo and Kona during 1977. The inshore area encompasses the waters to the
edge of the outer reef, approximately 3.2 km out from the coast. The
offshore region extends from the reef edge out to 32 km. Inshore fishes
landed in 1977 include amberjack, jack crevalle, and red snapper (Etelis
carbunculus). Shallow water schooling species such as bigeye scad, mackerel
scad, and mullet ('ama 'ama) (Mugil cephalus) are also taken inshore by nets
and hook and line. Apparently, yellowfin tuna are also caught in the
nearshore zone. Fishes caught in the offshore waters are primarily tunas
and wahoo. During 1978, the offshore area of Kona produced the largest
catches of yellowfin tuna (^317,515 kg), blue marl in (^90,718 kg), and wahoo
(^18,144 kg) in the state (HDLNR 1980).
A small-scale crab fishery is conducted off the Kona coast. The Kona
crab (Ranina ranina) is harvested in certain areas on sandy bottoms at
depths of 27 to 91 m.
Precious corals support a minor commercial industry on the island of
Hawaii. Pink coral (Coral1iurn recundum) occurs off Keahole Point on the
Kona coast. The deepwater (400 m) bed, which occurs on a hard substrate
free of sediment, is estimated to cover an area of 0.24 km^ (HDLNR 1979).
Black coral (Antipathes dichotoma, A. grandis. A. ulex) is collected at
shallower depths (40 to 80 m) within 4.8 km of shore. Small black coral
beds are located off South Point and Mahukona on the island of Hawaii (Poh
417
-------
TABLE 56. MAJOR FISH SPECIES CAUGHT IN WATERS ADJACENT TO
HILO AND KONA, ISLAND OF HAWAII, 1977a
00
Area 1
Hilo
Inshore0
(HDFG Block 105) yellowfin tuna
Offshored
(HDFG Block 125) yellowfin tuna
Kona
Inshore
(HDFG Block 101) mackerel scad
Offshore
(HDFG Block 121) yellowfin tuna
Species Rank Based on Total Pounds Landed
2345
bigeye scad mullet amberjack red snapper
skipjack tuna albacore tuna bigeye tuna wahoo
yellowfin tuna bigeye scad wahoo jack crevalle
blue marl in mackerel scad wahoo bigeye tuna
Adapted from Table 6.2 of HDLNR (1980).
(1 = largest catch, 5 = smallest catch).
From shore to edge of outer reef ^3.2 km.
From edge of reef out to 32 km.
-------
' ?rN? ^ uPa Se bSd, ]-S alSO found off the northeastern coast of
hf« ni( H", 19 J'u Howe.ver> ,Gri99 (1974) notes that many areas remain to
be explored around Hawaii, and thus additional commercial quantities of
black coral may exist.
It is unlikely that major new fisheries will develop within 32 km of
the coast of the island of Hawaii since many of the available fish stocks
are already heavily exploited. However, as newer, more sophisticated
vessels enter the fleets, tuna fisheries, which also exploit billfish, may
develop further offshore.
Currently, underutilized stocks include sharks and shrimp. Apparently,
market resistance is the major impediment to the shark fishery. Surveys
have indicated an abundant shark resource along the insular shelves of the
main Hawaiian islands at depths of less than 91 m (HDLNR 1979). Major
species include sandbar shark (Carcharhinus milberti), tiger shark
(Galeocerdo cavieri), grey reef shark (C. amblyrhynchos), and Galapagos
shark (C. galapagensis ). Oceanic sharks such as white-tipped
(.£• 1 ongTmanus), bl ue fPri onace gl auca ), and mako (Isurus spp.) are
currently being harvested in the longline tuna and bill fish fisheries.
Incidental catches of demersal sharks are also made in the bottomfisheries
at depths of less than 27 m. It is estimated that shark landings for the
Hawaiian islands could potentially range from 240,000 to 1,070,000 kg
annually (HDLNR 1979).
The extent of Hawaiian shrimp resources remains uncertain; however,
shrimp are believed to be widely distributed in the water surrounding the
islands (HDLNR 1979). Three caridean shrimp species (Heterocarpus ensifer,
H. laevigatus, Pleisioneka sp.) appear to be most abundant at depths of
274-640 m over a variety of bottom types. H. laevigatus occurs primarily
over steep, rough terrain. The penaeid shrimp~~[Penaeus marginatus) is a
somewhat shallower species, occurring as subadults at depths of 64 m and
gradually moving to deeper waters of 237 m as they mature (HDLNR 1979).
In summary, there are important inshore and offshore fisheries
conducted in waters adjacent to the ports of Hilo and Kona on the island of
Hawaii. Because Kona is located on the leeward side of the island, its
fisheries are more diversified and its landings are greater than at Hilo,
where rough waters limit fishing activity. Most fisheries occur within 32
km of the coast; bottomfisheries are conducted in areas where rocky habitats
are prevalent and tuna fisheries are conducted at the edge of the insular
shelf. Selection of a site for the disposal of manganese nodule processing
wastes should certainly include consideration of possible effects on these
productive fishing areas.
Fishery Biology—Four tuna species support fisheries in the waters of
the island of Hawaii. Since they are wide-ranging oceanic fish, little
detailed information is available concerning life histories of the
individual species. The pelagic tuna eggs hatch within 48 hours or less,
and the larval stages persist for 2 to 3 weeks (Wise 1974).
419
-------
Skipjack tuna spawn throughout the year in tropical waters, and from
late spring to early fall in subtropical areas. Spawning is primarily
influenced by warm water temperatures and occurs in the central Pacific
between longitude 150° E and 150° W (HDLNR 1979). Skipjack larvae occur in
surface waters where temperatures are above 24° C and are widely distributed
in the Pacific. In the Western and Central Pacific, larvae occur west or
longitude 145° W between latitudes 20° N and 10° S, and east of longitude
145° W between latitudes 10° N and 10° S (HDLNR 1979).
Yellowfin tuna and albacore have peak spawning periods during June and
July. Hawaii is the easternmost spawning area of the North Pacific albacore
stock. Yellowfin larvae are abundant in oceanic waters during May and June
but absent during November to March (HDLNR 1979).
No data are available concerning the seasonality of bigeye tuna
spawning. Larvae of this species are found less regularly than yellowfin or
skipjack tunas, and appear to be associated with land masses, since they are
seldom encountered in oceanic areas (HDLNR 1979).
The four tuna species display specific depth preferences. Skipjack
tuna are primarily surface dwellers, while yellowfin tuna occur in the upper
137 m of the water column. Albacore are common at depths ranging from 137
to 183 m, while bigeye tuna are the deepest dwelling of the four species,
occurring between 183 and 274 m (HDLNR 1979).
Wide-ranging migrations are an important component in tuna life cycles.
Skipjack migrations have been intensively studied, revealing a roughly
circular migratory pattern, clockwise in the North Pacific and
counterclockwise in the South Pacific (HDLNR 1979). Of primary importance
in the vicinity of the Hawaiian Islands are the short-term movements and
behavior of small (< 2.7 kg) skipjack tuna. These fish appear to aggregate
in schools in specific areas during the day, a behavior which may be
associated with feeding (HDLNR 1979). At night the school disperses, only
to reform by sunrise in the same locale.
Blue marl in and striped marl in (Tetrapturus audax) are the two major
billfish species taken incidentally in the tuna fisherfes. As with tunas,
little specific information is available concerning the life cycles of these
oceanic fish. Both species are highly fecund, pelagic spawners. Blue
marl in spawn throughout the year in tropical and subtropical waters, while
striped marl in spawning occurs during the early summer (WPFMC 1981). Blue
marl in larvae are distributed in warm (26-29° C) surface waters.
The distribution of blue marl in is influenced by the abundance of
skipjack tuna, its principal prey. Other forage items include dolphin,
squid, mackerel scad, and the pelagic juveniles of inshore reef fishes
(HDLNR 1979). Striped marlin feed opportunistically on squid and a variety
of pelagic fishes including scombrids, anchovies, and sardines.
Striped marlin typically occur in surface waters where temperatures
range from 20-25° C, but also are found to depths of 183 m.
420
-------
Little information is available concerning the life histories of the
lutjanid and carangid species which support Hawaiian bottomfisheries. It is
known that these species occur in areas of high relief such as rocky ledges
pinnacles, and in depressions (Ralston 1979). Depth distributions for the
bottomfish species are shown in Table 57. In some cases, this is the limit
of knowledge concerning a particular species.
The red snapper (Etelis carbunculus) and the two pink snappers are
believed to be shoaling species (Ralston 1979).
Bpttomfishes utilize a wide variety of prey items, including larval and
juvenile fishes, and invertebrates (e.g., copepods, polychaetes,
cephalopods, mollusks, crustaceans). Spawning periods for the gray and pink
snappers, amberjack, and the carangid species are believed to be during the
summer months. It is speculated that gray snapper and amberjack may be
migratory; however, movement patterns are poorly understood (Ralston 1979).
Bigeye scad and mackerel scad spawning occurs over an extended period
from late winter-early spring through August (HDLNR 1979). Mackerel scad
spawn in relatively shallow (i.e., 18-91 m) inshore areas (HDLNR 1979).
Schools of bigeye scad spawn over flat, sandy bottom areas at depths less
than 22m (Gosline and Brock 1960). Both species produce buoyant, pelagic
eggs. The diets of these species include planktonic organisms (e.g.,
amphipods, crab megalops, fish larvae) and small fishes. Mature scad occur
in schools in shallow nearshore waters. Juveniles remain offshore however,
as far as 129 km from the coast (HDLNR 1979).
Little information is available concerning the biology of precious pink
coral. This species is found at depths of about 400 m only on hard
substrates which are constantly swept clean of sediment by strong currents
(HDLNR 1979).
Black coral species are found in habitats which include an irregular
calcium carbonate substrate associated with overhangs, caves, ledges, and
dropoffs (Grigg 1965). Grigg (1965) postulates that their larvae are
negatively phototactic and will not settle or survive unless light
penetration is less than 25 percent of surface light. Adult colonies
apparently can withstand light intensities to 60 percent of incident surface
light (Grigg 1965). Current speeds of 25 to 100 cm/s appear to be optimal
for black coral growth (Grigg 1965). However, colonies are limited in
high-energy wave surge zones. Suspended particulates increase the
abrasiveness of currents and also reduce the habitable range of black coral
(Grigg 1965). The food of black coral includes amphipods and copepods
(Grigg 1965).
Life histories of Hawaiian deepwater shrimp species are not well known.
Year-round spawning has been suggested (HDLNR 1979). Heterocarpus ensifer
is abundant between 274-457 m depth in water temperatures of 8-10° C.
H. laevigatus occurs somewhat deeper (457-640 m) on steep rough bottoms
"where temperatures range from 6-9° C.
421
-------
TABLE 57. DEPTH DISTRIBUTIONS OF HAWAIIAN BOTTOMFISHES3
Species
Depth Distribution (m)
Red snappers:
Aphareus rutilans
Etells marshi
E. carbunculus
Pink snappers:
Pristipornoides filamentosus
P. sieboldli
Gray snapper (Aprion virescens)
Blueline snapper (Lutjanus kasmira)
Snapper (Tropidinius zonatus)
Grouper (Epinephelus quernus)
Amberjack (Seriola dumerilii)
110-183
183-293
201-293
73-146
146-256
inshore-73
91
146-219
128-219
46-229
Data from Ralston (1979).
422
-------
Summary-Overall, the biology of most commercially-important Hawaiian
species is not well understood. Given this lack of knowledge of critical
nre stages, it is in most cases difficult to predict the potential impacts
of manganese nodule processing waste disposal on Hawaiian fishery resources.
However, this does not mean to imply that potential impacts on fish are
negligible. Some species have particular characteristics which should be
carefully considered in determining the location of a Hawaiian disposal
site. For example, tunas, billfishes, and scads have pelagic eggs which may
be affected by manganese nodule processing wastes. Increased water
turbidity associated with the disposal of these wastes may also affect the
schooling behavior of small skipjack tuna.
In addition to direct effects on developing fishes, it is also
important to consider the impacts of the wastes on fish food resources. For
example, alteration of the plankton community may adversely affect fishes
with planktivorous pelagic larvae.
Demersal fish habitats are susceptible to the accumulation of waste
sediments. Species supporting fisheries inhabit waters ranging in depth
from a few meters (e.g., scads) to over 600 m (e.g., shrimps). Bottomfishes
are abundant in areas of high topographic relief, while pink and black
corals exist only on hard substrates free of sediment. Many of these
habitats are highly localized. Therefore, potential waste sites should be
thoroughly surveyed to document the presence or absence of productive
fisheries habitat.
In summary, given the current state of knowledge, it is difficult to
predict the magnitude of potential waste disposal impacts on Hawaiian
fishery resources. However, consideration of fisheries should not be
lessened as a result of this lack of information. It is important that the
disposal method and site be carefully chosen to avoid interfering with
fishing areas or the life cycles of economically valuable fish species.
423
------- |