DRAFT
Environmental Impact Statement
(EIS) for San Francisco Bay
Deep Water Dredged Material
Disposal Site Designation
December 1992
38°N
37°30'N
Transverse Mercator Projection
Scale
0 5 10 15 20
-123°30'W
-123°w
xvEPA
-122°30'w
U.S. Environmental Protection Agency
Region IX, 75 Hawthorne Street, San Francisco, CA 94105
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DRAFT
Environmental Impact Statement
(EIS) for San Francisco Bay
Deep Water Dredged Material
Disposal Site Designation
December 1992
Prepared by:
EPA Region DC
75 Hawthorne Street
San Francisco CA 94105
With the assistance of:
Science Applications International Corporation
10260 Campus Point Drive
San Diego, CA 92121-1578
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DRAFT
ENVIRONMENTAL IMPACT STATEMENT
FOR
SAN FRANCISCO BAY DEEP WATER
DREDGED MATERIAL DISPOSAL
SITE DESIGNATION
U.S. Environmental Protection Agency
Region IX
San Francisco, California
Comments on this administrative action should be addressed to:
Mr. Harry Seraydarian, Director
Water Management Division
U.S. Environmental Protection Agency
75 Hawthorne Street
San Francisco, California 94105
Comments must be received no later than:
January 25,1993, 45 days after publication of the notice of availability in the
Federal Register for the DEIS.
Copies of this EIS may be viewed at the following locations:
ABAG/MTC Library Alameda County Library
101 - 8th Street 3121 Diablo Avenue
Oakland, CA 94607 Hayward, CA 94545
Bancroft Library Berkeley Public Library
University of California 2090 Kittredge Street
Berkeley, CA 94720 Berkeley, CA 94704
Half Moon Bay Library Marin County Library, Civic Center
620 Correas Street 3501 Civic Center Drive
Half Moon Bay, CA 94019 San Rafael, CA 94903
Daly City Public Library Environmental Information Center
40 Wembley Drive San Jose State University
Daly City, CA 94015 125 South 7th Street
San Jose, CA 95112
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North Bay Cooperative Library Oakland Public Library
725 Third Street 125 - 14th Street
Santa Rosa, CA 95404 Oakland, CA 94612
Richmond Public Library San Francisco Public Library
325 Civic Center Plaza Civic Center, Larkin & McAllister
Richmond, CA 94804 San Francisco, CA 94102
San Francisco State University San Mateo County Library
1630 Hollo way Avenue 25 Tower Road
San Francisco, C A 94132 San Mateo, C A 94402
Santa Clara County Free Library Sausalito Public Library
1095 N. Seventh Street 420 Litho Street
San Jose, C A 95112 Sausalito, C A 94965
Stanford University Library
Stanford, CA 94305
Copies of the DEIS may be obtained from:
Marine Protection Section (W-7-1)
U.S. Environmental Protection Agency
75 Hawthorne Street
San Francisco, CA 94105
For further information contact:
Ms. Shelley Clarke
Marine Protection Section (W-7-1)
U.S. Environmental Protection Agency
75 Hawthorne Street
San Francisco, C A 94105
(415) 744-1162
Mr. Allan Ota
Marine Protection Section (W-7-1)
U.S. Environmental Protection Agency
75 Hawthorne Street
San Francisco, CA 94105
(415) 744-1164
11
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ABSTRACT
This environmental impact statement (EIS) evaluates the proposed designation of a deep-water
ocean dredged material disposal site as part of the Long-Term Management Strategy (LTMS) for
San Francisco Bay, California. The LTMS is a Federal and State partnership responsible for
addressing options for dredged material disposal, including ocean sites, sites within the Bay,
nonaquatic sites, and beneficial uses of dredged material. Once designated, the proposed ocean
site will provide a disposal option for an estimated 6 million yd3 per year of dredged material
over a 50-year period. Before ocean disposal may take place, proposed projects must
demonstrate a need for ocean disposal and material must be acceptable according to U.S.
Environmental Protection Agency and U.S. Army Corps of Engineers criteria and regulations.
The preferred alternative site (Alternative Site 5) is located on the continental rise off San
Francisco approximately 50 nmi from shore and in 2,500 to 3,000 m of water. Selection of the
preferred alternative site, as compared to two alternative ocean sites (Alternative Sites 3 and 4)
and the No-Action alternative, is based on evaluation of the 5 general and 11 specific criteria of
the Ocean Dumping Regulations listed at 40 CFR sections 228.5 and 228.6, respectively.
Alternative Site 5 was chosen as the preferred alternative site primarily because, in contrast to
the other alternative sites, it is located in deeper waters away from productive fishery areas and
in an area that has been used historically for disposal of low-level radioactive waste and chemical
and conventional munitions.
Use of the site is not expected to cause any significant long-term adverse environmental effects
outside of site boundaries. Within the site, sediment composition will be altered and benthic
infaunal and epifaunal communities will be affected due to burial and smothering by dredged
material. However, because this site is located in deep water, where organism abundances are
low, impacts are expected to be minimal. Potential impacts on water quality, plankton
communities, pelagic and demersal invertebrates and fishes, marine birds, marine mammals,
threatened and endangered species, and marine sanctuaries are expected to be insignificant.
Similarly, potential impacts to socioeconomic resources (such as commercial and recreational
fishing, military and commercial shipping, oil and gas or other mineral development, or cultural
and historical resources) are expected to be insignificant due to the distance offshore of the
preferred alternative site and minimal resource use in this area.
in
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IV
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DRAFT
ENVIRONMENTAL IMPACT STATEMENT
FOR
SAN FRANCISCO BAY DEEP WATER
DREDGED MATERIAL DISPOSAL
SITE DESIGNATION
Reviewed by:
U.S. Environmental Protection Agency
Region IX
Water Management Division
75 Hawthorne Street
San Francisco, CA 94105
(415)744-2125
Harry 6eraydarian
Director, Water Management Division
Approved and Submitted by:
U.S. Environmental Protection Agency
Region IX
Office of the Regional Administrator
75 Hawthorne Street
San Francisco, C A 94105
(415) 744-1001
Daniel W. McGovern
Regional Administrator
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VI
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TABLE OF CONTENTS
Cover Sheet i
Abstract iii
Agency Concurrence Sheet v
Table of Contents vii
List of Figures xv
List of Tables xxi
Glossary of Acronyms xxv
Unit Conversion Table xxix
EXECUTIVE SUMMARY S-l
S.I Introduction S-l
S.2 Affected Environment S-3
S.2.1 Physical Environment S-4
S.2.2 Biological Environment S-5
S.2.3 Socioeconomic Environment S-6
S.3 Environmental Consequences S-6
S.3.1 Physical Environment S-7
S.3.2 Biological Environment S-7
S.3.3 Socioeconomic Environment S-8
S.4 Comparison of the Alternative Ocean Disposal Sites With the 5
General and 11 Specific Site Selection Criteria S-9
S.4.1 General Selection Criteria S-9
S.4.2 Specific Site Selection Criteria S-ll
S.5 Conclusions S-15
CHAPTER 1
INTRODUCTION 1-1
1.1 General Introduction 1-1
1.2 Purpose of and Need for Action 1-2
1.3 Proposed Action 1-9
1.4 Areas of Controversy 1-12
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1.5 Issues To Be Resolved 1-13
1.6 Regulatory Framework 1-13
1.6.1 International Treaty 1-13
1.6.2 Federal Laws and Regulations 1-13
1.6.2.1 Marine Protection, Research and Sanctuaries Act
of 1972, as amended (33 USC Section 1401 et
sea.) 1-13
1.6.2.2 National Environmental Policy Act of 1969 (42
USC Section 4341 et sea.) 1-14
1.6.2.3 Clean Water Act of 1972 (33 USC Section 1251
et sea.) 1-15
1.6.2.4 Clean Air Act as Amended (42 USC Section
1451 etsea.) 1-15
1.6.2.5 Fish and Wildlife Coordination Act of 1958 (16
USC Section 661 et sea.) 1-16
1.6.2.6 Coastal Zone Management Act of 1972 (16 USC
Section 1456 et sea.) 1-16
1.6.2.7 Endangered Species Act of 1973 (16 USC
Section 1531 et sea.) 1-17
1.6.2.8 National Historic Preservation Act of 1966 (16
USC Parts 470 et sea.) 1-17
1.6.3 Executive Orders 1-17
1.6.3.1 Executive Order 11593, Protection and
Enhancement of the Cultural Environment (36 FR
8921. May 15. 1971) 1-17
1.6.3.2 Executive Order 12372, Intergovernmental
Review of Major Federal Programs (47 FR 3059,
July 16. 1982) 1-18
1.6.4 State of California 1-18
1.6.4.1 California Coastal Act of 1976, Public Resources
Code Section 3000 et sea. 1-18
1.6.4.2 California Environmental Quality Act, June 1986
Public Resources Code Parts 21000-21177 1-18
1.7 Relationship to Previous NEPA Actions or Other Facilities That May
Be Affected by Designation of the Disposal Site 1-19
CHAPTER 2
ALTERNATIVES INCLUDING THE PROPOSED ACTION 2-1
2.1 Description of Alternatives 2-1
2.1.1 No-Action Alternative 2-2
2.1.2 Ocean Disposal Alternatives 2-3
2.1.2.1 Historically Used ODMDSs 2-10
2.1.2.2 Sensitive Areas 2-11
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2.1.2.3 Incompatible Use Areas 2-17
2.1.3 San Francisco Bay and Nonaquatic Disposal and Reuse
Alternatives 2-18
2.1.3.1 San Francisco Bay Alternatives 2-18
2.1.3.2 Nonaquatic Disposal and Reuse Alternatives 2-22
2.2 Discussion of Alternatives 2-26
2.2.1 Alternatives Not Considered for Further Analysis 2-27
2.2.2 Compliance of the Alternative Sites and Study Area 2
with General Criteria for the Selection of Sites 2-28
2.2.2.1 General Criterion 40 CFR 228.5(a) 2-28
2.2.2.2 General Criterion 40 CFR 228.5(b) 2-29
2.2.2.3 General Criterion 40 CFR 228.5(c) 2-30
2.2.2.4 General Criterion 40 CFR 228.5(d) 2-30
2.2.2.5 General Criterion 40 CFR 228.5(e) 2-31
2.2.3 Comparison of the Alternatives to EPA's 11 Specific
Criteria for Site Selection 40 CFR 228.6(a) 2-32
2.2.4 Selection of the Preferred Alternative 2-32
CHAPTER 3
AFFECTED ENVIRONMENT 3-1
3.1 Ocean Disposal Site Characteristics 3-1
3.1.1 Historical Use of the Study Region (40 CFR 228.5[e]) 3-1
3.1.1.1 Dredged Material Disposal 3-1
3.1.1.2 Other Waste Disposal 3-6
3.1.1.3 Acid Waste 3-8
3.1.1.4 Cannery Wastes 3-8
3.1.1.5 Radioactive Waste 3-8
3.1.1.6 Chemical and Conventional Munitions Waste .... 3-11
3.1.1.7 Refinery Waste 3-13
3.1.1.8 Vessel and Dry Dock Sections 3-14
3.1.1.9 Summary of Historical Disposal in Relation to
the LTMS Study Areas 3-16
3.1.2 Types and Quantities of Wastes Proposed To Be
Disposed of (40 CFR 228.6[a][4]) 3-16
3.1.3 Existence and Effects of Current and Previous Discharge
and Dumping in the Area (40 CFR 228.6[a][7]) 3-17
3.1.4 Feasibility of Surveillance and Monitoring (40 CFR
228.5[d] and 228.6[a][5]) 3-19
3.1.4.1 Surveillance 3-19
3.1.4.2 Monitoring 3-19
3.2 Physical Environment 3-20
3.2.1 Meteorology and Air Quality 3-20
3.2.2 Physical Oceanography 40 CFR 228.6(a)(6) 3-28
IX
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3.2.2.1 Regional Current Patterns 3-28
3.2.2.2 Study Region-Specific Currents 3-31
3.2.2.3 Outer Shelf (Study Area 2) Currents 3-33
3.2.2.4 Slope (Study Areas 3 through 5) Currents 3-36
3.2.2.5 Near-Surface Currents Over the Slope 3-36
3.2.2.6 Mid-Depth Currents Over the Slope 3-37
3.2.2.7 Deep Currents Over the Slope 3-39
3.2.2.8 Near-bed Currents Over the Slope 3-39
3.2.2.9 Summary of Observed Currents 3-41
3.2.3 Water Column Characteristics 40 CFR 228.6(a)(9) 3-42
3.2.3.1 Temperature-Salinity Properties 3-43
3.2.3.2 Hydrogen Ion Concentration (pH) 3-44
3.2.3.3 Turbidity 3-44
3.2.3.4 Dissolved Oxygen 3-50
3.2.3.5 Nutrients 3-52
3.2.3.6 Trace Metals 3-53
3.2.3.7 Hydrocarbons 3-57
3.2.4 Regional Geology 3-58
3.2.4.1 Topography 3-58
3.2.4.2 Sediment Transport 3-60
3.2.5 Sediment Characteristics 3-66
3.2.5.1 Grain Size 3-66
3.2.5.2 Mineralogy 3-73
3.2.5.3 Sediment Organic Content 3-74
3.2.5.4 Sediment Trace Metals 3-74
3.2.5.5 Sediment Hydrocarbons 3-84
3.2.5.6 Sediment Radionuclides 3-93
3.3 Biological Environment 3-94
3.3.1 Plankton Community 3-94
3.3.1.1 Phvtoplankton 3-95
3.3.1.2 Zooplankton 3-97
3.3.2 Invertebrates 3-104
3.3.2.1 Benthic Infauna 3-104
3.3.2.2 Demersal Epifauna 3-122
3.3.2.3 Pelagic Invertebrates 3-139
3.3.2.4 Commercially Important Species 3-141
3.3.3 Fish Community 3-142
3.3.3.1 Demersal Species 3-142
3.3.3.2 Pelagic Species 3-159
3.3.3.3 Commercially and Recreationally Important
Species 3-161
3.3.4 Marine Birds 3-166
3.3.4.1 Distribution. Abundance, and Ecology of
Representative Breeding Species 3-179
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3.3.4.2 Summary of Study Area Usage by Marine Bird
Species 3-185
3.3.5 Marine Mammals 3-187
3.3.5.1 Cetaceans 3-191
3.3.5.2 Pinnipeds 3-211
3.3.5.3 Fissipeds 3-223
3.3.6 Threatened, Endangered, and Special Status Species 3-225
3.3.6.1 Species Observed Regularly Within the Study
Region 3-225
3.3.6.2 Species Occurring Irregularly Within the Study
Region 3-230
3.3.7 Marine Sanctuaries and Special Biological Resource
Areas 3-233
3.3.7.1 Federally Protected Areas 3-233
3.3.7.2 State Protected Areas 3-239
3.3.8 Potential for Development or Recruitment of Nuisance
Species 3-240
3.4 Socioeconomic Environment 3-241
3.4.1 Commercial and Recreational Fisheries 3-241
3.4.1.1 Existing Fisheries 3-241
3.4.1.2 Potential Fisheries 3-255
3.4.2 Mariculture 3-256
3.4.3 Shipping 3-257
3.4.4 Military Usage 3-261
3.4.5 Mineral Or Energy Development 3-263
3.4.6 Recreational Activities 3-263
3.4.7 Cultural and Historical Areas 3-264
CHAPTER 4
ENVIRONMENTAL CONSEQUENCES 4-1
4.1 Introduction 4-1
4.2 Preferred Alternative 4-2
4.2.1 Effects on the Physical Environment 4-7
4.2.1.1 Air Quality 4-8
4.2.1.2 Physical Oceanography 4-9
4.2.1.3 Water Quality 4-12
4.2.1.4 Geology and Sediment Characteristics 4-35
4.2.2 Effects on Biological Environment 4-47
4.2.2.1 Plankton 4-47
4.2.2.2 Infauna 4-48
4.2.2.3 Epifauna 4-55
4.2.2.4 Fishes 4-57
4.2.2.5 Marine Birds 4-58
XI
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4.2.2.6 Marine Mammals 4-60
4.2.2.7 Threatened, Endangered, and Special Status
Species 4-62
4.2.2.8 Marine Sanctuaries 4-63
4.2.3 Effects on Socioeconomic Environment 4-64
4.2.3.1 Commercial and Recreational Fishing 4-64
4.2.3.2 Commercial Shipping 4-65
4.2.3.3 Mineral or Energy Development 4-65
4.2.3.4 Military Usage 4-66
4.2.3.5 Recreational Activities 4-66
4.2.3.6 Cultural and Historical Resources 4-67
4.2.3.7 Public Health and Welfare -. . . . 4-67
4.3 No-Action Alternative 4-67
4.4 Other Ocean Disposal Alternatives 4-69
4.4.1 Effects on the Physical Environment 4-69
4.4.1.1 Air Quality 4-69
4.4.1.2 Physical Oceanography 4-69
4.4.1.3 Water Quality 4-70
4.4.1.4 Geology and Sediment Characteristics 4-72
4.4.2 Effects on Biological Environment 4-74
4.4.2.1 Plankton 4-74
4.4.2.2 Infauna 4-75
4.4.2.3 Epifauna 4-76
4.4.2.4 Fishes 4-77
4.4.2.5 Marine Birds 4-78
4.4.2.6 Marine Mammals 4-79
4.4.2.7 Threatened, Endangered, and Special Status
Species 4-80
4.4.2.8 Marine Sanctuaries 4-81
4.4.3 Effects on Socioeconomic Environment 4-82
4.4.3.1 Commercial and Recreational Fishing 4-82
4.4.3.2 Commercial Shipping 4-83
4.4.3.3 Mineral or Energy Development 4-83
4.4.3.4 Military Usage 4-84
4.4.3.5 Recreational Activities 4-85
4.4.3.6 Cultural and Historical Resources 4-85
4.4.3.7 Public Health and Welfare 4-86
4.5 Other Alternatives 4-87
4.6 Management of the Disposal Site 4-87
4.6.1 Ocean Dumping Permits 4-87
4.6.2 Site Management and Monitoring 4-90
4.7 Cumulative Impacts as a Result of the Project 4-92
4.7.1 Radioactive Waste Disposal Sites 4-93
4.7.2 Munitions Waste Sites 4-94
XII
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4.7.3 Navy Section 103 Dredged Material Disposal 4-94
4.7.4 BIB Dredged Material Disposal Site 4-95
4.8 Relationship Between Short-Term Use and Long-Term Resource
Uses 4-95
4.9 Irreversible or Irretrievable Commitment of Resources 4-96
CHAPTER 5
COORDINATION 5-1
5.1 Notice of Intent and Public Scoping Meeting 5-1
5.2 San Francisco Bay Long-Term Management Strategy for Dredged
Material 5-3
5.3 LTMS Ocean Studies Work Group 5-5
5.4 Formal Consultation 5-15
5.5 Public Distribution of the Draft Environmental Impact Statement .... 5-15
CHAPTER 6
PREPARERS AND CONTRIBUTORS 6-1
CHAPTER 7
BIBLIOGRAPHIC REFERENCES 7-1
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xiv
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LIST OF FIGURES
FIGURE TITLE PAGE
S.I. Locations of Study Areas and Alternative Sites in the LTMS Study
Region S-2
1.1.1. Evaluation Process for Dredged Material Permits 1-5
1.3-1. Locations of Study Areas 1 Through 5 and Alternative Sites 3, 4,
and 5 in the LTMS Study Regions 1-11
1.7-1. Locations of Existing ODMDSs, Ocean Outfalls, National Marine
Sanctuaries, Submarine Operating Areas, Vessel Traffic Lanes, and
Historical Waste Disposal Sites in the LTMS Study Region 1-20
2.1-1. Locations of National Marine Sanctuaries, Areas of Special
Biological Significance, Reserves, and Features of Potential
Scientific Importance in the LTMS Study Region 2-5
2.1-2. Location of Physiographic Features in the LTMS Study Region 2-7
2.1-3. Location of Navigation Channels and Precautionary Zones in the
LTMS Study Region 2-8
2.1-4. Location of Submarine Operating Areas in the LTMS Study Region 2-9
2.1-5. Location of the Ocean Disposal Sites Evaluated by the COE in the
Vicinity of the Gulf of the Farallones 2-14
2.1-6. Locations of Study Areas 2 Through 5 Within the LTMS Study
Region as Related to Sensitive and Incompatible Use Areas 2-19
3.1-1. Locations of Previously Used Ocean Waste Disposal Sites Within
the LTMS Study Region 3-3
3.2-1. Surface Wind Vectors at Four NDBC Buoys in the Vicinity of the
Gulf of the Farallones During 1991 3-24
3.2-2. Locations of Current Meter Stations A Through F 3-34
3.2-3. Subtidal Currents at Station A 3-35
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3.2-4. Schematic Representation of the Three-Dimensional Structure of the
"Wedge-Shaped" Region of Coherent Mid-Depth Flow Over the
Slope 3-38
3.2-5. Subtidal Currents at Station E 3-40
3.2-6. Satellite Images of Sea Surface Temperatures Within the LTMS
Study Region During (A) February and (B) May 1991 3-45
3.2-7. A Composite Profile of Dissolved Oxygen Concentration in the
Water Column Over the Continental Slope off San Francisco and the
Gulf of the Farallones 3-51
3.2-8. Vertical Profiles of Silicate, Phosphate, and Nitrate Concentrations
at CalCOFI Station 60060 (37°36.8'N, 123°36.5'W) in July 1984 3-54
3.2-9. Mapped Distribution of Ripples and Scour Lag Deposits (High
Kinetic Energy Bottoms) and Sediments Dominated by Biogenic
Features (Low Kinetic Energy Bottoms) 3-61
3.2-10. Mapped Distribution of Major Modal Grain Size (phi units) 3-62
3.2-11. Low Kinetic Energy Zones in LTMS Study Area 5 3-65
3.2-12. Patterns in Sediment Grain Size (mean phi) with Depth Within the
LTMS Study Region 3-67
3.2-13. Patterns in Sediment Silt Content with Depth Within the LTMS
Study Region 3-71
3.2-14. Patterns in Sediment Total Organic Carbon Concentrations with
Depth Within the LTMS Study Region 3-75
3.2-15. Sediment Concentrations of: (A) Aluminum; (B) Cadmium; (C)
Chromium, and (D) Copper Within the LTMS Study Region 3-80
3.2-16. Sediment Concentrations of: (A) Total n-alkanes and (B) Total
PAHs Within the LTMS Study Region 3-86
3.2-17. Sediment Concentrations of: (A) Total n-alkanes and Organic
Carbon and (B) Total PAH and Organic Carbon Within the LTMS
Study Region 3-88
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3.2-18. Sediment Concentrations of Total DDT and Total PCBs Within the
LTMS Study Regions 3-89
3.3.1-1. Abundance of Total Fish Larvae Versus Bottom Depth (top panel)
and by Season (bottom panel) 3-102
3.3.2-1. Bar Graph of the Total Number of Species at Each Station in LTMS
Study Areas 3, 4, and Pioneer Canyon, Arranged by Depth 3-110
3.3.2-2. Species Accumulation Curve for 68 Samples Collected in Study
Areas 3, 4, and 5 in 1990 and 1991 3-119
3.3.2-3. Infaunal Densities at Two Transects on the U.S. Atlantic Continental
Slope and Rise and One Transect off the Farallon Islands 3-121
3.3.2-4 Number of Benthic Megafaunal Species by General Taxonomic
Group Collected During Trawl Surveys by SAIC (1992b) at Each
Transect; Transects Sorted in Order of Increasing Depth 3-124
3.3.2-5 Sum of Densities of Megafaunal Invertebrate Species by General
Taxonomic Group Collected During Trawl Surveys by SAIC
(1992b) at Each Transect; Transects Sorted in Order of Increasing
Depth 3-131
3.3.2-6 Sum of Biomasses of Benthic Megafaunal Invertebrate Species by
General Taxonomic Group Collected During Trawl Surveys by
SAIC (1992b) at Each Transect; Transects Sorted in Order of
Increasing Depth 3-132
3.3.3-1. Community Assemblages on Continental Shelf and Slope off San
Francisco, California, for Common Fishes Collected in Trawls by
SAIC (1992b), Cailliet et al. (1992), and NMFS (1992) in LTMS
Study Areas 2, 3, 4, and 5 3-149
3.3.3-2. Summary of Distribution Patterns of Benthic Communities (Fishes
and Megafaunal Invertebrates) from Trawl and ROV Studies
Conducted in September and October 1991 3-151
3.3.3-3. Number of Benthic Fish Species by General Taxonomic Group
Collected During Trawl Surveys by SAIC (1992b) by Each
Transect; Transects Sorted in Order of Increasing Depth 3-153
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3.3.3-4. Sum of Densities of Benthic Fish Species by General Taxonomic
Group Collected During Trawl Surveys by SAIC (1992b) at Each
Transect; Transects Sorted in Order of Increasing Depth 3-154
3.3.3-5. Sum of Biomasses of Benthic Fish Species by General Taxonomic
Group Collected During Trawl Surveys by SAIC (1992b) at Each
Transect; Transects Sorted in Order of Increasing Depth 3-155
3.3.4-1. Density Estimates for all Marine Bird Species During June 1986, a
Poor Rockfish Year 3-175
3.3.4-2. Density Estimates for all Marine Bird Species during June 1987, a
good Rockfish Year 3-176
3.3.4-3. Density Estimates for all Marine Bird Species during June 1991, an
Intermediate Rockfish year 3-177
3.3.4-4. Tufted Puffin Counts in the Gulf of the Farallones Region
1985-1991 3-184
3.3.4-5. California Brown Pelican Counts in the Gulf of the Farallones
Region, 1985-1991 3-186
3.3.5-1. Whale Migrations (Northern and Southern) and Times During
Which Each Species May Occur in the Study Region 3-194
3.3.5-2. Pacific White-Sided Dolphin Counts in the Gulf of the Farallones
Region, 1985-1991 3-195
3.3.5-3. Northern Right Whale Dolphin Counts in the Gulf of the Farallones
Region, 1985-1991 3-197
3.3.5-4. Risso's Dolphin Counts in the Gulf of the Farallones Region,
1985-1991 3-198
3.3.5-5. Dall's Porpoise Counts in the Gulf of the Farallones Region,
1985-1991 3-200
3.3.5-6. Harbor Porpoise Counts in the Gulf of the Farallones Region,
1985-1991 3-201
3.3.5-7. Gray Whale Counts in the Gulf of the Farallones Region,
1985-1991 3-203
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3.3.5-8a. Humpback Whale Counts in the Gulf of the Farrallones Region,
August 1990 and 1991 3-205
3.3.5-8b. Humpback Whale Counts in the Gulf of the Farallones Region,
1985-1991 3-206
3.3.5-9. Blue Whale Counts in the Gulf of the Farallones Region, August
1990 and 1991 3-208
3.3.5-10. Minke Whale Counts in the Gulf of the Farallones Region,
1985-1991 3-209
3.3.5-1 la. California Sea Lion Counts in the Gulf of the Farallones Region,
August 1990 and 1991 3-214
3.3.5-1 Ib. Blue Whale Counts in the Gulf of the Farallones Region,
1985-1991 3-215
3.3.5-12. Northern Elephant Seal Counts in the Gulf of the Farallones Region,
1985-1991 3-217
3.3.5-13a. Northern Sea Lion Counts in the Gulf of the Farallones Region,
August 1990 and 1991 3-219
3.3.5-13b. Northern Sea Lion Counts in the Gulf of the Farallones Region,
1985-1991 3-220
3.3.5-14a. Northern Fur Seal Counts in the Gulf of the Farallones Region,
August 1990, February, May, August, November 1991 3-221
3.3.5-14b. Northern Fur Seal Counts in the Gulf of the Farallones Region,
1985-1991 3-222
3.3.5-15. Harbor Seal Counts in the Gulf of the Farallones Region,
1985-1991 3-224
3.3.7-1. National Marine Sanctuaries in the LTMS Study Region 3-234
3.3.7-2. Farallon National Wildlife Refuge, Farallon Islands Area of Special
Biological Significance, and Farallon Islands Game Refuge 3-235
3.4-1. CDFG Commercial Fisheries Catch Blocks Showing Locations of
Blocks and Total Catches of Fishes and Invertebrates From 1978 to
xix
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1986 Within the LTMS Study Areas. Total Catches are Given in
Millions of Pounds (MP) 3-243
3.4-2. Commercially Collected Megafaunal Invertebrates (By Catch Block
in Pounds) Within the LTMS Study Areas between 1970 and 1986 3-244
3.4-3. Commercially Collected Fishes (By Catch Block in Pounds) Within
the LTMS Study Areas between 1970 and 1986 3-245
4.2-1. Schematic of a Particle Cloud Sinking Through the Water Column 4-18
4.2-2. Model-Predicted Visitation Frequencies (red) and Average Particle
Concentrations (green) for Clay-Silt (Class 6) Sediments Discharged at the
Preferred Alternative Site 4-23
4.2-3. Model-Predicted Visitation Frequencies (red) and Average Particle
Concentrations (green) for Clay-Silt (Class 6) Sediments Discharged at the
Alternative Site 3 4-25
4.2-4. Model-Predicted Visitation Frequencies (red) and Average Particle
Concentrations (green) for Clay-Silt (Class 6) Sediments Discharged
at the Alternative Site 4 4-27
4.2-5. Model-Predicted Visitation Frequencies (red) and Average Particle
Concentrations (green) for Clay-Silt (Class 6) Sediments Discharged
at the Preferred Alternative Site Using a Diffusion Coefficient of
D=10m2/sec 4-29
4.2-6. Model-Predicted Bottom Deposit Thicknesses (in mm) From
Discharges of Six Million yd3 of Clay-Silt Type Material Over a
One-Year Period at the Preferred Alternative Site (red), Alternative
Site 3 (green), and Alternative Site 4 (blue) 4-41
4.2-7. Model-Predicted Bottom Deposit Thicknesses (in mm) From
Discharges of Six Million yd3 of Mostly Sand Type Material Over a
One-Year Period at the Preferred Alternative Site (red), Alternative
Site 3 (green), and Alternative Site 4 (blue) 4-43
5.2-1. Long Term Management Strategy (LTMS) Management and
Implementation Structure 5-4
xx
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LIST OF TABLES
TABLE TITLE PAGE
1.1-1. Five General and Eleven Specific Site Selection Criteria 1-3
1.2-1. Projected Annual and 50-Year Dredging Volumes for Projects in
San Francisco Bay 1-8
2.1-1. Areas of Special Biological Significance (ASBSs), Reserves,
National Marine Sanctuaries (NMS), and Features of Potential
Scientific Significance Shown in Figure 2.1-1 2-6
2.1-2. Potential Ocean Disposal Sites Evaluated by the COE, as Shown in
Figure 2.1-5 2-15
2.1-3. Designated Open Water Dredged Material Disposal Sites in the San
Francisco Bay Region 2-20
2.1-4. Upland Reuse/Disposal Options Classified as "Highly Feasible" by
the LTMS Nonaquatic/Reuse Work Group 2-24
2.2-1. Comparison of the Three Alternative Ocean Disposal Sites and
Study Area 2 Based on the 11 Specific Criteria at 40 CFR 228.6(a) 2-33
3.1-1. Summary of Dredged Material Disposal Site Locations and Disposal
Activities Within the LTMS Study Region 3-4
3.1-2. Summary of Waste Disposal in the LTMS Study Region 3-7
3.1-3. Radioactive Waste Disposal Sites in the Gulf of the Farallones 3-10
3.1-4. Summary of Munitions Discharges in the LTMS Study Region 3-12
3.1-5. Summary of Vessel and Dry Dock Disposal in the Vicinity of the
Gulf of the Farallones 3-15
3.2-1. Meteorological Conditions for the Coastal Area off San Francisco 3-22
3.2-2. A. Annual Air Pollutant Summary for Central San Francisco Bay
Stations During 1988-1991; and B. California and National
Standards for Individual Pollutants 3-25
xxi
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3.2-3. Wave Observations (Percent Occurrence) Based on U.S. Army Corp
of Engineers (COE) Wave Data at Station 20 (Dates Unspecified),
Located Approximately 7 nm southwest of the Golden Gate Bridge,
San Francisco, California 3-32
3.2-4. Trace Metal Concentrations in Seawater in the Vicinity of the Gulf
of the Farallones '3-55
3.2-5. Descriptive Statistics for Sediment Parameters from Study Areas 2,
3, 4, and 5 3-68
3.2-6. Trace Metal Concentrations in Sediments for Study Areas 2, 3, 4,
and 5, and Pioneer Canyon 3-76
3.2-7. Trace Metals in Sediments from the Study Areas and Comparison
Data 3-78
3.2-8. Hydrocarbon Concentrations in Sediments for Study Areas 2, 3,
and 4, and Pioneer Canyon 3-85
3.2-9. Hydrocarbons in Sediments from the Study Areas and Comparison
Data 3-92
3.3.1-1. Dominant Zooplankton in Waters Offshore Central California Based
on a Review of CalCOFI Atlases, Hatfield (1983) and Tasto et al.
(1981; 1975-1977 samples) 3-98
3.3.2-1. Total Number of Species Belonging to Each Major Taxonomic
Group Collected from Study Areas 2, 3, 4, and 5 (SAIC 1992c,d) 3-105
3.3.2-2. Benthic Infaunal Community Parameters for Study Areas 2, 3, 4,
and 5 (SAIC 1992a,c) 3-107
3.3.2-3A. Rank Order of Density for Demersal Megafaunal Invertebrates
Collected During Trawl Surveys by SAIC (1992b) in Study Areas 2
through 4 and Adjacent Sites in Pioneer Canyon (PC) and in "Mid-
Depth" (MD) 3-125
3.3.2-3B. Rank Order of Biomass for Demersal Megafauna Collected During
Trawl Surveys of Study Areas 2 Through 4 and Adjacent Sites in
Pioneer Canyon (PC) and in "Mid-Depth" (MD) (SAIC 1992b) 3-128
xxn
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3.3.3-1 A. Rank Order of Density (number of individuals/hectare) by
Increasing Trawl Depth for Demersal Fishes Collected by SAIC
(1992b) During Surveys in Study Areas 2 Through 4 and Adjacent
Sites in Pioneer Canyon (PC) and at "Mid-Depth" (MD) 3-143
3.3.3-IB. Rank Order of Biomass by Increasing Trawl Depth for Demersal
Fishes Collected by SAIC (1992b) During Surveys in Study Areas 2
Through 4 and Adjacent Sites in Pioneer Canyon (PC) and at "Mid-
Depth" (MD) 3-145
3.3.3-2. Summary by Study Area of Demersal Fish Community
Characteristics 3-147
3.3.3-3. Summary of Common Commercially and Recreationally Important
Fishes Within the LTMS Study Areas 3-163
3.3.4-1. Species and General Characteristics of Marine Birds Observed Off
California in the Vicinity of the Gulf of the Farallones 3-168
3.3.4-2. Relative Densities of the Ten Key Marine Bird Species Within the
Four LTMS Study Areas 3-174
3.3.5-1. Marine Mammals Observed in the Vicinity of the Gulf of the
Farallones 3-189
3.3.5-2. Relative Densities of Marine Mammal Species Within the Four
LTMS Study Areas 3-212
3.3.6-1. Threatened or Endangered Species Occurring in the Study Areas
(modified from KLI 1991) 3-226
3.4-1. Total Vessel Transits in the San Francisco Bay Region, 1980-1991 3-258
3.4-2. Percentage by Category of Total Vessel Movements That Include
Transiting Through the Golden Gate 3-260
3.4-3. Incidents Involving Tugs, Barges, and Self Propelled Dredges
Within and Near San Francisco Bay, 1980-1989 3-262
4.1-1. Summary of Potential Environmental Impacts at the Preferred
Alternative and Alternative Sites 3 and 4 4-3
xxin
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4.2-1. Model-Predicted Maximum Concentrations of Air Pollutants in
Central San Francisco Bay and the Corresponding Air Quality
Standards 4-10
4.2-2. Particle Size Classes and Sinking Velocities Used in the Sediment
Deposition Model 4-16
4.2-3. Model-Predicted Disposal Plume Visitation Frequencies, Mean
Depth, and Exposure Times for Simulated Discharges at the
Preferred Alternative (Alternative Site 5) and Alternative Sites 3
and 4 4-21
4.2-4. Model-Predicted Deposit Thicknesses, Areal Coverage, and Material
Losses Due to Transport Outside of the Model Boundaries 4-39
5.2-1. Members of the LTMS Technical Review Panel 5-6
5.2-2. Members of the LTMS Policy Review Committee 5-7
5.3-1. LTMS Ocean Studies Work Group (OSWG) Members 5-9
5.3-2. Agencies and Organizations that Provided Written Comments on
LTMS Ocean Studies Plan, February 1990 to June 1991 5-11
5.3-3. Attendance at LTMS Ocean Studies Work Group Meetings,
February 1990 to September 1992 5-12
5.5-1. Distribution List for Draft Environmental Impact Statement (DEIS) 5-21
5.5-2. Locations Where the DEIS Can Be Reviewed or Requested 5-29
6-1. List of EIS Preparers 6-2
6-2. List of EIS Contributors 6-5
xxiv
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GLOSSARY OF ACRONYMS
ACSAR
ADCP
AEC
ASBS
BART
BCDC
BFBA
CalCOFI
CBNMS
CCC
CDFG
CEQ
CEQA
CFR
CHASE
CMDA
CO
CODE
COE
CSWRCB
CWA
CZMA
CZMPs
DDD
DDE
DDT
Atlantic Continental Slope and Rise Program (U.S.)
acoustic doppler current profiler
Atomic Energy Commission
Area of Special Biological Significance
Bay Area Rapid Transit
Bay Conservation and Development Commission
Bay Farm Borrow Area
California Cooperative Oceanic Fisheries Investigations
Cordell Bank National Marine Sanctuary
California Coastal Commission
California Department of Fish and Game
Council on Environmental Quality
California Environmental Quality Act
Code of Federal Regulations
Cut Holes and Sink 'Em
chemical munitions dumping area
carbon monoxide
Coastal Ocean Dynamics Experiment
Corps of Engineers (U.S. Army)
California State Water Resources Control Board
Clean Water Act
Coastal Zone Management Act
California Coastal Zone Management Plans
dichlorodiphenyldichloroethane
dichlorodiphenyldichloroethylene
dichlorodiphenyltrichloroethane
xxv
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DEIS
Eh
EIR
EIS
ENSO
EPA
ESA
FEIS
FR
FWS
GOFNMS
INPFC
km
LDC
LSMs
LTMS
MB
MBNMS
MD
MMPA
MMS
MPRSA
NDBC
NEPA
NESS
NMFS
nmi
NMS
NO2
NOAA
draft EIS
redox potential
Environmental Impact Report
Environmental Impact Statement
El Nino/Southern Oscillation
Environmental Protection Agency (U.S.)
Endangered Species Act (Federal)
final EIS
Federal Register
Fish and Wildlife Service (U.S.)
Gulf of the Farallones National Marine Sanctuary
International North Pacific Fisheries Commission
kilometers
London Dumping Convention
least-squares means
Long-Term Management Strategy
Monterey Bay
Monterey Bay National Marine Sanctuary
mid-depth
Marine Mammal Protection Act
Minerals Management Service
Marine Protection, Research and Sanctuaries Act
National Data Buoy Center
National Environmental Policy Act
Normalized Expected Species Shared
National Marine Fisheries Service
nautical mile
National Marine Sanctuaries
nitrogen dioxide
National Oceanic and Atmospheric Administration
xxvi
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NODS
NOX
NS&T
OAQPS TTN
OCS
ODMDS
ODSS
OMZ
OSC
PAH
PC
PCBs
PDEIS
PM
ppb
ppm
ppt
PRBO
ROV
RPD
RWQCB
SFBRWQCB
SHPO
SO2
SWOOP
T-S
TSS
USCG
USFWS
Navy Ocean Disposal Site
oxides of nitrogen
National Status & Trends
Office of Air Quality, Planning and Standards Technology Transfer
Network Bulletin Board System
Outer Continental Shelf
ocean dredged material disposal site
Ocean Dumping Surveillance System
oxygen minimum zone
Oakland Scavenger Company
polynuclear aromatic hydrocarbon
Pioneer Canyon
polychlorinated biphenyls
preliminary draft EIS
paniculate matter
parts-per-billion
parts-per-million
parts-per-thousand
Point Reyes Bird Observatory
remotely operated vehicle
redox potential discontinuity
Regional Water Quality Control Board
San Francisco Bay Regional Water Quality Control Board
State Historic Preservation Officer
sulfur dioxide
Southwest Ocean Outfall Project
temperature-salinity
total suspended solids
United States Coast Guard
United States Fish and Wildlife Service
xxvu
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USGS United States Geological Survey
USN United States Navy
USSC United States Steel Corporation
VOC volatile organic compounds
VTS Vessel Traffic Service (San Fransisco)
yd3 cubic yards
ZSF zone of siting feasibility
(a micro
xxvni
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Unit Conversion Table (Metric System with U.S. Equivalents)
x
X
Metric Unit \
U.S. Equivalents)
Length/Depth .
millimeter (mm)
centimeter (cm)
X
meter (m)
kilometer (km)
0.039 inches (in)
0.39 inches (in)
39.37 inches (in)
3.28 feet (ft)
0.55 fathoms (fm)
0.62 statute miles (mi)
0.53 nautical miles (nmi)
Area
square centimeter (cm2)
square meter (m2)
square kilometer (km2)
hectare (ha) = 10,000 m2
0.155 square inches (in2)
1.1 96 square yards (yd2)
0.3861 square statute miles (mi2)
0.292 square nautical miles (nmi2)
2.471 acres
Volttroe
cubic centimeter (cm3)
milliliter (ml)
cubic meter (m3)
liter (I)
0.061 cubic inches (in3)
i
1.31 cubic yards (yd3)
61 .02 cubic inches (in3)
Metric Unit
U.S, Equivalents)
Mass
gram (g)
1,000 milligram (mg)
kilogram (kg)
metric ton (MT)
0.035 ounces (oz)
2.2046 pounds (Ib)
1.1 tons
2,205 pounds (Ib)
Speed
centimeter per second (cm/sec)
meter per second (m/sec)
kilometer per hour (km/h)
0.02 knots (kn)*
1.94 knots (kn)
2.24 statute miles per hour (mi/hr)
0.55 knots (kn)
Tempwatws
degree Celsius (°C)
0°C
100°C
degree Fahrenheit (°F)
= (1.8x°C) + 32
32°F (freezing point of water)
212°F (boiling point of water)
*1 knot (1 nautical mile per hour) equals 1.15 statute (land) miles per hour.
AK0009.W51
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xxx
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EXECUTIVE SUMMARY
S.I Introduction
This Draft Environmental Impact Statement (DEIS) evaluates the proposed designation of a deep
water ocean dredged material disposal site (ODMDS) off San Francisco, California (Figure S-l).
The U.S. Environmental Protection Agency (EPA), Region DC, is issuing this EIS in accordance
with Title I of the Marine Protection, Research, and Sanctuaries Act (MPRSA) and as required
by EPA's national policy on the designation of ocean disposal sites (39 FR 37119, October 21,
1974).
The EIS has been prepared in coordination with other components of the Long-Term
Management Strategy (LTMS) for San Francisco Bay, an effort led by a Federal and State
partnership consisting of EPA, U.S. Army Corps of Engineers (COE), the San Francisco Bay
Regional Water Quality Control Board (SFBRWQCB), and the San Francisco Bay Conservation
and Development Commission (BCDC). An LTMS goal is to provide "timely, technically
feasible, cost-effective, and environmentally acceptable disposal alternatives for dredged
material." Disposal options, including sites within the Bay, nonaquatic sites, and ocean disposal
sites, as well as beneficial uses of dredged material are being developed by the LTMS.
An ODMDS is required to fulfill the LTMS objective of a range of disposal options for
sediments dredged from San Francisco Bay. Presently, no ocean disposal site is available to
accept this dredged material. Maintenance dredging of channels and expansion of dock capacities
are essential to sustain economic growth and strategic use of the ports. An estimated six
million yd3 per year of dredged material could be disposed at the designated site over the next
50 years.
S-l
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38°N -
37°30'N -
CordeOBank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marine Sanctuary
200m _ „
Faratton
< Islands
San
Frana'sco
Bay
t
Alternative
SiteS
•»„,»* Study
AreaS
Gumdrop
Seamount
> Pioneer
ICanyon
Zone of
Siting Feasibility
[ZSF Range)
(53 nmi)
Monterey Bay
National Marine
Sanctuary
-123°w
-122°30'w
Figure S-l. Locations of Study Areas and Alternative Sites in the LTMS Study Region.
AK0154
S-2
-------
The specific goal of this EIS is to provide an acceptable ocean disposal site which will not cause
unreasonable degradation of the ocean with respect to human health and the marine environment.
Other non-ocean alternatives are being addressed by the LTMS In-Bay Work Group and the
Nonaquatic/Reuse Work Group.
The proposed action is to designate Alternative Site 5 (Figure S-l) as the ODMDS to receive
dredged material from San Francisco Bay, in accordance with LTMS objectives. The designated
site can only be used for the disposal of dredged material from Federal projects and permit
applications that meet EPA and COE criteria and regulations. The site will not be used for
disposal of industrial or municipal wastes.
Five general and eleven specific site selection criteria (40 CFR 228) were used in the
determination process to evaluate three alternative ocean disposal sites:
• Alternative Site 5 (Preferred Alternative),
• Alternative Site 3, and
• Alternative Site 4.
Information contained in this EIS is used to characterize the physical, biological, and
socioeconomic environments (Section S.2) and evaluate the potential environmental consequences
of dredged material disposal at the preferred and alternative sites (Section S.3). The
environmental characteristics and potential disposal-related impacts are compared and evaluated
according to the five general and eleven specific site selection criteria (Section S.4).
S.2 Affected Environment
The following sections summarize the physical, biological, and socioeconomic environments of
the preferred and alternative sites.
S-3
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S.2.1 Physical Environment
The preferred and alternative ocean disposal sites are located on the continental slope and rise
off San Francisco (Figure S-l). The size and configuration of the sites are uniform with an oval
shape of dimensions of approximately 3.7 nmi (6.9 km) long and 2.2 nmi (4.1 km) wide.
Alternative Site 3 is located in the western part of Study Area 3 (depths ranging between 1,400
and 1,900 m ), south of the Gulf of the Farallones National Marine Sanctuary (GOFNMS), north
of Pioneer Canyon, and approximately 47 nmi from the Golden Gate. Alternative Site 4 is
located in the southwestern part of Study Area 4 (depths ranging between 1,900 and 2,100 m),
approximately 55 nmi from the Golden Gate and 15 nmi SE of Pioneer Seamount. Alternative
Site 5, the preferred alternative, is located on the continental rise (depths between 2,500 and
3,000 m), approximately 49 nmi from coast and 50 nmi from the Golden Gate.
The coastal environment off San Francisco has a maritime climate, characterized by a general
lack of weather extremes, with cool summers and mild, wet winters. Fog occurs off the coast
throughout the year, but is most persistent during summer. Winds are an important influence on
water column characteristics and currents over the continental shelf and upper continental slope.
Strong north and northwest winds in spring and early summer promote offshore-directed flow of
surface waters and upwelling.
Current flow in the vicinity of Alternative Site 3 is primarily to the northwest in the upper 800
to 900 m of the water column, although periodic reversals in flow occur. Currents below 1,000
m are generally weaker than near-surface currents, while near-bottom flows are enhanced by tidal
influences and topography. Similar trends in current flows occur in Alternative Sites 4 and 5.
Considerable seasonal variability in surface water temperature and salinity reflect large-scale
current patterns, outflow from the Bay, and small-scale flow features. Although the site-specific
data are limited, the existing water quality conditions at all alternative sites likely are similar,
with comparable dissolved oxygen, suspended particle, and trace chemical constituent
concentrations and turbidity levels.
S-4
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Sediments at Alternative Site 3 are mostly silt-sized particles, while sediments at Alternative
Site 4 comprise mostly sand and silt-sized particles, and sediments at the preferred alternative
comprise mainly fine-grained silts and clays. All of the sites are characterized by background
or low concentrations of chemical constituents. No known hard-bottom areas occur within any
of the sites.
5.2.2 Biological Environment
The preferred alternative site is characterized by somewhat lower infaunal diversity and
abundance than Alternative Sites 3 or 4. The number of species and abundances of megafaunal
invertebrates at Alternative Site 5 is moderate, with sea cucumbers, brittlestars, and sea pens
predominating. Some species of midwater fishes, such as juvenile rockfishes, have higher
seasonal abundances at the preferred alternative than at Alternative Sites 3 or 4. Based on
limited data on plankton communities and other midwater species, there do not appear to be any
significant differences among the sites. The preferred alternative site has relatively high use by
marine birds and mammals as compared to the alternative sites.
Alternative Site 3 is characterized by a diverse and abundant infaunal community comprising of
polychaetes, amphipods, tanaids, and isopods. Abundances and species diversity for megafaunal
invertebrates is moderate at this site, with sea cucumbers, seastars, and brittle stars
predominating. Juvenile rockfishes are seasonally abundant, while marine birds and mammals
make moderate use of this site.
Alternative Site 4 is characterized as having a very similar infaunal species composition as
Alternative Site 3, but with fewer amphipods. This site also has moderate numbers of species
and abundances of megafaunal invertebrates. Juvenile rockfishes use this site seasonally, while
marine birds and mammals utilize this site less than Alternative Site 3.
S-5
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5.2.3 Socioeconomic Environment
The region off San Francisco supports important commercial and recreational fisheries, consisting
of a variety of pelagic and demersal fishes and megafaunal invertebrates. However, use of the
preferred or alternative sites for commercial and recreational fisheries is minimal due to the great
depths and limited resource value. Pelagic fishes collected in the vicinity of the sites consist
mainly of tunas, mackerels, and some salmon, while demersal fishes consist primarily of
flatfishes, such as Dover sole, and rockfishes such as thornyheads.
The area offshore of San Francisco is one of the nation's largest naval operating zones.
However, none of the alternative sites are located within submarine operating areas or
navigational lanes. The potential for conflicts with oil and gas development at alternative sites
is extremely low. Although large repositories of oil and gas reserves are located in several areas
along and offshore of the California coast, there are no existing or planned oil and gas
development activities or structures within the general study region. Current technological
limitations preclude such activities at depths greater than approximately 400 m, while bottom
depths at the preferred and alternative sites are all greater than 1,400 m. Further, there are no
known features of cultural or historical significance within the sites.
S.3 Environmental Consequences
Potential environmental consequences associated with dredged material disposal at the preferred
and alternative sites are summarized in Table 4.1-1 (Chapter 4). The impact category and spatial
and temporal extents of potential impacts to specific environmental conditions are identified in
the table.
Evaluations of potential effects from dredged material disposal on air quality, on water quality
parameters (suspended particle concentrations), and on seafloor conditions (bottom deposit
thicknesses) were performed using computer models to simulate disposal at the preferred and
alternative sites. Additional information concerning environmental impacts obtained from
S-6
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research and monitoring of other dredged material disposal sites also was used to evaluate
potential impacts at these sites.
S.3.1 Physical Environment
Impacts from dredged material disposal operations on air quality, water quality, and geology are
considered insignificant. Exhaust emissions from dredged material transport operations would
not result in concentrations of air pollutants that exceed State and Federal standards. The water
quality model predicted a low probability that fine-grained sediments would reach the boundary
of any of the National Marine Sanctuaries following disposal at any of the alternative sites.
Therefore, potential effects on water quality are considered insignificant. A sediment deposition
model predicted that, within the boundaries of the preferred and alternative sites, areas covered
by deposits with thicknesses greater than or equal to 10 cm (100 mm), would be less than
10 km2. Depending on the characteristics of the dredged material, significant localized changes
in the grain size of the bottom sediments could be expected in areas with the highest deposition.
However, according to the deposition model calculations, no measurable deposition and alteration
of bottom sediments would occur within the sanctuaries. Significant impacts on sediment quality
in any area are not expected given that the dredged material must be tested and determined
suitable, according to EPA and COE testing criteria, for disposal in the ocean.
5.3.2 Biological Environment
Impacts on infauna, epifauna, and fishes at deep-water sites are expected to occur over a wider
area than at shallow shelf sites because of greater sediment dispersal in the water column before
it reaches the bottom. The benthic community would be similarly affected by dredged material
disposal at the preferred or alternative sites as a result of smothering of some organisms and
alteration of sediment characteristics. However, these impacts are expected to occur only in areas
with depositional thicknesses equal to or greater than 10 cm. Areas with depositional thicknesses
less than 10 cm would not be expected to incur significant changes in abundance or diversity of
infauna, epifauna, or demersal fishes. Impacts on water column organisms such as plankton,
S-7
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pelagic fishes, pinnipeds and cetaceans are expected to be minimal and temporary at the preferred
and alternative sites. Further, exposure of marine organisms to dredged material is not expected
to result in significant effects because all dredged material must be approved by EPA and COE
before disposal.
S.3.3 Socioeconomic Environment
At the preferred and alternative sites, it is unlikely that dredged material disposal will interfere
with other ocean uses, including shipping, fishing, and recreation. The effects of disposal
activities on commercial and recreational fishing are expected to be temporary and insignificant.
Most disposal impacts will occur near the sea bottom, and no significant demersal fisheries exist
within any of the alternative sites.
Potential hazards to commercial and recreational navigation resulting from dredged material
transport and disposal are expected to be minimal at the preferred and alternative sites. Dredged
material barge transits to the preferred alternative site could cause some interference with
commercial, recreational, and scientific boat traffic, particularly near the Farallon Islands.
However, this could be mitigated by specifying barge transit routes that avoid the vicinity of the
Islands. No existing or planned oil and gas development activities occur within the region.
Therefore, dredged material disposal will not affect oil and gas development. Disposal activities
at the preferred or alternative sites should not pose a significant danger or cause interference with
military vessels because the number of dredged material barge trips is small compared to the
overall volume of vessel traffic in the region.
No known cultural or historical resources exist within the preferred or alternative sites.
Therefore, dredged material disposal would not affect cultural resources. Potential impacts on
human safety should be very low because the number of barge trips is small compared to the
overall volume of traffic, and measures such as specifying barge transit routes would avoid
interference in the vicinity of the Farallon Islands. As stated in MPRSA, no materials considered
S-8
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to be hazardous may be disposed at an ODMDS. Therefore, the potential for human health
hazards is minimal at all the sites.
S.4 Comparison of the Alternative Ocean Disposal Sites With the 5 General and
11 Specific Site Selection Criteria
The preferred alternative (Alternative Site 5) and the two alternative disposal sites (Alternative
Sites 3 and 4) are compared to the 5 general criteria listed at 40 CFR 228.5 and the 11 specific
site selection criteria listed at 40 CFR 228.6(a). A detailed summary of the 11 site selection
criteria is contained in Table 2.2-1 (Chapter 2).
S.4.1 General Selection Criteria
1. The dumping of materials into the ocean will be permitted only at sites or in
areas selected to minimize the interference of disposal activities with other
activities in the marine environment, particularly avoiding areas of existing
fisheries or shellfisheries, and regions of commercial or recreational
navigation.
The preferred and alternative sites are located in water depths greater than 1,400 m, characterized
by sparsely distributed fisheries species of potential commercial value. Use of the sites for
dredged material disposal would have minimal effects on existing or potential fisheries or
shellfisheries. None of the sites is located within established precautionary zones, navigation
lanes, or submarine operating areas. The additional vessel traffic represented by dredged material
barge transits to the alternative sites is considered small compared to overall traffic volumes,
therefore representing a negligible potential impact on commercial or recreational navigation.
S-9
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2. Locations and boundaries of the disposal sites will be so chosen that
temporary perturbations in water quality or other environmental conditions
during initial mixing caused by disposal operations anywhere within the site
can be expected to be reduced to normal ambient seawater levels or to
undetectable concentrations or effects before reaching any beach, shoreline,
marine sanctuary, or known geographically limited fishery or shellfishery.
The preferred and alternative sites are outside of any sanctuary boundaries. Modeling results
indicated low probabilities of material disposed of at the alternative sites being transported into
the National Marine Sanctuaries. Further, predicted dilution rates would reduce the suspended
particle concentrations to normal ambient levels at the sanctuary boundaries. Similarly, use of
the alternative sites is unlikely to affect water quality or other environmental conditions at any
beach, shoreline, or resource or amenity area due to the large distances offshore and the ability
to specify dredged material barge transit routes, to avoid resources associated with the Farallon
Islands.
3. If at any time during or after disposal site evaluation studies, it is determined
that existing disposal sites presently approved on an interim basis for ocean
dumping do not meet the criteria for site selection set forth in Sections 228.5
through 228.6, the use of such sites will be terminated as soon as suitable
alternate disposal sites can be designated.
Continued use of a designated disposal site will be evaluated as part of the site management and
monitoring program.
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4. The sizes of ocean disposal sites will be limited in order to localize for
identification and control any immediate adverse impacts and permit the
implementation of effective monitoring and surveillance programs to prevent
adverse long-range impacts. The size, configuration, and location of any
disposal site will be determined as a part of the disposal site evaluation or
designation study.
The sizes and configurations of the preferred and alternative sites are based on the result of water
quality and deposition modeling studies. Site size will be limited, yet will encompass modeled
regions of significant sediment deposition (i.e., 10 mm). The site locations are chosen to
coincide with depositional zones where resuspension and dispersion of dredged material will be
minimized and monitoring of long-term effects will be facilitated.
5. EPA will, wherever feasible, designate ocean dumping sites beyond the edge
of the continental shelf and other such sites that have been historically used.
All of the alternative sites are located beyond the edge of the continental shelf. Historical
disposal operations of low-level radioactive wastes and chemical and conventional munitions have
occurred in the general vicinity of the preferred alternative. Additionally, the U.S. Navy is
seeking a project-specific permit for disposal of approximately 1.6 million yd3 in a location that
corresponds to the preferred alternative. In contrast, no historical waste disposal has occurred
at Alternative Sites 3 and 4.
S.4.2 Specific Site Selection Criteria
I. Geographical position, depth of water, bottom topography, and distance from
coast.
The preferred alternative (Alternative Site 5) is located on the continental rise at depths ranging
between 2,500 and 3,000 m, with a moderately sloping bottom that is relatively unbounded,
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Alternative Sites 3 and 4 are located in shallower depths on the lower continental slope. All sites
are located at least 45 miles from the Golden Gate.
2. Location in relation to breeding, spawning, nursery, feeding, or passage areas
of living resources in adult or juvenile stages.
The preferred and alternative sites contain low numbers of fish species and abundances (as
compared to inshore areas) and moderate numbers of megafaunal invertebrate species and
abundances. The preferred alternative has higher use by some organisms, such as marine birds
and mammals and some midwater fishes, but relatively lower diversity and abundances of infauna
as compared to Alternative Sites 3 and 4.
3. Location in relation to beaches and other amenity areas.
All sites are located at least 45 nmi from any coastal resources and at least 10 nmi from any
National Marine Sanctuaries. Based on water quality modeling results, concentrations of
sediment particles transported across Sanctuary boundaries will be within the range of normal
background levels.
4. Types and quantities of wastes proposed to be disposed of, and proposed
methods of release, including methods of packing the waste, if any.
Up to 6 million yd3 per year of predominantly silt and clay material dredged from San Francisco
Bay could be disposed at the ODMDS. Disposal most likely will be from split hull barges. The
total amount of dredged material disposed over a 50-year period could total 400 million yd3. No
dumping of toxic materials or industrial or municipal wastes would be allowed at the site.
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5. Feasibility of surveillance and monitoring.
The USCG has surveillance responsibility at the designated site. Physical, chemical, and
biological sampling is possible at all alternative sites. However, the preferred alternative is the
deepest site and, therefore, may be more difficult to monitor as compared to Alternative Sites 3
and 4. Additionally, monitoring activities at the preferred alternative site may require special
precautions due to previously disposed waste materials.
6. Dispersal, horizontal transport, and vertical mixing characteristics of the
area, including prevailing current direction and velocity, if any.
At all the sites, ocean currents flow primarily to the northwest in the upper 800 to 900 m of the
water column, although periodic reversals in flow occur. Currents below 1,000 m are generally
weaker than near-surface currents. Near-bottom currents may be enhanced by tidal influences
and topography. Sediment resuspension and transport is 'expected to be minimal within all the
alternative sites.
7. Existence and effects of current and previous discharges and dumping in the
area (including cumulative effects).
No current disposal activities occur within the preferred or alternative sites. However, the Navy
has requested an MPRSA Section 103 permit for disposal of up to 1.6 million yd3 of dredged
material at the preferred alternative site. In addition, disposal of radioactive waste containers was
conducted between 1951 and 1954 in the vicinity of Study Area 5. Chemical and conventional
munitions were disposed from approximately 1958 to the late 1960s at the Chemical Munitions
Dumping Area, within which the preferred alternative is located. No residual contamination from
either source was detected during recent surveys and disposal of dredged material is unlikely to
have any synergistic or additive effects. Dredged material disposal may, in fact, serve to isolate
any residual contamination.
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8. Interference with shipping, fishing, recreation, mineral extraction,
desalination, fish and shellfish culture, areas of special scientific importance
and other legitimate uses of the ocean.
Dredged material barge transit to the preferred alternative site could cause minor interference
with recreation and scientific boat traffic in the vicinity of the Farallon Islands. However, under
normal conditions, no interference is expected. A requirement that barges avoid the Farallones
vicinity could minimize potential impacts. Further, no significant interferences with fishing or
shipping would be expected at the preferred alternative site. The potential for interference of
dredged material disposal with shipping, fishing, recreation, and areas of special scientific
importance also would be minimal at Alternative Sites 3 and 4.
9. Existing water quality and ecology of the site as determined by available data,
by trend assessment, or by baseline surveys.
The water quality conditions at the preferred and alternative sites likely are similar. Sediments
at all the sites contain low to background concentrations of trace metal and organic contaminants.
Ecological characteristics are discussed under site-specific criterion 2. Potential impacts at any
of the sites are expected to be transitory and insignificant.
10. Potentiality for the development of nuisance species at the disposal site.
It is unlikely that nuisance species would recruit to any of the sites due to dredged material
disposal. This is based on the significant differences in depth and environment at the preferred
and alternative sites compared to the dredging site(s).
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11. Existence at or in close proximity to the site or any significant natural or
cultural features of historical importance.
There are no known significant natural or cultural features within or in the vicinity of any of the
alternative sites.
S.5 Conclusions
Impacts from disposal of dredged material at the preferred alternative are expected to be minimal
for the following reasons:
Bathymetric and sediment surveys indicate Alternative Site 5 is located in a
depositional area which, because of topographic containment features, is likely
to retain dredged material which reaches the sea floor;
No significant impacts to other resources or amenity areas (e.g., marine
sanctuaries) are expected to occur from designation of Alternative Site 5;
Existing and potential fisheries resources within Alternative Site 5 are minimal
and this site is removed from important fishing grounds located nearer to
Alternative Sites 3 and 4;
Densities and biomass of demersal fishes and megafaunal invertebrates are
estimated to be relatively low compared to those at Alternative Sites 3 and 4;
Potential impacts to other organisms (e.g., marine birds and mammals and
midwater organisms) are expected to be insignificant, even though Alternative
Site 5 tends to have slightly higher abundances of these organisms; and
Waste disposal has occurred historically in the vicinity of the site (and
disposal of dredged material may occur as part of the Navy MPRSA Section
103 project).
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CHAPTER 1
INTRODUCTION
1.1 General Introduction
This Draft Environmental Impact Statement (DEIS) evaluates the proposed designation of a
deep-water ocean dredged material disposal site (ODMDS) off San Francisco, California. A
variety of maintenance dredging and new channel and harbor deepening projects proposed for
San Francisco Bay will generate material that will be evaluated for disposal at the ODMDS (COE
1992a). The proposed ODMDS could receive up to 6 million cubic yards (yd3) of sediments per
year over the next 50 years (COE 1991).
Sediment dredging and disposal are regulated under two federal laws: Title I of the Marine
Protection, Research and Sanctuaries Act (MPRSA), and Section 404 of the Clean Water Act
(CWA). Both Acts require that a number of alternative methods, including ocean disposal, be
evaluated for environmental acceptability prior to disposal. The U.S. Environmental Protection
Agency (EPA) and the U.S. Army Corps of Engineers (COE) share responsibility for the
management of ocean disposal of dredged material. Under Section 102 of MPRSA, EPA has the
responsibility for designating an acceptable location for the ODMDS. With concurrence from
EPA, the COE issues permits under MPRSA Section 103 for ocean disposal of dredged material
deemed suitable according to EPA criteria in MPRSA Section 102 and EPA regulations in 40
CFR Part 227.
It is EPA's policy to publish an Environmental Impact Statement (EIS) for all ODMDS
designations (39 FR 37119, October 21, 1974). A site designation EIS is a formal evaluation of
alternative sites in which the potential environmental impacts associated with disposal of dredged
material at various locations are examined. The EIS must first demonstrate the need for the
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proposed ODMDS designation action (40 CFR §6.203(a) and 40 CFR §1502.13) by describing
available or potential aquatic and nonaquatic (i.e., land-based) alternatives, and the consequences
of not designating a site—the No-Action Alternative. Once the need for an ocean disposal site
is established, potential sites are screened for feasibility through the Zone of Siting Feasibility
(ZSF) process. Remaining alternative sites are evaluated using EPA's ocean dumping criteria at
40 CFR Part 228 (Table 1.1-1) and compared in the EIS. Of the sites which satisfy these criteria,
the site which best complies with these criteria is selected as the preferred alternative for formal
designation through rulemaking published in the Federal Register.
Formal designation of an ODMDS in the Federal Register does not constitute approval for ocean
disposal. Designation of an ODMDS provides an ocean disposal alternative for consideration in
the review of each proposed dredging project. Ocean disposal is allowed only when EPA and
COE determine that the proposed activity is environmentally acceptable according to the criteria
at 40 CFR Part 227. Decisions to allow ocean disposal are made on a case-by-case basis through
the MPRSA Section 103 permitting process.
Upon application for a permit, an evaluation process, shown diagrammatically in Figure 1.1-1,
ensures that the proposed disposal operation conforms to the provisions of EPA's Ocean
Dumping Regulations (40 CFR Parts 220, 225, 227-228) and COE's dredged material disposal
permit requirements under MPRSA Section 103 (33 CFR Parts 320-330 and 335-338). Material
proposed for disposal at the designated ODMDS must conform to EPA's permitting criteria for
acceptable quality (40 CFR Parts 225 and 227), as determined from physical, chemical, and
bioassay/bioaccumulation testing (EPA and COE 1991). Permits to use a designated ODMDS
also can specify the times, rates, and methods of disposal, as well as the quantities, types, and
sources of the dredged material.
1.2 Purpose of and Need for Action
The purpose of the proposed action is to provide an ocean disposal site for sediments dredged
from San Francisco Bay. Dredging is required to remove millions of cubic yards of accumulated
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Table 1.1-1. Five General and Eleven Specific Site Selection Criteria.
General Site Selection Criteria—40 CFR 228.5
(a) The dumping of materials into the ocean will be permitted
only at sites or in areas selected to minimize the interference
of disposal activities with other activities in the marine
environment, particularly avoiding areas of existing fisheries
or shellfisheries, and regions of heavy commercial or
recreational navigation.
(b) Locations and boundaries of disposal sites will be so chosen
that temporary perturbances in water quality or other
environmental conditions during initial mixing caused by
disposal operations anywhere within the site can be expected
to be reduced to normal ambient seawater levels or to
undetectable contaminant concentrations or effects before
reaching any beach, shoreline, marine sanctuary, or known
geographically limited fishery or shellfishery.
(c) If at any time during or after disposal site evaluation studies,
it is determined that existing disposal sites presently approved
on an interim basis for ocean dumping do not meet the
criteria for site selection set forth in Sections 228.5 through
228.6, the use of such sites will be terminated as soon as
suitable alternate disposal sites can be designated.
(d) The sizes of the ocean disposal sites will be limited in order to
localize for identification and control any immediate adverse
impacts and permit the implementation of effective
monitoring and surveillance programs to prevent adverse
long-range impacts. The size, configuration, and location of
any disposal site will be determined as a part of the disposal
site evaluation or designation study.
(e) EPA will, wherever feasible, designate ocean dumping sites
beyond the edge of the continental shelf and other such sites
that have been historically used.
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Table 1.1-1. Continued.
Specific Site Selection Criteria-^0 CFR 228.6(a)
(1) Geographical position, depth of water, bottom topography,
and distance from the coast;
(2) Location in relation to breeding, spawning, nursery, feeding,
or passage areas of living resources in adult or juvenile
phases;
(3) Location in relation to beaches and other amenity areas;
(4) Types and quantities of wastes proposed to be disposed of,
and proposed methods of release, including methods of
packaging the waste, if any;
(5) Feasibility of surveillance and monitoring;
(6) Dispersal, horizontal transport and vertical mixing
characteristics of the area, including prevailing current
direction and velocity, if any;
(7) Existence and effects of current and previous discharges and
dumping in the area (including cumulative effects);
(8) Interference with shipping, fishing, recreation, mineral
extraction, desalination, fish and shellfish culture, areas of
special scientific importance and other legitimate uses of the
ocean;
(9) Existing water quality and ecology of the site as determined
by available data or by trend assessment or baseline surveys;
(10) Potentiality for the development or recruitment of nuisance
species in the disposal site; and
(11) Existence at, or in close proximity to, the site of any significant
natural or cultural features of historical importance.
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Applicant or COE Proposes Dredging Project -
Need For Ocean Disposal Established
COE District Engineer Publishes Public Notice with Data
Review by EPA Regional Office and Public
EPA Notifies COE of Compliance
With EPA Dumping Criteria
(Submits Special Conditions
for the Permit)
EPA Notifies District Engineer of
Non-Compliance of Material
With EPA Criteria
District Engineer
Re-Evaluates Alternatives
Feasible Alternatives Available
No Feasible Alternative
Inform EPA Administration
and Chief of Engineers
Chief of Engineers
Considers Alternatives
No Feasible Alternative,
Requests Waiver
EPA Administrator
Considers Waiver
Secretary of Army Seeks
Waiver From EPA
AK0060
Figure 1.1-1. Evaluation Process for Dredged Material Permits.
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sediments transported by natural processes into San Francisco Bay (COE 1992b). In depositional
areas with weak currents, these sediments settle to the bottom, accumulate, and gradually cause
portions of the Bay to become shallower. Sediment deposition and accumulation, particularly
in the navigation channels and port facilities, may seriously interfere with vessel traffic, vessel
loading and unloading, and vessel mooring or storage.
Dredging is needed to maintain over 85 miles of authorized deep and shallow navigation channels
in San Francisco Bay that provide vessel access to commercial, recreational, and fishing facilities.
The COE (1990a) stated that:
"Navigation channel maintenance and improvements are essential to the nation's
ability to compete effectively in international import/export markets. The San
Francisco Bay and estuary act as a critical thoroughfare for the nation's increasing
role in Pacific Rim Trade with its numerous ports and intermodal links. As of
1983, the San Francisco Bay Area was the fifth largest export manufacturing
center in the United States with export-related employment of over 68,000 and a
dollar value of close to 7 billion dollars (Skinkle, 1989). In 1980, trade with the
Pacific Rim nations (Japan, Korea, Taiwan, Australia and other countries in the
Far East) accounted for one-quarter of the nation's imports/exports—today the
share is over one-third and rising (Skinkle, 1989)."
Furthermore, the COE (1992a) concluded that:
"Dredging needs to continue in order to provide adequate depths for deep and
shallow draft vessels serving the commercial and recreational needs of the Bay.
Over 4,000 deep draft vessels annually call at container ports, oil and auto
facilities, bulk terminals and other facilities throughout the Bay and the inland
ports of Sacramento and Stockton. The U.S. Navy and Coast Guard maintain a
major presence in the Bay Area and many of their facilities require dredging.
Dredging is also required to maintain the depths necessary for shallow draft
vessels serving recreational boaters, tourists and ferry riders, commercial fishing
and miscellaneous other activities."
Under the Rivers and Harbors Act of 1889, as amended (33 USC Sections 401 et seq.\ the COE
is responsible for maintaining the navigability of major waterways. The COE's maintenance
dredging operations throughout the Bay comprise 13 civil works projects that historically have
generated approximately 5 million yd3 per year of dredged material. Other channel-deepening
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and new work projects have been proposed that would generate additional volumes of dredged
material. The annual and projected 50-year volumes for dredging projects within San Francisco
Bay are 7.6 million yd3 and approximately 400 million yd3, respectively (Table 1.2-1; COE
1992a). Approximately 6 million yd3 of the 7.6 million yd3 annual volume is under consideration
for disposal at the ODMDS.
Disposal options, including the use of sites within the Bay, nonaquatic sites, and ocean disposal
sites, as well as beneficial uses of dredged material are being evaluated as components of the
Long-Term Management Strategy (LTMS) for San Francisco Bay (COE 1992a). The goal of the
LTMS is "to secure timely, technically feasible, cost-effective, and environmentally acceptable
disposal alternatives for dredged material." Evaluations of these alternatives are scheduled for
completion in 1994. The LTMS envisions that several options will be available for disposal,
depending on the volumes and characteristics of the dredged material and the location of the
dredging project. Disposal options are necessary because it is unlikely that a single site can
satisfactorily accommodate the planned volumes and characteristics of the dredged material
(COE 1990a).
Historically, most sediments dredged from the Bay have been disposed at sites within the Bay.
The primary disposal site within the Bay, the Alcatraz Site, is mounding due to previous disposal
practices (COE 1992a). Due to present mounding problems and concerns about potential effects
of dredged material disposal on fisheries resources, water quality, and habitat alteration,
restrictions have been placed on the use of sites within the Bay (COE 1990a). The present
capacities of existing sites within the Bay for dredged material disposal are unknown (COE
1990a). The feasibility of dredged material disposal at sites within the Bay is being evaluated
by the LTMS In-Bay Work Group.
Nonaquatic sites also have been used historically for the disposal of dredged material from the
Bay. Dredged material has been used primarily as fill at these sites, although disposal at
nonaquatic sites also can have beneficial effects, such as marsh restoration, creation of wetlands,
and levee maintenance. However, nonaquatic sites generally have limited -capacities, and
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Table 1.2-1.
Projected Annual and 50-Year Dredging Volumes for Projects in San
Francisco Bay. Dredging Volumes in Cubic Yards.
Project
COE Maintenance
John F. Baldwin
New Work
Oakland New Work
Richmond New Work
Navy Maintenance
Navy New Work
Oakland Permit"
San Francisco
Permit"
Chevron Permit"
Other Permit"
TOTAL
Annual
Volume
4,276,000
1,780,000
140,000
200,000
196,000
1,040,000
7,632,000
50-Year
LTMS Volume
213,800,000*
9,000,000
7,000,000
1,500,000
89,000,000
1,700,000
7,000,000
10,000,000
9,800,000
52,000,000
400,800,000 *
Source: COE 1992a
Includes maintenance dredging volumes from new work projects (T. Wakeman, COE, pers. comm. 1992).
"Permit projects are non-Congressionally authorized projects that may include maintenance or new work
dredging (T. Wakeman, COE, pers. comm. 1992).
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presently no sites are available to accommodate the large volume of material projected to be
dredged from San Francisco Bay (COE 1992a). Also, the high costs associated with land
acquisition and transport, constraints against filling wetlands, and a variable and vaguely defined
permitting process complicate the selection of nonaquatic areas as disposal sites (COE 1990a).
The feasibility of dredged material disposal at nonaquatic sites is being evaluated by the LTMS
Nonaquatic/Reuse Work Group. Given the lack of capacity at sites within the Bay and
nonaquatic sites, the COE (1990a) concluded that "clearly, there exists a shortfall in disposal
capacity for the improvement projects scheduled by the USAGE [COE], the Navy and the ports
for this region."
Presently no ocean disposal site is available to accept dredged material from San Francisco Bay.
The Channel Bar Site is a designated ODMDS [40 CFR 228.12(b)(14)]; however, only coarse-
grained sediments dredged from the entrance channel to San Francisco Bay are permitted for
disposal. Most sediments from San Francisco Bay are fine-grained and, therefore, are not
suitable for disposal at the Channel Bar ODMDS (EPA 1982). Thus, although the goal of the
LTMS is to provide a range of options that include ocean disposal, presently no ODMDS is
available. Designation of an ODMDS for large quantities of dredged material from San
Francisco Bay is considered an integral component of the LTMS (COE 1992a). The California
State Water Resources Control Board's (SWRCB) resolution 90-37 "places all dredging parties
and agencies on notice that failure to reach specific commitments for designation of [such] an
ocean disposal site in a timely manner will result in the State Board exercising its full authority
regarding water quality certification [for disposal within the Bay]..." The feasibility of dredged
material disposal at an ODMDS is being evaluated by the LTMS Ocean Studies Work Group.
1.3 Proposed Action
The proposed action is the designation of a deep-water ODMDS that could be used for disposal
of sediments dredged from San Francisco Bay. This DEIS evaluates three alternative disposal
sites according to the five general and eleven specific criteria promulgated at 40 CFR §228
(Table 1.1-1) and recommends the preferred alternative. The locations of the alternative disposal
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sites are shown in Figure 1.3-1. Alternative Sites 3, 4, and 5 are located within LTMS Study
Areas 3, 4, and 5, respectively. Alternative Site 5 is the preferred alternative.
Study Areas 3, 4, and 5 are located off the continental shelf. Study Area 3 is south of the Gulf
of the Farallones National Marine Sanctuary (GOFNMS), north of Pioneer Canyon, and
approximately 47 nautical miles (nmi) from the Golden Gate. Study Area 4 is south of Pioneer
Canyon, 55 nmi from the Golden Gate, and between two former explosives disposal areas. Study
Area 5 is south of the Cordell Bank National Marine Sanctuary (CBNMS), adjacent to the
western side of the GOFNMS, and approximately 50 nmi from the Golden Gate. This study area
contains low-level radioactive waste and chemical munitions. Study areas were selected through
a screening process which considered proximity to marine sanctuaries and designated areas of
special biological significance, vessel traffic lanes, submarine operating areas, Pioneer Canyon,
areas with significant hard-bottom features, and sites used historically for disposal of chemical
munitions, explosive munitions, and low-level radioactive wastes (EPA 1991; see Chapter 2).
Alternative sites within each of Study Areas 3, 4, and 5 were delineated from the results of EPA
surveys at Study Areas 3 and 4 (SAIC 1992b,c) and EPA and Navy surveys at Study Area 5
(SAIC 1992a). These results are summarized in Chapter 3. Specific portions of these study
areas that are characterized as low-energy, depositional zones containing sediments which are
similar in grain size to those within the Bay were selected as alternative sites. These conditions
are considered important for minimizing dispersion of dredged material and minimizing the area
of potential impacts. The site sizes and positions of the site boundaries were determined by
modeling the fate of dredged material based on simulated discharges over a one-year period (see
Chapter 4).
No alternative sites are considered for Study Areas 1 or 2. Study Area 1 corresponds to the
Channel Bar ODMDS; however, as noted above and discussed in Chapter 2 of this DEIS, Study
Area 1 was dropped from further consideration as an alternative for disposal of dredged material
from San Francisco Bay. Study Area 2 is located on the continental shelf, in depths shallower
than 180 meters (m), and adjoins the boundary of the GOFNMS. This study area also was
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38°N -
37°30'N -
CordeilBank /
National Marine t
Sanctuary
Transverse Mercator Projection
Scale
o 5 10 is 20
Gulf of The Farallpnes
National Marine Sanctuary
200m
Farallon
. Islands
"..,.San ...
Francisco
V
San
Francisco
Bay
Alternative
Sites
Alternative
Site 3
\ Pioneer
VCanyon
Monterey Bay
National Marine
Sanctuary
-123°30Vv
-123°w
-122°30>w
Figure 1.3-1.
Locations of Study Areas 1 Through 5 and Alternative Sites 3,4, and 5 in
the LTMS Study Region.
The 50m, 200m, 500m, 1,500m, and 2,500m contours correspond to the 28,110, 275, 825, and
1,375 fathom contours, respectively.
AK0061
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dropped from further consideration because it lies within the boundaries of the Monterey Bay
National Marine Sanctuary (MBNMS). The Final Rule for MBNMS designation prohibits
dredged material disposal at any new ODMDS within the Sanctuary boundaries. Therefore, EPA
will not pursue designation of an ODMDS within the MBNMS.
1.4 Areas of Controversy
This section summarizes issues raised during the Public Scoping Meeting, the scoping period, and
the LTMS public involvement process (Chapter 5). The general areas of controversy include:
Proximity of the ODMDS to national marine sanctuaries (NMSs), areas of hard
bottom, and Pioneer Canyon;
Potential interferences with existing and/or future fisheries resources, and to
feeding, breeding, and migratory activities of marine birds and mammals;
Potential impacts to other water column organisms should particles remain
suspended;
Potential problems predicting the area affected by disposal operations; and
Potential problems monitoring short- and long-term effects from disposal
operations at a deep-water disposal site.
An additional area of controversy involves the relationship of the ODMDS to the MBNMS. The
continental shelf area from the Gulf of the Farallones to Cambria is encompassed by the
MBNMS. This Sanctuary includes all of Study Area 2 and the eastern (shallow) portion of Study
Area 3, and precludes the use of these areas as an ODMDS. Furthermore, the 12-mile wide zone
contiguous with the seaward boundary of the Sanctuary, as described in EPA site monitoring
regulations [40 CFR §228.10(c)(l)(i)], includes Alternative Sites 3, 4, and 5. Although the
National Oceanic and Atmospheric Administration (NOAA) will not regulate dredged material
within this zone (NOAA 1992), any site selected as an ODMDS may require a more intensive
monitoring effort because of its proximity to the Sanctuary resources.
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1.5 Issues To Be Resolved
Major issues discussed in the DEIS that will be resolved prior to publication of the Final EIS
include location, boundaries, and size of the site to be designated, monitoring objectives, and the
areas of controversy identified in Section 1.4.
1.6 Regulatory Framework
An international treaty and several laws, regulations, and orders apply to ocean disposal of
dredged material and to the designation of an ODMDS. The relevance of these statutes to the
proposed action and to related compliance requirements is described below.
1.6.1 International Treaty
The principal international agreement governing ocean disposal is the Convention on the
Prevention of Marine Pollution by Dumping of Wastes and Other Matter (26 UST 2403: TIAS
8165), also known as the London Dumping Convention (LDC). This agreement became effective
on August 30, 1975, after ratification by the participating countries, including the United States.
Ocean dumping criteria incorporated into MPRSA have been adapted from the provisions of the
LDC. Thus, material considered acceptable for ocean disposal under MPRSA also is acceptable
for ocean disposal under the LDC.
1.6.2 Federal Laws and Regulations
1.6.2.1 Marine Protection, Research and Sanctuaries Act of 1972, as amended
(33 USC Section 1401 et sea.}
The MPRSA regulates the transportation and ultimate disposal of material in the ocean, prohibits
ocean disposal of certain wastes without a permit, and prohibits the disposal of certain materials
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entirely. Prohibited materials include those which contain radiological, chemical, or biological
warfare agents, high-level radiological wastes, and industrial waste. MPRSA has jurisdiction over
all United States ocean waters in and beyond the territorial sea, vessels flying the U.S. flag, and
vessels leaving U.S. ports. The territorial sea is defined as waters three miles seaward of the
nearest shoreline. For bays or estuaries, the three-mile territorial sea begins at a baseline drawn
across the opening of the water body.
Section 102 of the Act authorizes EPA to promulgate environmental criteria for evaluation of all
dumping permit actions, to retain review authority over COE MPRSA 103 permits, and to
designate ocean disposal sites for dredged material disposal. EPA's regulations for ocean
disposal are published at 40 CFR Parts 220-229. Under the authority of Section 103 of the
MPRSA, COE may issue ocean dumping permits for dredged material if EPA concurs with the
decision. If EPA does not agree with a COE permit decision, a waiver process under Section
103 allows further action to be taken (Figure 1.1-1). The permitting regulations promulgated by
COE, under the MPRSA, appear at 33 CFR Parts 320 to 330 and 335 to 338. Based on an
evaluation of compliance with the regulatory criteria of 40 CFR Part 227, both EPA and COE
may prohibit or restrict disposal of material that does not meet the criteria. The EPA and COE
also may determine that ocean disposal is inappropriate because of ODMDS management
restrictions or because options for beneficial use(s) exist. Site management guidance is provided
in 40 CFR §228.7-228.11.
1.6.2.2 National Environmental Policy Act of 1969 (42 USC Section 4341 et sea.)
The National Environmental Policy Act (NEPA) was established to ensure that the environmental
consequences of federal actions were incorporated into Agency decision-making processes. It
establishes a process whereby the parties most affected by the impact of a proposed action are
identified and their opinions are solicited. The proposed action and several alternatives are
evaluated in relation to their environmental impacts, and a tentative selection of the most
appropriate alternative is made. A DEIS is developed which presents sufficient information to
evaluate the suitability of the proposed and alternative actions. A Notice of Availability,
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announcing that the DEIS can be obtained for comment, is published in the Federal Register.
After the DEIS comment period, the comments are addressed, revisions are made to the DEIS,
and the document is published as a Final EIS. A proposed rule is published with the FEIS. For
ODMDS designations, publication of a Final Rule in the Federal Register is equivalent to a
NEPA Record of Decision.
The Council on Environmental Quality (CEQ) has published regulations at 40 CFR Parts 1500
to 1508 for implementing NEPA. EPA NEPA regulations are published at 40 CFR Part 6. The
COE regulations for implementing NEPA are published at 33 CFR Part 220.
1.6.2.3 Clean Water Act of 1972 (33 USC Section 1251 et sea.)
The Clean Water Act (CWA) was passed to restore and maintain the chemical, physical, and
biological integrity of the Nation's waters. Specific sections of the Act control the discharge of
pollutants and wastes into aquatic and marine environments.
The major section of the CWA that applies to dredging activities is Section 401 which requires
certification that the permitted project complies with State Water Quality Standards for actions
within State waters. Under Section 301, states must establish Water Quality Standards for waters
in the territorial sea. Dredging or disposal of dredged material may not cause the concentrations
of chemicals in the water column to exceed State standards. To receive State certification, a
permit applicant must demonstrate that these standards will not be exceeded.
1.6.2.4 Clean Air Act as Amended (42 USC Section 1451 et sea.)
The Clean Air Act is intended to protect the Nation's air quality by regulating emissions of air
pollutants. The Act is applicable to permits and planning procedures related to dredged material
disposal within the territorial sea. It is not applicable to the proposed designation of an ODMDS.
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1.6.2.5 Fish and Wildlife Coordination Act of 1958 (16 USC Section 661 et sea.}
The Fish and Wildlife Coordination Act requires that water resource development programs
consider wildlife conservation. Whenever any body of water is proposed or authorized to be
impounded, diverted, or otherwise controlled or modified, the U.S. Fish and Wildlife Service
(FWS) and the State agency responsible for fish and wildlife must be consulted. Section 662(b)
of the Act requires federal agencies to consider recommendations based on the FWS
investigations. The recommendations may address wildlife conservation and development, any
damage to wildlife attributable to the project, and measures proposed for mitigating or
compensating for these damages. The Act is applicable to the evaluation of MPRSA Section 103
permits and other water resource development projects.
1.6.2.6 Coastal Zone Management Act of 1972 (16 USC Section 1456 et sea.}
Under the Coastal Zone Management Act (CZMA), any federal agency conducting or supporting
activities directly affecting the coastal zone must proceed in a manner consistent with approved
State coastal zone management programs, to the maximum extent practicable. If a proposed
activity affects water use in the coastal zone (i.e., the territorial sea and inland), the applicant
may need to demonstrate compliance with a state's approved CZMA program.
The Coastal Zone Reauthorization Amendments of 1990 (Section 6208) state that any federal
activity, regardless of its location, is subject to the CZMA requirement for consistency if it will
affect any natural resources, land uses, or water uses in the coastal zone. No federal agency
activities are categorically exempt from this requirement. As part of the designation process,
EPA will prepare a coastal consistency determination and will seek approval from the California
Coastal Commission (CCC). The CCC will continue to review permit applications for dredging
projects and federal determinations of consistency for federal dredging projects, including the
transport of dredged material through the coastal zone, for consistency with the California Coastal
Zone Management Plan (CZMP).
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1.6.2.7 Endangered Species Act of 1973 (16 USC Section 1531 et sea.}
The Endangered Species Act protects threatened and endangered species by prohibiting federal
actions which would jeopardize the continued existence of such species or which would result
in the destruction or adverse modification of any critical habitat of such species. Section 7 of
the Act requires that consultation regarding protection of such species be conducted with the
FWS and/or the National Marine Fisheries Service (NMFS) prior to project implementation.
During the site designation process, the FWS and the NMFS evaluate potential impacts of ocean
disposal on threatened or endangered species. Their findings are contained in letters which
provide a certification that endangered and threatened species will not be affected. Copies of
letters initiating the consultation process with these agencies are included in Chapter 5.
1.6.2.8 National Historic Preservation Act of 1966 (16 USC Parts 470 et sea.}
The purpose of the National Historic Preservation Act is to preserve and protect historic and pre-
historic resources that may be damaged, destroyed, or made less available by a project Under
this Act, federal agencies are required to identify cultural or historical resources that may be
affected by a project and to coordinate project activities with the State Historic Preservation
Officer (SHPO). EPA is coordinating the proposed activity with the SHPO (see Chapter 5).
1.6.3 Executive Orders
1.6.3.1 Executive Order 11593, Protection and Enhancement of the Cultural Environment
(36 FR 8921. May 15. 1971)
This executive order requires federal agencies to direct their policies, plans, and programs so that
federally-owned sites, structures, and objects of historical, architectural, or archaeological
significance are preserved, restored, and maintained for the inspiration and benefit of the public.
Compliance with this order is coordinated with the SHPO.
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1.6.3.2 Executive Order 12372, Intergovernmental Review of Major Federal Programs
(47 FR 3059. July 16, 1982)
This order requires federal agencies to consult with elected officials of state and local
governments that may be affected directly by a proposed federal development. In providing for
this consultation, existing state procedures must be accommodated to the maximum extent
practicable. For this EIS, the EPA, through the LTMS program, has consulted with the
Resources Agency of California, the California Environmental Protection Agency, and the
appropriate state agencies, boards, and departments of the proposed action (see Chapter 5).
L6.4 State of California
1.6.4.1 California Coastal Act of 1976. Public Resources Code Section 3000 et sea.
This Act establishes the CZMP, which has been approved by the U.S. Department of Commerce.
All federal actions which affect the coastal zone must be determined to be as consistent as
practicable with this plan (see CZMA above).
1.6.4.2 California Environmental Quality Act, June 1986 Public Resources Code Parts
21000-21177
The California Environmental Quality Act (CEQA) establishes requirements similar to those of
NEPA for consideration of environmental impacts and alternatives, and for preparation of an
Environmental Impact Report (EIR) prior to implementation of applicable projects. However,
this proposed action is a federal action involving site designation outside state boundaries and,
therefore, does not fall under the purview of CEQA.
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1.7 Relationship to Previous NEPA Actions or Other Facilities That May Be
Affected by Designation of the Disposal Site
Several NEPA actions in the project area potentially may be affected by disposal of dredged
material at an ODMDS. Because disposal activities would occur over open-ocean water, no
facilities or structures would be affected directly. However, resuspension of dredged material or
disposal plumes from an ODMDS must be considered in terms of cumulative impacts to the
water quality, sediment quality, and the biological environment. These projects are shown in
Figure 1.7-1 and described briefly below.
• Channel Bar ODMDS: This site is designated for disposal of material from
maintenance dredging of the San Francisco main ship channel [40 CFR
section 228.12(b)(22)]. The site is 5.6 kilometers (km) from shore, adjacent
to the ship channel.
• San Francisco Southwest Ocean Outfall Project (SWOOP): The outfall is
located 10.2 km from shore off San Francisco at a depth of 23 m
(37°42.267'N, 122°34.65'W). It is operated by the City and County of San
Francisco, and discharges 24 million gallons per day of primary treated sewage
effluent and stormwater runoff.
• City of Pacifica Outfall: The outfall is located 0.8 km from shore off Pacifica
(37°37.917'N, 122°30.500'W) at a depth of 10 m. It discharges 3.2 million
gallons per day of secondary treated sewage effluent.
• Northern San Mateo County Outfall: The outfall is located 0.8 km from shore
off northern San Mateo County (37°42.800'N, 122°30.833'W) at a depth of
10 m. It discharges 8 million gallons per day of secondary treated sewage
effluent.
The XThannel Bar ODMDS and three ocean outfalls are at least 45-55 nmi from the alternative
sites. Because of this large distance, these activities will not be affected directly by the
designation of an ODMDS at any of the alternative sites (see Section 4.4.1.3, Water Quality
Modeling). The Channel Bar Site, designated to receive dredged material from the entrance
channel to San Francisco Bay, does not receive any dredged material from other parts of the Bay.
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38°N -
37°30'N -
CordeUBank /
National Marine /
Sanctuary t
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf oi The Fdrallonas
National Marine Sanctuary
Precau
Z
-------
Thus, disposal volumes and activities at the Channel Bar ODMDS are independent of the amount
of material that might be discharged at an offshore ODMDS.
Three national marine sanctuaries (GOFNMS, CBNMS, and MBNMS) have been designated in
the region. The GOFNMS was designated in 1981 (46 FR 7936; January 26, 1981). The
boundaries of the GOFNMS extend from Bodega Rock to Rocky Point (near Bolinas) and 19 km
beyond the Farallon Islands. GOFNMS regulations prohibit dredged material disposal within the
Sanctuary boundaries. The CBNMS was designated in 1990 (55 FR 4994; December 4, 1990)
and is located adjacent to and north of the GOFNMS boundary. CBNMS regulations also
prohibit dredged material disposal within the Sanctuary boundaries, as well as discharges outside
the boundary which could enter the Sanctuary and injure a Sanctuary resource (NOAA 1989).
The MBNMS includes areas of the continental shelf from the Gulf of the Farallones to Cambria.
The Final EIS for sanctuary designation states that dredged material disposal at a new ODMDS
within the MBNMS boundaries is prohibited (NOAA 1992). The Final Rule for designation of
the MBNMS was published on September 18, 1992.
Project-specific, dredged material disposal operations are proposed by the Navy under Section
103 of MPRSA within a portion of the historical chemical munitions dumping area (CMDA) that
also corresponds to Alternative Site 5 in this DEIS. A Final EIS (Navy 1990) and Supplemental
EIS (Navy 1992) have been prepared for this proposed action. The Final Supplemental EIS
presently is being prepared by the Navy.
A number of other areas delineated in the study region correspond to submarine operating areas,
vessel traffic lanes, and historical waste disposal sites (Figure 1.7-1). These areas are not
previous NEPA actions or facilities. However, they are legitimate uses of the ocean that may
be affected by ODMDS designation (see Chapter 2). Continued use of these areas or, in the case
of historical waste disposal sites, cumulative environmental impacts associated with these areas
could be affected by the designation of an ODMDS. Potential impacts from ODMDS
designation, including cumulative impacts with other disposal operations, are discussed in detail
in Chapter 4 (Environmental Consequences).
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CHAPTER 2
ALTERNATIVES INCLUDING THE PROPOSED ACTION
This chapter discusses five general alternatives for the disposal of dredged material from San
Francisco Bay and compares three alternative ocean dredged material disposal sites (ODMDS).
Each of the alternative ocean disposal sites is evaluated on the basis of the five general and
eleven specific site-selection criteria listed at 40 CFR sections 228.5 and 228.6(a), respectively
(Table 1.1-1). Disposal alternatives are described in Section 2.1 and evaluated in Section 2.2.
2.1 Description of Alternatives
Five general alternatives for the disposal of dredged material from San Francisco Bay are
available: (1) No-Action; (2) ocean disposal; (3) disposal within the Bay; (4) nonaquatic (i.e.,
land-based) disposal; and (5) reuse or treatment options, such as landfill cover, beach
nourishment, or marsh restoration.
These alternatives are being evaluated as part of the Long-Term Management Strategy (LTMS),
an interagency effort led by a State/Federal partnership consisting of the Environmental
Protection Agency (EPA), the U.S. Army Corps of Engineers (COE), the San Francisco Bay
Regional Water Quality Control Board (SFBRWQCB), and the San Francisco Bay Conservation
and Development Commission (BCDC). It is the intent of the LTMS to provide an array of
disposal options—including ocean, within the Bay, and nonaquatic sites—to accommodate the
volumes and composition of material proposed for dredging over the 50-year planning period
(COE 1992a). The LTMS also will develop general guidelines for evaluating the use of
individual disposal options for specific projects, as well as promote utilization of dredged
material for beneficial uses such as wetlands creation and levee maintenance (COE 1992a).
These options are being developed by the LTMS Ocean Studies Work Group, In-Bay Work
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Group, Nonaquatic/Reuse Work Group, and the Implementation Work Group. Overall
management and policy guidance of these groups is provided by an Executive Committee with
LTMS coordination and technical direction delegated to a Management Committee (Section 5.2).
Because other options will be evaluated by ongoing LTMS efforts concerning disposal within the
Bay, nonaquatic/reuse sites, and implementation, this Environmental Impact Statement (EIS)
evaluates only the ocean disposal and No-Action alternatives. Evaluations of non-ocean disposal
options are scheduled for completion in 1994.
The process of designating an ODMDS begins by establishing the need for an ocean disposal site.
Designation of an ODMDS would not preclude the use of other disposal options or beneficial
uses of dredged material. Land-based disposal evaluations are required under 40 CFR sections
227.14 to 227.16 in EPA's Ocean Dumping Criteria for all Marine Protection, Research and
Sanctuaries Act (MPRSA) Section 103 permits. These evaluations are considered by the COE
and EPA as part of the review of individual applications for use of an ODMDS. If disposal
within the Bay or at a nonaquatic/reuse site is feasible, a decision whether an ODMDS is the best
disposal option will be made during the National Environmental Policy Act (NEPA) and permit
review process according to the existing regulations and other guidelines developed by the
LTMS.
2.1.1 No-Action Alternative
The LTMS mission is to develop long-term options that include an array of potential ocean,
within the Bay, and nonaquatic disposal sites to accommodate the dredged material volumes and
composition projected for the 50-year planning period (COE 1992a). The No-Action Alternative
would preclude ocean disposal except under an MPRSA Section 103 permit Use of an MPRSA
Section 103 interim ODMDS is project-dependent and does not provide a long-term management
option. Therefore, the No-Action Alternative would not fulfill the LTMS goal of providing a
long-term, multi-user ODMDS. In addition, in the absence of a designated ODMDS, or Section
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103 interim ODMDS, other disposal options would be required for dredged material, or planned
dredging programs would have to be delayed until a suitable disposal option is identified.
2.1.2 Ocean Disposal Alternatives
The process of identifying potential alternative ocean disposal sites involves several steps (EPA
1986). Once the need for an ocean site has been established, the next step typically is to define
a zone of siting feasibility (ZSF) which establishes a broad potential area for locating an
ODMDS. The geographic boundary of the ZSF is determined by evaluating operational and
economic considerations and jurisdictional limitations. Within the ZSF, historically used disposal
sites and sensitive and incompatible use areas then are identified from existing information
sources (EPA/COE 1984). Sensitive areas may include marine sanctuaries, breeding, spawning,
nursery, feeding, or passage areas of living resources, and significant natural or cultural features
of historical importance. Incompatible use areas may include shipping lanes, mineral extraction
sites, or geographically limited fisheries or shellfisheries (EPA 1986a). After sensitive or
incompatible use areas have been delineated, the remaining portions of the ZSF then may be
considered as candidate areas for siting an ODMDS. Candidate sites are evaluated further based
on site-specific information, plus other considerations such as disposal management requirements
(EPA/COE 1984). Additionally, the Ocean Dumping Regulations (40 CFR 228.5) require that
"EPA will, wherever feasible, designate ocean dumping sites beyond the edge of the continental
shelf and other such sites that have been historically used."
Potential alternative ocean disposal sites within the LTMS study region were identified from an
initial screening process that considered the following: (1) marine sanctuary boundaries; (2)
navigation lanes; (3) submarine operating areas; (4) areas of hard bottom; and (5) Pioneer
Canyon. Study Areas 1, 2, 3, 4, and 5 were delineated by EPA and members of the LTMS
Management Committee as potential alternative ocean disposal sites that represented a range of
depths and distance from shore and that avoided previously identified incompatible use areas
(EPA 1991).
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EPA prepared an Ocean Studies Plan (OSP; EPA 1991) that summarized existing information on
the environmental conditions of the LTMS study region. The OSP also described methodologies
for obtaining additional information and for conducting studies at Study Areas 2, 3,4, and 5, and
Pioneer Canyon, that were needed to support the site designation process. Although the
background information available prior to these surveys suggested that areas such as Pioneer
Canyon and shelf locations in the vicinity of Study Area 2 might contain potentially unique or
sensitive features or resources which should be avoided for ODMDS designation, the OSP
included sampling at these locations to fill specific data gaps and document the areas'
characteristics for the EIS. EPA-sponsored surveys of Study Areas 2, 3, and 4 and Pioneer
Canyon subsequently were conducted from 1990 to 1992. Study Area 5 was surveyed by EPA
from 1990 to 1992 and by the Navy in 1990 and 1991. Results from these surveys (summarized
in Chapter 3) were used to evaluate further the individual LTMS study areas, and eventually to
select the three alternative sites addressed in this EIS.
Coincidental with the development of the OSP, the COE (1991) prepared a draft final ZSF report
that "...delineate[s] the outer geographical boundaries of operational and economic acceptability
within which further environmental, regulatory and socio-economic analysis is performed to
achieve a site designation." Based on analyses of the benefit-to-cost ratios of ten representative
dredging projects in San Francisco Bay, the COE recommended that the ZSF encompass an area
within 53 nmi (100 km) from the Golden Gate Bridge. The ZSF (Figure 2.1-1) includes areas
beyond the edge of the continental shelf, all of which would be accessible using existing
technology and equipment (COE 1991). All of the LTMS study areas are within the region
defined by the ZSF.
The following sections discuss historically used ODMDSs and the sensitive and incompatible use
areas within which dredged material disposal operations would interfere with other activities,
uses, or resources within the LTMS study region. These uses and their geographical locations
are described below and summarized in Figures 2.1-1 through 2.1-4.
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38°N -
37°30'N -
Transverse Mercator Projection
Scale
0 S 10 15 20
Gulf o! The Farallones
National Marine Sanctuary
_ 200m
SMm '
Alternative
Sites
I Pioneer
VCanyon
Zone of
Siting Feasibility
[ZSF Range]
(53 nmi)
Monterey Bay
National Marine
Sanctuary
-123°30-W
-123°w
-122°30-w
Figure 2.1-1.
Locations of National Marine Sanctuaries, Areas of Special Biological
Significance, Reserves, and Features of Potential Scientific Importance
in the LTMS Study Region.
See Table 2.1-1 for a legend to the numbered circles.
The 50m, 200m, 500m, 1,500m, and 2,500m contours correspond to the 28, 110, 275, 825, and
1,375 fathom contours, respectively.
AK0063
2-5
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Table 2.1-1.
Areas of Special Biological Significance (ASBSs), Reserves, National
Marine Sanctuaries (NMS), and Features of Potential Scientific
Significance Shown in Figure 2.1-1.
1. Point Reyes National Seashore
2. Point Reyes Headlands Reserve
3. Point Reyes Headlands Reserve and ASBS
4. Drakes Estero
5. Estero de Limantour Reserve
6. Double Point ASBS
7. Duxbury Reef Reserve
8. Duxbury Reef Reserve and
Extension ASBS
9. Bolinas Lagoon
10. Cordell Bank NMS
11. Gulf of the Farallones NMS
12. Farallon Islands Game Refuge
13. Farallon National
Wildlife Refuge
14. Farallon Islands ASBS
15. Golden Gate National Recreation Area
16. Montara State Beach
17. James Fitzgerald Marine Reserve and
ASBS
•18. Pillar Point, Half Moon Bay
19. Purisima Creek
20. Lobitos Creek, Tunitas Creek
21. San Gregorio State Beach
22. Pomponio State Beach
23. Pescadero Marsh
24. Pescadero Point
25. Bean Hollow State Beach
26. Pigeon Point
27. Franklin Point
28. Aho Nuevo State Reserve
29. Monterey Bay NMS
Source: KL11991.
AK0012-1W51
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38°N -
37°30'N -
CordeilBank /
National Marine/
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf oi The Farallones
National Marine Sanctuary
200m
Faralton
< Islands
250Qm
Alternative
SiteS
San
Francisco
Bay
V Pioneer
VCanyon
Zone of
Siting Feasibility
[ZSF Range]
(53 nmi
Monterey Bay
National Marine
Sanctuary
-123°30'w
-123°w
Figure 2.1-2. Location of Physiographic Features in the LTMS Study Region.
AK0064
2-7
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38°N -
37°30'N -
CordeltBank /
National Marine /
Sanctuary '
CordeJI Bank /
SOtn (
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf oi The Farallones
National Marine Sanctuary
200m
SOO m\L. Farallon
. Islands
.V ...Sari.
Francisco
250dm
Alternative
Sites
San
Francisco
Bay
Gumd
Seamolinl
Zone of
Siting Feasibility
[ZSF Range]
(53 nmi)
Monterey Bay
National Marine
Sanctuary
-123°30'W
-123°w
-122°30Vv
Figure 2.1-3. Location of Navigation Channels and Precautionary Zones in the LTMS
Study Region.
AK0066
2-8
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38°N -
37°30'N -
Cord* Bank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
Cordett Bank
SOm -
Gulf of The Farallones
National Marine Sanctuary
200m
Farallon
. Islands
250dm
Alternative
Sites
San
Francisco
Bay
I Fiona
VCanyon
Zone of
Siting Feasibility
[ZSF Range]
(53 nmi)
Monterey Bay
National Marine
Sanctuary
-123°30'w
-123°w
-122°30-w
Figure 2.1-4. Location of Submarine Operating Areas in the LTMS Study Region.
AK0066
2-9
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2.1.2.1 Historically Used ODMDSs
The Channel Bar Site (corresponding to LTMS Study Area 1) is the only historically used
ODMDS presently designated for disposal of dredged material (see Section 3.1.1, Historical Use
of the Study Region). This site received final designation (50 CFR 38524; September 23, 1985),
but can be used only for disposal of sandy sediments dredged from the entrance channel to
San Francisco Bay. The Farallon Island or 100-Fathom site was given interim designation by
EPA in 1977. However, this site is now within the Gulf of the Farallones National Marine
Sanctuary (GOFNMS), which was established in 1981 (46 CFR 7936; January 26,1981), and
disposal of dredged material inside the Sanctuary boundary is prohibited except where
necessitated by national defense or in response to an emergency (15 CFR 936.6). Consequently,
the interim designation of the 100-Fathom site was canceled in 1983 (48 CFR 5557;
February 7, 1983). This site has not been used for dredged material disposal since 1978.
Disposal of dredged material from San Francisco Bay has not occurred routinely at any other
ocean site, except for the limited or experimental use of three sites that have not been designated
for further use (Section 3.1.1): the COE experimental 100-fathom site, the Bay Area Rapid
Transit (BART) site, and Site BIB (Chapter 3, Figure 3.1-1). These sites could be considered
historical sites because they have been used previously for dredged material disposal. However,
the COE experimental 100-fathom site is eliminated from further consideration because it is
within the GOFNMS. The BART site is located in close proximity to the Golden Gate, nearshore
resources, and the Monterey Bay National Marine Sanctuary (MBNMS), and was eliminated from
further consideration for these reasons. Site BIB is located within the boundaries of the
MBNMS, and has also been eliminated from consideration as an ODMDS.
The Navy presently is seeking a project-specific (MPRSA Section 103) permit for disposal of 1.6
million yd3 of dredged material at the proposed Navy Ocean Disposal Site (NODS) located within
the former chemical munitions dumping area (CMDA). This site coincides with LTMS
Alternative Site 5. The COE, with EPA concurrence, will decide whether to designate the site
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after outstanding issues regarding site management and monitoring and dredged material
suitability have been resolved. Therefore, depending on the timing and outcome of this process,
the site may or may not be a historically used ocean disposal site at the time of the MPRSA
Section 102 site designation.
2.1.2.2 Sensitive Areas
EPA's ocean site selection criteria [40 CFR section 228.5(b)] require that impacts to sensitive
areas such as sanctuaries, restricted habitats, and areas with high resource values be avoided.
Sensitive areas in the LTMS study region are discussed below.
The ocean adjacent to San Francisco Bay contains several marine sanctuaries, areas of special
biological significance (ASBSs), ecological preserves, and other areas of special scientific
importance (Figure 2.1-1 and Table 2.1-1). The GOFNMS boundaries extend from Bodega Rock
to Rocky Point (Bolinas) and approximately 19 km seaward of the Farallon Islands. Cordell
Bank, located north of the GOFNMS and 30 km west of Point Reyes peninsula, became a
designated national marine sanctuary in 1990 (55 CFR 4994; December 4, 1990). Routine
disposal of dredged material within the boundaries of either sanctuary is prohibited. Therefore,
the areas within these sanctuary boundaries are eliminated from further consideration as an
ODMDS.
A large area of the California coast from Marin County to Cambria (4,024 nmi2) has been
designated as the MBNMS. The Final EIS for sanctuary designation (NOAA 1992) states that
sanctuary regulations will prohibit disposal of dredged material within the boundary, except at
ODMDS(s) existing on the effective date of designation. Following the EIS public comment
period, the National Oceanic and Atmospheric Administration (NOAA) published a Notice of
National Marine Sanctuary Designation and Final Rule in the Federal Register on September 18,
1992 (57 FR 43310). On November 3, 1992, President Bush signed a bill sponsored by
Congressman Leon Panetta authorizing a bypass of Congressional review of the MBNMS
designation and regulations. Therefore, the MBNMS regulations will become effective 30 days
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after NOAA publishes a Federal Register notice of the bypass action. NOAA anticipates this
will occur prior to January 1, 1993. Because the Final Rule will prohibit dredged material
disposal within the MBNMS boundaries, EPA will not designate an ODMDS within the
sanctuary. EPA regulations [40 CFR section 228.10(c)(l)(i)] also describe a 12-mile zone around
sanctuaries in reference to monitoring of disposal sites. However, EPA and NOAA agree that
designation of an ODMDS within this zone is not precluded by EPA or sanctuary regulations,
or by MPRSA (W. Reilly, EPA, letter to Gov. Pete Wilson dated June 22, 1992).
Several ASBSs occur along the coast between the Point Reyes National Seashore and Ano Nuevo
Point, within the GOFNMS and the MBNMS (Figure 2.1-1). These locations represent breeding,
nursery, haul-out, and feeding areas for marine mammals; over-wintering, breeding, roosting, and
migratory passage areas for birds; or geographically limited habitat for large numbers of plant
and animal species, including several threatened and endangered species. The need to protect
these ASBSs is, in part, justification for including these regions in the GOFNMS, the CBNMS,
and the MBNMS. Further, the nearshore zone adjacent to this portion of the coast would not be
appropriate for further considerations of ODMDS siting because of potential shoreward transport
of dredged material and degradation of water quality at the shoreline.
The presence of several hard-bottom features, submarine canyons, or seamounts has been
identified in locations off the continental shelf (e.g., Nybakken et al. 1984; Towill, Inc. 1986;
Parr et al. 1988; SAIC 1992b). Significant hard-bottom features are located at depths of
approximately 900 m near the GOFNMS boundary, on and adjacent to Pioneer Seamount, and
scattered within Pioneer Canyon south of the GOFNMS (Karl 1992). Sparse hard-bottom habitats
also were noted within portions of LTMS Study Areas 3 and 4 (SAIC 1992b) and Study Area
5 (SAIC 1992a). Other areas with potential hard-bottom features are associated with Gumdrop
and Guide Seamounts located to the north and far south of Pioneer Seamount, respectively
(Figure 2.1-2). Previous studies conducted in submarine canyons off southern California and
within Monterey Canyon revealed the presence of rich or unique biological communities (e.g.,
Hartman 1963; Embley et al. 1990). Therefore, significant hard-bottom features, submarine
canyons, and seamounts off San Francisco may represent unique biological habitats or areas of
2-12
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scientific importance. In addition, the difficulty of predicting dredged material dispersion in the
vicinity of seamounts and canyons also makes these areas unlikely to be suitable for an ODMDS.
Nevertheless, because the information previously available for characterizing and evaluating the
potential sensitivities of these features or habitats was sparse, EPA conducted surveys within
Pioneer Canyon (SAIC 1992b,c) to complete the regional characterization.
Information on potentially sensitive areas within the study region was obtained during studies
sponsored by the COE (Nybakken et al. 1984; Towill, Inc. 1986; Stevenson and Parr 1987; Parr
et al. 1988) to evaluate potential ocean disposal sites, the majority of which were located on the
continental shelf (Figure 2.1-5 and Table 2.1-2). These studies were intended to characterize the
physical features (e.g., bathymetry and sediment grain size) and biological habitat (benthic
infauna and demersal fishes). Based on the study results, Stations 1 and 2 and Site B4 were
considered inappropriate locations for an ODMDS due to the presence of hard-bottom features
or rich biological assemblages and fisheries resources (Table 2.1-2). The remaining sites were
ranked by Parr et al. (1988) for potential disposal site suitability based on the density and
diversity of the infaunal and demersal fish assemblages and abundances of Dungeness crabs.
Sites B2, B5, and Dl appeared to be used by sensitive life stages of Dungeness crabs, and Site
1M was located in an area of intensive crab fishing. Site B3 was located close to shore and to
nearshore kelp beds, as well as being within heavily used vessel traffic areas; this site also
contained some hard-bottom habitat. Site Bl was near the GOFNMS boundary, and Site B1A
was located near productive rockfishing reefs. Survey data indicated that Site BIB is removed
from Dungeness crab and rockfish habitat, and that the site supports low infaunal abundances and
diversity. Additionally, historical fish block data for this area suggested that the commercial fish
catch was relatively low. Based on this assessment, Site BIB was considered the most suitable
of the sites evaluated. This site was selected as the preferred alternative site for disposal of
400,000 yd3 of dredged material from the Oakland Inner Harbor Deepening Project. However,
only 18,000 yd3 of dredged material was disposed at Site BIB before the project was halted by
the State court system.
2-13
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38°N -
37°30'N -
CordellBanK /
National Marine /
Sanctuary /
Cordeit Bank /
50m t
Transverse Mercator Projection
Scale
0 5 10 1S 20
Gulf of The Farallones
National Marine Sanctuary
200m
500 m^ Faralton
. Islands
v \\San.
D1 f Francisco
250dm
Alternative
SiteS
San
Francisco
Bay
IPtoneer
iCanyon
Zone of
Siting Feasibility
[ZSF Range]
(53 nmi)
Monterey Bay
National Marine
Sanctuary
-I23°30-w
-123°w
-122°30Vv
Figure 2.1-5. Location of the Ocean Disposal Sites Evaluated by the COE in the Vicinity
of the Gulf of the Farallones.
Refer to Table 2.1-2 for site details.
AK0067
2-14
-------
Table 2.1-2. Potential Ocean Disposal Sites Evaluated by the COE, as Shown in Figure 2.1-5.
Site
Station 1
Station 2
Bl
B2
B3
B4
Center Coordinates
Latitude
37°40.00'N
37°29.00'N
37°31.27'N
37°22.77'N
37°16.10'N
37°30.00'N
Longitude
122°44.00'W
122°57.00'W
122°50.18'W
122°50.18'W
122°31.00'W
123008.50'W
Depth (m>
50
180
80-90
110-140
60-80
900
Sampling Date
March/June, 1983
March/April, 1983;
September, 1983
January-May, 1986;
October, 1986;
April, 1987
January-May, 1986;
October, 1986;
April, 1987
January-May, 1986;
October, 1986
January-May, 1986
Study Conclusions
Productive fishery area for lingcod, flatfish,
and Dungeness crab; designation considered
inappropriate until other alternatives explored.
Highly productive hard-bottom area that
supports rockfish and sablefish fishery;
designation considered inappropriate until
other alternatives explored.
Fish abundances low to high; site may be
important nursery habitat for two fish species.
Supports high numbers of commercially
important fish species and Dungeness crab;
may be particularly important habitat for
brooding crabs.
Includes some hard-bottom habitat and
supports rich fish and benthic assemblages;
also, possible interferences with coastal
shipping routes.
Located in a large submarine canyon;
eliminated from further consideration due to
high-relief rock outcroppings.
Reference
Nybakken et al.
1984
Nybakken et al.
1984
Towill Inc. 1986;
Stevenson and
Parr 1987; Parr
et al. 1988
Towill Inc. 1986;
Stevenson and
Parr 1987; Parr
et al. 1988
Towill Inc. 1986;
Stevenson and
Parr 1987; Parr
et al. 1988
Towill Inc. 1986
to
\ AK0013.W5I
-------
Table 2.1-2.
Continued.
Site
B5
B1A
BIB
1M
Dl
Center Coordinates
Latitude
/37°29.65*N
37°27.00'N
37°29.00'N
37°38.70'N
37°46.83'N
Longitude
122°55.20'W
122°44.50'W
122°48.00'W
122°42.27'W
122°32.66'W
Depth (m)
110-140
80-85
84-88
42-46
18-24
Sampling Date
January-May,
October, 1987,
April, 1987
April, 1987
April/May 1988
April/May, 1988
April/May, 1988
Study Conclusions
Productive rockfish area, possibly due to
presence of mixed hard-bottom habitat, and
supports sensitive life stages of Dungeness
crabs; considered inappropriate for site
designation.
Possible hard substrate downcoast from site;
moderate to high fish abundances; site used as
nursery area by two commercial fish species.
Low to high fish abundances; minor to
moderate use of site as nursery area. Low
crab densities and historically low commercial
fish catch.
Medium to high densities of Dungeness crabs;
located in area of intensive commercial crab
fishery activity.
Historical BART site - 1 nmi from shore and
0.5 nmi south of Entrance Channel; site
contains medium sand-sized sediments
considered incompatible with dredged
materials. Contains high densities of juvenile
crabs.
Reference
Towill Inc. 1986;
Stevenson and
Parr 1987; Parr
et al. 1988
Parr et al. 1988
Parr et al. 1988
Parr et al. 1988
Parr et al. 1988
ON
Sources: Nybakken et al. 1984; Stevenson and Parr 1987; Parr et al. 1988.
AK0013.W51
-------
Although results from these studies indicated significant resource values at many of these
stations, there remained substantial controversy regarding the scope and methodology of the
studies. Therefore, EPA retained some stations from the previous studies in the surveys of
LTMS Study Area 2 to better characterize and document the resources in this area.
2.1.2.3 Incompatible Use Areas
As part of ODMDS designation, incompatible use areas such as regions of heavy commercial or
recreational navigation should be avoided [40 CFR 228.5(a)]. Within the LTMS study region,
incompatible use areas include vessel traffic lanes and submarine operating areas. The effect of
incompatible use areas on selection of the LTMS study areas is discussed below.
The U.S. Coast Guard (USCG) established vessel traffic lanes and a precautionary area within
the Gulf of the Farallones (Figure 2.1-3) to promote safe navigation of marine traffic to and from
ports within San Francisco Bay. The "General Approach to Site Designation Studies for Ocean
Dredged Material Disposal Sites" (EPA/COE 1984) lists navigational lanes as incompatible use
areas. Therefore, areas corresponding to the traffic lanes and the precautionary zone were
eliminated from consideration (Table 1.1-1).
Submarine operating areas Ul, U2, U3, U4, and U5 are used by the U.S. Navy for classified
submarine operations and post-overhaul seatrials (Figure 2.1-4). Portions of area U3 are within
the Cordell Bank National Marine Sanctuary (CBNMS) and the GOFNMS, and the northern
boundary of area U4 is contiguous with the southern boundary of the CMDA and Study Area 5.
The Navy confirmed that it was acceptable for EPA to conduct studies within some of the
submarine operating areas [E. Lukjanowicz (Navy) pers. comm. to S. Clarke (EPA) June 16,
1992], but the Navy also expressed concern that dredged material disposal within areas Ul, U2,
and U5 could jeopardize submarine operations or result in collisions between disposal barges and
submarines or support vessels. Therefore, areas corresponding to submarine operating areas Ul,
U2, and U5 were eliminated from consideration.
2-17
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Based on the location of sensitive and incompatible use areas, and comments received at a
Scoping Meeting held on April 11, 1989, EPA and members of the LTMS Management
Committee selected LTMS Study Areas 1 through 5 (Figure 2.1-1) as potential locations for
siting an ODMDS. The LTMS study areas represent appropriate ranges of depths and distances
from shore within the ZSF and avoid most of the sensitive and incompatible use areas.
Figure 2.1-6 provides a summary overlay of the primary sensitive and incompatible use areas in
the LTMS study region. LTMS Study Area 1 corresponds to the Channel Bar ODMDS, which
is designated for disposal of sandy material from the entrance channel to San Francisco Bay. The
previously used Site BIB is located within LTMS Study Area 2 and the historical CMDA is
within LTMS Study Area 5. Ocean disposal alternatives are described further in Section 2.2.
2.1.3 San Francisco Bay and Nonaquatic Disposal and Reuse Alternatives
The feasibility and environmental consequences of using sites within the Bay, nonaquatic sites,
and reuse options for disposal of dredged material are being investigated under the LTMS
program by the COE, the SFBRWQCB, and the BCDC, with significant input from other LTMS
participants (see Chapter 5). Detailed evaluations of these dredged material disposal options are
beyond the scope of this EIS. However, the following summarizes the present status of these
options.
2.1.3.1 San Francisco Bay Alternatives
Eleven open water (unconfined) disposal sites in the San Francisco Bay region have been used
historically for disposal of sediments dredged from within the Bay. Four of these
sites—Carquinez Straits (SF-9), San Pablo Bay (SF-10), Suisun Bay, and Alcatraz
(SF-11)—presently are used for dredged material disposal (Table 2.1-3). The Carquinez Straits,
San Pablo Bay, and Alcatraz disposal sites are used for most Federal and private maintenance
dredging projects; the Alcatraz site also has been used for new work projects in the Bay. The
Suisun Bay site is used exclusively for material composed of at least 95% sand dredged from the
adjacent Suisun Bay Channel. The sites are located in high current energy areas to promote
2-18
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38°N -
37°30'N -
Cordeil Bank /
National Marine /
Sanctuary
CordeJt Bank /
SOm f
GulfofTheFaralldnas
National Marine Sanctuary
200m
Precautionary
Z^fie
/
250dm
Alternative
SiteS
Farallon
. Islands
\ Fiona
iCanyon
Zone of
Siting Feasibility
[ZSF Range]
(53 nmi)
Disu
Explo
Site #2
Bisused
Exlosives
Monterey Bay
National Marine
Sanctuary
-123°30-w
-123°w
-122°30'w
Figure 2.1-6. Locations of Study Areas 2 Through 5 Within the LTMS Study Region as
Related to Sensitive and Incompatible Use Areas.
AK0068
2-19
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Table 2.1-3. Designated Open Water Dredged Material Disposal Sites in the San Francisco Bay Region.
Site
Alcatraz
San Pablo
Carquinez Straits
Suisun Bay
Location
San Francisco Bay; Central Bay
San Francisco Bay; North Bay
San Francisco Bay; North Bay
Suisun Bay; North Bay
Target Disposal Volumes (yd3)
4 million (annual)
0.3 million (monthly;
May-September)
1.0 million (monthly;
October-April)
0.5 million (monthly or annual)
2.0 million (annual)
3.0 million (annual- wet year)
1.0 million (monthly)
0.2 million (annual-planning
estimate)
Site Use Restrictions
Slurried Bay sediments
Slurried Bay sediments
Slurried Bay sediments
Disposal of sandy sediment from
adjacent shipping channel
to
10
o
Source: COE 1992a; COE 1990a.
AK0014.W51
-------
dispersion and eventual transport of dredged material to the ocean (COE 1990a). The seven other
historical disposal sites in the Bay, typically located within one mile of the respective dredging
sites, have not been used since 1972 (COE 1990a).
The San Pablo and Carquinez Straits sites receive average annual dredged material volumes of
0.2 million yd3 and 1.4 million yd3, respectively (COE 1992a). In accordance with present COE
policy, dredged material discharged at these sites is slurried prior to discharge. The annual
dredged material disposal volume planned for the Suisun Bay disposal site also is 0.2 million yd3
(COE 1990a). The capacities of these sites are not known. The Alcatraz disposal site has
received an average volume of over three million yd3 of dredged material per year since 1972.
Studies conducted at the site in the early 1980s (e.g., SAIC 1987) indicated dispersion of the
discharged sediments was lower than predicted, and accumulation and mounding of dredged
material within the site was significantly limiting the capacity for long-term use. Consequently,
since 1986, the COE has imposed a slurry requirement for material disposed at the site to
promote dispersion and to minimize accumulation (COE 1990a). The present capacity of the
Alcatraz site to accept slurried material is not known because the factors controlling dispersion
are poorly understood (COE 1990a). Periodic removal of a portion of the accumulated materials
from the Alcatraz site may be required in the future.
Other sites within the Bay which are potentially suitable for dredged material disposal were
investigated by Nolte and Associates (1987) and PTI (1989). The capacities and dispersive
characteristics of most of these sites also are not known (COE 1992a). Designation of new sites
within the Bay must comply with the requirements of Section 404(b)(l) of the Clean Water Act
(CWA). The COE, in cooperation with the EPA, is responsible for regulating the use of sites
within the Bay, and the State and Regional Water Quality Control Boards are responsible for
issuing water quality certifications (COE 1992a).
Several resource and regulatory agencies—including the California Department of Fish and Game
(CDFG), National Marine Fisheries Service (NMFS), and the SFBRWQCB-have expressed
concern about: the effects of open water disposal operations on fisheries resources in the Bay;
2-21
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alteration of benthic and shoreline habitats; increased water column turbidity; and remobilization
of chemical contaminants associated with resuspended sediments. In 1990, SFBRWQCB
Resolution No. 89-130 was adopted conditionally by the California State Water Resources
Control Board (Resolution No. 90-37). Resolution 89-130 included: (1) target monthly and
annual disposal volume limits for each of the sites within the Bay; and (2) a requirement for the
COE to demonstrate "...that there are no significant or irreversible impacts occurring from the
disposal of maintenance dredged material in San Francisco Bay." The target limits for the annual
disposal volumes at the San Pablo and Carquinez Straits sites are 0.5 million yd3 and 2.0 million
yd3, respectively (except that the limit for the Carquinez Strait site during wet weather years is
3.0 million yd3). The target annual volume for the Alcatraz site is 4.0 million yd3 (Table 2.1-3).
The resolution also states that the RWQCB will encourage land and ocean disposal alternatives
whenever possible. The measures contained in this resolution are implemented by the RWQCB
through the issuance or denial of waste discharge requirements, water quality certifications under
Section 401 of the CWA, or other orders for individual dredging projects that propose disposal
volumes which exceed the annual or monthly targets.
The Bay Farm Borrow Area (BFBA) is being investigated by the COE as a potential confined
aquatic disposal site. This site is located in the central Bay, immediately west of the northern
portion of Bay Farm Island, and it consists of a "borrow pit" that was excavated in the 1950s for
material used as fill for the Island and for dike construction and maintenance. The site
dimensions are 2,800 m by 1,500 m, with an average potential fill depth of 3 m (i.e., the depth
below the adjacent bottom) and an estimated capacity of 16 million yd3. The environmental
characteristics, including the physical and chemical characteristics of the bottom sediments,
benthic infaunal abundances, fish abundances, and current patterns, and the potential suitability
of the BFBA as a confined open-water disposal site presently are being evaluated.
2.1.3.2 Nonaquatic Disposal and Reuse Alternatives
Existing and potential nonaquatic and reuse sites presently are being evaluated by the LTMS
Nonaquatic/Reuse Work Group as candidate dredged material disposal sites. Of the 65 potential
2-22
-------
sites originally identified, nine sites have been characterized as "highly feasible sites." These
sites and their potential uses are listed in Table 2.1-4. The LTMS selected three of these
sites—Cullinan Ranch, Cargill Salt Div-1 (East), and Cargill Salt Div-1 (West)—for preliminary
engineering feasibility assessments. The assessments are scheduled for completion in June 1994.
The primary factors affecting the feasibility of dredged material disposal at nonaquatic sites
include groundwater quality, distance from the dredging area, site capacity, local resource
concerns, and monitoring requirements (COE 1992a). The use of existing nonaquatic disposal
sites has declined in recent years due to extensive development, exhausted capacity, and
restrictions against filling wetlands (COE 1990a).
Dredged material may have beneficial uses for projects such as marsh restoration, levee
maintenance, beach nourishment, and landfill cover. These alternative disposal options are being
evaluated independently as part of the LTMS process. However, the suitability of dredged
material for use in any project will depend on a variety of engineering, economic, environmental,
and regulatory considerations. For example, key factors affecting the feasibility typically include
site access and capacity, compatibility of the dredged material with construction or engineering
requirements, contaminant levels in dredged material, presence of critical habitat or endangered
species, habitat replacement value, and regulatory requirements of local, state, and federal
governments (COE 1992a). Specific beneficial or reuse options are summarized briefly below.
Several habitat development and marsh restoration projects have been proposed at sites within
the San Francisco Bay area. The six sites/projects ranked as highly feasible by the LTMS
Upland/Reuse Work Group are: (1) Cargill Salt Div-1 (West); (2) Hamilton Antenna Field;
(3) Cullinan Ranch; (4) Sonoma Baylands; (5) Montezuma Wetlands; and (6) Skaggs Island
(Table 2.1-4). The capacities of these proposed projects for dredged material range from
approximately 2.5 to 40 million yd3.
The proposed levee rehabilitation/maintenance projects evaluated as dredged material disposal
options are located in the Sacramento and San Joaquin River delta area. The primary sites and
estimated capacities are: Sherman Island (1.8 million yd3); Twitchell Island (0.4 million yd3);
2-23
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Table 2.1-4. Upland Reuse/Disposal Options Classified as "Highly Feasible" by the
LTMS Nonaquatic/Reuse Work Group.
Candidate
Site
Site Status and Feasibility
Projected Site
Capacity (yd3)*
Additional Remarks
Port
Sonotna-
Marin
Presently used and "highly feasible"
for continued use as rehandling
facility.
0.05 million/yr throughput
(for use at Redwood Sani-
tary Landfill).1'2
0.2 miles from existing barge access
channel.
Leonard
Ranch
Identified as "highly feasible" for
dredged material rehandling project.
LTMS preparing feasibility study to
construct on-site rehandling facility.
COE directed by Congress to study.
Up to 0.95 million/yr
throughput (for possible use
at Redwood Sanitary
Landfill), if entire site
used.1'2
1 mile from existing barge access
channel. Need funding to under-
take. Site owned by Sonoma Land
Trust.
Praxis/
Pacheco
Identified as "highly feasible" for
dredged material confined disposal
and/or rehandling project. LTMS
preparing more detailed feasibility
study.
0.64 million/yr throughput
for rehandling, or 2.5 mil-
lion for confined disposal.1'3
Project constraints due to sewer
easement. No project sponsor.
Privately-owned; site acquisition and
funding required. 3 miles from
existing barge access channel.
Sonoma
Baylands
(330-acre
project)
Identified as "highly feasible" for
dredged material habitat creation pro-
ject. Congressional direction to COE
to undertake has yet to be approved.
2.5 million for habitat
creation.
Need funding to undertake.
0.6 miles from existing barge access
channel.
Montezuma
Wetlands
Identified as "highly feasible" for
dredged material habitat creation,
contained disposal, and/or reprocess-
ing project; proposals pending for
first two uses.
20 million for habitat
creation.
0.1 mile from existing barge access
channel.
Skaggs
Island
(Navy-
owned)
Identified as "highly feasible" for
dredged material confined disposal
and/or habitat creation project; will
be the subject of additional LTMS
research.
14 million for habitat
creation, or 72 million for
confined disposal.3
3-mile pumping distance across salt
ponds. Would require Navy base
closure and funding to undertake.
Cargill Salt
Div. 1 (East
and West)
Identified as "highly feasible" for
dredged material confined disposal,
rehandling, and/or habitat creation
project; LTMS will prepare
conceptual plan.
Up to 3 million/yr through-
put for rehandling, or 14.2
million for confined disposal
(at east site).1'3 40 million
for habitat creation (at west
site).
Site acquisition and funding nec-
essary; site available only if Cargill
cannot find buyer for salt. No pro-
ject sponsor. Adjacent to existing
barge access channel.
Cullinan
Ranch
Identified as "highly feasible" for
dredged material habitat creation pro-
ject. Possible subject of further
LTMS research; FWS conducting
preliminary planning.4
7.2 million for habitat
creation.
Need funding to undertake.
0.5 miles from existing barge access
channel.
Hamilton
AFB:
Antenna
Field
Identified as "highly feasible" for
dredged material habitat creation
project.
2.7 million for habitat
creation.
Public site ownership; COE and
CDFG potential project sponsors.
Need funding to undertake. 3 miles
from existing barge access channel.
"Capacities are preliminary planning estimates.
'Rehandling projection based on assumption that total amount of rehandled material removed annually; subject to change depending upon disposal
site size and specific needs of end-user.
2Redwood will need up to 14 million yd3 of wet material, if landfill expansion permitted; if not permitted, only 1.6 million yd3 of wet material
will be needed by Redwood.
3Confined disposal projection based on assumption that multiple disposal events and an average 40% compaction rate for in-place, dry material
will occur; subject to change depending upon disposal site size.
4Shell Oil Trust will fund initial studies.
Source: LTMS Non-Aquatic/Reuse Work Group, 1992.
AJ0105.W51
2-24
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Jersey Island (1.6 million yd3); Lower Jones Tract/Mitchell Island (1.8 million yd3); Chipps Island
(2.0 million yd3); and Tubbs Island (capacity presently unknown) (COE 1992a). The primary
constraints in using sediments dredged from San Francisco Bay for delta area levees are the
potential effects of adding saline waters (associated with the dredged material) to a freshwater
environment (COE 1992a).
Some of the sediments dredged from San Francisco Bay may be suitable for landfill cover and
construction fill. Nolle and Associates (1987) estimated that 115,000 yd3 per year of dried
(processed) dredged material could be used for construction fill near a given processing site, and
15,300 yd3 per year could be used at sanitary landfill sites. The Redwood Sanitary Landfill near
San Pablo Bay was identified by the LTMS Upland/Reuse Work Group as a landfill which could
use from 140,000 to 440,000 yd3 of dredged material per year. Both Port Sonoma-Marin and
Leonard Ranch sites have been identified as highly feasible sites for re-handling dredged material
intended for Redwood Sanitary Landfill (Table 2.1-4).
Ocean Beach, south of the Golden Gate, has been severely eroded, and California Coastal
Commission staff has suggested that this area may be a candidate site for beach nourishment
(L. Madalon, COE, pers. comm. 1992). However, it is unlikely that the majority of sediments
from any of the planned dredging projects would be appropriate for nourishment of this or other
local beaches because the sediments are expected to consist primarily of fine-grained materials.
These sediments would not be consistent in quality or size with the sands that occur on the
beaches. The use of dredged material for beach nourishment will be evaluated by COE on a
project-specific basis.
As discussed in Chapter 1 of this EIS, designation of an ODMDS does not preclude further
consideration of within the Bay or Nonaquatic/Reuse alternatives for specific projects. The COE
and EPA will evaluate other feasible alternatives on a project-specific basis during the MPRSA
Section 103 permitting process. In addition, the LTMS Implementation Work Group will address
disposal and beneficial reuse options for the San Francisco Bay area.
2-25
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2.2 Discussion of Alternatives
This section presents a discussion of the alternatives that are not being considered for further
analysis (Section 2.2.1), a discussion of how the three proposed ocean disposal site alternatives
comply with EPA's general and specific site selection criteria (Sections 2.2.2 and 2.2.3,
respectively), and a discussion of the preferred alternative (Section 2.2.4). Detailed information
and an evaluation of each candidate disposal site with EPA's general and specific criteria are
presented in Chapter 3, Affected Environment, and Chapter 4, Environmental Consequences.
The LTMS initially included Study Areas 1, 2, 3, 4, and 5 as potential areas within which an
ODMDS might be designated for disposal of San Francisco Bay sediments. However, because
Study Area 1, corresponding to the Channel Bar ODMDS, is only designated for disposal of
sandy material from the San Francisco Bay entrance channel, Study Area 1 was eliminated from
further consideration because the characteristics of fine-grained, dredged material would be
incompatible with restrictions on disposal site sediments. Study Area 2 originally was included
as a candidate location on the continental shelf, and was subjected to considerable study effort
by the COE (KLI 1991) and EPA (SAIC 1992b,c). Nevertheless, based on its location within
the MBNMS, and because dredged material disposal at a new ODMDS within the Sanctuary is
prohibited (NOAA 1992), Study Area 2 also has been eliminated from further consideration as
an ODMDS. Because extensive and valuable studies have already been conducted as part of
EPA's ocean site designation efforts, the environmental characteristics of Study Area 2 are
presented in this EIS to provide a basis for comparison with Study Areas 3, 4, and 5 and
corresponding Alternative Sites 3, 4, and 5 within these areas.
The locations of the three alternative sites correspond to low-energy depositional zones within
each of Study Areas 3, 4, and 5 and contain sediments which are similar in grain size to those
within the Bay (Section 3.2). Disposal in such zones should minimize the dispersion of dredged
material and minimize the area of impact. Alternative Sites 3 and 4 are located along the central
western and southwestern boundaries of Study Areas 3 and 4, respectively. Alternative Site 5
2-26
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is located along the central portion of the western boundary of Study Area 5, and corresponds
to the approximate location of the proposed NODS Site (Navy 1992) (Figure 2.1-1).
The size of the alternative sites was determined from the results of dredged material deposition
(footprint) modeling (Section 4.2.1.4), and corresponds to the area represented by the model-
predicted 10-mm thick deposit of "mostly silt-clay" material (74% clay and 16% silt) after a one-
year dredged material disposal period at Alternative Site 5. The areas of the model-predicted
10-mm thick deposits at Alternative Sites 3 and 4 are relatively smaller than that at Alternative
Site 5. (However, to be conservative, the size and configuration of all the alternative sites were
kept uniform, corresponding to Alternative Site 5, with an oval shape of dimensions of
approximately 3.7 nmi (6.9 km) long and 2.2 nmi (4.1 km) wide.) The site boundaries
completely incorporate the model-predicted 100 mm (10 cm) thick deposit, which is the threshold
above which impacts are expected to be significant (such as smothering of bottom-dwelling
organisms). Deposition over a one-year period, instead of the 50-year project period, was used
as the basis for delineating the site boundaries because natural physical and biological
recolonization processes are expected to offset potential effects due to deposition of dredged
material at rates less than 10 cm per year. Thus, the present site boundaries are intentionally
conservative. Also, because the site boundaries are based on the sediment deposition footprint,
the authorized discharge area at the surface will be smaller than the area of the actual disposal
site to account for dispersion during settling and to allow material to reach the bottom within the
site boundaries.
2.2.7 Alternatives Not Considered for Further Analysis
Study Area 1, Study Area 2, and the No-Action Alternative will not be considered further as
alternatives in this EIS. As noted above, the physical characteristics of the dredged material are
expected to be incompatible with those of the existing sediments within Study Area 1. Further,
Study Area 2 is located entirely within the MBNMS, and designation of a new ODMDS within
Sanctuary boundaries is prohibited (NOAA 1992). Therefore, Study Areas 1 and 2 were
2-27
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considered by the LTMS to be inappropriate for further analysis as potential ODMDSs.
However, limited discussison of Study Area 2 is included in this document to provide a basis for
comparison with Alternative Sites 3, 4, and 5. The LTMS mission is to provide long-term
options, including ocean disposal, to accommodate the dredged material volumes and
compositions anticipated for the 50-year planning period. The No-Action Alternative would
impede the use of ocean disposal as a long-term management option and therefore is an
undesirable alternative.
2.2.2 Compliance of the Alternative Sites and Study Area 2 with General Criteria for
the Selection of Sites
2.2.2.1 General Criterion 40 CFR 228.5(a)
The dumping of materials into the ocean will be permitted only at sites or in areas selected
to minimize the interference of disposal activities with other activities in the marine
environment, particularly avoiding areas of existing fisheries or shell fisheries, and regions
of commercial or recreational navigation.
Alternative Sites 3, 4, and 5 are in water depths greater than 1,600 m, on the lower continental
slope or rise, and are characterized by sparsely distributed fisheries species of potential
commercial value, including marginally targeted commercial fisheries species such as rattails
(Section 3.4). The use of any of the alternative sites would have minimal effects on existing
fisheries or shellfisheries regions, although vessels towing dredged material barges would pass
through sanctuary and fisheries areas. A direct route to Alternative Site 5 (Figure 2.1-1) is of
concern because accidents or problems with barges in the vicinity of the Farallon Islands could
result in inadvertent releases of dredged material with potential impacts to biological
communities. However, a requirement for barges to stay within the recommended navigation
lanes and away from the Islands would minimize potential impacts of transit to all alternative
sites.
2-28
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None of the alternative sites is located within established precautionary zones, navigation lanes,
or submarine operating areas (Section 2.1.2.3). Therefore, commercial shipping traffic heading
south towards or north from San Francisco should not be affected by use of any of the alternative
sites. Dredged material barges transiting directly to Alternative Site 5 would pass along routes
potentially used by boats engaged in such activities as bird watching, whale watching, or sailing
near the Farallon Islands. However, requirements for dredged material barges to stay within the
navigation lanes and away from the Islands would minimize any potential effects.
Because of its location closer to shore and the Golden Gate, the nearshore region including Study
Area 2 represents greater potential access for smaller vessels, as well as larger commercial traffic,
passing south from or north to San Francisco. Therefore, Study Area 2 likely would be
associated with more commercial and recreational boat traffic than Alternative Sites 3, 4, or 5.
2.2.2.2 General Criterion 40 CFR 228.5(b)
Locations and boundaries of the disposal sites will be so chosen that temporary
perturbations in water quality or other environmental conditions during initial mixing
caused by disposal operations anywhere within the site can be expected to be reduced to
normal ambient seawater levels or to undetectable concentrations or effects before reaching
any beach, shoreline, marine sanctuary, or known geographically limited fishery or
shellfishery.
Alternative Sites 3, 4, and 5 are located outside of any sanctuary boundaries. Results of
modeling dispersion of dredged material from the alternative sites (see Sections 4.2 and 4.4)
indicate very low probabilities of suspended particles from the disposal being transported into the
GOFNMS, CBNMS, or MBNMS. Further, predicted dilution rates would reduce the suspended
particle concentrations to within the range of normal, ambient levels near the sanctuary
boundaries. Thus, all sites would result in undetectable effects on water quality parameters such
as turbidity, dissolved oxygen, or trace contaminant concentrations at sanctuary boundaries.
Based on sediment footprint modeling studies for each alternative site (see Sections 4.2 and 4.4),
dredged material would not be deposited in detectable thicknesses within any of the sanctuary
boundaries.
2-29
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Alternative Sites 3, 4, and 5 are located at least 25 nmi from the Farallon Islands and
approximately 60 nmi from any mainland beach or shoreline (Figure 2.1-1). Therefore, dredged
material disposal activities are not likely to cause effects to these resource or amenity areas.
Alternative Sites 3,4, and 5 are not located within or adjacent to a geographically limited fishery
or shellfishery.
Study Area 2 is located entirely within the MBNMS (Figure 2.1-1) and therefore cannot meet this
criterion of avoiding any significant water quality changes within a sanctuary. Also, an important
, fisheries area exists on the continental shelf off San Francisco and encompasses Study Area 2
and the shoreward portion of Study Area 3.
2.2.2.3 General Criterion 40 CFR 228.5(c)
If at any time during or after disposal site evaluation studies, it is determined that existing
disposal sites presently approved on an interim basis for ocean dumping do not meet the
criteria for site selection set forth in Sections 228.5 through 228.6, the use of such sites will
be terminated as soon as suitable alternate disposal sites can be designated.
The MPRSA site selection process is designed to identify a preferred alternative that minimizes
or avoids unacceptable impacts to the physical, biological, and socioeconomic environment.
Evaluation of the continued use of a designated disposal site will be conducted as part of the site
management and monitoring program administered jointly by EPA Region IX and the COE, San
Francisco District (see Section 4.6).
2.2.2.4 General Criterion 40 CFR 228.5(d)
The sizes of ocean disposal sites will be limited in order to localize for identification and
control any immediate adverse impacts and permit the implementation of effective
monitoring and surveillance programs to prevent adverse long-range impacts. The size,
configuration, and location of any disposal site will be determined as a part of the disposal
site evaluation or designation study.
2-30
-------
The sizes and configurations of the three alternative sites are based on the results of footprint and
water quality modeling studies to identify potential areas of significant sediment accumulation
and plume dispersion from dredged material disposal (Sections 4.2 and 4.4). In general, site size
will be limited, yet will encompass modeled regions of detectable sediment deposition, based on
one year of disposal activity. The site locations are chosen to coincide with low-energy
depositional zones, identified by survey results (Section 3.2), where resuspension and dispersion
of the deposited dredged material will be minimized and monitoring of long-term effects will be
facilitated. Water quality modeling results indicate that disposal within any of the alternative
sites would result in only low probabilities of suspended particles being transported into a
sanctuary boundary (Sections 4.2 and 4.4). Evaluation of the continued acceptability of a
designated site will be conducted in accordance with the site management and monitoring plan.
2.2.2.5 General Criterion 40 CFR 228.5(e)
EPA will, wherever feasible, designate ocean dumping sites beyond the edge of the
continental shelf and other such sites that have been historically used.
Alternative Sites 3 and 4 are located on the continental slope, and Alternative Site 5 is located
on the continental rise.
The only study area that has been used extensively for historical disposal operations is Study
Area 5 (which contains Alternative Site 5). From 1951-54, the general Study Area 5 region,
particularly the southeast area, received sealed containers which included mixtures of low-level
radioactive waste from defense-related, commercial, and laboratory activities (Section 3.1).
Additionally, from approximately 1958 to the late 1960s, the northern portion of the Area
received chemical and conventional munitions disposed of by the U.S. Army (Section 3.1). It
is not known how much of this waste material is present within the boundaries of Alternative
Site 5.
2-31
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Historically, no dredged material disposal has occurred at Alternative Site 5. However, the U.S.
Navy presently is seeking a project-specific permit under MPRSA Section 103 for disposal of
approximately 1.6 million cubic yards within the proposed NODS Site, corresponding to the
approximate location of Alternative Site 5 (Navy 1992). Thus, if this project receives approval,
dredged material disposal may have occurred at the site prior to designation of an MPRSA
Section 102 ODMDS.
Study Area 2 is the only study area located on the continental shelf, representing water depths
less than approximately 200 m (Figure 2.1-1). The BIB site, located within Study Area 2, was
used in 1988 for limited dredged material disposal (approximately 18,000 yd3) (Section 3.1).
Although this site could be considered a historically used site, it now lies within the MBNMS.
2.2.3 Comparison of the Alternatives to EPA's 11 Specific Criteria for Site Selection
40 CFR 228.6(a)
Comparisons to the specific criteria are summarized in Table 2.2-1, and support the selection of
the preferred alternative as discussed in Section 2.2.4. Detailed information on the physical,
biological, and socioeconomic environment is presented in Chapters 3 and 4.
2.2.4 Selection of the Preferred Alternative
Alternative Site 5 has been selected by EPA and the LTMS Ocean Studies Work Group as the
preferred alternative. This site was selected for the following reasons:
• Bathymetric and sediment surveys indicate Alternative Site 5 is located in a
depositional area which, because of existing topographic containment features,
is likely to retain dredged material which reaches the sea floor. This is similar
to the containment potential at Alternative Site 3 but should provide greater
containment than at Alternative Site 4;
• No significant impacts to other resources or amenity areas (e.g., marine
sanctuaries) are expected to occur from designation of Alternative Site 5;
2-32
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Table 2.2-1.
Comparison of the Three Alternative Ocean Disposal Sites and Study Area 2 Based on the 11 Specific Criteria
at 40 CFR 228.6(a).
Criteria
Alternative Site 3
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
1. Geographical position,
depth of water, bottom
topography and distance
from coast.
N)
Lower Continental Slope site,
approx. 50 nmi from coast
and 47.12 nmi from
Golden Gate*; 5 nmi H of
Pioneer Canyon, and 5 nmi E
of Pioneer Seamount
(Figure 2.1-2).
Depths range from approx.
1400 to 1900m.
Located in a topographic low
that is bounded to the west
by Pioneer Seamount and to
the east by a moderately
steep slope.
Sediments comprised mostly
of silt-sized sediments; no
known hard-bottom areas
occur within the site.
Lower Continental Slope site,
approx. 50 nmi from coast
and 54.95 nmi from
Golden Gate*; 10 nmi S of
Pioneer Canyon, and 15 nmi
SE of Pioneer Seamount
(Figure 2.1-2).
Depths range from approx.
1900 to 2100m.
Moderately sloping bottom
that is unbounded (as com-
pared to Alternative Site 3).
Sediments comprised mostly
of sand and silt-sized
sediments; no known hard-
bottom areas occur within the
site.
Continental Rise site, approx.
60 nmi from coast and
49.23 nmi from Golden Gate*
(Figure 2.1-2).
Depths range from approx.
2500 to 3000 m.
Same as Alternative Site 4.
Sediments comprised mostly
of fine grained silts and
clays; no known hard-bottom
areas occur within the site.
• Continental Shelf site,
approx. 10-25 nmi fiom
coast and 26 nmi from
Golden Gate (Figure 2.1-2).
Depths range from approx.
70 to 90m.
Gently sloping bottom.
Sediments comprised mostly
oi sands with some silts; no
known hard-bottom areas
occur within the site.
'Assumes barges would be required to stay within westbound traffic lanes (Ogden Beeman 1992).
AK0017.W51
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Table 2.2-1.
Continued.
Criteria
Alternative Site 3
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
2. Location in relation to
breeding, spawning,
nursery, feeding or
passage areas of living
resources in adult or
juvenile stages.
to
Low numbers of fish species
and abundances (as
compared to Study Area 2).
Moderate numbers of
megafaunal invertebrate
species and abundances.
Moderate use by marine
birds and mammals.
Moderate abundances of
midwater fish species
including juvenile rockfishes.
Infauna community very
diverse and abundant.
Located approx. 5 nmi from
Pioneer Canyon and Pioneer
Seamount; both reportedly
characterized by hard-bottom
communities; currents move
away from Canyon.
• Same as Alternative Site 3.
Same as Alternative Site 3.
• Same as Alternative Site 3.
Same as Alternative Site 3.
Low use by marine birds and
mammals (as compared to
Alternative Sites 3 and 5).
• Same as Alternative Site 3.
Same as Alternative Site 3.
Located approx. 10 nmi
South of Pioneer Canyon but
transport of dredged material
would be towards Canyon
based on generally
northward-flowing currents.
High use by marine birds and
mammals (as compared to
Alternative Sites 3 and 4).
High seasonal abundances of
some midwater species
including juvenile rockfishes
(as compared to Alternative
Sites 3 and 4).
Infauna community with
relatively lower diversity and
abundance (as compared to
Alternative Sites 3 and 4).
Located approximately
30 nmi from Pioneer Canyon;
currents move away from
Canyon.
Important fisheries area of
general shelf region.
• Low abundances of
megafaunal invertebrates,
although high abundances of
juvenile Oungeness crabs
have been reported
historically in the vicinity.
« Same as Alternative Site 5.
Same as Alternative Site 5.
Typical shelf community but
very high abundances and
moderate diversity.
AK0017.W51
-------
Table 2.2-1.
Continued.
Criteria
Alternative Site 3
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
3. Location in relation to
beaches and other
amenity areas.
to
Located at least 50 nmi from
coastal resources and
amenity areas (Figure 2.1-1);
therefore unlikely to be of
concern.
Located approx. 10 and 15
nmi from MBNMS and
GOFNMS, respectively, and
30 nmi from the Farallon
Islands. Therefore, limited
concern based on water
quality modeling results
(Section 4.4).
Same as Alternative Site 3.
Located approx. 10 and 30
nmi from MBNMS and
GOFNMS, respectively, and
45 nmi from the Farallon
Islands. Therefore, limited
concern based on water
quality modeling results
(Section 4.4).
Located at least 60 nmi from
coastal resources and
amenity areas (Figure 2.1-1);
therefore unlikely to be of
concern.
Located approx. 10 and 30
nmi from GOFNMS and the
Farallon Islands, respectively.
Therefore, limited concern
based on water quality
modeling results
(Section 4.2).
* Located at (east 15 nmi from
coastal resources and
amenity areas (Figure 2.1-1);
therefore unlikely to be of
concern.
> Located within MBNMS,
adjacent to the GOFNMS,
and approx. 15-30 nmi from
the Farallon Islands,
Primary concern retated to
wtthtn-sanctuary location.
4. Types and quantities of
wastes proposed to be
disposed of, and proposed
methods of release,
including methods of
packing the waste, if any.
Composition of dredged material
is expected to range between
two types: predominantly 'silt-
clay1 (74% clay, 5% silt, 21%
sand) versus "mostly sand1
(76% sand, 21% clay, 3% silt).
Site use over a 50-year period
could total 400 million cubic
yards, with approx. 6 million
cubic yards per year and
between 1,000-6,000 cubic
yards per barge trip. Split-hull
barges towed by ocean-going
tugboats are most likely disposal
method.
Same as Alternative Site 3.
Same as Alternative Site 3.
Not applicable.
AK0017.W51
-------
Table 2.2-1.
Continued.
Criteria
Alternative Site 3
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
5. Feasibility of surveillance
and monitoring.
USCG has surveillance
responsibility; radar not
feasible; ODSS-like system
feasible.
• Same as Alternative Site 3.
• Same as Alternative Site 3.
• USCG has surveillance
responsibility; radar or
OD$S4ike system feasible.
to
u>
0\
Monitoring feasible but more
difficult because of deep
water depths and subsequent
greater dispersion of dredged
material, and limited
knowledge of potential
impacts to deep-water
communities.
Same as Alternative Site 3;
however, Alternative Site 4's
location near Disused
Explosives Sites #1 and #2
may represent some
additional potential for
hazards during monitoring of
bottom conditions.
Monitoring feasible but
possibly the most difficult
because of greater water
depths, generally larger
footprint, limited knowledge
of deep-water communities,
and potential hazards from
historical disposal of
radioactive waste containers
and chemical and
conventional munitions.
Monitoring would be
simplified due to shallow
depths, but material would
be resuspended and
dispersed farther, making
impact assessment more
difficult
6. Dispersal, horizontal,
transport and vertical
mixing characteristics of
the area, including
prevailing current direction
and velocity, if any.
Flows primarily to northwest
in upper 800-900 m, although
periodic reversals in flow
occur. Currents below
1,000 m generally weaker
than near-surface currents.
Near-bottom flows may be
enhanced by tidal influences
and topography. Sediment
resuspension within Site
expected to be minimal.
Similar to Alternative Site 3.
• Similar to Alternative Site 3.
High energy area; frequent
bottom scouring and rapid
dispersal of sediments.
AK0017.W51
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Table 2.2-1.
Continued.
Criteria
Alternative Site 3
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
7. Existence and effects of
current and previous
discharges and dumping
in the area (including
cumulative effects).
No current or previous
disposal activities.
No current or previous
disposal activities.
The site is within approx. 5
nmi of Disused Explosives
Site #2 (Figure 2.1-6);
however, there are no known
effects.
The site adjoins Disused
Explosives Site #2 and is
within approx. 5 nmi of
Disused Explosives Site #1
(Figure 2.1-6); however, there
are no known effects.
No current disposal activities;
however, the Navy has
requested an MPRSA
Section 103 permit for
disposal of up to 1.6 million
cubic yds of dredged
material.
No documented disposal
within the site; however
disposal of radioactive waste
containers was conducted in
the general Study Area
region from 1951-54.
Chemical and conventional
munitions were disposed
from approx. 1958 to late
1960s at the Chemical
Munitions Disposal Area.
Potential environmental
effects are unknown, but
there was no evidence during
recent surveys of residual
contamination. Potentials for
cumulative impacts are
considered unlikely.
No current disposal
activities.
Limited historical dredged
material disposal (18,000
cubic yards) in 1988; this
smalt volume is unlikely to
have caused any significant
effects.
AK0017.W51
-------
Table 2.2-1.
Continued.
Criteria
Alternative Site 3
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
8. Interference with shipping,
fishing, recreation, mineral
extraction, desalination,
fish and shellfish culture,
areas of special scientific
importance and other
legitimate uses of the
ocean.
to
U)
OO
Only slight potential
interference with other uses
of the ocean, including
shipping, fishing, recreation,
and areas of special scientific
importance (such as the
Farallon Islands), is likely.
NMFS has a sablefish study
area within Study Area 3 but
it is shallower than the
alternative site.
Same as Alternative Site 3.
Dredge barge transit could
cause some interference with
recreational and scientific
boat traffic, particularly near
the Farallon Islands. Under
normal conditions, no
interference with areas of
special importance is
expected; however, accidents
resulting in releases of
material near the Farallones
may be a concern. A
requirement for barges to
avoid the Farallones vicinity
could minimize potential
impacts.
Relatively greater
interference (as compared to
other alternative sites} with
shipping, fisheries, and
recreation due to location on
Continental Shelt No
significant interference with
other uses of the ocean is
expected.
AK0017.W51
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Table 2.2-1.
Continued.
Criteria
Alternative Site 3
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
9. Existing water quality and
ecology of the site as
determined by available
data or by trend
assessment or baseline
surveys.
to
Good water quality.
• Same as Alternative Site 3.
Same as Alternative Site 3.
Sediments contain
background levels or low
concentrations of trace metal
and organic contaminants.
Fish community has low (as
compared to Study Area 2)
numbers of species and
abundances (rattails,
thornyhead rockfish,
eelpouts).
Same as Alternative Site 3.
Same as Alternative Site 3.
Good water quality, although
turbidity may be tiigh (as
compared to the alternative
sites) due to proximity to
San Francisco Bay outflow.
Same as Alternative Site 3.
• Same as Alternative Site 3.
Fish community has low (as
compared to Study Area 2)
numbers of species and
abundances (rattails,
eelpouts, finescale codling).
Fish community diverse and
abundant (e.g., flatfishes and
rockfishes).
AK0017.W51
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Table 2.2-1.
Continued.
Criteria
Alternative Site 3.
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
9. Existing water quality and
ecology of the site as
determined by available
data or by trend
assessment or baseline
surveys (continued).
Moderate number of
megafaunal invertebrate
species and abundances
(sea cucumbers, seastars,
brittlestars).
Infaunal invertebrates very
diverse and abundant
(polychaetes, amphipods,
tanaids, isopods).
• Moderate use area by marine
birds and mammals (as
compared to Alternative Site
5 and Study Area 2). '
• Juvenile rockfishes less
abundant seasonally (as
compared to Alternative
Site 5 and Study Area 2.
Same as Alternative Site 3,
Infaunal invertebrates same
as Alternative Site 3, but
fewer amphipods.
• Low use area by marine birds
and mammals (as compared
to Alternative Site 3).
• Same as Alternative Site 3.
• Moderate number of
megafaunal invertebrate
species and abundances
(sea cucumbers, brittlestars,
sea pens).
• Infaunal invertebrates lower
diversity and abundance
(polychaetes, amphipods,
isopods, tanaids) (as
compared to Alternative Sites
3 and 4).
• High use area by marine
birds and mammals (as
compared to Alternative Sites
3 and 4).
• Mid-water organisms,
including juvenile rockfish,
abundant seasonally (as
compared to Alternative
Sites 3 and 4).
Megafaunal invertebrates
sparse.
Infaunal invertebrates very
high abundances and
moderate diversity
(polychaetes. amphipods,
gastropods).
• High use area by marine
birds and mammals (as
compared to Alternative
Sites 3 and 4).
• Juvenile rockfishes abundant
seasonally (as compared to
Alternative Sites 3 and 4).
10. Potentiality for the
development of nuisance
species at the disposal
site.
Unlikely to recruit nuisance
species from dredged material
due to significant differences in
water depth and environment at
the disposal site as compared to
dredging site; no other disposal
site impacts are expected that
would result in nuisance species.
Same as Alternative Site 3.
Same as Alternative Site 3.
Same as Alternative Site 3,
AK0017.W51
-------
Table 2.2-1.
Continued.
Criteria
Alternative Site 3
(Study Area 3)
Alternative Site 4
(Study Area 4)
Alternative Site 5
(Study Area 5)
Study Area 2
11. Existence at or in close
proximity to the site of any
significant natural or
cultural features of
historical importance.
There are no known significant
natural or cultural features.
Same as Alternative Site 3.
Same as Alternative Site 3.
Same as Alternative Site 3.
AK0017.W51
-------
Existing and potential fisheries resources within Alternative Site 5 are minimal
and the site is removed from important fishing grounds located near
Alternative Sites 3 and 4;
Densities and biomass of demersal fish and megafaunal invertebrates are
estimated to be relatively low compared to those at Alternative Sites 3 and 4;
Potential impacts to other organisms (e.g., seabirds, mammals, and midwater
organisms) are expected to be insignificant even though Alternative Site 5
tends to have slightly higher abundances of these organisms;
Waste disposal has occurred historically in the vicinity of the site (and
disposal of dredged material may occur as part of the Navy MPRSA Section
103 project).
2-42
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CHAPTER 3
AFFECTED ENVIRONMENT
This chapter describes ocean disposal site characteristics, and the physical, biological, and
socioeconomic characteristics of the LTMS study areas and alternative sites (Sections 3.1 through
3.4, respectively). This information provides the basis for evaluating the environmental
consequences of the proposed action (Chapter 4) and for evaluating the specific alternatives
(Chapter 2). The information regarding disposal site characteristics also addresses elements from
several of the general and specific ocean disposal selection criteria (Table 1.1-1).
3.1 Ocean Disposal Site Characteristics
This section addresses: historical uses of the LTMS study areas (Section 3.1.1); types and
quantities of materials to be disposed of (Section 3.1.2); existence and effects of current and
previous disposal operations in the study region (Section 3.1.3); and the feasibility of surveillance
and monitoring of alternative sites (Section 3.1.4).
3.1.1 Historical Use of the Study Region (40 CFR 228.5[eJ)
3.1.1.1 Dredged Material Disposal
Routine dredged material disposal operations have not occurred within any of the study areas.
However, limited dredged material disposal activities have occurred at Site B IB located within
Study Area 2 (Figure 3.1-1). Historically, three ocean sites outside of the study areas have
received dredged material from San Francisco Bay. These sites include: (1) the nearshore Bay
Area Rapid Transit (BART) site; (2) the 100-Fathom site; and (3) the COE experimental site
(Figure 3.1-1). The Channel Bar Site is used routinely for disposal of dredged material from the
3-1
-------
Legend
1 B1B Dredged Material Disposal Site
2 BART Dredged Material Disposal Site
3A 100 Fathom Dredged Material Disposal Site Original Location (1975-78)
3B 100 Fathom Site Repositioned Location
4 COE Experimental Dredged Material Disposal Site
5 Channel Bar Ocean Dredged Material Disposal Site
6 Acid Waste Disposal Site
+ Indicates precise disposal site coordinates
* The polygon around sites 8-10 defines the disposal area for radioactive waste (Joseph 1957).
7 Cannery Waste Disposal Site
8 Rad. Waste Site A*
9 Rad. Waste Site B'
10 Rad. Waste Site C'
11 Chemical Munitions Dumping Area
12 Disused Explosives Site #1
13 Disused Explosives Site #2
38°N -
37°30'N -
Transverse Mercator Projection
Scale
0 5 10 15 20
Alternativ
Gumdnfc Q Site 3
Sea
-123°30-w
-123°w
Figure 3.1-1. Locations of Previously Used Ocean Waste Disposal Sites Within the
LTMS Study Region.
The 50m, 200m, 500m, 1,500m, and 2,500m contours correspond to the 28,110,275,825, and
1,375 fathom contours, respectively.
Sources: ffiC 1973; EPA 1975; Dyer 1976; NOAA 1980; MMS 1986; Delgado and Haller 1989;
Colombo and Kendig 1990.
AK0069
3-2
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entrance to San Francisco Bay, but because of differences in grain size is not designated for
disposal of sediments from within the Bay. The historical uses of these sites for dredged material
disposal are summarized in Table 3.1-1.
The BIB site, located within Study Area 2, was used between May 12 through 16, 1988 for
disposal of 18,000 yd3 (six hopper barge loads) of sediments from the Port of Oakland Harbor
Deepening Project. Disposal operations at this site were enjoined due to a lawsuit and a State
Court injunction (COE 1989). Additionally, the BIB site is located within the boundaries of the
Monterey Bay National Marine Sanctuary (MBNMS).
The BART site received dredged material, primarily mud-sized sediments, generated during 1966
and 1967 from construction of the Trans-Bay Tube. The site was located inshore from the
Channel Bar Site and 0.9-5.6 km from shore. The quantities of sediments generated from this
project were estimated to be 2.3 million yd3 (Ebert and Cordier 1966). However, the site also
is located near the boundaries of the MBNMS.
The 100-Fathom site was used in 1975 for disposal of an unspecified volume of material from
Oakland Harbor that was considered too contaminated for disposal within the Bay (COE 1989).
An additional 20,000 yd3 and 60,000 yd3 of muds from Oakland Inner and Outer Harbors were
reportedly discharged at this site in 1977 and 1978, respectively (EPA 1982). The site was then
moved five kilometers closer to shore to allow radar surveillance of the disposal operations.
However, there is no record that the new site was ever used for dredged material disposal. The
site was canceled in 1983 upon establishment of the GOFNMS (48 FR 5558, February 7, 1983).
The COE experimental site was located approximately 20 km northwest of the 100-Fathom site.
The experimental site was used in 1974 for a test disposal of 4,000 yd3 of muddy sediment from
San Francisco Bay (COE 1975). The purpose of the test was to provide a qualitative description
of the general dispersion of dredged material disposed at the continental shelf break. Post-
disposal monitoring determined the amount of dredged material successfully placed at the site.
This new location was selected to avoid interactions with previous disposal operations at the
3-3
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Table 3.1-1. Summary of Dredged Material Disposal Site Locations and Disposal Activities
Within the LTMS Study Region.
SITE
NAME
Channel Bar
Site1*
BART Site3
100 Fathom
Original
Location1'4
100 Fathom
Repositioned
Location4
COE Test
Site5
B1B4
DEPTH (m)
18.3
20.1-25.6 ~
183
183
183
69.5-87.8
DATE&
DURATION
OF USE
Maintenance Work
(1959-present)
New Projects
(1972-1976)
Total Maintenance
(1976-present)
"1966-1967
1975
1977
1978
unknown
1974
1988
ESTIMATED
VOLUME
DISPOSED
600,000 yd3/yr
8,800,000 yd3
9,079,533 yd3
2,300,000 yd3
unknown
20,000 yd3
60,000 yd3
unknown
4,000 yd3
18,000 yd3
I
LATITUDE,
LONGITUDE
37°45'N, 122°36'W
37°46.5'N, 122°32.5'W
37°32'N, 122°59'W
37°31'N, 122°57'W
37°41'N, 123°7.5'W
37°29'N, 122°48'W
Sources: 1 EPA 1982
2 T. Bruch (COE), pers. comm. 1992
3EbertandCordier1966
4 COE 1989
5 COE 1975
AKOOlS.wSl
3-4
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100-Fathom site that could compromise test results. Results from the post-disposal survey are
described in COE (1975).
The Channel Bar Site has been used since 1959 for maintenance dredged material from the main
San Francisco shipping channel. The original site was located 0.5 nmi south of the main ship
channel (EPA 1982). In 1972, the site was moved from its original location to a site 1.0 nmi
south of the main ship channel to reduce the possibility that discharged sediments could be
transported back into the channel. Present channel maintenance programs generate approximately
900,000 cubic yards (yd3) of dredged material per year which are disposed of at this site (T.
Wakeman, COE, pers. comm. 1992). Estimated maintenance volumes (272,300 yd3) from fiscal
year 1991 were lower than anticipated due to drought conditions (T. Bruch, COE, pers. comm.
1992). In addition to maintenance dredging volumes, an estimated 8.8 million yd3 from Phase
I of the J.F. Baldwin Ship Channel project (D. Myers, COE, pers. comm. 1992) also were placed
at the site between 1972 and 1976 (EPA 1982).
The general site selection criterion at 40 CFR 228.5(c) specifies that "EPA will, wherever
feasible, designate ocean dumping sites ... that have been used historically." With the exception
of the Channel Bar Site, historical use of the other dredged material sites was episodic, and none
of them received final designation for continued disposal use for dredged material from San
Francisco Bay. The Channel Bar Site is suitable for sandy material only, the BART site and the
BIB site are within the boundaries of the MBNMS, and both of the COE experimental sites and
the 100-Fathom site are within the GOFNMS. Therefore, none of the five historically used
dredged material disposal sites in the LTMS study region remain under consideration as a
potential alternative for designation as a permanent site for disposal of dredged material from San
Francisco Bay. In recent years, due in part to the absence of an acceptable ocean disposal site,
most dredged material disposal has occurred at sites within San Francisco Bay.
3-5
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3.1.1.2 Other Waste Disposal
Other waste disposal operations have occurred since 1946 at several sites within the Gulf of the
Farallones. However, it is difficult to identify and characterize all of the waste materials and the
extent of the disposal operations because of:
• Lack of regulations at the time of some disposal events;
• Involvement of numerous agencies and organizations in some disposal
operations;
• Generally poor record-keeping for many of these activities;
• Security classification of military operations; and
• Problems in monitoring the exact location of some disposal activities.
The types of waste materials disposed of in the vicinity of the Gulf of the Farallones include the
following (IEC 1973):
Acid waste
Cannery waste
Low-level radioactive waste
Conventional and chemical munitions
Refinery waste
Vessels and dry dock materials.
These historical waste disposal operations are summarized in Table 3.1-2 and are described
below. Estimated locations of disposal site areas are shown in Figure 3.1-1. Anecdotal
information (Anon. 1980) suggests that some waste disposal occurred outside of intended sites
due to operational problems (e.g., bad weather) or indiscriminate disposal practices. These
historical waste disposal operations, including the presence of residual low-level radioactive
wastes, chemical munitions, and vessel/dry dock sections within the vicinity of the LTMS study
3-6
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Table 3.1-2. Summary of Waste Disposal in the LTMS Study Region.
Waste
Category
Acid waste1
Cannery waste1
Radioactive waste1'2
Munitions1
Dredged material3
Refinery waste1
Vessels and drydock
materials4
Responsible
Agency/Company
USSC
OSC
AEC
USN
COE
Standard Oil,
Shell Oil
See Table 3.1 -5
Period
of
Activity
1948-1971
1961 • 1972
1946 - 1965
1958 - 1969
1976 - Present
1966-1972
1951-1987
Estimated
Annual
Quantity
10M gal
22,000 tons
varied
varied
900,000 yd3
>45Mgal
varied
Estimated
Total
240M gal
246,000 tons
47,500 containers
746 tons
9,079,533 yd3
315M gal
unknown
Latitude, Longitude
37°38'N, 122°40'W
37°39'N, 122° 50'W
See Table 3.1 -3
See Table 3.1 -4
See Table 3.1-1
Three generalized
locations: approximately
5 miles offshore; 1-3 miles
west of the Gulf of the
Farallones;and50-100
miles from shore.
See Table 3.1 -5
USSC
OSC
AEC
USN
COE
United States Steel Company
Oakland Scavenger Company
Atomic Energy Commission
United States Navy
United States Army Corps of
Engineers
Sources: 'IEC1973
2EPA1975, Dyer 1976
3T. Wakeman, T. Bruch, COE, pers. comm. 1992
4P. Cotter, EPA, pers. comm. 1991
AK0019.W51
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areas, represent a possibility for cumulative environmental effects in combination with proposed
dredged material disposal operations.
3.1.1.3 Acid Waste
Between 1948 and 1971, the United States Steel Corporation (USSC) annually discharged
approximately 10 million gallons of steel pickling waste acids (hydrochloric and sulfuric acids)
in an area located approximately 22.5 km southwest of the Golden Gate Bridge, 14.5 km
offshore, at a water depth of approximately 40 m (IEC 1973). Exact coordinates for the disposal
area are unknown due to erroneous documentation of these disposal activities. However, the site
coordinates have been estimated based on reported distances from the Golden Gate Bridge and
from shore (IEC 1973) (Table 3.1-2).
3.1.1.4 Cannery Wastes
Cannery wastes generated by six East Bay fruit and vegetable canneries were disposed of 32.2
km offshore of San Francisco at depths of approximately 80 m. These wastes consisted of solid
residuals (i.e., fruit and vegetable pulp) from canning processes. Estimated weights of 22,000
tons per year were discharged from 1961 to 1972, at which time concerns over increased costs,
monitoring requirements, and environmental issues led to termination of further disposal activities
(IEC 1973).
3.1.1.5 Radioactive Waste
Disposal of low-level radioactive waste materials off the coast of San Francisco occurred between
1946 and 1965. Waste materials originated from several agencies and organizations including:
Nuclear Engineering Company; Ocean Transport Company; Chevron Research; U.S. Naval
Radiation Development Laboratory; Atomic Energy Commission; University of California
Radiation Laboratory at Berkeley; and Lawrence Livermore Radiation Laboratory (IEC 1974;
U.S. Army 1987; Colombo and Kendig 1990). Waste disposal operations were performed by the
3-8
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U.S. Navy until 1959. After 1959, disposal was conducted by private disposal companies under
a license from the Atomic Energy Commission (Colombo and Kendig 1990).
At least three different radioactive waste disposal site locations have been identified. The
reported site coordinates and quantities of wastes are listed in Table 3.1-3. Exact coordinates of
the actual disposal events are unknown; Joseph (1957) suggested that the disposal area can be
defined as an irregular polygon bounded by the coordinates 37° 26'N to 37° 43'N and 122° 48'W
to 123° 25'W, representing an area exceeding 650 square kilometers (Figure 3.1-1).
Radioactive Waste Site A was used briefly in 1946 for disposal of three barge-loads (an
estimated 150 containers) of material. This site was occupied because the orders supplied to the
disposal vessel operators contained a typographical error (IEC 1973). Radioactive Waste Site B
was used between late 1946 and 1951 and from 1954 to 1965. Radioactive Waste Site C was
used between 1951 and 1954. The majority of the wastes (approximately 44,000 containers) was
discharged at Site B. The reason(s) for switching to Site C is unknown, although the concurrent
use of Site B for the disposal of chemical munitions waste and the greater distance from shore
probably were contributing factors (Colombo and Kendig 1990). Isolated disposal of low-level
radioactive wastes also may have occurred closer to shore, due primarily to inclement weather
(IEC 1974). Ocean disposal of radioactive wastes was discontinued around 1965 when land
disposal sites were licensed to receive the wastes. In 1970, the U.S. terminated all ocean disposal
of radioactive waste materials (EPA 1992a).
It is not possible to determine accurately the amounts of low-level radioactive wastes disposed
of by these operations because the characteristics of the waste materials and associated
radioactivity were poorly documented. Nevertheless, the total quantity of radioactive waste
materials disposed of at these sites was estimated at 44,500 to 47,500 containers. The wastes
represented a mix of liquid and solid materials, with a wide variety of chemical and physical
properties, generated from defense-related, commercial, and medical laboratory activities. The
low-level solid wastes included contaminated laboratory equipment and supplies, clothing, rubber
gloves, shoes, animal bones, and grease (U.S. Army 1987). Liquid wastes included evaporator
3-9
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Table 3.1-3. Radioactive Waste Disposal Sites in the Gulf of the Farallones.
SITE
Rad. Waste Site A
Rad. Waste Site B
Rad. Waste Site C
DEPTH (m)
90
1,800
900
NO. OF WASTE
CONTAINERS
150
44,000
3,600
DURATION
OF USE
1946
1946-51,
1954-65
1951-54
LATITUDE,
LONGITUDE
37° 38'N, 122° 58'W
37° 37'N, 123° 18'W
37° 39'N, 123° 09'W
Source: EPA 1975, Dyer 1976
AK0020.W51
3-10
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concentrates, solvents, and aqueous solutions (Colombo and Kendig 1990). The wastes contained
an estimated total activity of 14,500 curies, primarily associated with thorium, uranium,
transuranic and other activation-produced radionuclides, and mixed fission products with
half-lives greater than one year (Colombo and Kendig 1990).
The radioactive waste materials were packaged prior to disposal, typically by "encapsulation in
concrete" within 55-gallon (210 liter) drums or in large (1.5x2x2.5 m), steel-reinforced, concrete
"vaults." Beginning in 1951-1952, the waste containers incorporated a wire-rope or steel bar
lifting eye. The ends of the wire rope or steel bar were encased in the concrete end caps, and
the exposed portions were shaped into an eye or loop that could be used for lifting and handling
the drums. This packaging method was useful for distinguishing and dating individual waste
containers during subsequent site surveys. Reports from the post-disposal surveys at these
disposal sites (e.g., IEC 1974; EPA 1975; Dyer 1976; Colombo and Kendig 1990) and the
testimony of recreational divers, who encountered a package in relatively shallow waters (60 to
165 feet) near the Farallon Islands (Anon. 1980) indicate that the condition of the drums and
vaults varied. Some containers were intact, whereas others had imploded, ruptured, or split.
Thus, presumably some radioactive waste materials were not completely encapsulated because
the packaging was compromised.
3.1.1.6 Chemical and Conventional Munitions Waste
Although there are numerous munitions disposal sites surrounding the Farallon Islands and in the
Gulf of the Farallones, most aspects of the military's disposal operations remain classified. The
U.S. Army has discharged both chemical and conventional munitions at offshore sites since the
late 1950s (Table 3.1-4). From 1958 through 1969, the Army and Navy occupied several ocean
sites off San Francisco for the purpose of munitions disposal (U.S. Army 1987). One of the sites
used for waste munitions was near radioactive waste disposal Site B and within the present Study
Area 5. Munitions waste discharges were made at this site through 1968 and 1969, usually by
towing barges of one-ton containers and unloading the containers overboard. Two other
munitions sites described as containing both explosive and toxic chemical ammunitions (MMS
3-11
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Table 3.1-4. Summary of Munitions Discharges in the LTMS Study Region.
Operation
S.S. WILLIAM
RALSTON1
SEA LION1'2
(barge)
S.S. JOHN F.
SHAFROTH3
Chemical Munitions
Dumping Area
(CMDA)4
Explosives4
Site #1
Explosives5
Site #2
Year
1958
1958
1964
1968-69
Nl
Nl
Cargo
M70 bombs (mustard)
Containers (lewisite)
M47 bombs (mustard)
Containers (lewisite)
Containers (mustard)
Projectiles (mustard)
40 mm ammunition
cartridges
Unspecified bombs
Torpedo warheads
Unspecified mines
Unspecified projectiles
Fuses, detonators
Polaris boosters
Contaminated
"cake-mix"
Conventional munitions
Explosive and toxic
chemical ammunition
Explosive and toxic
chemical ammunition
Total
Cargo
301 ,000
1,497
6
335
11
2
30,000 Ib
510 tons5
_
—
Latitude,
Longitude
37°40'N, 125°00'W
37°40'N, 125°00'W
37°40'N, 123°25'W
37°41'N, 123°25'W
37°10'N, 123°03'W
37°10'N, 123°23'W
(-) = Unknown quantity
Nl = No information
Sources:
1 U.S. Army 1988
2 U.S. Army 1987
3 EPA 1971
4 NOAA Chart No. 18680 1984
5
U.S. Navy 1992
AK0021.W51
3-12
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1986) are located to the east and west of Study Area 4 (Figure 3.1-1). No additional information
about these sites was available.
In 1958, the Army loaded 8,000 tons of aged mustard and lewisite chemical agents aboard the
S.S. WILLIAM RALSTON, which then was towed to a site 190 km off San Francisco and
scuttled at a depth of about 6,500 m. Five years later, the Army initiated the "CHASE" (Cut
Holes And Sink 'Em) program, similar to the earlier sinking of the RALSTON. The CHASE
program used obsolete World War II cargo ships to dispose of large amounts of old munitions
at offshore sites. The ships were loaded with munitions, towed offshore, then sunk at deepwater
sites (EPA 1971). Chemical weapons were disposed of during only four of the twelve CHASE
operations, and none of the vessels were scuttled at any of the Gulf of the Farallones munitions
disposal sites. However, the S.S. JOHN F. SHAFROTH, containing approximately 236 tons of
explosives and ammunition, was scuttled approximately 30 km west of the Farallon Islands,
within the boundaries of Study Area 5.
3.1.1.7 Refinery Waste
Standard Oil Company discharged approximately 45 million gallons of refinery waste annually
from 1966 to 1972 in the vicinity of the Farallon Islands (EEC 1973). Specific information on
the chemical composition of the waste is not available, although it is likely that it consisted of
solvents, petroleum by-products, and residual petroleum fractions. Similarly, specific coordinates
for the waste disposal site were not identified. The "site" initially was listed as "at least five
miles offshore" (IEC 1973), but then was relocated in 1970 to an area one to three miles beyond
(i.e., to the west of) the Gulf of the Farallones. Refinery wastes also were discharged by Shell
Oil Company until 1971, although no information on annual discharge volumes or disposal
frequency is available. The discharge site was described as an area approximately 81 to 161 km
offshore from San Francisco (IEC 1973).
3-13
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3.1.1.8 Vessel and Dry Dock Sections
From 1951 to 1987, several damaged or derelict vessels and dry dock sections were disposed of
in the LTMS study region. A summary of these disposal operations is presented in Table 3.1-5.
Discarded items consisted primarily of metal or wooden hulls and associated equipment of the
vessels and dry dock sections. As required by EPA Ocean Dumping Regulations issued in 1977
(40 CFR 229.3), the fuel and lube tanks, pipes, pumps, and bilges were emptied and flushed and
the other equipment which potentially was capable of resurfacing was removed prior to sinking.
Therefore, the environmental consequences of the majority of these vessel disposal operations
are expected to be minimal.
In contrast, sinkings of the USS INDEPENDENCE and T/V PUERTO RICAN introduced
potentially hazardous materials to the ocean environment. The hull of the USS
INDEPENDENCE was characterized as a highly radioactive hulk after serving as a target vessel
for the Bikini Atoll atomic bomb testing in 1946 (U.S. Navy 1968). The vessel was sunk in
1951 during further weapons testing at an unspecified location off the coast of California (U.S.
Navy 1968). Recent side-scan sonar investigations in the Gulf of the Farallones have identified
a structure believed to be the USS INDEPENDENCE at 37° 28.4'N, 123° 7.6'W (north of Study
Area 3 and southeast of Study Area 5); positive verification has not yet been made (Karl 1992).
The extent of any potential environmental impacts associated with the sinking of the USS
INDEPENDENCE is unknown.
The T/V PUERTO RICAN was transporting 91,984 barrels of lubrication oil and 8,500 barrels
of bunker fuel when an explosion and fire damaged the vessel approximately 13 km off the
Golden Gate in October 1984. The disabled vessel was towed seaward to minimize potential
impacts from leaking fuels to sensitive biological habitats within the GOFNMS. However, the
vessel later broke into two sections, and the stern section, containing 8,500 barrels of oil, sank
at a location approximately 25 km due south of South Farallon Island in a depth of approximately
450 m. The remains have been surveyed using side-scan sonar; and, as of 1989, oil continued
to leak slowly from the vessel (Delgado and Haller 1989). Assessments of the environmental
3-14
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Table 3.1-5. Summary of Vessel and Dry Dock Disposal in the Vicinity of the Gulf of the Farallones.
Date
1951
1980
1981
1981
1984
1985
1987
Vessel/Dry Dock Origin
and Responsible
Agency/Co mpany
USS INDEPENDENCE; U.S. Navy.1
4 tugboats/towing vessels (MA/ SEA
KING, MA/ SEA PRINCE, MA/ SEA
ROBIN, MA/ SEA CLOUD); Crowley
Maritime Corporation.3
AGGATU; Crowley Maritime
Corporation.3
MA/ ISLANDER; U.S. Coast Guard.3
TA/ PUERTO RICAN; U.S. Coast
Guard/Carter and Desmares, Inc.3
YFD-19; Todd Shipyards
Corporation.3
LADY ELEANOR; Valley Engineers.3
Location
37°28.4'N; 123°7.6'W (unconfirmed
side scan sonar coordinates2).
37°31.0'N; 122°52.0'W (approximately
12.5 miles SE of the Southeast
Farallon Light, in approximately 94 m).
37°31.0'N; 122°52.0'W (same location
as the site used for disposal of 4
tugboats in 1 980).
37°30'N; 122°52.0'W
37°30.6'N; 123°00.7'W
Five sections sunk within area:
37°34.9' - 37°37'N;
123°16.0' - 123°18'W.
37°23.5'N; 122°53.1'W
Comments
Aircraft carrier whose hull was characterized as highly
contaminated from radiation exposures during weapons
testing; sunk during further weapons tests.
Four identical hulls (127* x 29'); vessels taken out of service.
Rail barge (206' x 99') damaged in "casualty"; the hull was
split into 2 sections.
A vessel in immediate danger of sinking at the San Francisco
Coast Guard Base, thus posing a threat to navigation.
An oil and chemical carrier damaged by an explosion and fire
while transporting lubrication oil and bunker oil. The stern
section containing bunker oil sank in 450 m.
Floating dry dock disposed as 77' x 1 44' sections; weighted
with 600 tons of concrete and flooded at locations off the shelf
(1,600m).
Pontoon construction platform with crane (120' x 101' x 100');
scuttled/emergency disposal after capsizing off Half Moon Bay.
u>
Sources: 1 U.S. Navy 1968
2Karl 1992
3P. Cotter, EPA, pers. comm. 1991
AK0022.W51
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impacts associated with the oil spill were prepared by Herz and Kopec (1985), Robilliard (1985),
PRBO (1985), and James Dobbins Associates, Inc. (1986).
3.1.1.9 Summary of Historical Disposal in Relation to the LTMS Study Areas
According to site selection general criteria, EPA will designate ocean dumping sites that have
been used historically. A summary of historically used disposal sites indicates that limited
dredged material disposal has occurred within Study Area 2 (BIB site), and radioactive and
chemical munitions wastes were disposed of in Study Area 5. Study Area 4 lies between two
sites previously designated for explosives disposal (Figure 3.1-1); disposal of dredged material
within the explosives sites is not desirable. Historically used dredged material disposal sites such
as the BIB, COE experimental, and 100-Fathom sites lie within designated National Marine
Sanctuary boundaries and therefore cannot be considered for future disposal activities. Similarly,
the Channel Bar Site (Study Area 1) is suitable for disposal of sandy materials only, and is not
under consideration as an alternative site. Radioactive Waste Sites A, B, and C lie within the
boundaries of the GOFNMS.
3.7.2 Types and Quantities of Wastes Proposed To Be Disposed of (40 CFR
228.6[a][4J)
The proposed ODMDS will be used for disposal of acceptable sediments from projects in the San
Francisco Bay area, including maintenance dredging and new construction projects. Presently
planned projects are listed in Table 1.2-1. Site use is expected to extend for fifty years,
beginning in 1994; the projected 50-year dredging volume would total 400 million yards3 (COE
1992a). The COE (1991) estimated that six million yards3 per year could be disposed of at the
ODMDS. However, the specific volumes will depend on the characteristics of the dredged
materials (evaluated on a project-specific basis), potential disposal restrictions in the site
management plan, and the range of alternative disposal options developed by the LTMS (see
Chapter 2).
3-16
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The physical and chemical characteristics of the dredged materials planned for ocean disposal are
expected to vary considerably depending on the locations of the dredging operations. The
possible range in grain-size characteristics of the dredged material is expected to be broad, and
specific grain sizes will vary on a project/site-specific basis (Tetra Tech 1992). However, the
most prevalent sediment composites planned for disposal are expected to range between two grain
size classes: "mostly sand" (76% sand, 21% clay, and 3% silt) and "silt-clay" (74% silt, 5% clay,
and 21% sand) (Tetra Tech 1992). Dredged material will not be packaged prior to disposal.
The COE expects that an ODMDS could be used throughout the year, except when wave heights
exceed 3 meters and wave periods are 9 seconds or less (approximately 10% of the time,
typically from February through May; Tetra Tech 1987). However, seasonal restrictions on
dredging activities imposed by biological events such as migration, spawning, and nesting
activities may also affect the scheduling of ODMDS use. For example, the California
Department of Fish and Game (CDFG) recommends that dredging activities within the Bay be
restricted during peak herring spawning periods (December 1 to March 1) (J. Turner, CDFG,
pers. comm. 1991). In addition, to ensure high survivorship of Dungeness crab juveniles that
utilize the Bay as a nursery ground, CDFG recommends that suction dredging in parts of north
San Francisco and San Pablo Bays be prohibited from May 1 to August 1. Mitigation of
potential impacts from individual projects will be specified in permit conditions. Specific goals
and objectives of the site management and monitoring plan will be published in the FEIS. The
complete site management and monitoring plan will be prepared in conjunction with, and
referenced in, the Final Rule and Coastal Consistency Determination for the site.
3.1.3 Existence and Effects of Current and Previous Discharge and Dumping in the
Area (40 CFR 228.6[a][7J)
As discussed in Section 3.1.1, four locations have been used previously for ocean disposal of
sediments from San Francisco Bay. However, use of these ocean sites for dredged material
3-17
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disposal has been intermittent, and the disposal volumes have been relatively small (except for
the BART site).
The nature and extent of post-disposal effects at these locations are unknown because no
systematic baseline and post-disposal studies have been performed. A brief biological survey of
an area adjacent to the BART site was conducted prior to disposal of dredged material from the
BART construction project (Ebert and Cordier 1966); however, no post-disposal study was
conducted. A series of baseline biological and sediment surveys, and a one-year current meter
study were initiated at the BIB site before the disposal of Oakland Harbor dredged material (KLI
1991). However, no post-disposal effects studies were conducted at this site other than a
continuation of the current meter study. With the exception of a brief qualitative study of the
COE experimental site following a small test discharge of approximately 4,000 yd3 of dredged
material (COE 1975), no studies of the environmental impacts of dredged material disposal have
been conducted at any of the offshore sites.
Similarly, studies of the environmental impacts from disposal of other waste materials in the
vicinity of the Gulf of the Farallones generally have been limited to reconnaissance surveys of
the radioactive waste disposal sites (e.g., EPA 1975, Dyer 1976; Noshkin et al. 1978; Dayal et
al. 1979; Schell and Sugai 1980; Melzian et al. 1987; Booth et al. 1989; Suchanek and Lagunas-
Solar 1991), and investigations of potential effects associated with the sinking of the T/V
PUERTO RICAN (Robilliard 1985; PRBO 1985; Herz and Kopec 1985). Thus, the specific
effects from these previous waste discharges are poorly known, although NOAA and EPA are
presently evaluating environmental impacts from disposal of low-level radioactive waste material
in the Gulf of the Farallones.
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3.1.4 Feasibility of Surveillance and Monitoring (40 CFR 228.5[d] and 228.6[a][5J)
3.1.4.1 Surveillance
The United States Coast Guard, EPA, and the COE are responsible for surveillance and enforce-
ment of ocean disposal activities. This includes navigational surveillance and deterrence of
unauthorized disposal.
The Coast Guard's marine radar, Offshore Vessel Movement Reporting System, has an
operational range of approximately 45 km (27 nmi) from Point Bonita (i.e., the approximate
distance to the Farallon Islands). Vessel visibility on the radar screen is affected by the size of
the contact, vessel aspect, and weather. Thus, under conditions where distances are greater than
45 km or inclement weather prevails, vessels may not be visible continuously using the radar
surveillance system. Portions of Study Area 2 and all of Study Areas 3 through 5 are greater
than 45 km from Point Bonita. For these reasons, other methods of navigational surveillance,
such as Ocean Dumping Surveillance System (ODSS)-like black boxes, overflights,
navigation/operation log audits, or random checks by on-board ship riders would be necessary
for surveillance at Alternative Sites 3 through 5.
3.1.4.2 Monitoring
The EPA and the COE are responsible for the development of a site management and monitoring
plans for the ODMDS. The purposes of monitoring an offshore disposal site are to:
Document compliance with all permit requirements;
Confirm predictions of dredged material dispersion and resuspension; and
Evaluate the ecological impacts and consequences of dredged material disposal.
Elements of a disposal site monitoring program may include evaluation of: sediment chemistry,
demersal fisheries, benthic organisms, bathymetric conditions, bioaccumulation potential, and
3-19
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oceanographic conditions. A site monitoring plan designed to detect and minimize adverse
impacts through appropriate management options, will be developed and referenced in the Final
Rule and the Coastal Consistency Determination. The goals and objectives of the monitoring
plan will be defined in the FEIS, following selection of the preferred alternative.
Assuming appropriate sampling equipment and survey vessels are available, as well as contin-
gencies associated with inclement weather and sea conditions, it is expected that monitoring of
environmental effects associated with dredged material disposal operations can be performed at
any of the alternative sites. However, depending on specific monitoring requirements, some sites
may be significantly more difficult to monitor, particularly for benthic impacts due to greater
depths or residual contamination from historical waste disposal. Impacts to benthic communities
at deeper sites may be more difficult to assess because less information about benthic community
structure and disturbance response is available.
3.2 Physical Environment
This section addresses the physical characteristics of the affected environment: meteorology and
air quality (Section 3.2.1); physical oceanography (Section 3.2.2); water column characteristics
(Section 3.2.3); geology (Section 3.2.4); and sediment characteristics (Section 3.2.5). These
characteristics are addressed in the general and site-specific criteria applied to evaluations of
project alternatives Section 2.2.
3.2.7 Meteorology and Air Quality
The primary meteorological and air quality parameters relevant to ODMDS designation are the
regional climate, winds, and air quality in the vicinity of the alternative sites.
The coastal environment off San Francisco has a maritime climate characterized by a general lack
of weather extremes (Reeves et al. 1981), with cool summers and mild, wet winters. The area
has experienced drought conditions for at least five years through 1991, which has reduced the
3-20
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frequency and amount of seasonal rainfall. Weather conditions are most stable in summer and
autumn, with moderate but persistent winds diminishing to calmer conditions through the
mid-autumn period. Variable weather conditions occur during winter when series of storms
produce strong winds and high seas in the Gulf of the Farallones. Spring has fewer frontal
rainstorms and less extreme conditions, but it usually is the windiest period of the year. Typical
meteorological conditions for the coastal area off San Francisco are summarized in Table 3.2-1.
Fog occurs off the coast throughout the year, but it is most persistent during summer. Upwelling
in the waters off San Francisco tends to cool the warm, moist air masses moving eastward and
results in the formation of fog off the coast. The presence of fog often reduces visibility; for
example, the visibility at Southeast Farallon Island is less than 3 km 24% of the time in July,
compared to 11% of the time in January (Reeves et al. 1981).
Winds are an important influence on water column characteristics and currents over the
continental shelf and upper continental slope (Winant et al. 1987). For example, the strong north
to northwest winds in spring and early summer promote offshore-directed flow of surface waters
and upwelling of cool, saline, nutrient-rich waters along the coast. Relaxation periods of weak
or calm winds can result in reversals in the surface currents (Halliwell and Allen 1987). The
wind field in the region exhibits a seasonal cycle. Summer winds are driven by the pressure
gradients of the North Pacific subtropical high pressure and southwestern U.S. thermal low
pressure systems (Halliwell and Allen 1987). Coastal atmospheric boundary layer processes
modify the wind patterns within 100-200 km of the coast such that wind fluctuations are strongly
polarized in directions parallel to the coastline. The cross-shelf component of the winds in the
region is weak (Chelton et al. 1987). The mean summer winds have an equatorward alongshore
component that is relatively strong (approximately 20 knots) along the California coast (Halliwell
and Allen 1987). The strongest equatorward winds occur in April and May (Chelton et al. 1987).
Fluctuations in the winter winds exhibit greater spatial and temporal variability than that which
occurs during summer (Halliwell and Allen 1987). The relatively greater variability in the winter
winds is due to the passage of atmospheric cyclones and anticyclones moving onshore from over
3-21
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Table 3.2-1.
Meteorological Conditions for the Coastal Area off San Francisco.
Weather Elements
Wind > 34 knots (%)
Wave Height > 10 feet (%)
Precipitation (%)
Temperature > 29°C (%)
Mean Temperature (°C)
Temperature < 0°C (%)
Mean Relative Humidity (%)
Sky Overcast or Obscured (%)
Mean Cloud Cover (eighths)
Prevailing Wind Direction
Jan
1.5
15.6
9.9
0
11.7
0
82
33.2
4.9
NNW
Feb
2.5
13.1
6.9
0
11.9
0
82
29.4
4.6
NNW
Mar
1.9
16.4
7.6
0
11.8
0
80
28.2
4.7
NW
Apr
2.4
22.2
4.5
0
12.0
0
81
28.9
4.5
NNW
May
2.5
18.3
3.2
0
12.9
0
82
32.5
4.7
NNW
Jun
1.9
8.7
3.5
0
14.0
0
86
37.3
4.6
NW
Jul
0.8
7.9
3.2
0
14.8
0
87
54.3
5.4
NNW
Aug
<0.5
4.9
2.7
0
15.6
0
88
45.1
4.9
NW
Sep
. 1.1
6.2
2.4
0
16.0
0
86
34.0
4.3
NNW
Oct
1.7
10.7
2.9
0
15.4
0
84
29.2
3.3
NNW
Nov
1.4
14.9
5.4
0
14.2
0
83
27.7
4.5
NNW
Dec
2.7
16.0
8.0
0
13.0
0
81
28.3
4.5
NNW
Annual
1.7
12.5
4.9
0
13.7
0
84
34.5
4.6
NNW
to
10
Boundaries: Between 36°N and 38°N, and from 126°W eastward to coast. These data are based on observations made by ships in passage, and biased towards good weather observations.
Source: U.S. Coast Pilot #7,1976.
AK0023.W51
-------
the Pacific Ocean. Storm-driven winds occur approximately 2% of the time with average
velocities of approximately 14 m/sec (35 knots; Table 3.2-1).
Recent (1991) wind measurements from four National Data Buoy Center (NDBC) buoys off
central California—Bodega Bay (38.2°N, 123.3°W), Gulf of the Farallones (37.8°N, 122.7°W),
Halfmoon Bay (37.4°N, 122.7°W), and Monterey Bay (36.8°N, 122.4°W)—were analyzed by
Ramp etal. (1992). The surface wind vectors for 1991 (Figure 3.2-1) indicated distinct seasonal
patterns. From January through early April, the winds were variable in both speed and direction.
During the summer months, upwelling-favorable, northwest winds of 10 to 15 m/sec
predominated. Winds during autumn were still mainly equatorward, but weaker than those during
summer. Some wind reversals occurred, but they usually were weak and lasted only one day.
After the beginning of November, winter conditions were similar to those in the beginning of the
year, with strong, frequent reversals (Noble and Ramp 1992).
The large-scale wind patterns were similar at the four buoy locations; however, some small-scale
differences were apparent that reflect potentially important variations in the mesoscale forcing
to the coastal ocean. In particular, the winds measured in the Gulf of the Farallones tended to be
weaker and directed more in an eastward direction than the winds to the north and south (Ramp
et al. 1992). These differences have implications for the location and intensity of upwelling and
the subsequent advection of upwelled water along the coast (Schwing et al. 1991; see Section
3.2.2).
The air quality in most of central California is considered good. Annual summaries of air
pollutants at selected stations in the central San Francisco Bay Area and listings of the
corresponding National and California standards are presented in Table 3.2-2. During
1988-1991, concentrations of ozone, carbon monoxide (CO), nitrogen dioxide (NO2), and sulfur
dioxide (SO2) typically were below the National and California standards, whereas, concentrations
of particulate matter (PM) in San Francisco exceeded the California standard up to 15 days per
year. Air pollutants were not monitored in the vicinity of the Gulf of the Farallones (M. Basso,
BAAQMD, pers. comm. 1992). However, because the offshore regions including Study Areas
3-23
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NDBC BUOY WINDS-1991
10 M/SEC
46013 ~ BODEGA BAY I
\ I
h, ^ Ar /'• ti \,
LJ-i iv < *T-.-. i,,,- >
50 100 150 200
DAY CF YEAR
250
300
350
Figure 3.2-1. Surface Wind Vectors at Four NDBC Buoys in the Vicinity of the Gulf of
the Farallones During 1991.
Source: Ramp et al. 1992.
AK0070
3-24
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Table 3.2-2.
A. Annual Air Pollutant Summary for Central San Francisco Bay Stations During 1988-1991; and
B. California and National Standards for Individual Pollutants.
The units and standards for pollutants are described in the Explanatory Notes.
A. Annual Air Pollutant Summary
Year/Station
1991
San Francisco
San Rafael
Richmond
Oakland
1990
San Francisco
San Rafael
Richmond
Oakland
1989
San Francisco
San Rafael
Richmond
Oakland
OZONE
Max.
Hr,
5
8
5
6
6
6
6
6
8
8
10
8
National
Std.
0
0
0
0
0
0
0
0
0
0
0
0
California
Sfd.
0
0
0
0
0
0
0
0
0
0
1
0
3-Yr.
Avg.
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
CO
Max.
8-Hr.
6.5
5.6
4.6
6.8
5.6
5.0
4.0
6.1
7.0
4.0
4.1
7.5
Days
National
Std.
0
0
0
0
0
0
0
0
0
0
0
0
N02
Max,
Hr.
10
9
8
-
11
7
8
-
12
10
11
-
Days
California
Sid.
0
0
0
-
0
0
0
0
0
0
0
-
so..
Max
24-Hr,
13
-
16
-
11
-
12
-
15
-
14
-
Days
California
Std.
0
-
0
-
0
-
0
-
0
-
0
-
PMW
Annual
Meart
29.6
26.4
24.4
-
27.7
22.5
22.9
-
31.8
27.3
-
-
Days
National
Sid.
0
0
0
-
1
0
0
-
0
0
-
-
California
Std.
15
10
9
-
12
4
5
-
13
8
5
-
to
AK0024.W51
-------
Table 3.2-2. Continued.
A. Annual Air Pollutant Summary
Year/Station
1988
San Francisco
San Rafael
Richmond
Oakland
OZONE
Max.
Ht
9
10
10
10
National
Std.
0
0
0
0
California
Std.
0
1
2
1
3-Yr.
Avg.
0.0
0.0
0.0
0.0
CO
Max.
8-Hr.
12.8
5.0
5.0
6.0
Days
National
Std,
1
0
0
0
N02
Max.
Hr.
12
9
11
-
Days
California
Std.
0
0
0
-
so?
Max
24-Hr.
12
7
7
-
Days
California
Std.
0
0
0
-
PM«
Annual
Mean
29.7
27.6
-
-
Days
National
Std.
0
0
-
-
California
Std.
7
2
-
-
U)
to
AK0024.W51
-------
Table 3.2-2. Continued.
B. California and National Standards
Pollutant
Ozone
CO
N02
S02
PM
Averaging Time
1 hour
8 hours
1 hour
Annual Avg.
1 hour
Annual Avg.
24 hours
Annual Avg.
24 hours
California Standard
9pphm
9ppm
20ppm
-
25 pphm
-
50ppb
30 jig/m3
50 |ig/m3
National Standard
12 pphm
9 ppm
35ppm
5.3 pphm
-
30ppb
140 ppb
50 |ig/m3
150 jig/m
Explanatory Notes
The units for the maximums and means in the summary table are in parts per hundred million (pphm) for
ozone and nitrogen dioxide, parts per million (ppm) for carbon monoxide, parts per billion (ppb) for sulfur
dioxide, and micrograms per cubic meter (ng/m3) for suspended paniculate matter (PM10). "Days" columns
give the number of days per year on which an air quality standard was exceeded: National for CO; California
for N02 and S02; and both for Ozone and PM10. The California and National standards vary sharply for
ozone and PM10; the California standards are 25% more stringent on ozone and 67% more stringent on 24-
hour suspended paniculate matter (PM10).
Generally, the paniculate measurements are taken on the National systematic 6-day schedule. The 6-day
occurrences are reported for days exceeding the California 24-hour standards.
Source: BMQMD 1988,1989,1990,1991
AK0025.W51
3-27
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2, 3, 4 and 5 are upwind from the urbanized areas of San Francisco Bay (Holzworth 1959), the
study areas are expected to have relatively lower concentrations of air pollutants than those
measured at stations around the central parts of the Bay.
3.2.2 Physical Oceanography 40 CFR 228.6(a)(6)
Physical oceanographic parameters that are important for evaluation of an ODMDS designation
are regional and site-specific current patterns, waves, and tides, and the effects of these forces
on the transport and dispersion of dredged material. In particular, site-specific current
measurements in the vicinity of the alternative sites are used to evaluate the predicted dispersion
in the water column, and initial deposition on the seafloor, of dredged material discharged at
these sites (Sections 4.2 and 4.4). In this section, the regional current patterns are characterized
from historical data, followed by a summary of the results from recent, EPA-sponsored studies
of the currents within the LTMS study region.
i
3.2.2.1 Regional Current Patterns
The LTMS study areas are located within the California Current system, an eastern boundary
current that forms the eastern portion of the North Pacific subtropical gyre. The seasonal patterns
in the large-scale surface (upper 250 m) currents generally are divided into two seasons: an
upwelling period from March to August; and the winter or Davidson Current period from October
to February. September is a transition month and may be more like one season or the other
depending on the year being studied. The spring and summer upwelling season is characterized
by fluctuating flows with a net southward component. During October through November and
February through March, nearshore flows over the shelf and upper slope south of Cape
Mendocino move northward against weak, northerly, prevailing winds. At the same time, the
southward flow of the California Current weakens and moves offshore. Winter is a period of
storms that can produce large, storm-generated surface waves and strong fluctuating currents that
can last for 2 to 10 days. During any particular month, the flow pattern may differ significantly
from the seasonal mean conditions. Much of this variability is attributable to small-scale features
3-28
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(e.g., eddies and filaments) with short time scales and interannual variability with large spatial
and temporal scales (Chelton et al 1987).
The California Current is a broad surface flow approximately 100 to 1,000 km from shore. This
current is driven primarily by wind stress over the North Pacific Ocean, and it transports cold,
low salinity, subarctic waters. The expected mean flow in the upper few hundred meters is
equatorward (i.e., towards the southeast) at speeds less than 10 cm/sec. Satellite-tracked drifter
observations (Brink et al. 1991) show slow, equatorward movement of surface waters that is
superimposed on an energetic mesoscale eddy field, displacing the flow 200 to 400 km to the east
and west as it moves slowly towards the south.
Within the California Current system are two poleward flows: the Coastal Countercurrent and
the California Undercurrent (Hickey 1979; Chelton 1984; Neshyba et al. 1989). The Coastal
Countercurrent flows northward over the continental shelf, inshore from the California Current.
The Countercurrent typically is only 10 to 20 km wide, with velocities less than 30 cm/sec (Kosro
1987). It is broader and stronger in the winter (October through early March), when it
occasionally covers the entire continental shelf and is referred to as the Davidson Current;
however, it remains strongest nearshore (Huyer et al. 1978). The Coastal Countercurrent has
been observed both north and south of the study region. Observations north of the Gulf of the
Farallones were made by the Coastal Ocean Dynamics Experiment (CODE; Lentz 1991) during
1981-1982 along a relatively straight stretch of coast between Point Arena and Point Reyes,
California. During the upwelling season, the Countercurrent appeared whenever equatorward,
upwelling-favorable winds relaxed and disappeared when the winds were unusually strong (Send
et al. 1987; Winant et al. 1987).
The California Undercurrent is a strong poleward flow over the slope. This current has been
observed off southern California (Lynn and Simpson 1990), Point Conception and Point Sur
(Chelton et al. 1988; Tisch et al. 1991), Northern California (Freitag and Halpern 1981), Oregon
(Huyer et al. 1984; Huyer and Smith 1985), Washington (Hickey 1979), and Vancouver Island,
3-29
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British Columbia (Freeland et al. 1984). The position, strength, and core velocity of the
undercurrent vary spatially and at different times of the year, although a maximum poleward
velocity of around 30 cm/sec typically occurs between 150 to 300 m depth in slope waters 500
to 1,000 m deep.
All the currents described above are mean flows that are fairly steady over periods of many
months. However, the characteristics of the mean flows are subject to considerable interannual
variability. El Nino/Southern Oscillation (ENSO) events can alter the mean current field on a
year-to-year basis; evidence from the tropical Pacific indicates that 1991-1992 was an ENSO
year. ENSO events can cause anomalous atmospheric conditions and anomolous oceanic
conditions in the northeast Pacific. Weakened equatorward or poleward winds may cause
weakened upwelling and onshore transport, which leads to warmer than usual water temperature.
The ENSO events also can produce very low frequency wave motions at low latitudes which then
propagate poleward into the northern hemisphere along the continental shelf and slope. Huyer
and Smith (1985) showed that the northward flow over the continental shelf was twice as strong
during the El Nino winter of 1982-83 than during the preceding and subsequent "normal" years.
A basic feature of the circulation along the entire central coast is coastal upwelling, which causes
continental shelf water to exchange with slope water. An "upwelling front" forms between the
upwelled water and the warmer, less dense water further offshore. North of Cape Blanco,
Oregon, the upwelling front is fairly straight along the coast, but to the south, large meanders
develop and form "cold filaments" of freshly upwelled water that can extend more than 200 km
offshore. Filaments are observed most commonly near coastal promontories such as Cape
Mendocino, Point Arena, Point Reyes, and Point Sur. The Point Arena filament was observed
in six different surveys during July and August 1988 (Huyer et al. 1991). Offshore velocities
along the northern side of the filament approached 100 cm/sec (2 knots), which is far greater than
the large scale mean flow towards the south. The Point Reyes filament is less studied and less
well understood, but it is expected that large cross-shore transport is associated with the Point
3-30
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Reyes feature as well, which potentially can affect suspended particle transport in the vicinity of
the alternative sites. Because the filaments are associated with upwelling, they are not commonly
seen during winter.
Mixed semidiurnal tides occur on the west coast in the vicinity of San Francisco. The strongest
tidal current component is either the principal lunar or the luni-solar diurnal tide, which have
periods of 12.4 hours and 23.9 hours, respectively. Diurnal tides are strongest on the shelf in the
Gulf of the Farallones (Noble and Gelfenbaum 1990), with tidal amplitudes between 6 and 9
cm/sec. Lunar tidal currents are strongest on the slope adjacent to the Gulf of the Farallones,
with amplitudes from 2.3 to 4.4 cm/sec near Study Area 5 (Noble 1990). Semidiurnal and
diurnal tides together account for 35 to 60% of the total variability in the current records on the
shelf, and from 15 to 33% of the variability on the slope. These tidal currents may promote the
resuspension of material deposited on the seabed and dispersion of material suspended in the
water column.
Wave observations at a buoy 7 nmi southwest of the Golden Gate Bridge (37.62°N; 122.95°W)
are summarized by wave period and wave height in Table 3.2-3. Bottom current motions
associated with large, storm waves can affect scouring and resuspension of sediments, particularly
on the continental shelf. Also, severe wave conditions (heights greater than 3 m with periods less
than 11.7 seconds or wave heights greater than 5 m) can limit or restrict dredged material barge
transit to the alternative sites (Section 3.1.2; Tetra Tech 1987).
3.2.2.2 Study Region-Specific Currents
Beginning in 1991, EPA sponsored a one-year study of the circulation in the Gulf of the
Farallones and over the adjacent continental slope to develop a better understanding of the
physical processes and support predictive modeling of the deposition and fate of dredged material
at the LTMS study areas (see Section 4.4). The following, modified from Noble and Ramp
(1992), summarizes the information relative to the study area locations.
3-31
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Table 3.2-3. Wave Observations (Percent Occurrence) Based on U.S. Army Corp of Engineers (COE) Wave Data at Station
20 (Dates Unspecified), Located Approximately 7 nm southwest of the Golden Gate Bridge, San Francisco,
California. Bold numbers represent percentage of total observations exceeding criteria (1) wave heights exceed
three meters (9.8 ft.) and wave periods are less than 11.7 seconds; and (2) wave height exceeds 5 meters (16.4
ft.) regardless of wave period.
Wave Height
(m)
0-0.9
1.0-1.9
2.0-2.9
3.0-3.9
4.0-4.9
5.0-5.9
6.0-6.9
7.0-7.9
8.0-8.9
9.0-9.9
10.0+
TOTAL%
4,4-6,0
0.16
1.73
2.04
0.05
0.00
0.00
0.00
0.00
0.00
0.00
0.00
3.97
6,1-8.0
0.49
3.97
2.71
0.96
0.17
0.00
0.00
0.00
0.00
0.00
0.00
8.31
8.1-9.5
0.52
8.56
4.76
1.15
0.46
0.09
0.00
0.00
0.00
0.00
0.00
15.54
9.6-10.5
0.03
5.35
7.14
1.07
0.32
0.13
0.01
0.00
0.00
0.00
0.00
14.06
Wave Period (seconds)
10.6-11,7 118-13,3
0.01
2.68
11.01
3.89
0.58
0.21
0.03
0.00
0.00
0.00
0.00
18.41
0.01
0.72
7.84
11.14
3.35
0.39
0.03
0.00
0.00
0.00
0.00
23.48
13.4-15,3
0.00
0.04
1.26
4.84
5.48
1.81
0.29
0.04
0.00
0.00
0.00
13.76
15.4-18.1
0.00
0.06
0.10
0.35
0.56
0.80
0.44
0.09
0.04
0.01
0.00
2.46
18.2-22,2
0.00
0.00
0.02
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.02
u>
U)
to
Source: Modified from COE (1987).
AK0026.W51
-------
The EPA study included a main line of the moorings, which contained Stations A through D, to
monitor the changes with water depth in the physical oceanographic parameters (Figure 3.2-2).
Changes in water depth typically cause the largest spatial gradients in the circulation and
sediment transport pathways. Station A was on the shelf in 92 m of water, Station B was on the
upper slope in 400 m between Study Areas 2 and 3, and Stations C and D were on the mid- and
lower-slope at depths of 800 m and 1,400 m adjacent to the southern boundary of Study Area
3. Stations E and F represented a secondary mooring line in the array. Station E was located
along the eastern edge of Study Area 5, and Station F was shoreward of Study Area 5. Data
from these moorings were used to determine how the circulation patterns change with distance
along the isobaths. Each mooring in the array had between three to six instruments that
measured current speed, direction, and temperature at specific locations in the water column
(Noble and Ramp 1992).
3.2.2.3 Outer Shelf (Study Area 2) Currents
Currents over the outer shelf were measured at Station A, located within Study Area 2
(Figure 3.2-3). Evaluations of currents at Site A are obscured by gaps in the data, but the
available data suggest a vertically coherent flow during the first half of the year. Fluctuations
in the alongshore component were quite similar and nearly uniform in magnitude with depth,
weakening only slightly towards the bottom. There was a tendency for the along-isobath flow
at mid-depth to veer toward the coast. The average mid-depth, cross-shelf flow had a mean
speed of 2.4 cm/sec. However, shoreward flow was not observed near the surface or 12 m above
the seabed.
Tidal currents were the other strong component of the currents measured over the shelf. The
principal diurnal tides and the principal semidiurnal tides each can have speeds of 8 to 9 cm/sec
(Kinoshita et al. 1992). Hence, the tidal and lower frequency (subtidal) currents can combine
to generate strong currents. Maximum current speeds over the shelf ranged between 40 to 60
cm/sec, and the maximum speed near the seabed was 47 cm/sec. These currents would be strong
enough to move fine sand (see Section 3.2.4.2).
3-33
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Moored station | W I Wind station
Sea level station
38°N -
37°30'N -
Transverse Mercator Projection
Scale
0 5 10 15 20
Cordell Bank
50m
200m
500 m V^ Farallon
. Islands
Ol i s~ San
OLt Francisco
San
Francisco
Bay
Alternative
SiteS
Alternative
Gumdnfo $ Site 3
Seamount
-123°30>w
-123°w
Figure 3.2-2. Locations of Current Meter Stations A Through F.
Source: Noble and Ramp 1992.
AK0071
3-34
-------
Station A
0>
-o
E
CO
30 -i
0 -
-30-
10 meters
u>
U>
Ui
TJ
if
Q. E
Eii
0)
30 -i
o-
-30
30 -i
-30
Figure 3.2-3.
50 meters
80 meters
^Hfift***1*
i \ '"
Mar May
1991
July
Sept
Nov
Jan
1992
Subtidal Currents at Station A.
Each line represents the magnitude and orientation of the current vector. A line pointing
toward the top of the page represents poleward flow along the shelf. Currents flowing toward
the coast point to the right.
Source: Noble and Ramp 1992.
-------
3.2.2.4 Slope (Study Areas 3 through 5) Currents
Slope currents in the region of the Gulf of the Farallones during 1991 and 1992 can be grouped
by depth ranges. Near-surface currents are those above 75 m depth. Mid-depth currents are
between 75 and 800 m and at least 50 m above the seabed. Deep currents are below 800 m and
at least 50 m above the seabed, and near-bottom currents are 10 to 15 m above the seabed. The
currents within these different depth ranges share similar characteristics, and the coupling among
currents is much stronger within discrete depth ranges than the coupling between currents in
separate depth ranges.
3.2.2.5 Near-Surface Currents Over the Slope
Near-surface currents over the slope are well studied only at Station C. Spring currents at this
station were characterized by a strong equatorward event during April which reached a depth of
at least 250 m. This event likely was due to an anticyclonic (clockwise) eddy or a southward
flowing upwelling filament, and not attributable to wind. Similar equatorward events also were
observed at this time at Stations D and E to depths exceeding 800 m. The strength and duration
of the event at 250 m depth was about the same at Stations C and D.
At times, the flow at Station C at 10 m depth was poleward at speeds greater than 30 cm/sec.
A portion of this flow likely represented a surfacing of the California Undercurrent which is
common during autumn and winter (Section 3.2.2.1). The near-surface diurnal and semidiurnal
tidal currents have velocities up to 5 or 6 cm/sec (Kinoshita et al. 1992), which are not sufficient
to reverse the dominant flow direction of the near-surface currents. The tidal currents can act
to disperse materials suspended in the near-surface water, but, being rotational in nature, they
would not cause large changes in the fate of those materials in the water column or in the region
of deposition (Noble and Ramp 1992).
3-36
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3.2.2.6 Mid-Depth Currents Over the Slope
A wedge-shaped region, generally including Study Areas 3, 4, and 5, can be described where
mid-depth currents along the isobaths are strongly correlated both horizontally and vertically
(Figure 3.2-4). The California Undercurrent traditionally has been observed in this region. The
offshore boundary of this flow field extended seaward of the study region and was not well
delineated.
The persistent patterns in mid-depth currents that flow throughout the wedge-shaped region were
not observed at Station F, located shoreward of Study Area 5. Currents at Station F were weak
and disorganized, with a much higher variability than currents observed over the continental slope
at locations elsewhere along the California coast Current speeds in 150 m at Station F were
slower than the equivalent currents at Station B, even though both flow toward the northwest in
the spring and early summer, and the poleward currents at Station F do not extend to 250 m.
These characteristics suggest that Station F was just east of the inshore boundary of the
correlated, wedge-shaped flow field observed at the other stations on the slope.
The most prominant feature of the mid-depth currents over the slope is a burst of strong poleward
flow lasting from mid-April to September. Similar bursts of poleward flow have been observed
in three-year records over the slope off Point Sur (Ramp et al. 1991). Such burst events are not
seasonal. Hence, it is not clear if the poleward bursts observed in the EPA data records are part
of a seasonal cycle or if they appear randomly at different times in other years.
Both the persistent poleward flow and the strong vertical correlations in the alongslope currents
weakened as the year progressed. The amplitude of the mid-depth flow was reduced at all
stations, and the direction became more erratic from mid-August through mid-November. A
partial return to the strong poleward flow occurred after mid-November.
The daily, mid-depth, tidal currents have combined amplitudes less than 5 cm/sec (Kinoshita et
al. 1992). The semidiurnal, mid-depth, tidal currents are slightly stronger, with a combined
3-37
-------
38°N -
37°30'N -
Transverse Mercator Projection
Scale
0 5 10 15 20
-123°30-w
-123°w
-122°30-w
Figure 3.2-4. Schematic Representation of the Three-Dimensional Structure of the
"Wedge-Shaped" Region of Coherent Mid-Depth Flow Over the Slope.
Source: Noble and Ramp 1992.
AK0073
3-38
-------
amplitude that can reach 10 cm/sec, but which generally are less than 8 cm/sec. Hence, neither
of these tidal constituents can significantly alter the lower frequency current regime described
above. The main effect of the tidal components is to increase the cross-slope flow and dispersion
of material suspended in the water column across isobaths.
3.2.2.7 Deep Currents Over the Slope
Current measurements in water depths of 1,420 m at Station E suggest that deep currents over
the slope are weak and variable (Figure 3.2-5). The deep currents are parallel to bottom
contours, but the velocities tend to be less than 10 cm/sec. The mean current speed is 1 cm/sec
toward the northwest (Kinoshita et al. 1992). The tidal currents have amplitudes less than 4
cm/sec, which are somewhat smaller than those at shallower depths. Because the lower
frequency currents also are small, the tidal currents can act to reverse both the net along- and
cross-slope flow (Kinoshita et al. 1992).
3.2.2.8 Near-bed Currents Over the Slope
Characteristics of currents within 20 m of the seabed cannot be predicted reliably from
measurements made above the bed because they are different from the currents in the overlying
water column. Near-bed currents also are different from those measured at adjacent sites. For
example, near-bed currents at Station B appear unrelated to near-bed currents at Station C even
though currents in the overlying water column share similar characteristics. Near-bed currents
flow along the isobaths, but their amplitudes are much smaller than flows in the overlying water
column at most stations on the slope. Bottom currents at Stations B (400 m) and C (800 m)
range from 10 to 15 cm/sec, whereas currents at 250 m depths at these stations reach speeds of
30 cm/sec or more. These differences occur because near-bed currents are more strongly
controlled by topographic features than currents higher in the water column.
In contrast to the overlying flow, the near-bed currents at Stations B and D have no definite
seasonal or temporal patterns. The mean current directions at Stations B and D are weakly
3-39
-------
Station E
1
a,
•o
ft
30
-30
250m
o>
T3
30 -i
0-
-30
400 m
u>
-U
O
0>
•o
•= to"
30 -,
o-
-30-
m
-------
equatorward, at speeds of 0.7 and 0.2 cm/sec, respectively (Kinoshita et al. 1992). In addition,
particular flow events in the near-bed currents last only a few days, which is much shorter than
the duration of events in the overlying water column. Near-bed flow at Station C was poleward
for most of the observation period, although current flow to the southeast was observed during
a few short periods. Near-bed currents at Station E were small but had a steady flow to the
northeast up a small unnamed submarine canyon, and across the striked local isobaths. This
shoreward, near-bed flow at Station E may be caused by interactions between the tidal current
and local topography (Noble and Ramp 1992).
One of the most notable features of the tidal currents over the slope was the increase in
amplitude of both the diurnal and semidiurnal tidal constituents towards the bottom at some
locations (Kinoshita et al. 1992). Amplification of diurnal and semidiurnal tides can result in
tidal currents which are two to three times stronger at the bottom than in overlying waters. This
difference may promote resuspension and transport of larger grain sized sediment than would
otherwise occur in the absence of "bottom trapping". Enhancement of tides by topographic
features also can result in unusually strong mean flows which can result in unidirectional
sediment transport. This may occur at Station E, where a steady up-canyon flow was observed.
However, amplification of bottom tidal currents was not observed at Station F, possibly due to
the relatively steep bottom slope that does not allow this condition to occur. Bottom trapping
of the tidal currents has been observed previously over the continental shelf off Point Sur
(Sielbeck 1991).
3.2.2.9 Summary of Observed Currents
The observed circulation over the continental shelf and slope near the Farallon Islands can be
summarized as follows. The flow over the shelf and slope were not strongly coupled. Over the
continental shelf and inshore of the Farallon Islands, the observed flow was coupled closely with
the local surface wind stress: equatorward when the wind was equatorward, and poleward when
the wind was slack or poleward. The flow also may be affected by outflow from the San
Francisco Bay. This aspect of the flow has not been studied previously; hence, the magnitude
3-41
-------
of the effect is unknown. On average, the mean surface circulation from the shelf break seaward
is likely equatorward during the upwelling season, with a velocity less than 10 cm/sec. Surface
currents were variable in the other seasons, with speeds and directions changing partially in
response to variable surface wind stresses.
Over the continental slope, at depths between 100 and 1,000 m, the flow likely is poleward due
to the presence of the California Undercurrent. These currents probably flow poleward
throughout the year, but their velocities vary due to conditions not yet fully understood. Strong,
persistent bursts (greater than 40 cm/sec) can occur during all seasons for periods of four months
or more. The basic flow patterns will be perturbed occasionally by the Point Reyes coastal
upwelling jet, which (based on satellite observations of sea surface temperature) sometimes
swings southward and crosses the northern corner of the region, and also by mesoscale eddies
that move into the area. The frequency of such events is unknown, but at least one such event
per year is likely. The upwelling process, which moves water in the upper layers from the slope
to the shelf, is weaker here than at other sites on the California coast. The tidal currents over
the continental shelf are strongly diurnal and are relatively more important than tidal currents
near the continental slope (Noble 1990). Because wave-induced currents generated during winter
storms can reach depths of 100 m or more, fine grained material likely will be resuspended over
most areas of the shelf (Noble and Ramp 1992). The general absence of fine-grained sediments,
and the presence of sand ripples throughout Study Area 2 (SAIC 1992c; see Section 3.2.4.2)
support these indications of strong current-sediment interactions. The mean currents will carry
suspended materials mainly along the isobaths. The jets, eddies, and tidal currents will disperse
the suspended materials across isobaths.
32.3 Water Column Characteristics 40 CFR 228.6(a)(9)
Water column characteristics include temperature, salinity, hydrogen ion concentrations,
turbidity/light transmittance, dissolved oxygen, and the concentrations of major nutrients, trace
metals, and trace organic contaminants.
3-42
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3.2.3.1 Temperature-Salinity Properties
Recent hydrographic and current measurements indicate that the outer shelf and slope regions of
the Gulf of the Farallones are a dynamic area (Ramp et al. 1992). Current and water mass
variability occurs on time scales from days to months, corresponding to meteorological and
mesoscale events and seasonal patterns. Surface waters show a great deal of variability in
temperature-salinity (T-S) properties. For example, during recent EPA-sponsored surveys (Ramp
et al. 1992), near-surface waters "represented a mixture of three primary water types: (1) recently
upwelled water from a source primarily to the north of Point Reyes; (2) offshore water from the
large-scale California Current system; and (3) outflow from San Francisco Bay. The
characteristics and importance of each water type in the Gulf vary seasonally and on shorter (i.e.,
event-related) time scales.
Water discharged from San Francisco Bay into the Gulf of the Farallones has a higher
temperature and lower salinity, and therefore lower density, than the water in the Gulf. The
long-term average salinity at S.E. Farallon Island is 33.4 ppt, whereas, at Fort Point on the south
side of the Golden Gate, the average salinity is 29.9 ppt (Peterson et al. 1989). Historically,
salinities at both locations are lowest during winter and spring when the Delta outflow is highest.
Due to its lower density than ambient waters, the outflow from San Francisco Bay is confined
in the Gulf of the Farallones to the surface layer.
In the vicinity of the alternative sites, a typical temperature-versus-depth profile during summer
consists of an isothermal surface layer that is tens of meters thick. Beneath the surface mixed
layer is a region of rapidly changing temperatures referred to as the thermocline. Below the
thermocline, the water temperature changes gradually with depth, becoming nearly isothermal
again. The depth of the surface mixed layer and the degree of vertical temperature (density)
stratification in the Gulf of the Farallones varies depending on the characteristics and extent of
mixing of the various water masses.
3-43
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Water temperatures below 4.0°C with salinities greater than 34.5 parts per thousand (ppt) are
associated with Pacific Common Water, which has a stable T-S relationship throughout the North
Pacific. Contrasting T-S properties associated with Subarctic Intermediate Water (found offshore
in the California Current) and Equatorial Water (over the continental slope in the California
Undercurrent) are found at temperatures between 4.8 and 7.0°C. Subarctic waters also are
evident, and although the horizontal scale of this intrusion of Subarctic water was not resolved,
it is indicative of the active mixing which must occur in the region at these depths.
Considerable seasonal variability in surface water temperatures and salinites reflect large-scale
current patterns, outflow from the Bay, and the presence of mesoscale features. Figure 3.2-6
shows satellite images of surface water temperatures during winter (February 1991) and spring
(May 1991) and illustrates the variability in surface temperatures. The presence of numerous
mesoscale features in both the water mass distribution and currents demonstrates that there was
no overall persistent pattern among the study areas. However, it was apparent that the outflow
from San Francisco Bay was confined to the inner continental shelf and did not influence the
water column at the study areas (Ramp et al. 1992).
3.2.3.2 Hydrogen Ion Concentration (pH)
The pH of seawater within the LTMS study areas was not measured during the recent EPA
surveys, but is expected to be within the range of 7.8 to 8.3 measured previously in other areas
of the Gulf of the Farallones (e.g., Nybakken et al. 1984; ffiC 1982). Seawater pH values likely
are similar at all of the LTMS study areas, although some minor spatial differences may be
related to localized effects from primary production by plankton.
3.2.3.3 Turbidity
Water turbidity or light transmittance properties on the continental shelf near the Golden Gate
are affected by seasonal and tidal flows of turbid waters from San Francisco Bay. The location
and aerial extent of the outflow plume in the nearshore surface waters off San Francisco change
3-44
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Color figures follow.
Figure 3.2-6. Satellite Images of Sea Surface Temperatures Within the LTMS Study
Region During (A) February and (B) May 1991.
Temperature ranges are indicated by different colors; red to white represents the warmest
water; dark blue represents the coldest.
Source: Noble and Ramp 1992.
AK0160 3-45
p. 1 o(4
-------
Figure 3.2-6.
AK0160
p. 2 of 4
Satellite Images of Sea Surface Temperatures Within the LTMS Study
Region During (A) February 16,1991.
Temperature ranges are indicated by different colors; red to white represents the warmest
water; dark blue represents the coldest.
Source: Noble and Ramp 1992.
3-46
-------
Figure 3.2-6.
AK0160
p. 3 of 4
Satellite Images of Sea Surface Temperatures Within the LTMS Study
Region During (B) May 15,1991.
Temperature ranges are indicated by different colors; red to white represents the warmest
water; dark blue represents the coldest.
Source: Noble and Ramp 1992.
3-47
-------
This page intentionally left blank.
Figure 3.2-6. Continued.
AK0160 3-48
p. 4 of 4
-------
seasonally. During recent hydrographic surveys of the region (Ramp et al. 1992), outflow from
San Francisco Bay was observed to the north of the Golden Gate during August, directly off the
Golden Gate during November, and to the south and farther offshore during February 1991. The
distribution of the outflow plume may have been influenced by prevailing nearshore wind stress.
None of the observed plumes extended very far offshore, likely due to drought conditions.
However, previous studies noted a plume of turbid water extending approximately 46 km offshore
during peak spring flows from the Bay (Carlson and McCulloch 1974). The relative spatial
extent of the plume is reduced in summer when flows from the Bay are minimal.
In waters over the continental shelf off Point Reyes to Point Arena (i.e., the CODE study region),
Drake and Cacchione (1987) measured light transmittance values of 65-90 percent transmittance
per meter (%/m) throughout the water column. Depth-related patterns in light transmittance
suggested the presence of a subsurface lens and bottom layers of turbid (nepheloid) waters. The
development of these subsurface lenses may be associated with previously upwelled waters
containing high plankton concentrations that sink during periods of relaxation of
upwelling-favorable winds. Turbid waters containing high plankton concentrations occur along
the front between low density surface water offshore and recently upwelled water over the
continental shelf. The location of the front may then move in an onshore or offshore direction
in response to local alongshore winds.
Within the LTMS study areas, turbidity probably is affected by seasonal changes in suspended
particle concentrations related to primary productivity, surface current patterns and the presence
of fronts, and the extent of bottom sediment resuspension on the shelf or at the shelf break.
Light transmissivity measurements made at Study Area 5 in September 1991 showed values of
88-90 %/m throughout the water column; there was no evidence of a turbid nepheloid layer in
any of the sampled water layers (SAIC 1992a). Similarly, Nybakken et al. (1984) measured
80-90 %/m light transmittance throughout the water column at a shelf-edge location (Station 2;
see Figure 2.1-3), whereas, relatively lower values of 10-80 %/m were measured at a site over
3-49
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the continental shelf. The low transraittance levels at the continental shelf site may be related
to resuspension of sediments near the bottom and inorganic suspended particles or phytoplankton
within the near-surface mixed layer (Nybakken et al. 1984).
Few measurements of suspended solids concentrations have been made within the region, and no
measurements of total suspended solids (TSS) were performed within the LTMS study areas
during the EPA surveys. However, IEC (1982) measured TSS concentrations of 0.08 to
2.51 mg/1 in waters near the shelf-break (the 100-Fathom disposal site) in April 1980, and
Gordon (1980) measured TSS concentrations of 0.3 to 2.9 mg/1 within the surface 25 m at two
continental shelf sites in the Gulf of the Farallones during March and August 1979. Nearshore
areas affected by the plume from San Francisco Bay are expected to have significantly higher
water column concentrations of TSS and associated higher turbidity levels than waters further
from shore.
3.2.3.4 Dissolved Oxygen
Dissolved oxygen concentrations are important because depressed levels can affect the diversity
and abundances of marine organisms. In upwelling areas, such as the central California coastal
zone region, organic material associated with high primary production settles through the water
column and consumes oxygen as it sinks. The depletion of dissolved oxygen at depths of about
500 to 900 m can produce an oxygen minimum zone (OMZ) (Broenkow and Green 1981).
Intersection of the OMZ with the seafloor potentially can affect the distribution of
oxygen-sensitive taxa. Whereas the cores of some OMZ are faunally depauperate (Rhoads et al.
1991), the edges of the OMZ are known to be highly productive, especially with respect to
bacteria (Mullins et al. 1985; Rhoads et al. 1991).
Composite profiles of dissolved oxygen (DO) concentrations measured in July and
September 1991 within Study Areas 3 and 5 are shown in Figure 3.2-7. The DO concentrations
in surface waters are approximately 8 mg/1. Concentrations decline through the mixed layer, and
reach minimum values of about 0.5 mg/1 at a depth of 800 m. Below 800 m, DO concentrations
3-50
-------
IT
0
^^
0)
E,
f.
0
Q
0-r
-
-
400-
800-
-
1200-
•
•
.
1600-
m
•
2000-
2400-
2800-
3200
D
S3
3i
/w
till
Dr-
»
or
Q
i^J
/t\
1 1 1 1
U
\yi ^
TN? A
K7.
\t»
^n
B-7
1 1 1 1
7 C
._
' D
B^8
1 I 1 1
™
Oxic
Dysoxic
Oxic
1 1 1 1
i i i i
_i
i i i i
1 1 i i
01 2345678
Dissolved Oxygen (mg/l)
Z 83-5(9/91) + 83-9(9/91) * 83-14(9/91)
X Leg I (7/91) D Leg II (7/91) j
-
Figure 3.2-7.
AK0076
A Composite Profile of Dissolved Oxygen Concentration in the Water
Column Over the Continental Slope off San Francisco and the Gulf of the
Farallones.
Data were collected at Study Area 5 in July 1991 and at Study Area 3 in September 1991.
Oxygen concentrations in the oxic zones are > 2.8 mg/l and in the dysoxic zone range from
0.28-2.8 mg/l.
Source: SAIC 1992c.
3-51
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increase to over 3 mg/1 at depths greater than 2,000 m. This DO concentration/depth pattern is
similar to those reported for other portions of the central California continental margin (e.g.,
Thompson et al. 1985). Nybakken et al. (1984) measured dissolved oxygen concentrations of
approximately 5.1-8.6 mg/1 over the continental shelf and shelf edge in the Gulf of the
Farallones; surface waters were supersaturated with oxygen, while bottom waters were at about
45% saturation. Similarly, dissolved oxygen concentrations averaged over a period of 18 years
for CalCOFI Station 60052 (37°51.8N; 123°03.8W; offshore from Point Reyes and north of the
Farallon Islands) over the continental shelf ranged from 8.7-10.1 mg/1 at the surface to 5.3-7.3
mg/1 at 50 m. The higher concentrations typically were measured in January and lower
concentrations occurred in October.
3.2.3.5 Nutrients
Nutrient concentrations are influenced by seasonal current patterns, upwelling, and biological
uptake by marine plants (phytoplankton). Outflow of water from San Francisco Bay may
represent an additional source of nutrients to nearshore waters. Typically, nutrient concentrations
increase with depth due to surface depletion by phytoplankton and settling of detritus followed
by subsurface remineralization and release of nutrients. However, upwelling of deeper waters
transports nutrients into the surface mixed layers.
Measurements from CalCOFI surveys in the vicinity of the Gulf of the Farallones indicate that
phosphate concentrations in surface waters (10 m depth) typically range from 0.25 to 2.0
micromoles per liter (uM/liter; which is the mass equal to the molecular weight of the compound
per unit volume of seawater). Concentrations increase with depth below the surface mixed layer;
concentrations up to about 4 uM/liter occur at depths greater than 1,000 m. Nitrate
concentrations in surface (10 m) and mid-depth (100 m) waters range from < 1 to 20 uM/liter
and from 10 to 30 uM/liter, respectively. Silicate concentrations in surface and mid-depth waters
range from 1 to 40 uM/liter and from 20 to 50 uM/liter, respectively. Profiles of nitrate,
phosphate, and silicate concentrations measured at CalCOFI Station 60060 (37°36.8'N,
3-52
-------
123°36.5'W; southwest from the Farallon Islands and Study Area 5) over the continental slope
during July 1984 are shown in Figure 3.2-8.
No measurements of nutrient concentrations were performed during the EPA surveys of the
LTMS study areas. Differences in nutrient concentrations between Study Areas 3 through 5 are
expected to be minimal, especially within the subsurface layers, although localized upwelling
events and small-scale variability in phytoplankton productivity may result in some short-term
spatial differences within surface waters. As mentioned, nutrient concentrations within the shelf
region, including Study Area 2, are expected to be influenced to a greater extent by the Point
Reyes upwelling filament and outflow from San Francisco Bay than are Study Areas 3 through 5.
3.2.3.6 Trace Metals
Trace metal concentrations in seawater within the LTMS study areas were not measured during
the EPA and Navy surveys. However, data from previous measurements of seawater trace metal
concentrations in the vicinity of the Gulf of the Farallones are presented in Table 3.2-4.
Concentrations of individual trace metals in the surface waters of the Gulf of the Farallones are
characterized by pronounced spatial and temporal variability (Nybakken et al. 1984). These
differences are expected to reflect upwelling patterns, transport and mixing of outflow from San
Francisco Bay, resuspension of bottom sediments by currents and wave action, and atmospheric
deposition of anthropogenic metals (e.g., lead from gasoline additives). Large differences
between Study Areas 3, 4, and 5 in the seawater trace metal concentrations would not be
expected. Relatively higher concentrations of selected metals may occur within Study Area 2,
depending on the Bay outflow and current conditions.
The NOAA National Status and Trends (NS&T) Program and California "Mussel Watch"
Program measured contaminant concentrations in tissues of intertidal mussels (Mytilus spp.) as
an indicator of water quality trends. Waters near the Farallon Islands typically contain low
concentrations of most trace metals as compared to sites along the California coast located near
urban areas or discrete sources of pollutants. However, the Farallon Islands mussels historically
3-53
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10 20
Concentration (UM/L)
30 40 50 60
70 80
90
50
100
SIO3 * PO4 • NO3
Figure 3.2-8. Vertical Profiles of Silicate, Phosphate, and Nitrate Concentrations at
CalCOFI Station 60060 (37°36.8'N, 123°36.5'W) in July 1984.
Source: CalCOFI Database (1991).
AK0077
3-54
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Table 3.2-4.
Trace Metal Concentrations in Seawater in the Vicinity of the Gulf of the Farallones.
Study Area
(Source)
Continental Shelf and
Shelf Edge
(Nybakken era/. 1984)
Continental Shelf
(Gordon 1980)1
100-Fathom Site
(IEC 1982)'
Depth (m)
10
20
40
100
2
6
20
25
55
Concentration (mg/Uter)
Cd
0.02
0.01-0.04
0.03-0.05
0.02-0.04
0.047
0.030
0.046
0.045
0.060-0.61
Cu
0.14-0.15
< 0.005-0.07
0.03-0.27
0.07-0.13
0.16
0.16
0.14
0.10
Fe
0.51-1.4
0.59-1.1
1.5-2.7
0.17-0.59
Mn
< 0.005-0.01
0.21-0.51
< 0.005-1 .5
0.01-0.10
0.41
0.99
0.39
0.60
Ni
0.42-0.53
0.17-0.23
0.29-0.48
0.23-0.39
0.24
0.34
0.21
0.33
Pb
<0.6
<0.6
<0.6
<0.6
0.15
0.028
0.049
0.020
0.22-0.38
Zn
0.52-0.53
< 0.005-0.18
0.33-2.1
< 0.005-0.27
0.21
0.12
0.095
0.17
Hg
0.018-0.019
AK0027.W51
-------
Table 3.2-4.
Continued.
Study Area
(Source)
Continental Slope
(Bruland 1980)
Depth (to)
25
50
100
250
750
1,500
3,000
Concentration: (mg/Liter)
Cd
0.0066
0.0064
0.037
0.082
0.115
0.107
0.100
Cu
0.084
0.085
0.082
0.081
0.119
0.135
0.221
Pfr
MR
Ni
0.217
0.207
0.263
0.358
0.522
0.620
0.627
Pb
In
0.016
0.014
0.054
0.160
0.363
0.507
0.574
H0
'Dissolved and participate fraction concentration
AK0027.W51
-------
contained high lead concentrations relative to concentrations in mussels from several central
California locations. The source of the lead is unknown; however, the location of the Farallon
Islands upwind from potential combustion sources would minimize atmospheric deposition
sources (Farrington et al. 1983; Goldberg and Martin 1983). Elevated concentrations of some
elements including cadmium in mussels at the Farallon Islands probably are related to upwelling
of subsurface waters that are relatively enriched with these elements (Farrington et al. 1983;
Bruland et al. 1991).
3.2.3.7 Hydrocarbons
Petroleum and synthetic (anthropogenic) hydrocarbon concentrations in waters within the LTMS
study areas were not measured during the EPA and Navy surveys. However, concentrations are
expected to reflect current transport and mixing with outflow from San Francisco Bay,
atmospheric deposition, particularly of combustion-derived compounds, and episodic inputs from
oil/petroleum product spills (e.g., the R/V PUERTO RICAN) or discharges. Nevertheless,
appreciable differences in hydrocarbon concentrations between Study Areas 3, 4, and 5 would
not be expected. Slightly higher concentrations of hydrocarbons may occur within Study Area 2,
depending on Bay outflow and current patterns.
Nybakken et al. (1984) reported very low concentrations of petroleum hydrocarbons (140-280
ng/liter) in outer continental shelf waters (Station 2; see Figure 2.1-5). Similarly, deLappe et al.
(1980) reported that the polynuclear aromatic hydrocarbons (PAHs) phenanthrene and pyrene in
waters near the Farallon Islands were below analytical detection limits. Organochlorine
compounds measured by IEC (1982) in seawater collected at the 100-Fathom site were
nondetectable. However, Nybakken et al. (1984) measured concentrations of total (dissolved and
paniculate) polychlorinated biphenyls (PCBs) of 24-105 ng/liter, dichloro-
diphenyldichloroethylene (DDE) of 4.6-27 ng/liter, and trace amounts (less than 500 ng/liter) of
chlordane, hexachlorocyclohexane, dieldrin, and toxaphene in waters over the continental shelf
and shelf edge.
3-57
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3.2.4 Regional Geology
The regional geology characterization includes bottom topography, presence and location of large
geologic structures such as submarine canyons and seamounts, and sediment transport pathways.
3.2.4.1 Topography
The LTMS study region is located in the physiographic province called the Farallones
Escarpment. Within this province are two geomorphic areas: a northern segment where the
escarpment is about 35 km wide with a slope of six degrees and more, and a southern segment
where the width of the escarpment is about 75 km wide with a slope of about two degrees (Karl
1992). The approximate boundary between the northern and southern geomorphic areas is
37°30'N, which also separates Study Areas 2, 3, and 4 to the south from Study Area 5 to the
north.
In 1990, the United States Geological Survey (USGS) conducted a geological, geophysical, and
geotechnical study of the 3,400 km2 EPA study region ranging in depths from 200 to 3,200 m.
The regional geologic data were used to evaluate bottom stability and sediment transport, as well
as other physical and benthic processes, and to identify areas of sediment erosion, bypass, and
accumulation (Karl 1992). The regional geological setting as determined from the USGS survey
is described below.
The northern segment of the escarpment has the most rugged topographic relief. This relatively
narrow part of the escarpment is transected by numerous gullies and canyons that dissect the
slope from the shelf-slope break to the lower slope and/or basin floor. These topographic
features are oriented roughly perpendicular to the regional trend (generally northwest-to-
southeast) of the Farallones escarpment. A canyon within Study Area 5 represents one of these
slope features. Between the gullies and canyons are steep intercanyon ridges which consist of
barren rock outcrops of consolidated or hardened strata and crystalline basalt (Chin et al. 1992).
Within the gullies and canyons, unconsolidated muds have accumulated to thicknesses up to 5 m.
3-58
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Although the northern area has a rugged topography and relatively steep slopes, few examples
of massive down-slope movement could be detected from either sidescan or subbottom acoustic
records. If slump structures exist in this area, they are of small spatial dimensions and represent
only thin intervals of sediment (Chin et al. 1992).
The southern segment of the escarpment is wider than the northern segment with a mean slope
of one-third that of the northern area. The major topographic features consist of Pioneer Canyon
and Pioneer, Guide, and Mulburry Seamounts at the base of the slope. Pioneer Canyon is located
between Study Areas 3 and 4, and Pioneer Seamount is immediately west of Study Area 3.
Sidescan sonar records show that these features consist of volcanic basement rock covered with
hemipelagic (i.e., predominantly from oceanic or planktonic origins with little terrigenous
material) sediment.
The topography within both Study Area 3 and Study Area 4 is relatively featureless (Karl 1992).
Study Area 3 is located to the north of Pioneer Canyon on a gently sloping, featureless plain that
is covered by a thin and variable sediment layer. Study Area 4 is located south of Pioneer
Canyon on a gently sloping area where the sediment cover is sparse and patchy. Outcrops of
volcanic rock are present within both study areas and in Pioneer Canyon. Subbottom acoustic
profiles show a thin, discontinuous layer of unconsolidated sediment covering older sedimentary
strata or crystalline bedrock. Soft sediment is 5 to 15 m thick over the southern escarpment. The
thin layer of soft sediment makes it difficult to observe small-scale acoustic features that are
diagnostic of slumping, soft sediment deformation, and faulting.
Geotechnical analysis of sediment cores collected in both the north and south escarpment areas
showed that the upper 3 m of the sediment column appear to be physically stable under
conditions of static gravitational loading. A stability model predicted that the equilibrium
thickness for sediments deposited on a slope of one to five degrees should be 5 to 15 m thick
(Edwards et al. 1992). Subbottom profiling results from the USGS survey confirm this
prediction, as sediment cover falls within this thickness range. However, the surficial sediment
cover becomes marginally stable under conditions of seismic loading as modeled from extreme
3-59
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earthquake events. These slope stability predictions only apply to existing slope sediment, and
extrapolation or extension of these conclusions to dredged material that may be rapidly loaded
onto the ambient bottom are not warranted (Edwards et al. 1992).
3.2.4.2 Sediment Transport
Interactions of strong bottom currents and surface waves can generate bottom shear stresses that
are sufficient to suspend and initiate bedload transport of bottom sediments over the continental
shelf (Cacchione et al. 1987; Grant et al. 1984). Mass sediment movement in the form of
turbidity currents and submarine avalanches also may occur on the slope in response to
downwelling, internal waves, or earthquakes. Some downslope and offshore movement of
sediments may be indicated by results from recent EPA surveys showing onshore to offshore
gradients in sediment grain size, sediment organic content, and concentrations of some trace
sediment chemical parameters (SAIC 1992a,c).
Study Area 2
Of the four areas investigated during the EPA and Navy surveys, Study Area 2 has the greatest
potential for resuspension and transport of sediment. The bottom sediments within Study Area
2 are extensively rippled (Figure 3.2-9) indicating active bedload transport of sand. At the
shelf-slope transition (180 to 200 m) south of Pioneer Canyon, a coarser sand zone
(Figure 3.2-10) lies within a depth zone coincident with the pycnocline (water density
stratification layer) (Vercoutere et al. 1987). This may represent an area where shoaling internal
waves intersect and scour the bottom. The surface component of the California Current and
Undercurrent also can affect bottom stresses in this zone, resulting in downslope movement of
shelf sands. No low kinetic energy regions are located within Study Area 2. (The low kinetic
energy area indicated in Figure 3.2-9 likely is an artifact of high biological activity obscuring
sand ripples; SAIC 1992c). Thus, dredged material discharged at this shelf location would not
be expected to remain physically stable (i.e., non-dispersed) for any prolonged period of time.
3-60
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I
ON
0 NAUTICAL MILES 10
= Rippled/scoured bottoms
= Lower kinetic energy bottoms
Figure 3.2-9. Mapped Distribution of Ripples and Scour Lag Deposits (High Kinetic
Energy Bottoms) and Sediments Dominated by Biogenic Features (Low
Kinetic Energy Bottoms).
Source: SAIC 1992c.
-------
u>
ON
K)
0 NAUTICAL MILES 10
Figure 3.2-10. Mapped Distribution of Major Modal Grain Size (phi units).
Areas A, B, and C identify silt-clay depositional sites.
Source: SAIC 1992c.
-------
Study Areas 3 and 4
Study Areas 3 and 4 share several attributes related to sediment transport. Mapped distributions
of rippled and scoured bottoms within the shallower depths of Study Area 3 and regions
shoreward of Study Area 4 (Figure 3.2-9) appear to be affected episodically by bottom scour
related to occasional "benthic storms" (SAIC 1992c). Between these strong flow events, the
bottom may experience low kinetic energy periods when fine-grained sediments and organic
"fluff layers can accumulate until they are resuspended and transported by the next burst event.
The periodicity of these benthic storms is not known. These conclusions are based on sediment
patterns observed within depth zones of approximately 200 to 500 m which lie within areas
affected by the nearshore California Undercurrent. This current has a mean velocity of about 5
to 10 cm/sec (Vercoutere et al. 1987). However, "bursts" within this current of up to 40 cm/sec
have been measured (see Section 3.2.2). Near-bottom flow velocities of 5 to 10 cm/sec are too
weak to erode and transport large quantities of fine-grained sediments, whereas velocities over
25 cm/sec are capable of initiating bed erosion (Rhoads and Boyer 1982).
Within the depth range of 600 to 800 m, where the slope flattens from 8 to 4%, the mud (silt and
clay) content of the sediment increases from 12 to 55%. This is called the "mud line" or the mud
transition (Vercoutere et al. 1987) that generally separates nondepositional or erosional bottoms
above this depth range from more depositional regimes below this depth range. However, as
noted above, the depositional regimes below 600 to 800 m also may experience episodic
scouring.
Depositional, low kinetic sites corresponding to Alternative Sites 3 and 4 are located in Study
Areas 3 and 4 (designated as Sites "B" and "C," respectively, in Figure 3.2-10) below depths of
approximately 1,400 m. These are the only study area sites that consist of muddy sediments with
biogenic features such as fecal mounds, feeding pits, pelletal layers at the sediment-water
interface. The presence of these delicate structures is strong evidence that sediment transport is
not taking place. Thus, dredged material deposited within these two areas likely will remain
3-63
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undisturbed for relatively longer periods of time than material discharged into the shallower
portions of Study Areas 3 and 4 or within Study Area 2.
Pioneer Canyon
The Pioneer Canyon sediments have less evidence of rippling and scouring than the adjacent
portions of Study Areas 3 and 4 (Figure 3.2-9). Because Pioneer Canyon is incised into the
Farallones escarpment, it apparently is less affected by the California Undercurrent than areas at
comparable depths in Study Areas 3 and 4. The major transport direction is along the axis of
the canyon. A "pool" of mud has been mapped extending from 1,100 m to deeper than 1,400
m. This low kinetic energy area is designated as Site "A" in Figure 3.2-10.
Study Area 5
Study Area 5 contains a geological environment where sediments entering the escarpment from
the continental shelf are flushed through numerous canyons. However, sediments probably do
not accumulate over the long term until they reach the continental rise, west of Study Area 5.
The floors of gullies and canyons contain unconsolidated sediment, but these deposits may be
only temporary repositories. No unequivocal evidence of mass sediment movement within the
study area was found (SAIC 1992a). All evidence of slumping is limited to steep slopes and
walls of submarine canyons. The intercanyon ridges and sides of gullies and canyons are largely
experiencing erosion. However, a low kinetic energy (depositional) area occurs at depths
between 2,200 to 3,000 m in the trough axis and extends to the western portion of the study area
(Figure 3.2-11). The depositional area within Study Area 5 is at a slightly greater depth than
depositional areas within Study Areas 3 and 4 (corresponding to Alternative Sites 3 and 4,
respectively).
3-64
-------
123'30'W
123'28'W
123'26'W
123-24'W
123'22'W
Os
37'42'N
3740'N
37'38'N
BOUNDARY OF
LOWEST
KINETIC ENERGY
i
IfCEND
FORMER CUBA BOUNDARY
® BOX-CORE AND SEDIMENT-PROFILE IMAGE STATIONS. 1990
• SEDIMENT-PROFILE IMAGE STATIONS
Figure 3.2-11. Low Kinetic Energy Zones in LTMS Study Area 5.
Source: SAIC 1992a.
-------
3.2.5 Sediment Characteristics
Sediment characteristics considered for an ODMDS designation include grain size, mineralogy,
organic content, and chemical contaminant concentrations. In the Gulf of the Farallones, many
of these parameters show depth-related trends (e.g., SAIC 1992a,c; Booth et al. 1989) which
reflect the sources of sediments and particulate matter, transport pathways, and
erosional/depositional characteristics of the specific locations within the region.
3.2.5.1 Grain Size
Sediment grain size generally decreases with increasing depth, from predominantly sand-sized
sediments on the continental shelf to fine-grained muds on the continental slope (Figure 3.2-12).
The sand-to-sandy mud transition occurs at depths of 600 to 800 m (SAIC 1992c). Above this
transition depth, waves and the California Undercurrent scour the bottom, preferentially removing
the finer-grained sediments. At depths below this range the scouring effects are attenuated and
fine-grained sediments have longer residence times on the bottom (Vercoutere et al. 1987).
However, some localized areas of relatively coarser and relatively finer grained sediments were
observed in Study Areas 3 through 5 which reflect small-scale differences in the kinetic energy
or erosional/depositional characteristics of the specific location. Additionally, the Farallon
Islands may contribute a local source of relatively coarser sediments to adjacent areas (Hanna
1952).
The results of sediment grain size and organic content measurements from the EPA surveys are
listed in Table 3.2-5. Grain size characteristics are summarized for each of the LTMS study
areas in the following sections. The mineralogical and organic content of sediments in the study
areas are summarized in Sections 3.2.5.2 and 3.2.5.3, respectively.
3-66
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b.D
6.0
5.5
--5.0
Q.
S 4.5
03
CD
Ł 4.0
3.5
3.0
2.5
D
0
A
00
O
I
I
I
500
1,000
1,500
2,000
2,500
3,000
depth (m)
Area 2
D
AreaS
A
Area 4
O
Deep
Stations
•
Pioneer
Canyon
3,500
Figure 3.2-12. Patterns in Sediment Grain Size (mean phi) with Depth Within the LTMS
Study Region.
Symbols indicate the origins of the composite samples.
Source: SAIC 1992c.
-------
Table 3.2-5.
Descriptive Statistics for Sediment Parameters from Study Areas 2, 3, 4,
and 5.
Mean, minimum, maximum, range of values (difference between maximum and minimum),
and number of samples are shown for the study areas, deep stations (DS) west of Study Area
4, and Pioneer Canyon. All concentrations are on a dry-weight basis.
Area
All Areas
Mean
Minimum
Maximum
Range
No. Samples
Study Area 2
Mean
Minimum
Maximum
Range
No. Samples
Study Area 3
Mean
Minimum
Maximum
Range
No. Samples
Study Area 4
Mean
Minimum
Maximum
Range
No. Samples
Depth
(m)
1499
78
3060
2982
64
120
78
196
118
10
1356
550
2005
1455
19
1421
545
2010
1465
15
%TS
52.4
32.1
74.9
42.9
64
72.2
68.6
74.9
6.3
10
54.7
32.1
67.8
35.8
19
58.1
44.4
72.1
27.7
15
Avg.
Phi
4.54
3.12
5.87
2.75
63
3.63
3.48
3.87
0.39
10
4.67
156
5.42
1.86
19
4.10
3.12
4.94
1.82
14
%
Gravel
0.2
0
6.4
6.4
63
0.1
0
. 0.4
0.4
10
0
0
0.2
0.2
19
0
0
0.3
0.3
14
%
Sand
47.10
2.1
92.2
90.1
63
88.6
80.7
92.2
11.5
10
44.0
15.6
78.5
62.9
19
62.5
31.1
84.0
52.9
14
%
Silt
47.0
7.0
90.4
83.4
63
10.3
7.0
18.4
11.4
10
49.8
20.7
80.7
60.0
19
33.4
13.8
60.5
46.7
14
%
Clay
5.7
0.3
14.8
14.5
63
1.0
0.3
2.8
2.5
10
6.2
0.8
14.1
13.3
19
4.1
0.7
9.6
8.9
14
%
Carbonate
1.5
0.2
6.1
5.9
64
0.3
0.2
0.7
0.5
10
1.9
0.4
6.1
5.7
10
1.9
0.6
4.4
3.8
15
%C
1.85
0.37
3.86
3.49
63
0.43
0.37
0.55
0.18
10
1.72
0.57
3.23
2.66
18
1.33
0.66
2.58
1.92
15
%N
0.23
0.04
0.49
0.45
63
0.05
0.04
0.07
0.03
10
0.21
0.07
0.40
0.33
18
0.16
0.07
0.33
0.26
15
C/N
9.26
8.48
11.01
2.54
63
9.50
8.48
11.01
2.53
10
9.31
8.91
9.65
0.74
18
9.35
9.00
9.79
0.79
15
AK0028.W51
3-68
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Table 3.2-5.
Continued.
Area
Study Area 5*
Mean
Minimum
Maximum
Range
No. Samples
DS°
Mean
Minimum
Maximum
Range
No. Samples
Pioneer Canyon***
Mean
Minimum
Maximum
Range
No. Samples
Depth
(m)
2759
2385
3085
700
11
2604
2205
3060
855
4
1376
550
2065
1515
5
%TS
30.9
21.7
43.9
22.2
11
37.9
35.3
39.5
4.2
4
45.3
35.0
60.7
25.7
5
Avg.
Phi
5.33
3.95
5.78
1.83
11
5.32
4.80
5.87
1.07
4
4.74
4.47
5.02
0.55
5
• %
Gravel
1.2
0.3
6.4
6.1
11
0
0
0
0
4
0.1
0
0.3
0.3
5
%
Sand
13.0
2.1
37.1
35.0
11
16.1
2.1
41.3
39.2
4
32.8
19.3
47.7
28.4
5
%
Silt
76.1
48.5
90.3
41.8
11
75.4
51.7
90.4
38.7
4
60.8
47.0
69.2
22.2
5
%
Clay
'9.9
7.6
15.2
7.6
11
8.6
2.3
14.8
12.5
4
6.3
3.1
11.5
8.4
5
%
Carbonate
1.4
1.2
1.6
0.4
11
1.1
0.9
1.3
0.4
4
1.6
0.5
2.3
1.8
5
%C
3.50
2.70
3.86
1.16
11
3.13
2.63
3.77
1.14
4
2.06
0.98
2.81
1.83
5
%N
0.45
0.34
0.49
0.15
11
0.41
0.34
0.48
0.14
4
0.26
0.12
0.36
0.24
5
C/N
9.07
8.85
9.25
0.40
11
8.91
8.75
9.06
0.31
4
9.03
8.76
9.34
0.58
5
Stations 1-10, 20 (SAIC 1992a).
** Four deep stations west of Study Area 4.
*** Pioneer Canyon.
Source: SAIC (1992a,c).
AK0028.W51
3-69
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Study Area 2
Sediment grain size measurements from the EPA surveys show that sediments in Study Area 2
are primarily sandy (89%) with some silt (10%; Figure 3.2-13), a low organic carbon content
(0.4%), and low carbonate concentration relative to sediments in Study Areas 3, 4, and 5. Study
Area 2 sediments consist of relatively coarse sediments with a mean phi (negative Iog2 of particle
grain size in mm) of 3.6 and a range of 3.5 to 3.9 phi (SAIC 1992c). Study Area 2 sediments
are compact with a high total solids (TS) content (72%), which is related to the large sand
fraction. Similar sediment grain size distributions were reported from previous surveys of the
continental shelf area by Kinnetics (Parr et al. 1988), IEC (1982), and Nybakken et al. (1984).
Temporal and spatial variability in grain size are expected due to seasonal and annual differences
in current velocities, wave conditions, and variations in the input of fine-grained sediments
associated with outflow from San Francisco Bay (Parr et al. 1988).
Sand waves and ripples that likely extend throughout most of the area indicate that this is a high
energy sedimentary regime (Figure 3.2-9). Study Area 2 bottom sediments also are mixed
vertically through bioturbation by infaunal organisms. However, in spite of the high mixing by
currents and bioturbation, the sediments appear to have a high oxygen demand as no apparent
redox potential discontinuity (RPD) depth was observed at most stations located below a depth
of 80 m (SAIC 1992c). The high oxygen demand is likely related to a high flux of organic
material which is produced in the surface water layer and subsequently sinks as large organic
particles to the bottom.
Study Area 3
Sediments in Study Area 3 range from sandy sediments at the eastern edge below the shelf break
to silty sediments at the deeper western end. The average sediment composition throughout the
study area consists of 44% sand and 50% silt (Table 3.2-5). Organic matter concentrations are
quite low in the eastern part of Study Area 3, but are higher in sediments in the deeper western
end where finer-grained sediments are more prevalent. Variations in sediment composition from
3-70
-------
100
u>
JZ
D)
80
60
40
20
0
0
A
O
O
O
I
I
500
1,000
1,500
2,000
2,500
depth (m)
3,000
Area 2
D
Area 3
A
Area 4
O
Deep
Stations
•
Pioneer
Canyon
Area 5
•
Area 5
Border
*
3,500
Figure 3.2-13 Patterns in Sediment Silt Content with Depth Within the LTMS Study
Region.
Symbols indicate the origins of the composite samples.
Source: SAIC 1992c.
-------
the northern to the southern parts of the study area also are apparent; sediments along the
northern edge of are sandy, rippled, and contain lower organic carbon concentrations than the
sillier sediments that occur to the south along the same isobath. A sand outcrop occurs at about
1,400 m depth, and probably continues to the southeast through the center of Study Area 4,
crossing Study Area 4 from the northwest to the southeast. The sediment characteristics within
Study Area 3 indicate that the average kinetic energy may be intermediate between that noted
for shelf depths within Study Area 2 and that indicated for the deeper sites west of Study Area 4
and Pioneer Canyon (SAIC 1992c).
Study Area 4
Overall, Study Area 4 had the second coarsest sediments (Table 3.2-5), with an average 62.5%
sand and relatively low silt (33.4%) and organic carbon (1.3%) content. Study Area 4 was
ranked between Study Areas 2 and 3 in terms of average kinetic energy based on grain size
(SAIC 1992c). Fine-grained sediments and organic matter generally increased as depth increases.
A sandy outcrop at about 1,400 m, extending from the southeast to the northwest portion of the
study area, may be laterally correlated with a similar outcrop seen in Study Area 3. Below 1,400
m, a low kinetic energy bottom exists with sediment properties characteristic of a depositional
zone (Figure 3.2-9).
Study Area 5
Study Area 5 contains the finest sediments (Table 3.2-5) of all the study areas, including those
collected from deep sites west of Study Area 4. In addition, Study Area 5 sediments had higher
percentages of carbon and nitrogen than sediments from the other areas. Although the high mean
phi value corresponds to fine-grained sediments, some gravel sized material occurred on a knoll
just south of Study Area 5 that showed other features typical of erosional areas including a high
percentage of total solids and low carbon and nitrogen concentrations. In general, the gully area
surveyed by SAIC (1992a) in the northern Farallones Escarpment shares many features, although
on a smaller scale, with Pioneer Canyon. The characteristics of both features indicate that the
3-72
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axes of the depressions are collecting fine-grained sediments and organic matter. Results from
the USGS surveys of the area suggested that sediments accumulating in the axes of the gullies
may be temporary, and that the long-term depositional sites for sediments may be the basin floor
to the west of these features (Karl 1992). Earthquakes and/or density currents periodically may
initiate movement of accumulated sediment in a downslope direction.
3.2.5.2 Mineralogy
The clay mineralogy of the continental shelf sediments off California was described by Griggs
and Hein (1980). Booth et al. (1989) reported trends with depth in mineralogical patterns; in
general, the quantity of clay minerals increased while the nonclay minerals—primarily feldspar,
quartz, and heavy minerals (amphibole)—decreased with depth. Smectite is the predominant clay
mineral in the continental shelf sediments, with lesser amounts of chlorite, kaolinite, and illite.
Booth et al. (1989) suggested that there is a similarity between the clay mineral assemblage from
the low-level radioactive waste sites and that of the Russian River sediments. This observation
strongly suggests that sediment input to the Gulf slope regions is from areas to the north.
Vercoutere et al. (1987) described the mineralogical attributes of sediments in the portion of
Study Areas 2, 3, and 4 at depths less than 1,200 m. However, mineralogical data for the low
kinetic energy depositional areas at depths below 1,400 m (including depositional Sites "A" in
Pioneer Canyon, "B" in Study Area 3, and "C" in Study Area 4) are not included in their study.
Sediment characteristics at depths corresponding to the core of the OMZ (500 to 900 m) appear
to be different from those of the upper and lower edges of the OMZ. The upper boundary has
abundant glauconite and foraminiferal carbonate, whereas the lower boundary has abundant fecal
pellets, high mica content, high foraminiferal carbonate, low concentrations of quartz and
feldspar, and no glauconite. The core of the OMZ has an increased content of mica, lower
carbonate, and a higher relative percentage of quartz and feldspar; glauconite and fecal pellets
are only minor components (Vercoutere et al. 1987).
3-73
-------
Sediment mineralogical data are available for Study Area 5 (SAIC 1992a). All sediments
contained high organic carbon concentrations (2.7 to 3.8% by wt.), reflecting high productivity
of the overlying water. This high surface productivity also is reflected in biogenic carbonate
which is contributed mainly by coccolithophores (1 to 2% by wt.); no foraminifera were
observed. Biogenic opal also is present in the form of diatom frustules. The bulk of the
minerals is contributed by clay (phyllosilicate) minerals, dominated by illite and chlorite.
Smectite and kaolinite are present but less common. Clays range from 24 to 73% of the total
minerals present. Quartz is the next most abundant mineral (20 to 36% of total minerals), and
feldspar ranges from 6 to 52% of total minerals (SAIC 1992a).
3.2.5.3 Sediment Organic Content
Concentrations of organic carbon and organic nitrogen in sediments from the study areas are
presented in Table 3.2.5). In general, the concentrations of organic carbon and nitrogen increase
with increasing depth (Figure 3.2-14) and with decreasing grain size (i.e., higher phi,
Figure 3.2-12). As discussed above for the individual study areas, these trends also are correlated
with regional trends in the fine fractions of sediments. Trends in the organic content of the
sediments may influence the spatial trends of concentrations of trace metals and trace organic
contaminants (Sections 3.2.5.4 and 3.2.5.5). Positive correlations between inventories of metals,
organic matter, and grain size are well known (Forstner and Wittman 1983).
3.2.5.4 Sediment Trace Metals
Concentrations of the selected sediment trace metals measured during the EPA and Navy surveys
of Study Areas 2, 3, 4, and 5, and Pioneer Canyon (SAIC 1992a,c) are summarized in
Table 3.2-6. For comparison, data for sediments from San Francisco Bay and NS&T Program
sites, for deep-sea sediments (primarily clay and carbonate sediments) and for local bedrock are
presented in Table 3.2-7. The local bedrock of the Franciscan Complex, which consists of basalts
and shales, is a likely source of sediments to the offshore region (Yamamoto 1987; Murray et
al. 1991) and, therefore, represents the natural or background concentrations of sediment metals.
3-74
-------
5.0
4.0
D)
"CD
3.0
2.0
T3
o^
C
O
JD
81.0
0.0
0
*
A
500
1,000 1,500 2,000
depth (m)
2,500
3,000
Area 2
D
Area3
A
Area 4
O
Deep
Stations
•
Pioneer
Canyon
Area 5
•
Area 5
Border
*
3,500
Figure 3.2-14. Patterns in Sediment Total Organic Carbon Concentrations with Depth
Within the LTMS Study Region.
Symbols indicate the origins of the composite samples.
Source: SAIC 1992a,c.
-------
Table 3.2-6.
Trace Metal Concentrations in Sediments for Study Areas 2, 3, 4,
and 5, and Pioneer Canyon.
Metal concentrations are in ppm (dry weight) except for aluminum (Al) which is in
percent (dry weight). Range is the differences between the maximum and minimum
values.
Area
Study Area 2
Mean
Minimum
Maximum
Range
No. Samples
Study Area 3
Mean
Minimum
Maximum
Range
No. Samples
Study Area 4
Mean
Minimum
Maximum
Range
No. Samples
Study Area 5
Mean
Minimum
Maximum
Range
No. Samples
Ag
0.115
0.101
0.129
0.028
2
0.518
0.191
0.687
0.496
5
0.403
0.250
0.526
0.276
4
0.55
0.45
0.64
0.19
4
Al
6.83
6.77
6.89
0.12
2
6.47
6.17
6.83
0.66
5
5.92
4.85
6.72
1.87
4
6.67
5.90
7.61
1.71
13
Cd
0.854
0.829
0.878
0.049
2
0.373
0.172
0.770
0.598
5
0.188
0.144
0.284
0.140
4
0.31
0.24
0.38
0.14
4
Cr
189
141
236
95
2
168
156
173
17
5
162
117
185
68
4
149
127
168
41
13
Cu
11.7
11.6
11.7
0.1
2
24.3
15.8
34.1
18.3
5
27.4
17.3
42.6
25.3
4
41.9
19.8
62.5
42.7
13
Hg
0.04
0.03
0.04
0.01
2
0.08
0.05
0.12
0.07
5
0.06
<0.01
0.12
0.12
4
0.20
0.13
0.36
0.23
11
Ni
54.5
54.4
54.5
0.1
2
66.3
61.0
73
12.0
5
65.1
54.1
75.7
21.6
4
92.2
77.0
115.0
38.0
13
Pb
15.7
15.6
15.7
0.1
2
13.8
12.1
14.8
2.7
5
15.1
10.3
24.9
14.6
4
10.4
9.6
12.0^
2.4
4
AK0029.W5I
3-76
-------
Table 3.2-6.
Continued.
Area
Pioneer Canyon
Mean
Minimum
Maximum
Range
No. Samples
Ag
0.713
0.186
1.070
0.884
5
Al
6.62
6.24
7.01
0.77
5
Cd
0.462
0.185
1.060
0.875
5
Cr
151
143
164
21
5
Cu
28.1
15.8
38.3
22.5
5
Hg
0.06
<0.01
0.10
0.10
5
Ni
71.1
55.7
85.5
29.8
5
Pb
12.5
12.0
13.1
1.1
5
Source: SAIC (1992a,c).
AK0029.W51
3-77
-------
Table 3.2-7.
Trace Metals in Sediments from the Study Areas and Comparison Data.
Metals (ppm dry wt):
Aluminum (%)
Cadmium
Chromium
Copper
Lead
Mercury
Nickel
Silver
Study Areas 2> 3f and 4*
Mean
6.42
0.41
164
24.7
13.9
0.06
66.0
0.50
Range
4.85-7.01
0.14-1.06
117-236
11.6-42.6
10.3-24.9
< 0.01-0.12
54.1-85.5
0.10-1.07
NOAA NS&T Program2
San Francisco Bay Sites
Fine Seds
(> 20% with phi > 4.0)
Mean
(NA)
0.42
425
69.4
40.8
0.32
151.6
0.5
Range
(NA)
0.18-0.81
185-1,587
49.9-93.7
21.4-84.9
0.03-0.54
103.4-252.1
0.08-0.87
Coarse Se20%witn
phi < 4.0)
(NA)
0.28
259
13.7
5.2
0.05
72.1
0.44
AIIU.S.
Sites
Range
(NA)
0.01-11.3
5.2-3,374
0.4-319
0.9-280
0.007-4.31
1-252
: 0.01 -11. 6
Deep-Sea Sediments9
Clay
8.40
0.42
90
250
80
(NA)
225
0.11
Carbonate
2.00
(NA)
11
30
9
(NA)
30
(NA)
Average Franciscan
Complex*
Chert
1.4
(NA)
9.5
(NA)
25
(NA)
16
(NA)
Shale
12.2
(NA)
90
(NA)
78
(NA)
70
(NA)
u>
00
'Data are from 16 composite samples (SAIC 1992c). '
2NOAA(1988). •
^Turekian and Wedepohl (1961).
4Data from the Franciscan Complex (Central belt) in Sausalito (CA), 1.5 km north of the Golden Gate Bridge are from Yamamoto (1987).
NA = not available
AK0030.W51
-------
The concentrations of aluminum, cadmium, copper, lead, and nickel in sediments from the study
areas are comparable to those in deep-sea sediments and to the Franciscan Complex. In contrast,
concentrations for chromium and silver are higher in samples from the study areas. Comparative
data for silver and mercury concentrations in deep-sea sediments or the Franciscan Complex are
limited. However, measured concentrations of these metals generally are comparable to those
reported in sediments from other coastal areas (e.g., Bruland et al. 1974). Nevertheless, mean
concentrations of chromium, copper, lead, mercury and nickel in sediments from the study areas
are lower than those in sediments in San Francisco Bay as measured in the NS&T Program.
Trends in concentrations of trace metals with water depth are illustrated in Figure 3.2-15. Values
represent the composite sediment samples and the average depth of the locations sampled for
each composite sample during the EPA and Navy surveys. In general, concentrations of copper,
mercury, nickel, and silver increase with depth over the study region (Figure 3.2-15D). These
trends also follow the trends for decreasing TS content and increasing organic carbon and
nitrogen concentrations and decreasing sediment grain size. In contrast, cadmium concentrations
decrease with increasing depth (Figure 3.2-15B), whereas, distinct trends with depth are not
apparent for aluminum, chromium, and lead (Figure 3.2-15A,C).
The association of relatively higher concentrations of metals in sediments with finer grain size
has been reported from other geographic regions (Forstner and Wittman 1983). The observed
differences between study areas in the sediment trace metal concentrations generally are
consistent with spatial patterns of sediment grain size and organic content. There is no evidence
of elevated sediment metals concentrations (i.e., unsupported by higher percentages of
fine-grained sediments) indicative of significant anthropogenic contaminations over the study
region.
3-79
-------
aluminum
IU
H* 8
O)
'o
"O
"o
A
E 4
3
C
E
-2 2
CO
n
•
—
** *
DD i * ^" A • * ***
o
0
• /•
Area g ('91)
Area^(91)
Area ^('91)
Pioneer
Canvon
Aro^i ^ /'Q1\
/\iod v \ v i ^
Area 5 ('91)
Border
Area Ł('90)
•
_
•
M «
A
i i i i i i i
500 1.000 1,500 2,000
depth (m)
2,500
3,000
3,500
Figure 3.2-15.
cadmium
\.t
— , 1-0
O)
'CD
§ 0.8
•o
Ens
Q.
a.
E
3 0.4
E
"O
CO
°0.2
n n
•
-
"D
D
A
Area 2 ('91)
Area Ł('91)
Area Ł('91)
Pioneer
Canvon
Area | ('90)
-
-
-
-
A A" •
O •
0 A0"AB
B
i i i i i i t
500 1,000 1,500 2,000
depth (m)
2.500
3,000
3,500
Sediment Concentrations of: (A) Aluminum; (B) Cadmium;
(C) Chromium, and (D) Copper Within the LTMS Study Region.
Symbols indicate the origins of the composite samples.
Source: SAIC 1992a,c.
AK0084
p. 1 of 2
3-80
-------
chromium
ouu
.--.250
0)
'CD
5 200
0.150
-B
E
P 100
E
o
.c
o 50
n
-
D
0 0
A A A A j* *
n • • B J^ * *A
o
— 0 00 0
Area g ('91)
AreaŁ('91)
Area Ł ('91)
Pioneer
Canvon
AreaŁ('91)
Area 5 ('91)
Border
Area 5 ('90)
•
-
-
.
-
"
-
-
•
-
i i i i i i i
500 1,000 1,500 2.000
depth (m)
2,500
3,000
3,500
copper
60
^•50
O)
'CD
5 40
•o
Ł
a. 30
" —
CD
0.20
Q.
O
O
10
n
*
•A A
• *
* *
0 i
A A
• • *
•
• o
Area g ('91)
AreaŁ('91)
Area Ł('91)
Pioneer
Canvon
AreaŁ('91)
Area 5 ('91)
Border
Area 5 ('90)
9
-
•
-
„
—
-
-
- ^ —
oA
ft
-DD
i i i i i i i
500 1,000 1,500 2,000
depth (m)
2,500
3,000
3,500
Figure 3.2-15. Continued.
AK0084
p. 2 0(2
3-81
-------
Study Area 2
Sediments from Study Area 2 generally contained high concentrations of cadmium and
chromium, but lower concentrations of silver and copper, compared to those in the other study
areas (Table 3.2-6). The mean cadmium concentration (0.854 ppm) is approximately two to five
times higher than mean concentrations for the other study areas, but comparable to concentrations
measured in shelf sediments by Nybakken et al. (1984) and to concentrations in sediments at
similar depths in a relatively pristine area of the Santa Maria Basin, California (Steinhauer et al.
1991). The chromium concentration (mean=189 ppm) was somewhat higher than average
concentrations for Santa Maria Basin sediments (45-102 ppm; Steinhauer et al. 1991) and
concentrations in local source rocks (Table 3.2-7). It is possible that enriched chromium
concentrations in the study area sediments are from weathering of bedrock sources containing
chromite minerals. Although the mean silver (0.115 ppm) and copper (11.7 ppm) concentrations
were relatively low, they were similar to average concentrations in Santa Maria Basin sediments
(0.15 and 13 ppm, respectively).
Concentrations of chromium, copper, lead, and mercury measured in shelf sediments by
Nybakken et al. (1984) were up to several times lower than those measured in the Study Areas 2
sediments during the EPA surveys. The relatively lower concentrations reported by Nybakken
et al. likely were due to differences in analytical methodologies (sediment digestion procedures)
rather than to spatial or temporal changes.
Study Area 3
Concentrations of cadmium in Study Area 3 sediments were lower than those at Study Area 2
and decreased with increasing depth. The concentrations generally were greater than those at
Study Area 4, except at depths greater than 1,500 m (region of Alternative Sites 3 and 4), where
the concentrations were comparable. All measured cadmium concentrations are less than those
found in southern California slope sediments (1.45 ppm) and average deep-sea clays
3-82
-------
(Table 3.2-7). Chromium concentrations were relatively uniform but somewhat high (mean=168
ppm). The average silver concentration in Study Area 3 was 0.518 ppm, which is greater than
that found in typical southern California slope or shelf sediments, crustal rocks, average shales,
and deep-sea clays and carbonates. Concentrations increased with depth to a maximum of
approximately 0.7 ppm. The average copper concentration in the study area was 24.3 ppm,
which is intermediate to those of the southern California slope (31 ppm) and continental shelf
(13 ppm). While the higher copper concentrations occur in deeper water, the range of
concentrations in Study Area 3 falls within the values cited above for other California slope and
shelf regions.
Study Area 4
The cadmium concentrations in Study Area 4 generally were low and uniform with few
exceptions. Concentrations for all other metals were similar to those in Study Area 3.
Pioneer Canyon
Pioneer Canyon sediments contained higher silver concentrations (mean=0.713 ppm) than any of
the study areas. The source of the silver, above natural background concentrations, is unknown.
Other trace metal concentrations generally were similar to those in Study Area 3.
Study Area 5
Concentrations of silver, chromium, lead, and aluminum in Study Area 5 were similar to those
at Study Areas 3 and 4. Cadmium concentrations are similar to those at Study Area 3.
Concentrations of copper (mean=41.9 ppm), mercury (mean=0.20 ppm), and nickel
(mean=92.2 ppm) were higher than those from the other study areas.
Although some differences between the study areas in the concentrations of individual trace
metals were apparent, the trends are well correlated to differences in sediment grain size and
3-83
-------
organic content. The magnitudes of the concentrations of individual metals generally are
comparable to expected natural or background levels. With the possible exception of silver
concentrations in Pioneer Canyon sediments and mercury concentration in the Study Area 5
sediments, there is no strong evidence of unusually high or enriched trace metal concentrations
suggestive of contamination from historical waste disposal operations or other anthropogenic
sources.
3.2.5.5 Sediment Hydrocarbons
Hydrocarbons in sediments include a variety of organic compound classes such as
non-chlorinated aliphatics (i.e., saturates), non-chlorinated aromatics, chlorinated pesticides, and
PCBs. Many aliphatic and aromatic hydrocarbons may be derived from a variety of natural (e.g.,
oil seeps), anthropogenic, and biogenic sources. For example, saturated and aromatic
hydrocarbons are principal components in residues of both crude and refined petroleum products.
In addition to direct inputs from spills of petroleum products and diagenetic sources (i.e., in situ
processes associated with marine sediments such as submarine oil seeps), inputs to marine
sediments of aliphatic and aromatic compounds of oil-related origin can result from atmospheric
fallout of combustion products. Certain hydrocarbons are produced naturally by marine as well
as terrestrial biota, although the variety of biogenic compounds is limited relative to oil-derived
hydrocarbons. The general composition of these biogenic hydrocarbons is quite different from
oil-derived hydrocarbons and these differences can be utilized to distinguish between sources of
hydrocarbons. For example, n-alkanes in oil have approximately equal concentrations of
compounds with odd and even numbers of carbon atoms (i.e., an odd to even ratio of
approximately 1). In contrast, biologically-produced n-alkanes have a predominance of n-alkanes
with odd numbers of carbon atoms (i.e., odd to even ratio substantially greater than 1).
Consequently, the overall composition of hydrocarbon classes such as n-alkanes can be used to
identify the generic source of compounds in sediment samples.
Concentrations of total n-alkanes and PAHs in sediments from the LTMS study areas are
summarized in Table 3.2-8 and shown in Figure 3.2-16. The values in the figure are from the
3-84
-------
Table 3.2-8.
Hydrocarbon Concentrations in Sediments for Study Areas 2,3, and 4,
and Pioneer Canyon.
Hydrocarbon concentrations are in ppb (dry weight) except for the Unresolved Complex
Mixture which is in ppm (dry weight). Range is the difference between the maximum and
minimum values.
Area
Study Area 2
Mean
Minimum
Maximum
Range
No. Samples
Study Area 3
Mean
Minimum
Maximum
Range
No. Samples
Study Area 4
Mean
Minimum
Maximum
Range
No. Samples
Pioneer Canyon
Mean
Minimum
Maximum
Range
No. Samples
Aliphatic
Hydrocarbons
Alkanes
414
414
414
0.1
2
1,200
752
1,440
691.2
5
1,300
704.5
2,060
1,360
4
1,745
964
2,290
1,320
5
Polynuclear
Aromatic
Hydrocarbons
127
123
131
8.21
2
317
211
390
180
5
349
200
585
385
4
446
257
610
353
5
Unresolved
Complex Mixture
1.2
1.1
1.3
0.2
2
4.9
3.6
6.3
2.7
5
6.3
2.4
13.3
10.9
4
10.1
5.0
16.1
11.1
5
Total
Pesticides
1.61
1.50
1.71
0.21
2
3.81
2.34
4.51
2.17
5
3.40
2.14
4.84
2.70
4
4.61
2.20
5.98
3.78
5
Total PCBs*
15.0
14.8
15.1
0.03
2
28.4
15.5
68.1
52.6
5
18.8
14.8
23.1
8.3
4
18.8
15.7
21.4
5.7
5
'The method detection limit for total PCB concentrations is approximately 20 ppb; values below 20 ppb should be considered estimates.
Source: SAIC (1992c)
AK0031.W51
3-85
-------
Ł
05 2,000
0)
^
2 1'500
a.
a.
V)
c 1,000
CO
"co
i
c
]S 50°
o
A
. Area 2
Areas •
_ ti _
Area 4 • O
• Pioneer B
Canvon
• A A o A
A 0
•
O
-
an
A
i i i i
0 500 1,000 1,500 2,000 2,500
depth (m)
600
^500
Ł
O)
'<*> *™
5 400
T3
•g.300
n:
<200
O
"" 100
n
^
-
Area 2 O •
Areas
Area 4
C»
Pioneer
Canvon • .
;
• A °
A O
n
•
B
500
1,000 1,500
depth (m)
2,000
2,500
Figure 3.2-16. Sediment Concentrations of: (A) Total n-alkanes and (B) Total PAHs
Within the LTMS Study Region.
Symbols indicate the origin of the composite samples.
Source: SAIC 1992c.
AK0085
3-86
-------
sixteen composite samples from Study Areas 2, 3, and 4, and from Pioneer Canyon.
Concentrations of both n-alkanes and PAHs generally increase with increasing depth in the study
areas. As noted, total organic carbon also increases with depth throughout the study areas
(Figure 3.2-14). Figure 3.2-17 shows concentrations for total n-alkanes and PAHs in the
individual composites and the corresponding concentrations of total organic carbon, and indicates
a close correspondence between these parameters. Consequently, the levels of total n-alkanes and
PAHs in sediment samples from the study areas appear to be related to transport processes that
also affect the overall organic content of sediments in the study areas. Similar correlations
between concentrations for total hydrocarbons and organic carbon content have been reported in
surface sediments from the Gulf of Mexico (Boehm 1987).
Chlorinated pesticides and PCBs are synthetic compounds that are not native to the marine
environment. These classes of compounds can derive from surface runoff, aerial fallout, and
disposal of contaminated wastes. Concentrations of total chlorinated pesticides and total PCBs
are summarized in Table 3.2-8, and concentrations of total DDT and total PCBs are plotted in
Figure 3.2-18.
Study Areas 2, 3, and 4
Summaries of the concentrations of organic compounds in sediments from Study Areas 2, 3, and
4, and from Pioneer Canyon, are presented in Table 3.2-8. Study Area 3 had two to three times
the concentration of organic compounds as Study Area 2. However, except for pesticides and
total PCBs, the mean concentrations of other hydrocarbons were less than those in Study Area
4 or in Pioneer Canyon. Except for total PCBs, the concentrations of all organic compounds
were highest in the Pioneer Canyon, which probably reflects depositional focusing and transport
of sediments at this location.
Although samples from the study areas were analyzed for a variety of chlorinated pesticides,
detectable quantities of individual pesticides were measured routinely for only DDT analogs and
isomers (particularly 4,4'-DDE, 4,4'-DDD, and 2,4'-DDE); other chlorinated pesticides were not
3-87
-------
total n-alkanes and organic carbon
2,500
8 9 10 11 12 13 14 15 16
total
n-alkanes
organic
carbon
total PAH and organic carbon
600
500
400
5
TJ
•a. 3oo
a.
1
I200
100
8 9 10 11 12 13 14 15 16
3.0
2.5
2.0
1.5
total
PAH
organic
carbon
0)
'
-------
total DDT
?5
D)
'(D
Q.
,0.
1-3
Q
Q
02
AreaS
Area 4
Pioneer
Canyon
O
A
500
1,000 1,500
depth (m)
2,000
2,500
80
70
Ł•
50
JD
Q.
^40
CO
o
^30
OJ
*-«
O
~ 20
10
AreaS
Arecf4
Pioneer
Canyon
500
total PCB
A
O
1,000 1,500
depth (m)
2,000
2,500
Figure 3.2-18. Sediment Concentrations of Total DDT and Total PCBs Within the LTMS
Study Regions.
Symbols indicate the origins of the composite samples.
Source: SAIC 1992c.
AK0087
3-89
-------
detected in the sediments. Individual PCBs (congeners) were detected in the sediments, but at
concentrations typically at or near the analytical detection limits. Plots of concentrations for total
DDT and total PCBs for the composite samples are presented in Figure 3.2-18. Concentrations
of total DDT generally increase with depth along with the organic content of the sediments.
These trends indicate that DDT concentrations also are related to transport processes affecting
the overall organic content of sediments in the study areas.
Concentrations of total PCBs typically were at or below the analytical detection limits, with the
exception of measurable amounts of PCBs in sediments composited from three stations along the
1,000 m isobath in the northern portion of Study Area 3. Consequently, the sediment PCB
concentrations appear to be relatively uniform throughout the study areas, and no correlation
between PCB concentrations and organic carbon content is evident. The relatively elevated
concentration for PCBs in the single composite sample from Study Area 3 presumably reflects
a localized input of PCBs to the area.
Study Area 5
Hydrocarbons and other trace organic contaminants were not detected (i.e., less than the
analytical detection limits) in sediments collected in Study Area 5 during the Navy surveys
(SAIC 1992a). However, these samples were analyzed using different methods, with lower
analytical sensitivity (i.e., higher detection limits), than those used for sediments from Study
Areas 2, 3, and 4. Also, the concentrations of n-alkanes and many of the PAHs were not
analyzed in Study Area 5 sediments. Only the PCB Aroclor 1221 was present in concentrations
near the detection limit. The pesticide Lindane (=Gamma-BHC) also was detected in Study Area
5 sediments; whereas, this compound was not found in any of the samples from Areas 2, 3, 4,
and the Pioneer Canyon.
Regional Summary
In general, a trend in increasing concentrations of hydrocarbon compounds with depth over the
study region is apparent. This relationship likely is not related to historical waste discharges or
3-90
-------
proximity to source inputs. Rather, the magnitudes, composition, and spatial distributions reflect
correlations between sediment hydrocarbons, fine grain size, and higher organic contents as
observed in other marine environments.
Hydrocarbon data for sediments from San Francisco Bay and sites from the NS&T Program are
summarized in Table 3.2-9 Concentrations of hydrocarbons in sediments from the study areas
generally are lower than concentrations in San Francisco Bay sediments, although both
substantially lower and higher concentrations for the PAHs, DDT, and PCBs occur in coastal
sediments from other locations throughout the U.S.
Previous measurements of sediment hydrocarbons within the region indicated trace concentrations
of DDE (2.1-3.2 ng/g), DDD (up to 0.1 ng/g), and chlordane (2.2-2.8 ng/g) in sediments at the
100-Fathom site; PCBs were not detected (IEC 1982). Nybakken et al. (1984) reported similar
concentrations of DDE (0.2-1.6 ng/g), along with trace quantities of PCBs (0.2-0.5 ng/g), alpha-
and gamma-chlordanes (0.01-0.6 ng/g), and selected PAHs (1-74 ng/g phenanthrene, 1-49 ng/g
fluoranthene, and 1-56 ng/g pyrene) in sediments from the continental shelf and shelf edge. The
PAHs probably are derived primarily from particle discharges from San Francisco Bay and
atmospheric deposition of combustion-derived products.
Melzian et al. (1987) reported relatively high concentrations of chlorinated hydrocarbons (DDT
and PCBs) in the liver tissues of Dover sole (Microstomas pacificus) and sablefish (Anoplopoma
fimbrid) collected at depths of 500 m and 1,000 m in the vicinities of the former low-level
radioactive and chemical munitions disposal sites. Although the source(s) of the chlorinated
organics in the fish liver tissues could not be discerned, Melzian et al. suggested that historical
wastes may represent a source for one or more of these contaminants.
However, with the exception of the relatively elevated concentration of total PCBs in the one
composite sample from Study Area 3, there was no evidence from the EPA surveys of significant
anthropogenic sediment contamination within the LTMS study areas.
3-91
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Table 3.2-9.
Hydrocarbons in Sediments from the Study Areas and Comparison
Data.
Organics {ppb (fry wt):
Total PAH
Total DDT
Total PCB
Study Areas 2, 3, and 41
Mean
318
3.42
21.3
Range
111-572
1.40-5.54
14.8-68.1
NOAA NS&T Program2
San Francisco Bay Sites
FtneSeds
{> 20% with phi > 4.0)
Mean
2,166
15.8
62.6
Range
491-5,230
3.0-44.9
33.3-82.8
Coarse Seds
(> 20% with
phi < 4.0)
799
0.33
10.5
All U.S.
Sites
Flange
2-57,800
0.04-6,891
0.3-2,069
'Data are from 16 composite samples (SAIC 1992c).
2NOAA (1988).
AK0032.W51
3-92
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3.2.5.6 Sediment Radionuclides
As discussed in Section 3.1, low-level radioactive wastes were disposed historically at several
locations within the Gulf of the Farallones. Several studies (PneumoDynamics 1961; Dyer 1976;
Noshkin et al. 1978; Shell and Sugai 1980; Suchanek and Lagunas-Solar 1991) have been
conducted to determine whether the historical discharges have resulted in elevated radionuclide
concentrations in waters, sediments, or organism tissues. NOAA (1990) estimated that studies
conducted between 1960 and 1977 have collected over 900 water samples, 30 sediment cores,
and 400 biota samples, primarily near disposal sites A, B, and C (see Table 3.1-3).
Detectable amounts of several radionuclides, primarily cesium-137 (137Cs) and plutonium-239/240
(239t240Pu), have been measured in the water, sediment, and tissue samples. However, the
significance of the measured concentrations, and the contributions to the total concentrations of
the waste material relative to inputs from nuclear fallout, are equivocal. For example, Dyer
(1976) concluded that the measured concentrations of 239+240Pu in sediments near a waste canister
cluster were from 2 to 25 times higher than background levels. Suchanek and Lagunas-Solar
(1991) calculated that the concentrations measured by Dyer actually were up to 1,064 times
above background. Noshkin et al. (1978) questioned the reference or background levels used by
Dyer and concluded that the total 239+240pu inventory in the Gulf of the Farallones (2.1-3.5
mCi/km2) is not significantly different from fallout levels in the open Pacific ocean (2.2-4.3
mCi/km2). Shell and Sugai (1980) also collected sediments hear ruptured drums which contained
measured quantities (9-137 pCi/kg) of 239+240Pu. They concluded that the sediment plutonium
concentrations at this site were from 2 to 200 times higher than levels expected from fallout
sources alone.
Therefore, while the presence of ruptured drums containing low-level radioactive wastes in the
Gulf of the Farallones has been well-documented, the contributions of these wastes to the
measured sediment radionuclide concentrations, the spatial extent of any contamination, and the
environmental impacts and potential human health risks associated with the wastes are
3-93
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problematic. NOAA and EPA presently are evaluating these questions to assess the need for
remediation.
3.3 Biological Environment
3.3.1 Plankton Community
This section presents information on plankton and their distributions and abundance in the general
vicinity of LTMS Study Areas 2, 3, 4, and 5.
Plankton are free-floating organisms that typically drift with ocean currents, in contrast to
actively swimming species such as fish. In general, plankton can be divided into three broad
categories: prokaryotic bacterioplankton; phytoplankton, representing single-celled plants that
are capable of photosynthesis and which form an important base for many marine systems; and
zooplankton, representing animals that are a primary link in many food webs between
phytoplankton and larger marine organisms such as fish, sea birds, and marine mammals.
Zooplankton includes animals that remain planktonic throughout their life (holoplankton) as well
as larval stages of benthic invertebrates (meroplankton) and fish (ichthyoplankton). Plankton
distributions are characterized by high spatial patchiness, strong seasonal and inter-annual
variation, and direct responses to oceanic circulation (McGowan and Miller 1980). The basic
circulation pattern along the central California coast consists of the southward-flowing California
surface current and the northward-flowing California Undercurrent, which often becomes a
surface current during winter (Noble and Ramp 1992; Hayward and Mantyla 1990). This general
pattern for coastal circulation can be modified by local topography and wind fields, and can
change considerably on time scales of a few days (Breaker and Mooers 1986).
Satellite imagery indicates that the Gulf of the Farallones is an area of high planktonic activity,
due to the combination of seasonal upwelling characteristic of the entire California coast (Barber
and Smith 1981), local effects of nutrient inputs from San Francisco Bay (KLI 1991), and such
features as the Point Reyes coastal upwelling jet (Noble and Ramp 1992). Detailed information
3-94
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on seasonal patterns of production, abundance, and species composition for the LTMS study areas
is not available; however, a general description of the plankton community can be summarized
from studies along the central California coast. Bence et al. (1992) present a study area-specific
review of plankton data available from NMFS, CDFG and CalCOFI research, and from CalCOFI
plankton atlases. The NMFS data focus on midwater trawl surveys and one ichthyoplankton
survey. The CDFG data consist of zooplankton samples collected between 1975 and 1980 during
a study of Dungeness crabs (Cancer magister). The CalCOFI data emphasizes ichthyoplankton
counts and plankton volume.
3.3.1.1 Phvtoplankton
The predominant members of the phytoplankton community are diatoms, silicoflagellates,
coccolithophores (Chrysophyta), and dinoflagellates (Pyrrophyta). Three parameters commonly
used to describe phytoplankton communities are the following: (1) productivity, reflecting the
amount of new plant material formed per unit of time; (2) standing crop, representing the amount
of plant material present, usually expressed as concentrations of chlorophyll or cell number; and
(3) species composition. Inter-annual variation and seasonal cycles of productivity and standing
crop reflect variations in the upwelling regime along the central and northern coast of California,
including the general study areas for this program. During the upwelling season, phytoplankton
blooms in northern California generally occur between March and August (Welch 1967). Diatom
growth is sparse in years of weak upwelling, while intermittent upwelling stimulates diatom
growth (Bolin and Abbott 1963).
The combination of seasonal coastal upwelling events and nutrient inputs from San Francisco Bay
promotes high primary productivity throughout the study area (KLI1991). CalCOFI data indicate
that both chlorophyll a and phaeopigments are highest in continental shelf waters, which suggests
that standing stocks of phytoplankton are higher in nearshore areas (e.g., water depths similar to
Study Area 2 and the shallow portion of Study Area 3) than in offshore regions (Bence et al.
1992). Highest productivity levels between Point Sur and the Gulf of the Farallones occur within
approximately 50 km of the coast (Owen 1974). Average productivity values in the latter study
3-95
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ranged from 342 to 586 mg carbon/m2/day over the course of a year. The maximum productivity
(1,300 mg carbon/m2/day) was reported for a site within 50 km of the Golden Gate during
August-September. The minimum productivity (256 mg carbon/m2/day) was observed during
a May-June cruise.
Standing crop lagged behind the cycle of productivity by about two months. Surface chlorophyll
concentrations ranged from less than 0.5 mg/m3 during July-September to 2-8 mg/m3 during
October-December (Owen 1974). Although Garrison (1976) reported similar values from waters
near the mouth of Monterey Bay, Ambler et al. (1985) measured chlorophyll concentrations
ranging from less than 1 mg/m3 between October and January to nearly 5 mg/m3 in April and
June. Differences in measurements of chlorophyll concentrations among studies may be related
to the time lag required for phytoplankton growth (Abbott and Zion 1985). Phytoplankton
initially respond to nutrient input with increased primary production, leading to increased
population size after a time lag, resulting in a dynamic biological structure (Denman and Abbott
1988).
Species composition of phytoplankton communities also varies seasonally. The spring/summer
phytoplankton bloom, coincident with upwelling events, is dominated by diatoms, specifically
species of Chaetoceros and Rhizosolenia. During non-upwelling periods, dinoflagellates of the
genera Ceratium and Peridinium dominate (Bolin and Abbott 1963; Welch 1967). A similar
seasonal pattern of species composition was observed along the central coast (Malone 1971) and
approximately 200 km south of the study area near Diablo Canyon (Icanberry and Warrick 1978).
In summary, several studies on phytoplankton along the central California coast indicate seasonal
cycles of productivity, standing crop, and species composition. It is anticipated that
phytoplankton within the LTMS study areas will exhibit the same general cycles, although factors
such as upwelling, the complex topography of the Gulf of the Farallones, and nutrient inputs
from San Francisco Bay may have significant localized effects. Productivity and standing crop
appear to be highest in continental shelf waters including Study Area 2 and the shallow portion
3-96
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of Study Area 3. Potential impacts to phytoplankton communities from dredged material disposal
activities are expected to be temporary (Section 4.4).
3.3.1.2 Zooplankton
An estimated 546 invertebrate zooplankton species and approximately 1,000 ichthyoplankton
species occur in the California Current system (Kramer and Smith 1972). Copepods and
euphausiids, an important food source for many organisms, including juvenile fish, dominate the
holoplankton in terms of numbers and biomass, although thalacians (salps), chaetognaths (arrow
worms), and pelagic molluscs also are abundant (Table 3.3.1-1). Common species in the
California Current include the euphausiid Euphausia pacifica, copepods of genera Calanus,
Neocalanus, Eucalanus, and Acartia, and salps. Based on CalCOFI data, Bence et al. (1992)
classified 34 holoplankton species that are common to the California Current into nearshore or
offshore distribution categories (Table 3.3.1-1). Various species of copepods, euphausiids, and
chaetognaths were found in both nearshore and offshore waters, whereas thaliaceans and pelagic
molluscs occurred primarily offshore.
The CalCOFI summary was supplemented by results of zooplankton studies conducted by
Hatfield (1983) and Tasto et al. (1981). These latter samples were collected as part of a CDFG
study on Dungeness crabs. Hatfield identified inshore and offshore zooplankton groups of both
holoplankton and meroplankton (Table 3.3.1-1) from oblique tows collected in spring 1976,
winter and spring 1977, and March 1979. Few of the holoplankton species identified from the
CalCOFI atlases were reported by Hatfield, possibly due to different sampling techniques and/or
sampling schedules. Further, Hatfield (1983) noted substantial differences in spatial distributions
and abundances of a number of zooplankton species associated with upwelling and seasonal and
localized current patterns. For example, plankton species that are characteristic of more northerly
latitudes were rare in the Gulf of the Farallones. Additionally, in the winter of 1977 when the
Davidson Current dominated the area, species typically seen nearshore were found farther
offshore and mixed with offshore forms.
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Table 3.3.1-1.
Dominant Zooplankton in Waters Offshore Central California Based
on a Review of CalCOFI Atlases, Hatfield (1983) and Tasto et al
(1981; 1975-1977 samples).
Nearshore = continental shelf waters; Offshore = seaward of the continental shelf;
summarized from Bence et al. (1992).
Holoplankton
Copepods
Euphausiids
Chaetognaths
Thaliaceans
Molluscs
Nearshore
Offshore
CalCOFI (as summarized in Bence et al. 1992}
Acartia tonsa
Calanus helgolandicus
Clausocalanus pergens
Ctenocalanus vanus
Metridia luceus
Tortanus discaudatus
Euphausia pacifica
Thysanoessa spinttera
Nyctiphanes simplex1
Sagitta enflata
Sagitta scrippsa/
Sagitta euneritica2
Dolioletta gegenbauri
Acartia danae
Calanus gracilis
Clausocalanus arcuicornis
Galdlus pungens
Plueromamma abdominalis
Euphausia gibboides
Euphausia mutica
Euphausia recurva
Thysanoessa gregaria
Sagitta bierii
Sagitta minima
Eukrohnia hamata
Thalia democratica
Pitteriella pecteti
Doliolum denticulatum
Salpa fusiformis3
Carinaria japonica
Limacina helicina
Limacina inflata
Clio pyramidata
Corolla spectabilis
AK0033.W51
3-98
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Table 3.3.1-1.
Continued.
Holoplankton
Copepods
Euphausiids
Chaetognath
Ctenophore
Meroplankton
Nearshore
Offshore
HatfieW (1983)
Acartia clausi
Tortanus discaudatus
Epilabidocera longipedata
Thysanoessa spinttera
Pleurobrachia bachei
Cancer productus zoeae (stages l-lll)
Cancer antemarius zoeae
Cancer gracilis zoeae (stages l-lll)
Pinnotherid zoeae (commensal crab)
Pagurid megalopa larvae (hermit crab)
Callianassa spp. larvae (ghost shrimp)
Grapsid crab zoeae (stages IV-V)
Porcellanid larvae (Anomuran decapods)
Upogebia pugettensis larvae
Xanthid zoeae (stages l-ll)
Majid zoeae I
Candacia bipinnata
Euchaeta japonica
Euchaeta acuta
Neocalanus cristatus
Neocalanus plunchrus
Eucalanus bungii
Nematoscelis difficilis
Thysanoessa gregaria
Sagitta scrippsae
Cancer productus zoeae (stages IV-V)
Cancer oregonensis zoeae (stages IV-V)
AK0033.W51
3-99
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Table 3.3.1-1.
Continued.
Holoplankton
Copepods
Chaetognath
Mollusc
Ctenophore
Meroplankton
Nearshore
Offshore
Tastoefa/.{1981}
Acartia claus?
Acartia longiremis*
Calanus pacificus3
Catenas tenuicorntf
Epilabidocera longipedata
Eucalanus bungif
Metridia lucens*
Pseudocalanus spp.2
Sagitta euneritica2
Limacina helicinef
Pleurobrachia bachei
Cancer gracilis zoeae (stages l-lll)
Cancer spp. larvae
Cancer antennarius zoeae (stages l-lll)
Callianassa spp. larvae
Porcellanid larvae
Grapsid zoeae (stages l-lll)
Majid zoeae3
Cancer gracilis zoeas (stages IV-V)
Cancer oregonensis (stages l-lll)
'Found only in some years; typically a more southern species.
2Neariy uniform distribution between nearshore and offshore areas.
3Large concentrations occasionally found nearshore/offshore.
AK0033.W51
3-100
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The Bence et al. (1992) categorized data for holoplankton and meroplankton from Tasto et a\.
(1981) into nearshore and offshore species (Table 3.3.1-1). Examples of peak densities for
certain forms of zooplankton include the following: the copepod Acartia clausi (15,0007100m3),
Cancer spp. larvae (2,500/lOOm3), and zoeae stages I-III for Cancer antennarius (1,2007100m3).
There were few holoplankton species common to the CalCOFI, Hatfield, and Tasto et al. reports.
For example, Table 3.3.1-1 shows that adult euphausiids were present in low abundances in
samples from 1975-1977 (Tasto et al. 1981), but three species (Euphausia pacifica, Nematoscelis
difficilis, and Thysanoessa gregaria) were more abundant in March 1979 samples taken on two
transects off San Francisco Bay (Hatfield 1983).
Using differences in species compositions and distributions that could be identified from CalCOFI
atlases, Hatfield (1983) and Tasto (1981) noted the following characteristics of zooplankton
distributions: (1) the dynamic nature of zooplankton distributions due to the complex
hydrography in the California Current system; and (2) the variance between data sets that likely
results from differences in sampling schedules, designs, and collection equipment. In addition,
taxonomic uncertainties remain for some species. For example, difficulties in the taxonomy of
Acartia may in part explain why A. tonsa and A. danae are identified as the most abundant
copepods in the CalCOFI atlases, while Tasto et al. (1981) identify A. clausi and A. longiremis
as most abundant and do not list A. tonsa and A. danae at ah1.
Ichthyoplankton
Ichthyoplankton (larval fish) are an important component of the zooplankton and have been the
focus of numerous CalCOFI surveys due to the importance of this group to commercial fishing.
Bence et al. (1992) summarized data from CalCOFI surveys by season and depth. The highest
ichthyoplankton abundances occurred over shallow water in winter, with lowest abundances at
deep stations in fall (Figure 3.3.1-1). Seasonal differences in total fish larvae showed some
variation among sampling stations, with highest overall values in winter and spring and lowest
values in summer and fall (Figure 3.3.1-1). The CalCOFI data are supplemented by data on
3-101
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i
i
CO
en
I
ra
6.5' •
5.5 •
3.5-
2.5
Winter
Spring
f----------:::;:;?;;*__
6.5"
5.5-
4.5-
(0
g.
(0
1
« 3.5 +
(0
2.5
Summer
I I 1—
900 1800 2700
Bottom Depth (meters)
Fall
3600
900 1800 2700
Bottom Depth (meters)
3600
Figure 3.3.1-1
Abundance of Total Fish Larvae Versus Bottom Depth (top panel) and by
Season (bottom panel).
Shown are least-squares means (LSMs) for logo transformed abundance collected during
CalCOFI surveys for individuals sampling stations (top panels) or by season (bottom panels).
PR = Point Reyes line, HMB = Half Moon Bay line, MB = Monterey Bay line. Seasons are
Dec.-Feb. = winter, March-May = spring, June-Aug. = summer, Sept.-Nov. = fall. Standard
errors of LSMs are indicated by vertical bars.
Source: Bence et al. 1992.
AK0088
3-102
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larval Pacific hake and shortbelly rockfish from a single ichthyoplankton survey conducted by
Bence et al. (1992). Preliminary analyses of these data suggest that at the time of the survey
Pacific hake larvae were relatively more abundant south of the Farallon Islands at depths greater
than 600 m (Figure 21 in Bence et al. 1992), with the relative abundance of short belly rockfish
being greatest at depths just beyond the shelf break and at depths greater than 1,800 m (Figure 23
in Bence et al. 1992).
Due to the inherent variability in plankton populations outlined above, the species composition
and distribution of zooplankton can be related to the LTMS study areas only in a general way.
Species common in nearshore waters would likely be present in Study Area 2. These include a
variety of holoplankton, and perhaps more importantly, most of the identified species of
meroplankton and ichthyoplankton, several of which become important to commercial fisheries
as adults. Zooplankton in offshore waters in the vicinity of Alternative Sites 3, 4, and 5 are
primarily holoplankton and late stages of Dungeness crab with smaller components of
meroplankton than occur in nearshore waters. Dominant species contributing to holoplankton
populations also are different in nearshore and offshore waters. Zooplankton serve as primary
prey items for other carnivorous zooplankton, pelagic invertebrates such as squid, adult fish,
seabirds, and marine mammals. Significant disruptions of normal planktonic productivity patterns
can negatively impact marine mammal and seabird populations. For example, a reduction in
planktonic productivity levels caused by the 1982-83 El Nino event led to high adult mortality-
and reproductive failure among numerous seabirds and marine mammals in the eastern
subtropical Pacific Ocean (Barber and Chavez 1983). This interdependence between lower
trophic level organisms and those higher in the food web demonstrates the ecological importance
of plankton within marine communities including those in the Gulf of the Farallones. Effects of
dredged material disposal on plankton populations are likely to be transitory at most and should
not result in impacts to food webs in the Gulf of the Farallones.
3-103
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3.3.2 Invertebrates
Information on infauna, demersal epifauna, pelagic invertebrates, and commercially important
species within the study region is presented in Sections 3.3.2.1 through 3.3.2.4, respectively.
3.3.2.1 Benthic Infauna
Benthic infaunal communities, defined generally as small invertebrates such as polychaete worms
and amphipods living within sediments, are described by a number of parameters, such as faunal
composition (what species are present), dominant taxa (which species are most abundant), density
(number of individuals/m2), diversity (number of different species relative to the total number of
individuals), species richness (number of species), and community assemblage patterns (which
species are usually found together in a sample or how similar the samples are to each other).
The following sections describe community parameters for Study Areas 2, 3, 4, and 5, including
Alternative Sites 3, 4, and 5. These descriptions are based primarily on recent EPA and Navy
surveys of the LTMS study region (SAIC 1992a,c).
Study Area 2
The infauna of Study Area 2 was typical of continental shelf habitats along the California coast.
The number of species collected from individual grab samples by SAIC (1992c) ranged from 95
to 131 per 0.1 m2, with a total of 261 species identified from 10 grab samples (Table 3.3.2-1).
Polychaete worms represented 48% of the total species and 76% of all individuals. Two genera
of surface deposit-feeding spionid polychaetes, Prionospio and Spiophanes, contributed 50% of
the individuals. Amphipod crustaceans and gastropod snails were the next most dominant taxa.
Gastropods were much more diverse in Study Area 2 than in any of the other LTMS study areas
surveyed. Major infaunal taxa found only in Study Area 2, and absent from the slope areas,
included decapods, mysids, ostracods, and phoronids. Taxonomic groups typical of the deep sea,
including pogonophorans, aplacophoran molluscs, and isopod and tanaidacean crustaceans, were
either absent or collected infrequently in Study Area 2.
3-104
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Table 3.3.2-1.
Total Number of Species Belonging to Each Major Taxonomic Group
Collected from Study Areas 2, 3, 4, and 5 (SAIC 1992c,d).
Taxon
(Number of Samples)
Porifera
Coelenterata
Anthozoa
Platyhelminthes
Nemertinea
Annelida
Hirudinea
Oligochaeta
Polychaeta
Pogonophora
Sipuncula
Echiura
Mollusca
Aplacophora
Bivalvia
Gastropoda
Scaphopoda
Arthropoda
Amphipoda
Cumacea
Decapoda
Isopoda
Leptostraca
Mysidacea
Ostracoda
Tanaidacea
Phoronida
Echinodermata
Asteroidea
Echinoidea
Holothuroidea
Ophiuroidea
Hemichordata
Enleropneusta
Urochordata
TOTAL
Study Area 2
(10)
—
3
1
1
1
1
125
—
2
1
1
18
27
2
33
13
3
5
1
1
4
1
1
1
4
10
_
1
261
Study Area 3
(18)
—
2
1
8
1
1
232
1
5
—
13
25
9
2
33
30
45
1
47
—
1
2
2
12
2
—
475
Study Area 4
(14)
—
2
1
6
1
234
1
3
—
13
23
15
31
32
41
43
—
3
" 12
1
—
462
Study Area 5
(21}
1
4
3
14
1
184
2
3
0
11
19
3
1
39
21
39
23
—
1
1
6
8
1
—
385
AK0034.W51
3-105
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Infauna densities (individuals/m2) were highest in Study Area 2 with spionid and capitellid
polychaetes predominant at stations with the highest densities (Table 3.3.2-2). These high
densities probably are caused by relatively high productivity in the surface waters in this
continental shelf location (see Section 3.2.3). From approximately 75 to 125 m depth, infaunal
densities exceeded approximately 20,000 individuals/m2, decreasing to less than 15,000 near the
shelf break (approximately 200 m depth).
Species diversity, measured by Hurlbert's rarefaction (number of expected species per 100
individuals) or by the Shannon-Wiener index (//'), also was high, although these measures
showed an increase in species diversity with increasing depth within the study area. In contrast,
species richness did not show a depth-related pattern (SAIC 1992c). Similarity analysis showed
that the two deepest stations were different from the remaining stations, indicating a distinct
fauna! break between 125 and 180 m depth (SAIC 1992c).
Study Area 3
The number of species collected from individual box core samples within Study Area 3 ranged
from 59 to 165 per 0.1 m2, with a total of 475 species identified from 18 box core samples
(Table 3.3.2-1). Subsurface deposit-feeding polychaete worms of the families Paraonidae,
Cossuridae, and Cirratulidae each contributed between 9 and 11% of the entire infauna, and
represented 49% of the total species collected. Detrital-feeding or scavenging tanaidacean and
isopod crustaceans were the next most dominant taxa, each representing 9% of the total number
of species collected by SAIC (1992c). The filter-feeding amphipod Photis "blind" was extremely
abundant at five stations, and by itself accounted for almost 18% of the entire fauna. Because
Study Area 3 stations occur over a large depth range (depths from 610 to 2,005 m), half of the
dominant species collected were abundant at only a single station. The subsurface deposit-
feeding polychaetes Tharyx sp. 1, Cossura pygodactylata, Cossura rostrata, andAricidea ramosa
were the most common species of the taxa that predominated. The most common crustacean was
the tanaidacean Pseudotanais sp. 7, and the most common mollusc was the aplacophoran
Scutopidae sp. 2.
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Table 3.3.2-2.
Benthic Infaunal Community Parameters for Study Areas 2, 3, 4, and
5 (SAIC 1992a,c).
Data for Alternative Sites 3, 4, and 5 are included in parentheses.
Area
(Alternative Site)
Study Area 2
Range
*±1SD
No. Samples
Study Area 3
(Alternative
Site 3)1
Range
X±1SD
No. Samples
Study Area 4
(Alternative
Site 4)2
Range
X±1 SD
No. Samples
Number of
Species
Density
(Ind/m2)
Hurlbert's rarefractkm
(Species per 100 Ind.)
Shannon-
Wiener
Index (tf)
Evenness'
M
95-131
114112.7
10
12,920-
42,490
26,870
±13,017
10
26.340.6
32.9 ±4.9
10
4.12-5.37
4.67 ±0.43
10
0.626-0.784
0.685
±0.058
10
-
59-165
(100-165)
115 ±34.6
19(4)
3300-19560
(7840-
19,560)
10,303
±4590
(14,810
±5574)
19(4)
22.9-54.9
(34.7-50.5)
40.2 ±7.6 (39.5 ±7.6)
19(4)
3.55-6.24
(4.02-6.05)
4.98 ±0.75
(4.64 ±0.98)
19(4)
0.534-0.855
(0.534-
0.822)
0.649
(0.13)
19(4)
63-164
(121-143)
118.5
±27.9
(132
±11.0)
14(3)
4530-
13,190
(9310-
13,190)
8446
±2314
(10,947
±2010)
14(3)
33.2-57.2
(33.2-49.5)
44.8 ±6.8
(42.6 ±8.43)
14(3)
4.28-6.34
(4.28-5.84)
5.46 ±0.53
(5.1 7 ±0.8)
14(3)
0.619-0.886
(0.619-
0.830)
0.798
±0.66
(0.734
±0.107)
14(3)
AK0035.W51
3-107
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Table 3.3.2-2.
Continued.
Area
(Alternative Site)
Study Area 5 (1990)
(Alternative
Site 5)3
Range
X±1SD
No. Samples
Study Area 5
(Alternative
Site 5)4
Range
X±1SD
No. Samples
Number of
Species
Density
(tact/m*}
Hurlbert's rarefraction
(Species per 100 Ind.)
Shannon-
Wiener
index (W)
Evenness
(/)
77-131
(90-91)
105.9
±16.9
(90.5)
10(2)
4970-9870
(4970-
5290)
7715
±1706
(5130)
10(2)
33.3-50.9
(41.9-43.8)
44.0 ±5.4
(42.9)
10(2)
4.35-5.96
(5.31-5.35)
4.94 ±1.58
(5.33)
10(2)
0.694-0.862
(0.818-
0.822)
0.810
±0.51
(.820)
10(2)
44-97
(44-73)
74.4 ±15.4
(56 ±15.1)
10(3)
750-7540
(750-5790)
4450
±1953
(3123
±2533)
10(3)
27.2-44.5
(29.8-34.5)
37.5 ±5.8
(32.2)
9(2)
3.45-5.23
(3.62-5.23)
4.71 ±0.68
(4.47 ±0.81)
10(3)
0.582
(0.582)
0.582-0.959
(0.638-
0.959)
10(3)
1 Alternative Site 3 stations were 3-13, 3-17,3-18, and 3-19 (SAIC 1992c).
2 Alternative Site 4 stations were 4-4,4-6, and 4-11 (SAIC 1992c).
3 Alternative Site 5 stations from the 1990 samples were F-17, K-15, and L-17 (SAIC 1991).
4 Alternative Site 5 stations from the 1991 samples were B-4, B-5, and B-7 (SAIC 1992a).
* Sample size was too small to calculate this parameter.
AKOQ35.W51
3-108
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Densities (number of individuals/m2) in Study Area 3 ranged from 3,300 at 800 m to 19,560 at
1,780 m depth, respectively (SAIC 1992c). The highest densities were found at deep stations
(depths greater than 1,780 m) due to dense populations of the amphipod Photis "blind." Elevated
densities at other stations within Study Area 3 were due to dense assemblages of polychaetes in
the families Paraonidae, Cirratulidae, and Cossuridae. The lowest densities were observed at
stations between 800 and 985 m depth, located within the OMZ. These stations were dominated
by oligochaetes, which are frequently associated with low dissolved oxygen, and cossurid or
paraonid polychaetes.
Generally, there was a trend toward increasing species diversity and species richness with
increasing depth across the continental slope stations. The diversity of infauna in Study Area 3
was high, especially at some of the deepest stations (SAIC 1992c). Low diversity at three deep
stations was due to the abundance of Photis "blind."
Species richness was lowest at stations ranging in depth from 800 to 985 m and corresponding
to the lower edge of the OMZ (Figure 3.3.2-1). The number of species per station increased
slightly with depth between 1,000 and 1,500 m, and then showed a pronounced increase at depths
greater than 1,600 m. Similarity analysis for Study Area 3 showed two main clusters that are
defined by depth, with a distinct break at 1,600 m (SAIC 1992c).
The infauna at four stations (3-13, 3-17, 3-18, and 3-19; SAIC 1992c) located within the
depositional area (including Alternative Site 3), was characterized by three predominant species
groups, two groups of which were similar to other nearby stations outside the depositional area.
The two similar groups were based on the polychaete Tharyx sp. 1, and the amphipod Photis
"blind." All the stations within Alternative Site 3 were variable in species composition, similar
to the other stations throughout Study Area 3. This is notable considering the more limited depth
range of Alternative Site 3 (1,450-1,900 m) as compared to Study Area 3. The third species
group, represented by Station 3-19 within Alternative Site 3, had the most species (165) of any
3-109
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180
160-
c
O no-
3
CO
Q)
O.
CD
o
0)
Q.
CO
B
o3
n
E
D
120-
100-
60-
20-
0-
4 10
3 19
314 3 ,B
413
4-15
4 14
4-4
320
C 1
3-3
4-8
4-7
3-15
3 10
4-*
_ai
C-2
3-4
t*
550 BOO 985 1010 J025 119
3-17
,7
7
"31^!
45
C-7
3-a
TB—rcr
DS2
OS3
DS4
J235 J400 {45} J505 J87S 1730 {760 J780 IwA Iwi 2*005 ioeiisM 3o60
610 812 995 1020 1040 1220 1225 1338 1427 1480 1560 1730 1745 UU) 1820 1B80 19!X> 2010 2205 2/55
Depth (m)
Figure 3.3.2-1. Bar Graph of the Total Number of Species at each Station in LTMS
Study Areas 3,4, and Pioneer Canyon, Arranged by Depth.
-------
station sampled within the entire study region and was characterized by the lack of true dominant
species (Figure 3.3.2-1).
Study Area 4
The number of species collected from individual box core samples within Study Area 4 ranged
from 63 to 164 per 0.1 m2 (Table 3.3.2-2), with a total of 462 species identified from 14 samples
(Figure 3.2.2-1) (SAIC 1992c). Polychaete worms comprised 51% of the total species collected,
while tanaidacean and isopod crustaceans each accounted for 10% (Table 3.3.2-1). Similar to
Study Area 3, the filter-feeding amphipod Photis "blind" was the most abundant crustacean,
accounting for 26% of the individuals collected at Station 4-11 (1,970 m depth). Different
dominant species characterized the individual stations within Study Area 4. Subsurface deposit-
feeding polychaete species including Tharyx sp. \,Aricidea simplex, and Cossura pygodactylata
were predominant. Three stations (4-5, 4-12, and 4-13) within Study Area 4 lacked a true
dominant, with the top ranking polychaete comprising less than 10% of the animals collected.
Densities (number of individuals/m2) in Study Area 4 ranged from 4,530 (812 m depth) to 13,190
(1,427 m depth) (SAIC 1992c). The overall range in total density was not as great as that noted
for Study Area 3 (Table 3.3.2-2) even though high Photis densities were observed at Stations
4-10 and 4-11 (1,760 and 1,970 m depth, respectively). Most of the variability observed in
densities at individual stations was due to paraonid, cirratulid, and cossurid polychaetes. Similar
to Study Area 3, the lowest densities in Study Area 4 were found in the OMZ at Station 4-14
(812 m depth). Station 4-4 (1,427 m depth) exhibited the highest density in Study Area 4,
primarily due to high abundances of the polychaetes Paraonella monilaris and Tharyx sp. 1.
Generally, infaunal diversity in Study Area 4 was comparable to that found in Study Area 3,
although both the minimum and maximum values for the Shannon-Wiener index of diversity (Hf)
were somewhat higher than for Study Area 3 (Table 3.3.2-2). Some stations having lower
3-111
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diversities were dominated by exceptionally high numbers of Tharyx sp. 1 (Station 4-4, 1,600 m)
and Photis "blind" (Stations 4-10 and 4-11, 1,900 m).
As in Study Area 3, stations in Study Area 4 located closest to the OMZ (approximately 800 m
depth) had a distinctly lower species richness than stations between 1,000 m and 1,600 m.
Additionally, a pronounced increase in species richness was noted at stations between 1,700 and
2,000 m depth (Figure 3.3.2-1).
Similarity analysis showed two main species groups defined by proximity to Pioneer Canyon
rather than by depth (SAIC 1992c). One group of stations, dominated by the polychaetes
Cossura pygodactylata and Aricidea simplex, occurred in the northern half (closer to Pioneer
Canyon) of Study Area 4, while the second group included stations in the southwestern part of
this study area (including Alternative Site 4).
Three infauna sampling stations, 4-4, 4-6, and 4-11, ranging in depth from 1,427 to 2,010 m,
were included within Alternative Site 4. These stations were relatively dissimilar to one another
with respect to infaunal communities in Study Area 4. Station 4-4 was characterized by
extremely high numbers of a single species (Tharyx sp. 1), and also was the least diverse of any
station in the study area. Station 4-6 was the deepest station (2,010 m) and had a low similarity
with other stations in its group, due to predominant deep-sea species such as Levinsenia sp. 5 and
Aricidea cf. catherinae. Thus, while densities at Station 4-6 were low, diversity was among the
highest seen in Study Area 4. In contrast, Station 4-11 (associated with the southwest group
away from the Pioneer Canyon) was dominated by Photis "blind" and had the greatest number
of species (tied with Station 4-5) found in an individual sample in Study Area 4.
Study Area 5
Study Area 5 is located on the lower continental slope/continental rise, with most samples
collected deeper than 2,400 m. In 1990 and 1991, 18 box core samples were collected within
3-112
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this study area and another seven were taken in an adjacent area approximately 5 nm to the south
(SAIC 1992a,c). Most of the summary information presented in this section refers only to those
samples collected within Study Area 5.
Of the 385 species of infauna collected in Study Area 5 (Table 3.3.2-1), polychaetes comprised
48%, crustaceans 32% and molluscs 8%. The remaining 45 species represented a variety of other
taxa. Many of these taxa are typical of the deep-sea infaunal communities, including carnivorous
or scavenging aplacophoran molluscs, tube-dwelling pogonophorans, and detrital-feeding
desmosomatid isopods and tanaidaceans, and were also important faunal elements in Study Areas
3 and 4. The highest infaunal densities (number of individuals/m2) in Study Area 5 were
recorded in 1990, ranging from 4,970 to 9,870. Densities from the 1991 survey were lower and
more variable, ranging from 750 to 7,540. Species diversities, like the densities, were higher in
1990 than in 1991.
Similarity analysis indicated that the infaunal community was distributed by depth, with deeper
stations (between 2,700 and 3,000 m depth) grouped together and more similar than stations
along the 2,400 m isobath (SAIC 1992c). When stations along isobaths were grouped, different
dominant taxa became characteristic. For example, stations along the 2,400 m depth contour
were dominated by a large paraonid polychaete (Aricidea simplex), whereas the stations occurring
along the 2,700 m depth were dominated by the polychaetes Prionospio delta, Chaetozone sp.
1, and Aricidea simplex. Predominant taxa collected at stations on the 3000 m contour included
the polychaetes Prionospio delta, Levinsenia nr.flava, and the aplacophoran Spathoderma sp. 1.
Alternative Site 5 is in the same approximate location as the Naval Ocean Disposal Site (NODS)
described in SAIC (1992a). This encompasses an area of approximately 2 x 2 nm at the
southwest corner of the Chemical Munitions Dumping Area (CMDA), at depths ranging from
2,800 to 3,050 m, that was surveyed in part by the Navy (SAIC 1992a). Five box cores were
taken within Alternative Site 5: Stations E-19 and F-17 in 1990 and B-l, B-4, and B-5 in 1991
(SAIC 1992a,c).
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The values of benthic community parameters in Alternative Site 5 were generally higher in 1990
than in 1991, similar to the overall results for Study Area 5. One station (B-5) within this
alternative site had the lowest infaunal densities recorded (750 per m2) within any study area.
In contrast, if Station B-5 is excluded, the remaining 1991 stations averaged 4,310 per m2 and
the two 1990 stations averaged 5,130 per m2. The most abundant infaunal species in Alternative
Site 5 was the spionid polychaete Prionospio delta, a surface deposit feeder characteristic of
lower slope and rise depths.
Two benthic surveys were conducted in Area 5 (SAIC 1991, 1992a,c). Seven stations sampled
in 1991 had lower infaunal densities than any station sampled in 1990. These stations include
the deepest stations in the trough of the Chemical Munitions Disposal Area (CMDA) which are
mostly within Alternative Site 5, the deepest stations on the southern flank of the CMDA, and
the two deepest stations sampled in an adjacent area 10 miles to the south. None of these
stations is close to any station sampled in 1990, except for B-5, which is very close to Station
F-17 (1990) that had infaunal densities of more than 5,000 individuals per m2. The reason that
the densities at these two stations differ by a factor of 7 may be a disturbance of the
environment. Bottom photographs taken as a towed camera sled crossed the coordinates of these
stations revealed a lumpy bottom that suggested a local disturbance, possibly related to turbidity
flow. It is not known when this disturbance took place, but the low infaunal densities at Station
B-5 in 1991 compared with the high values at Station F-17 in 1990 suggest that it occurred after
August 1990. The identification of a natural disturbance in Alternative Site 5 is of considerable
interest in evaluating the effects of dredged material disposal on benthic infaunal populations.
The data derived from the single box core taken from Station B-5 suggest that, although the
expected species such as Prionospio delta and the typically dominant aplacophorans and deposit-
feeding polychaetes are present, they occur in greatly reduced numbers. It is not known whether
the resident population at this station is a remnant of the pre-disturbance fauna or a result of
specimens that were recruited to the site after the disturbance. (See Section 4.4.2.2 for a general
discussion of impacts of burial on the benthos.)
3-114
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Comparisons Between Study Areas
The most characteristic feature distinguishing Study Area 3 from the other LTMS study areas
sampled on the continental slope is the relatively high variability of parameters such as diversity,
species richness, and density. The wide ranges in these parameters primarily are related to
extremely high abundances of two species, the filter-feeding amphipod Photis "blind" and the
deposit-feeding polychaete Tharyx sp. 1, that make up large percentages of the total infauna at
1,900 and 1,400 m depths, respectively. The most common (frequently occurring) species in
Study Area 3 (not necessarily the most abundant) were Tharyx sp. 1, Cossura pygodactylata,
C. rostrata, Aricidea ramosa, Pseudotanais sp. 7, and Scutopidae sp. 2. Similarity analyses
revealed that the infaunal community was clearly zoned by depth, with a major faunal break
occurring at 1,600 m.
Infaunal community parameters were less variable in Study Area 4 than in Study Area 3 and are
within the range of those reported for Study Area 3. This characteristic is related to lower
densities of Photis "blind" and Tharyx sp. 1 found at the same depths as in Study Area 3. In
addition, although the most common polychaetes in both areas belong to the same families, the
overall faunal composition of Study Area 4 is slightly different from that of Study Area 3, These
differences most likely are attributable to differences in sediment characteristics. Similarity
among stations within Study Area 4 also is influenced by sediment characteristics. Cluster
analysis indicated two main groups of stations that are divided by a narrow band of very sandy
sediment crossing Study Area 4 from northwest to southeast.
In a broad sense, Study Area 5 is somewhat less rich in terms of the numbers of species,
compared to Study Areas 3 and 4, and has lower infaunal densities. This latter result is expected
because of trends of decreasing density with depth in continental slope environments on both
coasts of North America (SAIC 1992a; Blake et al. 1987). Structurally, the benthic infauna of
Study Area 5 are similar to Study Areas 3 and 4 in that the most common speceis belong to the
polychaete families Paraonidae, Cirratulidae, and Cossuridae. One important difference is the
3-115
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dominance in Study Area 5 of a surface deposit-feeding spionid polychaete, Prionospio delta, in
the 2,7000 to 3,000 m depth range. Cluster analysis reveals a faunal break between 2,400 and
2,700 m, and this break can be attributed to this spionid (SAIC 1992a). Spionids are not
dominant in Study Areas 3 and 4. Prionospio delta is the dominant infaunal species in
Alternative Site 5. Available data suggest that spionids would be more susceptible to burial than
subsurface deposit-feeders (Jumars 1977), but are, in turn, more likely to rapidly recolonize a
disturbed environment.
From a trophic standpoint, differences in the types of organisms at each alternative site are
expected to result in differences in their responses to dredged material. For example, Alternative
Site 3 is dominated by filter-feeding amphipods, while amphipods are less important in
Alternative Site 4, which is dominated by subsurface deposit-feeders. The filter-feeding
amphipods would be the most susceptible to dredged material disposal because of their feeding
activities and relative inability to burrow out of deposits. It is possible, however, that they might
be able to move away from an affected site. Surface deposit-feeders have been shown to be
more susceptible to burial than subsurface deposit-feeders (Jumars 1977). All three areas and
their alternative sites include numerous species of tanaidaceans and isopods. These small
crustaceans are mostly detrivores, feeding on paniculate material on the surface of the sediment.
It is likely that they will be highly susceptible to dredged material deposits.
Thus, the response of the benthic infauna in each of the areas and alternative sites is mixed from
a trophic standpoint. The greatest impact would clearly be in Alternative Site 3, where the
populations of highly sensitive filter-feeding amphipods are the most dense. It is likely that the
dominant spionids in Alternative Site 5 also would be sensitive, but because overall species
richness and density is lower, the composite impact would be less than in Alternative Site 4.
Comparisons With Other Studies
The Continental Shelf—Study Area 2. The occurrence of 261 infaunal species from only ten 0.1
m2 samples in Study Area 2 is remarkably high when compared with the MMS Monitoring
3-116
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program in Santa Maria Basin where 886 species were collected from 551 0.1 -m2 box core
samples over a three-year period (Hyland et al. 1991). The diversity estimates from Study Area
2 are similar to those recorded from similar depths in the Santa Maria Basin (Hyland et al.,
1991), but higher than those recorded by Parr et al. (1987) from stations within and adjacent to
Study Area 2 (Table 3.3.2-2). This suggests that the Study Area 2 infauna is very rich and does
not differ in that regard from other well-studied shelf and upper slope areas off California.
The lower range of the densities measured in Study Area 2 by SAIC (1992c) is comparable to
some stations sampled as part of the MMS Northern and Central California Reconnaissance and
Santa Maria Basin programs (SAIC 1989b; Hyland et al. 1991). However, the densities (number
of individuals/m2), ranging between 30,000 and 40,000, are among the highest values ever
recorded in eastern Pacific waters and comparable to environments such as Georges Bank off
Massachusetts (Neff et al. 1989).
Parr et al. (1987) found much lower total densities (number of individuals/m2) ranging from
3,400 to 6,200 in Study Area 2. The variation in diversities and densities among the various
studies may be due to differences in sampling techniques. For example, samples collected by
SAIC (1992c) in Study Area 2 and by Hyland et al. (1991) were live-sieved through a 0.3-mm
sieve in the field and subsequently resieved through nested 0.3 and 0.5-mm mesh sieves in the
laboratory. In contrast, Parr et al. (1987) used live-sieving techniques with 0.5-mm screens.
Thus, two different methods were used to separate the fauna from the sediments. Although no
comparative data are available from samples taken at the same site, it is evident that the 0.3-mm
sieve retains many more specimens than a 0.5 mm mesh screen when live-sieved in the field.
The overwhelming dominance of spionid polychaetes noted by SAIC (1992c) was not apparent
in the data from a previous study by Parr et al. (1987), who reported very different communities
at three sites within or adjacent to Study Area 2. The most abundant species from SAIC (1992c)
were the paraonid polychaete Aricidea catherinae and the bivalve Axinopsida serricata, whereas
the spionid Spiophanes missionensis was predominent at one of the Parr et al. stations. The top
3-117
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ranking species of each station in both SAIC (1992c) and Parr et al. (1987) accounted for
between 7% and 10% of the total fauna. Although similar species composition was found among
stations in Study Area 2, almost all the predominant species collected by SAIC (1992c) were rare
at stations sampled by Parr et al. (1987), and vice versa. These differences probably are due to
the sieve size differences discussed previously rather than to real year-to-year differences.
The Continental Slope—Study Areas 3, 4, and 5. Infaunal species composition from the eastern
Pacific continental slope is very similar to the Western North Atlantic, as identified in a study
that used comparable methods, (Blake et al. 1987; Maciolek et al. 1987a,b). However, some
notable differences include the absence of the polychaete family Chrysopetalidae and the lower
number of pognophoran species in the Pacific.
The continental slope represents a rich source of biodiversity (Grassle and Maciolek 1992).
Species richness estimates from the Navy and EPA samples from the continental slope off San
Francisco are very high when compared with the continental shelf environment. However, they
are lower overall than those in the western North Atlantic (see Blake et al., 1985). The major
difference between the western North Atlantic and eastern Pacific faunas is that infaunal densities
are much higher off California. The maintenance of high species richness in deep-sea habitats
where certain individual species achieve high densities was first reported by SAIC (1991) and
SAIC (1992a) as part of the Navy surveys in Study Area 5.
Although the lack of replicates from the EPA and Navy studies precludes developing site-specific
estimates of species accumulation, it is evident that species are continuously added with
additional sample collections (Figure 3.3.2-2). However, these estimates must be viewed with
some caution since the EPA samples encompassed a much greater depth range and variety of
sediment types than the Navy samples. Nevertheless, Figure 3.3.2-2 indicates that leveling-off
does not occur after 68 samples from slope depths ranging from 550 to 3,050 m. These results
clearly support the concept of high species richness in deep-sea habitats.
3-118
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800
u>
C/)
Number of Samples
Figure 3.3.2-2. Species Accumulation Curve for 68 Samples Collected in
Study Areas 3,4, and 5 in 1990 and 1991.
-------
Figure 3.3.2-3 represents a composite profile of similar depth intervals from the Navy and EPA
studies off the Farallones (SAIC 1992a,c), a transect off Cape Lookout, North Carolina (Blake
et al. 1985), and a transect off Massachusetts (Maciolek et al. 1987H). The most obvious
difference between transects done on the slope in the LTMS study region and those from the
Atlantic is the higher density in samples collected from middle and lower slope depths off
California. High benthic productivity in middle and lower slope depths off California very likely
is due to a high flux of phytal detritus to the seabed (SAIC 1992c). For example, evidence
derived from measurements of carbon-nitrogen ratios, stable isotopes (515N, 813C), and
chlorophyll a and phaeopigments in the sediments from Study Area 5 suggests that phytodetritus
flux is higher than has previously been measured in the deep sea (SAIC 1992c). While
phytoplankton is known to impinge on the seabed in the Atlantic (Hecker 1990), the fluxes
appear to be more seasonal and irregular than in the eastern Pacific, where surface productivity
associated with upwelling extends over longer time intervals (see Sections 3.2 and 3.3). The very
marked decrease in densities between 800 and 1,000 m depth off California may be associated
with the presence of the OMZ which may vary in depth between 600 and 1000 m. There is no
comparable OMZ in the Atlantic, where infaunal densities decline more or less evenly with
depth.
Factors Influencing Community Patterns
In typical marine infaunal communities, the dominant taxa are polychaetes. Polychaetes of the
families Paraonidae, Spionidae, Cossuridae, and Cirratulidae were predominant at most stations
in Study Areas 2, 3, 4, and 5 . However, in Study Area 3, unusually high densities of the
amphipod Photis "blind" were observed between 1,745 and 2,000 m depth. Filter-feeding
amphipods are common in nearshore environments. The amphipods remove particles from the
water for food and tube construction. For dense populations of such amphipods to persist,
sediment transport mechanisms must be present to move organic materials over the site.
3-120
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OJ
o-
550
Faiallonea Slo|x>
Carolina Slopo
North AU Slope
1500
2500
1000
2000
3000
Depth (m)
Figure 3.3.2-3. Infaunal Densities at Two Transects on the U.S. Atlantic Continental
Slope and Rise and One Transect off the Farallon Islands.
-------
In summary, the infaunal slope communities off San Francisco are clearly zoned by depth (SAIC
1992c). Sediments change from sands to fine silty muds at about 1,800 m, corresponding to one
of the faunal breaks observed. The upper slope is influenced by the OMZ, especially between
600 and 1,000 m depth where oligochaetes are present in the fauna and indicative of sites with
some partial oxygen stress.
3.3.2.2 Demersal Epifauna
This section describes the demersal epifaunal invertebrate communities found in the study region,
including Study Areas 2, 3, 4, and 5. Extensive trawl and remotely operated vehicle (ROV)
studies were conducted by the Environmental Protection agency (EPA) in Study Areas 2
through 4 and adjacent sites within Pioneer Canyon and at "Mid-Depth" sites during September
and October 1991 (SAIC 1992b). U.S. Navy surveys of Study Area 5 were conducted during
July 1991 using beam trawls, otter trawls and camera sled tows (Nybakken et al. 1992; SAIC
1992a). Previous trawl studies within Study Area 2 were conducted by KLI (1991).
Similar to general distributional patterns observed for infaunal invertebrate communities (Section
3.3.2.1), megafaunal communities in the study region also are differentiated based on depth or
depth-related factors. Types of depth-related factors recognized as influencing megafaunal
community structure include differences in the sedimentary environment, the OMZ, and regional
current patterns (Wakefield 1990) within the study region. Characterizations of each LTMS
study area regarding "low, moderate, or high" parameters are relative comparisons with other
SAIC (1992b) transects. These communities are summarized below and discussed in greater
detail later in this section.
A shelf community (from depths of at least 72 m to approximately 200 m),
including Study Area 2 and some Mid-Depth locations, was characterized by
low numbers of megafaunal species, density, and biomass. This community
is characterized by brittlestars, seastars, sea pens, and octopus. Dungeness
crab and squid collected infrequently and in low abundances in this study area
are the only species which have commercial value.
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-------
Upper and middle slope communities (from depths of approximately 200 m
to 500 m and 500 m to approximately 1,200 m), including shallow parts of
Study Areas 3 and 4, Mid-Depth, and Pioneer Canyon, were characterized by
moderate to high numbers of species. Density and biomass were moderate to
high due to species such as Tanner crabs, seastars, brittlestars, snails, and sea
cucumbers. Tanner crabs were collected in high numbers but do not appear
to be of significant commercial value in the study area.
A lower slope community (from depths of approximately 1,200 m to at least
1,800 m), including the deeper parts of Study Areas 3 and 4, is characterized
by a relatively high number of species including taxonomic groups such as sea
cucumbers, brittlestars, seastars, and sea pens. Densities and biomass in these
areas also were relatively high and represented primarily by sea cucumbers,
brittlestars, and seastars.
A continental rise community (from depths of approximately 2,000 m to
almost 4,000 m), including Study Area 5, is characterized by low numbers of
megafaunal taxa, densities, and biomass. However, this area is characterized
by similar species composition to Study Areas 3 and 4, with predominant
species including sea cucumbers, brittlestars, seastars, and sea pens (Nybakken
et al. 1992).
Study Area 2
Demersal megafaunal communities within the study region exhibited several distinct patterns in
the number and type of species (Figure 3.3.2-4), density (Table 3.3.2-3A), and biomass (Table
3.3.2-3B). The total number of megafaunal species collected during trawl surveys by SAIC
(1992b) in Study Area 2 ranged from 8 to 12 (Figure 3.3.2-4). Dominant taxonomic groups in
this area typically included echinoderms (particularly seastars and brittlestars), cnidarians (sea
pens), and molluscs (octopus). Overall, densities in this study area were low and ranged from
0.29 to 64.6 individuals per hectare (Figure 3.3.2-5). Echinoderm densities (Table 3.3.2-3A) for
taxa such as brittlestars and sand stars (Luidia foliolatd) ranked highest, with sea pen and
crustacean densities also ranking in the top five, but often in much lower densities. Biomass in
this study area generally was low for individual taxonomic groups, ranging from 0.04 to 2.83 kg
per hectare (Figure 3.3.2-6). Biomass was highest for anemones (Metridium spp.; between 0.42
3-123
-------
40 -i
30-
o
ui
Q.
10
U.
o
ca
2
ID
Z
20 -
10-
2
B
7
2
2
A
8
5
2
C
8
5
M
D
2
1
2
8
M P
D C
1 1
2
5
2
4
9
5
M
D
3
5
0
4
P
C
2
6
7
5
3
B
1
0
0
8
3
C
1
1
4
3
P
C
3
1
1
7
0
4
B
1
2
7
8
4
A
1
4
5
8
TRANSECT BY AVERAGE DEPTH (M)
TAXAGRP
Coelenterates
1\\\N Echinoderms
Other
L
J
Crustacea
Molluscs
3
A
1
6
5
6
4
C
6
4
Figure 3.3.2-4.
Number of Benthic Megafaunal Invertebrate Species by General Taxonomic Group
Collected During Trawl Surveys by SAIC (1992b) at Each Transect;
Transects Sorted in Order of Increasing Depth.
Average Depth (m) is indicated beneath each transect.
-------
Table 3.3.2-3A. Rank Order of Density for Demersal Megafaunal Invertebrates Collected During Trawl Surveys by SAIC (1992b) in
Study Areas 2 through 4 and Adjacent Sites in Pioneer Canyon (PC) and in "Mid-Depth" (MD).
SPECIES
(depth in meters)
Unknown Ophiuroid spp. 1
brittlestar
Luidia foliata
sand star
Stylatula spp. 1
sea pen
Metridium
anemone
Octupus wbescens
octopus
Asteronyx loveni
brittlestar
Cancer magister
Dungeness crab
Hippasteria spinosa
seastar
Unknown Ophuiroid, Gray
brittlestar
Pleurobranchia
opisthobranch gastropod
Rathbunaster californicus
seastar
Gorgonocephalus
brittlestar
2A
(72)
1
2
3
4
5
-
-
-
-
-
-
-
2B-3
(85)
-
-
-
2.5
2.5
2.5
2.5
5
-
-
-
-
2C-1
(85)
-
2
-
5
3
-
-
-
1
4
-
-
MD2-1
(128)
-
-
3
4.5
-
-
-
-
-
-
1
2
MD1-1
(252)
-
4
-
-
-
-
-
-
-
-
5
-
PCM
(495)
-
-
5
-
-
2
-
-
-
-
-
-
MD3-1
(504)
-
-
-
-
-
2
-
-
-
-
-
-
PC2-1
(675)
-
-
-
-
-
3
-
-
-
-
-
-
38-1
(1008)
-
-
-
-
-
-
-
-
-
-
-
-
3O1
(1143)
-
-
-
-
-
4
-
-
-
-
-
-
PC3-1
(1170)
-
-
-
-
-
-
-
-
-
-
-
-
48-2
(1278)
-
-
-
-
-
-
-
-
-
-
-
-
4C-1
(1458)
-
-
-
-
-
-
-
-
-
-
-
-
4A-1
(1656)
-
-
-
-
-
2
-
-
-
-
-
-
3A-1
(1764)
-
-
-
-
-
2
-
-
-
-
-
-
AKC036.W51
-------
Table 3.3.2-3A.
Continued.
SPECIES
(depth in meters)
Parastichopus simpsoni?
sea cucumber
Pandalus platyceros
spot prawn
Allocentrotus Iragilis
sea urchin
Myxoderma platyacanthum
seastar
Pannychia
sea cucumber
Unknown Pagurid Crab
Hermit crab
Neptunea lyrata
snail
Chionoecetes fanner/
Tanner crab
Ophiomusium jollensis
brittlestar
Bathybembix bairdii
snail
Hormathiidae
anemone
Heterozonias alternates
seastar
2A
{72)
-
-
-
-
-
-
-
-
-
-
-
-
28-3
(85)
-
-
-
-
-
-
-
-
-
-
-
-
2C-1
(85)
-
-
-
-
-
-
-
-
-
-
-
-
MD2-1
028}
4.5
-
-
-
-
-
-
-
-
-
-
-
MD1-1
(252)
1
2
3
-
-
-
-
-
-
-
-
-
PCM
(495)
-
-
-
1
3
4
-
-
-
-
-
-
MD3-1
(504)
-
-
-
1
5
4
3
-
-
-
-
-
PC2-1
(675)
-
-
-
1
-
-
2
4
5
-
-
-
3B-1
{1008}
-
-
-
-
2
-
4
3
-
1
5
-
3C-1
0143)
-
-
-
-
-
-
2
1
-
-
-
4
PC3-1
(1170)
-
-
-
-
-
-
2
4
3
1
-
-
4B-2
(1278)
-
-
-
-
1
-
3
2
-
-
-
-
4C-1
(1458)
-
-
-
-
1
-
-
-
-
-
-
-
4A-1
(1656)
-
-
-
-
5
-
-
-
-
-
-
-
3A-1
: (1764)
-
-
-
-
1
-
-
-
-
-
-
-
AK0036.W51
-------
Table 3.3.2-3A.
Continued.
SPECIES
(depth in meters)
Paractinistola-like
anemone
Unknown gastropod #1
snail?
Paralkhoides
crab
Braided sea pen
sea pen
Unknown Ophiuroid spp. 2
brittlestar
Lophaster furcilliger
seastar
Pteraster tessalatus
seastar
Actinostola-like
anemone
Scotoplanes globosa
sea cucumber
Orange, flat corallimorph
anemone
Aphrodfta
sea mouse
Stylatula spp 2.
sea pen
2A
(72)
-
-
-
-
-
-
-
-
-
-
-
-
2B-3
(85)
-
-
-
-
-
-
-
-
-
-
-
-
2C-1
(85)
-
-
-
-
-
-
-
-
-
-
-
-
MD2-1
(128)
-
-
-
-
-
-
-
-
-
-
-
-
MD1-1
(252)
-
-
-
-
-
-
-
-
•
-
-
-
PC1-1
(495)
-
-
-
-
-
-
-
-
-
-
-
-
MD3-1
(504)
-
-
-
-
-
-
-
-
-
-
-
-
PC2-1
(675)
-
-
-
-
-
-
-
-
-
-
-
-
3B-1
(1008)
-
-
-
•
-
-
-
-
•
-
-
-
3C-1
{1143)
4
-
-
-
-
-
-
-
-
-
-
-
PC3-1
(1170)
-
5
-
-
-
-
-
-
-
-
-
-
4B-2
(1278)
-
-
4
5
-
-
- '
-
-
-
-
-
4C-1
(1458)
-
-
-
-
2
3
4
5
-
-
-
-
4A-1
(1656)
-
-
-
-
-
-
4
-
1
3
-
-
3A-1
(1764)
-
-
-
-
-
-
3.5
-
-
-
3.5
5
AK0036.W51
-------
Table 3.3.2-3B.
Rank Order of Biomass for Demersal Megafauna Collected During Trawl Surveys of Study Areas 2 Through 4 and
Adjacent Sites in Pioneer Canyon (PC) and in "Mid-Depth" (MD) (SAIC 1992b).
SPECIES
(depth in meters)
Metridium
anemone
Cancer magister
Dungeness crab
Octopus rubescens
octopus
Astropecten verrilli
Spiny sand star
Luidia foliata
sand star
Hippasteria spinosa
seastar
Tritonia
snail
Pleurobranchia
opisthobranch gastropod
Parastichopus simpsoni?
sea cucumber
Gorgonocephalus
brittlestar
Allocentrotus fragilis
sea urchin
Panda/us platyceros
spot prawn
2A
(72)
1
2
3
4.5
4.5
-
-
-
-
-
-
-
28-3
(85)
2
1
4.5
-
-
3
4.5
-
-
-
-
-
2C-1
(85)
1
3
5
-
2
-
-
4
-
-
-
-
MOM
(128)
1
2
-
-
5
-
-
-
3
4
-
-
MDM
(252)
-
-
-
-"
4
-
-
-
1
-
2
3
PCM
(495)
-
-
-
-
-
-
-
-
-
-
-
-
MDa-i
(504)
-
-
-
-
-
-
-
-
-
-
-
-
PC2-1
(675)
-
-
-
-
-
-
-
-
-
-
-
-
3&.1
(1008)
-
-
-
-
-
5
-
-
-
-
-
-
3CM
(1143)
-
-
-
-
-
-
-
-
-
-
-
-
PC3-1
(1170)
-
-
-
-
-
-
-
-
-
-
-
-
48-2
(1278)
-
-'
-
-
-
-
-
-
-
-
-
-
4C-1
(1458)
-
-
-
-
-
-
-
-
-
-
-
-
4A-1
(1656)
-
-
-
-
-
-
-
-
-
-
-
-
3A-1
(1764)
-
-
-
-
-
-
-
-
-
-
-
-
AK0037.W5I
-------
Table 3.3.2-3B.
Continued.
SPECIES
(depth irt meters)
Rathbunaster californicus
seastar
Myxoderma platyacanthum
seastar
Pannychia
sea cucumber
Paractinistola-like
anemone
Asteronyx loveni
brittlestar
Chionoecetes tanneri
Tanner crab
Neptunea lyrata
snail
Octopus dofleini
octopus
Moroteuthis robusta
octopus
Bathybembix bairdii
snail
Thrissacanthias penicillatus
seastar
Paralithoides
crab
2A
(72)
-
-
-
-
-
-
-
-
-
-
-
-
2B-3
(85)
-
-
-
-
-
-
-
-
-
-
-
-
2C-1
(85)
-
-
-
-
-
-
-
-
-
-
-
-
MD2-1
(128)
-
-
-
-
-
-
-
-
-
-
-
-
MD1-1
(252)
5
-
-
-
-
-
-
-
-
-
-
-
PCM
(495)
-
1
2
3
4
5
-
-
-
-
-
-
MD3-1
(504)
-
1
-
3
5
2
4
-
-
-
-
-
PC2-1
(675)
-
2
-
-
-
1
5
3
4
-
-
-
3B-1
(1008)
-
-
2
4
-
1
-
-
-
3
-
-
3C-1
{1143)
-
-
-
2
-
1
-
-
-
-
3
4
PC3-1
(1170)
-
-
-
3
-
1
4
-
-
2
-
-
4B-2
(1278)
-
-
3
-
-
1
5
-
-
-
-
2
4C-1
(1458)
-
-
1
-
-
-
-
-
-
-
5
-
4A-1
(1656)
-
-
-
-
-
-
-
-
-
-
-
-
3A-1
(1764)
-
-
1
-
2
-
-
-
-
-
-
-
AK0037.W51
-------
Table 3.3.2-3B.
Continued.
SPECIES
(depth ift meters)
Heterozonias alternates
seastar
Opisthoteuthis California
octopus
Braided sea pen
sea pen
Actinoscyphia-like
anemone
Brown "sweet potato"
sea cucumber
Pteraster tessalatus
seastar
Orange, flat corallimorph
anemone
Scotoplanes globosa
sea cucumber
Heterozonias-like
seastar
Solaster borealis
seastar
2A
(72)
-
-
-
-
-
-
-
-
-
-
2B-3
(85)
-
-
-
-
-
-
-
-
-
-
2C-1
(85)
-
-
-
-
-
-
-
-
-
-
MD2-1
{128}
-
-
-
-
-
-
-
-
-
-
MD1-1
(252)
-
-
-
-
-
-
-
-
-..
-
PCl-1
(495)
-
-
-
-
-
-
-
-
-
-
MD3-1
(504)
-
-
-
-
-
-
-
-
-
-
PCM
(675)
-
-
-
-
-
-
-
-
-
-
3B-1
(1008}
-
-
-
-
-
-
-
-
-
-
3C-1
(1143)
5
-
-
-
-
-
-
-
-
-
PC3-1
(1170)
-
5
-
-
-
-
-
-
-
-
4B-2
(1278)
-
-
4
-
-
-
-
-
-
-
4C-1
(1458)
-
-
-
2
3
4
-
-
-
-
4A-1
(1656)
-
-
-
-
-
3
1
2
4
5
3A-1
(1764)
5
-
-
4
3
-
-
,/
-
-
AK0037.W51
-------
3000 -i
< 2000
h-
O
Ul
X
te.
LJ
m
2
"-' 1000 -
X X
2
B
7
2
2
A
8
5
2
C
8
5
M
0
2
1
2
8
M
D
1
2
5
2
P
C
1
4
9
5
M
D
3
5
0
4
P
C
2
6
7
5
3
B
1
0
0
8
3
C
1
1
4
3
P
C
3
1
1
7
0
4
B
1
2
7
8
4
A
1
4
5
8
3
A
1
6
5
6
4
C
1
7
6
4
TAXAGRP
TRANSECT BY AVERAGE DEPTH (M)
Coelenterates
[\\\N
Echinoderms
Other
L
Crustacea
Molluscs
Figure 3.3.2-5.
Sum of Densities of Megafaunal Invertebrate Species by General Taxonomic Group
Collected During Trawl Surveys by SAIC (1992b) at Each Transect;
Transects Sorted in Order of Increasing Depth.
Average Depth (m) is indicated beneath each transect.
-------
100 -\
90 -
80 -
-70 -
Łj 60 H
S so H
c.
40 -
co
°J 30 H
i 20 H
10 H
o
\v
to
2
B
7
2
2
A
8
5
2
C
8
5
M
D
2
1
2
8
M
D
1
2
5
2
P
C
1
4
9
5
M
0
3
5
0
4
P
C
2
6
7
5
3
B
1
0
0
8
3
C
1
1
4
3
P
C
3
1
1
7
0
4
B
1
2
7
8
4
A
I
4
5
8
3
A
1
6
5
6
4
C
1
7
6
4
TRANSECT BY AVERAGE DEPTH (M)
GROUP
Coelenterates
[\\\N Echinoderms
Other
J
Crustacea
Molluscs
Figure 3.3.2-6. Sum of Biomasses of Benthic Megafaunal Invertebrate Species by General Taxonomic Group
Collected During Trawl Surveys by SAIC (1992b) at Each Transect;
Transects Sorted in Order of Increasing Depth.
Average Depth (m) is indicated beneath each transect.
-------
and 3.83 kg per hectare), while Dungeness crab, octopus, and seastar biomass ranked in the top
five (Table 3.3.2-3B). Some Dungeness crab and market squid (Loligo opalescens) were
collected by SAIC (1992b) in this study area, and represent the only prominent commercial
megafaunal fisheries species. Bence et al. (1992) collected market squid in midwater trawls,
conducted within 30 m of the surface and over depths shallower than 180 m, which is similar in
depth to Study Area 2. Hard-bottom habitats probably occur but were observed infrequently in
this study area; however, sparse occurrences of rocks were observed using an ROV on
Transect 2C-1 (SAIC 1992b).
Study Area 3
Study Area 3 is characterized by relatively moderate to high numbers of megafaunal species
(Figure 3.3.2-4). Densities over the entire study area were low to moderate, ranging from
approximately 200 to 1,000 individuals per hectare (Figure 3.3.2-5). Densities and biomass from
the shallow parts of Study Area 3 (depths between 1,000 m and 1,200 m) were generally higher
than from the deeper part (approximately 1,700 m), including Alternative Site 3, primarily due
to the predominance of Molluscs (Bathybembix bairdii and Neptunia amianta), sea cucumbers
(Pannychia spp.), brittlestar (Asteronyx loveni), seastars, and crustaceans such as Tanner crabs
(Chionoecetes tanneri; Tables 3.3.2-3A and 3.3.2-3B; SAIC 1992b) In the deeper parts of the
study area (Transect 3A-1), Pannychia, Asteronyx loveni, and seastar (Pteraster tessalatus) were
the predominant taxa collected by SAIC (1992b). Hard-bottom substrate (small rock
outcroppings) was observed with an ROV by SAIC (1992b) on Transects 3A-1 and 3B-1 with
sessile invertebrates such as anemones predominating.
Study Area 4
Study Area 4 is characterized by relatively high numbers of megafaunal invertebrate species,
ranging from 19 to 37 (Figure 3.3.2-4). Densities in the shallow parts of this study area (depths
between 1,278 m and 1,458 m) were low to moderate, with densities ranging from 100 to 400
3-133
-------
individuals per hectare (Figure 3.3.2-5). Biomass in the shallow parts ranged from approximately
10 to 25 kg per hectare (Figure 3.3.2-6). Predominant taxonomic groups in the shallow parts of
the study area include echinoderms, cnidarians, and crustaceans (Table 3.3.2-3A). In the deepest
part of the study area (Transect 4C), including the vicinity of Alternative Site 4, densities and
biomass were relatively low (Figures 3.3.2-5 and 3.3.2-6), with echinoderms (e.g., the seastars
Heterozonias and Pteraster and the sea cucumber Scotoplanes) and cnidarians (e.g., anemones)
comprising the predominant taxonomic groups. No hard-bottom substrate was observed using
an ROV (SAIC 1992b) within this study area.
Study Area 5
Study Area 5, surveyed in part by the Navy in 1991 (Nybakken et al. 1992; SAIC 1992a),
represents a deeper survey region (depths primarily between 2,300 m and 3,200 m) than Study
Areas 2, 3, and 4 (depths between approximately 72 m and 1,800 m) surveyed by SAIC (1992b).
Within Study Area 5, (including Alternative Site 5) Nybakken et al. (1992) collected 95 taxa of
megafaunal invertebrates, of which 71 species were identified, including at least five believed to
be species previously unknown to science. Densities in this study area were extremely low
(ranging from a mean of near zero to 270 individuals per hectare); however, predominant taxa
included sea cucumbers, (Molpadia intermedia and Paelopadites confundeus), brittlestars
(Amphiura carchara), seastars, and cnidarians. Biomass was not determined for taxa collected
by Nybakken et al. (1992) in this study area; however, it most likely was extremely low based
on the low densities and small sizes of the organisms.
Primary qualitative differences between results from the EPA study in Study Areas 2, 3, and 4
(SAIC 1992b) and the Navy study (Nybakken et al. 1992; SAIC 1992a) reflect depth-related
trends between shelf (Study Area 2) and upper to middle slope communities (Pioneer Canyon
sites and the shallower portions of Study Areas 3 and 4) compared to lower continental slope
communities (the deeper portions of Study Areas 3 and 4), and the continental rise (Study
Area 5). This conclusion is based on the predominance of very similar megafaunal taxa
3-134
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(Nybakken et al. 1992; SAIC 19925) and fish communities (Cailliet et al. 1992; SAIC 1992b)
at depths from approximately 1,200 m to 3,200 m (i.e., lower slope and rise). For example,
echinoderms (sea cucumbers, brittlestars, and seastars) and cnidarians (primarily seapens) were
predominant in the deep parts of Study Area 3 and 4 (SAIC 1992b), as well as in Study Area 5
(Nybakken et al. 1992). Clearly, these similarities are based partly on upper level taxonomic
comparisons and do not account for other potentially important species density and biomass
differences. Nonetheless, the relative similarity of the deeper communities suggests a broad-scale
pattern that appears to be consistent across the deeper portions of Study Areas 3 and 4 and within
Study Area 5.
Comparisons with Other Studies
Prior to recent studies (SAIC 1992 a,b; Nybakken et al. 1992), knowledge of benthic megafaunal
communities and information concerning the processes that regulate these communities on the
continental slope and rise (from depths of approximately 200 m to 4,000 m depth) has been
limited. Nearly all studies of deeper slope communities in the northeastern Pacific, as well as
those in other continental margins, report depth as a major factor related to changes in the
number of species, abundance, biomass, and size structure of populations (Astrahantseff and
Alton 1965; Alton 1966,1972; Carey 1972,1990; Pereyra 1972; Pereyra and Alton 1972; Carney
and Carey 1976). However, it is clear from these studies that depth-associated physical,
chemical, and biological changes along these depth gradients, and not depth alone, are
collectively responsible for the observed patterns.
SAIC conducted a survey of the northern and central California demersal communities at depths
ranging from 30 to 300 m (Lissner et al. 1989). This study concluded that substrate type (hard
versus soft bottom) and relief were the most important physical factors influencing the biological
communities. Depth was next most important while latitude seemed to be least important. The
influence of substrate type was illustrated by its effect on the number of species. On transects
with 75 to 100% hard substrate, 36-44 taxa were identified. Transects with at least 10% hard
substrate still had 23-30 taxa, whereas transects with less than 10% hard substrate contained only
3-135
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11-14 taxa. Sampling stations were north and south of the LTMS study region and did not
overlap the LTMS areas sampled.
Wakefield's (1990) trawl data off Point Sur, California, indicated invertebrates accounted for
about 35% to 75% of the total catch, based on individual abundances, for each 200 m depth
stratum from 400 m to 1,400 m. This contrasts dramatically with results from SAIC (1992b)
where megafauna only contributed from 3% to 13% of the total individuals caught for the same
depth strata. Also in contrast, the average total biomass of megafauna collected by SAIC (1992b)
at slope depths between 400 m and 1,400 m was approximately 465 kg/ha compared with half
that for the Point Sur area (calculated from Wakefield 1990).
Biomass of megafauna collected on the continental slope and near the Columbia River off the
Oregon coast differ from results obtained by SAIC (1992b) off the California coast. For
example, megafaunal biomass collected by SAIC (1992b) was approximately four times that
reported by Pearcy et al. (1982) for the continental slope off central Oregon. In contrast,
invertebrate biomass in the SAIC (1992b) study was less than 20% of the total near the Columbia
River, off the northern Oregon coast (Pereyra and Alton 1972). These differences may be
significantly influenced by trawl gear selectivity.
Differences in the number of species, density, and biomass of megafaunal invertebrates off
central California (SAIC 1992b) as compared to Oregon (Pereyra and Alton 1972) probably were
related to several factors including gear selectivity, inherent latitudinal differences in the faunas,
and more limited knowledge of taxonomy for many species groups (e.g., cnidarians) off the
central California coast. For example, Pereyra and Alton (1972) noted at least 343 species of
megafauna (including infauna), with an estimated 150 additional species unidentified, from their
study off the Columbia River. This represents considerably higher megafaunal diversity than the
approximately 110 species found by SAIC (1992b).
3-136
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Factors Influencing Community Patterns
The community differences by depth observed by SAIC (1992a,b) and Nybakken et al. (1992)
were generally similar to those suggested by Gage and Tyler (1991) and Wakefield (1990), with
the exception that the "upper slope" was divided for the SAIC (1992b) study into two parts:
upper slope (depths of approximately 200 to 500 m) and middle slope (depths of approximately
500 to 1,200 m).
Sediment Types
In general, sediment types change from relatively coarse-grained in shelf and upper continental
slope habitats (approximately < 500 m) to fine-grained muds on the middle to lower slope
(> 1,000 m) and can have a significant effect on the distribution and abundance of megafauna
(Wakefield 1990; Vercoutere et al 1987). Area-specific studies by SAIC (1992c) concluded that
infaunal distribution corresponded to changes in sediment characteristics. Similarly, SAIC
(1992b) found taxonomic differences in megafauna (at the Genus level) that may be attributed
to broad changes in sediment types within the study region (see Section 3.3.2.1). For example,
seastars (Asteronyx loveni and Myxoderma platyacanthuni) were generally predominant at depths
corresponding to sedimentary changes from sand to sandy mud (see Section 3.2.5.1), while no
distributional trends in epifaunal species composition corresponding to sediment characteristics
were evident at depths greater than 1,000 m.
Changes in sediment types in the Gulf of the Farallones are related to several factors including
the presence of the California Undercurrent, which reaches to a depth of about 600 m. The
California Undercurrent can erode fine-grained sediments (Karlin 1980; Smith 1983) and create
favorable habitats for many megafaunal invertebrate species. Thus, due to its role in defining
erosional and depositional zones on the slope (Wakefield 1990), the boundary of the California
Undercurrent may strongly influence the abundance and distribution of species along this depth
gradient. It is notable that the 600 m boundary of the California Undercurrent is close to the
3-137
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approximate boundary between the upper and middle slope communities (combined fish and
megafauna) defined by SAIC (1992b).
Results from the ROV video and photographic surveys suggest a generally uniform mud bottom
over most transect areas (see Section 3.3.3). Thus, major changes in the sedimentary
environment, as might be associated with community differences, were not evident. However,
the resolution of sediment grain-size differences from the ROV data may not be sufficient to
recognize subtle changes.
The proximity of the study region to waters outflowing from San Francisco Bay also may have
an influence on the diversity of the fish and megafaunal communities. Seasonal changes related
to river runoff, sediments derived from the estuary, and other factors such as organic fluxes may
influence benthic habitat heterogeneity and complexity, leading to changes in species diversity.
For example, the differences in species composition noted by Pereyra and Alton (1972) may be
attributed to runoff by the Columbia River.
Oxygen Minimum Zone
The presence of gradients such as those produced by the oxygen minimum zone (OMZ) may be
responsible for the depth-related patterns of some species on the California continental slope
between approximately 600 and 800 m depths (Wakefield 1990). Perhaps the most striking
distribution related to the oxygen minimum was that of the sea star Myxoderma platyacanthum,
which was the most abundant megafaunal invertebrate in the OMZ, where it was found almost
exclusively. Although there are no relevant physiological studies that have been performed on
this species, it is notable that extensive respiratory structures (papulae), which potentially could
be important in low oxygen environments, are present in high densities over the surface of. this
seastar. Because of the apparent effect of the OMZ on at least some common species, this
boundary may strongly influence the patterns of community distribution noted from the cluster
analyses (see SAIC 1992b Figure 3-12). SAIC (1992c) also found upper slope infaunal
3-138
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communities to be influenced by the OMZ, especially in the 600 to 800 m depth zones where
oligochaetes are present in the fauna and indicative of sites with some partial oxygen stress.
The number of megafaunal invertebrate species tended to increase through the OMZ, perhaps due
to reduced movement and activity (and lesser sensitivity to low oxygen conditions) of most
species (SAIC 1992b). This pattern of increasing number of megafaunal species from the shelf
break towards the middle of the continental slope is similar to general patterns reported from the
western Atlantic (Rex 1981, 1983) and for many continental slope communities (Sanders and
Messier 1969; Haedrick et al. 1980).
Biological Factors
The majority of studies on biological processes have been conducted in intertidal or shallow
subtidal habitats and their applicability to processes influencing deeper water species is unknown.
Biological factors, including competition for space or food (Sebens 1986), predation (Paine and
Vadas 1969; Lubchenco 1978), and larval selectivity and availability (Crisp 1974; Scheltema
1974) may also influence the distribution and abundance of benthic communities within the study
region. Additional studies to evaluate biological processes in deep-water habitats would expand
our understanding of the ecology and interactions of these organisms.
3.3.2.3 Pelagic Invertebrates
This section describes the pelagic invertebrates collected by SAIC (1992b), Nybakken et al.
(1992), and Bence et al. (1992) within the study region. Because they were not specifically
targeted by the EPA or Navy studies, pelagic invertebrates collected during these surveys
represent incidental catches. Midwater trawls by NMFS represent the most comprehensive
database for pelagic species within the general study region.
Pelagic invertebrates include those species capable of movement throughout the water column
and/or just above the bottom. Examples include euphausiids, squid, pteropods, heteropods, and
3-139
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octopuses. Documentation of pelagic invertebrate populations and abundances in the region is
limited. Most of the available information focuses on euphausiids and cephalopods that are either
of commercial importance or are prey items for fish, marine birds, and marine mammals.
Midwater surveys in the region (Bence et al. 1992) and the analyses of commercial fishery
catches (MMS/CDFG Commercial Fisheries Database 1992) indicated that cephalopods were a
predominant pelagic invertebrate group in the study region. Market squid collected in midwater
trawls at depths of approximately 30 m tended to be most abundant in areas less than 180 m in
depth, similar to Study Area 2, while squid abundances in Study Areas 3, 4, and 5 (including
Alternative Sites 3, 4, and 5), were uniformly low (Bence et al. 1992). In contrast, other squids
(not including market squid) had low abundances within Study Area 2 and higher abundances
at depths greater than 1,200 m, corresponding to Study Areas 3, 4, and 5 (Bence et al. 1992).
Euphausiids were patchily abundant throughout the study region and available data do not provide
a clear indication that they were more abundant in any particular study area (Bence et al. 1992).
Because virtually no deep-water pelagic habitats on the Farallon slope have been sampled,
information concerning these pelagic species at similar depths off the central California coast is
important. For example, a combination of deep-water sampling and monitoring of local
commercial fisheries in Monterey Bay resulted in the collection of ten species of previously
unreported cephalopods including Gonatus spp., Berryteuthis anonychus, Chiroteuthis calyx,
Octopoteuthis 'deletron, Valbyteuthis danae, Japetella heathi, and Graneledone spp. (Anderson
1978). Catches from large midwater trawls and commercial anchovy purse-seine hauls analyzed
for pelagic assemblages were dominated by the common market squid Loligo opalescens (Cailliet
et al. 1979). SAIC (1992b) collected seven species of cephalopods, including market squid,
Moroteuthis robusta, Vampiroteuthis infernalis, Benthoctopus spp., Octopus dofleini, O.
rubescens, and Opisthoteuthis californiana. Cephalopods are also a primary prey item for many
marine mammals foraging over the continental shelf (Fiscus 1982; Roper et al. 1984) such as
whales which feed on squid off the central California coast (Fiscus et al. 1989).
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3.3.2.4 Commercially Important Species
The offshore coastal regions of central California support fisheries for a number of epifauna
species including pink shrimp (Pandalus jordani); spot prawn (Pandalus platyceros); four crab
species of the genus Cancer, including Dungeness crab (C. magister); and market squid (Loligo
opalescens; Roper et al. 1984).
Commercially and/or recreationally important species collected within the study region by SAIC
(1992b) included Dungeness crab, market squid, and various species of shrimp; however, all these
species were collected infrequently (primarily as incidentals) and in low abundances.
Assessments of local squid populations have been made to determine fishery size and structure
(Roper et al. 1984; Recksick and Frey 1978) and correlations between oceanographic conditions
and squid catches (Mclnnis and Broenkow 1978). The predominance of squid off the central
coast of California, and their importance as a prey species to marine mammals suggest that these
species are a major component of the pelagic invertebrate community.
Study Area 2, with a maximum depth of approximately 180 m, is likely to support the most
substantial commercial fisheries for both pelagic and demersal invertebrates within the study
region, with species such as pink shrimp, spot prawn, Cancer crabs, and market squid
predominating. Dungeness crab, a significant bottom fishery resource in shallow inshore depths
along the west coast of North America from central California to Southern Alaska (Botsford et
al. 1989), was collected infrequently within Study Area 2 by SAIC (1992b) and Parr et al.
(1988). Market squid populations were most abundant in midwater trawls in the top 30 m of the
water column, over depths less than approximately 180 m, corresponding to similar depths within
Study Area 2 (Bence et al. 1992), although crabs and urchins were the primary megafaunal
species being targeted in Study Area 2, according to the MMS/CDFG Commercial Fisheries
Database (1992). Although MMS/CDFG Commercial Fisheries Database (1992) data also
indicated abalone were taken in Study Areas 2 and 3, these data may be inaccurate and a result
3-141
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of reporting or database tabulation error. Abalone are usually limited to shallow intertidal or
subtidal (less than 30 m) hard-bottom substrate.
In contrast to fishery resources in Study Area 2 and shallower inshore areas, little information
exists regarding commercial invertebrate fisheries in Study Areas 3, 4, or 5. This may be due
to lower fishing effort for invertebrates within Study Areas 3, 4, or 5 by commercial fishermen.
3.3.3 Fish Community
This section describes the fish communities in the study region. Separate sections are included
on demersal fishes (those which live on or near the bottom; Section 3.3.3.1) and pelagic fishes
(those that spend all or part of their life in the water column; Section 3.3.3.2). Also, information
is presented on commercially and/or recreationally important species that inhabit the study region
(Section 3.3.3.3).
3.3.3.1 Demersal Species
This section describes the demersal fishes found in the study region, including Study Areas 2,
3, 4, and 5. Specifically, information is presented on predominant species, density, and biomass
within each study area. Also, details are presented on the rank order of density (Table 3.3.3-1 A)
and biomass (Table 3.3.3-1B) for the top five fishes collected during trawl surveys by SAIC
(1992b) in each study area. A summary overview of demersal fish community characteristics
by study area is presented in Table 3.3.3-2. Because a number of fish species (e.g., rockfishes)
possess both pelagic juvenile and demersal adult stages, juvenile stages of these fishes collected
by SAIC (1992b) and Bence et al. (1992) are discussed in Section 3.3.3.2.
Extensive trawl and remotely operated vehicle (ROV) biological surveys were conducted for the
Environmental Protection Agency (EPA) in Study Areas 2 through 4, at adjacent transects within
Pioneer Canyon, and at "Mid-Depth" transects during September and October 1991 (SAIC 1992b)
and by the Navy in Study Area 5 during July 1991 (Cailliet et al. 1992). Previous trawl studies
3-142
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Table 3.3.3-1A.
Rank Order of Density (number of individuals/hectare) by Increasing Trawl Depth for Demersal Fishes Collected by
SAIC (1992b) During Surveys in Study Areas 2 Through 4 and Adjacent Sites in Pioneer Canyon (PC) and at "Mid-
Depth" (MD).
SPECIES
(depth In meters)
Citharichthys sordidus
Pacific Sanddab
Errex zachirus
Rex Sole
Porichthys notatus
Plainfin Midshipmen
Zalembius rosaceus
Pink Surfperch
Pleuronectes vetulus
English Sole
Genyonemus lineatus
White Croaker
Peprilus simillimus
Pacific Butterfish
Microstomus pacificus
Dover Sole
Sebastes Jordan!
Shortbelly Rockfish
Lyopsetta exilis
Slender Sole
Sebastes saxicola
Stripetail Rockfish
Anoplopoma fimbria
Sablefish
2A
(72)
1
2
3
4
5
—
—
—
—
—
—
—
2B-3
(85)
1
4
—
2
—
3
5
—
—
—
—
—
2C-1
(85)
1
3
—
4
2
—
—
5
—
—
—
—
MD2-t
(128)
—
2
5
—
—
—
—
—
1
3
4
—
MD1-1
(252)
—
—
—
—
—
—
—
1
—
3
2
4
PC1-1
. (495J
—
2
—
—
—
—
—
1
—
—
—
—
MD3-1
(504)
—
—
—
—
—
—
—
1
—
—
—
—
PC2-1
(675)
—
—
—
—
—
—
—
2
—
—
—
3
38-1
(1008)
—
—
—
—
—
—
—
2
—
—
—
4
3C-1
(1143)
—
—
—
—
—
—
—
2
—
—
—
—
PC3-1
(1170)
—
—
—
—
—
—
—
4
—
—
—
5
48-2
(1278)
—
—
—
—
—
—
—
2
— •
—
—
—
4C-1
(1458)
—
—
—
—
—
—
—
—
—
—
—
—
4A-1
(1656)
—
—
—
—
—
—
—
—
—
—
—
—
3A-1
(1764)
—
—
—
—
—
—
—
—
—
—
—
—
AK0038.W51
-------
Table 3.3.3-1A.
Continued.
SPECIES
(depth in meters)
Sebastes diptoproa
Splitnose rockfish
Sebastolobus altivelis
Longspine Thomyhead
Sebastolobus alascanus
Shortspine Thomyhead
Lycodes cortezianus
Bigfin Eelpout
Nezumia stelgidolepis
California Grenadier
Merluccius productus
Pacific Hake
Alepocephalus tenebrosus
California Slickhead
Coryphaenoides acrolepis
Pacific Grenadier
Albatrossia pectoralis
Giant Grenadier
Antimora microlepis
Finescale Codling
Lycenchelys Jordan!
Shortjaw Eelpout
Coryphaenoides filifer
Threadfin Grenadier
2A
(72)
—
—
—
—
—
—
—
—
—
—
—
—
2B-3
(85)
/
—
—
—
—
—
—
—
—
—
—
—
2C-t
P)
—
—
—
—
—
—
—
—
—
—
—
—
MD2-1
(128)
—
—
—
—
—
—
—
—
—
—
—
—
MD1-1
(252)
5
—
—
—
—
—
—
—
—
t—
—
—
PCM
{495}
—
3
4
5
—
—
—
—
—
—
—
—
MD3-1
(504)
—
2
5
3
4
—
—
—
—
—
— '
—
PC2-1
(675)
—
1
4
—
—
5
—
—
—
—
—
—
3B-1
(1008)
—
1
—
—
—
—
5
3
—
—
—
—
3C-1
(1143)
—
1
—
—
—
—
5
3
4
—
—
—
PC3-1
(WO)
—
1
—
—
—
—
2
3
—
—
—
—
4B-2
(1278)
—
4
—
—
—
—
5
1
3
—
—
—
4C-1
(1458)
—
4
—
—
—
2.5
—
1
2.5
5
—
—
4A-1
(1656)
—
4
—
—
—
—
5
1
3
2
—
—
3A-1
(1764)
—
—
—
—
—
—
—
1
5
2
3
4
AK0038.W51
-------
Table 3.3.3-1B.
Rank Order of Biomass by Increasing Trawl Depth for Demersal Fishes Collected by SAIC (1992b) During Surveys
in Study Areas 2 Through 4 and Adjacent Sites in Pioneer Canyon (PC) and at "Mid-Depth" (MD).
SPECIES
(depth in meters)
Citharichthys sordidus
Pacific Sanddab
Errex zachirus
Rex Sole
Pleuronectes vetulus
English Sole
fla/a binoculata
Big Skate
Porichthys notatus
Plainfin Midshipmen
Genyonemus lineatus
White croaker
Zalembius rosaceus
Pink Surfperch
Microstomus pacHicus
Dover Sole
Sebastes Jordan!
Shortbelly Rockfish
Sebastes goodei
Chilipepper
Sebastes saxicola
Stripetail Rockfish
Anoplopoma fimbria
Sablefish
Lyopsetta exilis
Slender Sole
2A
(72)
1
2
3
4
5
—
—
—
—
—
—
—
—
28-3
-------
Table 3.3.3-1B.
Continued.
SPECIES
(depth in meters)
Merluccius productus
Pacific Hake
Sebastolobus alascanus
Shorlspine Thomyhead
Sebastolobus altivelis
Longspine Thomyhead
Raja rhina
Longnose Skate
Lycodes cortezianus
Bigfin Eelpout
Coryphaenoides acrolepis
Pacific Grenadier
Albatrossia pectoralis
Giant Grenadier
Alepocephalus tenebrosus
California Slickhead
Antimora microlepis
Finescale Codling
Bathyraja trachura
Black Skate
Bathyraja abyssicola
Deepsea Skate
Bathyraja rosispinus
Flathead Skate
Coryphaenoides filifer
Threadfin Grenadier
2A
(72)
—
—
—
—
—
—
—
—
—
—
—
—
—
28-3
m
—
—
—
—
—
/
—
—
—
—
—
—
—
2C-t
(85)
—
—
—
—
—
—
—
—
—
—
—
—
—
MD2-1
(128)
—
—
—
—
—
—
—
—
—
—
—
—
—
MDM
(252)
—
—
—
—
—
—
—
—
—
—
—
—
—
PCM
(495)
4
5
—
—
—
—
—
—
—
—
—
—
—
MD3-1
(504)
—
—
3
4
5
—
—
—
—
—
—
—
—
PC2-1
(675)
4
5
3
—
—
—
—
—
—
—
—
—
—
38-1
(1(308)
—
5
3
—
—
4
—
—
—
—
—
—
—
3C-1
(1143)
—
4
5
—
—
—
3
—
—
—
—
—
—
PC3'1
(1170)
—
—
5
—
—
3
—
2
—
—
—
—
—
4B-2
(1278)
—
—
—
—
—
2
3
—
5
—
—
—
—
4C-1
(1458)
—
—
—
—
—
2
1
—
4
3
5
—
—
4A*1
(1656)
—
—
5
—
—
1
2
—
3
—
4
—
—
3A*1
(1764)
—
—
—
—
—
1
2
—
3
—
—
4
5
AK0039.W51
-------
Table 3.3.3-2.
Summary by Study Area of Demersal Fish Community Characteristics.
Survey
Location
Study Area
21
MD
PC
Study Area
31.
Study Area
41
Study Area
*52
Depth Range
Cm)
72-85
128-504
495-1170
1008-1656
1278-1764
2300-3065
Total
Species
29
19
19
16
14
15
Density
(individuals
per hectare)
1500-2500
500-14,000
1500-2500
500-1500
< 100-500
~ 14
Biomass
(kg per hectare)
100-250
220-1200
550-1150
80-400
20-400
Data not
collected
Predominant
Species
Sanddabs
Rex Sole
English Sole
Pink Surfperch
Shortbelly Rockfish
Flatfishes
Sablefish
Skates
Flatfishes
Roc Wishes
Sablefish
Rattails
Thomyheads
Dover Sole
Finescale Codlings
Rattails
Thomyheads
Eelpouts
Rattails
Finescale Codlings
Eelpouts
Snailfishes
Commercially
Important Species
yes
yes
yes
no
yes
yes
yes
no
yes
yes
yes
potential
yes
yes
no
potential
yes
no
potential
no
no
no
1 SAIC 1992b
2 Cailliet et al. 1992
Data are not directly comparable to SAIC (1992b) since different trawl methods were used (beam and small otter trawl versus large otter trawl
for SAIC 1992b).
AK0040.W51
-------
within Study Area 2 also were conducted by KLI (1991). Additional information from midwater
and bottom trawls is summarized in Bence et al. (1992).
Similar to general distributional patterns observed in the study region for invertebrate
communities (see infauna, Section 3.3.2.1; and epifauna, Section 3.3.2.2), demersal fish
communities were differentiated based on depth or depth-related factors in the study region
(Figures 3.3.3-1 and 3.3.3-2). These communities are summarized below:
• A shelf community (from depths of at least 72 to approximately 200 m),
including Study Area 2 and some Mid-Depth transects (Figure 3.3.3-2), was
characterized by relatively high numbers of fish species and abundances
(including commercially/recreationally important species) but relatively low
biomass (Table 3.3.3-2). This community is dominated by sanddabs, English
sole, rex sole, rockfishes (not including thornyheads), pink surfperch, plainfin
midshipman, and white croakers (Table 3.3.3-1 A). Of these, all except pink
surfperch have important commercial value. Figure 3.3.3-1 depicts a typical
shelf community assemblage.
• Upper and middle slope communities (from approximately 200 to 500 m and
500 to 1,200 m depth, respectively), including shallow parts of Study Areas
3 and 4, Mid-Depth, and Pioneer Canyon (Figure 3.3.3-2), were characterized
by moderate numbers of fish species and densities and the highest relative
biomass (including commercially/recreationally important species; Table
3.3.3-2). Fishes collected using trawls and/or observed from ROV records on
the upper slope include rockfishes, flatfishes, sablefish, eelpouts, and
thornyheads (Figure 3.3.3-1). Rockfishes, thornyheads, flatfishes, sablefish,
hake, slickheads, and rattails were collected and observed on the middle slope.
Figure 3.3.3-1 depicts typical upper and middle slope fish assemblages.
• Lower slope communities (from depths of approximately 1,200 m to at least
3,200 m), including the deeper parts of Study Areas 3 and 4 and Study Area 5
(including Alternative Sites 3, 4, and 5), were characterized by relatively low
numbers of fish species, abundance, and biomass (Table 3.3.3-2). This
community is characterized by rattails, thornyheads, finescale codling, and
eelpouts (Figure 3.3.3-1).
Types of depth-related factors recognized as influencing community structure include differences
in the sedimentary environment, the OMZ, and regional current patterns (e.g., summarized in
Wakefield 1990). These factors are discussed in greater detail below.
3-148
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200m-«
600m
1000m
1400m
1800m
2200m
2600m
3000m
CONTINENTAL SHELF
(STUDY AREA 2)
EPIPELAGIC
MESOPELAGIC
Surfperches
Plainfin Midshipman
Flatfishes
Rockfishes
Cusk eel
Butterfishes
Herring
Argentines
Anchovies
Skates
Combfishes
Thornyheads
Sablefish
Hake
Eelpout
Deep-sea smelt
Viperfish
Lanternfishes
Hatchetfishes
Slickheads
Cat Sharks
Rattails
Codlings
Pacific Saury
Juvenile Rockfishes
Bristlemouths
-200m
- 600m
-- 1000m
- 1400m
STUDY
- 1800m
u 2200m
- 2600m
3000m
Figure 3.3.3-1.
Community Assemblages on Continental Shelf and Slope off San Francisco, California,
for Common Fishes Collected in Trawls by SAIC (1992b), Cailliet et al. (1992), and NMFS
(1992) in LTMS Study Areas 2,3,4, and 5.
Taxonomic groups (e.g., families) may represent more than one species. Fishes do not accurately reflect size differences.
Drawings taken from Miller and Lea (1912).
-------
Demersal fish communities within the study region exhibited several distinct patterns related to
the number and type of species, density, and biomass (Tables 3.3.3-2, 3.3.3-1 A, and 3.3.3-IB;
Figures 3.3.3-3 through 3.3.3-5). The numbers of species collected from transects in Study
Area 2 by SAIC (1992b) ranged from 18 to 29 (Figure 3.3.3-3), with flatfishes (such as Pacific
sanddab, Citharichthys sordidus, English sole, Pleuronectes vetulus and rex sole, Errex zachirus),
rockfishes (Sebastes, spp.), and species such as pink surfperch (Zalembius rosaceus) being
abundant (Table 3.3.3-1 A). Similar results were obtained by Bence et al. (1992) and KLI (1991)
in Study Area 2, with Pacific sanddabs, plainfin midshipmen, and pink surfperch predominating.
Fish densities (number of individuals per hectare) were high in Study Area 2 (Figure 3.3.3-4).
Flatfish densities (Table 3.3.3-1A) and biomass (Table 3.3.3-1B) for species such as Pacific
sanddabs and English sole were highest in Study Area 2. However, biomass (kg/ha) in this area
was relatively low (less than approximately 250 kg/ha) due to the presence of numerous small
flatfishes such as Pacific sanddabs and rex sole (Figure 3.3.3-5). Rockfishes (Sebastes spp.), as
a group were most abundant from depths of approximately 180 to 270 m (Bence et al. 1992),
which corresponds to similar depths adjacent to Study Area 2. Pelagic juvenile Dover sole and
adult Pacific hake were collected in midwater trawls within 30 m of the surface and had higher
abundances in Study Area 2 (Bence et al. 1992).
Study Area 3 was characterized by moderate numbers of species (Table 3.3.3-2; Figure 3.3.3-3).
Fish densities (Figure 3.3.3-4) from the shallow parts of Study Area 3 (at depths of
approximately 1,000 to 1,200 m; Transects 3B-1 and 3C-1) were higher than the deeper part (at
depths of approximately 1,700 m; Transect 3A-1) and Alternative Site 3 (SAIC 1992b).
Rockfishes such as thornyheads (Sebastolobus spp.) and flatfishes such as Dover sole, comprised
the highest densities in the shallower parts of this study area, while rattails and finescale codling
represent characteristic species at deeper depths (SAIC 1992b; Bence et al. 1992). Densities of
both thornyheads and Dover sole were high in this study area (Table 3.3.3-1 A). Biomass
decreased in the shallowest to deepest parts of this study area, from 400 to 80 kg/ha, with Dover
sole and sablefish contributing the highest proportion of biomass (Table 3.3.3-IB; Figure 3.3.3-5).
3-150
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37°20' N
LOWER
SLOPE
UPPER (AND MIDDLE) SLOPE
-123° W
Figure 3.3.3-2 Summary of Distribution Patterns of Bent hie Communities (Fishes and Megafaunal Invertebrates)
from Trawl and ROY Studies Conducted in September and October 1991.
Transect start and end coordinated are indicated for trawls (solid lines) and ROV (dots mark coordinates). Study Areas 2,3,
and 4 locations are shown by "2", "3", and "4"; MD=Mid-depth; PC=Pioneer Canyon. Shelf communities are less than or
equal to 200 m; upper slope is 200-500 m; middle slope is 500-1,200 m; and lower slope is greater than 1,200 m.
Shades of blue correspond to areas with similar species composition (dark blue) and areas with less similar species composition
(light blue) based on cluster analysis by SAIC (1992b).
-------
This page intentionally left blank.
Figure 3.3.3-2. Continued.
AK0096
p.2o(2 3-152
-------
30 -
in
LJ
o
LJ
O.
V}
O
o:
UJ
m
2
O
Ui
TAXA
TRANSECT BY AVERAGE DEPTH (M)
^elpouts
1\\\N Other
Rockfish
Sharks/skates
C
—I Flatfish
L V IRattails
y///\ Sablef ish
Figure 3.3.3-3.
Number of Benthic Fish Species by General Taxonomic Group Collected
During Trawl Surveys by SAIC (1992b) by Each Transect;
Transects Sorted in Order of Increasing Depth.
Average depth (m) is indicated beneath each transect.
-------
14000
13000 -
12000 -
u 11000 -
5 ioooo -
9000 -
8000 -
7000 -
6000-
5000 -
4000 -
3000 -
2000 -
1000-
0
o
LJ
I
\
QL
Ul
m
2
Z3
z
z
Ul
o
Ln
2
B
7
2
2
A
8
5
2
C
8
5
M
D
2
1
2
8
M
D
1
2
5
2
P
C
1
4
9
5
M
D
3
5
0
4
P
C
2
6
7
5
3
B
1
0
0
8
3
C
1
1
4
3
P
C
3
1
1
7
0
4
B
1
2
7
8
4
A
1
4
5
8
3
A
1
6
5
6
4
C
1
7
6
4
TRANSECT BY AVERAGE DEPTH (M)
TAXA
Eelpouts
[\\V\1 Other
A Sharks/skates
I////J
Flatfish
RattalIs
Sablefish
Figure 3.3.3-4. Sum of Densities of Benthic Fish Species by General Taxonomic Group
Collected During Trawl Surveys by SAIC (1992b) at Each Transect;
Transects Sorted in Order of Increasing Depth.
Average depth (m) is indicated beneath each transect.
-------
ui
on
o
LJ
I
v\
1200 -i
1100 -
1000 -
900 -
800 -
700-
600 -
500
400 -
300 -
2
O
CD 200 -
100 -
0
2
B
7
2
2
A
8
5
2
C
8
5
M
D
2
1
2
8
M
D
1
2
5
2
P
C
1
4
9
5
M
D
3
5
0
4
P
C
2
6
7
5
3
B
1
0
0
8
3
C
1
1
4
3
P
C
3
1
1
7
0
4
B
1
2
7
8
4
A
1
4
5
8
3
A
1
6
5
6
4
C
1
7
6
4
TRANSECT BY AVERAGE DEPTH (M)
TAXA
1\\\N
Eelpouts
Other
Rockf ish
Sharks/skates
C
V///\
Flatfish
RattaiIs
Sablefish
Figure 3.3.3-5.
Sum of Biomasses of Benthic Fish Species by General Taxonomic Group
Collected During Trawl Surveys by SAIC (1992b) at Each Transect;
Transects Sorted in Order of Increasing Depth.
Average depth (m) is indicated beneath each transect
-------
Slender sole (Lyopsetta exilis) and spotted ratfish (Hydrolagus colliei) were abundant at depths
of approximately 270 to 360 m, suggesting they also might be common in the shallowest parts
of this study area (Bence et al. 1992).
SAIC (1992b) collected the lowest number of species in the deepest part of Study Area 4 and
Alternative Site 4, although this may have been due to problems with sampling gear on one of
the three trawls. In the entire study area, rattails (Coryphaenoid.es spp.) comprised the majority
of the trawl fish catch. Densities of fishes varied, but were usually less than 500/ha
(Figure 3.3.3-4). At depths greater than approximately 1,500 m (e.g., Transect 4C), the numbers
of fish species, densities, and biomass were extremely low. The highest biomass contribution
at these deeper depths was from rattails and slickheads (Table 3.3.3-IB; Figure 3.3.3-5). Bence
et al. (1992) indicated thornyheads (Sebastolobus spp.) were most abundant at depths between
700 to 900 m. This suggests thornyheads might be common in the shallow parts of Study Area
4 (Bence et al. 1992), while rattails were most abundant in the deep portions of Study Areas 3
and 4 and in Study Area 5 (including Alternative Sites 3, 4, and 5).
Study Area 5, surveyed by the Navy in 1991 (Cailliet et al. 1992), was dominated by rattails,
eelpouts (Zoarcidae), and morids (Antimora microlepis). Fish density in this study area was low
(e.g., 207/ha). These general results are very similar to those observed for the deep slope
communities in Study Areas 3 and 4 at depths greater than approximately 1,200 m, even though
the trawl used by SAIC (1992b) was a large commercial-sized otter trawl, while Cailliet et al.
(1992) used a small beam trawl and a small otter trawl. Within Study Area 5, Cailliet et al.
(1992) collected 15 species of fishes, of which rattails, eelpouts, and finescale codling were
predominant.
Based on the differences in sampling methods, as noted above, quantitative comparisons between
Study Areas 2 through 4 and Study Area 5 do not appear to be appropriate. Primary qualitative
differences between results from SAIC (1992b) surveys in Study Areas 2, 3, 4, Mid-Depth, and
Pioneer Canyon and Cailliet et al. (1992) surveys in Study Area 5 reflect depth-related trends
3-156
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between shelf (Study Area 2) and upper to middle slope communities (Pioneer Canyon sites and
the shallower portions of Study Area 3) compared to lower slope communities (Study Area 4,
the deeper portion of Study Area 3, and Study Area 5). This conclusion is based on the
predominance of very similar fish taxa from depths of approximately 1,200 to 3,200 m (i.e.,
lower slope) as compared to the shallower communities. For example, lower slope fish
communities from both studies are characterized by rattails, eelpouts, and finescale codlings.
Clearly, these similarities and differences are based partly on upper level taxonomic comparisons
and do not account for other potential species density and biomass differences. Nonetheless, the
relative "sameness" of the deeper communities suggests a broad-scale pattern that is consistent
across the deeper portions of Study Areas 3 and 4 and within Study Area 5. This similarity is
also evident from Bence et al. (1992) surveys. Although both midwater and demersal trawls
were used, results similar to SAIC (1992b) and Cailliet et al. (1992) in species composition were
obtained by the NMFS surveys.
Comparisons With Other Studies
Several studies from California to the Pacific Northwest show variations with depth among major
fish groups. For shallow depths on the continental shelf and upper continental slope, flatfishes,
including Bothidae (e.g., sanddabs) and Pleuronectidae (e.g., rex sole and Dover sole), account
for the greatest biomass in most studies. Fishes such as flatfishes, including Dover sole, rex sole,
and in some cases Pacific sanddabs (SAIC 1992b; Bence et al. 1992), were also dominant on the
shelf and upper slope off Point Sur (Wakefield 1990), offshore from the Columbia River (Pearcy
et al. 1982), and over most trawl locations along the coast of central California which were
sampled by NMFS (Butler et al. 1989). Smaller individuals of these flatfish species usually were
most abundant at the shallowest depths and larger individuals were most abundant on the
continental slope (SAIC 1992b, Figures C-6 , C-5 , and C-2 ).
Comparisons of shelf fish communities based on abundance data from SAIC (1992b) and KLI
(1991) indicated that flatfishes, pink surfperch, plainfin midshipman, and rockfishes made up the
3-157
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top species or taxonomic groups collected by both studies within the study region. Comparisons
of upper slope fish communities at depths between approximately 300 to 600 m with studies by
Wakefield (1990) and Cross (1987) at depths between 600 to 1,600 m indicated that flatfishes,
rockfishes, and eelpouts ranked in the top five, suggesting that species compositions were similar
between both of these studies over the same depth intervals. Finally, on the lower slope (at
depths greater than 1,200 m) thornyheads, rattails, eelpouts, and finescale codling ranked high
in all studies (SAIC 1992b; Wakefield 1990).
Factors Influencing Community Patterns
Fish community structure within the study region can be influenced by depth or depth-related
factors such as the sedimentary environment, regional current patterns, and the OMZ.
Several factors, including the presence of the California Undercurrent, which reaches to a depth
of about 600 m, may contribute to changes in sediment types in the Gulf of the Farallones. Thus,
due to its role in defining erosional and depositional zones on the slope (Wakefield 1990), the
boundary of the California Undercurrent may also influence the abundance and distribution of
demersal fishes along this depth gradient. It is notable that the 600 m boundary of the California
Undercurrent is close to the approximate boundary between the upper and middle slope
communities defined by SAIC (1992b).
The proximity of the study region to the outflow from San Francisco Bay also may have an
influence on the diversity of the fish communities within the study region. Seasonal changes
related to river runoff, sediments derived from the estuary, and other factors such as organic
fluxes, may influence benthic habitat heterogeneity and complexity, leading to changes in species
diversity. The only other west coast study of slope fishes offshore of a large estuary or river is
Alton's (1972) study off the Columbia River.
In addition to sedimentary effects on fish communities, the presence of gradients such as those
produced by the OMZ may be responsible for the depth-related patterns of some species found
3-158
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on the California continental slope at depths between approximately 600 m and 800 m
(Wakefield 1990). Oxygen minima usually underlie surface waters having high primary
production or other high inputs of organic material (e.g., upwelling zones along the coast of
California). Active species, such as many types of fishes, may be unable to withstand low
oxygen concentrations. Although few studies have been conducted, there is some evidence which
indicates that species inhabiting the OMZ are well adapted to low oxygen environments. Some
mid-water species in this zone have the ability to regulate oxygen consumption (Childress 1975);
dominant species of demersal fishes, such as mornyheads, have several biochemical adaptations
which allow them to thrive on the continental slope (reviewed in Wakefield 1990). All of these
physical factors may contribute to the overall structure of fish communities within the study
region.
3.3.3.2 Pelagic Species
This section describes pelagic species of fishes collected primarily using midwater and plankton
trawls by NMFS in the study region. Because surveys by SAIC (1992b) and Cailliet et al. (1992)
targeted demersal fish species, most of the pelagic fishes collected during these surveys
represented incidental species. However, the families of pelagic fish species collected by SAIC
(1992b) and Bence et al. (1992) are similar to other studies in comparable marine zones (Moyle
and Cech 1988). Bence et al. (1992) is the most comprehensive data available on pelagic fish
species in the study region. Results from Bence et al. (1992) are from evaluated CalCOFI
ichthyoplankton surveys (mainly the upper 210 m of the water column), NMFS ichthyoplankton
surveys (maximum 200 m wire out) and NMFS midwater trawls for juvenile rockfishes (depths
to 30 m).
The surface waters of the ocean to depths of approximately 200 m (epipelagic zone) represent
an enormous, although relatively featureless, habitat for fishes (Moyle and Cech 1988).
Epipelagic zone waters are typically well lighted, well mixed, and capable of supporting actively
photosynthesizing algae. At depths between 200 and approximately 1,000 m (mesopelagic zone),
light decreases rapidly as does temperature and dissolved oxygen concentrations, while pressure
3-159
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increases. At depths greater than 1,000 m (bathypelagic zone), conditions are characterized by
complete darkness, low temperature, low oxygen levels, and great pressure. Each of these zones
is distinguished by characteristic fish assemblages.
Epipelagic fishes can be distinguished based on two ecological types. Oceanic forms are those
that spend all or part of their life in the open ocean away from the continental shelf, while neritic
forms spend all or part of their life in water above the continental shelf (Moyle and Cech 1988).
Typical epipelagic species include fast-moving swimmers such as tunas, mackerels, and salmon,
as well as schooling baitfish such as herring, anchovy, and juvenile rockfishes. To date,
information exists for epipelagic fishes over the continental shelf; however, little information
exists for epipelagic fishes collected in Study Areas 3, 4, or 5. Epipelagic species collected by
SAIC (1992b) included the Pacific herring, Northern anchovy, medusafish, Pacific sardine, Pacific
mackerel, Pacific saury, Pacific argentines, and juvenile rockfishes, while Bence et al. (1992)
collected approximately 140 species in midwater trawls including juvenile rockfishes, Pacific
herring and Northern anchovy. Although these studies did not target epipelagic fishes, all of
these species were collected in Study Area 2 and most are commercially important. Juvenile
rockfishes represent an important part of both commercial and recreational fisheries along the
entire Pacific coast (Bence et al. 1992). Juvenile rockfishes, such as the shortbelly rockfish
(Sebastes jordani) have been shown to be an important prey item for many seabirds (Ainley and
Boekelheide 1990), and for fishes such as chinook salmon, lingcod, and other rockfish species
(Chess et al. 1988). Some of the pelagic species collected by SAIC (1992), Cailliet et al. 1992,
and Bence et al. (1992) are shown by depth zone in Figure 3.3.3-1.
Mesopelagic fishes comprise the majority of incidental fishes collected by SAIC (1992b) and
Cailliet et al. (1992) in the study region. Most of these species undergo vertical migrations, often
moving into the epipelagic zone at night to prey on plankton and other fishes (Moyle and Cech
1988). Typical mesopelagic species collected in Study Areas 3 and 4 at depths between 100 to
1,000 m by SAIC (1992b) and Bence et al. (1992) included deep-sea smelts (Bathylagidae),
lanternfishes (Myctophidae), and viperfishes (Chauliodontidae; Figure 3.3.3-1). In Study Area 5,
3-160
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Cailliet et al. (1992) also collected six species of mesopelagic fishes, most of which were from
the same families Bathylagidae, Myctophidae, Chauliodontidae, and Sternoptychidae.
Bathypelagic species, in contrast to mesopelagic fishes, are largely adapted for a sedentary
existence in a habitat with low levels of food and no light (Moyle and Cech 1988). SAIC
(1992b) collected bathypelagic fishes such as blackdragons (Idiacanthidae), dragonfish
(Melanostomiidae), and tubeshoulders (Searsiidae) primarily in the deeper parts of Study Areas
3 and 4 at depths greater than 1,000 m, while bathypelagic fishes collected by Cailliet et al.
(1992) in Study Area 5 included lanternfishes (Myctophidae), deep-sea smelts (Bathylagidae),
hatchetfishes (Sternoptychidae), and viperfishes (Chauliodontidae). Most of the species found
to occupy the bathypelagic zone also can be collected in the mesopelagic zone during vertical
migrations. A typical bathypelagic fish assemblage is shown in Figure 3.3.3-1. Bathypelagic
fishes collected by Bence et al. (1992) included deep-sea smelts (Bathylagidae) and lanternfishes
(Myctophidae).
3.3.3.3 Commercially and Recreationally Important Species
This section describes the commercially and recreationally important species of fishes in the
study region including those collected by trawls from EPA (SAIC 1992b) and Navy studies
(Cailliet et al. 1992), as well as information summarized in Bence et al. (1992), unpublished
California Department of Fish and Game (CDFG) Catch Block Data as provided by the Minerals
Management Service (MMS) and Battelle (1989). Although some information is presented from
recreational fisheries within the study region, the majority of fish species discussed in this section
represent commercial landings.
Several of the abundant species collected within the study areas are of commercial importance.
In particular, SAIC (1992b) collected various species of flatfishes (Dover sole, rex sole, sanddabs,
English sole, and Pacific halibut), rockfishes (splitnose, shortbelly, chilipepper, boccacio, and
thornyheads) and sablefish, that are currently targeted by commercial fisheries. The most
common fishes taken by recreational fishermen within the study region include salmon, tunas,
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mackerel, and rockfishes (CDFG Recreational Fisheries Database 1992). A summary of common
commercially and recreationally important species within the LTMS study areas is presented in
Table 3.3.3-3. Additional information concerning commercial and recreational fisheries is
presented in Section 3.4.1.
Flatfishes
In Study Area 2, commercially important species of flatfishes collected by SAIC (1992b), Bence
et al. (1992), and KLI (1991) collected Dover sole, rex sole, Pacific sanddabs, English sole,
petrale sole, and Pacific halibut (Table 3.3.3-3). However, it is notable that Pacific halibut were
collected only rarely and primarily in Study Area 2. Bence et al. (1992) indicate that slender
sole were most abundant between 270-360 m depth, suggesting they might be abundant in the
shallowest portions of Study Area 3. In the shallow parts of Study Areas 3 and 4, two species
of flatfishes (Dover sole and deep-sea sole) were collected by SAIC (1992b). Of these two
species, only Dover sole represents a commercially important flatfish species. No flatfishes were
collected by SAIC (1992b) in the deeper part of Study Areas 3 and 4. Dover sole collected
commercially at depths greater than 800 m have high water content which makes them less
valuable to commercial fishermen under current conditions (Bence et al. 1992).
Rockfishes
Rockfishes such as splitnose rockfish, shortbelly rockfish, boccacio, chilipepper, stripetail
rockfish, and thornyheads are commercially or recreationally important. Rockfishes (not
including thornyheads), found primarily in Study Area 2 by SAIC (1992b) and Bence et al.
(1992), were one of the most abundant and species-rich groups collected on the continental shelf.
Juvenile rockfishes had relatively high seasonal abundances inshore (Study Area 2) and in the
deep parts of Study Area 5, while lower seasonal abundances were found in the deep parts of
Study Areas 3 and 4 (Bence et al. 1992). MMS/CDFG Commercial Fisheries Database (1992)
indicated rockfishes (not including thornyheads) were the predominant species collected
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Table 3.3.3-3.
Summary of Common Commercially and Recreationally Important Fishes Within the LTMS Study Areas.
Information is Based on SAIC (1992b), Cailliet et al. (1992), Bence et al. (1992), MMS/CDFG Commercial Fisheries Database (1992),
CDFG Recreational Fisheries Database (1992), and KLI (1991). Adults are indicated by (A), Juveniles by (J), and Not Specified as
A or J by (NS).
Common Name
Northern Anchovy
Pacific Herring
Pacific Sardine
Pacific Hake
Shortbelly Rockfish
Chilipepper Rockfish
Boccacio
Widow Rockfish
Yellowtail Rockfish
Thornyheads
Sablefish
Lingcod
Pacific Sanddab
Rex Sole
2
(72-85 m)
A/J
A
A
A/J
A/J
A/J
A/J
A
A
A/J
A/J
A/J
A/J
3 "Shallow"
(1,008-1, 143m)
J
A/J
J
J
J
J
A/J
A
J
3 "Deep"
(1,656 m)
J
A/J
J
J
J
J
A/J
J
4
(1.278- 1,764m)
J
A/J
J
J
J
J
A/J
A
J
5
(2,300-3,065 m)
A
A/J
J
J
J
J
ON
AK0041.W51
-------
Table 3.3.3-3.
Continued.
Common Name
California Halibut
English Sole
Dover Sole
Petrale Sole
Rattails (potential fishery)
Salmon
Tunas
Sharks/Skates/Rays
Hagfish
White Croaker
2
(72-85 m)
A
A
A/J
A
NS
NS
A
A
3 "Shallow"
(1,008- 1,1 43m)
A
A
A
3 "Deep"
(1,656 m)
A
A
4
(1,278-1 ,764m)
A
A
A
5
(2.300-3,065 m)
J
A
ON
AK0041.W5I
-------
commercially in Study Area 2, while rockfishes (including thornyheads) were targeted in the
shallow parts of Study Areas 3 and 4. Of the 16 species of rockfishes collected by SAIC
(1992b), only two species, the thornyheads Sebastolobus altivelis and 5. alascanus, were abundant
on the middle and lower continental slope (Study Areas 3 and 4). However, thornyheads
accounted for approximately 25% to 50% or more of the total abundance or biomass of the upper
to middle slope fishes collected by SAIC (1992b) and other studies (Wakefield 1990; Butler et
al 1989; Pearcy et al. 1982; Alton 1972). Thornyheads collected by Bence et al. (1992) were
most abundant at depths between 700 and 900 m, corresponding primarily to the shallow parts
of Study Area 3 (Table 3.3.3-3).
Sablefish
Sablefish commonly ranked third in biomass of the trawl-collected fishes, both along the
California coast (SAIC 1992b; Wakefield 1990; Butler et al. 1989) and offshore Oregon and
Washington (Pearcy et al. 1982; Alton 1972). Sablefish adults and juveniles occur on the
continental shelf (Study Area 2 and adjacent sites; Table 3.3.3-3), but adults tend to be highest
in abundance and biomass on the upper to middle slope (at depths from approximately 200 to
1,200 m; shallow parts of Study Areas 3 and 4), particularly off the Oregon coast where they
accounted for approximately 75% of the total fish biomass at depths between approximately
500 to 1,000 m (Alton 1972). Their abundance is somewhat lower (10% to 25% of the total fish
biomass) off California at middle slope depths (SAIC 1992b; Wakefield 1990; Butler et al. 1989).
SAIC (1992b) found that sablefish densities were highest at depths between 200 to 500 m.
Sablefish are known to inhabit depths of up to 1,800 m (Miller and Lea 1972) and can reach
lengths to one meter. Juvenile sablefish can often be found at or near the surface, while larger
adults occupy deeper depths (Cailliet et al. 1988).
3-165
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Rattails
Rattails, such as the Pacific grenadier and the giant grenadier (Albatrossia pectoralis), dominated
the deepest sampling depths (at depths greater than approximately 1,200 m) within Study Areas
3 and 4 and Study Area 5 (SAIC 19925; Cailliet et al. 1992; Bence et al. 1992; Eschmeyer and
Herald 1983). Rattails are commercially important in many parts of the world; however, these
fishes have been lightly exploited along the Pacific Coast due to the difficulties of deep-water
trawling in the region. (Matsui et al. 1990). For example, some rattails are landed in California
which are caught as part of the deep-water Dover sole fishery (Oliphant et al. 1990). Rattails
are currently fished in Alaska as an alternative fishery to the declining pollock fishery (Jacobson
1991; Matsui et al. 1990).
Other Species
Other fishes with commercial value (Table 3.3.3-3), including hagfish, are utilized primarily for
their skin. In Study Area 3, SAIC (1992b) collected only a few black hagfish (Eptatretus deanii).
Low abundances of hagfish collected by SAIC (1992b) is probably due to gear selectivity and
avoidance of nets due to their burrowing. Additional information concerning commercially and
recreationally targeted species such as tunas, mackerels, and salmon are discussed in
Section 3.4.1.
3.3.4 Marine Birds
This section presents information on marine birds of the study region. Information on the
distribution, abundance, and ecology of key representative species is presented in Section 3.3.4.1.
A summary of the birds' usage of the LTMS study areas is presented in Section 3.3.4.2.
Marine birds are defined as those species that obtain most of their food from the ocean and are
found over water for more than half of the year (Briggs et al. 1987). The Gulf of the Farallones
3-166
-------
is the most important marine bird breeding area on the West Coast of the United States (Sowls
et al. 1980). Many of the 74 species of birds recorded by Briggs et al. (1987) off the California
coast occur in the Gulf of the Farallones during their migration and/or breeding seasons. The
Farallon Islands and vicinity are used throughout the year by some 350,000 marine birds of 122
species (Ainley and Boekelheide 1990). The islands support the world's largest breeding colonies
of ashy storm-petrels (Oceanodroma homochroa, 85% of the world population), Brandt's
cormorants (Phalacrocorax pennicilatus, 10% of the world population), and western gulls (Lams
occidentalis, 50% of the world population) (DeSante and Ainley 1980; Ainley and Boekelheide
1990). Additionally, an estimated one million sooty shearwaters (Puffinus griseus) use the Gulf
of the Farallones, especially during their breeding season from March to July (DeSante and
Ainley 1980; Ainley et al. 1987).
Studies of marine birds near the Farallon Islands have been conducted for over a century. More
recent studies emphasize the biology of twelve species that nest on the Farallon Islands (Ainley
and Boekelheide 1990) and the distributions of birds that forage in the Gulf of the Farallones
(Briggs et al. 1987). In June of 1985 through 1991, the Point Reyes Bird Observatory (PRBO)
conducted surveys that covered the general study region, including LTMS Study Areas 2 through
5 (Ainley and Allen 1992). Data from these surveys provide a long-term record of the
distribution of marine birds during the breeding season, although no comparable studies were
conducted during other seasons. Five additional surveys were conducted by EPA (Jones and
Szczepaniak 1992) during all seasons over a one year period, using methods similar to those used
by PRBO. However, this study was limited in duration. Neither study provided uniform
coverage of the four LTMS study areas. However, collectively they provide sufficient data to
characterize the marine bird communities of the region.
Ainley and Allen (1992) list a total of 63 marine bird species which occur regularly in the study
region (i.e., are present each year, either year-round or seasonally) or have special status (i.e.,
species that are threatened, endangered, or of special concern) (Table 3.3.4-1). Of these 63
species, 14 are breeding species, 37 are seasonal visitors, and 12 are passage migrants.
3-167
-------
Table 3.3.4-1.
Species and General Characteristics of Marine Birds Observed Off California in the Vicinity of the Gulf
of the Farallones.
Those Species Having Legal Status (Special Concern*, Threatened**, or Endangered***) Are Shown in Bold.
Species are listed according to their occurrence within the study region, such as breeding, seasonal visitor, or passage migrant, and
alphabetically by common name within these groups. Relative abundances refer to the following: Abundant = over 25,000 individuals,
Common = between 1,000-25,000 individuals, Uncommon = between 100-1,000 individuals, and Rare = up to 99 individuals. Habitat
areas refer to occurrences over the following water depths: shelf = < 200 m, slope = 200-1999 m, pelagic = > 1999 m.
Primary source: Ainley and Allen (1992)
Scientific
Name
Pandion haliaetus"'
Oceanodroma homochroa
Phalacrocorax pennicilatus
Ptychoramphus aleuticus
Una aalge
Phalacrocorax auritus
Oceanodroma leucorhoa
Brachyramphus
marmoratus"
Phalacrocorax pelagicus
Falco peregrinus"*
Cepphus columba
Cerorhinca monocerata
Common
Mame
American Osprey
Ashy Storm-petrel
Brandt" s Cormorant
Cassin's Auklet
Common Murre
Double-crested
Cormorant
Leach's Storm-petrel
Marbled Murrelet
Pelagic Cormorant
Peregrine Falcon
Pigeon Guillemot
Rhinoceros Auklet
Occurrence
Vithlrj Study
Region
Breeding
Breeding
Breeding
Breeding
Breeding
Breeding
Breeding
Breeding
Breeding
Breeding
Breeding
Breeding
Seasonal
Status
Year-round
Year-round
Year-round
Year-round
Year-round
Summer
Summer
Year-round
Year-round
Year-round
Summer
Year-round
Relative
Abundance
Uncommon
Common
Abundant
Abundant
Abundant
Uncommon
Uncommon
Rare
Common
Rare
Common
Abundant
Predominant Habitat
Shelf
Pelagic
Shelf
Slope
Shelf, slope
Shelf
Pelagic
Shelf
Shelf
Shelf, slope
Shelf
Shelf, slope, pelagic
0\
oo
AK0042.W51
-------
Table 3.3.4-1.
Continued.
Setentie
Name
Fratercula cirrhata
Lams occidentalis
Brachyramphus antiguus
Mellanita nigra
Oceanodroma me/an/a
Diomedea nigripes
Rissa tridactyla
Puffinus opisthomelas
Pelecanus occidentalis"'
Larus californicus
Sterna caspia
Gavia inmer
Pterodroma cooki
Podiceps aechmophorus
Common ;
$fem& \
Tufted Puffin
Western Gull
Ancient Murrelet
Black Scoter
Black Storm-petrel
Black-footed Albatross
Black-legged Kittiwake
Black-vented Shearwater
Brown Pelican
California Gull
Caspian Tern
Common Loon
Cook's Petrel
Eared Grebe
Occurrence
Wltti* Study
Region
Breeding
Breeding
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
•Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal
Status
Year-round
Year-round
Winter
Winter
Winter
Summer
Winter
Winter
Winter
Winter
Winter
Winter
Summer
Winter
Relative
Abundance
Uncommon
Abundant
Uncommon
Uncommon
Irregular (numerous
at sporadic
intervals)
Common
Common
Irregular (numerous
at sporadic
intervals)
Common
Abundant
Uncommon
Uncommon
Uncommon
Uncommon
Predominant Habitat
Slope
Shelf, slope
Shelf
Shelf
Pelagic
Slope, pelagic
Slope, pelagic
Shelf, slope
Shelf
Shelf, slope
Shelf
Shelf
Pelagic
Shelf
s
AK0042.WS1
-------
Table 3.3.4-1.
Continued.
ScfenSfe
Name
Sterna elegans
Oceanodroma furcata
Sterna forsteri
Larus glaucescens
Laws heermanni
L argentatus
Fratercula comiculata
Podiceps nigricollis
Diomedea immutabilis
Larus canus
Pterodroma ultima
Fulmaius glacialis
Stercorarius parasiticus
Puffinus creatopus
Stercorarius pomarinus
Common !
Name
Elegant Tern
Fork-tailed Storm-petrel
Footer's Tern
Glaucous-winged Gull
Heermann's Gull
Herring Gull
Homed Puffin
Horned Grebe
Laysan Albatross
Mew Gull
Murphy's Petrel
Northern Fulmar
Parasitic Jaeger
Pink-footed Shearwater
Pomarine Jaeger
Occurrence
WfthlR Study
Region
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal
Status
Winter
Winter
Year-round
Winter
Winter
Winter
Summer
Winter
Winter
Winter
Summer
Winter
Winter
Summer
Winter
Relative
AtKPttence
Common
Irregular (numerous
at sporadic
intervals)
Common
Common
Common
Common
Uncommon
Uncommon
Uncommon
Uncommon
Uncommon
Abundant
Uncommon
Common
Uncommon
Predominant Habitat
Shelf
Pelagic
Shelf
Shelf, slope
Shelf
Slope, pelagic
Slope, pelagic
Shelf
Slope, pelagic
Shelf
Pelagic
Slope, pelagic
Shelf, slope, pelagic
Shelf, slope
Shelf, slope, pelagic
AK0042.W51
-------
Table 3.3.4-1.
Continued.
ScfenSfe
Name
Mergus senator
Gavia stellata
Larus delawarensis
Diomedea albatrus*"
Puffinus tenuirostris
Puffinus griseus
Catharacta maccormicki
Larus thayeri
Aechmophorus occidentalis
Endomychura hypoleuca*
Gavia pacifica
Sterna paradisaea
Branta bemicla
Larus Philadelphia
Puffinus bulleri
Sterna hirundo
Stercorarius longicaudus
Common
Name
Red-throated Merganser
Red-throated Loon
Ring-billed Gull
Short-tailed Albatross
Short-tailed Shearwater
Sooty Shearwater
South Polar Skua
Thayer's Gull
Western Grebe
Xantus' Murrelet
Arctic (Pacific) Loon
Arctic Tern
Black Brant
Bonaparte's Gull
Bullet's Shearwater
Common Tern
Long-tailed Jaeger
Occurrence
Within Study
Region
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Seasonal Visitor
Passage Migrant
Passage Migrant
Passage Migrant
Passage Migrant
Passage Migrant
Passage Migrant
Passage Migrant
Seasonal
Status
Winter
Winter
Winter
Winter
Winter
Summer
Summer
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Relative
Abtusdance
Uncommon
Uncommon
Common
Rare
Uncommon
Abundant
Rare
Uncommon
Abundant
Rare
Abundant
Common
Abundant
Abundant
Common
Uncommon
Rare
Predominant Habitat
Shelf
Shelf
Shelf
Shelf, slope
Shelf, slope
Shelf, slope
Shelf, slope, pelagic
Slope, pelagic
Shelf
Slope, pelagic
Shelf, slope
Slope, pelagic
Shelf
Shelf
Slope, pelagic
Shelf, slope
Slope, pelagic
U)
AK0042.W51
-------
Table 3.3.4-1.
Continued.
to
Scfentife
Name
Phalaropus fulicarius
Phalaropus lobatus
Lams sabini
Mellanita perspicilata
M. fusca
Common ;
IfeRie :
Red Phalarope
Red-necked Phalarope
Sabine's Gull
Surf Scoter
White-winged Scoter
Occurrence
W» Study
Region
Passage Migrant
Passage Migrant
Passage Migrant
Passage Migrant
Passage Migrant
Seasonal
Status
Winter
Winter
Winter
Winter
Winter
Relative
Aiflpdanc©
Abundant
Abundant
Uncommon
Abundant
Abundant
fffidorajnapt Habitat
Shelf, slope, pelagic
Shelf
Pelagic
Shelf
Shelf
AKOCM2.W51
-------
The distribution, abundance, and ecology of ten key species is described in this section as
representative of the range of natural history patterns that occur within the four study areas and
which potentially could be affected by dredged material disposal activities. Special status species
are discussed in more detail in Section 3.3.6. Because of the importance of the Gulf of the
Farallones to many marine bird species, one or more of the following criteria were used to select
these ten key species:
• Species that breed in the area or which occur year-round or are common to
abundant within the study region;
• Species having a narrow geographical range with population centers located
in the Gulf of the Farallones; and
• Species which forage in shelf, slope, or pelagic areas similar to those of the
LTMS study areas.
Based on these criteria, the following ten species were selected: ashy storm-petrel, Brandt's
cormorant, western gull, common murre (Uria aalge), pigeon guillemot (Cepphus columbd), sooty
shearwater, Cassin's auklet (Ptychoramphus aleuticus), rhinoceros auklet (Cerorhinca
monocerata), pink-footed shearwater (Puffinus creatopus), and tufted puffin (Fratercula cirrhata)
(Table 3.3.4-2). With the exception of the sooty and pink-footed shearwaters, which occur in
high abundances within the LTMS study areas during the summer (Briggs et al. 1987; Jones and
Szczepaniak 1992), all of these species breed within the Gulf of the Farallones. Other marine
bird species recorded in the Gulf of the Farallones, including seasonal visitors and passage
migrants, are listed with their estimated densities in Jones and Szczepaniak (1992) and Ainley
and Allen (1992).
Density estimates of all marine bird species surveyed during June are presented for the years
1986, 1987, and 1991 (Figures 3.3.4-1 through 3.3.4-3) (Ainley and Allen 1992). These years
represent a broad range in different foraging conditions, based on pelagic juvenile rockfish
abundance, from poor (1986) to good (1987) to intermediate (1991) rockfish years. Ainley and
3-173
-------
Table 3.3.4-2.
Relative Densities of the Ten Key Marine Bird Species Within the
Four LTMS Study Areas.
Data from A (Ainley and Bockelheide 1990); B (Ainley and Allen 1992); and C (Jones
and Szczepaniak 1992).
Ashy storm-petrel
Brandt's cormorant
Western gull
Common murre
Pigeon guillemot
Sooty shearwater
Cassin's auklet
Rhinocerus auklet
Pink-footed
shearwater
Tufted puffin
Study Area 2
A
N
N
L
LtoM
N
LtoH
L
H
*
N
B
N
L
M
L
N
LtoH
M
M
LtoH
L
C
N
N
LtoM
L
N
L
L
M
N
N
Study Area 3
A
LtoH
N
L
LtoM
N
LtoH
LtoH
H
*
N
B
L
N
L
L
L
L
L
L
L
N
C
L
N
L
N
N
LtoH
L
L
M
N
Study Area 4
A
*
*
*
*
*
*
*
*
*
*
8
L
N
N
N
N
L
L
L
N
N
C
N
N
L
N
N
L
L
L
L
N
Study Area 5
A
M
N
L
MtoH
N
MtoH
LtoH
LtoM
*
L
B
L
N
L
M
N
M
M
LtoM
N
N
C
N
N
LtoM
N
N
L
L
L
L
N
N = No birds observed
L = Low density
M = Moderate density
H = High density
* = No data collected
AK0043.W51
3-174
-------
Marine Bird Density Per Kilometer1
No Survey
ourvey/iNO oirus :
50-100
•i rvjcn ^^1 — 1 nn
: I LrOU ^^H > I UU
38°N
37°30'N
Transverse Mercator Projection
Scale
0 5 10 15 20
-123°30'w
-123°w
Figure 3.3.4-1.
Density Estimates for all Marine Bird Species During June 1986,
a Poor Rockfish Year.
Source: Ainley and Allen (1992)
AK0100
3-175
-------
Marine Bird Density Per Kilometer1
No Survey
Survey/No Birds
0.01-10
50-100
>100
38°N
37°30'N
Transverse Mercator Projection
Scale
0 5 10 15 20
-123°w
-122°30-w
Figure 3.3.4-2.
Density Estimates for all Marine Bird Species During June 1987,
a Good Rockfish Year.
Source: Ainley and Allen 1992.
AK0101
3-176
-------
Marine Bird Density Per Kilometer2
No Survey
ourvcy/iNO Diius ttt
001-10 50-100
1A.KA ^^1 -^ 1ATI
era IU-OU ^^H > 1UU 1
38°N
37°30'N -
Transverse Mercator Projection
Scale
0 5 10 15 20
-123030^w
-123°w
-122°30Vv
Figure 3.3.4-3.
Density Estimates for all Marine Bird Species During June 1991,
an Intermediate Rockfish Year.
Source: Ainley and Allen 1992.
AK0102
3-177
-------
Boekelheide (1990) concluded that the feeding range of pigeon guillemots, Cassin's and
rhinocerus auklets, tufted puffins, sooty shearwaters, and many other resident species primarily
is a response to food availability as opposed to nesting activities. Further, at least in the
summertime, the natural history of breeding marine birds of the Gulf of the Farallones, including
visitors such as the sooty shearwater, is based on a "juvenile rockfish economy." When juvenile
rockfish are available, foraging habits, behaviors, and diets of many species overlap extensively.
The dominant juvenile rockfishes used as prey are yellowtail rockfish (Sebastes flavidus) and
shortbelly rockfish (5. jordani). When rockfish are unavailable or in lower abundance (e.g.,
during warm-water years), they are replaced in the diet of many species by anchovies and a
variety of other prey including cephalopods and zooplankton. Additional prey species include
hake, smelt, and squid, all of which are considered either midwater-schooling species or species
that avoid the surface. The distribution, abundance, and size classes of many fish species,
including shortbelly rockfish, within the LTMS study areas are presented in Section 3.3.3.
Figure 3.3.4-1 indicates that during a poor rockfish year (e.g., 1986) marine bird densities are
spread relatively evenly throughout the Gulf of the Farallones. During a good rockfish year (e.g.,
1987) densities are concentrated around breeding sites, such as the Farallon Islands (Figure
3.3.4-2). Marine bird densities for an intermediate rockfish year (1991) are more scattered over
the region, with highest densities occurring within the GOFNMS (Figure 3.3.4-3).
Estimated densities of the ten marine bird species were relatively greatest in LTMS Study Areas
2 and 5 (Ainley and Boekelheide 1990; Ainley and Allen 1992; Jones and Szczepaniak 1992).
Tufted puffins were observed too rarely to derive density estimates for the three representative
years; the only sighting of this species within a study area during the 1985-1991 surveys was
recorded in 1985 within Study Area 2. The following sections provide detailed discussion of
distributions, densities, and ecology of the ten representative species.
3-178
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3.3.4.1 Distribution, Abundance, and Ecology of Representative Breeding Species
Ashy Storm-Petrel
Ashy storm-petrels are year-round residents that breed in the Gulf of the Farallones
(Table 3.3.4-1). Eighty-five percent of the world population of ashy-storm petrels breed and
reside there (Ainley and Allen 1992). They typically feed over pelagic waters at least 25 km
from the Farallon Islands, but they also may feed over waters near the shelf break (~ 200 m)
where upwelling events are more frequent (Ainley and Boekelheide 1990). However, they often
occur over mid-slope waters (Jones and Szczepaniak 1992), and are presumed to eat fish and
crustaceans (Center for Marine Studies 1985). A comparison of density estimates for this species
within the Gulf of the Farallones indicates that of the four LTMS study areas, Study Areas 3 and
5 contain greatest abundances of ashy storm-petrels (Table 3.3.4-2).
Brandt's Cormorant
The Brandt's cormorant population in the Gulf of the Farallones represents approximately ten
percent of the world population of this species (Ainley and Allen 1992). This species also is a
breeding resident of the Gulf of the Farallones. Brandt's cormorants feed in San Francisco Bay
in early spring, up to 80 km from nesting sites on the Farallon Islands. However, they may shift
later in the season to feed near the Islands or in coastal waters (Ainley and Boekelheide 1990).
Estimated densities of this species within the LTMS study areas are low (Table 3.3.4-2), probably
due to their preferred feeding habitat in shallow waters over flat sand or mud. Populations of
greater than 100 individuals/km2 can be found in the immediate vicinity of the Farallon Islands
(Ainley and Allen 1992). Brandt's cormorants often occur over shelf and upper slope waters
where water depths range from a few hundred to 1,000 m (Jones and Szczepaniak 1992).
Nearshore feeding areas range from 10-60 m in depth over flat sand or mud substrate to offshore
rocky bottom sites up to 120 m. Their prey items include demersal fish species such as rockfish
(Sebastes flavidus and S. jordani), flatfishes, tomcod (Microgradus proximus), midshipman
(Porichthys notatus), and cusk eels (Chilara taylori) (Ainley and Boekelheide 1990).
3-179
-------
Western Gull
Western gull populations are widespread throughout the study region and utilize the Gulf of the
Farallones as an important breeding area (Ainley and Boekelheide 1990). Approximately 50
percent of the world population of this species nests in the Gulf of the Farallones (Ainley and
Boekelheide 1990). Historic studies reported low densities in the vicinity of Study Areas 2, 3,
and 5; no observations were made in Study Area 4 (Ainley and Boekelheide 1990). Recent
censuses of all of the study areas recorded the highest densities in Study Areas 2 and 5 (Ainley
and Allen 1992; Jones and Szczepaniak 1992). This probably is due to the relative proximity of
these two study areas to nesting sites on the Farallon Islands in comparison to Study Areas 3 and
4. Jones and Szczepaniak (1992) observed the highest species densities near Southeast Farallon
Island; low to moderate densities were observed in or near Study Areas 2, 3, 4, and 5. Western
gulls have a wide diet which includes fish, predominantly juvenile rockfish (Ainley et al. 1987),
but they also consume marine invertebrates; to a lesser extent, marine bird eggs and young, seal
placenta, and other organic materials are scavenged by the gull.
Common Murre
The common murre, a resident breeding species, occurs primarily over the continental shelf
(Jones and Szczepaniak 1992; Ainley and Allen 1992). Breeding populations show considerable
fluctuations, ranging from approximately 400,000 individuals in 1850 to a few hundred
individuals in the early 1900s. The 1986 breeding population consisted of approximately 39,000
birds (Ainley and Boekelheide 1990). Observations of this species during the breeding seasons
of 1986, 1987, and 1991, consistently indicated low densities (0.01-10 individuals/km2) within
Study Area 2 (Ainley and Allen 1992). Common murres also were observed at low densities
(0.01-10 individuals/km2) within Study Area 3 in 1986 (a poor rockfish year) and at moderate
densities (10-50 individuals/km2) during the same year within Study Area 5. This species was
not observed within Study Area 4 during the three survey years. Similar densities (low to
moderate in the region of Study Areas 2 and 3 and moderate to high in Study Area 5) were
observed by Ainley and Boekelheide (1990). Seasonal surveys (Jones and Szczepaniak 1992)
3-180
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indicated that low densities of this species were observed over Study Area 2; no common murres
were observed in any of the other LTMS study areas. Common murres exhibit great variation
in feeding habitats. In early spring, they occur over the outer continental shelf. In the spring
and summer of cool-water (i.e., good rockfish years), their feeding range is somewhat constricted
to shallower water closer to the Farallon Islands. At that time, murres feed heavily on rockfish,
northern anchovy (Engraulis mordax), market squid (Loligo opalescens), and euphausiids. In
warmer years, they occur farther from the Farallon Islands, especially over the shelf towards the
mainland, where they feed heavily on anchovies, and secondarily over slope waters (e.g., Study
Area 5). By July, they begin to move toward the coast. However, when juvenile rockfish are
abundant, they remain offshore longer (Ainley and Boekelheide 1990).
Pigeon Guillemot
The pigeon guillemot is a common (estimated population of 1,000 to 25,000 individuals)
summer-breeding species within the Gulf of the Farallones (Ainley and Allen 1992). The
majority of the resident population appears to occur around the Farallon Islands and in areas to
the north. This species forages in relatively shallow waters over rocky substrate, and rarely feeds
in waters farther than 15 km from the Farallon Islands (Ainley and Boekelheide 1990). Recent
surveys conducted by the PRBO during the spring of 1986, 1987, and 1991 indicated that no
pigeon guillemots were observed within Study Areas 2, 4, or 5; however, low densities occurred
in Study Area 3 in June 1991 (Ainley and Allen 1992). EPA surveys (1992) recorded sightings
in February, May, and August of 1991, although no sightings were made within any of the LTMS
study areas and actual counts or densities were not reported.
Sooty Shearwater
Sooty shearwaters typically are non-breeding, summer visitors to the study region, and occur
throughout the shelf and slope waters of the Gulf of the Farallones (Table 3.3.4-1). An estimated
one million sooty shearwaters are present between May and August of cool-water (high
productivity) years (KLI 1991). Of the four LTMS study areas, Study Area 2 supported the
3-181
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highest densities of sooty shearwaters, especially during 1987, a good rockfish year (Ainley and
Allen 1992). However, in May 1991, high densities of sooty shearwaters were reported in the
vicinity of Pioneer Canyon (between Study Areas 3 and 4) (Jones and Szczepaniak 1992).
Surveys conducted by Ainley and Boekelheide (1990) recorded low to high densities of sooty
shearwaters in Study Areas 2 and 3, and moderate to high densities in the region of Study Area
5. Sooty shearwaters are pursuit divers, preying on anchovies, market squid, euphausiids, and
juvenile rockfish.
Cassin's Auklet
Cassin's auklets are year-round, breeding residents of the Gulf of the Farallones, typically
foraging over slope waters (Table 3.3.4-1). They are the most abundant marine bird on the
Farallon Islands (Sowls et al. 1980), and are distributed widely throughout the study region.
Cassin's auklets occurred at low densities (0.01-10 individuals/km2) in Study Area 3 and
moderate densities (10-50 individuals/km2) in Study Areas 2 and 5 (Ainley and Allen 1992). No
birds were observed in Study Area 4 during the three survey years, except in 1991, when low
densities (0.01-10 individuals/km2) were recorded (Ainley and Allen 1992). Surveys conducted
by EPA (1992) indicated an absence or low densities of 0.01-10 individuals/km2 within all study
areas. Ainley and Boekelheide (1990) reported that Cassin's auklets occurred in low densities
near Study Area 2, and from low to high densities in the region of Study Areas 3 and 5. No
surveys were conducted in Study Area 4. Cassin's auklets can dive to depths of 35 m for their
prey. Ninety percent of their diet is composed of euphausiids (Thysanoessa sp. and Euphausia
sp.) and larval fish.
Rhinoceros Auklet
Rhinoceros auklets also are year-round, breeding residents of the Gulf of the Farallones and are
found over shelf, slope, and pelagic waters. The highest overall species densities (10-50
individuals/km2) occurred within Study Area 2 (Ainley and Allen 1992; Jones and Szczepaniak
1992) although similar densities were recorded for Study Area 5 during 1987 (Ainley and Allen
3-182
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1992). Rhinoceros auklets occurred at relatively low densities over Study Areas 3 and 4. Ainley
and Boekelheide (1990) reported similar results, except for Study Area 3: rhinoceros auklets
were observed in relatively high densities in Study Areas 2 and 3, and low to moderate densities
in Study Area 5. Rhinoceros auklets are pursuit divers (KLI 1991) that feed primarily on fish
(Briggs et al. 1987).
Pink-footed Shearwater
Pink-footed shearwaters are non-breeding, summer visitors to the region, occurring over shelf and
slope waters (Table 3.3.4-1). Point Reyes Bird Observatory surveys indicated a relatively low
occurrence of this species in all of the study areas, except for Study Area 2 where high densities
of over 100 individuals/km2 were recorded in 1987 (Ainley and Allen 1992). Similarly, EPA
surveys conducted during August 1990 recorded low densities (0.01-10 individuals/km2) within
LTMS Study Areas 4 and 5. However, no sightings of pink-footed shearwaters were made within
Study Area 2 and moderate densities (10-50 individuals/km2) were observed over Study Area 3
(Jones and Szczepaniak 1992).
Tufted Puffin
Tufted puffins are breeding residents of the Gulf of the Farallones; less than 50 breeding pairs
occur on the Farallones (Table 3.3.4-1). Breeding season censuses conducted from 1985 through
1991 indicated that tufted puffins rarely occurred within any of the study areas (Ainley and Allen
1992). Only a single individual was recorded within Study Area 2 (Figure 3.3.4-4); no tufted
puffins were observed within any of the other study areas during the seven survey years. These
surveys also indicated that the majority of tufted puffins occurred to the north and west of the
Farallon Islands, close to the eastern boundary of Study Area 5 (Figure 3.3.4-4). Although Jones
and Szczepaniak (1992) recorded sightings of tufted puffins during four of five surveys, counts
were determined to be too low for inclusion in species density estimates. Ainley and
Boekelheide (1990) recorded low densities of tufted puffins in Study Area 5. Tufted puffins
3-183
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Marine Bird Counts
O
2-10
Breeding Site
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
of The Farallones
M
Alternative
SiteS
Alternative
Gumdr<Łp $ Site 3 \
Se
Pioneer
Searuount
»Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
-123°30lw
-123°w
-122030Vv
Figure 3.3.4-4. Tufted Puffin Counts in the Gulf of the Farallones Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0103
3-184
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forage in deeper waters of the continental shelf (Ainley and Boekelheide 1990). Juvenile
blackcod are an important prey item (Ainley and Allen 1992).
Brown Pelican
In addition to the ten representative breeding species considered, one migratory species, the
brown pelican (Pelecanus occidentalis), occurs in significant numbers within the region and is
listed by both State and Federal agencies as endangered. The nesting range for brown pelicans
extends from the Santa Barbara Channel to Mexico. Two major roosting sites are Ano Nuevo
Island and Southeast Farallon Island (Briggs et al. 1983). Daytime surveys of these areas
recorded 500 animals, whereas nocturnal censuses recorded several thousand individuals (Briggs
et al. 1983). Surveys conducted from 1985-1991 indicated that California brown pelican
populations were centered along the coastline and over shelf waters including Study Area 2
(Figure 3.3.4-5) (Ainley and Allen 1992). EPA surveys (1992) also recorded the highest numbers
of brown pelicans over the continental shelf, particularly near the periphery of Study Area 2.
Brown pelicans typically forage in shallow waters, and feed primarily on the northern anchovy
(Engraulis tnordax) (Anderson et al. 1980; Anderson et al. 1982), but they can be found during
calm weather in waters over the continental slope (Briggs et al. 1983; Jones and Szczepaniak
1992).
3.3.4.2 Summary of Study Area Usage by Marine Bird Species
In general, assessments of densities of the ten representative species indicate that of the four
areas, Study Areas 2 and 5 support the largest number of marine birds (Table 3.3.4-2). Study
Area 2 is the only site located over shelf waters; these waters represent a more productive area
for foraging marine birds (Ainley and Allen 1992; Jones and Szczepaniak 1992). Of the
remaining three study areas, Study Area 5 is located closest to nesting sites of breeding species
on the Farallon Islands, and thus is likely to be a more convenient feeding ground for breeding
individuals. Ainley and Allen (1992) suggested that due to limited prey availability and
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Marine Bird Counts
O i
0 2-10 n 11-100 ^ Breeding Site
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary I
I
Cordell Bank /
50m /
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marin^Sanctuary
200 m
500 m\\ Farallon
San
Francisco
Bay
Alternative
SiteS
Alternative
Gumdr«6p Q Site 3 \
Seamount
Pioneer
Seamount
I Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
O
-123030-w
-123°w
-122°30'w
Figure 3.3.4-5. California Brown Pelican Counts in the Gulf of the Farallones Region,
1985-1991.
Source: Ainley and Allen 1992.
AK0104
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prevailing northerly winds, marine birds forage less often to the south than to the north, west,
or east of the Farallon Islands. An upwind return flight for an adult bird with prey is estimated
to be relatively more difficult energetically. Thus, during the May/June breeding season, regions
south of the Farallon Islands (such as Study Areas 3 and 4) may be less preferred as feeding
grounds due to relatively lower prey availability (as compared to shelf waters) and the higher
energy expenditure required to return to upwind nesting sites rather than downwind sites (e.g.,
Study Area 5) (Ainley and Allen 1992). Density estimates of all marine birds during poor, good
and intermediate rockfish years (Figures 3.3.4-1 through 3.3.4-3, respectively) also indicate that
the greatest abundances of marine birds are found within Study Areas 2 and 5 (Ainley and Allen
1992).
Based on known habitats from the literature, the total number of bird species potentially utilizing
the different study areas decreases as the distance from shore increases (Briggs et al. 1987). This
trend is consistent for breeding species, seasonal visitors, and passage migrants and tends to
indicate that offshore areas such as LTMS Study Area 5 should have low utilization as bird
habitats. Although Study Area 5 is far from shore, it lies in close proximity to a land source:
the Farallon Islands. The relatively close distance between Study Area 5 and the Farallon Islands
may explain the higher use of this area by marine birds. Thus, based on actual surveys (Ainley
and Boekelheide 1990, Ainley and Allen 1992, Jones and Szczepaniak 1992), LTMS Study Areas
2, 3, and 5 show the highest utilization by species which breed in the Gulf of the Farallones, are
common residents, are geographically limited, and/or have legal status.
3.3.5 Marine Mammals
This section presents information on marine mammals of the study region including cetaceans
(Section 3.3.5.1), pinnipeds (Section 3.3.5.2), and fissipeds (Section 3.3.5.3).
Twenty-one species of cetaceans (dolphins, porpoises, and whales), six species of pinnipeds (sea
lions and seals),, and one species of fissiped (sea otter) comprise the marine mammal fauna of
central California (KLI1991). Twenty-six of these species (twenty cetaceans, five pinnipeds, and
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the fissiped) are frequently observed in the Gulf of the Farallones region (Table 3.3.5-1). All
marine mammals are protected by the Marine Mammal Protection Act (MMPA 1972, amended
1988), administered by the National Oceanic and Atmospheric Administration/National Marine
Fisheries Service (NOAA/NMFS) and the United States Fish and Wildlife Service (USFWS).
In addition, gray, humpback, blue, finback, sei, right, and sperm whales are Federally listed as
endangered species and thereby protected by the Endangered Species Act (ESA 1973, amended
1978). Recently, NOAA/NMFS has recommended that the eastern Pacific stock of gray whales
be removed from the endangered species list because current estimates suggest the population has
recovered from commercial whaling (IWC 1990). Formal action on the recommendation to de-
list gray whales is expected by 1993 (MMS 1991). The northern fur seal, northern sea lion, and
the sea otter are designated as threatened species under Federal law and fully protected under
California law. Because marine mammals are protected, evaluation of the study areas for this
EIS includes consideration of the extent to which the areas are used by marine mammals for
breeding, weaning, feeding, or migration. Seasonal patterns of distribution in the LTMS study
areas may suggest alternative disposal strategies that would minimize impacts to these species.
Broad-scale surveys of marine mammals off central and northern California, including the Gulf
of the Farallones and the Farallon Islands, were conducted by Dohl et al. (1983) and Bonnell et
al. (1983). Dohl et al. focused on the seasonal occurrence of cetaceans while Bonnell et al.
studied pinnipeds and sea otters during a three-year (1980-1983) research program. Both of
these historic studies provide seasonal estimates of the relative abundance of marine mammals
for waters encompassing each of the study areas. In addition, a three-year (1986-88) photo-
identification study on humpback and blue whales within and near the Gulf of the Farallones
provides information on movements and site fidelity for these two endangered whale species
common to the region (Calambokidis et al. 1990a, 1990b). More recent marine mammal surveys
have focused on the LTMS study region (Ainley and Allen 1992; Jones and Szczepaniak 1992).
The PRBO surveys (Ainley and Allen 1992) provide information on study area use by marine
mammals; this information was collected during seven cruises conducted each June from
1985-91. Thus, seasonal events within the study region, such as the spring and fall migrations
of gray whales and the late summer concentrations of humpback whales, are not represented in
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Table 3.3.5-1.
Marine Mammals Observed in the Vicinity of the Gulf of the Farallones.
Those species having legal status (special concern*, threatened", or endangered*") are shown in bold. Species are listed according to their
occurrence within the study region, such as breeding (breed in area), seasonal visitor (seasonal residents, feed in area), migrant (migrate through area
but may feed as moving through area), or incidental. Relative occurrences refer to the following: Abundant = over 5,000 individuals, Common =
between 1,000-5,000 individuals, Uncommon = between 100-1,000 individuals, and Rare = less than 100 individuals. Habitat areas refer to occurrences
over the following water depths: shelf = < 200 m, slope = 200-1999 m, pelagic = > 1999 m. Species are listed according to their activity within the
study region, such as breeding, seasonal visitor, or migrant.
Primary source: Ainley and Allen (1992)
Scientific
• Name
Common I
Name ;
Activity Within
Study Region
Seasonal
' Status
' ReMve
Occurrence
Prectorninaftt Habitat
Cetaceans
(Approx 4 spp.)
Balaenoptera musculus'"
Delphinus delphinus
Phocoenoides dalli
B. physalus"'
Eschrichtius robustus***
Phocoena phocoena
Megaptera novaeangliae"*
Orcinus orca
B. acutorostrata
Beaked Whale
Blue Whale
Common Dolphin
Dall's Porpoise
Finback Whale
Gray Whale
Harbor Porpoise
Humpback Whale
Killer Whale
Minke Whale
?
Seasonal Visitor
Seasonal Visitor
Breeding
Migrant
Seasonal Visitor/
Migrant
Breeding
Seasonal Visitor
?
Seasonal Visitor
Year-round
Summer
Summer
Year-round
Summer
Year-round
Year-round
Summer
Year-round
Summer
Rare
Uncommon
Rare
Abundant
Rare
Common
Common
Common
Uncommon
Common
Pelagic
Shelf, slope
Shelf
Shelf, slope
Shelf, slope, pelagic
Shelf, slope
Shelf
Shelf, slope
Shelf, slope
Shelf, slope
oo
AK0044.W5!
-------
Table 3.3.5-1.
Continued.
ScSentlc • |
Name :
Lissodelphis borealis
Lagenorhyncus obliquidens
Globicephala spp.
Eubalaena gracialis"*
Grampus griseus
ft borealis"'
Physeter macrocephalus***
Gomm
Name ;
Northern Right Whale Dolphin
Pacific White-sided Dolphin
Pilot Whale
Right Whale
Risso's Dolpin
Sei Whale
Sperm Whale
Asfivity Within
Study ftegion
Breeding
Breeding
Migrant
Incidental
Seasonal Visitor
Incidental
Incidental
Seasonal :
States : ' • i
Year-round
Year-round
Winter
?
Year-round
Summer
Year-round
Relative '
Occurrence
Common
Abundant
Uncommon
Rare
Abundant
Rare
Common
Predominant Habitat
Shelf, slope
Slope, pelagic
Slope, pelagic
?
Shelf, slope
Pelagic
Slope, pelagic
Pinnipeds
Zalophus califomianus
Phoca vitulina
Mirounga angustirostis
Callorhinus ursinus"
Eumetopias jubatus"
California Sea Lion
Harbor Seal
Northern Elephant Seal
Northern Fur Seal
Northern Sea Lion
Seasonal Visitor
Breeding
Breeding/Seasonal
Visitor
Seasonal Visitor
Breeding
Year-round
Year-round
Year-round
Year-round
Year-round
Abundant
Common
Common
Abundant
Uncommon
Shelf
Shelf
Shelf, slope, pelagic
Slope, pelagic
Shelf
Fissipeds
Enhydra lutris" | Sea Otter
Seasonal Visitor
Year-round
Common
Shelf
u>
I—*
VC
o
AK0044.W51
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these survey results. In contrast, EPA (Jones and Szczepaniak 1992) conducted five cruises
between August 1990 and November 1991 on marine mammal use of the region. Although
coverage of the four study areas was not uniform, these surveys supply incidental information
on seasonal occurrence. Therefore, site-specific data (historic and recent) exist for marine
mammals of the region and may be used to determine relative marine mammal use of the four
study areas.
3.3.5.1 Cetaceans
In general, cetaceans are most common in continental slope (slope) waters (e.g., over water
depths of 200-2,000 m). Dohl et al. (1983) recorded five times as many sightings in slope
waters as in continental shelf (shelf) waters (less than 200 m), and three times the numbers
sighted in deep waters (greater than 2,000 m).
During the 1980-83 surveys, Dohl et al. (1983) counted 116,800 cetaceans comprising 18
species. The most abundant odontocetes (i.e., toothed cetaceans) were the Pacific white-sided
dolphin, followed by the northern right whale dolphin, Risso's dolphin, Dall's porpoise, and the
harbor porpoise. The most common baleen whales were the California gray whale followed by
the humpback whale. Sperm, blue, minke, and killer whales also were sighted, although their
abundances were lower. Overall, the highest densities of cetaceans occurred in autumn and
winter.
Results from Dohl et al. (1983) indicate that for all cetaceans combined, abundance estimates
were highest near the Gulf of the Farallones. According to this study, all slope and deep-water
study areas contained cetaceans during March through May with moderate to high densities
(0.301-1.2/km2) in Study Area 5, moderate densities (0.301-0.60/km2) in Study Area 3, and low
densities (0.01-0.15/km2) in Study Areas 2 and 4.
Recent censuses indicated similar marine mammal occurrences and species within the Gulf of the
Farallones region (Ainley and Allen 1992; Jones and Szczepaniak 1992). Similar to results from
3-191
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Dohl etal. (1983), during the June 1985-91 surveys (Ainley and Allen 1992), a higher incidence
of cetaceans was reported in slope and deep waters. Of the four study areas, the deep waters
of Study Area 5 had the highest counts for a single species (22 Pacific white-sided dolphins)
(Ainley and Allen 1992). However, the highest number of cetacean species and the highest
counts for some species, including 15 Pacific white-sided dolphins, 7 humpback whales, 2 Risso's
dolphins, and 1 minke whale, were reported for the slope waters of Study Area 4. Cetaceans
observed within Study Area 3 included 12 Risso's dolphins, 3 Pacific white-sided dolphins, and
1 Dall's porpoise. In contrast, only three cetaceans (2 harbor porpoises and 1 humpback whale)
were observed in shelf waters within Study Area 2.
In surveys during June 1985-91, Dall's porpoise, Pacific white-sided dolphin, and harbor
porpoise were the most abundant odontocetes within the study region (Ainley and Allen 1992).
Of the larger cetaceans, humpback whales were the most abundant, followed by minke and gray
whales. Seasonal surveys conducted by the EPA (Jones and Szczepaniak 1992) also reported
Dall's porpoise and Pacific white-sided dolphins as the most frequently observed cetaceans,
although only two harbor porpoises were observed during the entire study. In contrast to the
findings of Dohl et al. (1983), no gray whales were observed during EPA surveys; instead,
humpback whales were the most frequently sighted baleen whales (Jones and Szczepaniak 1992).
Ainley and Allen (1992) suggest that Study Area 5 may have the relatively greatest importance
to marine mammals based on the number of individuals observed there. However, seasonal
surveys suggested that marine mammal abundances within Study Area 3 were greater than
expected (Jones and Szczepaniak 1992). Also, during these surveys, numbers observed within
Study Area 5 were less than expected and no marine mammals were observed within Study
Area 4.
The seven species of large whales that occur within the study region are classified as seasonal
visitors or migrants (Table 3.3.5-1). Gray, humpback, and blue whales are listed as seasonal
visitors because they likely feed opportunistically in, as well as migrate through, the Gulf of the
Farallones region. Conversely, finback, sperm, sei, and right whales are listed as migrants or
3-192
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incidentals because they appear to pass through the area during seasonal migrations, rarely
stopping to feed. Periods of likely occurrence in the Gulf of the Farallones region for the seven
species are shown in Figure 3.3.5-1. The occurrence of these seven species within the study
areas warrants special attention because all are Federally listed as endangered (see Section 3.3.6,
Endangered Species).
Pacific White-Sided Dolphins
Pacific white-sided dolphins were the most abundant cetacean observed off the central California
coast, comprising 40% of all animals sighted (Dohl et al. 1983). These dolphins generally occur
in waters over and seaward of the continental slope, except during spring when they occur in
continental shelf waters from Half Moon Bay to Monterey Bay (Dohl et al. 1983). They feed
on northern anchovy, whiting, saury, and squid at depths in excess of 120 m (Dohl et al. 1983).
Juvenile animals were observed from July through October with the highest number of sightings
between Point Conception and Point Reyes and with heavy use of the Gulf of the Farallones
region (Dohl et al. 1983). Counts of this species over five years indicated moderate numbers
(11-100 individuals) observed within Study Area 4 and in close proximity to Study Areas 3 and
5 (Figure 3.3.5-2) (Ainley and Allen 1992). During the EPA surveys, this species was seen in
low to moderate abundances Study Area 3 and low abundances in Study Area 5 during August
1990 and 1991 (Jones and Szczepaniak 1992). These results verify that slope and deep-water
habitats are used more often than shelf waters, as reported by Dohl et al. (1983).
Northern Right Whale Dolphin
Northern right whale dolphins comprised 35% of all animals sighted by Dohl et al. (1983), and
usually were observed over deep waters. They feed primarily on squid, lanternfish, and other
mesopelagic fishes at depths greater than 250 m (Leatherwood and Reeves 1982; Dohl et al.
1983). Sixty-two percent of all juveniles were sighted between Point Piedras Blancas and Point
Pinos, south of the Gulf of the Farallones (Dohl et al. 1983). There was a tendency for northern
3-193
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Species
Name
Months of the Year
FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC JAN FEB
Gray
Whale
Humpback
Whale
Y//7/
Blue
Whale
Finback
Whale
Right
Whale
Sei
Whale
Sperm
Whale
Northern migration
Y////A Seasonally resident
in region
Southern migration
Figure 3.3.5-1. Whale Migrations (Northern and Southern) and Times During Which
Each Species May Occur in the Study Region.
Modified from Dohl et al., 1983.
AK0105
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Marine Mammal Counts
O 1
O 2-10
11-100
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marine Sanctuary
200m
Farallon
. Islands
Alternative ,.
Site5' tt
Gumdr
SeamoUnt
I Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
-123°30'w
-123°w
-122°30'w
Figure 3.3.5-2. Pacific White-Sided Dolphin Counts in the Gulf of the Farallones
Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0106
3-195
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right whale dolphins to be found over deeper waters in autumn (1,440 m) than in spring (862 m),
although this pattern was not consistent from year to year (Dohl et al. 1983). Overall, the
species' distribution appears to shift south and inshore from October through June, then north and
offshore from July through September (Leatherwood and Reeves 1982). During the PRBO
(1992) surveys, most northern right whale dolphins were seen near the eastern boundary of Study
Area 5, with fewer sighted near Study Area 3 (Figure 3.3.5-3). EPA sightings of this species
were over slope waters between Study Areas 3 and 4 (Jones and Szczepaniak 1992). All EPA
sightings occurred during August and October surveys, confirming the suggestion by Dohl et al.
(1983) that northern right whale dolphins tend to be found over slope waters during autumn.
Thus, like Pacific white-sided dolphins, with which they commonly co-occur, northern right
whale dolphins prefer slope and deep-water habitats over continental shelf waters.
Risso's Dolphin
Risso's dolphins comprised 18% of the cetaceans sighted by Dohl et al. (1983). This species
often is found offshore in deep temperate and tropical waters where it feeds primarily on squid
(Leatherwood and Reeves 1982). The few Risso's dolphin that were seen within the study region
during the PRBO surveys were near or within Study Areas 3 and 4 (Ainley and Allen, 1992)
(Figure 3.3.5-4). Although Risso's dolphins occur regularly in the Gulf of the Farallones, the
population reportedly is concentrated in southern California waters (Dohl et al. 1983). Jones and
Szczepaniak (1992) recorded a single sighting of Risso's dolphins within Study Area 4.
Dall's Porpoise
Dall's porpoise numerically represented only 2% of the cetaceans seen, but were the most
frequently encountered species during the 1980-83 surveys (Dohl et al. 1983). Abundance
indices were highest from mid-summer through autumn, and lowest in winter.
3-196
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Marine Mammal Counts
O 1
O 2-10
11-100
38°N -
37°30'N -
CordellBank /
National Marine /
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marine Sanctuary
200m
500 m \\^ Farallon
. Islands
,,, San ,
Francisco^
Gumdrip
Seamount
\ Pioneer
iCanyon
Alternativ
jS!ta<
Guid
Monterey Bay
National Marine
Sanctuary
-123°30'w
-123°w
-122°30-w
Figure 3.3.5-3. Northern Right Whale Dolphin Counts in the Gulf of the Farallones
Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0107
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Marine Mammal Counts
O 1
O 2-10
11-100
38°N -
37°30'N -
Cordell Bank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Seals
0 5 10 15 20
Cordell Bank
50m
Gulf of The Fa/aTltnes
National Marine/dflnctuary
s±7
Farallon
. Islands
San
Francisco
Bay
Alternative
SiteS
• Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
Quid
Seambunt
-123°30'w
-123°W
-122°30'w
Figure 3.3.5-4. Risso's Dolphin Counts in the Gulf of the Farallones
Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0108
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Similarly, Dall's porpoises were the cetaceans observed most often within the study region during
the PRBO (1992) surveys, although sightings within specific study areas were rare
(Figure 3.3.5-5). During the EPA (1992) surveys, this species occurred in the study region region
most often in summer, especially within Study Area 3 (Jones and Szczepaniak 1992). The
greatest numbers occurred along the seaward edge of the continental shelf and slope waters
(Ainley and Allen 1992; Jones and Szczepaniak 1992). Dall's porpoises are nocturnal feeders,
primarily consuming anchovies, squid, crustaceans, and deep-water fishes (Morejohn 1979; Jones
1981; Ainley and Allen 1992). Preferred prey abundance may significantly affect the species
foraging range. For example, the highest densities of Dall's porpoises were observed around the
Farallon Islands coincident with unusually high numbers of anchovies (Ainley and Allen 1992).
Harbor Porpoise
Harbor porpoise are the most common nearshore cetaceans in the central California region
(Leatherwood et al. 1982; Dohl et al. 1983). Seasonal movements seem to be inshore-offshore
rather than north-south and may be determined by prey availability. Harbor porpoise feed on
juvenile rockfish, herring, mackerel, sardines, pollack, and whiting (Leatherwood and Reeves
1982). Dohl et al. (1983) estimated a peak central California population of 3,000 porpoises in
the fall season, although recent observations suggest the species is present year-round in the Gulf
of the Farallones (Szczepaniak and Webber 1985). Harbor porpoise rarely are seen in waters
deeper than 180 m, and usually occur within the 18 m isobath (Caldwell and Caldwell 1983).
Sightings during the PRBO and EPA (1992) surveys support this observation. All animals were
seen in continental shelf waters with only one animal in Study Area 2 (Ainley and Allen 1992)
(Figure 3.3.5-6).
Gray Whales
The eastern Pacific population of gray whales is currently estimated at 21,113 individuals and
is considered to be essentially recovered from historical reductions attributable to commercial
whaling (IWC 1990). Migrations occur twice annually between winter breeding lagoons in Baja
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Marine Mammal Counts
O 1
O 2-10
11-100
38°N -
37°30'N -
Cordell Bank /
National Marine /
Sanctuary
Transverse Mercator Projection
Scale
0 B 10 15 20
I Pioneer
iCanyon
rey Bay
National Marine
Sanctuary
-123°30'w
-123°w
-122°30'w
Figure 3.3.5-5. Call's Porpoise Counts in the Gulf of the Farallones
Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0109
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Marine Mammal Counts
O 1
O 2-10
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary I
I
Cordell Bank /
50m /
Transverse Mercator Projection
Scale
0 5 10 15 20
GuntorThe Farallones
National Marine Sanctuary
200m
500 m\\^ Farallon
. Islands
0TQOO
Alternative
Sites
\Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
Guid
Seambunt
-123°30'w
-123°W
-122°30'w
Figure 3.3.5-6. Harbor Porpoise Counts in the Gulf of the Farallones
Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0110
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California and summer feeding grounds in the Bering and Chukchi seas (Clarke et al. 1989;
Moore et al. 1986; Swartz 1986). There is recent evidence of year-round residency of some gray
whales in the Gulf of the Farallones (PRBO, unpubl. data).
Southbound whales may appear as early as October, with the majority of animals occurring in
late December-early January (Dohl et al. 1983). Individuals generally tend to avoid turbid
waters, such as those receiving run-off following extensive rainfall, and usually pass west of the
Farallon Islands on their way south from Point Reyes (Dohl et al. 1983). Newborn whales have
been observed in northern, central, and southern California waters (Jones and Swartz 1990),
suggesting that whales do not calve solely in the lagoons of Baja California. In addition, the
year-round residency of some gray whales in the Gulf of the Farallones indicates that some
breeding/calving of gray whales may occur in the study region.
The northward migration period is less well defined, but generally occurs from mid-January
through June (Dohl et al. 1983; Herzing and Mate 1984). Northbound animals tend to stay closer
to shore. Poole (1984) described two migration corridors for northbound whales off San Simeon
(Piedras Blancas): a route 200 m to 3.2 km offshore used by whales not accompanied by calves,
and a route less than 200 m from shore used primarily by females with calves. The cow/calf
pairs closely followed the coastal contour, while whales using the "offshore" route often followed
a nearly straight line from one coastal promontory to the next. The route(s) used by northbound
whales in the Gulf of the Farallones region is unknown.
Few gray whale sightings were recorded during the PRBO surveys, although moderately high
counts were made near the northeast boundary of Study Area 5 (Figure 3.3.5-7) (Ainley and
Allen 1992). This overall scarcity of sightings could be due to limitation of the field effort
(May/June surveys only). However, no gray whales were observed during the EPA seasonal
surveys (Jones and Szczepaniak 1992). In recent years, 3 to 8 gray whales summered in the
vicinity of the Farallon Islands (Dohl et al. 1983; Huber et al. 1986). Gray whales feed on
infaunal crustaceans, primarily ampeliscid amphipods, and there are incidental reports of gray
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Marine Mammal Counts
CM
O 2-10
11-100
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
Cordell Bank
50m
Gulf of The Farallones
National Marine Sanctuary
200m
Farallon
• Islands
Alternative
SiteS
Alternative
Site3
\ Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
Quid
Seambunt
-123°30lw
-123°W
-122°30'W
Figure 3.3.5-7. Gray Whale Counts in the Gulf of the Farallones Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0111
3-203
-------
whales associated with sediment trails (which indicate feeding) near the Farallon Islands and off
Point Reyes (Nerini 1984; PRBO, unpubl. data). Gray whales summering off Vancouver Island
are principally engaged in feeding (Oliver et al. 1984), and there is some evidence that gray
whales feed opportunistically near the Farallon Islands as well (P. Jones, EPA, pers. comm.
1992).
Humpback Whales
The eastern north Pacific population of humpback whales migrates from summer feeding areas
in southern Alaskan waters to winter breeding areas in waters near Hawaii and Mexico (Johnson
and Wolman 1984; Baker et al. 1986). Humpbacks occur along northern and central California
from March through January, with the greatest numbers in waters near the Farallon Islands from
mid-August through October (Dohl et al. 1983; Calambokidis et al. 1990a). During summer
months, central California populations may reach 500 animals (Dohl et al. 1983). Annual local
populations have been estimated at roughly 150-200 whales in the region for the years 1986-88
(Calambodikis et al. 1990a). Humpbacks feed on baitfish, euphausiids, pelagic crabs, and a
variety of other prey in the Gulf of the Farallones in summer and early fall. Highest abundance
was observed in August between Study Areas 2 and 3 during EPA (1992) surveys
(Figure 3.3.5-8a), while data from the multi-year June surveys (Ainley and Allen 1992) suggested
higher relative abundance further south between Study Areas 3 and 4 (Figure 3.3.5-8b).
Calambokidis et al. (1990a) describe movement of humpbacks between feeding aggregations in
the Gulf of the Farallones and along the California coast, particularly Monterey Bay. Differences
in sighting distributions from the PRBO and EPA surveys could result from differences in survey
timing, or movement of the whales between Monterey Bay and Gulf of the Farallones feeding
areas.
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Marine Mammal Counts
O 1
O 2-10
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary '
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marine Sanctuary
200/77 c „
500 m\\^ Farallon
. Islands
San
Francisco
Bay
Alternative
SiteS
S*S*. I \J500m
Study
AreaS
I Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
-123°30lw
-123°w
-122°30'w
Figure 3.3.5-8a. Humpback Whale Counts in the Gulf of the Farallones Region, August
1990 and 1991.
Source: Jones and Szczepaniak 1992.
AK0112
3-205
-------
Marine Mammal Counts
O
2-10
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marine Sanctuary
200m
500 m \\_^ Farallon
. Islands
Alternative
SiteS
Monterey Bay
National Marine
Sanctuary
-123°30>w
-123°w
-122°30'w
Figure 3.3.5-8b. Humpback Whale Counts in the Gulf of the Farallones Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0113
3-206
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Blue Whales
Blue whales occur from the Chukchi Sea to waters off Costa Rica in the eastern north Pacific,
although specific migration patterns and feeding areas are poorly defined (Mizroch et al. 1984).
Like humpbacks, blue whales use the Farallon Basin for feeding in summer and early fall, but
occur in lower numbers (Dohl et al. 1983). A total of 179 blue whales were identified
photographically in the Gulf of the Farallones over three years (1986-88), with some movement
of individual whales between the Farallones and feeding aggregations in Monterey Bay
documented in 1987 and 1988 (Calambokidis et al. 1990b). In 1986, a single sighting of 41 blue
whales was recorded near Southeast Farallon Island (PRBO, unpubl. data), the same year that
unusually large aggregations of blue whales fed on euphausiids in Monterey Bay (Schoenherr
1991). During the EPA (1992) surveys, blue whales were seen in Study Area 3 and near Study
Area 2 in August, with most seen along the continental shelf break (Figure 3.3.5-9). No blue
whales were observed within survey transects during the June 1985-91 surveys (Ainley and Allen
1992).
Minke Whales
Minke whales are widely distributed in tropical, temperate, and polar waters (Leatherwood and
Reeves 1982). In the north Pacific, minkes winter from central California to near the equator,
with distribution shifting northward in summer from central California to waters off Alaska.
Minke whales appear to segregate by age/sex classes in all areas, which limits attempts to make
unbiased estimates of population size. There is evidence that minke whales are year-round
residents in Monterey Bay (Stern 1990) and the Gulf of the Farallones (PRBO, unpubl. data).
The sexes of resident populations in the Gulf and off Monterey migrate separately (Stern 1990).
Dohl et al. (1983) sighted 16 minke whales over 3 years, with only one animal seen near the
Farallon Islands in 1981. A single minke whale was observed within Study Area 4 during the
June PRBO (1992) surveys. The majority of minke whales observed during these surveys were
along the northern coastline of the study region (Ainley and Allen 1992) (Figure 3.3.5-10). EPA
3-207
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Marine Mammal Counts
O 1
O 2-10
38°N -
37°30'N -
CordellBank /
National Marine/
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
\\r>--'
I Pioneer
^Canyon
Monterey Bay
National Marine
Sanctuary
-123030-w
-123°w
-122°30'w
Figure 3.3.5-9. Blue Whale Counts in the Gulf of the Farallones Region, August
1990 and 1991.
Source: Jones and Szczepaniak 1992.
AK0114
3-208
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Marine Mammal Counts
O 1
Q 2-10
38°N -
37°30'N -
Cordell Bank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
Cordell Bank
50 m
Gulf of The Farallones
National Marine Sanctuary
200m
500 m \\^ Farallon
Islands
' O
Alternative
SiteS
\ Pioneer
\Canyon
Monterey Bay
National Marine
Sanctuary
-123°30'w
-123°w
-122°30'w
Figure 3.3.5-10. Minke Whale Counts in the Gulf of the Farallones
Region, 1985-1991.
Source: Ainley and Allen 1992.
AK011S
3-209
-------
surveys observed only two minke whales shoreward of the 100-ra isobath (Jones and Szczepaniak
1992).
Finback, Sperm, Sei, and Right Whales
Endangered finback, sperm, sei, and right whales rarely occur in the study region (Dohl et al.
1983), and none were observed during the PRBO (1992) and EPA (1992) surveys. Thirty
sightings of a total of 56 finback whales were recorded from 1980-83 (Dohl et al. 1983), with
70% of the sightings in continental shelf and slope waters. One finback whale was seen about
20 km west of Point Reyes, and a group of 5 to 8 whales were observed just south of the
Farallon Islands in 1981. Sperm whales are commonly found off central California, with peaks
of abundance in mid-May and mid-September suggesting a northward migration in the spring and
a southward migration in fall. From November to April, breeding groups are sighted over the
continental slope off California between 33° to 38°N latitude (Gosho et al. 1984). There were
66 sightings of a total of 218 sperm whales from 1980-83 (Dohl et al. 1983), with 68% of the
sightings in waters greater than 1,700 m deep. Four sperm whales were observed in Study Area
5 in 1983. Although the Gulf of the Farallones lies within the distributional range of sei and
right whales (Caldwell and Caldwell 1983), none were recorded during recent (Ainley and Allen
1992; Jones and Szczepaniak 1992) or historic (Dohl et al. 1983) surveys.
Other Cetaceans
Other species of cetaceans either have been sighted in the region, stranded along the mainland
coast, or have the potential for occurring in the region (Dohl et al. 1983). Killer whales are
widespread throughout the eastern north Pacific (Leatherwood and Reeves 1982). Dohl et al.
(1983) reported that killer whales ranged along the entire California coastline, occurring most
frequently over the continental slope north of Monterey Bay. A group of 5 to 8 killer whales
was seen west of the Farallon Islands near Study Area 5 in 1981 (Dohl et al. 1983). Beaked
whales, including Mesoplodon spp. and Berardius bairdi, are oceanic and occur worldwide.
3-210
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There are at least three species of Mesoplodon that could occur in the area: Hubb's beaked
whale (M. carlhubbsi), Blainville's beaked whale (M. densirostris), and Stejneger's beaked whale
(M. stejneger). Some species of Mesoplodon are recognized as deep divers (M. carlhubbsi in
particular) and feed on squid and midwater fishes. Baird's beaked whales (B. bairdi) occur from
the Bering Sea to Baja California, Mexico. Dohl et al. (1983) suggested that Baird's beaked
whales move onto the continental slope off central and northern California during June, then
move offshore in November; none were seen near the Gulf of the Farallones during the 1980-83
surveys. This species also is deep-diving and feeds on squid and octopuses as well as
crustaceans, sea cucumbers, and a variety of deep-sea and midwater fishes (Caldwell and
Caldwell 1983). Beaked whales generally avoid vessels, which may in part explain their reduced
numbers during surveys.
In summary, results from historic surveys (Dohl et al. 1983) indicated that for all cetaceans
combined, highest species densities occurred in Study Area 5. Moderate species densities
occurred in Study Area 3, and low densities were found in Study Areas 2 and 4. In contrast,
results from long-term marine mammal censuses (Ainley and Allen 1992) and recent seasonal
surveys (Jones and Szczepaniak 1992) indicated that more cetaceans occurred in Study Areas 3
and 4 (Table 3.3.5-2). In general, cetacean abundances within the study region appear highest
in slope and deeper waters.
3.3.5.2 Pinnipeds
Bonnell et al. (1983) censused the pinnipeds and southern sea otters of central and northern
California by means of monthly aerial transects and quarterly coastal censuses. They estimated
that the five predominant pinniped species, the California sea lion (Zalophus californianus),
harbor seal (Phoca vitulind), northern elephant seal (Mirounga angustirostis), northern fur seal
(Callorhinus ursinus), and northern sea lion (Eumetopias jubatus), had combined populations of
approximately 50,000 animals. Peak numbers at sea occurred in winter and spring with the
arrival of migrant northern fur seals from the Bering Sea. Northern sea lions, northern elephant
3-211
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Table 3.3.5-2.
Relative Densities of Marine Mammal Species Within the Four LTMS
Study Areas.
Data from A (Ainley and Allen 1992) and B (Jones and Szczepaniak 1992).
Cetacean Species
Pacific white-sided dolphin
Northern right whale dolphin
Risso's dolphin
Dad's porpoise
Harbor porpoise
Gray whale
Humpback whale
Blue whale
Minke whale
Pinniped Species
California sea lion
Northern elephant seal
Northern sea lion
Northern fur seal
Harbor seal
Study Area 2
A
N
N
N
L
I
N
L
N
N
L
L
N
L
L
B
N
N
N
L
N
N
L
L
N
N
N
N
N
N
Study Area 3
A
L
N
L
L
N
N
N
N
N
N
L
N
L
N
B
M
N
N
M
N
N
L
L
N
M
N
L
L
N
Study Area 4
A
M
N
L
N
N
N
L
N
L
N
N
N
L
N
B
N
N
L
N
N
N
N
N
N
N
N
N
N
N
Study Area 5
A
L
N
N
N
N
N
N
N
N
N
L
N
L
N
B
L
N
N
L
N
N
N
N
N
L
N
L
N
N
N = No mammals observed
L = Low density
M = Moderate density
AKOM5.W51
3-212
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seals, and harbor seals had large populations of approximately 3,000, 4,000, and 12,000
individuals, respectively.
The Farallon Islands are among the most important pinniped haul-out grounds in California
(Bonnell et al. 1983). The primary pinniped foraging grounds are the shallow shelf waters from
Point Reyes south in summer and fall, and deeper continental slope waters in winter and spring.
California sea lions and northern fur seals are present seasonally either along the coast or
offshore, and the northern elephant seal, harbor seal, and northern sea lion breed in the area
(Table 3.3.5-1). The Guadalupe fur seal (Arctocephalus townsendi) is considered an occasional
visitor to the area (Bonnell et al. 1983).
California Sea Lion
The California sea lion is the most common pinniped at California haul-out areas and in
continental shelf waters (KLI 1991). A few pups have been born on Southeast Farallon Island
(Pierotti et al. 1977; Huber et al. in prep.) and on Ano Nuevo Island (Keith et al. 1984) but
viable rookeries have not been established at either site. At sea, California sea lion relative
abundance is characterized by two peaks (May-June and September-October) which correspond
to peaks in abundance in haul-out areas. These peaks are due to the arrival and subsequent
departure of transient northern populations, with the highest at-sea mean seasonal density
(0.18/km2) recorded in fall (Bonnell et al. 1983). During this period, California sea lions feed
over Pioneer Canyon (between Study Areas 3 and 4) and Cordell Bank. Primary prey items
include crabs, squid, herring, hake, and mackerel (Ainley and Allen 1992). During the EPA
(1992) surveys, California sea lions were the most abundant pinniped in all seasons; the greatest
number of individuals were observed during August in slope waters near Study Area 3
(Figure 3.3.5-1 la). PRBO (1992) reported California sea lions as the second most common
pinniped of the region (following northern fur seals) occurring primarily along the continental
shelf including Study Area 2 (Figure 3.3.5-lib).
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Marine Mammal Counts
O 1
O 2-10
11-100
101-1000
Haukxjt Site
38°N
37°30'N -
Cordell Bank /
National Marine /
Sanctuary
Transverse Mercator Projection
Scale
0 5 10 15 20
Cordell Bank
50m
Gulf of The Farallones
National Marine Sanctuary
Farallon
JL Islands
2500m
Alternative
San
Francisco
Bay
Alternative
Gumdnfo $ Site 3 \
Seamount
\ Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
-123°30'w
-123°w
-122°30'w
Figure 3.3.5-1 la. California Sea Lion Counts in the Gulf of the Farallones Region,
August 1990 and 1991.
Source: Jones and Szczepaniak 1992.
AK0116
3-214
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Marine Mammal Counts
O 1
Q 2-10
11-100
Haukjut Site
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary /
O
rdell Bank I
m I
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallo
National M^jpe Sanctuary
Alternative
SiteS
\Pioneer
ICanyon
Monterey Bay
Marine
Sanctuary
-123°30'w
-123°w
-122°30'w
Figure 3.3.5-llb. California Sea Lion Counts in the Gulf of the Farallones
Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0117
3-215
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Northern Elephant Seals
Northern elephant seals are present year-round in the study region and reach peak numbers in
haul-out areas during the spring (Bonnell et al. 1983). Their breeding range extends from Point
Reyes to Isla Cedros in Baja California (Le Boeuf et al. 1978) and includes a breeding colony
on Southeast Farallon Island. The greatest numbers of elephant seals near the study areas were
sighted near the Ano Nuevo and Farallon rookeries and in areas over the continental slope from
Point Reyes to Monterey Bay (Bonnell et al. 1983) where they feed primarily on squid, octopus,
hagfish, anchovies, and rockfish (Ainley and Allen 1992). The few northern elephant seals seen
during PRBO (1992) surveys were primarily over slope waters (Figure 3.3.5-12); EPA (1992)
censuses recorded five sightings over slope waters although no northern elephant seals were
observed in the LTMS study areas. Northern elephant seals may dive to depths of 1,500 m
(Ainley and Allen 1992) and often remain at the surface for less than one minute when feeding.
This may account for the few species sightings within the region (Le Boeuf et al. 1978).
Conversely, other pinniped species such as northern fur seals may rest at the surface for hours
(Gentry and Kooyman 1986) making them more likely to be observed during censusing.
Northern Sea Lion
Northern sea lion populations have declined since the 1940s and currently include about 3,000
individuals statewide (KLI1991). They are currently listed as a threatened species by the Federal
government. Northern sea lions usually are sighted in shallow waters from less than 1 km to 55
km offshore. Most are found in four areas within 45 km of the coast: (1) Cape Mendocino to
the Klamath River; (2) Cordell Bank; (3) north of Point Arena; and (4) the continental slope
between the Farallon Islands and Ano Nuevo Island. The largest northern sea lion rookery in
California is on Ano Nuevo Island and includes over 1,000 animals. A rookery of about 200
animals exists on Southeast Farallon Island; however, fewer than 30 pups are reported born per
year (Huber et al. in prep.). There is a minor haul-out area at Point Reyes Headland. Northern
sea lions feed primarily on squid, octopus, and fish such as smelt, flatfishes, and rockfishes
3-216
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Marine Mammal Counts
O 1
Haukxjt Site
38°N -
37030'N -
CordellBank /
National Marine/
Transverse Mercator Projection
Scale
0 5 10 15 20
Cordell Ban
50m
Gulf of The Farallones
NSThpnal Marine Sanctuary
x - j- San
Francisco
Bay
Alternative
Sites
Alternative
Gumdr&j 0Site3 \
Seamount
I Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
-123°W
-122°30lw
Figure 3.3.5-12. Northern Elephant Seal Counts in the Gulf of the Farallones Region, 1985-1991.
Source: Ainley and Allen 1992.
AK011B
3-217
-------
(Ainley and Allen 1992). Northern sea lions were observed twice during seasonal studies: once
each in Study Areas 3 and 5 (Figure 3.3.5-13a) (Jones and Szczepaniak 1992). Two individuals
were observed during the PRBO (1992) surveys, one northwest of the Gulf of the Farallones
National Marine Sanctuary and one along the coast south of Point Reyes (Figure 3.3.5-13b)
(Ainley and Allen 1992).
Northern Fur Seals
Northern fur seals are the predominant pinnipeds in waters seaward of the continental shelf
(greater than 200 m) in winter and spring, with an estimated 25,000-30,000 animals present off
central and northern California (Bonnell et al. 1983). They are designated as a depleted species
by the Marine Mammal Commission. A few individuals haul out on Ano Nuevo Island and the
Farallon Islands (Le Boeuf and Bonnell 1980; Huber et al. in prep.). Although the species occurs
year-round in the study region, it is considered primarily a winter-spring pelagic visitor to the
area (Bonnel et al. 1983; KLI 1991). Their numbers increase in abundance offshore with the
arrival of northern migrants in the winter. Most return to their Bering Sea rookeries in late
spring (York 1987) or to rookeries on San Miguel Island in southern California. Northern fur
seals consume a variety of prey including crabs, squid, sablefish, anchovies, and rockfish (Ainley
and Allen 1992). Within the study region, northern fur seals were the second most frequently
observed pinniped during seasonal surveys (Jones and Szczepaniak 1992) and the most common
pinniped during June 1985-91 surveys (Ainley and Allen 1992). Northern fur seals were seen
within Study Area 3 and near Study Areas 4 and 5 during EPA (1992) surveys
(Figure 3.3.5-14a). During June 1985-91, northern fur seals were seen in low numbers within
all of the study areas, although the greatest concentrations were found north and west of Study
Area 5 (Figure 3.3.5-14b).
In general, pinniped sightings were rare within the study areas (Ainley and Allen 1992; Jones and
Szczepaniak 1992). Table 3.3.5-2 presents a summary of pinniped occurrences within the four
study areas. These results in conjunction with actual sightings as shown in Figures 3.3.5-1 la
through 3.3.5-15 indicate that the slope waters of Study Areas 3 and 5 support the highest
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Marine Mammal Counts
O 1
Haukxjt Site
38°N -
37°30'N -
Cordell Bank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marine Sanctuary
200m*
Farallon
. 4 Islands
San
Francisco
Bay
Aternative . , ^
Site 5 kmz/ ^
9\ Study
f \ Area 5
Alternative
SiteS
»Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
-123°30'w
-123°w
Figure 3.3.5-13a. Northern Sea Lion Counts in the Gulf of the Farallones Region,
August 1990 and 1991.
Source: Jones and Szczepaniak 1992.
AK0119
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Marine Mammal Counts
O
Haul-out Site
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary /
Transverse Mercator Projection
Scale
0 5 10 15 20
Cordell Bank
50m
Gulf of The Farailones
National Marine Sanctuary
200m
500 m\\^ Farallon
. i Islands
.San ,
Francisco
San
Francisco
Bay
Alternative
SiteS
\ Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
Quid
Seamhunt
-123°30>w
-123°w
-122°30'w
Figure 3.3.5-135. Northern Sea Lion Counts in the Gulf of the Farailones Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0120
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Marine Mammal Counts
O 1
O 2-10
Haul-out Site
38°N -
37°30'N -
CordellBank /
National Marine /
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marine Sanctuary
200m
Farallon
.. Islands
San
Francisco
Bay
Alternative
Sites
I Pioneer
iCanyon
Monterey Bay
National Marine
Sanctuary
-I23030'w
-123°w
-122°30'w
Figure 3.3.5-14a. Northern Fur Seal Counts in the Gulf of the Farallones Region,
August 1990, February, May, August, November 1991.
Source: Jones and Szczepaniak 1992.
AK0121
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Marine Mammal Counts
O 1
O 2-10
11-100
Haul-out Site
38°N
37°30'N
CordellBank /
National Marine /
Sanctuary I
I
I
I
Transverse Mercator Projection
Scale
0 5 10 15 20
O ....-
Gulf of The Farallones
I Marine Sanctuary
'200m
Farallon
Alternative ,.
Sites IJI
PJbnedr
e amount
Monterey Bay
National Marine
Sanctuary
-123°30'w
-123°w
-122°30'w
Figure 3.3.5-14b. Northern Fur Seal Counts in the Gulf of the Farallones Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0122
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concentration of pinnipeds. Of the five pinnipeds cited, four occurred most often in Study
Area 3. The remaining pinniped was the harbor seal which is rarely seen in deeper, slope waters
(KLI 1991).
Harbor Seals
Harbor seals are year-round residents of the central California coast, and haul out at islands,
secluded beaches, estuaries, and offshore rocks between Ano Nuevo and Point Reyes (Allen and
Huber 1983, 1984; Bonnell et al. 1983; Allen et al. 1986; Hanan et al. 1987). They forage close
to shore, feeding on crabs, squid, smelt, mackerel, and rockfish (Ainley and Allen 1992), and
rarely are seen in water deeper than 180 m (KLI 1991). Harbor seals are locally migrant and are
seasonally most abundant onshore during the spring breeding season (March-June) and the
summer molt (June-August). They rest onshore almost daily but spend more time on land during
early spring and winter months, averaging 17 hours per day on land (Allen et al. 1987). During
PRBO (1992) surveys, most harbor seals (80%) were seen over continental shelf waters, in and
around Study Area 2 (Figure 3.3.5-15). No harbor seals were observed during the seasonal
survey effort (Jones and Szczepaniak 1992).
3.3.5.3 Fissipeds
Southern sea otters are common to the general study region, but occur primarily along the
mainland south of Point Ano Nuevo to Point Conception (Bonnell et al. 1983). Sea otters
normally reside nearshore (within 2,000 feet of shore) and feed on shellfish and fish (Siniff and
Rails 1988). Recently, there have been major, unpredictable shifts in their distribution along the
coast. According to the California Department of Fish and Game (CDFG), a group of 11 to 25
otters was observed several times north of Ano Nuevo between September 1986 and April 1987.
In October 1986, a single sea otter was observed for a four-day span at the Southeast Farallon
Island (PRBO, unpubl. data). Incidental sightings also occur annually along the Point Reyes
peninsula (PRBO, unpubl. data). Sea otters were not observed near any of the proposed study
areas during recent survey efforts (Ainley and Allen 1992; Jones and Szczepaniak 1992). Their
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Marine Mammal Counts
O
2-10
Haukmt Site
38°N -
37°30'N -
CordellBank /
National Marine /
Sanctuary
Transverse Mercator Projection
Scale
0 5 10 15 20
Cordell Ban
50m
Ch
Gulvof The Faiallones
National Marin^^anctuary
200m
500 m Fara
San
Francisco
Bay
Alternative
SiteS
Alternative
Site3
i Pioneer
iCanyon
nterey Bay
National Marine
Sanctuary
Guid
Seambunt
-123°30'w
-123°w
-122°30'w
Figure 3.3.5-15. Harbor Seal Counts in the Gulf of the Farallones Region, 1985-1991.
Source: Ainley and Allen 1992.
AK0123
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typical habitat is rocky intertidal and kelp bed areas (Ainley and Allen 1992) which suggests that
their presence is unlikely within any of the deep, slope waters of the LTMS study areas.
3.3.6 Threatened, Endangered, and Special Status Species
This section presents information on threatened, endangered, and special status species that occur
within the LTMS study region. Species that occur regularly, and species that occur rarely in the
study region are discussed in separate sections.
3.3.6.1 Species Observed Regularly Within the Study Region
Nine known threatened or endangered species regularly occur in the general study region. These
include five whale species (gray, humpback, blue, finback, and sperm), one pinniped (northern
sea lion), two bird species (Peregrine falcon and California brown pelican), and one fish species
(winter-run chinook salmon). The current status of these species under the Federal Endangered
Species Act (ESA) and the State of California endangered or protected species list is summarized
in Table 3.3.6-1. The ESA coordination process will occur concurrently with the review of the
draft EIS and the preparation of the final EIS. Coordination information will be included in the
final EIS. Formal consultation letters (see Chapter 5) requesting advisement of (1) the presence
of any listed or candidate, threatened, or endangered species, and (2) any critical habitat of these
species that may be impacted by dredged material disposal, within the four LTMS study areas
were submitted to the Fish and Wildlife Service, National Marine Fisheries Service, and the
California Department of U.S. Fish and Game as required by the Endangered Species Act Section
7(c).
The species listed in Table 3.3.6-1 are subject to full protection under the Federal ESA (see
Section 1.6.2.7). The ESA prohibits the take of any listed species, generally defined as
prohibiting any harassment, harm, pursuit, hunting, shooting, wounding, killing, trapping, capture,
collection, or attempts at such conduct. In addition to the ESA, marine mammals are protected
by the Marine Mammal Protection Act which established a moratorium on the taking or
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Table 3.3.6-1.
Threatened or Endangered Species Occurring in the Study Areas
(modified from KLI 1991).
Common Name
Scientific Name
Status
Cetaceans
Gray Whale
Humpback Whale
Blue Whale
Finback Whale
Sperm Whale
Eschrichtius robustus
Megaptera novaeangliae
Balaenoptera musculus
Balaenoptera physalus
Physeter macrocephalus
FE
FE
FE
FE
FE
Pinnipeds
Northern Sea Lion
Eumotopias jubatus
FT
Marine Birds
Peregrine Falcon
California Brown Pelican
Falco peregrinus
Pelecanus occidentalis calffornicus
SE, FE
SE, FE
Marine Fishes
Winter-run Chinook Salmon
Oncorhyncus tshawytscha
SE, FT
FE = Federally listed endangered
ST = State listed threatened
FT = Federally listed threatened
SE = State listed endangered
Note: Additional threatened, endangered, or candidate species that occur rarely within the study region
are discussed later in Section 3.3.6.
AK0046.W5I
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importing of marine mammals or marine mammal products. One of the Act's management
requirements seeks to attain an "optimum sustainable population" for all marine mammal species,
including additional protection of those populations considered depleted.
NMFS is responsible for the protection of cetaceans, pinnipeds, and fishes, while FWS is charged
with responsibility for protection of birds. CDFG has jurisdiction over endangered or threatened
species in State waters.
Details on the biology and distributions of the eight species observed within the study region are
provided in Sections 3.3.5 (Marine Mammals), 3.3.4 (Marine Birds), and 3.4.1. (Commercial
Fisheries). A brief summary of species occurrence (based on historic surveys and recent annual
and seasonal censuses) within the four Study Areas is presented below.
Cetaceans
Gray whales generally migrate twice annually through the study region (Table 3.3.5-2), although
currently they are observed year-round in central California (Ainley and Allen 1992) and have
been observed summering (Dohl et al. 1983; Huber et al. 1986) and overwintering (PRBO
unpubl. data) around the Farallones. Three sightings of gray whales were made during annual
surveys conducted during late spring from 1985-91 (Ainley and Allen 1992). All of the sightings
occurred within the GOFNMS; highest counts (11-100 individuals) were observed near the
northeast border of Study Area 5 (Figure 3.3.5-7) (Ainley and Allen 1992). No gray whales were
observed during similar surveys conducted over four seasons in 1990-91, although this was likely
due to the fact that most of the areas surveyed during the months of high migratory activity were
over deep waters, where gray whales are rarely seen (Jones and Szczepaniak 1992).
Humpback whales typically are found in the study region from March through January with
greatest concentrations occurring from mid-August through October (Dohl et al. 1983; Baker et.
al. 1986; Calambokidis et al. 1990a). Annual surveys conducted June 1985-1991 (Ainley and
Allen 1992) recorded the greatest abundances (2-10 individuals) near the southeast corner of
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Study Area 2 and between Study Areas 3 and 4 (Figure 3.3.5-8b). In contrast, August surveys
(Jones and Szczepaniak 1992) recorded similar numbers of individuals within Study Area 3 and
the region between Study Areas 2 and 3 (Figure 3.3.5-8a).
Similar to humpback whales, the greatest abundances of blue whales within the Farallon Basin
occur in summer and early fall, although overall numbers are lower than those of humpback
whales (Dohl et al. 1983). Studies conducted from 1986-1989 identified a total of 179 blue
whales within the Gulf of the Farallones (Calambokidis 1990b). In 1986, an aggregation of 41
blue whales was sighted near Southeast Farallon Island (National Marine Sanctuary Program
1987). Recent seasonal studies (Jones and Szczepaniak 1992) recorded blue whales between
Study Areas 2 and 3 and within Study Area 3, with greatest abundances along the continental
shelf break (Figure 3.3.5-9).
During their 1980-83 survey, Dohl et al. (1983) recorded 30 sightings of 56 finback whales,
primarily over continental shelf and slope waters. In addition, this survey observed a group of
five to eight finbacks just south of the Farallon Islands, and a single individual approximately
20 km west of Point Reyes. No finback whales were sighted within the region during recent
annual (Ainley and Allen 1992) and seasonal surveys (Jones and Szczepaniak 1992).
Dohl et al. (1983) characterized sperm whales as regular visitors to the Gulf of the Farallones,
with records of 66 sightings for a total of 218 individuals from 1980-83. Most of the sightings
occurred in deeper waters (> 1700 m); four individuals were sighted in Study Area 5. Although
sperm whales historically were listed as the sixth most common cetacean in the region, recent
surveys recorded no sightings of this species (Ainley and Allen 1992; Jones and Szczepaniak
1992).
Pinnipeds
Due to a recent reduction in their numbers, northern sea lions were listed as threatened under the
ESA. Although this species is one of three pinniped species that breeds in the region, few
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sightings were made during recent surveys (Ainley and Allen 1992; Jones and Szczepaniak 1992).
Ainley and Allen (1992) recorded two sightings of single individuals, one near Cordell Bank and
one nearshore within the eastern boundary of the GOFNMS. Similarly, Jones and Szczepaniak
(1992) sighted only two individuals, one on the eastern boundary of Study Area 3 and one at the
western boundary of Study Area 5.
Although currently not listed as endangered or threatened, the northern fur seal is considered
depleted under the Marine Mammal Protection Act. It is found primarily over the continental
slope and was the most abundant pinniped species in the study region during June surveys
(Ainley and Allen 1992). During these surveys, low densities of northern fur seals (0.01-10
seals/km2) were observed in all of the study areas, but mostly in Study Areas 3 and 5. Jones and
Szczepaniak (1992) listed northern fur seals as the second most frequently sighted pinniped.
Similar to Ainley and Allen (1992), most sightings occurred over the continental slope, although
almost half of the sightings occurred west of the study areas (Jones and Szczepaniak 1992).
Birds
Peregrine falcons are Federally and State listed as endangered species. They are considered rare
in the region, but historically bred on the Farallon Islands (DeSante and Ainley 1980). Currently,
a relatively high number of individuals (5-8) continue to winter on the Islands (PRBO, unpubl.
data). During winter/spring NMFS cruises, two Peregrine falcons were observed foraging over
waters north and west of the Farallon Islands (PRBO, unpubl. data). No Peregrine falcons were
observed during annual or seasonal surveys (Ainley and Allen 1992; Jones and Szczepaniak
1992).
Although currently Federally and State listed as endangered, California brown pelican populations
appear to be recovering (Ainley and Allen 1992). Large numbers of pelicans roost at various
sites within the general study region including the Farallon Islands (Pyle and Henderson 1991)
and coastal mainland sites (Shuford et al. 1989). Recent annual surveys (Ainley and Allen 1992)
suggest that pelican populations are concentrated nearshore, over waters shallower than 180 m
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(Figure 3.3.4-5). Seasonal surveys (Jones and Szczepaniak 1992) also concluded that abundances
were greatest over continental shelf and upper slope waters.
Fishes
A dramatic reduction in winter-run chinook populations over the past two decades has led to its
listing as a threatened species by the Federal government and as an endangered species by the
State of California.
Winter-run chinook salmon are an anadromous species that pass through the Delta, San Pablo
Bay, and San Francisco Bay during their upstream and downstream migrations (J. Turner, CDFG,
pers. comm. 1991). Although this species is the least abundant Pacific salmon, it has the highest
value per pound and is fished commercially in North America from Kotzebue Sound, Alaska, to
Santa Barbara, California (Emmett et al. 1991). Juveniles of the species are ocean-dwelling and
occur primarily over continental shelf waters (Fredin et al. 1977). Commercial fish block data
for the study region (MMS/CDFG Commercial Fisheries Database 1992) indicate highest
abundances of salmon including winter-run chinook are caught within shelf regions such as Study
Area 2 (Figure 3.4-3).
3.3.6.2 Species Occurring Irregularly Within the Study Region
In addition to the species listed in Table 3.3.6-1, several other species that are currently listed
as endangered, threatened, or are candidates for special legal status occur irregularly within the
study region.
Cetaceans
Sei and right whales currently are listed as endangered under the Federal ESA. Although the
Gulf of the Farallones lies within the distributional range of both species (Caldwell and Caldwell
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1983), neither were observed during historic surveys (Dohl et al. 1983) or during recent survey
efforts (Ainley and Allen 1992; Jones and Szczepaniak 1992).
Pinnipeds
The Guadalupe fur seal (Arctocephalus townsendi) is considered a threatened species by Federal
and State agencies. Currently, this species is known to breed only at Guadalupe Island, Baja,
Mexico; sightings have been restricted to waters south of the Channel Islands (Bonnell et al.
1978). Historic estimates include approximately 2,000 individuals (Fleischer 1978). Guadalupe
fur seals are believed to be pelagic throughout most of the year except during the summer
breeding season. Although this species was not observed during recent annual and seasonal
surveys (Ainley and Allen 1992; Jones and Szczepaniak 1992), it may be a rare visitor to
regional waters (KLI 1991).
Fissipeds
The Southern sea otter is a geographic variant of the Alaskan otter (Kenyon 1987), and was
Federally listed as threatened in 1977. Its distribution ranges from Point Ano Nuevo south to
Pismo Beach (Jameson 1989). Although no sightings of the Southern sea otter were made within
any of the study areas (Ainley and Allen 1992; Jones and Szczepaniak 1992), one was recorded
near Point Ano Nuevo, the northern extent of its range (Ainley and Allen 1992). Southern sea
otters typically inhabit rocky intertidal and kelp bed areas (Ainley and Allen 1992). Thus, it is
unlikely that they would be present within any of the deep, slope waters of the LTMS study
areas.
Birds
The short-tailed albatross is also a Federally endangered species. According to Ainley and Allen
(1992), only two individuals have been sighted in the study region, although historically the
short-tailed albatross was a common species in offshore waters of the North American West
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Coast. Of the two individuals sighted within the region, one was seen at Cordell Bank and the
other in Monterey Bay (PRBO, unpubl. data).
In addition, the American osprey (Pandion haliaetus) is Federally and State listed as endangered.
This species is a breeding, year-round resident of the general coastal region (Ainley and Allen
1992). A small population (approximately 100 individuals) of American osprey nest at a coastal
site in Marin County (Ainley and Allen 1992). Osprey typically forage close to shore, and thus
are rarely observed farther than a few kilometers from the coast (Ainley and Allen 1992). No
osprey were observed within any of the study areas during recent annual and seasonal surveys
(Ainley and Allen 1992; Jones and Szczepaniak 1992).
The marbled murrelet (Brachyramphus marmoratus) has special status within California as a
candidate threatened species. Similar to the osprey, this species rarely forages farther than three
to five kilometers offshore (Ainley and Allen 1992) and was not observed within any of the study
areas during annual or seasonal surveys (Ainley and Allen 1992; Jones and Szczepaniak 1992).
Turtles
The leatherback sea turtle (Dermochelys coriaced) is the most frequently sighted marine turtle
within northern and central California (Dohl et al. 1983). This species currently is Federally
listed as endangered. During recent seasonal surveys (Jones and Szczepaniak 1992), two
sightings, each of a single leatherback turtle, were made. The first sighting occurred in shallow
water (54 m depth) north of Study Area 2, while the second observation was at approximately
1,000 m depth, northeast of Study Area 4. Both sightings occurred in August, consistent with
Dohl et al. (1983) findings of highest leatherback abundances during summer and fall months.
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3.3.7 Marine Sanctuaries and Special Biological Resource Areas
Six areas are designated as marine sanctuaries, refuges, or special biological resource areas within
the vicinity of the LTMS study areas. Four of these are Federally protected (GOFNMS,
CBNMS, MBNMS, and the Farallon National Wildlife Refuge), and two are protected by the
State of California (Farallon Islands ASBS and the Farallon Islands Game Refuge)
(Figures 3.3.7-1 and 3.3.7-2). Collectively, these six areas contain a wide diversity of sensitive
habitats and biological resources, including threatened or endangered species.
3.3.7.1 Federally Protected Areas
Sanctuaries
The Marine Protection, Research, and Sanctuaries Act of 1972 (MPRSA) was designed to protect
and manage discrete areas having special ecological, recreational, historical, and aesthetic
resources. The Gulf of the Farallones, Cordell Bank, and Monterey Bay National Marine
Sanctuaries (Figure 3.3.7-1) are three of eleven designated national marine sanctuaries. All
national marine sanctuaries are administered by NOAA's Sanctuaries and Reserves Division
(NOAA 1992).
Gulf of the Farallones National Marine Sanctuary. The GOFNMS encompasses 948 nmi2 of
nearshore and offshore waters, most of which lie in the Gulf of the Farallones. The Sanctuary
extends from approximately the western edge of the continental shelf (35 nmi offshore) to the
coasts of Marin and Sonoma Counties. Alternative Site 3 is over 10 nmi southwest of the
Sanctuary and more than 25 nmi southwest of the nearest Farallon Island. While Study Area 5
adjoins the western boundary of the Sanctuary, Alternative Site 5 lies nearly 25 nmi west of the
Farallon Islands. Study Area 2 begins at the southern boundary of the Sanctuary and lies entirely
within the MBNMS (Figure 3.3.7-1).
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38°N -
CordeJJBanli /
National Marine /
Sanctuary I
/
SOm I
Transverse Mercator Projection
Scale
0 5 10 15 20
Gulf of The Farallones
National Marine Sanctuary
Faratton
< Islands
San
Francisco
Bay
Alternative
Sites
isoom
fijf\ Study
Areas
Alternative
Gumdr^p Q Site 3 \
Seamount
Monterey Bay
National Marine
Sanctuary
-123030-w
-123°w
-122-30^
Figure 3.3.7-1. National Marine Sanctuaries in the LTMS Study Region.
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to
Noonday Rock
North Farallon
Middle Farallon
Maintop Island
Southeast Farallon
shaded Only Area of Special Biological Significance (CSWRCB)
sold omy Farallon National Wildlife Refuge (FWS)
shaded & Solid Farallon Islands Game Refuge (CDFG)
Source: Smith and Johnson 1989.
Figure 3.3.7-2. Farallon National Wildlife Refuge, Farallon Islands Area of Special Biological Significance,
and Farallon Islands Game Refuge.
-------
The selection of the GOFNMS as a sanctuary (January 26, 1981; 46 FR 7936) was based on the
high concentration of biological resources living within or migrating through its boundaries.
These resources include: (1) marine vegetation (particularly kelp, eelgrass, and salt marsh
species); (2) benthic fauna; (3) fish; (4) marine birds; and (5) marine mammals (NOAA 1980).
One of GOFNMS' most extensive resources is its marine bird population. The Farallon Islands
are the most important marine bird breeding site on the west coast of the continental United
States (Sowls et al. 1980; Briggs et al. 1987). There are sixteen species of marine birds known
to breed along the Pacific coast and twelve of these species have colonies on the Farallon Islands.
This group is comprised of the American black oystercatcher, Ashy storm-petrel, Brandt's
cormorant, Cassin's auklet, common murre, double-crested cormorant, Leach's storm-petrel,
pelagic cormorant, pigeon guillemot, rhinoceros auklet, tufted puffin, and western gull (Ainley
and Lewis 1974). The Farallon Islands serve as the nesting grounds for a significant portion (up
to 85%) of the world populations of Ashy storm-petrels, Brandt's cormorants, and western gulls
(Ainley and Allen 1992) as well as eighty percent of California's nesting Cassin's auklets
(California Coastal Commission 1987). In addition, California brown pelicans roost on the
Farallon Islands regularly and abundantly during summer and autumn. Endangered peregrine
falcons winter on the islands (NOAA 1980; Ainley and Allen 1992).
Aquatic birds also are found within the Sanctuary's lagoon, coastal bay, and four estuaries.
Breeding species include the American coot, cinnamon teal, gadwall, great blue heron, great
egret, killdeer, mallard, pied-billed grebe, and snowy plover. An additional twenty aquatic bird
species summer in the region, and seven species occur as spring and fall migrants (KLI 1991).
Marine mammals also are a significant part of the Sanctuary's biological resources. Twenty
species of whales and dolphins have been sighted in the Sanctuary, occurring either as migrants
or regular inhabitants (Table 3.3.5-1). Of these, Call's porpoise, harbor porpoise, and Pacific
white-sided dolphin are considered common resident species (Ainley and Allen 1992). Large
baleen cetaceans such as endangered blue, gray, and humpback whales are important migratory
species (Dohl et al. 1983).
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The Farallon Islands also serve as one of the most important pinniped haul-out grounds in
California (Bonnell et al. 1983). California's largest mainland breeding population of harbor
seals occurs within the Sanctuary, along with breeding herds of northern elephant seals and
northern sea lions (Ainley and Allen 1992). The threatened southern sea otter is an occasional
visitor to the Sanctuary (KLI 1991).
Cordell Bank National Marine Sanctuary. CBNMS encompasses 397 nmi2 of ocean water
overlying the northernmost submerged seamount on the California continental shelf. The
CBNMS was designated a National Marine Sanctuary on December 4, 1990 (55 FR 4994).
Ocean depths within the Sanctuary range from 35 m (at the peak of the Bank) to 1,830 m.
Alternative Site 5 is located within approximately 10 nmi of Sanctuary boundaries
(Figure 3.3.7-1); however, the Bank itself is located over 20 nmi from the Site. Alternative Site
3 is located 30 nmi to the south of the Sanctuary.
The combination of upwelling, underwater topography, and the wide range of depths at Cordell
Bank provides for a highly productive environment with unique associations between subtidal and
deep-water species (NOAA 1989). Further, endangered or threatened marine mammal and reptile
species, including gray, blue, right, finback, sei, sperm, and humpback whales, Guadalupe fur
seals, northern sea lions, and green, loggerhead, leatherback, and Pacific Ridley sea turtles, as
well as the depleted northern fur seal, often are found at Cordell Bank. Due to its rich biological
diversity, Cordell Bank is used frequently by divers and fishermen (NOAA 1989).
Monterey Bay National Marine Sanctuary. The MBNMS (Figure 3.3.7-1) encompasses 4,024
nmi2, ranging from Marin County to Cambria (NOAA 1992). Portions of Study Area 3 and all
of Study Area 2 lie within the Sanctuary boundaries.
The MBNMS supports a high diversity of marine resources. Monterey Canyon and its associated
topographic features promote seasonal upwelling of nutrient-rich waters which support diverse
biological assemblages of plankton, algae, invertebrates, fishes, marine birds, sea turtles, and
marine mammals. Monterey Bay provides abundant prey items for many species of migratory
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marine birds. This area is an important habitat for winter populations of Ashy storm-petrel and
Cassin's auklet, among others. Several endangered species are observed regularly within the
Sanctuary. The endangered California brown pelican is observed throughout the Sanctuary and
along the coastline (Figure 3.3.4-5) (Ainley and Allen 1992; Jones and Szczepaniak 1992). Right
whales, with a world-wide population estimated near 200, have been seen in waters off Half
Moon Bay. In addition, the endangered gray whale has been found in high abundances in the
northernmost limits of the proposed sanctuary (NOAA 1992), including the vicinity of Study
Areas 2 and 3. A complete list of species present in the Sanctuary can be found in the Final
Environmental Impact Statement and Management Plan for the Proposed Monterey Bay National
Marine Sanctuary (NOAA 1992).
Highly sensitive nearshore and offshore resources within the Sanctuary include: commercial
fisheries, aquaculture operations, kelp harvesting, estuaries, sloughs, sandy beaches and rocky
intertidal habitats, and nearshore littoral habitats (NOAA 1992). The commercially important
Dungeness crab is harvested in local waters.
Wildlife Refuges
Farallon National Wildlife Refuge. The Farallon National Wildlife Refuge is maintained by the
U. S. Fish and Wildlife Service (FWS) and includes Noonday Rock, North, Middle, and
Southeast Farallon Islands, and Maintop Island (Figure 3.3.7-2). It is primarily a migratory
refuge for 12 species of marine birds (including auklets, cormorants, guillemots, murres, puffins,
and storm-petrels) but also serves as an important habitat for 5 species of pinnipeds (KLI 1991).
The Wildlife Refuge is approximately 20 nmi due east of Alternative Site 5 and 25 nmi northeast
of Alternative Site 3.
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3.3.7.2 State Protected Areas
Areas of Special Biological Significance
Areas of Special .Biological Significance (ASBSs) were designated under the California State
Water Resources Control Board Resolution No. 74-28 to provide special protection for biological
communities and important marine species. Waste discharges within these areas are prohibited
in order to preserve and maintain natural water quality.
Farallon Island Area of Special Biological Significance. The Farallon Island ASBS includes 2.2
nmi2 of waters surrounding but not including Noonday Rock, North, Middle, and Southeast
Farallon Islands (Figure 3.3.7-2), and Maintop Island (CSWRCB 1976). Within the ASBS are
a highly diverse intertidal community and abundant marine mammal populations, including
California and northern sea lions, elephant seals, and harbor seals. Rare and endangered species
such as the California brown pelican, peregrine falcon, blue, gray, finback, humpback, sei, and
sperm whales also occur in the area (KLI 1991). The Farallon Island ASBS is approximately 20
nmi due east of Alternative Site 5.
Game Refuges
Farallon Islands Game Refuge. The Farallon Islands Game Refuge, under California Department
of Fish and Game (CDFG) jurisdiction, encompasses the Farallon Islands and Noonday Rock and
their surrounding waters extending 1 nmi from the coastline of each island (Smith and Johnson,
1989). It has an area similar to the combined areas of the Farallon National Wildlife Refuge and
Farallon Islands ASBS (Figure 3.3.7-2). The regulations governing the use of the Game Refuge
are coincident with those of the Wildlife Refuge and ASBS. The Farallon Island Game Refuge
lies 20 nmi east of Alternative Site 5 (Figure 1.3-1).
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Mainland Resource Areas
Other mainland coastal resource areas are located at least 30 nmi from the nearest alternative site.
Results from modeling the dispersion of dredged material (see Section 4.4) indicate that
sediments discharged at the alternative sites would not reach the mainland shore in detectable
quantities.
3.3.8 Potential for Development or Recruitment of Nuisance Species
Some changes in the distribution and abundance of local biological communities are expected
following any environmental disturbance, including dredged material disposal. Recolonization
and recovery of a disturbed area and the resultant species assemblage will depend on numerous
physical and biological interactions, including the size of the impacted area, the availability of
larvae and adults, biological interactions among colonizers, and the severity and frequency of
disturbance (Connell and Keough 1985; Lissner et al. 1991). Typically, recolonization of an
altered environment begins with opportunistic species and proceeds through time to more stable
communities typical of the surrounding area (EPA 1986).
Some organisms that may be present in dredged material or that may be favored after a
disturbance can be considered nuisance species. EPA defines nuisance species as "organisms of
no commercial value, which, because of predation or competition, may be harmful to
commercially important organisms; pathogens; or pollution tolerant organisms present in large
numbers that are not normally dominant in the area" (EPA 1986). These species can include
viruses, pathogenic bacteria, protozoans, fungi, invertebrates, and fish, or they may include the
eggs or spores of parasites that infect local fauna. In addition, in some environments dredged
material disposal may alter water quality or local sediments so that pollution-tolerant organisms,
normally occurring in low numbers, become the dominant species.
Dredged material disposal is unlikely to promote the development of nuisance species at any of
the alternative sites due to: (1) significant differences between dredging and disposal site depths
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and habitat characteristics and (2) permit restrictions for ocean disposal of dredged material. The
environment of the alternative sites consists of deep waters (depths > 1400 m) and thus is
expected to be very different, particularly in terms of dissolved oxygen, temperature, salinity,
pressure, food availability, and larval availability, than the relatively shallow dredging sites.
Therefore, the placement of shallow-water dredged material at sites of significantly greater depths
is not expected to result in colonization or propagation of shallow water nuisance species. All
dredged material proposed for disposal at the designated ODMDS must conform to MPRSA's
permitting criteria for acceptable quality. The acceptability of the material will be determined
by physical, chemical, and bioassay/bioaccumulation testing (EPA and COE 1991)
3.4 Socioeconomic Environment
This section presents information on the socioeconomic environment of the study region,
including commercial and recreational fisheries (Section 3.4.1), mariculture (Section 3.4.2),
shipping (Section 3.4.3), military usage (Section 3.4.4), mineral or energy development (Section
3.4.5), recreational activities (Section 3.4.6), and cultural and historical areas (Section 3.4.7).
3.4.1 Commercial and Recreational Fisheries
3.4.1.1 Existing Fisheries
The continental shelf and slope off San Francisco support a variety of commercial fisheries
including purse seine, dip net, trawl, hook and line, trap, gill net, and troll methods (Battelle
1989). The principal market species in this region include Dungeness crab, market squid,
salmon, tuna, flatfishes (Dover sole, petrale sole, and English sole), a variety of rockfishes
(Sebastes spp.; including shortbelly, widow, boccacio, chilipepper, splitnose and yellowtail),
thornyheads (Sebastolobus spp.), and sablefish (MBC 1989; Tetra Tech 1987). In addition to
primary market species, a number of other species including various species of sharks, tunas,
mackerels, and baitfishes such as Pacific herring (Clupea pallasii} have commercial value
(MMS/CDFG Commercial Fisheries Database 1992). Within the entire San Francisco region
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(from Point Arena to Point San Pedro, offshore to a distance of 200 nm; some of the most
productive commercial fisheries areas are in the Gulf of the Farallones, including the vicinity of
Study Areas 2 and 3 (MBC 1989; Oliphant et al. 1990). The estimated value of all major
commercial fisheries within the San Francisco region in 1986 totaled over $23,680,000 (Oliphant
et al. 1990; COE 1988). Figures 3.4-1 through 3.4-3 show the fisheries areas and describe the
commercially important megafaunal invertebrates and fishes collected in CDFG catch blocks
corresponding to each LTMS study area (including alternative sites).
Battelle (1989) concluded that fisheries resources of the continental shelf are of greater economic
value than those in deeper areas. SAIC (1992b) and MMS/CDFG Commercial Fisheries
Database (1992) found that some of the most productive areas were located in the deeper parts
of Study Area 2 and the shallow part of Study Area 3 (Figure 3.4-1).
Battelle (1989) indicated that three catch block groups had trawl landings in excess of 0.4 million
pounds (MP) in 1985. The first group (catch blocks 455 to 458 in depths less than approximately
100 m) had reported landings in 1985 of 0.58 MP, while the second group (catch block 475 in
depths between 200 and 600 m) had trawl landings of 0.40 MP (Battelle 1989). The third catch
block group (catch blocks 480, 481, and 482 at depths between 200 and 1,000 m) had reported
landings in 1985 of 1.5 MP.
Based on analysis of MMS/CDFG Commercial Fisheries Database (1992) information from 1970
through 1986, Study Area 2 lies entirely within an area of moderate to high fisheries resources
(0.5-72.5 MP; Figure 3.4-1), while the eastern (i.e., shallow) part of Study Area 3, on the upper
continental slope, is represented by highly productive fisheries resources (> 2.5 MP;
Figure 3.4-1). Study Area 4 represents an area of low to intermediate fisheries resources, with
between 0.5 and 2.5 MP taken from 1970 to 1986, while the least productive area within the
study region in terms of fisheries resources was Study Area 5 (0.5-1 MP).
The landings and catch block data must be interpreted with some caution because they represent
reported areas where fish were taken, and the accuracy of these data is difficult to verify. Fish
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38 CN
37C30'N -
Transverse Mercator Projection
Scale
10 15 20
Ł#456 V&
Alternative
SiteS
_469
Alternative
Gumdrop Q Site 3 \
Seamount
Alternative
Site 4
Guide
Seamount
-123°30'w
-123 °w
-122° SOVv
0-0.5 MP
>0.5-1 MP
>1-2.5MP
>2.5 MP
Figure 3.4-1. CDFG Commercial Fisheries Catch Blocks Showing Locations of Blocks
and Total Catches of Fishes and Invertebrates From 1978 to 1986 Within
the LTMS Study Areas. Total Catches are Given in Millions of Pounds (MP).
Source: MMS/CDFG Commercial Fisheries Database 1992.
AK0125
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TJ
c
I
o
o
rt
"rt
to
465 466 474 475 476 "477 482 "483 "460 "469
Study
Area 2
Study
AreaS
Study
Area 4
Study
AreaS
I Squids/Octopus
J2 Abalone
H Crabs
Ł2 Urchins
[3 Bivalves
g3 Shrimps
rm Snails
Catch Block Number
Figure 3.4-2. Commercially Collected Megafaunal Invertebrates (By Catch Block in Pounds)
Within the LTMS Study Areas between 1970 and 1986.
""Location of the Alternative Site.
Source: MMS/CDFG Commercial Fisheries Database 1992.
-------
10,000,000
K)
^.
Ui
t/)
Q
2
8
\
ID
CD
9,000,000-
8,000,000-
7,000,000-
6,000,000-
5,000,000-
4,000,000-
3,000,000-
2,000,000-
1,000,000-
0
1
465 466 474 475 476 "477 482 "483 "460 "469
Study Study Study
Area 2 Area 3 Area 4
Catch Block Number
Study
Areas
| Sharks/Skates/Rays
Q Rockfishes
H Flatfishes
0 Sablefish
Q Salmon/Trout
^ Tunas/Mackerels
Ł3 Baitfishes
QH Rattails
I] Hake
[g] Lingcod
[] Other
Figure 3.4-3. Commercially Collected Fishes (By Catch Block in Pounds)
Within the LTMS Study Areas between 1970 and 1986.
"""Location of the Alternative Site.
Source: MMS/CDFG Commercial Fisheries Database 1992.
-------
landed in a small portion of a given block may be extrapolated to the entire block or to groups
of blocks. Apparently unusual increases in the landings of a given species may actually represent
the first time a particular area was fished for that species. Another limitation is that the fishing
effort associated with the landings is not known for each catch block. For example, high catches
of flatfishes could represent high abundances from a few trawls or moderate catches from many
trawls.
The fishery resources for each study area are summarized in the following sections.
Study Area 2
Of the four LTMS study areas, the most significant commercial and recreational fisheries exist
on the continental shelf within Study Area 2. The total amount of all megafaunal invertebrates
collected commercially in the four primary catch blocks corresponding to Study Area 2 between
1970 and 1986 was over 29,000 pounds (Figure 3.4-2).
Commercially collected megafaunal invertebrates in these catch blocks include red urchins
(Strongylocentrotus franciscanus), market squid (Loligo opalescens), a variety of crabs (Cancer
spp; presumably including Dungeness crab, C. magister, although not specifically identified in
MMS/CDFG Commercial Fisheries Database 1992), abalone (Haliotis spp.), and various species
of bivalves including clams, mussels, and scallops (SAIC 1992b; MMS/CDFG Commercial
Fisheries Database 1992; Bence et al. 1992). Wild and Tasto (1983) also reported that a
significant fishery for Dungeness crab exists at depths centered between 36-64 m. The CDFG
Recreational Fisheries Database (1992) lists Dungeness crab as the only megafaunal invertebrate
taken in Study Area 2, although few individuals were collected.
Commercially collected fishes within the study area include lingcod (Ophiodon elongatus),
baitfishes such as Pacific herring, salmon, tuna, sablefish, various species of rockfishes, and a
variety of flatfish species including Pacific sanddabs (Citharichthys sordidus), Dover sole
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(Microstomus pacificus), rex sole (Errex zachirus), English sole (Pleuronectes vetulus), and
petrale sole (Eopsetta jordani; SAIC 1992b; MMS/CDFG Commercial Fisheries Database 1992;
Bence et al. 1992; Battelle 1989). The total amount of fish commercially taken in the four catch
blocks comprising Study Area 2 between 1970 and 1986 exceeded 19 million pounds
(Figure 3.4-3). Of these commercially targeted species, flatfishes, rockfishes, salmon, and tunas
represented the most important fisheries. Predominant fishes taken by recreational fishermen in
the same two catch blocks included rockfishes, salmon, tunas, and lingcod (CDFG Recreational
Fisheries Database 1992).
Study Area 3
Study Area 3 contains moderate to high commercial fisheries for both megafaunal invertebrates
and fishes in the shallow areas (Catch Block 476) but very limited fisheries in the deeper portions
(catch block 477) including Alternative Site 3 (Figures 3.4-2, and 3.4-3). Commercially collected
megafaunal invertebrates were virtually nonexistent within the entire study area (including
Alternative Site 3), with a total of less than 1,000 pounds taken from the two catch blocks
corresponding to this study area from 1970 through 1986 (Figure 3.4-2). Based on the
MMS/CDFG Commercial Fisheries Database (1992), a limited abalone fishery exists in the
deeper part of the study area, (catch block 477; Figure 3.4-2), although this may reflect reporting
or tabulation errors in the database. No megafaunal invertebrates were taken by recreational
fishermen in this study area (CDFG Recreational Fisheries Database 1992).
Commercially collected fishes included flatfishes (primarily Dover sole, rex sole, English sole,
and petrale sole), sablefish, rockfishes, and tunas. The total amount of fish taken in the shallow
parts of this study area exceeded 9 million pounds between 1970 and 1986 (Figure 3.4-3), with
flatfishes being the most predominant. Catches in the deeper part of the study area comprised
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migrating pelagic species such as tunas and mackerels (Battelle 1989). However, mackerels may
be caught in high numbers inshore using roundhaul nets (Jow 1992).
Study Area 4
Very limited commercial fisheries for megafaunal invertebrates existed in Study Area 4, including
Alternative Site 4, from 1970 through 1986 (Figure 3.4-2), probably due to difficulties with
fishing gear at these greater depths. No megafaunal invertebrates were taken by recreational
fishermen (CDFG Recreational Fisheries Database 1992). Commercial catches of fishes in the
shallow part of Study Area 4 (catch block 482, located shoreward of Alternative Site 4) were
represented by several species including flatfishes, sablefish, rockfishes, tunas, and mackerels
(Figure 3.4-3). In the deeper part of Study Area 4 (catch block 483), including Alternative Site
4, catches were substantially lower, with a total of approximately 600,000 pounds being taken
from 1970 through 1986. Flatfishes comprised almost 80% of this total. Very few species of
fishes such as sharks and tunas were taken by recreational fishermen in this study area (CDFG
Recreational Fisheries Database 1992).
Study Area 5
Based on available data, Study Area 5 is characterized by no megafaunal invertebrate fisheries
and a low to moderate commercial fisheries area for fishes (Figures 3.4-2 and 3.4-3).
Predominant fishes taken commercially include rockfishes, flatfishes, tunas and mackerels, and
sablefish (Figure 3.4-3). However, the region of Alternative Site 5 (Catch Block 469) is
characterized by the substantially lower fisheries resources. The primary recreational fisheries
in this study area are for pelagic species such as certain rockfishes, salmon, and tunas (CDFG
Recreational Fisheries Database 1992).
Detailed information on key existing fisheries species is presented below.
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Dungeness Crab
Because of its economic importance to commercial fisheries in central and northern California
(as well as Oregon, Washington, British Columbia, and Alaska), the population dynamics of the
Dungeness crab have been studied extensively (summarized in MBC 1987). Dungeness crabs
typically occur in depths from low tide to approximately 180 m, although they are most abundant
in inshore coastal waters (MBC 1987). Dungeness crab catches in the San Francisco region have
varied substantially over the years, with a peak catch of 8.9 million pounds in 1956-57 and a
sharp decline to a total of 700,000 pounds from 1980 to 1985 (COE 1988). In 1986, over 1.2
million pounds were taken in the San Francisco region, for a total value of over $2.3 million
(Oliphant et al. 1990). The Dungeness crab fishery continued to show a substantial recovery in
1987-1988 when 3.1 million pounds were taken in the San Francisco region. However, 1988-89
catch results indicated a decline of more than 50% from the previous year (CALCOFI 1990).
Pollution stress to juvenile stages has been suggested as a possible cause for such substantial
declines (Wainwright et al. 1992). Other suggested causes for population fluctuations may
include oceanographic factors (temperature and currents), overfishing, parasitism, predation, and
environmental degradation (Wild and Tasto 1983). Consequently, water quality monitoring and
habitat protection measures have been recommended by CDFG to protect this resource (Wild and
Tasto 1983). It is notable that Dungeness crab were uncommon in recent EPA trawl and ROV
surveys conducted in Study Area 2 (SAIC 1992b), primarily because they were not targeted by
bottom trawls. The MMS/CDFG Commercial Fisheries Database (1992) indicated market crabs
were collected in low numbers in catch blocks corresponding to Study Area 2 (Figure 3.4-2).
Market Squid
Market squid are fished commercially from Baja California to British Columbia, with major
fishing grounds located off central California (MBC 1989, 1987). Market squid typically are
collected using small purse-seines and dip nets. Historically, market squid have been an
important commercial fishery, representing one of the top five in California in terms of weight
harvested (MBC 1987). Between 1983 and 1985, an average of 467,000 pounds per year was
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harvested off California, while 1.8 million pounds were taken in 1986, representing a value of
almost $215,000 (Oliphant et al. 1990). Although the amount of market squid harvested is large,
the overall dollar value is low due to low market prices. Based on analysis of the MMS/CDFG
Commercial Fisheries Database (1992), market squid (combined with other squids and octopus)
represent a limited fishery in the general study region, occurring only at continental shelf depths
including Study Area 2 (Figure 3.4-2). Similarly, Bence etal. (1992) suggests that market squid
abundances are highest inshore, at depths less than 180 m. Market squid were collected as
incidental catch in Study Area 2 by SAIC (1992b); however, none were collected in any of the
other study areas or alternative sites.
Pelagic Fishes
The predominant pelagic fishes, defined as those species which spend all or part of their life in
the water column (Moyle and Cech 1988), of commercial importance are anchovies, herring,
juvenile rockfishes, and hake. Some species such as salmon and tuna can occur in large numbers
seasonally while migrating through the general study region (Oliphant et al. 1990).
Northern anchovy (Engraulis mordax) are distributed from British Columbia to the tip of Baja
California at the surface to depths greater than 300 m (Love 1991). Northern anchovies are a
major component of the commercial and baitfish fisheries in California. For example, anchovy
harvests have varied from 508,772 pounds in 1977 to over one million pounds in 1980 (Oliphant
et al. 1990). Between 1983 and 1985 an average of almost 830,000 pounds were taken, while
in 1986 approximately 865,000 pounds representing a total value of almost $92,000 were
collected in the San Francisco region (Oliphant et al. 1990). Bence et al. (1992) indicated that
juvenile northern anchovy were clearly most abundant in the shallow inshore areas such as Study
Area 2.
Pacific herring catches within the San Francisco region were consistently high from 1983 through
1985, averaging over 16 million pounds per year (Oliphant etal. 1990). The 16.4 million pounds
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collected in 1986 represented a value of almost $5.3 million. Pacific herring were collected by
SAIC (19925) in low numbers in Study Area 2, representing incidental catch. Similarly, the
MMS/CDFG Commercial Fisheries Database (1992) suggests that baitfishes (including Pacific
herring) were collected only in low numbers in the catch blocks corresponding to Study Area 2
(Figure 3.4-3).
Pacific hake (Merluccius productus) can occur in dense midwater schools and range in
distribution from the Bering Sea to Baja California at depths between 10 to 1,000 m (Love 1991).
However, this species is not normally targeted by recreational fishermen because of their deep
distributions, and is a smaller component of commercial fisheries in the San Francisco region.
SAIC (1992b) collected Pacific hake in low numbers using bottom trawls in Study Area 2 and
in adjacent Mid-Depth and Pioneer Canyon locations. Bence et al. (1992) concluded that Pacific
hake had their highest abundances at intermediate depths corresponding to depths such as the
shallow portions of Study Area 3 (i.e., not including Alternative Site 3). Although this species
is not currently taken in high numbers, it represents a valuable potential fishery.
Other pelagic species having considerable commercial value are salmon and tuna. Salmon
(chinook and coho) in the San Francisco region are a popular partyboat and commercial species,
normally trolled for at depths of up to 600 m (MBC 1989). In 1986, over 2.7 million pounds
of salmon were taken in the San Francisco region, accounting for a value of approximately $5.6
million. Albacore tuna (Thunnus alalunga), a valuable gamefish for recreational and sport
fishermen (MBC 1987), are most abundant from August through October (Squire and Smith
1977). In 1986, over 500,000 pounds of albacore, representing an estimated value of $326,000
(Oliphant et al. 1990), were taken in the San Francisco region.
Roundfishes
Roundfish fisheries in the San Francisco region are comprised primarily of lingcod, sablefish and
hake (discussed above). Lingcod (Ophiodon elongatus) typically occur in nearshore coastal
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environments from the Gulf of Alaska to Ensenada, Mexico (Love 1991). Juvenile lingcod are
primarily pelagic and distributed nearshore (Bence et al. 1992), while larger juveniles live near
the bottom over a variety of habitats including sand and gravel and eelgrass beds. Adults
typically are found on soft bottoms, moving into rocky areas as they grow older (Love 1991).
Lingcod are taken by sport and recreational fishermen as well as commercially. Between 1983
and 1985 an average of almost 860,000 pounds were taken in the San Francisco region. In 1986,
over 400,000 pounds representing a total value of almost $140,000 were taken in the San
Francisco region (Oliphant et al. 1990). During trawl surveys by SAIC (1992b), lingcod were
only collected in Study Area 2; however, these represented only low abundances of juveniles.
Sablefish (Anoplopoma fimbrid) occur from the inner shelf to depths of almost 3,000 m (Miller
and Lea 1972). Juvenile sablefish occur on the upper slope and shelf, while spawning adults
occur deeper than 1,000 m. The highest reported densities of sablefish are at depths between 324
and 990 m (Allen and Smith 1988). Sablefish are fished using trawls at depths between 73 and
1,000 m, while traps and longlines are used at deeper depths (between 384 to 1,262 m). Between
1983 and 1985 an average of almost 1.9 million pounds were taken in the San Francisco region,
while approximately 3.4 million pounds (a value of almost $1.4 million) were collected in 1986
(Oliphant et al. 1990). Sablefish were collected during trawl surveys by SAIC (1992b) in Study
Areas 2, 3, and 4; however, their abundances were highest in adjacent Mid-Depth and Pioneer
Canyon locations at depths between 252 to 1,170 m. No sablefish were collected by Cailliet et
al. (1992) in Study Area 5, including the Alternative Site 5 region.
Groundfishes
Landing data for groundfishes have a number of limitations including how certain groups are
classified. For example, chilipepper rockfish may be grouped in "rockfish", "chilipepper", or
"chilipepper/boccacio" categories. The accuracy of many of these landing reports must be
considered because numerous databases are available for analysis of commercial landings, and
there may be conflicting information contained within these databases.
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Groundfish fishery resources in the study region are diverse and comprised of a number of
rockfishes (primarily including shortbelly, widow, boccacio, canary, chilipepper, yellowtail, and
thornyheads), and flatfishes (Dover sole, petrale sole, English sole, rex sole, and sand sole). In
1987, commercial groundfish landings of more than 20,000 metric tons were recorded within the
Monterey International North Pacific Fisheries Commission (INPFC) Region, exclusive of foreign
fishing and joint ventures (Battelle 1989). Data on commercial groundfish resources for Study
Areas 2 through 5 primarily are taken from the MMS/CDFG Commercial Fisheries Database
(1992), while recreational catches are from the CDFG Recreational Fisheries Database (1992).
Rockfishes. The rockfish complex consists of a number of species (Sebastes spp. and
Sebastolobus spp.) collected from the middle continental shelf to areas deeper than 1,400 m;
however, most rockfishes are taken commercially at depths between 100 to 400 m (MBC 1987).
Most deepwater species of thornyheads (Sebastolobus spp.) are taken at depths between 90 to 800
m, although some have been fished at depths as great as 1,400 m (Allen and Smith 1988). The
most important rockfish species in terms of annual revenues to commercial fisheries are
chilipepper (Sebastes goodei), boccacio (S. paucispinis), splitnose (S. diploprod), yellowtail (S.
flavidus) and widow rockfish (5. entomelas). Widow rockfish catches reached their highest
total in 1982, with almost 12 million pounds collected representing a value of approximately $1.6
million (Oliphant et al. 1990). Oliphant et al. (1990) presents combined data for chilipepper and
boccacio. Chilipepper/boccacio catches from 1983 through 1985 averaged over 3.4 million
pounds, while in 1986 approximately 1.8 million pounds representing a value of $570,000 were
taken (Oliphant et al. 1990). SAIC (1992b) collected 12 species of rockfishes throughout the
study region. Chilipepper and shortbelly (S. jordani) had the highest abundances in Study
Area 2, as well as in adjacent Mid-Depth and Pioneer Canyon locations. Midwater trawls
conducted by Bence et al. (1992) indicated juvenile rockfish as a group were consistently most
abundant inshore, including depths similar to Study Area 2, but also were relatively abundant in
some offshore locations including the region of Study Area 5 and Alternative Site 5. In contrast,
abundances in Study Areas 3 and 4 were somewhat less, representing moderate to high numbers
(Bence et al. 1992).
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Flatfishes. Dover sole (Microstomus pacificus) comprise the largest flatfish fishery in the San
Francisco region. They are collected from the Bering Sea and Aleutian Islands southward to
central Baja California on the inner continental shelf to depths greater than 900 m, but primarily
are taken commercially in trawls at depths between approximately 300 and 900 m (Love 1991;
MBC 1987). In 1986, Dover sole landings in the San Francisco region totaled almost 6.3 million
pounds representing a value of over $1.6 million (Oliphant et al. 1990). Dover sole primarily
were collected by SAIC (1992b) within Study Areas 2 and the shallow parts of Study Areas 3
and 4 (not including Alternative Sites 3 or 4). The highest numbers of Dover sole collected by
SAIC (1992b) were in the Mid-Depth and Pioneer Canyon locations at depths ranging from 252
to 500 m.
Petrale sole occur from the Bering Sea southward to northern Baja California, but are most
abundant from southern California northward (Love 1991). They are taken at depths ranging
from intertidal to greater than 600 m, but are collected most often between 100 to 300 m. This
species is taken by sport and recreational fishermen, as well as by commercial trawlers. From
1983 to 1985, an average of nearly 400,000 pounds of petrale sole were taken in the San
Francisco region, while in 1986, almost 400,000 pounds representing a value of over $302,000
were taken in the same region (Oliphant et al. 1990). Bence et al. (1992) suggests that the
highest abundance of this species is at depths less than 180 m, corresponding to similar depths
as Study Area 2. SAIC (1992b) collected this species infrequently and in low numbers in Study
Area 2.
English sole are found from the Aleutian Islands to southern Baja California, with their
distribution centered from the Gulf of Alaska to southern California, at depths ranging from
intertidal to almost 600 m (Love 1991). Historical population centers of English sole in
California are located off San Francisco, Eureka, Fort Bragg, Monterey, and Santa Barbara (MBC
1987; Frey 1971). From 1983 to 1985 an average of over 700,000 pounds of English sole were
taken in the San Francisco region, while nearly 900,000 pounds representing a value of almost
$327,000 were taken in 1986. SAIC (1992b) collected this species in moderate numbers within
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Study Area 2. Consistent with their relatively shallow depth distribution, English sole were not
observed in Study Areas 3, 4, and 5.
Rex sole have a similar distribution as Dover sole and English sole and are taken at depths
ranging from intertidal to at least 900 m, but are most frequently collected at depths between 100
to 150 m (Love 1991). Although this species does not comprise a major part of the commercial
flatfish catch in the San Francisco region, an average of over 300,000 pounds were taken between
1983 and 1985, while over 400,000 pounds representing a value of almost $152,000 were taken
in 1986. Rex sole were collected by SAIC (1992b) in Study Area 2, as well as at adjacent
Mid-Depth and Pioneer Canyon locations. This species was not collected in any of the other
study areas. Bence et al. (1992) indicates that juvenile rex sole collected in midwater trawls had
the highest abundances in Study Area 5 relative to the other study areas. In contrast, bottom
trawls indicated adult rex sole were most abundant at depths between 100 to 500 m,
corresponding to depths such as Study Area 2 and the shallow part of Study Area 3 (Bence et
al. 1992).
3.4.1.2 Potential Fisheries
In general, limited fisheries currently exist in depths greater than 900 to 1,440 m (R. Lea, CDFG,
pers. comm. 1991). However, data on deep demersal fishes with fisheries potential are available
from studies conducted in other areas at similar depths (Pearcy et al. 1982; Stein 1985; Wakefield
1990). Currently, the only deep demersal species being targeted are various grenadiers (rattails).
Several fish species represent a potential future fishery resource. Potential or currently
underutilized species include shortbelly rockfish, Pacific sanddab, jack mackerel, ocean sunfish,
Tanner crab, king crab, rock crabs, krill, giant Pacific octopus, spiny dogfish, sea cucumber,
sheep crab, grenadier (rattails), hagfish, sharks, and skates (NMFS 1983; S. Kato, NMFS, pers.
comm. 1991). Shortbelly rockfish have been identified by NMFS Tiburon as an unexploited
fishery with major potential (Chess et al. 1988; Lenarz 1980). Bence et al. (1992) indicated high
3-255
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abundances of certain species of juvenile rockfishes in Study Area 5 which are an important
potential component to the commercial fishery in that area. Other less heavily fished species
include hagfish (Eptatretus spp.), for which a substantial trap fishery exists for their skins even
though these skins are of poor quality, fishing is difficult, and pay for fishermen is low.
Wakefield (1990) found black hagfish (E. deani) to be predominant along camera sled transects
off Point Sur from depths between 400 and 1,200 m, with a strong peak in abundance within the
600 m depth zone. Wakefield (1990) estimated that 82% of the total population of black hagfish
resided in this depth zone. Hagfish were collected infrequently within the entire study region and
only in Study Area 3 by SAIC (1992b) at approximately 1,000 m depth.
In summary, of the four LTMS study areas, Study Area 2 contains the most substantial
commercial fisheries resources and is considered by commercial fishermen to be a very
significant area (P. Parravano, Halfmoon Bay Fisherman's Association, pers. comm. 1991). The
area is dominated by market fishes such as rockfishes, flatfishes, salmon, and tuna. The shallow
parts of Study Areas 3 and 4 (not including Alternative Sites 3 and 4) contain some commercially
important species such as flatfishes, rockfishes, salmon, and tuna. The deeper parts of Study
Areas 3 and 4 (including Alternative Sites 3 and 4) and Study Area 5 have limited commercial
fisheries resources.
3.4.2 Mariculture
Several mariculture operations exist in nearshore embayments of the San Francisco Bay region.
These consist primarily of oyster culturing operations in Tomales Bay and Drakes Estero sites
leased from CDFG. However, these operations are located over 20 nmi from the nearest study
area (Study Area 2) and over 50 nmi from the alternative sites, and therefore are very unlikely
to be affected by use of any of the sites.
Mariculture activities in Tomales Bay consist of relatively small lease areas (4-120 hectares).
The majority of oysters raised and marketed are giant Pacific oysters (Crassostrea gigas) with
a commercial value in 1990 of over $800,000 (T. Moore, CDFG, pers. comm. 1992). The
3-256
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remaining mariculture species in Toraales Bay consist of European oysters valued at over
$5,000/yr and mussels valued at $18,000/yr in 1990 (T. Moore, CDFG, pers. comm. 1992).
Oyster culture in Drakes Estero represented approximately 30% of California's total commercial
crop in 1990 (T. Moore, CDFG, pers. comm. 1992). The primary lease in Drakes Estero covers
425 hectares and runs until 2015 (U.S. National Park Service 1976). The giant Pacific oyster is
the principal species cultured.
3.4.3 Shipping
Ships from six publicly used ports, 11 military installations, and several proprietary installations
use the 11 navigable waterways in the San Francisco Bay and Delta. It is estimated that
$5.4 billion of economic activity is directly dependent on deep and shallow draft navigation
channels in the San Francisco Bay and Delta regions (Ogden Beeman 1990). Commercial
shipping supports up to 35,000 full-time jobs, exclusive of jobs supported by Navy activities.
Movements of all types of vessels within the Bay have exceeded 61,000 per year since 1980, and
annual vessel movements in 1991 exceeded 86,000 (Table 3.4-1). A vessel movement is defined
as any occasion when a vessel enters San Francisco Bay from the Pacific Ocean, moves within
the Bay, or departs the Bay for the Pacific Ocean. The majority (81%) of these movements are
by small vessels such as ferries, tugs, and dredge barges and primarily involve transits within the
Bay.
The Coast Guard has established a Vessel Traffic Service (VTS) to reduce vessel collisions and
groundings and potential environmental or other resource damage that could result from such
incidents. As a safety measure, VTS has established precautionary zones and vessel traffic lanes
around major traffic intersections (see Figure 2.1-3). A precautionary zone 22.1 km in diameter
is located west of San Francisco Bay and facilitates safe vessel turning movements into and out
of the Golden Gate. VTS serves in an advisory capacity, coordinating and monitoring vessel
movements using commercial and surveillance radar as well as closed circuit television, and
utilizes a radio network to communicate information to inbound, outbound, and within the Bay
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Table 3.4-1. Total Vessel Transits in the San Francisco Bay Region, 1980-1991.
Vessel
Types
Commercial
Hazardous
Navy, Surface vessels
Coast Guard
Navy, Submarines
Foreign Navy
Tugs without Tows
Tugs with Tows
Deep Draft
Ferries
U.S. Government
Non-Channel 13
(Large Vessels
Not Using VTS)
Dredges
Tankers
Passenger Ships
TOTAL
1980
8102
58
669
1173
83
34
4176
13386
185
26467
0
1201
2669
3404
0
61607
1981
7191
93
847
4275
139
28
5076
16003
159
24993
0
1348
2309
3401
0
65862
1982
6516
87
850
4266
112
17
4919
17792
103
24008
0
1945
2638
2939
0
66192
1983
6633
81
892
2999
1333
60
5207
15812
135
28710
0
1415
2804
2904
0
67785
1984
7225
93
840
3578
146
30
4326
14978
152
28306
344
1735
2780
2664
100
67297
1985
6653
85
796
3567
87
34
3267
13504
158
31307
771
2036
7544
2374
146
72329
1986
5982
52
866
3411
97
26
2804
14139
180
41605
659
2061
6943
3194
213
82232
1987
6298
83
1227
5697
71
25
1611
14091
194
45564
830
1787
5270
3206
119
83073
1988
6090
79
1359
2096
67
40
1070
13507
219
45520
906
722
2813
3644
83
78215
1989
5761
95
2236
2572
67
45
868
13790
248
56036
935
532
2819
3907
65
89976
1990
5877
83
1913
1907
70
59
525
14553
205
58343
1081
310
2390
3684
70
91070
199t
5876
97
1823
1788
69
49
517
13081
700
56100
904
236
1914
3570
157
86891
u>
to
-------
vessels (Ogden Beeman 1991). Traffic data are maintained by vessel type for movements within
the Bay, but are not maintained for movements through the Golden Gate, in the precautionary
zone, or in the vessel traffic lanes. Approximately 38% of arriving and departing vessels use the
Northern Traffic Lane, 20% the Western, and 42% the Southern. The majority of tanker traffic
uses the Western Traffic Lane. The Coast Guard does not specifically track vessel traffic within
any of the LTMS study areas (Lt. Cmdr. Gibson, USCG VTS, pers. comm. 1992).
Movements through the Golden Gate account for only a small percentage (6.9%) of all vessel
traffic, although they represent a large percentage of the commercial cargo, Coast Guard, Navy,
tanker, and other large vessel movements. A summary by vessel type of the percentage of total
vessel movements that include transiting through the Golden Gate is presented in Table 3.4-2.
These movements represent approximately 99% of all military and commercial traffic, but very
few recreational vessel movements. Accurate transit data on recreational and small vessel,
including fishing vessel, movements is unavailable since they do not participate in the Coast
Guard's VTS (Lt. Cmdr. Gibson, USCG VTS, pers. comm. 1992). However, they are estimated
to be about 25 to 50 times the number of large commercial and military vessel movements. This
summary is based on the professional judgment of Coast Guard personnel, and reflects traffic
conditions during a typical year in the 1980's.
Vessels transporting dredged materials to a disposal site would traverse the traffic lanes shown
in Figure 2.1-3 and contribute to total traffic volume. Based on conservative assumptions of
approximately one barge-load every 12 hours (see Section 4.4), this would equate to
approximately 730 additional vessel transits. Given the rough or foggy conditions that may be
common in the study region (see Section 3.2.1), there is some small risk of collisions by towed
barges and hopper dredges within the Bay and the traffic lanes leaving the Bay. However,
historically the number of collisions or near collisions among vessels within and near San
Francisco Bay has been small. Collisions occurred an average of three times per year during that
time period, and represent a comparatively small number given the high overall traffic volume.
Overall, incidents of all types, including collisions, occurred an average of six times per year.
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Table 3.4-2.
Percentage by Category of Total Vessel Movements That Include
Transiting Through the Golden Gate.
Vessel Category
Commercial
Hazardous
Navy, Surface vessels
Coast Guard
Navy, Submarines
Foreign Navy
Tugs without Tows
Tugs with Tows
Deep Draft
Ferries
U.S. Government
Non Channel 13 (Large vessels not using VTS)
Dredges
Tankers
Passenger ships
Percentage
95%
80%
20%
5%
100%
100%
45%
5%
95%
0%
25%
5%
5%
45%
95%
SOURCE: Lt. Cdr. Gibson, USCG VTS, pers. comm. 1992.
AKOW8.W51
3-260
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Incidents involving tugs with barges or self propelled barges as recorded by VTS between 1980
and 1989 are presented in Table 3.4-3.
3.4.4 Military Usage
The San Francisco Bay region and adjacent Gulf of the Farallones represent a major area of
military usage, primarily by the U.S. Navy. Within the Bay, the Oakland Naval Supply Center
and Alameda Naval Air Station are major facilities (Navy 1992). The Alameda Naval Air Station
currently is used for homeporting two aircraft carriers, three cruisers, and one destroyer tender.
The Oakland Naval Supply Center is homeport to two replenishment oilers, one combat
replenishment ship, one naval hospital ship, and 28 Military Sealift Command Pacific ships.
Maintenance dredging of these facilities is needed to ensure that the berths are accessible to large
Naval vessels. The Navy's Third Fleet regularly utilizes the Gulf of the Farallones region for
offshore air, surface, and submarine operations. Naval activity within San Francisco Bay
averaged approximately 157 vessel movements (including submarines) per month in 1991 (Lt.
Cmdr. Gibson, USCG VTS, pers. comm. 1992).
The Navy maintains five submarine operating areas (U1-U5), located 45 to 56 km from the
Golden Gate (see Figure 2.1-4). Area U-l is not used regularly, while the remaining areas
receive moderate use (an average of 10 days per month). Submarine operating area use typically
is associated with trial diving exercises and equipment checkouts. The Navy would consider
dredged material disposal in these areas to be incompatible with submarine operations
(E. Lukjanowicz, U.S. Navy, pers. comm. 1991). Submarine transit lanes vary in width from 13
to 18.5 km and run parallel to the mainland and west of Bodega Head. The exact locations of
active transit lanes are periodically designated by the Navy in advisories to the Coast Guard
(E. Lukjanowicz, U.S. Navy, pers. comm. 1991). When lanes are active, other vessels in the
vicinity are warned against towing submerged objects within traffic lanes. The Navy also
conducts aircraft and surface vessel exercises, often in conjunction with submarine operations,
in an area that encompasses North Farallon Island and Noonday Rock along its southern
boundary. Activities include anti-submarine warfare training, air-intercepts, surface vessel
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Table 3.4-3. Incidents Involving Tugs, Barges, and Self Propelled Dredges Within and
Near San Francisco Bay, 1980-1989.
NATURE OF INCIDENT
Collision
Grounding
Material Failure
Foundering or Flooding
Barge Breakaway
Steering Failure
Disabled
Weather Damage
TOTAL
NUMBER OF OCCURRENCES
25
13
8
5
4
3
2
1
61
PERCENT
40.9
21.3
13.1
8.2
6.6
4.9
3.3
1.7
100.0
SOURCE: Ogden Beeman 1991.
AK0049.W51
3-262
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coordination, and dropping inert ordinance. These exercises typically represent 15 use-days per
quarter per year.
In addition to the Navy's activities, the USCG supports infrequent aerial overflight missions
throughout the area. The USCG conducts approximately five helicopter sorties per week around
the Farallon Islands for serial offshore enforcement purposes, and search and rescue missions are
conducted to a variety of destinations along the coast. The USCG also maintains a lighthouse
on Southeast Farallon Island, thus requiring regular flights of maintenance personnel from San
Francisco to the lighthouse post.
3.4.5 Mineral Or Energy Development
Large repositories of oil and gas reserves are located in several areas along and offshore of the
California coast (F. White, MMS, pers. comm. 1992). However, there are no oil and gas
development activities or structures within the general study region, and all the potential lease
areas are over 200 miles from the alternative sites. This is due to current moratorium schedules
and technological constraints which have limited oil and gas development to depths less than
approximately 300 to 400 m. Therefore, no significant mineral or energy development activities
are likely in the vicinity of the study areas and alternative sites. In addition, it is unlikely that
any mineral or energy development will take place within any of the marine sanctuaries that
cover a large area of the Gulf of the Farallones or in State waters (waters up to three miles from
the coast) (Kirk Walker, California State Lands Commission, pers. comm. 1992). The future of
outer continental shelf lease sales has been addressed recently by a Presidential Task Force on
oil and gas development (KLI 1991) but the results have not yet been published nor any
recommendations implemented.
3-263
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1987). Predominant fishes taken by recreational fishermen include rockfishes, king and chinook
salmon, tuna, and Dungeness crabs (CDFG Recreational Fisheries Database 1992).
Weather permitting, offshore tours to the GOFNMS are operated by Oceanic Society Expeditions
on each weekend day through the summer and fall months (June-September). Nature
organizations visit the Farallon Islands infrequently, conduct other commercial ventures, or
operate whale watching trips during the winter and spring migrations. On the average, over
10,000 people per year have participated in these tours between 1984 and 1992 (M.J. Schramm,
Oceanic Society Expeditions, pers. comm. 1992). Large numbers of bird watchers also made
boat trips to the GOFNMS and adjacent areas (greater than 2,500 people per year) to observe the
rookeries (MJ. Schramm, Oceanic Society Expeditions, pers. comm. 1992). The majority of
recreational traffic occurs on weekends. An average of five sailboats per month, mostly
originating from San Francisco Bay, have been observed in the vicinity of the Farallon Islands
(M.J. Schramm, Oceanic Society Expeditions, pers. comm. 1992). In addition, several motor boat
and sailing clubs use the Farallon Islands as a turning point during sponsored races that can occur
throughout the year (M.J. Schramm, Oceanic Society Expeditions, pers. comm. 1992).
3.4.7 Cultural and Historical Areas
Designation of the GOFNMS, the CBNMS, and the MBNMS is intended to preserve the natural
environment and to recognize the increasing "cultural" value placed on areas that are free from
the effects of technology. Wildlife tours are popular cultural events around the Farallon Islands.
Naturalist and zoological societies, such as the Audubon Society, conduct one or two tours
annually, and Oceanic Society Expeditions conducts a tour every Saturday and Sunday from June
to mid-November (MJ. Schramm, Oceanic Society Expeditions, pers. comm. 1992). Use of any
of the alternative sites should not significantly affect these activities beyond normal navigational
precautions.
No known man-made cultural or historical resources are located in the study areas and alternative
sites, based on a file review conducted of the California Archaeological Inventory, and a review
3-264
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of listings in the National Register of Historic Places and the California Inventory of Historic
Resources. Further, no known shipwrecks of cultural or historical significance are reported
within the study areas. According to the "Submerged Cultural Assessment" (which includes the
California region), published jointly by NOAA and the National Park Service, only one vessel
is located near Study Area 3. This is the aft portion of the PUERTO RICAN, which sank in
1984 one mile inside the boundary of the GOFNMS near the historical 100 Fathom site (located
at 37°30.3' N, 123°00.3' W). However, this vessel has little historic value (Delgado and Haller
1989).
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CHAPTER 4
ENVIRONMENTAL CONSEQUENCES
4.1 Introduction
This chapter assesses the significance of potential impacts of the proposed and alternative actions
on the physical, biological, and socioeconomic environments at the preferred and alternative sites.
Environmental consequences are evaluated separately for the preferred alternative (Section 4.2),
the No-Action Alternative (Section 4.3), and other ocean disposal alternatives (Section 4.4).
Site-specific impacts associated with dredged material disposal at the alternative sites are also
summarized and compared in Chapter 2 according to the five general and eleven specific criteria.
The significance of potential environmental impacts associated with each of the alternatives is
classified according to the following scheme (modeled after EPA 1988):
Class I: Significant adverse impacts that cannot be mitigated to insignificance.
No measures can be taken to avoid or reduce the adverse impacts to
insignificant or negligible levels.
Class n: Significant adverse impacts that can be mitigated to insignificance.
These impacts potentially are similar in magnitude to Class I impacts, but the
severity can be reduced or avoided by implementation of specific mitigation
measures.
Class IE: Adverse but insignificant impacts or no effects anticipated. No
mitigation measures are necessary to reduce the magnitude or severity of these
impacts.
Class IV: Beneficial effects. These effects could improve conditions relative
to existing or pre-project conditions. These can be classified further as
significant or insignificant beneficial effects.
4-1
-------
The term "significant" is used to characterize the magnitude of potential impacts; a significant
impact is defined as a substantial or potentially substantial change to resources in the vicinity of
or adjacent to a proposed ODMDS. In the following sections, the rationale for characterizing
potential impacts as significant or insignificant, distinctions between localized and regional spatial
scales of impacts, and the duration (short-term versus long-term) of these potential impacts are
identified. Associated mitigation measures are discussed where appropriate.
\
A summary of potential impacts on important resources of the physical, biological, and
socioeconomic environments of each alternative site is presented in Table 4.1-1. Resources for
which comparisons can be made among the alternative sites are addressed separately by site in
Sections 4.2 and 4.4. Resources or environmental conditions, such as ocean currents, which are
not affected by the proposed action are addressed genetically for all sites within each respective
section.
4.2 Preferred Alternative
This section describes the potential impacts of the proposed actions on the physical, biological,
and socioeconomic environments of the preferred alternative, Alternative Site 5. Potential
impacts of these actions on the environments of the other ocean disposal alternatives, Alternative
Sites 3 and 4, are addressed in Section 4.4.
Neither the preferred nor the alternative sites have been used previously for dredged material
disposal, and no specific data on the actual effects of disposal operations are available. Thus,
evaluation of potential effects on sea bottom and water column environments at the preferred and
alternative sites relies on modeling the initial deposition of dredged material and dispersion of
suspended particles and on information from studies conducted at existing ODMDSs. Where
possible, differences between the preferred and alternative sites in the magnitude of expected or
model-predicted spatial and temporal impacts are specified in this section and in Section 4.4.
4-2
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Table 4.1-1. Summary of Potential Environmental Impacts at the Preferred Alternative and Alternative Sites 3 and 4.
Description
Physical Environment
Air Quality
Water Quality
- Turbidity
- Dissolved Oxygen
- Pollutants
Geology
- Grain Size
- Sediment Quality
PREFERRED ALTERNATIVE
Alternative Site 5
Impact
Class1
III
III
III
III
1
III
Spatial
Extent4
R
R
L
L
L
L
Temporal
Extent3
S
E
E
S
E
E
Comment
Given that
material is
suitable quality
Given that
material is
suitable
quality
OTHER OCEAN ALTERNATIVES
Alternative Site 3
Impact
Class
III
III
III
III
1
III
Spatial
Extent
R
R
L
L
L
L
Temporal
Extent
S
E
E
S
E
E
Comment ^
Given that
material is suitable
quality
Given that
material is suitable
quality
Alternative Site 4
Impact
Class
III
III
III
III
1
III
Spatial
Extent
R
9
L
L
L
L
Temporal
Extent
S
E
E
S
E
E
Comment
Given that
material is
suitable quality
Given that
material is
suitable quality
1 Impact Class: I = Significant; II = Significant, but can be reduced by mitigation; III = Insignificant or none; IV = Beneficial.
2 Spatial Extent: S = Confined within site boundaries; L = Localized (up to 1 nmi outside of site boundaries); R = Regional (beyond 1 nmi from site boundaries).
3 Temporal Extent: S = Short term (less than or equal to 5 hours); E = extended (greater than 5 hours).
4 Potential interferences mitigated by specifying barge transit areas/Benefit of enhanced access in dredging areas.
5 NA = No known resources: Spatial and temporal extent of impacts not applicable.
6 Potential interferences near Farallon Islands mitigated by specifying barge transit areas.
AK0050.W51
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Table 4.1-1. Continued.
Description
Biological Environment
- Plankton
- Benthic Infauna
- Benthic Epifauna
- Demersal Fish
- Pelagic Fish
- Birds
- Mammals
- Threatened/
Endangered
PREFERRED ALTERNATIVE
Alternative Site 5
Impact
Class'
III
1
1
III
III
III
III
III
Spatial
Extent2
L
L
L
L
L
L
L
L
Temporal
Extent3
S
E
E
E
S
S
S
S
Comment
OTHER OCEAN ALTERNATIVES
Alternative Sits &
Impact
Class
III
1
1
III
III
III
III
III
Spatial
Extent
L
L
L
L
L
L
L
L
Temporal
Extent
S
E
E
E
S
S
S
S
Comment
Alternative Site 4
Impact
Class
III
1
1
III
III
III
III
III
Spatial
Extent
L
L
L
L
L
L
L
L
Temporal
Extent
S
E
E
E
S
S
S
S
Comment
1 Impact Class: I = Significant; II = Significant, but can be reduced by mitigation; III = Insignificant or none; IV - Beneficial.
2 Spatial Extent: S = Confined within site boundaries; L = Localized (up to 1 nmi outside of site boundaries); R = Regional (beyond 1 nmi from site boundaries).
3 Temporal Extent: S = Short term (less than or equal to 5 hours); E = extended (greater than 5 hours).
4 Potential interferences mitigated by specifying barge transit areas/Benefit of enhanced access in dredging areas.
5 NA = No known resources: Spatial and temporal extent of impacts not applicable.
$ Potential interferences near Farallon Islands mitigated by specifying barge transit areas.
AK0050.W51
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Table 4.1-1. Continued.
Description
- Sanctuaries
Socioeconomic Environment
- Fisheries
Commercial
Recreational
- Shipping
- Mineral
PREFERRED ALTERNATIVE
Alternative Site 5
Impact
Cfass1
II or III
III
III
III or IV
III
Spatial
Extent2
L
L
L
R
NA
Temporal
Extent3
S
E
E
E
NA
Comment
Potential effects
from spills
mitigated by
specifying barge
transit areas
Footnote 4
Footnote 5
OTHER OCEAN ALTERNATIVES
Alternative Site S
Impact
Class
II or III
III
III
III or IV
III
Spatial
Extent
L
L
L
R
NA
Temporal
Extent
S
E
E
E
NA
Comment
Alternative Site 4
Impact
Class
II or III
III
III
III or
IV
III
Spatiat
Extent
L
L
L
R
NA
Temporal
Extent
S
E
E
E
NA
Comment
' Impact Class: I = Significant; II = Significant, but can be reduced by mitigation; III = Insignificant or none; IV - Beneficial.
2 Spatial Extent: S = Confined within site boundaries; L = Localized (up to 1 nmi outside of site boundaries); R = Regional (beyond 1 nmi from site boundaries).
3 Temporal Extent: S = Short term (less than or equal to 5 hours); E = extended (greater than 5 hours).
4 Potential interferences mitigated by specifying barge transit areas/Benefit of enhanced access in dredging areas.
5 NA = No known resources: Spatial and temporal extent of impacts not applicable.
6 Potential interferences near Farallon Islands mitigated by specifying barge transit areas.
AK0050.W51
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Table 4.1-1. Continued.
Description
- Military Usage
- Recreational Usage
- Cultural/Historical
- Public
Health/Welfare
PREFERRED ALTERNATIVE
Alternative Site 5
Impact
Class'
III
II
II
III
Spatial
Extent*
S
R
R
L
Temporal
Extent3
S
S
E
E
Comment
Footnote 6
Footnote 6
OTHER OCEAN ALTERNATIVES
Alternative Site 3
impact
Class
III
III
III
III
Spatial
Extent
S
R
L
L
Temporal
Extent
S
S
E
E
Comment
Alternative Site 4
Impact
Class
III
III
III
III
Spatial
Extent
S
R
L
L
Temporal
Extent
S
S
E
E
Comment
OS
1 Impact Class: I - Significant; II = Significant, but can be reduced by mitigation; III = Insignificant or none; IV = Beneficial.
2 Spatial Extent: S = Confined within site boundaries; L = Localized (up to 1 nmi outside of site boundaries); R = Regional (beyond 1 nmi from site boundaries).
3 Temporal Extent: S = Short term (less than or equal to 5 hours); E = extended (greater than 5 hours).
4 Potential interferences mitigated by specifying barge transit areas/Benefit of enhanced access in dredging areas.
5 NA = No known resources: Spatial and temporal extent of impacts not applicable.
6 Potential interferences near Farallon Islands mitigated by specifying barge transit areas.
AK0050.W51
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Other sources of information concerning environmental impacts of dredged material disposal are
based almost exclusively on research and monitoring of nearshore, shallow-water sites. Effects
from dredged material disposal at deep-water sites are not well known. Of the more than 150
dredged material disposal sites in U.S. coastal waters, most are in water depths of less than 20 m
(EPA 1989). Some limited information on environmental consequences of dredged material
disposal in deep water areas is available. For example, information exists for the Yabucoa
Harbor, Puerto Rico, dredged material disposal site at depths between 377 and 914 m (Stoddard
et al 1985) as well as sites located off southern California in 100 to 300 m of water
(SAIC 1990a,b).
The following discussions of potential impacts are therefore based primarily on results of shallow
water disposal site studies and the environmental characteristics of the preferred and alternative
sites (see Chapter 3). Some of the impacts and processes occurring at these shallow water sites
can be extrapolated to deep water environments. However, the deep continental slope and rise
environment, within which the preferred and alternative sites are located, represents a unique
combination of geological, hydrographic, and biological features that must be considered when
evaluating the consequences of ocean disposal of dredged material in these environments.
Therefore, as appropriate, limits of present knowledge are identified along with the uncertainties
of extrapolating this information to the deep water environments of the LTMS study region.
4.2.1 Effects on the Physical Environment
These sections address potential effects of dredged material disposal at the preferred alternative
site on regional meteorology and air quality, physical oceanography, water quality, geology, and
sediment quality.
4-7
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4.2.1.1 Air Quality
Potential impacts to regional air quality associated with dredged material disposal operations at
the preferred alternative site were evaluated using an EPA air quality model. The model
assumptions and results are summarized in the following section.
Initial screening modeling was performed for carbon monoxide (CO), volatile organic compounds
(VOC), and oxides of nitrogen (NOX) to determine impacts to air quality. Effects from the
emissions of diesel engines on barge tugs were calculated using an EPA model (ISCST2) that
was designed to compute air pollutant concentrations from various types of emission sources.
EPA guidelines (EPA 19925) were followed for the modeling analysis.
Air pollutant emissions from barges during transit between the Oakland inner, outer, and middle
harbors and the preferred alternative site were modeled as eight, one km2 volume sources grouped
into one line source. The line source stretched from south of Treasure Island to a point 15 km
southwest of the Golden Gate Bridge and followed a path along the deep water shipping channel.
Initial dispersion coefficients and other related variables were determined following EPA
guidance (EPA 1992b).
Emission factors for barge tugs were taken from "AP-42, Compilation of Air Pollutant Emission
Factors" (EPA 1985). Other assumptions for barge tugs included a draft of 12 to 18 feet, 900
horsepower diesel engine, speed of 8 km/hr (4.3 knots), fuel consumption of 44 gal/hr, and 2
trips per day. Meteorological data were obtained from EPA's Office of Air Quality, Planning
and Standards Technology Transfer Network Bulletin Board System (OAQPS TTN). The surface
meteorological data were from San Francisco International Airport data for 1989 and the mixing
height data was from Oakland International Airport data for the same year.
The model calculated concentrations for a receptor grid that covers all of San Francisco and parts
of Sausalito, Berkeley, Alameda, and western Oakland. Concentrations of pollutants were
averaged for one hour, 24 hours, and one year. The model output tabulated the highest
4-8
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concentrations for each receptor and the highest ten concentrations within the grid for each
averaging period. These concentrations are compared to State and Federal ambient standards.
Table 4.2-1 presents the modeled concentrations and the regulated limits. Based on these model
results, no significant effects to air quality were indicated along the presumed route of the barges
transporting dredged material to the preferred alternative site. Therefore, effects from barge tug
emissions on air quality within the general LTMS study region are considered negligible, and use
of an ODMDS for dredged material disposal is estimated to represent a Class III impact.
4.2.1.2 Physical Oceanography
The proposed use of an ODMDS for dredged material disposal is not expected to have any
measurable effect on the regional or site-specific physical oceanographic conditions (Class III).
Instead, the prevailing oceanographic processes will strongly influence the dispersion and
long-term fate of dredged material discharged at the preferred alternative site. In particular,
currents will affect the dispersion of particles in the water column and subsequent water quality
conditions (discussed in Section 4.2.1.3), as well as settling and initial deposition of dredged
material on the sea floor (discussed in Section 4.2.1.4). Those oceanographic conditions that are
important to assessments of impacts on the physical, biological, and socioeconomic environments
are summarized below.
Although the circulation patterns over the continental shelf and slope areas of the study region
share some similarities with other regions of the California coast, there are specific current
patterns that are unique to this region (Section 3.2). These patterns include: (1) near-surface flow
over the slope that is more poleward than expected; (2) tidal effects which can be larger and
amplified at different frequencies than those in other areas; (3) the unique spatial pattern of the
California Undercurrent; and (4) a non-local source for the upwelled waters occurring on the
shelf (Section 3.2). All of these characteristics would affect the resuspension, dispersal, and
ultimate fate of dredged material deposited at the preferred and the alternative sites.
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Table 4.2-1. Model-Predicted Maximum Concentrations of Air Pollutants in Central San
Francisco Bay and the Corresponding Air Quality Standards.
The predicted maximum concentration represents the highest concentration within a receptor grid
from ambient concentrations plus project-related (dredged material barge transit) operations.
Pollutant
CO
NOX
VOC
Averaging
Period
1 hour
24 hour
Annual
1 hour
24 hour
Annual
kg/day
Predicted Maximum
Concentration
14.2 ng/m3 (0.012 ppm)
0.62 \ig/m3 (0.0005 ppm)
0.03 u.g/m3 (0.00003 ppm)
115 u.g/m3 (0.06 ppm)
5.0 ng/m3 (0.0027 ppm)
0.27 p,g/m3 (0.0001 ppm)
2.6 kg/day
Standard
California Federal
20 ppm 35 ppm
0.25 ppm1
0.053 ppm
68 kg/day
1Standard for NO2; the comparison assumes that all of the NOX is NO2.
AK0051.W51
4-10
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On the outer shelf, tidal and low frequency (subtidal) currents combine to generate currents near
the sea bottom with speeds greater than 45 cm/sec (Noble and Ramp 1992). These currents are
powerful enough to resuspend and transport fine sands. Therefore, any material containing fine
sand or smaller grain sizes can be moved by currents within this region in the direction of
predominant current flow. In addition, large currents from surface waves are expected to reach
the sea bed over the outer shelf. When surface wave currents combine with lower frequency
flows near the bottom, the erosive potential of the currents over the outer shelf is greatly
enhanced (Grant and Madsen 1979). The tendency for currents near the bottom to flow
poleward, especially during winter when large surface waves are generated by winter storms,
suggest that any fraction of dredged material deposited on the shelf eventually could move along
the isobaths into the GOFNMS.
Persistent poleward flow occurs in the upper 1,000 m of the water column over most of the year
(Section 3.2.2). This poleward flow is interrupted by equatorward events which can last as long
as a month. A strong seasonal pattern in the current regime was not apparent from recent EPA
studies (Noble and Ramp 1992). However, there was an abrupt transition to a less energetic
regime with more variable current directions from approximately the middle of August until
November, after which more energetic but intermittent poleward flow persisted through the
winter. There is evidence that the poleward flow is strongest over the inner slope at about 100 m
depth near Alternative Sites 3 and 4 but moves offshore to the north in the region of the
preferred alternative site. The inner slope currents offshore of the Farallon Islands are
particularly weak below the shallow surface layer. Currents below 800 to 1,000 m depth are
small magnitude, low frequency flows and are dominated by tides. Flows on the outer shelf
appear to be separated and unrelated to flows over the slope (Noble and Ramp 1992). The time
and space varying current field has a major influence on dispersion and deposition in deep water.
The local topography of a site is expected to cause enhanced flow and veering in the currents
near the bottom. Because enhanced tidal flows generally are stronger than subtidal near-bottom
currents, tidal movements represent the largest contributor to the erosive characteristics at the
different sites. The near-bottom currents at mooring Stations B and C, located near the southern
4-11
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boundary of Study Area 3, and mooring E, located in deeper water near the eastern boundary of
Study Area 5, had maximum current speeds between 37 and 43 cm/sec (Figure 3.2-2). Mooring
D, located to the south of Alternative Site 3, and F, located on the upper slope inshore from
Study Area 5, had relatively lower near-bottom tidal currents (see Section 3.2.2; Figure 3.2-2).
Thus, material deposited near Stations B, C, or E would be eroded more easily than material
deposited at Stations D or F. The near-bottom subtidal flow direction suggests that resuspended
material at Station B will be dispersed in both directions along the isobaths. Resuspended
material at Station C would be carried poleward, and resuspended material at Station E would
be carried eastward up the axis of a small, unnamed submarine canyon. However, because
Station E is in 2,000 m of water, it is not expected that resuspended material would move onto
the shelf, but rather would remain in the deeper portion of the canyon.
Upwelling processes can affect the dispersal of material suspended in the water column; however,
recent data from EPA surveys indicate that the local upwelling in the Gulf of the Farallones is
weaker than at other sites along the California coast (Ramp et al. 1992). The majority of the
cold saline water on the shelf during summer is advected horizontally into the region from a
strong upwelling center north of Point Reyes. Therefore, it is very unlikely that material,
including dredged material, suspended in the waters over the slope would be transported via
locally upwelled water onto the shelf. Further, water quality modeling results indicate that
significant transport of suspended material to shelf areas from disposal activities at the preferred
or alternative sites would be very unlikely (Section 4.2.1.3).
4.2.1.3 Water Quality
This section discusses dredged material settling behavior and water quality effects.
Dredged Material Settling Behavior
Dredged material disposal may have a short term (several hours to days) impact on the water
column following discharges of solids and solutes from a barge (e.g., Gordon 1974). The
4-12
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greatest proportion of dredged material consists of negatively buoyant solids that sink as a turbid
suspension through the water column to the seabed. Dissolved constituents of dredged material
are entrained in the turbulent water associated with the convective descent. Predictions of the
impacts of the descending plume on the ambient water column depend on the settling velocity
of component particles or particle aggregates, particle concentrations, particle chemistry, water
depth, and the presence and strength of water density stratification (i.e., pycnocline). The fate
of dissolved components depends on their solubility and reactivity with the entrained ambient
water and particles, and mixing properties of the ambient flow field.
The proposed ODMDS is expected to receive dredged sediment of two general types: "mostly
sand" (76% sand, 21% clay, and 3% silt) and "silt-clay" (74% silt, 5% clay, and 21% sand)
(Section 3.1). The settling velocities of the medium sand and coarser material have been
measured in the laboratory. These measurements can be used to estimate the theoretical transit
time in a motionless water column. However, the actual (in situ) settling velocities of individual
particles may vary depending on changes in the density of the water column and water column
turbulence. Sediment dispersion models are most accurate in predicting the transit time and
dredged material footprint of these coarse fractions because of the availability of empirical data
(e.g., Koh and Chang 1973).
The settling behavior of very fine sand and smaller particles is more difficult to estimate because
these fractions rarely consist of discrete particles. Very large aggregates (mud clasts up to a
meter in diameter) may form the bulk of disposed material, particularly when mechanical clam
shell dredges are used to excavate cohesive clay and mud from channels and basins. Smaller
aggregates (up to about 1 mm in size) also dominate the muddy slurry associated with dredged
muds and fine sands. The high surface areas and surface charges associated with fine particles,
particularly clay minerals, promote particle-to-particle aggregation in marine waters. Also, the
presence of biogenic films, which coat the surfaces of small particles, serve to bind fine particles
into low density organic-mineral aggregates. Zooplankton grazing also has been shown to result
in repackaging of suspended particles into rapidly settling fecal pellets (Capuzzo 1983). The
settling velocities of aggregates can be much higher than their component particles. No empirical
4-13
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data, with the exception of the information on zooplankton pellets, exist for accurately estimating
the settling velocities of such aggregates (Komar et al. 1981). Therefore, the behavior of these
aggregates or clumps is the most difficult to predict in dispersion models. The rate of convective
descent of typical estuarine (e.g., from San Francisco Bay) dredged material consisting of large,
cohesive mud clasts has been measured as approximately 1 m/sec (Bokuniewicz et al. 1978); the
exception was the 3 to 5% (by weight) of the material that comprises the fine silt fraction, which
had a sedimentation rate of about 0.7 cm/sec.
Coarse sand (and larger) size fractions and large, cohesive, silt-clay mud clasts settle rapidly to
the bottom and accumulate close to the point of discharge. Slower settling fractions decelerate
as the descending plume experiences dynamic collapse. This is the point of nearly neutral
buoyancy for settling particles, when passive dispersion of this fine fraction takes place. The
depth at which convective descent changes to neutral buoyancy is largely a function of volume
of the barge load (Stoddard et al. 1985). The relationship between buoyancy depth and depths
of pycnoclines and the bottom is important for predicting water column exposures. In deep water
environments, such as the preferred and alternative sites, the buoyancy depth may be much
shallower than the bottom. In this case, the neutrally buoyant plume may intersect a pycnocline,
and slowly settling particles can accumulate and spread laterally along this density interface with
the potential for farfield dispersion by horizontal advection. Therefore, the greatest potential for
long-term, water column impacts and farfield dispersion is associated with slowly settling,
organic-mineral aggregates within the tegion of neutral particle buoyancy and along pycnoclines.
Disposal Plume Modeling
Effects on water quality from dredged material disposal at the preferred and alternative sites were
evaluated using a computer model to determine dispersion and dilution of suspended particles at
varying distances and times following a disposal event (SAIC 1992e). The model calculated the
probability or visitation frequency of particle clouds moving over specific locations in the vicinity
of the sites. This approach was based on models used by Csanady and Churchill (1986) and
Churchill (1987) to assess environmental impacts at ocean disposal sites. The model was adapted
4-14
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for the present application to simulate discrete discharge events and the predicted behavior of
material that settles according to individual particle size classes. The assumptions used in the
model and the model results are described in the following section.
The model assumed that dredged material disposal would occur as discrete events, representing
releases from a barge of 6,000 yd3 of sediments every 12 hours, over a period of one year, for
a total annual volume of 4.38 million yd3. The dredged material was assumed to consist of seven
particle size classes, with class-specific sinking rates. The initial disposal cloud was modeled as
a circular "slab" with a diameter of 100 m and a thickness of 50 m. The "mostly sand" type
material, as modeled, contained a maximum concentration of 5,290 mg/1 of fine sand class
particles. In the "clay-silt" type material, a portion of this fine sand is replaced in the model by
2,500 mg/1 of fine silt particles. These initial particle concentrations would be approximately
1,000 times higher than background or ambient suspended particle concentrations of
approximately 1 to 5 mg/1 (see Section 3.2.3).
The model assumed that the initial cloud separated due to differential sinking and differing rates
of horizontal transport into seven clouds comprising the different size class particles
(Table 4.2-2). Over time and distance from the release point, clouds would spread due to
turbulent diffusion. Under the assumption of constant diffusion, concentrations of particles in
these separate clouds would decrease approximately linearly with time following release. The
model predicted that the average particle concentration within the clouds would decrease to
background concentration (conservatively assumed to be approximately 1 mg/1), or particles
would be deposited on the seabed, within about two days for most particle size classes. During
this time, if the cloud remained in the water column, the cloud diameter would increase by a
factor of 30 or more. Primary exceptions to these time limits (known as the cloud age limit)
were clouds of fine silt (class 6) with high initial concentrations that would remain in the upper
water column for many days. Using small values (1 m2/sec) for the horizontal diffusion
coefficient, it was calculated that clouds of fine silt particles would require about five days to
reach ambient concentrations. However, these calculated times to reach ambient suspended
particle concentrations are sensitive to the assumed value of the horizontal diffusion coefficient.
4-15
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Table 4.2-2.
Particle Size Classes and Sinking Velocities Used in the Sediment
Deposition Model.
Class
1
2
3
4
5
6
7
Name
Coarse Sand
Medium Sand
Fine Sand
Very Fine Sand
Coarse Silt
Clay-Silt
Clay-Silt Clumps
Particle
Diameter
(jun)
1,000
500
250
125
62
31
—
Sinking
Velocity
(m/sec)
0.086
0.041
0.016
0.0052
0.0014
0.0005
0.15
Time
to Sink
1,000m
(hours)
3.2
6.8
17.4
53.4
198.4
556
1.85
Horizontal
Distance
Traveled at
0.1 m/sec (km)
1.15
2.45
6.26
19.22
71.42
200.0
0.67
Percent
by Weight*
1.1
23.9
43.4
7.6
3.3
10.4"
10.3"
* Material Composition Oakland NSC Site.
"Assumes 50% dumping of Clay-Silt Material.
Source: SAIC (1992e).
AK0053.W51
4-16
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Values used for the model are smaller than have been measured directly in the deep ocean
(Ledwell and Watson 1991), but are consistent with the turbulent scales associated with the
characteristic sizes of the clouds. Using diffusion coefficients closer to those measured by
Ledwell and Watson (1991) would reduce the cloud age limit by factors of 5 to 10 times (i.e.,
the time required for particle concentrations to reach background concentrations would be
reduced from five days to 12 to 24 hours.
The model estimated the probability over a one-year period that the water column above
individual "grid" locations on the sea floor would experience the passage of the particle cloud
associated with a discrete discharge event within 48 hours of release. The results are expressed
as a percentage of disposal events contacting a grid location, and are termed the "visitation
frequency." For example, a visitation frequency of 5% for a class 4 (very fine sand) particle
corresponds to a probability of 5 out of every 100 disposal plumes containing very fine sand
particles passing over a specific location. The model also calculated the average depth in the
water column of the cloud as it passed over the grid point (i.e., cloud depth) and the time
required for the cloud to pass over a location (exposure time). Because vertical diffusion is
considered minimal as compared to horizontal diffusion, the modeled cloud maintains a vertical
thickness of 50 m as it passes through the water column (Figure 4.2-1).
In the model, individual particle size clouds separate due to different sinking velocities and would
not be expected to contact each other after disposal. Average cloud depths increase in proportion
to average cloud age and particle concentration due to the constant sinking speed for each class
of particles. Thus, a cloud of coarse sand (class 1) would descend to the bottom within a few
hours and would affect only the water column within a few kilometers of the discharge point.
In contrast, coarse silt particles (class 5) would descend only a few hundred meters within a
period of two days, and would be dispersed greater distances from the discharge point.
Characterizing the dredged material as consisting of discrete particle size classes is appropriate
for the purposes of a practicable model, although it is more likely that actual particle sizes and
sinking speeds would represent a continuum.
4-17
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Cross-Sectional Area of
Affected Hater Column
Figure 4.2-1.
AK0161
Schematic of a Particle Cloud Sinking Through the Water Column.
T=O, T=l, and T=2 correspond to time at the initial disposal and subsequent intervals
during cloud descent through the water column.
Particle concentrations are indicated by relative shades of grey.
Source: SAIC 1992e.
4-18
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4-19
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The calculated visitation frequencies and average suspended particle concentrations associated
with discharges from the preferred and alternative sites are summarized in Table 4.2-3 and plotted
in Figures 4.2-2 through 4.2-4 for Class 6 (clay-silt) particles. (Alternative Sites 3 and 4 are
discussed further in Section 4.4.) This particle class contained the smallest diameter particle
considered, with the corresponding lowest sinking rate, longest water column residency time, and
thus the largest horizontal dispersion or affected area. Larger particles would have relatively
shorter water column residency times and smaller dispersion areas. The fastest falling particles
of the high concentration classes (fine sands and clay-silt clumps) would only spread a few
kilometers from the disposal site, and reach the bottom in 2,000 m water depths within 4 to 24
hours of release. Clouds of particles that settle within the dispersion period (i.e., 48 hours) affect
an area similar to that predicted by the sediment deposition (footprint) model (Section 4.2.1.4)
for a particular size class. The slower settling particles (classes 4 through 6) are the exception
because they do not reach the bottom within 48 hours.
Model results indicated that clouds of coarse to very fine sands and coarse silts (particle classes
1 through 5 and class 7) likely would not be transported across the GOFNMS, CBNMS, or
MBNMS boundaries (i.e., probabilities less than 0.2%). Clay-silt particles (class 6) represent the
only size class of material with a predicted likelihood of being transported across sanctuary
boundaries under the conservative assumptions of high initial concentrations, low dispersion rates
(D = 1 m2/sec), and ambient suspended particle concentrations of 1 mg/1. Based on the model,
plumes of fine grained sediments, representing only a fraction of disposed material, were
estimated to cross the GOFNMS and MBNMS boundaries from only 0.2 to 5% of the disposal
events regardless of which of the sites was used for dredged material disposal. The predicted
particle concentrations within plumes crossing the sanctuary boundaries would be approximately
1 to 2 mg/1 and within the range of presumed background or ambient levels (Figures 4.2-2
through 4.2-4). The calculated average depths of the plumes at the sanctuary boundaries would
range from approximately 60 to 800 m. Using higher dispersion rates (e.g., D = 10 m2/sec) in
the model would result in relatively lower visitation frequencies and particle concentrations in
the vicinity of the sanctuary boundaries (Figure 4.2-5).
4-20
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Table 4.2-3. Model-Predicted Disposal Plume Visitation Frequencies, Mean Depth, and Exposure Times for Simulated
Discharges at the Preferred Alternative (Alternative Site 5) and Alternative Sites 3 and 4.
Area affected corresponds to the area defined by the 1 mg/1 suspended particle concentration contour (i.e., the assumed background
concentration). Visitation frequency represents the probability or percentage of the total number of disposal events in which a cloud of
individual size classes of particles would pass over a particular location on the seafloor. Cloud depth is the average (mean) and standard
deviation (SD) of the depths in the water column of the cloud as it passes over a location. Exposure is the length of time that a position in
the water column would experience higher concentrations of particles relative to background levels. Cloud age is the time required since
disposal for particle concentrations within the cloud to reach Imckground levels or for particles to settle on the bottom. Model-predicted
values based on current data for the period March 15, 1991 through February 15, 1992.
Preferred Alternative (Alternative Site 5)
Particle Size Class
1 : Coarse Sand
2: Medium Sand
3: Fine Sand
4: Very Fine Sand
5: Coarse Silt
6: Clay-Silt
6*: Clay-Silt*
7: Clay-Silt Clumps
Area Affected
(km2)
48
102
336
932
603
3681
1245
23
Visitation Frequency
Mean (%)
6.0
8.2
8.0
4.1
2.1
3.8
5.2
5.2
Maximum (%)
49.2
62.7
64.0
54.1
28.4
37.2
74.4
39.3
Cloud Depth
Mean (m)
2393
2237
1902
725
112
166
54
2335
± SD (m)
370
388
398
113
17
36
5
360
Maximum
Exposure (hrs)
2.6
5.5
13.2
14.0
7.7
43.9
6.7
1.5
Maximum
Cloud Age
(hrs)
10
21
48
48
24
120
24
5
IsJ
*Diffusion coefficient increased from 1 m2/sec to 10 m2/sec.
Source: SAIC (1992e).
AK0052.W51
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Table 4.2-3. Continued.
Alternative Site 3
Particle Size Class
1 : Coarse Sand
2: Medium Sand
3: Fine Sand
4: Very Fine Sand
5: Coarse Silt
6: Clay-Silt
6*: Clay-Silt*
7: Clay-Silt Clumps
Area Affected
(km2)
30
96
414
1227
1082
7855
1717
13
Visitation Frequency
Mean (%)
3.4
3.9
4.2
3.0
1.4
2.2
4.3
2.7
Maximum (%)
21.3
28.6
35.1
22.8
20.3
19.7
62.2
18.7
Cloud Depth
Mean (m)
1237
1326
1315
675
115
168
54
1073
± SD (m)
241
233
265
122
32
28
5
244
Maximum
Exposure (hrs)
1.4
3.3
9.8
16.0
7.0
42.0
6.1
1.0
Maximum
Cloud Age
(hrs)
6
14
41
48
24
120
24
3
Alternative Site 4
Particle Size Class
1 : Coarse Sand
2: Medium Sand
3: Fine Sand
4: Very Fine Sand
5: Coarse Silt
6: Clay-Silt
6*: Clay-Silt*
7: Clay-Silt Clumps
Area Affected
(km2)
32
98
457
1321
1217
7708
1913
13
Visitation Frequency
Mean (%)
3.7
4.7 ,
4.8
3.0
1.3
2.3
3.9
4.3
Maximum (%)
29.6
35.3
35.6
24.9
16.0
19.7
55.4
23.9
Cloud Depth
Mean (m)
1404
1505
1511
694
115
164
55
1378
± SD (m)
284
298
315
128
15
29
5
328
Maximum
Exposure (hrs)
1.6
3.4
10.9
15.4
6.9
42.8
6.1
1.0
Maximum
Cloud Age
(hrs)
6
16
43
48
24
120
24
3
•Diffusion coefficient increased from 1 m2/sec to 10 m2/sec.
Source: SAIC (1992e).
AKOOS2.WS1
-------
-'23.I
Inltlol Concentration : 2500. mg/L
Ar«o Covirid : 3690.64 sqkm
flaoninaximum: 3.8 4 37.2P«rcent
38.0
37.0
37.0
-124.0
-123.1
Figure 4.2-2.
AK0162
p. 10(2
Model-Predicted Visitation Frequencies (red) and Average Particle
Concentrations (green) for Clay-Silt (Class 6) Sediments Discharged
at the Preferred Alternative Site.
Visitation frequencies (in percent) represent the probability of the total number of
disposal events in which a cloud of particles would pass over a location on the
sealfloor. The concentration contour represents the suspended particle concentration
(mg/1) within a cloud as it passes a location. Results were based on current data for
the period March 15,1991 through February 15,1992, and used a diffusion
coefficient of D=l m2/sec.
Source: SAIC 1992e.
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Figure 4.2-2. Continued.
AK0162
p. 2 of 2 4-24
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Initial Conosntrollo
Aria Coversd : 7854.
Mean & Maximum : 2.
37.0
-124.0
Figure 4.2-3. Model-Predicted Visitation Frequencies (red) and Average Particle
Concentrations (green) for Clay-Silt (Class 6) Sediments Discharged
at Alternative Site 3.
Visitation frequencies (in percent) represent the probability of the total number of
disposal events in which a cloud of particles would pass over a location on the seafloor.
The concentration contour represents the suspended particle concentration (mg/1) within
a cloud as it passes a location. Results were based on current data for the period March 15,
1991 through February 15,1992 and used a diffusion coefficient of D=lm2/sec.
Source: SAIC 1992e.
AK0163 . 0<-
p. 1 0(2 4-25
37.0
-182.7
-------
This page intentionally left blank.
Figure 4.2-3. Continued.
AK0163 A _ _
p. 2 of 2 4-26
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Jnltlsl ConotnlrollanO
ovtrvd i 77rfŁ»57 c
t1o«llPU« 1 Y.3
37.0
-134.0
Figure 4.2-4. Model-Predicted Visitation Frequencies (red) and Average Particle
Concentrations (green) for Clay-Silt (Class 6) Sediments Discharged
at Alternative Site 4.
Visitation frequencies (in percent) represent the probability of the total number of disposal
events in which a cloud of particles would pass over a location on the seafloor. The
concentration contour represents the suspended particle concentration (mg/1) within a
cloud as it passes a location. Results were based on current data for the period March 15,
1991 through February 15,1992 and used on diffusion coefficient of D=lm2/sec.
Source: SAIC 1992e.
AK0164 1.77
p.1ot2 * *'
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Figure 4.2-4. Continued.
AK0164 « ~r.
P. 2 of 2 4-28
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Initial ConointroUon : 2500. mg/L
Aria Cavired : 1244.93 lakm
Mian & floximum : 5.2 4 74.4 Percent
37.0
37.0
-124.0
-123.1
Figure 4.2-5.
AK0165
p. 1o(2
Model-Predicted Visitation Frequencies (red) and Average Particle
Concentrations (green) for Clay-Silt (Class 6) Sediments Discharged
at the Preferred Alternative Site Using a Diffusion Coefficient of
D=10m2/sec.
Visitation frequencies (in percent) represent the probability of the total number of
disposal events in which a cloud of particles would pass over a location on the seafloor.
The concentration contour represents the suspended particle concentration (mg/1) within
a cloud as it passes a location. Results were based on current data for the period
March 15,1991 through February 15,1992.
Source: SAIC 1992e.
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Figure 4.2-5. Continued.
AK0165
p. 2 of 2 4-30
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The duration of turbid plumes near the discharge site would vary with the frequency and location
of disposal events. Although the model assumed that disposal would occur every 12 hours, the
actual frequency of disposal events at an ODMDS is unknown but is likely to be less frequent
than assumed by the model. As a result, impacts on water quality associated with dredged
material plumes are expected to be transitory when site use is intermittent. Furthermore, disposal
likely will take place at various locations within the approved disposal site and, consequently,
the plumes would not originate from the same location. The direction of transport for individual
plumes also would vary depending on the prevailing current patterns.
Specific results from the water quality model of discharges at the preferred alternative site
suggested that disposal plumes corresponding to individual particle size classes would affect areas
from 23 to 3,681 km2, with mean visitation frequencies from 2.1 to 8.2% (Table 4.2-3). Higher
visitation frequencies calculated for the preferred alternative site, as compared to Alternative Sites
3 and 4 (see Section 4.4.1.3), are due to the greater water depth and longer descent times, which
would allow the clouds to increase in size and affect a larger percent of the region immediately
adjacent to the preferred alternative site. For individual particle classes, mean cloud depths
ranged from 54 to 2,393 m. Maximum exposure times, defined as the time during which
background concentrations of suspended particles are exceeded at a particular point, ranged from
approximately 1.5 to 44 hours. Use of the preferred alternative site would result in
concentrations from 1 to 2 mg/1 of suspended particles at the boundaries of the GOFNMS and
MBNMS for 0.2 to 1% of the disposal events, (i.e., 2 to 10 occurrences per 1,000 discharge
events, Figure 4.2-2). These concentrations are within the presumed range of normal ambient
values for suspended particles and would not be expected to result in measurably elevated
concentrations within the sanctuaries. Concentrations at the CBNMS boundary would not be
expected to be elevated above background concentrations at any time.
Water Quality Effects
Potential impacts on water quality from dredged material disposal are expected to be transient
at the preferred alternative site, therefore representing Class HI impacts. These changes
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correspond to localized increases in turbidity, reductions in light transmittance, and increases in
dissolved and particulate concentrations of trace chemical constituents contained in the dredged
material. The following is a discussion of generic effects; expected effects for the preferred
alternative are summarized below.
Chemically reduced inorganic compounds associated with particles sinking through the upper
water column (generally above a depth of 400 m) may be oxidized, causing a transient increase
in the chemical oxygen demand. Oxidation of labile organic material consequently may reduce
dissolved oxygen concentrations in the water. However, because the upper water column in the
study region is well oxygenated, this effect may be more pronounced at depths corresponding to
the oxygen minimum zone (OMZ) where dissolved oxygen concentrations are naturally low (i.e.,
less than 2.8 mg/1; Figure 3.2-7).
Similarly, depending on the chemical composition of the dredged material, elevated
concentrations of sinking particles may cause changes in the concentrations of trace chemical
constituents in the water column. Because the bulk chemical composition of the dredged material
is not known, assessments of the contributions of suspended particles to changes in water quality
at the preferred and alternative sites, and subsequent comparisons to marine water quality criteria,
presently are not possible. However, these chemical concentrations are expected to be low
because dredged material must be tested and the results meet established criteria in order to be
acceptable for disposal (see Section 4.6). Evaluations of changes in water quality due to a
specific disposal event will be made during the permitting process for individual dredging
projects.
Dredged material disposed at an ocean site also can introduce dissolved solutes or gases, such
as hydrogen sulfide, methane, manganese, iron, ammonia, and phosphorus, that occur naturally
in estuarine sediments such as San Francisco Bay. These may be introduced in solution or
subsequently released into ambient waters by desorption from particles and/or release of trapped
interstitial gas from the break-up of falling cohesive mud clasts. Material deposited on the
bottom represents a second source of dissolved compounds (Salomons et al. 1987). Once solid
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particles reach the seafloor, changes in pH and redox potential (Eh), and benthic organism and
microbial activity, can redissolve metals and organic compounds. Remobilized, dissolved
compounds can accumulate in sediment porewaters or in water overlying deposited material or
sediments (Forstner and Wittman 1983; Bryan 1984; Graybeal and Heath 1984; Landner 1986;
Salomons et al. 1987).
The chemical fate of dissolved contaminants in seawater will be affected by a variety of physical,
chemical, and biological processes. These factors include: (1) circulation and mixing processes;
(2) the presence of organic matter, clays, iron and manganese oxides and hydroxides; (3) salinity;
(4) biological uptake processes; (5) chemical conditions (Eh, pH) in the sedimentary and water
environment; and (6) the properties of the compound itself. Water circulation may be the most
important factor affecting dispersal of contaminants in the oceans (Bryan 1984). Dissolved
constituents also are diluted as the discharged material settles through a deep water column. In
the deep ocean, near-bottom currents are capable of dispersing dissolved materials that have
diffused out of deposited sediments. Conversely, local topographic depressions, such as
submarine valleys or troughs, have the potential to trap finer-grained sediments which often
contain relatively higher concentrations of trace chemical constituents.
Organic matter, clays, and iron oxides all have the ability to adsorb dissolved organic compounds,
metals, and salts due to the ion-adsorptive properties (Lee 1975; Stumm et al. 1976; Hem 1977;
Kerndorf and Schnitzer 1980; Leckie etal 1980; Davis and Gloor 1981; Tipping 1981; Forstner
and Wittman 1983; Hunter 1983; Balistrieri and Murray 1986; Landner 1986). Present evidence
suggests that cycling and residence times of dissolved and paniculate metals in the oceans are
controlled by a combination of biological scavenging and uptake by surface-reactive particles
(Fisher et al. 1991). Bio-concentration of metals through uptake by zooplankton may result in
the production of metal-rich zooplankton fecal pellets. These particles serve as an important
vehicle for the rapid removal and sedimentation of contaminants to the seafloor (Capuzzo 1983),
and affect the residence times of elements in the ocean (Fowler 1977; Cherry et al. 1978; Fisher
etal. 1991).
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Adsorption and scavenging of metals by organic particles or organic coatings on particles is
another important process that removes metals from the water column (Brewer and Hao 1979;
Balistrieri et al. 1981; Forstner and Salomons 1982; Balistrieri and Murray 1983, 1984; Hunter
1983; Bryan 1984; Collier and Edmond 1984; Honeyman et al. 1988). Particle concentrations
in the water column may be the most important variable affecting metal removal (Capuzzo 1983;
Honeyman et al 1988). Organic matter appears to have greater ability to form complexes with
metals than with inorganic minerals (Balistrieri et al. 1981). Desorption of metals may be driven
by interactions with paniculate or dissolved ligands (or both) in seawater (Erel and Morgan
1991). Thus, the fate of metal contaminants, even in the dissolved phase, is strongly affected by
the number and kinds of particles that are present in the descending or dispersing plume and in
the ambient water column.
Once particles have reached the sea floor, reducing conditions may develop again beneath the
oxidized surface sediment layer, particularly if concentrations of labile organic carbon are greater
than about 1%. Thus, remobilization of metals from particles could occur in both the water
column (OMZ) and in the sediment column, resulting in a release of dissolved metals to the
overlying water or to porewater.
The mobility of certain metals is strongly affected by pH and the Eh of the environment. Metals
which become soluble under reducing conditions include iron, manganese, and mercury (Bothner
et al. 1980), whereas oxidizing conditions favor the release of cadmium, nickel, lead, and zinc
(Bryan 1984). Dissolution of certain metals under anoxic conditions is balanced by their
precipitation as metal sulfides. The dissolution of iron or manganese oxides releases other
metals, such as zinc, copper, cobalt, nickel, and lead, and organic compounds which were
adsorbed to these compounds (Elderfield and Hepworth 1975; Bryan 1984).
Biological activity, including bioturbation and microbial activities, in sediments also can
remobilize contaminants in deep-sea surface sediments (Graybeal and Heath 1984). Microbial
decomposition of organic matter, including organic compounds, can transform compounds from
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one form to another, potentially affecting their toxicity, mobility, and release to the water column
(Metcalf 1977; Colwell and Saylor 1978; Bryan 1984).
Effects to water quality from dredged material disposal at the preferred alternative site are
considered Class HI potential impacts because plumes are expected to disperse within 48 hours
of discharge, no build-up or accumulation of particles within the water column is expected, and
changes to water quality parameters (e.g., turbidity, light transmittance, dissolved oxygen
concentrations) are expected to be transient and localized within the discharge plume. Disposal
operations should have insignificant effects on concentrations of contaminants in the water
column, given that only dredged material of suitable quality will be permitted for disposal.
4.2.1.4 Geology and Sediment Characteristics
Dredged material disposal operations at the preferred alternative site are not expected to result
in any significant changes in regional bottom topography or sediment transport processes,
although minor accumulations of sediments to depths of a few to several centimeters could occur
within the sites (discussed below). In the vicinity of the alternative sites, where depths are
greater than 1,600 m and slope angles are small, mounding of bottom sediments or slight changes
in sediment stability conditions are not a primary concern (Class in impact). Accumulation of
dredged material, and associated changes in the sediment characteristics may cause impacts to
benthic-dwelling organisms (Sections 4.2.2.2 and 4.2.2.3).
Particle Deposition (Footprint) Model
The spatial extent of effects at the preferred and alternative sites were evaluated using a sediment
deposition (footprint) model to predict the horizontal transport of theoretical dredged material
particles and cumulative deposit thicknesses on the seafloor (SAIC 1992e). The assumptions and
the results of the model predictions are summarized below.
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The deposition of dredged material was assumed to result from a continuous release from the
surface to increase the statistical confidence for modeling long-term deposition. This was
accomplished by simulating the release of approximately 16,000 discrete particles for each size
class over a one-year period. The source material was divided into independent particle size
classes which could be tracked as the material sinks through the water column. The locations
of particles for each size class were estimated using the model which incorporated all influences
on particle movement. These influences included tidal and non-tidal currents sampled during a
one-year period (March 1991 through February 1992). The model advected (transported)
particles horizontally according to estimates of the local current velocity at each time step. One-
year current records from measurements described in Section 3.2.2 were used to calculate the
velocities. Linear interpolation between velocity positions on the current meter moorings was
used to estimate current velocities at specific locations and depths; this accounted for vertical and
horizontal spatial variability of the current field experienced by a sinking particle. The vertical
distance traveled was determined by the sinking velocity.
Standard particle sizes and their associated sinking speeds are listed in Table 4.2-2. The table
also lists the calculated time to sink to 1,000 m depth for seven size classes of particles or
clumps under horizontal current speeds of 10 cm/sec. Water depths at the preferred and
alternative sites vary from approximately 1,400 to 3,000 m, and maximum current speeds vary
from 30 cm/sec on the slope to 20 cm/sec in the layers below 1,000 m (Section 3.2). As noted
in the table, the larger and heavier particles would be displaced only a few kilometers, whereas
very fine sands and fine and coarse silts would be transported tens of kilometers before reaching
the bottom.
The particle size composition of the dredged material planned for disposal at the ODMDS
presently is unknown because of the wide variety of sediment types occurring at potential
dredging sites within the Bay. As noted for the water quality model (Section 4.2.1.3), two cases
were assumed for the average composition of material discharged at each alternative site: a silt-
clay type and a mostly sand type. It is likely that the majority of the material to be disposed at
an ODMDS would be dredged using a clam shell dredge. This type of dredging equipment does
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not add much water to the dredged material, as opposed to a suction-type dredge. Therefore, the
dredged material likely would retain the clumped character of the original Bay muds. The extent
to which cohesive materials become fluidized by the dredging operations and transit to the
disposal site presently is unknown. Therefore, an assumption of 50% clumping of the clay-silt
material was made for the purposes of the model. Smaller clumping factors (i.e., less than 50%)
would result in smaller maximum deposit thicknesses, but little or no change in the area covered
with deposits thicker than 1 mm. This is because fine silt material would be dispersed so widely
that effects to the predicted deposit thickness would be negligible. In contrast, sandy materials
contained in the dredged sediments are not cohesive and would act as individual particles
following disposal from a barge. Therefore, these particles' behavior would not be expected to
change as factors influencing clumping were varied.
The measurements made by the EPA study (Section 3.2.2.2) provided the first long-term, deep-
water current data for this region. Because few current measurements have been made over the
continental slope off San Francisco, there was no definitive basis for determining the
representativeness of these current measurements relative to long term climatology or interannual
variability (see Section 3.2.2.1). Modeling was performed using segments of the data that, could
represent the seasonal and inter-annual variability of the region.
The distinct changes in the current characteristics between the first and second portions of the
study prompted the modeling of deposition over a one-year period as well as two six month
periods. The first time period coincided with the complete period of the current measurements
(March 15, 1991 through February 15, 1992). The second and third periods corresponded to the
first and second six-month segments of these current records. The first six-month period was
characterized by a strong poleward flow, whereas, the second six-month period was characterized
by weak, intermittent flows followed by episodic poleward events. The mean and maximum
deposition decreased and the areas of deposition increased with increasing current speeds.
The model simulations assumed that the momentum from the initial release dissipated at a depth
of 20 m, and particles acted independently at depths below 20 m. Other simulations were
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performed which varied this depth between 20 and 250 m for a continuous discharge over a one
year period in 1,000 m of water. The results did not change significantly despite this depth
variation. The model also assumed that discharges did not occur at the same location each day.
Instead, the discharge positions were randomized on a daily basis over a region defined by a
watch circle having a diameter of 2 km and centered in the southern to central portion of the
western boundary for each site. This area corresponds to the proposed site of the discharge area
for the ODMDS. However, should the size of this area be changed in the final designation of
the site, this model's assumption would represent a conservative estimate of predicted impacts.
The bathymetric data used in the model simulations were from NOAA's EEZ side scan surveys;
these data provided the highest resolution grid available for the study region and resolved
bathymetric features to an accuracy of a few meters.
Table 4.2-4 presents the mean and maximum cumulative deposit thicknesses for the two material
types, accounting for all particle size classes. For all alternative sites, the silt-clay material would
produce the greatest thickness near the disposal site because of the contribution from
rapidly-sinking clumps. In contrast, the maximum thickness of sand is only 60 to 70 mm. The
table also lists the areas covered by deposits with thicknesses exceeding 1 mm at the end of the
period. The quantities of material that would be advected or lost outside of the boundaries of
the model also were calculated. The total percent loss consisted entirely of coarse and fine silts.
This material would be deposited far from the disposal site, with respective accumulation
thicknesses of less than 1 mm for the modeled discharge volumes (6 million yd3).
Comparisons between the two six-month periods generally indicated higher amounts of deposition
and less area covered for the less energetic August to February period than for the more energetic
spring period. The 12-month period showed deposition amounts and areas that were intermediate
between the two six-month periods.
The simulated depositional footprints for the mostly sand and silt-clay materials at the preferred
and alternative sites are shown in Figures 4.2-6 and 4.2-7. The contour lines correspond to
deposit thicknesses of 1 mm, 10 mm, and 100 mm. The predicted bottom deposits were
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Table 4.2-4.
Model-Predicted Deposit Thicknesses, Areal Coverage, and Material
Losses Due to Transport Outside of the Model Boundaries
Based on current data for the period March 15, 1991 through February 15, 1992.
Alternative
Site
3
4
5*
Material
Type1
C-S
M-S
C-S
M-S
C-S
M-S
Mean Deposit
Thickness
(mm)2
7.94
4.46
9.78
5.25
9.75
5.87
Maximum Deposit
Thickness
(mrn)
727.2
62.0
788.3
69.4
493.2
65.5
Percent
Loss
19.3
11.4
21.4
12.7
27.1
16.2
Area
Covered
(km2)3
362.8
624.4
283.8
500.1
278.6
449.1
1C-S = Clay-Silt Mixture, M-S = Mostly Sand Mixture.
2For deposits with thicknesses greater than 1 mm.
3Area covered by deposits with thicknesses greater than 1 mm.
'Preferred Alternative Site.
Source: SAIC (1992e).
AK0056.W51
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-123.7
37.9
37.'
GOFNMS
-123.0
37.9
37.1
-123.7
-123.0
Figure 4.2-6.
AK0167
p. KK2
Model-Predicted Bottom Deposit Thicknesses (in mm) From Discharges
of Six Million yd3 of Clay-Silt Type Material Over a One-Year Period at
the Preferred Alternative Site (red), Alternative Site 3 (green), and
Alternative Site 4 (blue).
The solid black lines near the respective 2 km watch circles (i.e., discharge point) correspond
to deposit thicknesses of 100 mm, 200 mm, etc. Results are based on current data for the
period March 15,1991 through February 15,1992 and used a diffusion coefficient of
D=l m2/sec.
Source: SAIC 1992e.
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Figure 4.2-6. Continued.
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P. 2 oi 2 4_42
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37.1
-133.7
37. I
-123.0
Figure 4.2-7.
AK01G8
p. 1o(2
Model-Predicted Bottom Deposit Thicknesses (in mm) From Discharges
of Six Million yd3 of Mostly Sand Type Material Over a One-Year Period
at the Preferred Alternative Site (red), Alternative Site 3 (green), and
Alternative Site 4 (blue).
Results are based on current data for the period March 15,1991 through February 15,1992 and
used a diffusion coefficient of D= Im2/sec.
Source: SAIC 1992e.
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Figure 4.2-7. Continued.
AK016S
p. 2 of 2 4-44
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discontinuous in some areas because of the effects of topographic irregularities on the deposition
patterns. Significant impacts to bottom-dwelling organisms from smothering would be most
likely in areas where the thickness of recently-deposited material exceeded 100 mm (10 cm)
(Rhoads and Germane 1990; see Section 4.2.2.2). The 1 mm deposit represents the minimum
thickness that might be measured practically using existing technologies, and does not correspond
to any known or predicted adverse impact to the benthic environment. The 10 mm deposit
represents an intermediate reference thickness that was used as the basis for defining the size and
shape of the preferred and alternative sites (Section 2.2). Modeling the 1 mm and 10 mm deposit
thicknesses was intentionally conservative for predicting potential effects, but was considered
useful for possible monitoring purposes to determine where measurable amounts of dredged
material would be deposited. These deposit thicknesses are much lower than 100 mm thicknesses
where significant impacts to benthic organisms would be expected. Also, impacts associated with
100 mm thicknesses would result from instantaneous deposition, whereas, the modeled deposits
were accumulated over a period of one year.
The deposition model predicted that disposal of six million yd3 per year of clay-silt and mostly
sand type material at the preferred alternative site would result in bottom deposits with
thicknesses greater than 1 mm covering areas of approximately 280 and 450 km2, respectively.
The maximum deposit thicknesses for these material types would be approximately 490 and 66
mm, respectively, and the mean deposit thicknesses over these areas would be 9.8 and 5.9 mm,
respectively. The model-predicted bottom deposits with thicknesses greater than or equal to
100 mm would cover an area of 7.29 km2 based on discharges of 6 million yd3 of silt-clay
materials over a one-year period.
The 1 mm and 10 mm deposit thickness contours for the clay-silt type material for all alternative
sites do not extend into any of the National Marine Sanctuaries. The 1 mm deposit thickness for
the mostly sand type material discharged at Alternative Site 5 extends into the GOFNMS,
whereas, the bottom deposits corresponding to Alternative Sites 3 and 4 do not cross the
sanctuary boundaries.
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The model assumed that deposition of material is cumulative. It does not account for losses due
to sediment transport processes such as bottom current resuspension and transport and/or mass
movement, which would reduce the estimated thickness of the deposit but also increase the
bottom area affected. The preferred alternative site is located within a depositional zone
characterized by low kinetic energy and fine grain size sediments with a relatively high organic
content (Section 3.2). It is expected that the depositional characteristics of the site will minimize
the bottom current-induced dispersion of deposited dredged material. Use of the site over a
period of 50 years would increase the predicted deposit thicknesses as well as the areas covered
by deposits with thicknesses exceeding 1 mm. However, over time physical processes (e.g., mass
wasting) and biological processes (e.g., bioturbation) may transport and mix the dredged material
with existing and recently-deposited sediments, thus, reducing differences between the physical
characteristics of the dredged material and those of existing sediments and reducing potential
impacts.
Because the grain size and chemical characteristics of sediments potentially discharged at the
ODMDS are unknown, the specific effects of dredged material disposal on long-term changes to
the properties of the bottom sediments cannot be evaluated or quantified accurately. Sediments
must be evaluated using testing procedures for dredged material described in EPA/COE (1991)
to ensure that chemical constituents are not present at concentrations that would be toxic to, or
bioaccumulated by, marine organisms. Only material deemed acceptable under these protocols
would be approved for disposal at an ODMDS.
Effects from dredged material disposal at Alternative Site 5 on sediment grain size are expected
to represent a Class I impact. This impact also would be localized and would persist for the
duration of site use assuming a continuous disposal schedule. Effects to sediment chemical
quality are considered a Class in impact.
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4.2.2 Effects on Biological Environment
The following sections discuss the potential consequences of the proposed action on the
biological environments associated with the preferred alternative site.
4.2.2.1 Plankton
Any significant water column impacts to the pelagic ecosystem would most likely involve those
planktonic organisms that come in contact with slower-settling particles, such as silts, in regions
of neutral buoyancy, such as the pycnocline. The impact of suspended particles from dredged
material disposal on planktonic organisms is expected to be minimal for the rapidly settling size
fractions, including sand and clay-silt aggregates, that reach the bottom within a few minutes to
hours (see Section 4.2.1.4).
Some effects of water column turbidity on open ocean planktonic species have been addressed
experimentally by a study designed to predict the impact of surface discharges of deep-sea muds
simulating a manganese mining operation (Hirota 1985). These results indicated increased
mortality and lower recruitment rates in 12 species of epipelagic copepods and one species of
mysid exposed in the laboratory. However, mortality of copepods collected in the field from a
simulated plume showed only slightly higher mortality relative to reference populations collected
from outside the plume (Hirota 1985).
A laboratory study of exposure of the copepod Calanus helgolandicus to fine-grained red bauxite
muds showed lower survival, growth rates, and body weight at concentrations above 6 mg/1
(Paffenhofer 1972). This same type of mud resulted in decreased egg hatching success and
lowered survival of larval Atlantic herring (Clupea harengus) and adversely affected embryo
development and larval feeding at concentrations in the range of 600 to 7,000 mg/1
(Rosenthal 1971).
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The results from these studies cannot be extrapolated directly to dredged material disposal
because most of the adverse biological effects were related to organisms ingesting mineral-rich
and nutrient-poor deep-sea ooze or bauxite "red mud". These nutrient-poor suspensions resulted
in starvation of the exposed species. Because dredged material plumes will typically consist of
relatively organic-rich muds, and will be transient in nature, similar impacts to planktonic
organisms are unlikely.
Potential effects of disposal-related turbidity on planktonic organisms are difficult to assess due
to the transient nature of the dredged material plume and the free-floating or mobile
characteristics of the organisms. Turbid plumes associated with dredged material disposal can
temporarily attenuate light penetration into the water column, thereby reducing primary
production by phytoplankton. Measurements of primary production in a disposal plume showed
50% reduction in productivity compared to that of ambient phytoplankton populations (Chan and
Anderson 1985). However, this effect lasted only a few hours until the plume dissipated.
Additional factors which complicate these assessments are seasonal and annual variations in
plankton productivity, standing stock, and species composition (Section 3.3.1).
Since the duration of potential plume exposure is short and of limited spacial extent, the overall
effect of disposal on plankton communities at the preferred alternative site is expected to be
insignificant (Class III; Table 4.1-1). This conclusion also is based on significant, natural
variation in plankton communities throughout the general study region. The highest plankton
abundences are inshore of the preferred and alternative sites and there are no distinguishable
differences between the sites.
4.2.2.2 Infauna
Impacts of Burial
As dredged material accumulates on the seafloor, benthic organisms in the area of initial
deposition may be impacted. However, information on the response of deep-water organisms to
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burial or smothering is limited. The ability of buried infauna (or epifauna) to reestablish normal
depths and orientations within bottom sediments is an adaptation for surviving burial from natural
events such as storm-related changes in sedimentation or slumping. In deep water, particularly
on the continental slope and rise, turbidity currents, submarine slumps, and debris flows can be
major natural causes of burial (Hollister et al. 1984). The frequency of disturbance and depth
of burial are also critical for determining the response of infauna to burial. Frequencies of
disturbance that are less than one year tend to keep the colonizing benthos in an early
successional stage while burial frequencies much greater than one year allow colonization of
higher order successional species with longer mean life-spans and more conservative reproductive
strategies (e.g., Rhoads et al 1978).
Impacts to bottom-dwelling organisms from burial by either natural processes or dredged material
disposal can vary from negligible to localized mortality, depending on the rate of accumulation,
burial depth, textural and mass properties of the deposited sediment, burial time, water
temperature, and the species experiencing burial. This type of impact has been quantified for
several species in estuarine environments. For example, Kranz (1974) determined the depth of
burial that caused mortality of several bivalve species. The critical burial depth for epifaunal
suspension feeders was less than 5 cm, while infaunal deposit-feeders could survive and burrow
through as much as 50 cm of overburden. In situ burial experiments by Nichols et al. (1978)
indicated that overburden thicknesses of 5 to 10 cm did not cause significant mortality to
"mud-dwelling" invertebrates as most of these motile infauna could initiate "escape" responses
by burrowing upward, while organisms covered with overburdens of 30 cm could not initiate
escape responses. Similar results for estuarine organisms were documented in a laboratory study
by Maurer et al. (1978), who also noted critical overburden thicknesses of 5 to 10 cm. The
critical burial depth for estuarine infauna therefore appears to range from 5 to 30 cm. The
response of a species to a specific overburden thickness can be estimated from how frequently
a species population experiences natural sediment burial. For example, species living on rippled
bottoms or sediments subjected to resuspension are better able to withstand burial by relatively
thick sediment layers than species living in low kinetic energy, low sedimentation rate areas.
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Generalizations about critical burial depths based on shallow water data noted above are directly
applicable to Study Area 2 and perhaps the shallower part of Study Area 3. However, care must
be exercised in extrapolating these observations to deep water as comparable data on critical
burial depths for deep-sea benthos have not been fully investigated. The present information
comes from observations of the burial of benthos by "accidental" sedimentation events. Jumars
(1977) reported an accidental burial of benthos in the San Diego Trough (1,200 m depth) by a
small avalanche of sediment (2 to 10 cm thick) produced by a submersible. The next day, the
site was revisited and the submersible took cores through the new sediment layer. Organisms
were beginning to migrate upward through layers 1 cm thick, while deeper burial resulted in
increased mortality. The polychaete Prionospio spp. was noted to be an important casualty in
this experiment, suggesting that surface deposit feeders might be most affected by burial (Jumars
1977). Prionospio delta is present in water depths of > 2,000 m in the Farallones region. These
observations suggest that deposition of shallow layers of sediment at these depths might allow
deep water species to recover from burial, but that disposal layers substantially deeper than 10
cm might cause high local mortality. Support for this inference is presented from Study Area
5, sampled in 1990 and 1991 (SAIC 1991; SAIC 1992c). In 1990, high densities of infauna were
recorded at Station F-17, while in 1991 densities near Station F-17(B-5) were lower by a factor
of seven (see Section 3.3.2.1). Bottom photography showed a "hummocky" surface typical of
sedimentation deposits. One explanation for the change in density between 1990 and 1991 is
partial mortality related to an intervening depositional (burial) event.
Rapid burial of a benthic community by 30 to 100 cm thick, natural turbidity flows in the
Cascadia Channel (2,900 to 3,000 m depth) off the Oregon and Washington coast resulted in a
"no escape" response of the buried species. An inference of total mortality was based on the
absence of escape burrows across the contact zone between the buried and basal layers of the
overlying sediments (Griggs et al 1969). There are no direct studies on the ability of slope-
dwelling infauna to escape from thinner deposits of sediments. However, based on the
considerable abilities of many species to burrow through and modify natural sediments (Hecker
1982), it is likely that many slope infaunal species would have the ability to survive periodic
burial by submarine slumping or moderate amounts of dredged material.
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In summary, available information on shallow-water infaunal invertebrates indicates that the rapid
accumulation of sediments (either natural sediments or dredged material) in thicknesses exceeding
approximately 5 to 30 cm can result in significant mortality of the buried species. Sessile or
otherwise immobile species are the most sensitive to burial while mobile deposit-feeding infauna
have the greatest ability to escape upward through newly deposited sediments.
Colonization after Deposition
Colonization by infaunal organisms of deposited dredged material has been well documented in
shallow water environments, but equivalent studies at deeper depths are lacking. In most cases,
the colonization process in shallow water begins within a few days following cessation of
discharges (Germane and Rhoads 1984; Scott et al. 1987). The mode of colonization is sensitive
to the thickness of the deposit. For thin overburden layers (less than or equal to 10 cm), buried
adults have an upward escape response, with selective survival based on the ability of different
species to reestablish their natural vertical depth positions within the new sediments. When
dredged material accumulates in a thick mound, only the thin, distal edges of the deposit may
be colonized by this means. The thicker part of the deposit primarily is colonized through larval
recruitment or immigration of organisms from adjacent, undisturbed areas.
In shallow water (less than 50 m depth), colonization by adults (reburrowing) and larval
recruitment normally is very rapid, taking only a few days to weeks to establish a low diversity
but abundant pioneering community. Rapid colonization is attributed to the presence of
competition-free space and the availability of detrital organic food that commonly is in greater
concentration in dredged material than on the ambient seafloor. In addition, the diffusion of
sedimentary sulfides from dredged material into the water column may serve as a larval
settlement cue and as a nutritional factor for opportunistic species such as Capitella (Cuomo
1985; Tsutsumi 1992).
In shallow water disposal site studies, three phases of macrofaunal recolonization have been
described (Rhoads and Germano 1982, 1986, 1990; Scott et al. 1987). This successional
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paradigm is based on "...the predictable appearance of macrobenthic invertebrates belonging to
specific functional types following a benthic disturbance" (Rhoads and Boyer 1982). The first
organisms (Stage I) to colonize a disposal site by larval recruitment are usually small
opportunistic polychaetes, such as Spionidae and Captellidae. Species within these families are
commonly associated with frequently disturbed and/or organically enriched areas (Pearson and
Rosenberg 1978). The worms form dense tube mats and feed at, or near, the sediment surface.
Within one or two years, these dense polychaete assemblages may be replaced by dense
aggregations of tubiculous amphipods and tellinid bivalves (Stage II). Densities of pioneering
species on dredged material often are significantly higher than densities on the ambient bottom.
Disposal sites can exceed the secondary productivity measured on the natural seafloor by a factor
of six fold or more (Rhoads et al. 1978). The degree of enhancement of secondary productivity
is proportional to the amount of labile organic matter in the dredged material because organic
detritus serves as food for many resident benthos. This high secondary productivity may account
for intensive foraging by mobile predators observed at many disposal sites (Becker and Chew
1983; SAIC 1989a).
Larval recruitment and establishment of Stage in species on a disposal site requires several years
because these organisms tend to have more conservative reproductive strategies, slower
population and developmental growth rates, and longer mean life spans (Pearson and Rosenberg
1978; Rhoads et al. 1978; Hecker 1982). Stage HI species are "head-down" deposit feeders and
are commonly encountered as part of the equilibrium community on ambient mud bottoms
adjacent to disposal sites. Stage in species typically consist of deep burrowing polychaetes (e.g.
Maldanidae, Pectinariidae), caudate holothurians, infaunal ophiuroids, or burrowing urchins.
Deep burrowing is accompanied by vertical bioturbation of both particles and pore-water fluids
to depths of 10 to 20 cm or more. Bioturbation modifies sediment chemistry through oxidation
of the sediment column and advective exchange of sulphate, ammonia, or nitrate across the
sediment water interface (Aller 1982; Rice and Rhoads 1989). Similarly, bioturbation can change
the chemical properties of dredged material and its associated constituents (Rhoads et al. 1977).
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A series of biological, physical, and chemical changes occur over a period of several months to
years after disposal operations cease. The changes include gravitational compaction and
biological modifications as well as the reshaping of the deposit in relation to current-mound
interactions. Small-scale boundary roughness of cohesive materials is reduced over time as
surficial bioturbation and surface current scour reduce elevations and fill in depressions.
Diversion of flow over a mound can result in a local change in mound texture as fine-grained
sediments are eroded, leaving a coarser surface layer. Long-term bioturbation by Stage III
species can result in a progressive increase in fluidization and oxidation of the surface of a
dredged material deposit. Furthermore, bioturbation can cause pelletization and repackaging of
organic-mineral aggregates which decreases the overall cohesiveness of fine-grained sediments
(Rhoads 1991) and often results in the surface becoming physically destabilized (Rhoads and
Boyer 1982). Such biogenic processes can contribute to destabilization of the bottom over the
long term, especially on slope environments (Hecker 1982).
The successional changes described above for shallow water disposal sites applies only to sites
that experience "normal" succession. Normal succession involves rapid initial colonization
progressing to Stage in within one to two years. Such a progression can be retarded or stopped
if disposal operations are continuous or frequent, if the disposed material experiences erosion and
dispersal, or if the disposal area is seasonally or permanently affected by low dissolved oxygen.
The relationship between near bottom dissolved oxygen and the successional model indicates that
mobile epifauna or demersal species avoid regions with dissolved oxygen concentrations below
approximately 3 mg/1. Dissolved oxygen concentrations below about 1.4 mg/1 appear to prevent
successful colonization of Stage III taxa (Tyson and Pearson 1991). The ecological and
physiological effects of low oxygen conditions can be compounded by hydrogen sulfide and/or
methane gas associated with organically enriched hypoxic habitats. These compounds may
further stress benthic species. Additionally, if pollutants are present, the ability of an oxygen-
stressed organism to survive exposure may be significantly reduced. These synergistic effects
are poorly known. The shallow portions of Study Areas 3 and 4 are within or near the OMZ
(Section 3.2), but the preferred and alternative disposal sites are located in waters deeper than
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the OMZ. Disposal at any of the sites is unlikely to result in reduced colonization due to low
oxygen tensions.
The successional patterns described above for shallow-water disposal sites have been compared
to results from studies at deeper water dredged material disposal sites off Los Angeles (LA-2)
in 110 to 320 m of water (SAIC 1990a) and off San Diego, CA (LA-5) in 100 to 220 m of water
(SAIC 1990b). The dredged material disposed at these sites was from their respective
metropolitan harbors and comprised a wide range of textures including sandy material and
cohesive mud clasts overlying ambient silt-clays and very fine sands. Presumably due to the
relatively deep water at these two sites, the dredged material footprints were in the form of thin
deposits. All parts of the dredged material mounds were colonized by benthic organisms, and
relatively fresh dredged material could be distinguished from older dredged material by the
degree of bioturbation, depth of oxidation of the sediment column, and successional status. Stage
I and HI species were present both on and off the dredged material.
Studies of colonization of experimental sediment trays deployed in the deep-sea, and research on
the effects of natural disturbances such as submarine slumping on the rate of colonization,
diversity, abundance, and biomass of benthic communities provide some information on rates of
recolonization as compared to shallow water systems. Some studies of deep-sea colonization
indicate that early colonies may occur in lower densities than the natural communities, even after
two years (Grassle and Morse-Porteous 1987). These observations suggest that deep-sea
recruitment rates and succession may operate very differently than those in shallow water. In
contrast, observations of repopulation at depths greater than 2,000 m in the Bay of Biscay show
rapid colonization within six months by opportunistic species resulting in abundances in
experimental trays that were five times higher than on the ambient bottom (Desbruyeres et al.
1980). These observations suggest that some deep-water colonization shares attributes with
shallow-water succession. However, when organic-rich, shallow-water sediments were introduced
into an oligotrophic deep-water environment, some studies indicated inhibition of colonization
(Desbruyeres et al. 1980) while others showed a stimulatory or enhancement effect (Griggs et
al. 1969; Jumars and Hessler 1976).
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Predicting the responses of infaunal communities to disposal within the preferred and alternative
sites is difficult because of the wide range of results from the few relevant studies on
recolonization in deep-water environments. However, the dispersion modeling results indicate
that the impact of disposing 6 million yd3 of sand, silt, and clay over a period of one year at all
sites will result in most of the dredged material footprint being less than 10 cm thick. The only
part of the footprint that might be thick enough to cause extensive burial and mortality is the
relatively small central mound formed by rapidly settling cohesive material (see Figure 4.2-6).
Therefore the impact class for the central mound is estimated to be Class I for the preferred and
alternative sites (Table 4.1-1) and is expected to persist throughout the duration of site use.
Infaunal communities at the preferred alternative site are expected to be significantly impacted
(Class I) in a localized area by dredged material disposal. It is likely that the dominant spionid
polychaetes at the site would be more sensitive to sedimentation caused by burial, but because
overall species richness and density is lower (Section 3.3.2.1), the composite impact should be
less than at Alternative Sites 3 and 4. However, recovery or recolonization of the benthic
populations at the preferred alternative site following dredged material disposal might be slower
than in Alternative Sites 3 and 4 because the flux of organic material needed to provide food and
stimulate reproductive processes in benthic invertebrates is generally lower with increasing depth.
The preferred alternative site is approximately 1,200 m deeper than Alternative Sites 3 and 4.
4.2.2.3 Eoifauna
Predicting the effects of dredged material disposal on pelagic and deep-water demersal megafauna
is difficult because most studies on the impacts of dredged material have focused on infaunal
species assemblages and community characteristics in estuarine environments (Wainwright et al.
1992). Few studies have been conducted on megafaunal invertebrates, especially deep-sea species
such as those occurring in the preferred and alternative sites.
Following dredged material disposal, it is likely that fast-swimming pelagic megafauna, such as
euphausiids, siphonophores, and various gelatinous species (cnidarians), would be most affected
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by suspended sediments causing displacement through avoidance of, or escape behavior from,
the disposal plume. Although limited information is available concerning pelagic megafauna
within the general study region, some information can be extrapolated from midwater trawls
conducted by Bence etal. (1992) and from incidental catches in bottom trawls by SAIC (1992b).
In general, some pelagic species of cephalopods (not including market squid) were found by
Bence et al. (1992) at depths greater than 1,200 m, corresponding to depths similar to those of
the preferred and alternative sites. Other pelagic species including euphausiids are patchy in their
distributions within the sites (Bence et al. 1992). However, as noted above, potential impacts
to these pelagic species probably would be insignificant due to their apparent ability to avoid
disposal plumes and distribution over broad depth and geographic ranges.
Similar to the potential impacts noted for infauna (Section 4.2.2.2), slow-moving epifaunal
invertebrates such as seastars and sea pens may become buried and smothered as dredged
material is deposited on the bottom, while more motile benthic taxa such as some crustaceans
may be displaced as an escape response. Also similar to the infauna, recovery and recolonization
of an impacted area will depend on the frequency and severity of the disturbance and the species
involved. Thus, recolonization is expected by individuals able to escape burial, larval
recruitment, and immigration from adjacent, undisturbed areas (e.g., Lissner et al. 1989). Based
on uncertainties and variability in the timing of these events, some recovery may occur within
hours to days, but full recovery could require a few years. However, accumulation of dredged
material should be localized, and there are no known epifaunal species of limited geographic
distribution within the preferred or alternative sites. Therefore, based on an assumption of
significant but localized impacts, particularly to some slow-moving epifauna, potential impacts
(worst case) are projected to be Class I (Table 4.1-1).
There are few differences between the preferred alternative site and Alternative Sites 3 and 4 in
the taxonomic composition, density, and biomass of epifauna (Section 3.3.2.2). The predominant
species within the site (e.g., sea cucumbers, seastars, and brittlestars) are slow-moving and have
the greatest potential for burial and possible mortality. Therefore, potential, localized impacts
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from dredged material disposal at the preferred alternative site are expected to be significant and
designated as Class I, persisting throughout the duration of site use.
4.2.2.4 Fishes
Information on direct impacts of dredged material disposal on fish communities is extremely
limited. Most studies on the effects of dredging and dredged material disposal on fish
communities have focused on larvae and eggs in estuarine environments (Auld and Schubel 1978;
Johnston and Wildish 1981). However, results from these studies suggest that if disposal of
dredged material does not significantly affect these sensitive life stages, then plankton, fishes, or
commercial fisheries also should be unaffected by disposal events.
Pelagic Species
During a disposal event, the greatest impact to pelagic fish species may be from increased
turbidity within the disposal plume, which may limit the feeding efficiency of visually-oriented
predators. However, most of the near-surface pelagic species characteristic of the preferred and
alternative sites are highly mobile species, such as juvenile rockfishes, salmon, tunas, and
mackerels (Section 3.3.3), which may actively avoid the disposal plume. Additionally, some of
these species may be attracted to various prey items (e.g., polychaete worms) which may be
dispersed from the dredged material. Deep-water mesopelagic and bathypelagic species such as
deep-sea smelts and lanternfishes characteristic of the region also should be able to avoid the
disposal plume, although there are no specific studies on avoidance behavior in these fishes.
Therefore, it is estimated that potential impacts of dredged material disposal on pelagic fishes
will be insignificant, and classified as Class IE.
Demersal Species
The number of demersal fish species, density, and biomass at the preferred and alternative sites
is relatively low (Section 3.3.3). Impacts from dredged material disposal are expected to be
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insignificant, particularly due to the relatively high mobility of most species. Some relatively
sedentary demersal species such as eelpouts (Zoarcidae) may be less able to avoid burial from
rapidly accumulating sediments than more mobile species such as rattails (Macrouridae), which
may escape disposal areas entirely. These species also may be displaced from primary deposition
areas, but following recolonization by prey species, eventually may return to areas affected by
disposal. Therefore, because the preferred and alternative sites are located in relatively deep
water and have similar species composition with low fish densities and biomass, potential impacts
are estimated to be localized and insignificant (Class HI) (Table 4.1-1).
The preferred alternative site has similar numbers and types of fishes as Alternative Sites 3 and
4 (Section 3.3.3). These include pelagic, offshore species such as salmon, tunas, and mackerels.
Pelagic species are expected to be least impacted by dredged material disposal due to their high
mobility. Alternatively, demersal species within the site such as codling and eelpouts, have lower
mobility, and thus are expected to be more impacted by disposal than pelagic species. However,
the relatively low numbers of demersal fish species and abundances found within the preferred
alternative site (Section 3.3.3) suggest that impacts will be minimal. Some feeding habitat may
be lost temporarily following disposal activities. However, demersal species should return to the
affected areas following recolonization by prey species. Overall potential impacts of dredged
material disposal on fishes at the preferred alternative site are expected to be insignificant and
designated as Class III.
4.2.2.5 Marine Birds
Information concerning impacts of dredged material disposal to resident and migrating bird
populations is limited. Potential impacts may include ship-following behavior, temporary
reductions in prey items, and visual impairment of marine birds foraging in the vicinity of the
disposal plume.
It is common for many species of birds to follow ships. The regular occurrence of dredged
material-barges and tugs transiting to and from the preferred alternative site may potentially
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distract some marine birds from their normal feeding activities and/or passage routes. However,
the increase in vessel traffic created by dredged material barges is considered insignificant when
compared to existing ship traffic (Commander S. Tiernan, U.S. Coast Guard, pers. comm. 1992).
It is anticipated that many pelagic prey organisms will exhibit various escape behaviors in
response to dredged material disposal. Thus, following a disposal event the immediate area may
contain temporarily reduced populations of some organisms, including juvenile rockfish,
anchovies, euphau'siids, and squid, that are important prey items for marine birds that breed and
nest on the Farallon Islands (Ainley and Boekelheide 1990; Ainley and Allen 1992). Therefore,
foraging success of marine birds may be reduced temporarily following disposal activities.
However, since these prey species characteristically are patchy in their distribution (see Sections
3.3.1 and 3.3.3), localized reductions in prey densities may not significantly affect feeding
behavior of marine birds in the region.
Similarly, it has been suggested that reductions in water clarity following disposal operations may
temporarily inhibit feeding activities of marine birds that typically forage in surface waters (Navy
1992). Computer model results indicated that the finer silt-clay components of dredged material
may require up to approximately 48 hours to reach presumed background concentrations of
1 mg/1, and particle clouds could affect an area over 3,600 km2 (Section 4.2.1.4), thereby
potentially limiting the foraging efficiency of deeper water bird predators. In addition, attraction
of marine birds to positively buoyant particles remaining at the surface following disposal
suggests that some marine birds may expend substantial energy with limited prey acquisition.
However, dispersion modeling results indicated that mean plume depths increase with distance
from the disposal site. Thus, significantly reduced clarity in surface waters likely is restricted
to the immediate release site. Further, permit conditions will ensure that dredged material
contains negligible quantities of buoyant (floatable) debris. Therefore, these potential impacts
should be localized and of relatively short duration; consequently, they are not expected to affect
significantly the breeding, feeding, or passage of marine birds that occur broadly throughout the
study region.
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Dredged material proposed for ocean disposal will be tested for bioaccumulation potential
according to "Green Book" (EPA/COE 1991) protocols. Material that exhibits a potential for
contaminant bioaccumulation will not be discharged at an ODMDS. Therefore, it is assumed that
dredged material disposal at any of the alternative sites will not affect bioaccumulation or
biomagnification of contaminants.
Based on the above information, dredged material disposal impacts on marine birds are classified
as Class III. The types of impacts are expected to be similar at the preferred and alternative
sites; therefore differences in disposal consequences to marine birds should be related primarily
to differences in the relative abundance of marine bird species within each site (see
Section 3.3.4).
The preferred alternative site is located approximately 25 nmi from the breeding and nesting
grounds of the Farallon Islands. As compared to Alternative Sites 3 and 4, survey results suggest
that the preferred alternative site receives the highest use by marine birds (Section 3.3.4). Thus,
potential impacts (Class HI) to marine birds are expected to be greatest but still insignificant at
the preferred alternative site as compared to Alternative Sites 3 and 4.
4.2.2.6 Marine Mammals
The potential impacts of dredged material disposal to marine mammals are expected to be similar
to those of marine birds. These impacts include temporary impairment of foraging activities
attributable to disturbances caused by disposal and subsequent reductions in water clarity (see
Section 4.2.2.5).
An additional potential impact may be alteration of marine mammal passage routes to avoid noise
from ship traffic or from increased water turbidity during or following disposal activities.
Further, noise may influence non-auditory physiology (Fletcher 1971), increasing the stress
response and lowering resistance to disease. Because ship noise levels correlate generally with
vessel size, speed, and load, larger, faster ships underway with full loads (or towing/pushing
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loads) may emit more sound than smaller, slower, and lighter ships (Richardson 1991). In
addition, ships with older auxiliary equipment such as generators and compressors radiate more
noise than modern, well-maintained vessels (Richardson 1991). Some studies have suggested that
the noise associated with increased vessel traffic may affect marine mammal migration routes.
Specifically, it has been suggested that increased ship traffic in Japanese waters disturbed
migration routes of minke and Baird's beaked whales (Nishiwaki and Sasao 1977). Baleen
whales such as grays, humpbacks, and blues sometimes move quickly away from approaching
vessels, although there is little evidence that they are affected after the vessel has passed.
However, based on limited data, Richardson (1991) suggests that ship noise has little impact on
pinnipeds. Although vessel traffic may potentially impact marine mammals, the increase in ship
traffic attributable to dredged material barges is considered insignificant in relation to existing
traffic (Commander S. Tiernan, U.S. Coast Guard, pers. comm. 1992).
Dohl et al (1983) indicated that gray whales may change their course to avoid turbid plumes
caused by run-off from rivers and bays. Similarly, experiments with dolphins (Tursiops
truncatas) suggested that they were able to detect and avoid oil patches using echolocation,
especially if air bubbles were present in the patch (Geraci and St. Aubin 1987). Thus, it is
possible that marine mammals capable of detecting differences in water turbidity may alter their
route to avoid a disposal area.
However, vessel noise and plume impacts to marine mammals are temporary and localized to the
immediate vicinity of the disposal site, and are not expected to affect breeding, nursery, or
feeding areas for adults or juveniles. Thus, potential impacts to marine mammals are
characterized as Class HI (Table 4.1-1). These potential impacts are similar for the preferred and
alternative sites. As described for marine birds, differences in potential disposal effects on
marine mammals are based on comparisons of their relative abundances within each of the sites
(see Section 3.3.5).
Survey results suggest that the preferred alternative site receives the highest use by marine
mammals (Section 3.3.5) as compared to Alternative Sites 3 and 4. Thus, impacts to marine
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mammals are expected to be greatest but still insignificant at the preferred alternative site as
compared to Alternative Sites 3 and 4.
4.2.2.7 Threatened. Endangered, and Special Status Species
As described in Section 3.3.6, nine known threatened or endangered species occur somewhat
regularly in the general study region. These include five whale species (gray, humpback, blue,
finback, and sperm), one pinniped species (northern sea lion), two bird species (Peregrine falcon
and California brown pelican), and one fish species (winter-run chinook salmon).
Potential impacts of dredged material disposal on whale and pinniped species may include
temporary impairment of feeding activities and avoidance of barge vessels and the disposal
plume, as described in Section 4.2.2.6. Impacts to Peregrine falcon include the potential for ship
following behavior which may affect normal feeding or passage activities. California brown
pelican and winter-run chinook salmon populations occur primarily over the continental shelf (see
Section 3.3.6), and thus are not expected to be impacted by disposal activities within any of the
sites.
Due to the temporary nature and localized spatial distribution of disposal activities, potential
impacts are estimated to be insignificant (Class III). The types of potential impacts are expected
to be similar at the preferred and alternative sites. However, differences in disposal consequences
between sites can be identified based on the relative abundances of threatened or endangered
species (See Section 3.3.6) as described below.
Compared to Alternative Sites 3 and 4, the preferred alternative site is a relatively high use area
for threatened or endangered marine bird and mammal species (Section 3.3.6). Therefore,
potential impacts to threatened or endangered species are expected to be higher but still
insignificant at the preferred alternative site than at Alternative Sites 3 and 4.
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4.2.2.8 Marine Sanctuaries
Six designated national marine sanctuaries, refuges, or special biological resource areas occur
within the study region. One or more of these areas lies within 5 nmi of the preferred and
alternative sites (Section 3.3.7). These areas contain a wide variety of sensitive habitats and
biological resources including threatened and endangered species.
Disposal of dredged material from San Francisco Bay will not occur within the boundaries of any
of the national marine sanctuaries, refuges, or areas of special biological significance. However,
because the dredged material barges must transit through one or more of the marine sanctuaries
to reach any of the sites, accidents or overflow from the barges could result in inadvertent
releases of dredged material within sanctuary boundaries.
The volumes of dredged material released by single or isolated incidences likely would be small
(e.g., 6,000 yd3 for a single barge load) and environmental consequences would depend on
location of the discharge, rate and direction of plume dispersion, and specific resources in the
path of dispersing material. Dredged material released within or immediately adjacent to a
sensitive habitat, and repeated discharges over a longer time period, could result in more
significant environmental impacts. However, the probability of these circumstances can be
reduced or mitigated by specifying that barges use specific transit routes that avoid sensitive
habitats (Class II impact).
The Farallon Islands lie in the direct route of barges transiting from San Francisco Bay to the
preferred alternative site. Accidental discharge or overflow of dredged material near the Islands
should be avoided. Mitigative measures as discussed above indicate that potential disposal
impacts at the preferred alternative site are Class n (i.e., significant adverse impacts that can be
mitigated to insignificant levels).
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4.2.3 Effects on Socioeconomic Environment
The following sections discuss the potential consequences of the proposed action on the
socioeconomic environment associated with the preferred and alternative site. Resources
addressed include commercial fishing, commercial and recreational shipping, mineral and oil and
gas development, military usage, recreational activities, cultural resources, and public health and
welfare.
4.2.3.1 Commercial and Recreational Fishing
Analysis of the MMS/CDFG Commercial Fisheries Database (1992) and CDFG Recreational
Fisheries Database (1992) indicated that the majority of commercial and recreational fisheries are
located predominantly in the continental shelf region. Extremely limited fishing activity occurs
over the slope areas corresponding to the preferred and alternative sites (Section 3.4.1). The
commercial fishery data suggest that some minor catches of tunas, mackerels, and some flatfishes
were taken from the region of Alternative Sites 3 and 4, while tunas and mackerels were taken
in low numbers in the region of the preferred alternative site (MMS/CDFG Commercial Fisheries
Database 1992).
Most species targeted by commercial or recreational fishermen in offshore areas such as the
alternative sites are fast-moving pelagic fishes such as salmon, tunas, and mackerels. According
to Bence et al. (1992), juvenile rockfishes are abundant offshore in the preferred and alternative
sites but are somewhat more abundant in the region of the preferred alternative site. However,
because all the sites are located far offshore (e.g., 45 to 55 nmi), where most commercial and
recreational fishing is limited, and because these species are mobile and should be able to avoid
the disposal plumes, there should not be any significant impacts on these fisheries at any of the
sites. Therefore, impacts are estimated to be Class HI.
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Historical catches within the region of the preferred alternative site are somewhat lower than
those for the regions of Alternative Sites 3 and 4. Thus, potential fishery impacts at Alternative
Site 5 may be relatively lower as compared to Alternative Sites 3 and 4.
4.2.3.2 Commercial Shipping
The preferred and alternative sites are located outside of designated commercial vessel traffic
lanes and away from any restricted passage areas, precautionary zones, or anchorages for
commercial shipping. Dredged material barges using an ODMDS would represent additional
vessel traffic within the study region. However, the magnitude of this additional ship traffic is
expected to be negligible (Section 3.4.3), representing a Class in impact that is not expected to
vary significantly between sites. Furthermore, because the ultimate purpose of dredging
operations is to provide adequate water depths and access to vessel traffic for channels and berths
within the Bay, the proposed action could be considered a Class IV (beneficial effect) impact.
4.2.3.3 Mineral or Energy Development
As discussed in Section 3.4.5, no oil and gas development activities occur within the general
region of the preferred or alternative sites, and the closest potential lease blocks are more than
200 miles from the sites. This is based on current moratoriums on development, and
technological limitations which restrict these activities to depths shallower than approximately
300 to 400 m (Section 3.4.5). The average depth at the preferred alternative site is over 2,000
m. Further, because of the deep bottom depths at the sites, no other mineral development
activities are likely to occur. Therefore, use of any of the sites for dredged material disposal will
not interfere with or impact existing mineral resources or energy development operations in the
foreseeable future (Class HI impact).
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4.2.3.4 Military Usage
Military usage of the LTMS study region, including areas in the vicinity of the preferred and
alternative sites, is considered to be significant (Section 3.4.4). In particular, submarine operating
areas are delineated near but outside of Alternative Sites 3, 4, and 5 (Figure 2.1-5). With
exception of operating area Ul which is used infrequently, submarine operating areas U2 through
U5 are used by the Navy an average of 10 days per month for trial diving exercises and
post-overhaul checkouts. However, because the preferred and alternative sites are located outside
of the operating areas, dredged material disposal at any of the sites is expected to have negligible
impacts (Class III) on military operations in the region. Use of an ODMDS is not expected to
interfere with any other military vessel traffic or training exercises. Although the preferred
alternative lies near submarine operating area U4, use of the site for dredged material disposal
is not expected to adversely impact military activities (Class III impact).
4.2.3.5 Recreational Activities
Recreational activities in the general vicinity of the preferred and alternative sites are centered
around the Farallon Islands. Although specific data are unavailable, recreational activities such
as sailing, fishing, or whale watching, within the boundaries of the alternative sites are generally
infrequent (Section 3.4.6). Therefore, potential impacts from use of the alternative sites for
dredged material disposal are considered insignificant. Potential effects of dredged material barge
traffic on recreational boating or fishing within the vicinity of the Farallon Islands could be
mitigated by requiring barges to stay within defined traffic lanes and avoid the areas immediately
around the Farallon Islands.
Of the three alternative sites, the preferred alternative lies closest to the Farallon Islands. Thus,
relative to Alternative Sites 3 and 4, potential impacts to recreational activities may be greatest
at the preferred alternative site. However, as noted, restricting dredged material barges to
specified traffic lanes could mitigate potential impacts (Class II).
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4.2.3.6 Cultural and Historical Resources
As discussed in Section 3.4.7, no known shipwrecks of cultural or historical importance, or other
man-made cultural or historical resources, are located within the immediate vicinity of the
preferred or alternative sites. Therefore, designation of an ODMDS is not expected to have any
significant effect on historical resources. Oceanic tours or expeditions by wildlife and naturalists
groups are concentrated around the Farallon Islands and Cordell Banks. Potential interferences
from dredged material disposal operations would be limited to minor navigational conflicts with
dredged material barges in the vicinity of the Farallon Islands. However, these potential
interferences could be mitigated by specifying barge transit lanes that avoid the vicinity of the
Islands. Therefore, these potential impacts are considered Class II.
4.2.3.7 Public Health and Welfare
There are no obvious impacts on public health and welfare associated with the designation of an
ODMDS (Class III). Collisions between a dredged material barge and a commercial or
recreational vessel, or operation of a dredged material barge in the Gulf of the Farallones during
extreme weather conditions, could endanger human lives. However, these events are expected
to be rare (Section 3.4.3). Conversely, maintenance dredging of navigational channels within San
Francisco Bay supports the continued operation of several ports and, consequently, promotes local
and regional commerce.
Potential impacts on public health and welfare associated with disposal at the preferred alternative
site are insignificant (Class III) due to the projected rare occurrence of vessel collisions near the
site.
4.3 No-Action Alternative
As stated in the Purpose of and Need for Action (Section 1.2), it is the intent of this EIS to
identify and designate an ODMDS that is suitable for approved Federal and permitted dredging
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projects. Selection of the No-Action alternative would not fulfill the LTMS goal of providing
a long-term, multi-user ODMDS for disposal of dredged material from San Francisco Bay. In
the absence of a designated ODMDS, or Section 103 interim ODMDS, other disposal options,
such as within the Bay or at nonaquatic sites, would be required for dredged material.
Alternatively, planned dredging would have to be delayed until a suitable disposal option is
identified.
Selection of the No-Action Alternative per se would result in no impacts or changes to the
existing environmental conditions at the preferred or alternative sites due to dredged material
disposal operations. However, the consequences of the No-Action Alternative may cause varying
environmental impacts. For example, non-ocean disposal options, such as the use of sites within
the Bay or nonaquatic sites also would result in location-specific environmental impacts. At this
time, the ability of non-ocean sites to receive the volume of dredged material planned for the next
50 years is not known. However, the nature and extent of potential impacts at nonaquatic sites
and sites within the Bay presently are being evaluated by the In-Bay and Nonaquatic/Reuse
LTMS Work Groups.
Disposal of dredged material at a Section 103 ocean disposal site would result in some impacts
on conditions at the Section 103 Site, although the magnitude of these impacts would depend on
the volume and characteristics of the dredged material and the physical and biological conditions
at the particular site. Cessation of dredging would result in shoaling within the main shipping
channels, thus impairing and potentially endangering shipping operations within the Bay, with
associated impacts on the economy of the region and the logistical needs of the Navy
(COE 1990b).
Selection of the No-Action Alternative would preclude the use of ocean disposal as a long-term
management option. Selection of this alternative would result in a failure to meet LTMS
objectives and would have unknown consequences (COE 1992a). Therefore, EPA proposes to
designate an ODMDS based on the preferred alternative described in this DEIS.
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4.4 Other Ocean Disposal Alternatives
This section describes the potential environmental consequences of dredged material disposal at
Alternative Sites 3 and 4.
4.4.1 Effects on the Physical Environment
These sections address potential effects of dredged material disposal at the other ocean disposal
alternatives on regional meteorology and air quality, physical oceanography, water quality, and
sediment quality.
4.4.1.1 Air Quality
Potential impacts to regional air quality associated with dredged material disposal at Alternative
Sites 3 and 4 were evaluated using the same EPA air quality model and assumptions as
summarized in Section 4.2.1.1 for the preferred alternative site. As noted for the preferred
alternative site, no significant effects on air quality were indicated along the preferred route of
the barges transporting dredged material to Alternative Sites 3 and 4 (Table 4.2-1), therefore
representing a Class in impact.
4.4.1.2 Physical Oceanography
Similar to the preferred alternative site, the use of Alternative Sites 3 and 4 would not have any
measurable effect on the regional or site-specific physical oceanographic conditions, and therefore
is predicted to represent a Class HI impact. The prevailing oceanographic processes will strongly
influence the dispersion and long-term fate of dredged material discharged at the alternative sites.
The overall circulation patterns that would affect disposal activities are as summarized in
Section 4.2.1.2.
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In general, poleward current flows are typical of the upper 1,000 m of the water column over
most of the year, with the strongest flows over the inner slope region, including the general area
of Alternative Sites 3 and 4 (Section 3.2.2). Near-bottom currents in the vicinity of Alternative
Site 3 (Mooring D) were characterized by relatively low speeds and thus were less likely to erode
sediments than currents measured at Station E near the eastern boundary of Study Area 5
(Section 3.2.2). No specific information from the current meter program is available for
Alternative Site 4. Based on the data presented in Section 3.2.2, it is very unlikely that
upwelling would be a significant mechanism at either of the alternatives to transport dredged
material from slope to shelf environments.
4.4.1.3 Water Quality
Potential impacts on water quality from dredged material disposal at Alternative Sites 3 and 4
were addressed by disposal plume modeling (SAIC 1992e), as discussed in Section 4.2.1.3 for
the preferred alternative. Similar to the preferred alternative, changes in water quality such as
localized increases in turbidity, reductions in light transmittance, and increases in dissolved and
paniculate concentrations of trace contaminants that could result from dredged material disposal
are expected to be transient, and therefore represent Class El impacts.
Alternative Site 3
Results from the water quality model (SAIC 1992e) indicated that dredged material plumes
comprising class 1 through class 6 particles would disperse over areas of 13 to 7,855 km2 in the
vicinity of the site, (assuming a conservative background suspended particle concentration of
1 mg/1, conservative dispersion rates, and conservative initial and background concentrations
(Table 4.2-3). The mean plume visitation frequencies over these affected areas would range from
approximately 1 to 4%, and the predicted maximum exposure times would range from 1.0 to 42
hours for individual particle size classes. The mean cloud depth over the affected area for
individual particle size classes would range from 54 m for clay-silt particles to approximately
1,300 m for fine and medium sand particles (Table 4.2-3). The areas affected and the water
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column residence times would be expected to vary as a function of the particle size. Larger
particles with higher sinking rates would have shorter residence times and deeper cloud depths,
whereas smaller particles with lower sinking rates would have longer residence times and
shallower cloud depths because stronger and more variable near-surface currents would disperse
the plumes over relatively larger areas. Dredged material disposal at Alternative Site 3 would
be expected to result in concentrations from approximately 1 to 2 mg/1 of fine-grained (class 6)
suspended particles at the MBNMS boundary for 0.2 to 5% of the discharge events, and
concentrations from approximately 1 to 2 mg/1 of fine-grained particles at the GOFNMS
boundary for 1 to 5% of the discharge events. Particle concentrations at the CBNMS boundary
were not expected to be elevated above background concentrations (Figure 4.2-3). Clouds of
larger dredged material particles would not be expected to cross any of the Sanctuary boundaries.
Based on the above information, effects on water quality from dredged material disposal at
Alternative Site 3 are considered Class HI because the plumes are expected to disperse within
48 hours of discharge, no build-up or accumulation of particles within the water column is
expected, and changes to water quality parameters (e.g., turbidity, light transmittance, dissolved
oxygen concentrations) are expected to be transient and localized within the discharge plume.
Disposal operations should have insignificant effects on concentrations of contaminants in the
water column, given that only dredged material of suitable quality will be permitted for disposal
at the ODMDS.
Alternative Site 4
The water quality model results (SAIC 1992e) indicated that disposal plumes comprising class
1 through class 6 particles would affect areas up to 7,708 km2, although the mean visitation
frequency over this area would range from approximately 1 to 5% (Table 4.2-3). The mean
cloud depth would vary from 55 to 1,511 m, and the maximum exposure time would range from
approximately 1.0 to 43 hours. Use of Alternative Site 4 would result in concentrations from
approximately 1 to 2 mg/1 of fine-grained particles at the GOFNMS and MBNMS boundaries for
approximately 0.2 to 1.0% of the discharge events (Figure 4.2-4). Clouds of coarser particles
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would not be expected to reach the sanctuary boundaries. Effects on water quality from dredged
material disposal at Alternative Site 4 are considered Class HI, similar to those discussed for
Alternative Site 3.
4.4.1.4 Geology and Sediment Characteristics
Potential impacts on sediment characteristics from dredged material disposal at Alternative Sites
3 and 4 were evaluated by deposition modeling (SAIC 1992e) as discussed in Section 4.2.1.4 for
the preferred alternative site. Specific effects of dredged material disposal on long-term changes
to the grain size and chemical characteristics of the bottom sediments cannot be determined
quantitatively. Although localized and extended impacts to grain size may be expected,
significant effects on sediment quality would not be anticipated, given that only dredged material
of suitable quality will be approved for disposal at an ODMDS.
Alternative Site 3
The deposition model (SAIC 1992e) calculated that disposal of six million yd3 over a one-year
period at Alternative Site 3 would result in bottom deposits of clay-silt and mostly sand material
with thicknesses greater than 1 mm covering areas of approximately 360 and 620 km2,
respectively. The maximum deposit thicknesses for these material types would be approximately
730 and 62 mm, respectively, and the mean deposit thicknesses over these areas would be 7.9
and 4.5 mm, respectively. The model-predicted bottom deposit with thicknesses greater than or
equal to 100 mm would cover an area of 5.91 km2 based on a discharge of 6 million yd3 of silt-
clay materials over a one-year period.
Clay-silt material would produce the greatest thickness (approximately 70 cm) near the disposal
site center due to deposition of rapidly-settling clumps. The maximum thickness of mostly sand
material is an order of magnitude lower (approximately 60 mm). Because the alternative site
boundaries were defined to encompass the 10 mm deposit thickness contour for clay-silt material
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(Section 2.2), deposits of both clay-silt and mostly sandy material with thicknesses greater than
10 mm would, by definition, be contained within site boundaries.
Deposition of dredged material could result in a significant localized alteration of the bottom
sediment grain size properties (Class I impact; Table 4.1-1). The extent of this alteration would
depend on the grain size distribution of the dredged material. Although it is desirable to
minimize these differences, it is likely that some of the material disposed at the ODMDS would
contain sand-sized sediments that do not occur naturally at the site. This impact would be
expected to persist at least for the duration of the site use assuming continuous disposal
schedules. Subsequent return to pre-disposal conditions could result from extended interruption
of disposal operations and natural particle deposition, dispersion, and mixing processes
(Section 4.2.2.2). Contours for the model-predicted 1 mm and 10 mm deposit thicknesses
extended towards the northwest (Figure 4.2-6), but there was no indication that these deposits
would affect Pioneer Seamount (to the west of Alternative Site 3) or other hard-bottom features
that might occur in the vicinity of the site.
Effects from dredged material disposal on the chemical characteristics of the site sediments
cannot be determined accurately because the organic content and trace contaminant concentrations
in the dredged material are not known. Conclusions that disposal operations at Alternative Site 3
would represent a Class III impact on sediment quality assume that the dredged material has
satisfied testing criteria designed to establish that the material is of suitable quality for ocean
disposal (EPA/COE 1991).
Alternative Site 4
The deposition model (SAIC 1992e) predicted that disposal of six million yd3 per year of clay-silt
and mostly sand type material at Alternative Site 4 would result in bottom deposits with
thicknesses greater than 1 mm covering areas of 280 and 500 km2, respectively. The maximum
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deposit thicknesses for these material types would be approximately 790 and 69 mm,
respectively, and the mean deposit thickness over these areas would be 9.8 and 5.2 mm,
respectively. The model-predicted bottom deposit with thicknesses greater than or equal to 100
mm would cover an area of 5.88 km2 based on a discharge of 6 million yd3 of silt-clay materials
over a one-year period.
Effects from dredged material disposal at Alternative Site 4 on sediment grain size also are
expected to represent a Class I impact. This impact also would be relatively localized (i.e.,
corresponding approximately to the 10 mm footprint contour), but would persist for the duration
of site use assuming a continuous disposal schedule. Deposits with thicknesses between 1 and
10 mm would extend in a northwest direction beyond the site boundaries (Figure 4.2.6). The
extent of hard-bottom features in the adjacent portion of Pioneer Canyon presently is not known.
Regardless, it is unlikely that deposition of dredged material at a rate of 1 to 10 mm per year on
a hard substrate would have a significant impact on an attached epifaunal community which
might occur within the area (e.g., Lissner et al. 1991). Effects on sediment quality are considered
a Class HI impact, as noted above for Alternative Site 3, and similar to the magnitude of effects
at Alternative Sites 3 and 5.
4.4.2 Effects on Biological Environment
The following sections discuss the potential consequences of the proposed action on the
biological environments of Alternative Sites 3 and 4.
4.4.2.1 Plankton
As noted for the preferred alternative (Section 4.2.2.1), impacts on plankton from rapidly settling
dredged material particles such as sand and clay-silt aggregates are expected to be minimal
because of relatively limited exposure times (minutes to hours). Longer exposure times and
potentially greater impacts would be expected from slower-settling, fine-grained particles which
may concentrate more in regions of neutral buoyancy, such as the pycnocline. However, based
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on the transient nature of the dredged material plume and the characteristically high seasonal and
annual variability in plankton communities, overall impacts are expected to be insignificant and
classified as Class III.
Alternative Site 3
Significant seasonal and annual variations in productivity, standing crop, and species composition
of plankton communities are evident from existing data of the general study region
(Section 3.3.1). Phytoplankton and zooplankton (including ichthyoplankton) abundances vary
seasonally, but are highest inshore of Alternative Site 3 and the lower slope environment.
Therefore, for plankton, no significant effects (Class III) on plankton from the proposed action
are expected at this site (Table 4.1-1).
Alternative Site 4
Based on existing data on plankton communities of the general study region, no differences can
be distinguished in the productivity, standing crop, or species composition between Alternative
Sites 3 and 4. Therefore, potential impacts to plankton at this site also are classified as
insignificant (Class HI).
4.4.2.2 Infauna
As described in Section 4.2.2.2, potential impacts to infauna following dredged material disposal
include burial and smothering and will be influenced by the frequency and severity of disturbance
and the capacity for species Decolonization after the disposal event. Extensive burial would be
expected within a relatively small, central mound at each of the sites regardless of which
alternative was selected. Thus, relative differences in potential impacts are based on differences
in infaunal compositions and densities within each of the sites.
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Alternative Site 3
Burial and mortality of infauna at Alternative Site 3 are expected to be significant (Class I)
within the boundary of the 10 cm depositional area (e.g., up to 5.91 km2 for a discharge of
6 million yd3 per year) as noted above (Table 4.1-1 and Figure 4.2-6). No species that are known
to be unique to the area or geographically limited in distribution are found at this site or at
Alternative Sites 4 or 5. However, the high abundances of filter-feeding amphipods found in
Alternative Site 3, among other deep-water parts of Study Area 3, were not found at any other
sampled locations within the study region. Overall infaunal densities are similar to Alternative
Site 4, but slightly higher than Alternative Site 5 (Section 3.3.2.1). Therefore, the impacts of
dredged material disposal at Alternative Site 3 are expected to be similar to those at Alternative
Site 4 but somewhat greater than those at Alternative Site 5 due to the relative differences in
infaunal densities.
Alternative Site 4
Similar to Alternative Site 3, impacts of dredged material disposal at Alternative Site 4 are
expected to be significant (e.g., up to 5.88 km2 for a discharge of 6 million yd3 per year) (Class
I) but localized. Based on infaunal densities (Section 3.3.2.1) the impacts at Alternative Sites
3 and 4 are expected to be similar but somewhat higher than at Alternative Site 5. However,
Alternative Site 4 does not contain the high abundances of filter-feeding amphipods found at
Alternative Site 3.
4.4.2.3 Epifauna
Disposal impacts to slow-moving epifaunal species such as seastars and sea pens are expected
to be more significant as compared to impacts on more mobile species (e.g., crustaceans) which
may respond to disposal events with various escape behaviors (see Section 4.2.2.3). The
taxonomic composition, density, and biomass of epifaunal species are similar at the preferred
alternative site and Alternative Sites 3 and 4. Localized burial of epifauna would occur at each
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of the sites within the 10 cm depositional contour. Thus, potential impacts are projected to be
Class I at each alternative site.
Alternative Site 3
Alternative Site 3 contains moderate numbers of species, abundances, and biomass of epifaunal
organisms (Section 3.3.2.2). Predominant species, including sea cucumbers, seastars, and
brittlestars, are all slow-moving and would have the greatest potential for burial and possible
mortality. Based on this assumption and the conservative nature of the modeling, impacts are
estimated to be significant (Class I), and localized within the 10 cm depositional boundary at this
site, but are expected to persist throughout the duration of site use.
Alternative Site 4
Similar to Alternative Sites 3 and 5, impacts of dredged material disposal at Alternative Site 4
are expected to be significant (Class I) but localized. This is based on similar epifaunal species
and densities at these sites (Section 3.3.2.2).
4.4.2.4 Fishes
As discussed in Section 4.2.2.4, potential impacts to pelagic fishes following disposal activities
could include a decrease in feeding efficiency and avoidance behaviors. Potential disposal
impacts to demersal species could include burial (for relatively sedentary species), displacement,
and temporary habitat loss. However, because fish densities and biomass within the alternative
sites are low, potential impacts are estimated to be insignificant (Class III).
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Alternative Site 3
Pelagic fishes such as salmon, tunas, and mackerels that occur in offshore areas such as
Alternative Site 3 should not be impacted due to their high mobility (Class HI). Moreover, this
site contains relatively low numbers of demersal fish species and abundances (Section 3.3.3).
Although some feeding habitat may be temporarily lost following a disposal event, demersal
fishes are expected to return to these affected areas after a disposal event. Most species at this
site should be able to avoid impacted areas and would not be affected significantly by dredged
material disposal. Therefore, potential impacts are classified as Class in.
Alternative Site 4
The number of species, densities, and biomass of fishes in Alternative Site 4 is similar to
Alternative Site 3 (Section 3.3.3); therefore, potential impacts of dredged material disposal at
Alternative Site 4 also are expected to be insignificant and classified as Class in.
4.4.2.5 Marine Birds
Potential impacts on marine birds from dredged material disposal are discussed in Section 4.2.2.5.
These impacts are expected to be similar and insignificant at the preferred and alternative sites.
Therefore, the discussion of differences in disposal consequences to marine birds focuses on
abundances of marine bird species within each site (see Section 3.3.4).
Alternative Site 3
Alternative Site 3 is located approximately 25 nmi from the Farallon Islands, an important
breeding, nesting, and feeding area for marine birds (Section 3.3.4). The combined results from
recent survey efforts (Ainley and Boekelheide 1990; Ainley and Allen 1992; Jones and
Szczepaniak 1992) indicate that Alternative Site 3 receives relatively higher use by marine birds
as compared to Alternative Site 4 but relatively lower use than the preferred alternative site
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(Section 3.3.4). Thus, the extent of potential impacts to marine birds occurring at Alternative
Site 3 may be relatively greater than at Alternative Site 4 and relatively less than at the preferred
alternative site. However, based on the transient nature of potential impacts, overall effects are
estimated to be insignificant and classified as Class in.
Alternative Site 4
Of the three alternative sites, Alternative Site 4 is located the greatest distance (approximately
30 nmi) from the Farallon Islands breeding and nesting grounds. In contrast to Alternative Site 3
and the preferred alternative site, survey results for Alternative Site 4 indicate that it is a
relatively low use area for marine birds (Section 3.3.4). Therefore, it is expected that fewer
potential impacts (Class in) to marine birds would occur at Alternative Site 4 than at the
preferred alternative or Alternative Site 3.
4.4.2.6 Marine Mammals
Potential impacts on marine mammals from dredged material disposal are discussed in Section
4.2.2.6. These impacts are expected to be similar and insignificant at the preferred and
alternative sites. Thus, as for marine birds, differences in potential disposal effects on marine
mammals are based on relative abundances of marine mammal species within each site (see
Section 3.3.5).
Alternative Site 3
Alternative Site 3 does not appear to be within an important marine mammal passage area,
although it may be important as a feeding ground for some marine pinnipeds (Section 3.3.5).
The combined results from historic (Bonnell et al. 1983; Dohl et al. 1983) and recent marine
mammal surveys (Ainley and Allen 1992; Jones and Szczepaniak 1992) indicate that Alternative
Site 3 receives intermediate use by marine mammals as compared to lower use of Alternative
Sites 4 and higher use of the preferred alternative (Section 3.3.5). Therefore, although impacts
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at the alternative sites can be classified as Class III, based on the transient nature of potential
effects, disposal impacts on marine mammals are expected to be greater at Alternative Site 3 than
at Alternative Site 4, but less than at the preferred alternative site.
Alternative Site 4
Alternative Site 4 is not located in close proximity to marine mammal breeding or feeding
grounds or important passage areas (Section 3.3.5). In contrast to Alternative Site 3 and the
preferred alternative, survey results indicate that Alternative Site 4 is a low use area for marine
mammals (Section 3.3.5). Thus, potential impacts on marine mammals are expected to be lower
(Class III) within Alternative Site 4 as compared to Alternative Site 3 and the preferred
alternative site.
4.4.2.7 Threatened, Endangered, and Special Status Species
As discussed in Section 4.2.2.7, the types of potential impacts on threatened and endangered
species are expected to be similar at each of the alternative sites. Thus, differences in disposal
consequences to these species are based on their relative abundances within each site.
Alternative Site 3
Compared to Alternative Site 4 and the preferred alternative, Alternative Site 3 is an intermediate
use area for the endangered cetacean and threatened pinniped species; it is a relatively low use
area for endangered marine bird and fish species (Section 3.3.6). Therefore, the magnitude of
potential impacts at Alternative Site 3 is expected to be greater than at Alternative Site 4 but less
than at the preferred alternative site. However, as noted for marine birds and mammals, the
transient nature of potential effects represents insignificant impacts (Class III).
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Alternative Site 4
Alternative Site 4 is a relatively low use area for threatened or endangered marine mammals,
birds, and fish (Section 3.3.6). Therefore, the magnitude of potential impacts on threatened or
endangered species is expected to be lowest at Alternative Site 4 (Class in) as compared to
Alternative Site 3 and the preferred alternative site.
4.4.2.8 Marine Sanctuaries
As discussed in Section 4.2.2.8, there are six national marine sanctuaries, refuges, or special
biological resource areas within the study region. These areas contain sensitive habitats in
addition to some biological species that are threatened or endangered (Section 3.3.7). Although
disposal of dredged material will not occur within any of these sensitive areas, there is some
concern that accidental overflow or discharge of dredged material in the vicinity of sensitive
areas may occur as dredged material barges transit to the disposal site. EPA and COE will
address these concerns through the site management plan and special conditions on permits for
individual dredging projects. Therefore, potential impacts at the alternative sites are expected to
be Class II (significant adverse impacts that can be mitigated to insignificance).
Alternative Site 3
Alternative Site 3 is located south of the GOFNMS and west of MBNMS. Dredged material
barges must pass through one or both of these sanctuaries in route to and from this site. To
reduce or mitigate potential impacts caused by accidental overflow of dredged material from the
barges, specific transit routes can be identified that avoid sensitive areas within the sanctuaries
(e.g., Farallon Islands). Therefore, impacts at Alternative Site 3 are considered Class El.
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Alternative Site 4
Alternative Site 4 is located in a similar position as Alternative Site 3 (i.e., south of the
GOFNMS and west of MBNMS). Therefore, potential impacts on sensitive habitats within
sanctuaries from use of Alternative Site 4 also are designated Class n because specific transit
routes can be identified that avoid sensitive areas.
4.4.3 Effects on Socioeconomic Environment
4.4.3.1 Commercial and Recreational Fishing
As discussed in Section 4.2.3.1, the potential impacts of dredged material disposal on pelagic and
demersal fisheries are limited due to the high mobility of pelagic fishes that may avoid disposal
plumes, location of many demersal fish species inshore of the alternative sites, and overall
historical record of limited catches within any of the sites.
Alternative Site 3
In the vicinity of Alternative Site 3, most of the commercially and recreationally important
pelagic fishes, such as tunas and mackerels, are expected to be able to avoid dredged material
disposal sites. Therefore, the impacts on fisheries for pelagic species would be negligible (Class
III). Similarly, fisheries for demersal fishes, including some flatfishes, are located primarily
inshore of Alternative Site 3 (Section 3.4.1), indicating that potential impacts to these species also
would be insignificant (Class III).
Alternative Site 4
Commercial and recreational fishery resources in the region of Alternative Site 4 are very similar
to those of Alternative Site 3. Therefore, potential impacts are expected to be Class in, because
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targeted pelagic species should be able to avoid disposal plumes, and the majority of demersal
fishery resources are located inshore of the alternative sites.
4.4.3.2 Commercial Shipping
All of the alternative sites lie outside of designated commercial vessel traffic lanes (see Section
4.2.3.2). The additional vessel traffic represented by dredged material barges transiting to and
from an ODMDS is expected to be negligible (Cmdr. Tiernan, USCG, pers. comm. 1992)
(Class III) and is expected to vary only slightly among sites.
Alternative Site 3
Alternative Site 3 is located outside of commercial vessel traffic lanes. Therefore, impacts to
commercial shipping activities created by use of an ODMDS are considered to be Class in.
Alternative Site 4
Alternative Site 4 also is located outside of commercial traffic lanes. Therefore, similar to
Alternative Site 3, potential impacts on commercial shipping activities are considered to be
Class HI.
4.4.3.3 Mineral or Energy Development
Mineral or energy development activities are currently restricted to depths less than
approximately 400 m, whereas bottom depths at the alternative sites are greater than
approximately 1,400 m (Section 3.4.5). In addition, the closest potential oil and gas lease block
is located over 200 miles from the alternative sites. Therefore, use of either of the alternative
sites for dredged material disposal is not expected to interfere with existing mineral resources or
energy development activities (Class in impact).
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Alternative Site 3
Due to its deep depths (approximately 1,500 m) and its distant location (over 200 miles) from
the closest potential lease block, impacts on mineral or energy development attributable to
dredged material disposal at Alternative Site 3 are considered to be Class IE.
Alternative Site 4
Alternative Site 4 also is located in deep water (greater than 1,500 m) and is over 200 miles from
the nearest potential lease block. Therefore, impacts on potential mineral or energy development
activities also are considered to be Class HI.
4.4.3.4 Military Usage
As discussed in Section 4.2.3.4, military activities within the study region are primarily focused
on exercises conducted within five submarine operating areas. All of these areas lie outside of
the alternative site boundaries. Thus, use of an ODMDS site is not expected to interfere with
military activities (Class III).
Alternative Site 3
Alternative Site 3 is located over 10 nmi from the nearest submarine operating area (U2).
Therefore, impacts on military activities related to dredged material disposal at Alternative Site
3 are considered to be Class HI.
Alternative Site 4
Alternative Site 4 also is located over 10 nmi from the nearest submarine operating area (U5).
Similar to Alternative Site 3, impacts of disposal operations on military activities are considered
to be Class HI.
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4.4.3.5 Recreational Activities
Most of the recreational activities (sailing, whale watching, and fishing) within the study region
occur around the Farallon Islands (see Section 4.2.3.5). Such activities are infrequent within any
of the alternative sites. In addition, the restriction of dredged material barges to specified traffic
lanes would ensure that interferences between barges and recreational users of the Farallon
Islands will be minimized. Thus, potential disposal impacts on recreational activities are
considered negligible (Class IE).
Alternative Site 3
Alternative Site 3 is located over 20 nmi from the Farallon Islands. Therefore, as noted above,
potential disposal impacts on recreational activities are considered to be Class HI.
Alternative Site 4
Alternative Site 4 is located over 30 nmi from the Farallon Islands. Thus, similar to Alternative
Site 3, potential impacts are classified as Class IE.
4.4.3.6 Cultural and Historical Resources
No known cultural or historical resources exist within the alternative sites. Wildlife and
naturalist tours are concentrated around the Farallon Islands and Cordell Bank (at least 20 nmi
from the alternative sites). Therefore, potential impacts should be limited to possible navigational
conflicts between dredged material barges and naturalist vessels. However, these conflicts can
be mitigated by specification of barge traffic lanes that avoid the Farallon Islands region, thus
representing a Class IE impact.
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Alternative Site 3
Alternative Site 3 is located over 20 nmi from the Farallon Islands. Therefore, potential disposal
impacts on cultural and historical resources are considered insignificant (Class HI).
Alternative Site 4
Alternative Site 4 is located over 30 nmi from the Farallon Islands. Thus, similar to Alternative
Site 3, potential disposal impacts are considered insignificant (Class III).
4.4.3.7 Public Health and Welfare
As discussed in Section 4.2.3.7, disposal impacts on public health and welfare are associated with
the potential for interferences between dredged material barges and commercial and recreational
vessels. The potential for such events is considered to be insignificant because navigational
interferences can be minimized by specifying that barge transit lanes and the overall increase in
vessel traffic is considered negligible (Section 4.2.3.7) (Class III).
Alternative Site 3
The potential for vessel interferences at Alternative Site 3 is expected to be negligible, as
discussed above. Therefore, potential impacts from disposal are considered to be Class III.
Alternative Site 4
Similar to Alternative Site 3, the potential for vessel interferences at Alternative Site 4 also is
expected to be insignificant. Therefore, potential impacts from disposal also is considered to be
Class III.
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4.5 Other Alternatives
The environmental consequences associated with other general dredged material disposal options,
such as disposal at sites within the Bay, disposal at nonaqiiatic sites, or treatment/reuse, are being
evaluated by the LTMS In-Bay, Nonaquatic/Reuse, and Implementation Work Groups.
Therefore, detailed evaluations and comparisons of the potential impacts associated with these
options are not addressed by this EIS. The specific environmental consequences of each of the
alternative disposal options will be evaluated, relative to the potential impacts from use of the
ODMDS, during the assessment of permit applications for individual dredging projects.
4.6 Management of the Disposal Site
The primary goal of site management is to assure that the continued use of the disposal site will
not cause significant adverse impacts on the marine environment. Site management is
accomplished, in part, through the evaluation of ocean dumping permit applications and the
development and implementation of a Site Management and Monitoring Plan. Ocean dumping
permits and site management and monitoring are discussed in the following sections. The
objectives of a proposed Site Management and Monitoring Plan will be issued as an appendix
to the Final EIS.
4.6.1 Ocean Dumping Permits
Permits are required for dredging projects which propose to use an ODMDS (except for COE
projects that do not require permits but require EPA approval). In general, the permit application
must demonstrate the need, other than for short-term economic reasons, to use the ODMDS.
Ocean disposal is permitable only if there are no practical alternatives. Some of the factors
evaluated in this process are the environmental risks, impacts, and costs of ocean disposal
compared to those of other feasible alternatives. Therefore, permit applications may be required
to contain the following information:
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• Written documentation of the need to dispose dredged material in the ocean;
• A description of historical dredging and activities at or adjacent to the
proposed dredging site that may represent sources of contamination to the site;
• The type and quantity of the dredged material proposed for disposal at the
ODMDS;
• The existing condition of the proposed dredging area, including the proposed
dredging depths, overdredge depths, and depths adjacent to the boundary of the
proposed dredging area;
• Composition and characteristics of the proposed dredged material, including
the results from physical, chemical, and biological testing. These data will be
used to determine whether the proposed dredged material is suitable for
disposal at the ODMDS; An estimate of the planned start and completion dates
for the dredging operation; this information is needed to avoid potential
resource conflicts and may be used to schedule inspections at the dredging site
and/or the disposal site;
• A debris management plan that addresses the disposal of materials other than
the dredged sediment (e.g., pilings or metal debris) to ensure that these other
materials are not discharged at the ODMDS.
The need for ocean disposal is demonstrated when other, feasible alternatives have been
evaluated, and no practicable alternative locations, methods of disposal, or treatment technologies
exist to reduce adverse impacts from disposal.
The suitability of dredged material proposed for disposal at the ODMDS must be demonstrated
through appropriate physical, chemical, and biological testing according to the requirements and
procedures defined in EPA's Ocean Dumping Regulations (40 CFR Parts 220, 225, 227, and
228). Section 227.6 of the Ocean Dumping Regulations prohibits the disposal of certain
contaminants as other than trace chemical constituents of dredged material. Regulatory decisions
rely on assessments of the potential for unacceptable adverse impacts based on persistence,
toxicity, and bioaccumulation of the constituents, instead of specific numerical limits (EPA/COE
1991).
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The present technical guidance for determining the suitability of dredged material involves a
tiered-testing procedure (EPA/COE 1991). This procedure includes four levels of testing: Tiers I
and n apply existing or easily obtained information and limited chemical testing to predict
effects. If these predictions indicate that the dredged material has any potential for significant
adverse effects, higher tiers are activated. Tiers HI and IV utilize water column and benthic
bioassay and bioaccumulation tests to determine effects on representative marine organisms.
Management decisions concerning the use of the ODMDS in lieu of disposal sites within the Bay,
at nonaquatic sites, or other, approved treatment/reuse options, will be made according to
guidance presently being developed by the LTMS. Decisions regarding the suitability of dredged
material for ocean disposal will be guided by criteria contained in MPRSA and EPA's Ocean
Dumping Criteria (40 CFR Parts 220, 225, 227, and 228). MPRSA authorizes the COE to
administer the permit program for dredged material. The COE, San Francisco District will
prepare the Public Notice concerning the proposed disposal operation, and EPA Region IX as
well as other Federal and State agencies, will participate in the review of the application. EPA
Region IX, will approve, disapprove, and propose conditions on a draft of the MPRSA
Section 103 permit as specified in 40 CFR section 220.4(c). EPA Region IX will not approve
the ocean disposal of material which has the potential for significant adverse biological impacts.
Dumping permits subsequently issued for individual dredging projects may impose additional
conditions on the disposal operations to preclude or minimize potential interferences with other
activities and/or uses of the ocean. Management options for the permitting process may include:
full or partial approval of dredged material proposed for ocean disposal; limits on disposal
volumes; seasonal restrictions (see Section 3.1.2); disposal within a spatially-limited portion of
the disposal site; or requirements, for example, for dredged material barge operators to stay
within specified transit paths, utilize navigation equipment with specified accuracy, and maintain
appropriate ship logs.
Measures to ensure that disposal occurs reliably within the boundaries of the designated ODMDS
are being developed jointly by EPA Region IX and the COE for incorporation into disposal
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permits. Two conditions now being considered are: (1) use of a precision navigation system to
ensure accurate positioning of the disposal barge, together with formal certification of the
accuracy of the on-board equipment; and (2) a requirement for continuous plotting of vessel paths
once inside the central disposal zone, with plots of all disposal trips submitted to and maintained
by the COE for later inspection. EPA Region DC will work with the COE, San Francisco District
and the U.S. Coast Guard to inspect, monitor, and conduct surveillance of disposal operations in
the San Francisco area. If violations of the permit(s) are detected, EPA Region IX may take
appropriate enforcement actions.
4.6.2 Site Management and Monitoring
Site management is the joint responsibility of EPA and COE. Site management actions could
include restrictions on the location, time, rate or method of disposal, restrictions on the
composition and quantity of material to be disposed of, modification of site boundaries, or
de-designation of the site.
The primary purpose of the monitoring program will be to evaluate the impact of disposal on the
marine environment. The goal of site monitoring may include assessment of the following:
The potential for movement of material into estuaries or marine sanctuaries,
onto beaches or shorelines, or toward geographically-limited fishery or
shellfishery areas.
Significant, progressive changes in sediment accumulation outside the disposal
site, to determine whether these changes are attributable to material disposed
at the site.
Significant accumulation of dredged material contaminants in marine biota
near the site.
Significant changes in benthic biological resources as a result of dredged
material disposal at the site.
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EPA and the LTMS Ocean Studies Work Group will develop a monitoring program to detect and
minimize significant adverse impacts. The determination of positive or negative impacts will be
based on an evaluation of data collected as part of the monitoring program.
Specific questions to be addressed by the monitoring program will be based on outstanding issues
and concerns in the site designation process. For example, these questions may include:
• Is the area affected by disposal of dredged material restricted to the disposal
site? (Impacts may be measured by changes in grain size, sediment chemistry,
and biological communities, including benthic invertebrates and fish).
• Does the model used to simulate the dispersal of dredged material accurately
predict movement of material through the water column and to the bottom?
• Is there significant bioaccumulation of chemical contaminants in local
organisms at the site?
• Do disposal operations have a significant impact on biological resources?
• Do disposal operations have a significant impact on the distribution or feeding
habits of seabirds or mammals?
Site management action, such as disposal volume or timing restrictions, will be initiated if
monitoring data indicate nonconformance with permit conditions or if disposal activities have
caused any of the following conditions:
Significant accumulation of waste constituents at or within any shoreline,
marine sanctuary, or critical area;
Biota, sediments, or the water column are adversely affected to the extent that
there are significant decreases in populations of valuable commercial or
recreational species, or in other species essential to the propagation of such
species;
Significant adverse effects to populations of seabirds or marine mammals,
including threatened and endangered species of limited distribution;
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Material has accumulated to the extent that major uses of the site are impaired;
Adverse effects to the taste or odor of valuable commercial or recreational
species; or
Dredged material is identified consistently in toxic concentrations outside the
disposal site more than 4 hours after disposal [40 CFR 228.10 (c)(l)(i)-(v)].
4.7 Cumulative Impacts as a Result of the Project
Ongoing and historical discharges in the LTMS study region are described in Sections 1.7 and
3.1.1. These discharges include disposal of dredged material at the Channel Bar ODMDS
(5.6 km from shore) and discharges of treated wastewaters from several coastal outfalls, including
San Francisco Southwest Ocean Outfall (10.2 km from shore), City of Pacifica Outfall (0.8 km
from shore), and Northern San Mateo County Outfall (0.8 km from shore). Additional dredged
material disposal activities also may occur near or within Alternative Site 5 as part of an MPRS A
Section 103 Permit requested by the Navy. Discontinued historical waste discharges in the
LTMS study region include dredged material disposal, acid waste, cannery waste, low-level
radioactive waste, munitions, refinery waste, and vessel and dry dock disposal (Figure 3.1-1).
Due to the large distances (greater than 45 nmi) from shore to the alternative sites, discharges
of treated wastewaters from nearshore outfalls are unlikely to cause any cumulative effects with
regard to designation or use of an offshore ODMDS. Ocean disposal of acid waste, cannery
waste, and refinery waste was discontinued approximately 20 years ago (in 1971-1972), and the
presence of residual wastes which could interact with discharged dredged material to produce
cumulative, adverse, environmental effects has not been detected (Section 3.2.5). Similarly, the
majority of the dredged material disposal activities were discontinued 14 to 25 years ago (BART
in 1967, COE Test Site in 1974, and the 100-Fathom Site in 1978,). Present dredged material
disposal activities at the Channel Bar ODMDS are too far (approximately 45 to 55 nmi) from the
alternative sites to produce cumulative effects. Also, the sandy material from the entrance
channel discharged at the site is not expected to contain chemical contaminants which could
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contribute to cumulative effects. In contrast, other discharge activities discussed below may have
some effect on the proposed actions due to the proximity of these historical discharge operations
to one or more of the alternative sites and the likelihood of residual contamination.
4.7.1 Radioactive Waste Disposal Sites
One of three radioactive waste sites (Site B in 1,800 m of water) is located in the vicinity of
Study Area 5 (Figure 3.1-1). The other two sites (Site A at 90 m depth and C at 900 m depth)
are within the GOFNMS and located approximately 20 nmi or more from the alternative sites.
However, the precise locations of the majority of the waste containers are unknown, and the
wastes may be spread over a large area within the general region. All known disposal of
containerized, low-level radioactive wastes at Sites A, B, and C was suspended by 1965. Due
to the expected residual radioactivity associated with this waste, some potential exists for
contamination of bottom sediments and organisms. The magnitude of the contamination, and
potential risks to environmental resources and human health, presently are being evaluated by
NOAA and EPA.
It is unlikely that dredged material disposal would cause cumulative effects in conjunction with
these low-level radioactive waste containers. In fact, deposition of dredged material could have
the effect of burying and further isolating some containers. However, it would not be practical
at this time to use dredged material specifically for burying waste containers because, according
to best available information, most of the containers are close to the Farallon Islands and within
the GOFNMS. The primary concern related to ODMDS designation is the potential for
accidental recovery of radioactive waste material during baseline and monitoring surveys of the
ODMDS. Inadvertent collection of some radioactive material has occurred in the southeastern
portion of Study Area 5, but outside of Alternative Site 5 (Lissner, SAIC, pers. obs. 1992).
Therefore, while cumulative effects are not a significant concern, it is important to address the
feasibility of monitoring an ODMDS situated in the vicinity of the radioactive waste disposal
sites.
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4.7.2 Munitions Waste Sites
The Chemical Munitions Dumping Area (CMDA) is located within Study Area 5 (Figure 3.1-1).
Two other disused munitions disposal areas are adjacent to Study Area 4. As with the
radioactive waste sites, disposal operations at the munitions waste disposal sites were terminated
over 20 years ago (by 1969). The potential exists for regional environmental contamination
and/or human health concerns from historically disposed chemical agents and explosives.
However, cumulative impacts from dredged material disposal are unlikely, and deposition of
dredged material could bury some munitions. The primary concern associated with designation
of an ODMDS would be accidental recovery of munitions wastes during baseline or monitoring
surveys of the ODMDS. Inadvertent collection of munitions near Alternative Site 5 has occurred
(Lissner, SAIC, pers. obs. 1992). Thus, while cumulative impacts are not considered significant,
it is important to evaluate the feasibility of monitoring an ODMDS which lies in vicinity of the
historical munitions disposal sites.
4.7.3 Navy Section 103 Dredged Material Disposal
The Navy currently is conducting studies in support of an MPRSA Section 103 interim site
designation for the Naval Ocean Disposal Site (NODS), which corresponds approximately to
Alternative Site 5. If granted, the dredged material disposed at the site could contribute to
cumulative effects associated with any subsequent use of the site for other dredged material
disposal operations. As required under MPRSA, any dredged material, whether disposed of at
a Section 102 or a Section 103 site, must meet all applicable criteria to be eligible for ocean
disposal. Assessment of any cumulative effects will be part of the site monitoring plan. Data
collected by the Navy, required as part of their monitoring program as specified in a Section 103
permit, could be used to assess cumulative effects from subsequent disposal operations at
Alternative Site 5.
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4.7.4 BIB Dredged Material Disposal Site
The BIB site is located within the boundary of LTMS Study Area 2 (Figure 3.1-1). The site was
used briefly in 1988 for disposal of approximately 18,000 yd3 of dredged material from the Port
of Oakland. In general, this volume of material is very small, and residual effects at the site,
including cumulative effects related to the proposed action, are unknown. Results from recent
EPA surveys (SAIC 1992b,c) indicate that the shelf area is a high-energy zone and fine-grained
material appears readily dispersed (Noble and Ramp 1992; SAIC 1992c). Therefore, detectable
quantities of dredged material from the Port of Oakland may no longer exist in the vicinity of
the BIB site.
4.8 Relationship Between Short-Term Use and Long-Term Resource Uses
The proposed designation of any of the alternative sites as an ODMDS is not expected to produce
significant, long-term, adverse impacts to resources, including the physical, biological, and
socioeconomic environments, within the LTMS study region. Impacts to benthic invertebrates
within the site are expected to persist as long as the site is used for disposal. However, cessation
of disposal should result in gradual recovery over time. Deep sites generally are expected to
require longer recovery times than shallow-water sites due to the slow rates of change that
typically are associated with more stable conditions (Sanders and Hessler 1969).
Use of the proposed ODMDS is not expected to interfere with uses of resources outside of the
boundaries of the alternative sites. These resources include commercial and sport fishing, seabird
and mammal observation, and use of the region by commercial, military, and recreational vessels
(Sections 3.4 and 4.4). No significant mineral or oil and gas resources occur within any of the
alternative sites (Sections 3.4 and 4.4). Therefore, use of ODMDS does not represent a potential
conflict with the long-term use of resources.
Any impacts or restricted uses of resources within the site boundaries would represent a very
small percentage of these resources within the LTMS study region. This marginal loss of some
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resources is balanced by the significant benefit that would be derived from the proposed action.
In contrast, lack of a designated ocean, disposal site capable of receiving large quantities of
dredged material could have a significant adverse effect on the economic productivity and
national defense activities associated with San Francisco Bay (COE 1990a,b, 1991).
4.9 Irreversible or Irretrievable Commitment of Resources
Irreversible or irretrievable resources that would be committed if an ocean disposal site is
designated will include:
Energy resources used as fuel for dredges, pumps, and disposal vessels, and
for research vessels involved in any subsequent monitoring studies;
Economic resources associated with ocean disposal including monitoring and
surveillance;
Unavailability of sediments disposed at the ODMDS for potential marsh
restoration or other beneficial use projects; and
Some loss or degradation of the benthic habitat and associated benthic
communities at the site for at least the duration of site use.
The commitment of energy and economic resources will increase with increased distance of a site
from dredging areas. However, the three alternative sites are similar distances from the Golden
Gate Bridge, and no significant differences in the resources contained within the alternative sites
are evident Therefore, the magnitude of any long-term commitment of irreversible or
irretrievable resources that can be determined from the existing information is essentially the
same for each of the three alternative sites.
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CHAPTER 5
COORDINATION
This chapter contains information on public involvement and interagency activities related to the
Draft Environmental Impact Statement (DEIS) for designation of the San Francisco Deep Water
Ocean Dredged Material Disposal Site (Sections 5.1 and 5.2, respectively); evidence of formal
consultation (Section 5.3); and requested reviewers and public distribution of the DEIS
(Sections 5.4 and 5.5, respectively).
5.1 Notice of Intent and Public Scoping Meeting
The Notice of Intent (NOI) to prepare an environmental impact statement related to designation
of an ocean dredged material disposal site (ODMDS) was published in the Federal Register on
March 31, 1989 (Exhibit 1).
A public scoping meeting was held in Sausalito, California on April 11, 1989 to identify affected
public and agency concerns and to define the issues and alternatives to be examined in detail in
the EIS. At this scoping meeting, EPA explained the need for and process of site designation
and identified several geographic areas for further evaluation. These areas included the
continental shelf to a depth of 100 fathoms (183 m), the shelf break from 100 to 300 fathoms
(183 to 550 m), the continental slope from 300 to 500 fathoms (550 to 914 m), the deep slope
area from 500 to 1,000 fathoms (914 to 1,829 m), Pioneer Canyon from 300 to 1,000 fathoms
(550 to 1,829 m), and areas deeper than 1,000 fathoms (1,829 m).
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EXHIBIT 1
Federal Register / VaL 54. No. SI / Friday. March 31. .1989 / Notices
.... ...-13233
(ER-FRL-3549-3]
Designation «f an Ocean Dredged
Material Disposal Srte (ODMDS) off San
Francisco, (iA; Intention To Prepare an
Environmental Impact Statement
AGENCY: US. Environmental Protection
Agency (EPA), Region 9-
ACnotc Notice of Intent to prepare an
Environmental Impact Statement (EIS)
on the designation of an ODMDS off San
Francisco, California.
Purpose The US. EPA. Region 9. in
accordance with section 10Z(2)(c) of the
National Environmental Policy Act
(NEPA) and in cooperation, with the San
Francisra District of the IXS. Army
Corps of Engineers, will prepare a Draft-
: EIS (DEIS) on the designation of an
ODMDS for dredged matenaTpff San
Francisco. California. An EIS is needed-
tO provide the infofyra Hmi . ifarjuuurry to
; designate a
-Intent isissued pursuant to Section 102
, of ths Marine Protection. Research and
, Sanctuaries Act (MPRSA) of 1S72, and •
Management of Disposal Sites for Ocean
•'• Damping).
-• . FozFariher Information aid to be .;
-. Placet! da the MaSny List Contact:.
. Section (W-7-1), U3. Environmental
:P»tection Agency. Region 9/215 'S!
"
94105, telephone number (415)
974-02S7, or FTS 454-0257.
. SUHHAHT: Designation of the San .• . . , .:
Francisco ODMDS Is needed to provide ;
.Bay and other locations in fee 'vicinity. •
Disposal of dredged nmhmiil at any
ODMDS is not permitted unless EPA
flnn tnff uOTpS riffii^wmnji tnftt Ttift • _
al tend
EPA's Ocean Dumping criteria at 40 CFR
225 and 40 CFR 227. The Corps issneff*
^inriiiii« under Section 103 of MPRSA.-
snbject to EPA review, :; .; '..•'•
EPA and the Corps are evaluating . '
sevEtal geographical areas for suitable . . •
disposal, sites. These geographical areas
include continental shelf to A depth of •
100 fathoms (fin], the shelf break from
100—300 fa\ the continental slope 300— '
500 fin, the deep slope ana 500-1000 fin,-
. Pioneer Canyon SCO-'UJOO fin. and areas
deeper than UXX) fin. . - : - • -
The Corps will completB "11" •
l anO ^^CTYQtnl^ StUQI6S ',
related to the San Francisco site in
snppprt of EIS preparation. EPA is
responsible for reviewing the ... ......
information used in preparation of the
hing *h^ docaneoL.loe •
Corps win assist EPA in responding to .
any comments recervad on the DEIS and
subsequent site desination "
Neeti for Action: Tie Corps of -. •
Engineers, San Francisco District has
requested that JSPA designate aa
ODMDS off shore of San Francisco,
California. An EIS is required to provide
the necessary information to evaluate
disposal alternatives and to designate
the preferred ODMDS. If the proposed
dredged material from San Francisco
Bay and other locations in the vicinity
meets the criteria for r»-j»an disposal at
40 CFR Parts 225 and 227 then the
material may be disposed at the
designated site.
• „• Altemativeslhe EIS win
: characterize «initi'H'H'i*Mfal parameters.
•• evaluate a reasonable range of. -
alternatives to determine whether '.. i
: designation of ail ocean disposal site is
acceptablei--T&e altematives.iicliide (l)
No Action;!?) Existing In-Bay Disposal.
Sites, (3) NewIrfrBay Disposal Sites. (4)
) Historical Ocean:-
") Ocean Disposal
ocal areas.
conversion of San Diego's wastewater
treatment facilities from advanced -•
priiimry trealimml to secondary : •-
treatment and waterreclamatioa.
Pmpose: In accordance with section
511(c) of fee dean Water Act (CWA)
and section I02(2)(c) of the National
Envrranmental Policy Act (NEPA], EPA
has identified a need to prepare an EIS
and therefore issues this Amended
Notice of Intent
ForFartberlnfixnnGtian and to be
Placed on the Project MaEing List
Contact Mr. Krrin Sebastian!
Construction Grants Branch. U.S. EPA.
(W-2-2), 215 Fremont St. San Francisco,
CA 94105, Telephone: (Conuaercjaji ilo-
574-8316 or (FTS) 453-8316.
Ciiy of Ssn Diego has
initialed a new program; the Clean ;
Water Program for Greater San Bieso,
with a goal of attaining fhll conndiaDce':
with the CWA and NEPA; The "program
is correnuy m the faafities'planBing . "
stage. The/resulting plan will.
lecbramehdboth secondary treatment
•' and water reclamation facilltJSS" of
described above.
,v.Sa^Łi^ Preliminary scoping meetings
•were held onrTeiuiBry. 18,1989.and:.
. rVBMM^. «._ J ^1 '-.-^ V :~ •*T*^w'
. ^ of'
• the twenry^Brst\cKntirry;Facili4i.es .
— — 'J «^"^i-*— -' an:
scoping meetings for fce'general'pnbHc'
are schednleil on'Aprilil, 1989, from .
. wastejTOter'.treatmenfplant. ore ot tivo:
-other secijndary ^treatment plante,.a .1-5
" nmnberof "wateiecl'
-p^Tlie'meerlngswinbeheldatthe ..
Bay Motel. 2100 aidgeway; Sausaltto,
CaMnnia. 94965. Written comments on
this. Notice 'of Intent should be seat to
the contact person listed above no later
than 45 days after the date of .- '
poblicatioii. '•••'"'•'. ' •' ' .
Estiisated Date o/JZefeoserThe DEIS
will be made available in Match 199L
..Responsible Ofiidal: • . .
. shidge handling and disposal facilities; '
ofts and
Date: March 28. 1933.
J7.irei*&7& OjJJGff OfffGOCroIAuLi viiies*
[PR Doae3-774ZF3ed 3-30-89: ass am]
[EH-FRL 3543-1] '
Intention To Prepare a Draft . .
HDvlromn^fltftl uopsct otfltonioiit (ciS)Ł
C8y of San Dfegtf Wastewater
Treatment FacffiBes, CaBfomia
• AGENCVS U5- Euvifojundtal Protection
Agency |EPA) Region DC.
ACncmr Preparation of a Draft
Environmental Impact Statement on the
.
Needfbr Action: On September. 30,
1388. EPA-annoanced its decision to
tentatively deny fee City of San Diego's
1979 and 1985 applications for a waiver
under Section 301(h) of the CWA. On
November i 1888, fee City CoancO.
authorized .Che (Sty Manager to send
EPA a letter of intent to file a revised
waiver appncation. On Febrnary 17. - -
1987, the City Connca decided to ..... .-
discontmue wahrer efforts and to pnrsne
secoDdary treatment •• •* ' ";. '•
" Alternatives: Six alternatrves pins die
No Project alternative are presently
under consideration for providing
secondary treatment in the San Diego
area.-The alternatives involve variations
in the aze aid-extent of treatment . .
fecmfies in me North CSry area, at the
existing Point Loma treatment site, at
locations near Ijndbergh Field, and at
sites along the US./ Mexico border.
Alternathre sites ate also being :
considered for a nnmber of reclamation
plants throughout the San Diego
metropolitan area.
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Comments made during the scoping meeting covered the following general topics:
Proximity of the ocean disposal site to the Gulf of the Farallones National
Marine Sanctuary, Cordell Bank National Marine Sanctuary, hard-bottom
areas, and Pioneer Canyon;
Potential interferences with existing and/or future fishery resources, and
feeding, breeding, and migratory activities of marine birds and mammals;
Potential impacts to other water column organisms should dredged material
particles remain suspended;
Potential problems predicting the area affected by disposal operations; and
Potential problems monitoring short- and long-term effects from disposal
operations at a deep-water site.
5.2 San Francisco Bay Long-Term Management Strategy for Dredged Material
The Long-Term Management Strategy (LTMS) program began in January 1990 as a Federal/State
partnership between the four agencies which have regulatory authority for dredged material in
the San Francisco Bay area. The LTMS is designed to provide a regional plan for the disposal
of up to 400 million yd3 of dredged materials from the San Francisco Bay over the next 50 years.
As the lead agencies for the LTMS, the U.S. Army Corps of Engineers (COE), the Environmental
Protection Agency Region DC (EPA), the San Francisco Bay Regional Water Quality Control
Board (SFBRWQCB), and the San Francisco Bay Conservation and Development Commission
(BCDC), share responsibility for managing the various components of the LTMS.
Within the LTMS structure are several committees (Figure 5.2-1). The Executive Committee is
composed of the COE South Pacific Division Commander, the EPA Regional Administrator, the
SFBRWQCB Chairperson, the BCDC Chairperson, and a state coordinator. This committee
provides management and policy guidance and retains principal decision-making authority for
LTMS program issues. However, overall LTMS coordination and technical direction is delegated
to the Management Committee. This committee, consisting of the COE South Pacific Division
5-3
-------
EXECUTIVE COMMITTEE
Commander SPD
RA EPA Region IX
Chairman, RWQCB
Chairman, BCOC
Secretary, Cal EPA
POLICY REVIEW COMM.
Regulatory Agencies Ports,
Development & Environmental
Interests
TECH. REVIEW PANEL
MANAGEMENT COMMITTEE
Dist. Eng., SFD
Oir. WMD, EPA Region IX
Exec. Off.. RWQCB
Exec. Off., BCDC
PUBLIC INVOLVEMENT SFEP
CHAIRS COMMITTEE
1
OCEAN
EPA
IN-BAY
RWQCB
^
NONAQUATIC/REUSE
BCDC
^
IMPLEMENTATION
COE/CAL EPA
Figure 5.2-1 Long-Term Management Strategy (LTMS) Management and
Implementation Structure.
AK01S1
5-4
-------
LTMS Program Manager, the EPA Water Management Division Director, the SFBRWQCB
Executive Officer, and the BCDC Executive Director, oversees the LTMS work groups and the
Technical Review Panel.
There are four LTMS work groups including the Ocean Studies Work Group (OSWG), the In-
Bay Work Group, the Nonaquatic/Reuse Work Group, and the Implementation Work Group.
Each of these work groups has its own structure, public involvement strategy, and specific
objectives. The Ocean, In-Bay, and Nonaquatic/Reuse Work Groups are responsible for
conducting the tasks described in the LTMS Study Plan (COE 1991). The Implementation Work
Group is the newest of the work groups. The Steering Committee of this work group has
recently proposed a series of subcommittees to deal with the issues of siting framework, sediment
quality, financing and ownership, containment sites, a programmatic management document, and
project coordination.
The Technical Review Panel is composed of five scientific experts who provide critical reviews
of technical issues that lie outside of the LTMS program's broad conceptual approach. The
members of the Technical Review Panel are shown in Table 5.2-1.
The LTMS structure also includes an advisory group, the Policy Review Committee, which is
comprised of a broad range of Federal and State agencies, ports, development, environmental,
and fishing interests (Table 5.2-2). This committee meets quarterly and provides an important
forum for public involvement in, and review of, LTMS development and implementation.
Another mechanism for public involvement in the LTMS is the San Francisco Estuary Project,
which serves to disseminate information to the general public through its outreach programs.
5.3 LTMS Ocean Studies Work Group
The LTMS OSWG, led by EPA, meets periodically to allow EPA and others to present
preliminary or final study findings and to solicit comments from group members. The members
of the OWSG, commentors on OSWG products, and attendees of the OSWG meetings are shown
5-5
-------
Table 5.2-1. Members of the LTMS Technical Review Panel.
Name
Don F. Boesch
R. Risebrough
Hsieh W. Shen
Tom Ginn
David R. Stoddart
Specialty
Benthic Community Analysis
Chemistry
Physical Processes
Sediment Toxicology
Wetland Geomorphology
Organization
University of Maryland
University of California — Santa Cruz
University of California — Berkeley
PTI, Inc.
University of California — Berkeley
AK0148.W51
5-6
-------
Table 5.2-2. Members of the LTMS Policy Review Committee
Category
Member Organization
Federal Agencies
Gulf of the Farallones National Marine Sanctuary
National Marine Fisheries Service
National Oceanic and Atmospheric Administration
U.S. Army Corps of Engineers
U.S. Coast Guard
U.S. Environmental Protection Agency
U.S. Fish and Wildlife Service
U.S. Geological Survey
U.S. Navy
California State and Regional
Agencies
Coastal Commission
Department of Boating and Waterways
Department of Fish and Game
Department of Water Resources
Integrated Waste Management Board
San Francisco Bay Conservation and Development Commission
Secretary for Environmental Protection
Secretary of Business, Transportation, and Housing
State Lands Commission
State Water Resources Control Board
The Resources Agency
Special Interest Groups
Bay Planning Coalition
California Marine Affairs and Navigation Conference
Citizens for a Better Environment
Golden Gate Ports Association
Half Moon Bay Fisherman's Marketing Association
Ocean Alliance
Pacific Coast Federation of Fisherman's Associations
Port of Oakland
Port of Redwood City
Port of Richmond
Port of San Francisco
Save San Francisco Bay Association
Sierra Club
United Anglers of California
AK0149.W51
5-7
-------
in Tables 5.3-1, 5.3-2, and 5.3-3, respectively. Under the LTMS program, EPA first convened
representatives of interested agencies and groups on February 20, 1990, to present an outline of
the LTMS Ocean Studies Plan (OSP). The purpose of this document was to define objectives
and identify studies necessary to address the site selection general and specific criteria (see Table
1.1-1). At a meeting of the LTMS Policy Review Committee on February 27, 1990, interested
reviewers were asked to submit comments on the OSP outline.
Using comments received at the February 1990 meeting and written comments from members
of the Policy Review Committee, EPA prepared a response to comments and developed the OSP
outline into a detailed plan. This draft OSP was presented and distributed to the Ocean Studies
Work Group at its first official meeting on November 8, 1990. At this meeting, attendees were
asked to submit comments on the draft OSP by early December. EPA prepared responses to
comments and presented those responses at another OSWG meeting held December 17, 1990.
Since one of the major issues for the site designation process was the methodology used in
assessing fish communities, EPA convened a special work group meeting at NMFS (Tiburon) on
January 8, 1991 to discuss these issues. Afterward, another OSWG meeting was held on
February 20, 1991. At this meeting, the COE presented a draft Zone of Siting Feasibility
determination which included all of the study areas identified by EPA in the draft OSP. Other
topics discussed at this meeting included preliminary footprint modeling and proposed changes
to the OSP based on comments received at the previous two meetings.
EPA released a draft final OSP on March 8, 1991. This document contained a detailed
description of each of the site selection criteria and defined specific objectives for four study
elements: Physical Oceanography, Benthic Infauna and Sediments, Epifauna and Fisheries, and
Marine Birds and Mammals. In addition, the document provided an assessment of existing
information for the study areas, a description of specific studies to be conducted, and a cost
estimate. EPA received written comments on the draft final OSP and revised it into a final OSP
which was released at a Policy Review Committee meeting on June 7, 1991.
5-8
-------
Table 5.3-1. LTMS Ocean Studies Work Group (OSWG) Members.
Members listed alphabetically by affiliation.
Name
Bill Boland
Tom low
Ellen Johnck
Mark Delaplaine
Jim Raives
George Armstrong
Pete Phillips
Robert Tasto
Tracy Wood
Mary Bergen
Alan Ramo
Kathleen van Velsor
Marie White
Jeffrey Cox
Jan Roletto
Ed Ueber
Pietro Parravano
Cynthia Koehler
Robert Battalio
Greg Cailliet
James Nybakken
Herb Curl
Alec MacCall
Chris Mobley
Don Pearson
Gail Blaise
Lynelle Johnson
Catherine Courtney
David Cobb
Organization
independent
independent
Bay Planning Coalition
California Coastal Commission
California Coastal Commission
California Department of Boating and Waterways
California Department of Fish and Game
California Department of Fish and Game
California Integrated Waste Management Board
California State Lands Commission
Citizens for a Better Environment
Coastal Advocates
Entrix
Evans-Hamilton, Inc.
Gulf of the Farallones National Marine Sanctuary
Gulf of the Farallones National Marine Sanctuary
Half Moon Bay Fisherman's Association
Heller, Ehrman, White and McAuliffe
Moffatt and Nichol
Moss Landing Marine Laboratories
Moss Landing Marine Laboratories
National Oceanic and Aeronautical Administration Hazardous Materials
National Marine Fisheries Service
National Marine Fisheries Service
National Marine Fisheries Service
Office of Congresswoman Barbara Boxer
Office of Congressman George Miller
PRC Environmental Management Inc.
PTI Environmental Services
AK0169.W51
5-9
-------
Table 5.3-1. Continued.
Name
Zeke Grader
David Ainley
Sarah Allen
Jim McGrath
Charles Schwarz
Jody Zaitlin
Steve Goldbeck
Scott Rouillard
Michael Carlin
Paul Jones
Andrew Lissner
John Lunz
David Nesmith
Kim Brown
John Beuttler
Commander Scot Tiernan
Rod Chisholm
Bill McCoy
Lynn O'Leary
Richard Stradford
Tom Wakeman
William Allen
Jean Takakawa
Herman Karl
Marlene Noble
Curt Collins
Steven Ramp
Sherman Seelinger
Organization
Pacific Coast Federation of Fish Association
Point Reyes Bird Observatory
Point Reyes Bird Observatory
Port of Oakland
Port of Oakland
Port of Oakland
San Francisco BCDC
San Francisco Bay Keeper
San Francisco Regional Water Quality Control Board
San Francisco Regional Water Quality Control Board and U.S.
Environmental Protection Agency
Science Applications International Corporation
Science Applications International Corporation
Sierra Club
Tetra Tech
United Anglers of America
U.S. Coast Guard Marine Safety Office
U.S. Corps of Engineers
U.S. Corps of Engineers
U.S. Corps of Engineers
U.S. Corps of Engineers
U.S. Corps of Engineers
U.S. Department of the Interior
U.S. Fish and Wildlife Service
U.S. Geological Survey
U.S. Geological Survey
U.S. Naval Postgraduate School
U.S. Naval Postgraduate School
U.S. Navy Western Division
AK0169.W51
5-10
-------
Table 5.3-2. Agencies and Organizations that Provided Written Comments on LTMS
Ocean Studies Plan, February 1990 to June 1991.
California Coastal Commission
California Department of Fish and Game
California Environmental Protection Agency
Golden Gate Ports Association
Gulf of the Farallones National Marine Sanctuary
Half Moon Bay Fisherman's Marketing Association
National Marine Fisheries Service, Santa Rosa
National Marine Fisheries Service, Tiburon
Point Reyes Bird Observatory
Port of Oakland
San Francisco Bay Conservation and Development Commission
San Francsico Bay Regional Water Quality Control Board
Save San Francisco Bay Association
State Lands Commission
United States Army Corps of Engineers, San Francisco District
United States Army Corps of Engineers, South Pacific Division
United States Army Corps of Engineers, Waterways Experiment Station
United States Coast Guard
United States Environmental Protection Agency, Office of Research and Development
United States Geological Survey
United States Naval Postgraduate School
United States Navy
AK0170.W51
-------
Table 5.3-3. Attendance at LTMS Ocean Studies Work Group Meetings, February 1990 to September 1992.
Organization
Bay Conservation and Development Commission
Bay Planning Coalition
Bill Boland
California Coastal Commission
California Department of Boating and Waterways
California Department of Fish and Game
California Marine Affairs and Navigation
Conference (CMANC)
Citizens for a Better Environment
Coastal Advocates
Congresswoman Boxer's Office
Corps of Engineers
Department of the Interior
Golden Gate Ports Association
Gulf of the Farallones National Marine Sanctuary
Half Moon Bay Fisherman's Marketing Association
Integrated Waste Management Board
Moss Landing Marine Laboratories
National Marine Fisheries Service
National Oceanic and Atmospheric Administration
(NOAA)
Naval Postgraduate School
2/20/90
X
X
X
X
X
X
X
X
11/8/90
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
12/17/90
X
X
X
X
X
X
X
X
X
1/8/91
X
X
X
X
X
2/26/91
X
X
X
X
X
X
7/29/91
X
X
X
X
X
X
X
X
X
X
12/12791
X
X
X
X
X
X
X
X
2/13/92
X
X
X
X
X
X
X
X
5/4/92
X
X
X
X
X
X
X
8/14/92
X
X
X
X
X
X
X
X
X
9/29/92
X
X
X
X
X
X
to
AK0146.W51
-------
Table 5.3-3. Continued.
Organization
Point Reyes Bird Observatory
Port of Oakland
San Francisco Bay Regional Water Quality
Control Board
Sierra Club
State Lands Commission
U.S. Fish and Wildlife Service
U.S. Geological Survey
U.S. Navy
University of California at Davis
2/20/90
X
X
X
X
11/8/90
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
N/A
12/17/90
X
X
X
X
1/8/91
X
X
2/26/91
X
X
X
X
7/29/91
X
X
X
12/12/91
X
X
X
2/13/92
X
X
X
5/4/92
X
8/14/92
X
X
X
X
X
9/29/92
X
X
X
AK0146.W51
-------
Since some commentors felt that the final OSP had not resolved all of the outstanding issues,
EPA prepared responses to comment letters from the Gulf of the Farallones National Marine
Sanctuary and the California Environmental Protection Agency and held an OSWG meeting on
July 29, 1991 to address these issues. Other presentations at this meeting included additional
preliminary footprint modeling and the scope of services for the OSP biological studies.
At the next Ocean Studies Work Group meeting held on December 12, 1991, EPA presented
preliminary results of the benthic infauna and sediments, trawl, and remotely-operated vehicle
studies to the OSWG. Preliminary results of database analyses performed by the National Marine
Fisheries Service and the Point Reyes Bird Observatory under contract to EPA were also
presented. Other topics of discussion included the need for a second season of biological
sampling and the compatibility of EPA field work with studies conducted by the Navy in LTMS
Study Area 5.
In order to address concerns about compatibility between EPA and Navy studies, EPA made the
Navy studies the focus of an OSWG meeting held on February 13, 1992. At this meeting, the
Navy described the types of studies conducted and their preliminary findings. The topic of the
May 4, 1992 OSWG meeting also related to this issue. Since the OSWG was very concerned
about comparison of data collected with different gear types, EPA presented a synopsis of data
types and recommended approaches for analyzing and comparing EPA and Navy data. Following
the recommendation of the OSWG, EPA has avoided quantitative comparisons between certain
data sets.
On August 14, 1992, EPA held another OSWG meeting to present results from each of the OSP
components and to propose alternative sites within the OSP study areas. OSWG members agreed
on the locations of alternative sites and voiced their opinions and concerns regarding the
comparison of these alternative sites to the EPA site selection criteria (40 CFR Sections 228.5
and 228.6). At an OSWG meeting held on September 29, 1992, EPA presented its tentative
selection of Alternate Site 5, within Study Area 5, as the preferred alternative for site designation.
The members of the OSWG who attended the meeting (Table 5.3-1) did not react negatively to
5-14
-------
EPA's selection of Alternative Site 5. While some concerns were raised regarding seabirds and
marine mammals, the balance of information did not lead the OSWG members to call for
selection of another alternative site.
EPA will continue to hold OSWG meetings to address comments on the DEIS, develop the site
management and monitoring plan, and prepare the FEIS and proposed rule.
5.4 Formal Consultation
The Endangered Species Act requires formal consultation with Federal and State agencies to
identify any threatened, endangered, or special status species occurring within the region that may
be affected by the proposed action. The formal consultation process with the U.S. Fish and
Wildlife Service, the National Marine Fisheries Service, and the California Department of Fish
and Game was initiated on July 22, 1992 (Exhibits 2, 3, and 4). Further consultation
documentation, including responses from these agencies and concurrence certification, will be
included in the FEIS.
The National Historic Preservation Act requires consultation with the State Historic Preservation
Officer to identify any areas within the study region of architectural, archeological, historic, or
cultural value that are currently listed or eligible for listing on the National Register of Historic
Places. Coordination with the California State Historic Preservation Officer also was initiated
on July 22, 1992 (Exhibit 5). Further documentation of this consultation will also be included
in the FEIS.
5.5 Public Distribution of the Draft Environmental Impact Statement
The list of agencies, organizations, and individuals to whom the DEIS will be distributed is
shown in Table 5.5-1. A Notice of Availability will be sent to the approximately 1,000 agencies,
companies, and organizations on the Corps of Engineers San Francisco District Environmental
Branch's mailing list Additional copies of the EIS may be requested from EPA or the document
5-15
-------
EXHIBIT 2
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
>BO,fcov REGION IX
75 Hawthorne Street
San Francisco, Ca. 94105-3901
•'82 JUL 1992
Mr. William Lehman
Endangered Species Coordinator
U.S. Fish and Wildlife Service
2800 Cottage Way, Room E-1823
Sacramento, CA 95825
Dear Mr. Lehman:
The Environmental Protection Agency Region IX (EPA) is preparing an
Environmental Impact Statement (EIS) for the designation of an ocean dredged material
disposal site off San Francisco, California. The site will be selected as part of the Long-
Term Management Strategy (LTMS) for San Francisco Bay and will have the capacity to
accomodate an estimated 400 million cubic yards of dredged material over a 50-year period.
The proposed action will involve only the designation of the site itself; before disposal is
permitted, dredged material must be evaluated in accordance with the Marine Protection,
Research and Sanctuaries Act of 1972 and its implementing regulations and guidance.
EPA began the site designation process by evaluating four study areas on the Farallon
Shelf and Slope at distances of 20 to 55 miles offshore and at depths of 300 to 6000 feet.
The four study areas are delineated on the enclosed map (areas 2-5) and coordinate list.
With the recent designation of the Monterey Bay National Marine Sanctuary Study Areas 2
and the eastern third of Study Area 3 are no longer being considered as potential sites.
However, since data have been collected for all four study areas, a characterization of each
area is being developed. In the draft EIS, which is scheduled for release in November
1992, EPA will identify candidate sites within Study Areas 3,4 and 5 and will choose a
preferred alternative site.
In accordance with Section 7(c) of the Endangered Species Act, please advise EPA of
the presence of any listed, or candidate, threatened or endangered species in the vicinity of
the four study areas identified above. In addition, please advise EPA of any critical habitat
for these species which may be impacted by the proposed action. Similar requests have
been forwarded to the National Marine Fisheries Service and the California Department of
Fish and Game. EPA would appreciate your response prior to October 1,1992. Please
direct any questions or requests for further information to Shelley Clarke at (415) 744-
1162.
Sincerely,
— - - — — - —• ~ j i i i
J . y/ / • L
^^'(^a-^y^j. V?W'Łruyr
-------
EXHIBIT 3
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, Ca. 94105-3901
JUL1992
Mr. James Bybee
Environmental Coordinator, Northern Area
National Marine Fisheries Service
777 Sonoma Avenue, Room 325
Santa Rosa, CA 95404
Dear Mr. Bybee:
The Environmental Protection Agency Region IX (EPA) is preparing an
Environmental Impact Statement (EIS) for die designation of an ocean dredged material
disposal site off San Francisco, California. The site will be selected as part of the Long-
Term Management Strategy (LTMS) for San Francisco Bay and will have the capacity to
accomodate an estimated 400 million cubic yards of dredged material over a 50-year period.
The proposed action will involve only the designation of the site itself; before disposal is
permitted, dredged material must be evaluated in accordance with the Marine Protection,
Research and Sanctuaries Act of 1972 and its implementing regulations and guidance.
EPA began the site designation process by evaluating four study areas on the Farallon
Shelf and Slope at distances of 20 to 55 miles offshore and at depths of 300 to 6000 feet.
The four study areas arc delineated on the enclosed map (areas 2-5) and coordinate list
With the recent designation of the Monterey Bay National Marine Sanctuary Study Areas 2
and the eastern third of Study Area 3 are no longer being considered as potential sites.
However, since data have been collected for all four study areas, a characterization of each
area is being developed. In the draft EIS, which is scheduled for release in November
1992, EPA will identify candidate sites within Study Areas 3,4 and 5 and will choose a
preferred alternative site.
In accordance with Section 7(c) of the Endangered Species Act, please advise EPA of
the presence of any listed, or candidate, threatened or endangered species in the vicinity of
the four study areas identified above. In addition, please advise EPA of any critical habitat
for these species which may be impacted by the proposed action. Similar requests have
been forwarded to the U.S. Fish and Wildlife Service and the California Department of
Fish and Game. EPA would appreciate your response prior to October 1,1992. Please
direct any questions or requests for further information to Shelley Clarke at (415) 744-
1162.
Sincerely,
Y. Hashimoto, Chief
Marine Protection Section
Enclosures (2)
5_]7 Printed on Recycled Paper
-------
EXHIBIT 4
sr
\
? UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IX
75 Hawthorne Street
San Francisco, Ca. 94105-3901
Mr. John Turner, Acting Chief
Environmental Services Division
California Department of Fish and Game
1416 Ninth Street
Sacramento, CA 95814
Dear Mr. Turner:
The Environmental Protection Agency Region IX (EPA) is preparing an
Environmental Impact Statement (EIS) for the designation of an ocean
dredged material disposal site off San Francisco, California. The site will be
selected as part of the Long-Term Management Strategy (LTMS) for San
Francisco Bay and will have the capacity to accomodate an estimated 400
million cubic yards of dredged material over a 50-year period. The proposed
action will involve only the designation of the site itself; before disposal is
permitted, dredged material must be evaluated in accordance with the Marine
Protection, Research and Sanctuaries Act of 1972 and its implementing
regulations and guidance.
EPA began the site designation process by evaluating four study areas on
the Farallon Shelf and Slope at distances of 20 to 55 miles offshore and at
depths of 300 to 6000 feet. The four study areas are delineated on the enclosed
map (areas 2-5) and coordinate list. With the recent designation of the
Monterey Bay National Marine Sanctuary Study Areas 2 and the eastern third
of Study Area 3 are no longer being considered as potential sites. However,
since data have been collected for all four study areas, a characterization of
each area is being developed. In the draft EIS, which is scheduled for release
in November 1992, EPA will identify candidate sites within Study Areas 3, 4
and 5 and will choose a preferred alternative site.
EPA is requesting an endangered species consultation pursuant to the
State Endangered Species Act. Therefore, please advise EPA of the presence of
any listed, or candidate, threatened or endangered species, or species of special
concern, in the vicinity of the four study areas identified above. In addition,
please advise EPA of any critical habitat for these species which may be
impacted by the proposed action. EPA will use this information in the
preparation of the Draft Environmental Impact Statement and will forward
this information to the California Coastal Commission as part of the site
Printed on Recycled Paper
5-18
-------
EXHIBIT 4 (continued)
designation coastal consistency package we will prepare. Similar Federal
consultations have been initiated with the U.S. Fish and Wildlife Service and
the National Marine Fisheries Service. EPA would appreciate your response
prior to October 1,1992. Please direct any questions or requests for further
information to Shelley Clarke at (415) 744-1162.
Sincerely,
Y. Hksfiimoto, Chief
Marine Protection Section
Enclosures (2)
5-19
-------
EXHIBITS
f«l>
\
I ^\/2. j? UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
\ ,s
-------
Table 5.5-1. Distribution List for Draft Environmental Impact Statement (DEIS).
Members listed alphabetically by affiliation.
Name
Organization
Federal Agencies
Nancy Homor
Edward Ueber
Herb Curl
Martin Eckes
James Bybee
Dr. Alec MacCall
Don Pearson
Michael Thaubault
LL Col. Len Cardoza
Roderick Chisholm
Calvin Fong
Richard Stradford
Thomas Wakeman
William McCoy
Commander Scot Tiernan
Patricia Sanderson Port
Marvin Plenert
Wayne White
Michael Field
Herman Karl
Marlene Noble
John Kennedy
Curt Collins
Steven Ramp
Sherman Seelinger
Federal Maritime Commission
Fort Point National Historic Site
Golden Gate National Recreation Area
Gulf of the Farallones National Marine Sanctuary
National Oceanic and Aeronautical Administration Hazardous Materials,
NOAA/N/OMA34
National Oceanic and Aeronautical Administration Headquarters, N/SPA
National Marine Fisheries Service
National Marine Fisheries Service
National Marine Fisheries Service
National Marine Fisheries Service
San Francisco District, U.S. Corps of Engineers
San Francisco District, U.S. Corps of Engineers
San Francisco District, U.S. Corps of Engineers
San Francisco District, U.S. Corps of Engineers
San Francisco District, U.S. Corps of Engineers
South Pacific Division, U.S. Corps of Engineers
South Pacific Division, U.S. Corps of Engineers
South Pacific Division, U.S. Corps of Engineers
U.S. Coast Guard Marine Safety Office
U.S. Coast Guard Marine Safety Office
U.S. Department of the Interior
U.S. Department of the Interior
U.S. Fish and Wildlife Service
U.S. Fish and Wildlife Service
U.S. Geological Survey
U.S. Geological Survey
U.S. Geological Survey
U.S. Naval Facilities Engineering Command
U.S. Naval Postgraduate School
U.S. Naval Postgraduate School
U.S. Navy Western Division
AK0171.W51
5-21
-------
Table 5.5-1. Continued.
Name
Organization
Interest Groups
Don Anderson
Bill Boland
Lou Drake
Tom Jow
Margaret Johnson
Michael Herz
Ellen Johnck
George Plant
Philip Plant
Lloyd Dodge
Mike Cheney
Ray Krone
Robert Langner
Laurel Marcus
Mike Corker
Jill Kauffman
Alan Ramo
Kathleen van Velsor
William Dorresteyn
Levia Stein
James Robertson
John Karas
independent
independent
independent
independent
Aquatic Habitat Institute
Audubon Society, Golden Gate Chapter
Bay Institute of San Francisco
Bay Keeper
Bay Planning Coalition
Benicia Port Terminal
Benicia Industries, Inc.
Bodega Marine Laboratory
California Association of Harbormasters and Port Captains
California Maritime Affiliation and Naval Conference (CMANC)
California Maritime Affiliation and Naval Conference (CMANC)
California Maritime Affiliation and Naval Conference (CMANC)
California Academy of Sciences
California Coastal Conservancy
California Marine Mammal Center
California Waterfowl Association
Center for Marine Conservation
Chevron U.S.A., Inc.
Citizens for a Better Environment
Coastal Advocates
Dredge Rep Operating Engineers Local #3
Dutra Construction Company
EXXON Refining Company
Earth Island Institute
Environmental Defense Fund
Environmental Forum of Marin
Golden Gate Fisherman's Association
Great Lakes Dredging Company
AK0171.W51
5-22
-------
Table 5.5-1. Continued.
Name
Karen Topakian
Pietro Parravano
Cynthia Koehler
Dr. Victor Jones
Barbara Salzman
Karen Urquhart
J. Martin •
Daniel Bacher
Margaret Elliot
Leonard Long
Zeke Grader
Miles Butler
David Ainley
Sarah Allen
John Lunz
Captain AJ. Thomas
Dr. Doug Segar
James Haussener
Barry Nelson
Daniel Glaze
Organization
Greenpeace Action
Half Moon Bay Fisherman's Association
Headlands Foundation
Heller, Ehrman, White and McAuliffe
Intra-Govemmental Studies, University of California at Berkeley
Latitude 38 Magazine
League for Coastal Protection
League of Women Voters, Bay Area
Manson Construction and Engineering Company
Marin Audubon Society/Conservation League
Marine Conservation League
Marine Science Institute
Moss Landing Commercial Fisherman's Association
Moss Landing Marine Laboratory
National Audubon Society, Marin Chapter
National Audubon Society, Sequoia Chapter
Nature Conservancy, California Field Office
Northern California Angling Publication
Oakland Chamber of Commerce
Ocean Alliance
Ocean Research Institute
PICYA/RBOC
Pacific Coast Federation of Fishermen's Association
Pacific Refinery Company
Point Reyes Bird Observatory
Point Reyes Bird Observatory
Science Applications International Corporation
San Francisco Bar Pilots
San Francisco Bay Bird Observatory
San Francisco State University
San Leandro Marina
Save San Francisco Bay Association
Shell Oil Co.
AK0171.W51
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Table 5.5-1. Continued.
Name
David Nesmith
Wendy Eliot
Kim Brown
Roger Lockwara
Leo Cronin
Ken Guziak
John Beuttler
Richard Peterson
Richard Bailey
Organization
Sierra Club
Sierra Club, San Francisco Bay Chapter
State Coastal Conservancy
Stuyvesant Dredging Company
Tetra Tech
Tiburon Center for Environmental Studies, San Francisco State
University
Tosco Refining Co.
Trout Unlimited
UNOCAL, San Francisco Refinery
United Anglers of America
United Surf Riders
Water Quality Association
Western Pacific Dredging Company
Local Agencies
Sally Germain
Steven Szalay
James McGrath
Charles Roberts
Floyd Shelton
M. Powers
Eugene Serex
Michael Huerta
Veronica Sanchez
ABAG Clearinghouse
Alameda County
Association of Bay Area Governments
Board of Port Commissioners, Oakland
City and County of San Francisco
City of Redwood City
City of Richmond
Contra Costa County
Marin County
Napa County
Port of Oakland
Port of Oakland
Port of Redwood City
Port of Richmond
Port of Richmond
Port of San Francisco
Port of San Francisco
Port of Stockton N
AK0171.W51
5-24
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Table 5.5-1. Continued.
Name
Gail Louis
James Harberson
Organization
San Francisco Estuary Project
San Mateo County
Santa Clara County
Sonoma County
Libraries
ABAG/MTC Library
Alameda County Library
Bancroft Library, University of California
Berkeley Public Library
Daly City Public Library
Environmental Information Center, San Jose State University
Half Moon Bay Library
Marin County Library, Civic Center
North Bay Cooperative Library System
Oakland Public Library
Richmond Public Library
San Francisco Public Library
San Francisco State University Library
San Mateo County Library
Santa Clara County Free Library
Sausalito Public Library
Stanford University Library
U.S. Representatives
Honorable Ronald Dellums
Honorable Vic Fazio
Honorable Wally Herger
Honorable Tom Lantos
Honorable George Miller
Honorable Nancy Pelosi
Honorable Fortney Stark
U.S. House of Representatives
U.S. House of Representatives
U.S. House of Representatives
U.S. House of Representatives
U.S. House of Representatives
U.S. House of Representatives
U.S. House of Representatives
AK0171.W51
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Table 5.5-1. Continued.
Name
Organization
U.S. Senators
Honorable Barbara Boxer
Honorable Dianne Feinstein
U.S. Senate
U.S. Senate
State Agencies
Bob Potter
George Larsen
Wes Ervinh
Mark Delaplaine
Peter Douglas
George Armstrong
Robert Tasto
John Turner
Michael Kahoe
Douglas Wheeler
John Geoghegan
Michael Carlin
Paul Jones
Marion Otsea
Steven Ritchie
Jeptha Wade
Steve Goldbeck
Alan Pendleton
Linda Martinez
Charles Warren
Fred La Caro
Bay Area Air Quality Management District
California Department of Water Resources
CALTRANS
California Integrated Waste Management Board
California Commerce Department
California Coastal Commission
California Coastal Commission
California Coastal Commission
California Department of Boating and Waterways
California Department of Boating and Waterways
California Department of Fish and Game
California Department of Fish and Game
California Department of Health Servics
California Environmental Protection Agency
California Resource Agency
California State Air Resources Board
Department of Business, Transportation, and Housing
San Francisco Bay Regional Water Quality Control Board
San Francisco Bay Regional Water Quality Control Board
San Francisco Bay Regional Water Quality Control Board
San Francisco Bay Regional Water Quality Control Board
San Francisco Bay Regional Water Quality Control Board
San Francisco BCDC
San Francisco BCDC
State Lands Commission
State Lands Commission
State Water Resources Control Board
AK0171.W51
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Table 5.5-1. Continued.
Name
Organization
California Representatives
Honorable Tom Bates
Honorable Willie Brown, Jr.
Honorable John Burton
Honorable Robert Campbell
Honorable Barbara Lee
Honorable Ted Lempert
Honorable Jackie Speier
James Alford
California State Assembly
California State Assembly
California State Assembly
California State Assembly
California State Assembly
California State Assembly
California State Assembly
State of California Assembly, Speaker's Office
California Senate
Honorable Barry Keene
Honorable Quentin Kopp
Honorable Milton Marks
Honorable Rebecca Morgan
Honorable Nicholas Petris
California State Senate
California State Senate
California State Senate
California State Senate
California State Senate
AK0171.W51
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can be viewed at any of the libraries listed in Table 5.5-2. Comments received from reviewers
and responses to these comments will be included in the Final Environmental Impact Statement.
AK0147.WS1
5-28
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Table 5.5-2. Locations Where the DEIS Can Be Reviewed or Requested.
Copies of this DEIS may be reviewed at the following locations:
ABAG/MTC Library
101 - 8th Street
Oakland, CA 94607
Oakland Public Library
125 - 14th Street
Oakland, CA 94612
Alaraeda County Library
3121 Diablo Avenue
Hayward, CA 94545
Richmond Public Library
325 Civic Center Plaza
Richmond, CA 94804
Bancroft Library
University of California
Berkeley, CA 94720
San Francisco Public Library
Civic Center, Larkin and McAllister
San Francisco, CA 94102
Berkeley Public Library
2090 Kittredge Street
Berkeley, CA 94704
San Francisco State University Library
1630 Holloway Avenue
San Francisco, CA 94132
Daly City Public Library
40 Wembley Drive
Daly City, CA 94015
San Mateo County Library
25 Tower Road
San Mateo, CA 94402
Environmental Information Center,
San Jose State University
125 South 7th Street
San Jose, CA 95112
Santa Clara County Free Library
1095 N. 7th Street
San Jose, CA 95112
Half Moon Bay Library
620 Correas
Half Moon Bay, CA 94019
Sausalito Public Library
420 Litho Street
Sausalito, CA 94965
North Bay Cooperative Library System
725 Third Street
Santa Rosa, CA 95404
Stanford University Library
Stanford, CA 94035
Marin County Library, Civic Center
3501 Civic Center Drive
San Rafael, CA 94903
Copies of this DEIS may be requested by writing to the following address:
U.S. Environmental Protection Agency
Region IX
Marine Protection Section, W-7-1
ATTN: Shelley Clarke
75 Hawthorne Street
San Francisco, CA 94105
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AK0147.WS1 5-30
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CHAPTERS
PREPARERS AND CONTRIBUTORS
This chapter provides a list of EIS preparers (Table 6-1) and contributors (Table 6-2).
6-1
-------
Table 6-1. List of EIS Preparers.
NAME
EXPERTISE
EXPERIENCE
RESPONSIBILITY
U.S. Environmental Protection Agency
Shelley Clarke, M.S.
Allan Ota, M.S.
Fisheries
Marine Policy
Biological Oceanography
Seven years conducting research and
preparation and review of technical
reports.
Twelve years conducting research and
preparation and review of technical
reports.
Technical Program Manager and EIS
review.
Field Studies Manager and EIS review.
Contractor;
Science Applications International Corporation
James Blake, Ph.D.
John Clayton, Ph.D.
Debra Davison, M.S.
Joseph Germane, Ph.D.
Peter Hamilton, Ph.D.
Benthic Biology/Ecology
Biological Oceanography
Environmental Chemistry
Marine Biology
Marine Sciences
Dredged Material Impacts
Physical Oceanography
Over 20 years conducting ecological
research in benthic environments.
Over 20 years research in
environmental chemistry and marine
sciences.
Seven years conducting research and
preparation of technical reports.
Over 15 years conducting environmental
studies focusing on dredged material
impacts.
20 years conducting research in
physical oceanography.
Preparation and review of EIS section:
Affected Environment
Preparation of EIS section:
Affected Environment
Preparation of EIS sections:
Affected Environment
Environmental Consequences
Coordination
EIS review
EIS review
Preparation of EIS section:
Environmental Consequences
Os
to
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NAME
EXPERTISE
EXPERIENCE
RESPONSIBILITY
Mike Hart (M.S., in Progress)
Environmental Chemistry
Over four years conducting research
and preparation of technical reports.
Preparation of EIS section:
Affected Environment
Daniel J. Heilprin, M.S.
Marine Sciences
Ichthyology
Fisheries Biology
Over five years conducting ecological
studies and preparation of technical
reports.
Preparation of EIS sections:
Affected Environment
Environmental Consequences
List of Preparers and Contributors
EIS review
Robert Kelly, Ph.D.
Marine Sciences
Dredged Material Impacts
EIS Preparation
Over 15 years conducting environmental
studies, including EIS preparation and
impact assessment.
Preparation of EIS sections:
Introduction
Affected Environment
Environmental Consequences
Andrew Lissner, Ph.D.
Marine Biology
Dredged Material Impacts
EIS Preparation
Over 15 years conducting environmental
studies, including EIS preparation and
impact assessment.
Work Assignment Manager
Preparation of EIS sections:
Affected Environment
Environmental Consequences
EIS review
John Lunz, M.S.
Marine Sciences
Dredged Material Impacts
Over 15 years conducting dredged
material research studies and impact
assessment.
Preparation of EIS section:
Affected Environment
EIS review
Joann Muramoto, Ph.D.
Marine Geochemistry
Over 10 years conducting geochemical
research.
Preparation of EIS section:
Affected Environment
Charles Phillips, M.A.
Biology
Chemistry
EIS Preparation
15 years conducting environmental
studies, including EIS preparation and
impact assessment.
EIS Task Manager
Preparation of EIS sections:
Introduction
Alternatives
Affected Environment
Environmental Consequences
EIS review
AK0140.W5I
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NAME
William J. Reynolds, Ph.D.
Donald Rhoads, Ph.D.
Bo Shmorhay
Sridhar Srinivasan, MA.
Isabella Williams, M.S.
EXPERTISE
Coastal Geomorphology
Benthic Processes
Technical Editing
Economics
Political Science
Marine Biology
EXPERIENCE
Almost 30 years conducting research in
coastal geomorphology, project
management, and teaching.
More than 30 years conducting benthic
studies and assessing marine
environmental impacts.
Over 10 years performing editing and
production of technical reports and
studies.
Two years environmental and
institutional analyses.
More than 20 years in marine sciences.
RESPONSIBILITY
Preparation of EIS section:
Affected Environment
EIS review
Preparation of EIS sections:
Affected Environment
Environmental Consequences
EIS review
Editing and Production of EIS
Preparation of EIS sections:
Affected Environment
Environmental Consequences
Preparation of EIS section:
Affected Environment
AK0140.W51
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Table 6-2. List of EIS Contributors.
NAME
AFFILIATION
David Ainley
Sarah Allen
James Barry
James Bence
Sue Benech
Gregor Cailliet
John Chin
Curtis Collins
David Drake
Brian Edwards
Paul Jessen
Newell Garfield
Paul Jones
Herman Karl
William Lenarz
Guillermo Moreno
Marlene Noble
James Nybakken
Steve Osbom
Steven Ramp
Dale Roberts
Leslie Rosenfeld
William Schwab
Franklin Schwing
Isidore Szcezepaniak
Point Reyes Bird Observatory
Point Reyes Bird Observatory
Monterey Bay Aquarium Research Institute
National Marine Fisheries Service, Tiburon Laboratory
Benech Biological and Associates
Moss Landing Marine Laboratories
U.S. Geological Survey
Naval Postgraduate School
U.S. Geological Survey
U.S. Geological Survey
Naval Postgraduate School
Naval Postgraduate School
U.S. Environmental Protection Agency, Region IX, San Francisco
U.S. Geological Survey
National Marine Fisheries Service, Tiburon Laboratory
Moss Landing Marine Laboratories
U.S. Geological Survey
Moss Landing Marine Laboratories
Moss Landing Marine Laboratories
Naval Postgraduate School
National Marine Fisheries Service, Tiburon Laboratory
Naval Postgraduate School
U.S. Geological Survey
Naval Postgraduate School
California Academy of Sciences
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6-6
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CHAPTER?
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