WATER POLLUTION CONTROL RESEARCH SERIES
18080 GBX 12/71
BIOLOGICAL IMPACT OF A
LARGE-SCALE DESALINATION
PLANT AT KEY WEST
U.S. ENVIRONMENTAL PROTECTION AGENCY
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WATER POLLUTION CONTROL RESEARCH SERIES
The Water Pollution Control Research Series describes the
results and progress in the control and abatement of pollution
in our Nation's waters. They provide a central source of
information on the research, development, and demonstration
activities in the water research program of the Environmental
Protection Agency, through inhouse research and grants and
contracts with Federal, State, and local agencies, research
institutions, and industrial organizations.
Inquiries pertaining to Water Pollution Control Research
Reports should be directed to the Chief, Publications Branch
(Water), Research Information Division, R&M, Environmental
Protection Agency, Washington, DC 20460.
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BIOLOGICAL IMPACT OF A LARGE-SCALE
DESALINATION PLANT AT KEY WEST
by
Richard H. Chesher
Westinghouse Ocean Research Laboratory
Annapolis, Maryland
for the
OFFICE OF RESEARCH AND MONITORING
ENVIRONMENTAL PROTECTION AGENCY
Project No. 18080 GBX
Contract # 14.12.888
December, 1971
For sale by the Superintendent of Documents, U.S. Government Printing Office, Washington, D.C. 20402 - Price $1.25
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EPA REVIEW NOTICE
This report has been reviewed by the Environmental
Protection Agency, EPA, and approved for publication.
Approval does not signify that the contents necessar-
ily reflect the views and policies of the Environ-
mental Protection Agency, nor does mention of trade
names or commercial products constitute endorsement or
recommendation for use.
ii
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ABSTRACT
An eighteen month, biological study showed the heated brine effluent
from a desalination plant in Key West, Florida caused a marked re-
duction in biotic diversity. Some organisms were more abundant in
the receiving waters than in control areas but these were generally
capable of isolating themselves from the effluent by closing up
or by moving to other areas during periods of high contamination.
Ionic copper, discharged from the plant, was the most toxic feature
of the effluent. Temperature and salinity of the effluent and the
receiving water were such that the effluent stratified at the bottom
of the receiving basin. This stratification reduced water circula-
tion and the man-made harbor acted as a settling basin which lessened
the impact of the discharge on surrounding natural environments.
Periodically, the plant shut down for maintenance or cleaning. When
it resumed operations, low temperature water of ambient salinity was
discharged which was highly contaminated with ionic copper. These
sudden effusions caused more biological damage than steady-state con-
ditions. At the end of the study, extensive engineering changes were
made to correct corrosion problems and lower copper discharge.
This report was submitted in fulfillment of Contract No. 14.12.888
under the sponsorship of the Environmental Protection Agency.
iii
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CONTENTS
Section Page
I CONCLUSIONS 1
The Effluent and its Distribution 1
Effusions and their Distribution 2
General Biological Impact of the Effluent
and Effusions 2
Assessment of Experimental Design 4
Effluent Dispersion 5
Biological Investigation 6
Summary of Conclusions 7
II RECOMMENDATIONS 11
III INTRODUCTION 13
IV MATERIALS AND PROCEDURES 17
Desalination Plant Operation 17
Characterization of the Effluent 17
Station Locations 20
Effluent Dispersion 20
Biological Investigations 30
Quadrat and Biomass Samples 30
Transects 32
Plankton Tows 33
Settlement Panels and Diatometers 33
Transplants 34
Laboratory Bioassays 36
Graphic Techniques 38
v
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Section Page
V SAFE HARBOR 41
Bathymetry 41
Water Circulation 41
Tidal Flushing 43
Sediments 43
VI PHYSICAL PARAMETERS 45
Desalination Plant Operation 45
Ambient Conditions 45
Effluent Distribution 45
Distribution at Point of Discharge 43
Distribution of Effluent Stratum 43
Copper and Nickel 58
VII HISTORICAL ANALYSIS OF SAFE HARBOR SEDIMENTS 55
Heavy Metals in the Sediments 65
Foraminifera 70
VIII BIOLOGICAL PARAMETERS 77
Concentrations of Effluent at Biological
Stations 77
Quadrat Analysis 77
Foraminifera 92
Transects 92
Plankton Tows 100
Settlement Panels 102
Diatometers
In situ Bioassays
Laboratory Bioassays
Copper Toxicity
VI
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Section Page
IX ACKNOWLEDGEMENTS 143
X REFERENCES 145
XI APPENDIX A 149
VI1
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FIGURES
Page
1 Projection of future world-wide desalting use. 14
2 Schematic diagram of the operation of the Key
West desalination plant. 18
3 Phase II station locations in Safe Harbor,
Stock IsIant, Florida Keys. 21
4 Schematic of biological station installation
near the top of a vertical canal wall. 23
5 Location of thermister strands in Safe Harbor
Canal. 27
6 Dates of dredging and filling in Safe Harbor. 29
7 Bioassay experiments. 37
8 Monthly mean percent effluent and the 90 percent
confidence limits of the mean at Station 3C, 73m
(240 feet) from the discharge of the desalination
plant. 39
9 Bathymetry of Safe Harbor. 42
10 Monthly operating parameters of the Key West
desalination plant from August, 1970 to
August, 1971. 46
11 Average monthly physical parameters from all
stations in Safe Harbor from August, 1970 to
August, 1971. 47
12 Twelve month average of the rise in temperature
and salinity caused by the desalination plant
effluent at all stations in Safe Harbor. 49
13 Average monthly depth of the effluent stratum
at all stations in Safe Harbor. 51
14 Average monthly rise in temperature caused by
the desalination plant effluent at all stations
in Safe Harbor. 53
15 Isotherms in Safe Harbor Channel March 12, 1970
from 1200 to 1205 hours. 54
viii
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16 Isotherms in Safe Harbor Channel May 14, 1971
from 1005 to 1010 hours. 55
17 Movement of 25 °C isotherm in Safe Harbor Channel
March 12, 1970 from 1220 to 1730 hours. 56
18 Movement of 29°C isotherm in Safe Harbor Channel
May 14, 1971 from 0900 to 1900 hours. 57
19 Monthly average copper concentrations at all
stations. 63
20 Distribution of copper (ppm dry sediment) in
upper centimeter of sediment in Safe Harbor. 66
21 Age of sediment layers in core samples 67
22 Copper and nickel concentrations in the sediment
at Bay 2 from 1952 to present. 68
23 Copper and nickel concentrations in the sediment
at Station 3 from 1950 to present. 69
24 Species diversity in foraminifera population
from core sample at Station 3 and at Bay 2. 73
25 Numbers of foraminifera per cc of dry sediment
from core samples at Station 3 and at Bay 2. 74
26 Monthly percent effluent at each station in
Safe Harbor from August, 1970 to August, 1971. 78
27 Mean percent effluent with 90 percent confidence
limits of the mean for all deeper stations in
Safe Harbor from August, 1970 to October, 1971. 79
28 Dominance diversity indices for all Safe Harbor
stations based on collections accumulated from
July, 1970 to October, 1971. 85
29 Two largest similarity indices for each station
in Safe Harbor, indicating affinities in population
structures from July, 1970 to October, 1971. 87
30 Similarities in population structure between
shallow stations in Safe Harbor from July, 1970
to October, 1971. 88
31 Similarities in population structure between deep
stations in Safe Harbor from July, 1970 to October,
1971. 89
IX
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32 Live foraminifera per cc of wet sediment found
at all shallow water stations from October, 1970
to October, 1971. 93
33 Live foraminifera per cc of wet sediment found
at all deep water stations from October, 1970 to
October, 1971. 94
34 Number of individuals per 100 feet of canal wall
in Safe Harbor, Stock Island, Florida Keys July,
1970 to October, 1971. 96
35 Numbers of Lyteohinus vazn-egatus and Tripneustes
ventricosus per square meter in Thalassia flats
east and west of the Safe Harbor turning basin. 99
Aerial surveys of turtle grass beds adjoining
the Safe Harbor turning basin (1968-1971).
36
101
37 Numbers of serpulids on thirty-day settlement
panels at shallow water Safe Harbor stations
November, 1970 to April, 1971. 103
38 Numbers of serpulids on thirty-day settlement
panels at shallow water Safe Harbor stations
May, 1971 to October, 1971. 104
39 Numbers of serpulids on thirty-day settlement
panels at deep water Safe Harbor stations October,
1970 to April, 1971. 105
40 Numbers of serpulids on thirty-day settlement
panels at deep water Safe Harbor stations May,
1971 to October, 1971. 106
41 Mean number of serpulids settling per 50 cm2 per
month at biological stations in Safe Harbor. 107
42 Monthly indices of serpulids settling on 50 cm2
wooden panels at biological stations in Safe
Harbor compared to effluent exposure November, 1970
to April, 1971. 109
43 Monthly indices of serpulids settling on 50 cm2
wodden panels at biological stations in Safe
Harbor compared to effluent exposure May, 1971
to October, 1971.
44 Mean number of barnacles settling per 50 cm2 per
month at biological stations in Safe Harbor.
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45 Mean number of sabellids settling per 50 cm2 per
month at biological stations in Safe Harbor. 113
46 Monthly average of diatom and protozoan species
per 2 mm2 at Safe Harbor and control stations. 114
47 Monthly averages of diatoms and protozoans per
mm2 at Safe Harbor and control stations. 115
48 Monthly averages of Vortioella settling at Safe
Harbor and control stations. 117
49 Monthly averages of Nit-zsahia longissima settling
at Safe Harbor and control stations. 118
50 Echinoid survival versus maximum percent effluent
during exposure. 121
51 Average number of days survived by gorgonians
(Pterogorgia anceps) at "A" series stations from
August, 1970 to March, 1971 and average percent
effluent at "B" series stations during this period. 125
52 48 and 96-hour TLm acute bioassay of desalination
plant effluent on Lytechinus variegatus. 127
53 48 and 96-hour TLm acute bioassay of desalination
plant effluent on Asoidia nigra. 128
54 48 and 96-hour TLm acute bioassay of desalination
plant effluent on Menippe mercenaria. 129
55 24-hour, 50 percent reduction of photosynthetic
rate of Thalassia testudimm exposed to various
dilutions of desalination plant effluent. 130
56 Comparison of toxic effects of copper in effluent
and in seawater on Lyteohinus variegatus. 132
57 Comparison of toxic effects of copper in effluent
and in seawater on Asoidia nigra. 133
58 Comparison of toxic effects of copper in effluent
and in seawater on Menippe mercenaria. 134
59 Comparison of toxic effects of copper in effluent
and in seawater on photosynthetic rates of
'Fhalassia testudinian. 135
60 Maximum monthly barnacle growth compared to total
average dissolved copper exposure April, 1971 to
October, 1971. 140
xi
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TABLES
Page
I Biological station summary. 22
II Analysis of effluent from Key West desalination
plant. 59
III Ionic analysis of effluent. 61
IV Temporal distribution of foraminifera in
sediment cores from Station 3 and Bay 2
Safe Harbor. 71
V List of invertebrates and algae found at all
stations between July, 1970 and October, 1971. 81
VI Faunal similarity indices between Safe Harbor
stations. 86
VII Transect comparisons 1969, 1970, 1971. 97
VIII Mean abundance of a ciliate protozoan (Vortioetla)
and a diatom (Nitzsahia) settling per mm2 on
diatometers at Safe Harbor and control stations.
IX Survival of echinoids at biological stations
September, 1970 to June, 1971. 120
X Number of echinoid deaths related to start-ups,
shut-downs, unstable plant operation or normal
operation of the desalination plant from
October, 1970 to October, 1971. ^23
Xll
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SECTION I
CONCLUSIONS
THE EFFLUENT AND ITS DISTRIBUTION
The desalination plant produced two types of discharge; one emitted
when the plant was operating normally (effluent), the other produced
during cleaning and maintenance cycles (effusions).
The effluent was turbulently mixed with the ambient water at the point
of discharge and, because the combined density was greater than ambient
water, it sank to the bottom of the man-made Safe Harbor. Since the
harbor was deeper than surrounding flats, the submerged effluent filled
the basin to the depth of the surrounding flats. Surplus effluent then
flowed onto the flats and mixed with the shallower water.
The biota occupying portions of the harbor below 16 feet (4.9m) was
constantly exposed to the major contaminants: heat, salinity, and
copper. Temperature and salinity controlled the depth and density of
the effluent stratum but they were not biologically damaging by them-
selves. The effluent stratum averaged only 0.3 to 0.5°C above ambient
temperatures and only 0.2 to 0.5 o/oo above ambient salinities. To-
gether they caused the effluent to stratify and reduced the mixing
rate of the other major contaminant - copper. Consequently, copper
concentrations were often five to ten times above ambient levels;
amounts found toxic to experimental animals in acute toxicity bio-
assays.
Although this situation proved deleterious for the biota in deeper
portions of Safe Harbor, the configuration of the system protected
shallower areas in the harbor and the surrounding Jhalassia flats.
Poor water circulation in the deeper Safe Harbor water created an
enormous settling tank. Effluent remained in the effluent stratum
from 24 to 48 hours and copper, the major deleterious feature of the
effluent, was actively absorbed onto sediments during this time. Some
copper also precipitated out of the water when the effluent became
super-saturated with copper.
Thus, distribution of the effluent was fortuitous during normal plant
operation. It was unfortunate that copper was produced in toxic quan-
tities but the biological impact would have been more widely distri-
buted had the effluent been discharged into a shallower embayment or
directly onto the flats.
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EFFUSIONS AND THEIR DISTRIBUTION
Periodically, the desalination plant produced a second type of
discharge; low in temperature and salinity but high in copper,
nickel, and iron. During most of the study copper discharge was
high; amounting to between 50 to 100 pounds (22.7 to 45.4 kg) lost
per day. When the plant shut down for maintenance the corroded
copper-nickel surfaces dried and oxidized. When resumption of
activities began,the loosened copper powder and scale was washed into
the sump with the first water circulated through the system.
For the first few hours of operation, when the plant was building up
vacuum and heating brine, there was little concentration of the well
water and the discharge was, consequently, close to normal seawater
in salinity and temperature. Copper contamination, however, was two
to three times higher than 'normal' and the discharge was turbid and
black. Because the salinity and temperature were close to ambient
levels, the turbid, copper-laden effusions mixed well with ambient
water and did not sink. Consequently, the shallower areas of the
harbor and surrounding flats were inundated by copper effusions each
time the plant started up.
The dispersion of effusions varied with wind currents and tidal movements.
They maintained their turbid characteristics for some distance from the
plant and could be visually identified by the black water extended
from the inner harbor to the Thalassia flats west of the turning basin.
GENERAL BIOLOGICAL IMPACT OF THE EFFLUENT AND EFFUSIONS
The fauna and flora of Safe Harbor were adversely affected by the
effluent from the desalination plant. Some species of animals were
prolific in the harbor, however, including foraminifera, serpulid and
sabellid annelid worms, and barnacles. Other organisms, such as fish,
were abundant in the canal but were continuously recruited from
adjacent areas and could also avoid the periodic, turbid effusions.
All of the biological experiments showed the effluent had a pronounced
impact on the biological system within Safe Harbor. Even the organisms
which were more abundant at Safe Harbor stations than at control
stations were adversely affected in the immediate vicinity of the discharge.
A variety of organisms vanished from the harbor during the course of
the fifteen months of field work. Sea squirts (Asoidia nigra), various
species of algae, bryozoans, and sabellid worms were excluded during at
least a portion of the study. Dead shells of various clams and oysters
were abundant in the harbor, many of them still attached to the coral
rock canal walls. Live specimens were relatively common when the pre-
liminary survey was conducted in 1968 and 1969 (Clarke et al 1970) but
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by 1970 they were rare. By 1971, no live lamellibranchs were found
in the harbor.
Effects of the effluent were less at the stations in the turning basin
and not detectable at the stations in the approach canal seaward of the
turning basin. On the grass flats to the west of the Safe Harbor
turning basin, echinoids were killed by the effluent but the rest of
the fauna and flora remained relatively stable from 1968 to 1971.
Effusions following the start-up of the desalination plant after
maintenance operations caused more biological damage than effluent
from the normally operating desalination plant, especially at shallow
water stations normally not subjected to effluent. Maintenance work
increased as the study progressed with the result that effusions were
more common in the fall of 1970 and the winter and spring of 1971
than earlier in the study.
When the harbor fauna was assessed in June, 1970 there was a signifi-
cant difference in the deep versus the shallow fauna at all stations.
As the study progressed, and effusions became more common, the differ-
ences between the shallow and deep stations became less pronounced.
By the spring of 1971, effusions had depleted the shallow water Safe
Harbor fauna and the shallow stations were not greatly different from
the deep stations. In the turning basin, however, and at the station
in the innermost portion of the harbor, the shallow stations remained
different from the deep stations throughout the study, indicating the
impact of the deeper effluent stratum was more extensive, geographically,
than the impact of the periodic effusions.
Effusions, however, caused more deaths of experimental animals than the
effluent, even at stations in the turning basin. Between October, 1970
and October, 1971 no experimental animals died at the biological stations
when the plant was operating normally. Prior to October, 1970 numerous
experimental animals died during normal operating conditions and it was
evident that 'normal' effluent was deleterious. Later in the study,
however, effusions became so frequent that the test organisms were
eliminated by transient peaks of contaminants before the long-term
effects could cause mortalities. The success of at least two and possibly
three of the more abundant organisms in Safe Harbor can be attributed to
their ability to avoid the transient peaks of contaminants associated
with effusions from the desalination plant and their ability to tolerate
the steady-state conditions. Fish were able to swim out of the turbid
effusions and were observed doing so. Smaller species of fishes which
fled into holes and crevices in the canal wall did not escape and some
of these were found to have hepatic lesions similar to those found in
fish experimentally poisoned with copper.
Barnacles, by sealing their shells with an operculum, also avoided the
toxic effusions and were able to inhabit rocks immediately in the path
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of the discharge pipe. Serpulids (by far the most common macroin-
vertebrate in Safe Harbor) also inhabited rocks in the immediate
vicinity of the discharge and they also had opercula to seal the
ends of their calcium carbonate tubes.
Comparison of average copper concentrations (without the effusion
copper) and barnacle growth rates proved the barnacles were^not
exposed to the transient high levels of copper associated with effu-
sions. Divers also confirmed that opercula of barnacles exposed to
effusions were closed and that barnacles did not feed during exposure.
Serpulids were also withdrawn and not feeding during exposure to the
effusions.
Sabellids are also tube-worms but these do not have opercula to seal
the entrance to their parchment-like tubes. Although they were common
in Safe Harbor in the summer of 1970 and again in the summer of 1971
(after copper discharges had been reduced) , they had a mass mortality
in October, 1970 and were relatively rare at the biological stations
in the harbor throughout the fall, winter, and spring of 1970-71.
Laboratory bioassays confirmed the hypothesis that copper was the most
toxic element of the effluent. Except for ascidians, copper explained
the observed mortalities in acute bioassay studies. Although the
ascidians were also susceptible to copper toxicity, the effluent was
more toxic than could be explained by the copper contained in it. It
was suggested, but not proven or explained, that synergism of copper
and temperature may be more pronounced for ascidians than for the other
organisms investigated.
ASSESSMENT OF EXPERIMENTAL DESIGN
In setting up the experimental design for this investigation, the re-
searchers included experiments which would adequately delimit the
biological impact of the effluent. Most of the techniques had shown
success in other ecologically-oriented pollution research but some of
the techniques had not been tried before. The final experimental
design, therefore, included experiments which final analysis showed to
be redundant or unproductive or more laborious than the information
gained was worth. It is worthwhile to discuss the relative value of
the various experiments for the benefit of other workers involved in
similar studies.
The experiments are outlined below with the most productive experiments
listed first under the two headings Effluent Dispersion and Biological
Investigations.
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EFFLUENT DISPERSION
1. Copper in the Sediment; Concentration of metals by marine sediments
proved the most useful, least expensive, method of characterizing
the dispersion of the effluent. It was also more sensitive than
hydrographic measurements and had the added benefit of permitting
analysis of the effluent conditions recorded in the sediments dating
back to ambient conditions prior to the construction of the desalina-
tion plant.
2. Dye Observations and in si-tu Diver Observations: Ascertaining the
overall distribution of the effluent and its dynamics was facilitated
by simply following the top of the submerged effluent stratum which
was visually and tactilly detectable by divers. Adding Rhodamine B
dye to the sump and visually following the dye with divers permitted
more accurate analysis of the flow of effluent through the harbor.
3. Temperature Inversion Analysis; The hot effluent stratum was easily
detectable as a temperature inversion. An electric thermometer
proved invaluable in following the dispersion of the effluent and
analyses of the position of the effluent stratum could be made
rapidly from a small boat. Installation of the Westinghouse ther-
mister array permitted instant analysis of the movement of the
effluent in the field and the long-term movements of particular
isotherms.
4. Hydrographic Surveys: The twice-weekly analyses of the water con-
ditions were exceedingly time consuming and probably did not add
significantly to the understanding of the biological impact. An
initial hydrographic survey of one or two months would have pro-
vided an adequate knowledge of the relationship of the effluent
in the water column to the amount of copper in the sediment or to
temperature inversions and these could have supplanted the less
productive and time consuming hydrographic surveys. Of the variety
of parameters measured, temperature, salinity, and copper provided
the most useful data as they controlled movement of the effluent
stratum and its relative toxicity. Alkalinity, pH, and oxygen
measurements were not greatly influenced by the effluent and occa-
sional (perhaps monthly) measurements would have sufficed.
The worst feature of the regular hydrographic surveys was their
failure to record rapid changes induced by sudden effusions from
the desalination plant. These high, transient peaks were more
important in damaging the environment than the normal effluent
and deserved closer attention. Future surveys should plan to
incorporate the analysis of these effusions in hydrographic sur-
veys.
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BIOLOGICAL INVESTIGATIONS
1. Analyses of Foraminifera; The foraminifera, because they are
small, shelled protozoans, had several attributes which made them
one of the most profitable animal groups studied. They left
easily identifiable shells in the sediment when they died. These
shells provided a biological history of the benthos which could
be compared to the copper and nickel history of the sediments
and yielded information on conditions in Safe Harbor dating back
to before the plant was built.
In the collection of any biological field data, it is important
to obtain enough specimens to be statistically valid and to be
confident of obtaining the most representative species at any
particular station. Foraminifera were easy to collect in large
numbers and were readily identified. Foraminifera experts are
not uncommon and foraminifera identification catalogues have
received considerable attention from geologist of oil companies.
2. Settlement Panels: The second most useful biological data came
from the wooden settlement panels. These collected organisms
over known exposure times and on substrates which were uniform
in size and material. Monthly collections showed availability
of larvae (reproduction and recruitment), diversity, relative
abundance, growth, and mortality of a variety of common fouling
organisms. Because of the uniform exposure and substrate,
quantification of the data were simplified.
3. Transects: Transects proved valuable in assessing general trends
in macroinvertebrates. The transects were more useful than the
quadrats as larger sections of the benthos were examined. They
were oriented toward determining changes in particular organisms
rather than attempting to quantify the entire population structure.
4. Laboratory Bioassays; Acute static bioassays determined the
relative toxicity of the effluent and identified the most toxic
element. The bioassays were not designed to be overly sophis-
ticated yet they yielded the desired information without elaborate
procedures.
5. Quadrat Analyses; Although difficult and time consuming, the
quadrats provided useful information on diversity and population
structure. Similar conclusions were abailable from the foramini-
fera and settlement panel experiments but quadrats included data
on a wider variety o"f organisms.
6. Transplants; Transplant experiments were relatively inexpensive
in terms of time and materials needed for assessment of the in
situ effects on the test animals. Critical examination of the
results, however, showed the only fact of major significance
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provided by the experiments was the extraordinary correlation
of mortalities with the cleaning and maintenance cycles.
While this helped document the importance of effusions, the
same conclusions could be drawn from the bioassays, settlement
panels and transect studies.
7. Biomass Studies; These were difficult and yielded little additional
information not gained from other studies. Since the fauna of the
Safe Harbor canal walls was impoverished and many of the species
living there were rock borers or encrusting organisms the biomass
studies required elaborate and not very successful sampling which
compromised the analysis.
8. Diatometers; Glass microscope slides in special racks
(diatometers) collected benthic diatoms and protozoans for
analyses. They were, however, unsuccessful. While collec-
tion and analysis of the data were neither time consuming
nor costly, variables introduced by filter feeding predators
settling on the glass slides reduced the information con-
tent of the slides. Two slides could not be satisfactorily
compared for differences in benthic diatom or protozoan
populations if one was heavily encrusted with filter-feeding
serpulids (which competed for space and ate the settling organisms)
and the other populated only by diatoms and protozoans.
9. Plankton Tows; The rapidity with which plankton populations
change in nearshore areas limited the information possible
from the periodic plankton tows. Daily plankton tows would
have required considerable expense in return for conclusions
on the impact of the effluent available from other experi-
ments. By comparing plankton populations at the various
stations with one another, some information was gained which
indicated effluent was deleterious to the plankton popula-
tions near the discharge.
10. Cllf Measurements of Photosynthesis; Cllf studies yeilded
unusual results. Frequently more carbon was fixed in the
dark bottle than in the light. This, in itself, was signi-
ficant but a review of the literature suggested the pheno-
menon may be a function of the effect of illumination on
copper toxicity. The variables that entered into the ex-
periment required additional research into the techniques
and theory of Clk measurements which were beyond the scope
of the program.
SUMMARY OF CONCLUSIONS
In addition to the general conclusions outlined above, the following
are pertinent facts obtained during the field work between July,
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1970 and October, 1971.
1. Safe Harbor has an average depth of 22.6 feet. Deep water
circulation is restricted by a 17-foot sill in the approach
channel. Tidal flushing results in a 10.76 million cubic
feet per day exchange. The volume of Safe Harbor is 101.8
million cubic feet.
2. The desalination plant effluent averaged 35°C, 7.0 pH,
50.00 o/oo salinity, and 1,766 ppb copper. Its volume
averaged 1.33 x 108 gal/month or about 0.77 million cubic
feet per operational day.
3. The effluent was diluted about twenty times at the point
of discharge and sank to form a warm, dense stratum which
was found throughout the Safe Harbor basin. The top of
the stratum had an average depth of 18 feet. Although it
occasionally floated in mid-water, it was normally in con-
tact with the bottom. The volume of the effluent stratum
was about 20.6 million cubic feet.
4. The effluent heated the receiving water at deeper stations
in Safe Harbor by an average of 0.2 to 0.5°C and raised its
salinity by an average of 0.2 to 0.45 o/oo over ambient con-
ditions.
5. Diluted effluent escaped from the system along the floor of
the approach canal and along the western edge of the turning
basin.
6. Ambient salinity, the volume of effluent, and the 17-foot
sill in the approach channel controlled the depth of the
effluent stratum. Intensity of the stratum was closely
correlated with total hours of sunshine.
7. Copper was discharged from the desalination plant at con-
centrations up to 6,700 ppb. It was found to be 78.4 per-
cent ionic, 3.4 percent particulate, and 18.2 percent or-
ganically complexed.
8. Copper discharge was highest following plant maintenance
periods and during periods of unstable pH. Raising pH in
the plant significantly reduced copper discharge.
9. Copper in sediments of Safe Harbor and Lindbergh Bay (St.
Thomas, U.S. Virgin Islands) showed the average, long-term
distribution of effluent and provided a permanent record
of copper build-up from pre-plant conditions to the present.
Analysis of copper in sediments is a rapid technique for
determining the average distribution and intensity of effluent,
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10. Foraminifera shells left a permanent record of changes in
sediment fauna from pre-plant conditions to the present.
This record indicated that the foraminifera populations
had increased substantially over pre-plant densities. Num-
bers of species did not change significantly.
11. Densities of live foraminifera decreased in the immediate
vicinity of the discharge but, in general, were higher in
Safe Harbor than at control stations. Conditions improved
for foraminifera during the cooler months.
12. Shallow stations near the desalination plant were exposed to
high concentrations of effluent following shut-down periods.
Sudden, large doses of ionic copper, produced as the plant
began operation or changed operational modes were more dele-
terious than steady-state conditions.
13. Copper and temperature were the two major deleterious as-
pects of the effluent. High discharges of copper resulted
in mortality of test organisms at in si-tu bioassay stations.
14. In situ bioassays showed echinoids and ascidians were more
sensitive to the effluent than stone crabs or gorgonians.
A concentration of only 1.5 percent effluent was lethal to
echinoids in long—term studies. Gorgonians survived brief
exposures to five percent effluent and stone crabs survived
exposures to six to seven percent effluent.
15. Asc-idi-a nigra was the most sensitive organism to effluent
in laboratory acute toxicity experiments; fifty percent
dying in 96 hours in 5.8 percent effluent. Echinoids had
a 96-hour TLm of 8.5 percent effluent; stone crabs a 96-hour
TLm of twelve percent effluent. Photosynthesis of Thalassia
testudLnwn was reduced by fifty percent in twenty-four hours
in concentrations of twelve percent effluent.
16. Fewer specimens of diatoms and protozoans settled on dia-
tometers in effluent-laden water but diversity was not signifi-
cantly decreased. Vovt'loella sp. and Nitsschia longissima
had higher population levels on Safe Harbor shallow water
diatometers and lower populations in deep water diatometers
when compared to control stations.
17. Plankton populations were reduced in deep, effluent-laden
Safe Harbor water when compared to shallow water and con-
trol stations.
18. Serpulids were more abundant in Safe Harbor than at control
stations but their numbers were reduced by effluent-laden
water in the immediate vicinity of the discharge.
-------
19. Effluent reduced numbers of barnacles, bryozoans, and
sabellids settling on settlement panels in Safe Harbor.
20. Asoidia nigra and most oysters were excluded from the
Safe Harbor canal during most of the study period.
A. nigra returned when copper concentrations decreased.
21. Quadrats showed a gradual biotic depletion. Annelid
worms, blue-green algae, and bryozoans comprised the
benthic flora and fauna in Safe Harbor during most of
the study period.
22. Stone crabs and lobsters decreased in transect areas.
Lobsters were attracted to the desalination plant sea
wall during cooler winter months. Fish were more abun-
dant near the discharge than elsewhere in the study
area. Some of these were injured by copper toxicity.
23. Transects showed a decrease in echinoid populations on
Thalassia flats to the west of the Safe Harbor turning
basin. High copper levels in sediments from this area
implicated the effluent in the echinoid mortality.
24. Thalassia grass beds surrounding the entrance to Safe
Harbor did not change their distribution appreciably
between 1968 and 1971.
25. Copper uptake and toxicity increased with increasing
illumination in phytoplankton samples and in the
ascidian, Asoidia nigra.
10
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SECTION II
RECOMMENDATIONS
The primary recommendation would have been to reduce the copper
discharge from the Key West desalination plant but this is in
progress thanks to the environmental concern of the Florida Keys
Aqueduct Commission and the Westinghouse Electric Corporation.
It follows that the second recommendation would be to improve
future desalination plant designs to keep copper discharge at
the lowest possible level. Since copper loss reflects internal
damage to the facility and eventual increased maintenance costs,
it is beneficial to the owners of desalination plants to keep
copper discharge to a minimum. The use of titanium as the pri-
mary heat transfer surface may provide the best solution. Westing-
house Electric Corporation has already constructed a titanium
desalination plant in St. Croix and it would be beneficial to
examine the ecological impact of that plant to ascertain if
titanium is as environmentally compatible as suspected.
It would also be useful to:
1. Examine the modified discharge from the Key West
installation to determine if the engineering changes
do, in fact, reduce the copper discharge.
2. Monitor the biological health of Safe Harbor to
determine how rapidly (and if) it recovers from
the copper polluted environment.
3. Examine the impact of the improved Key West facility
to determine the effects of a desalination plant
with low copper discharge.
4. Design an experimental program to determine the
ecological impact and dispersion of sudden effusions
containing high levels of toxicants.
5. Conduct further investigations into the dynamics and
mechanisms of copper toxicity in the marine environ-
ment.
11
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SECTION III
INTRODUCTION
DESALINATION PLANTS
Large-scale desalination plants are commonplace in many tropical
and subtropical areas where freshwater is limited. A 1970 world-
wide survey by the U.S. Department of the Interior, Office of
Saline Water, showed a total of 686 desalting plants of 25,000
gallons-per-day capacity or greater. They had a total capacity
of 247,166,000 gallons of freshwater per day. The largest plants
were at Rosarita, Mexico (7-5 mgd); Terneuzen, Netherlands (7.6 mgd)
and Schevchenko, Russia (31.7 mgd). The largest plant in the U.S.
was the facility in Key West, Florida (2.6 mgd).
About 98 percent of the desalination plants used the flash distillation
process employed by the Key West facility and most were constructed of
similar materials. The major difference between the Key West facility
and other desalination plants was the source of seawater. The Key
West plant obtained its seawater from deep wells rather than from
the sea. They benefited from this by eliminating biological fouling
problems and obtaining water of uniform, low temperature but were
penalized by the corrosive action of hydrogen sulfide present in
the well water.
Within the next five years the Office of Saline Water predicts world
capacity for desalination will quadruple (Fig. 1). Desalination plants
of one billion gallons of freshwater per day capacity have been designed.
The ecological impact of the effluent from these plants requires immediate
consideration as engineering plans (including effluent discharge designs
and materials for construction) are already nearing completion. Small
modifications in outfall design and forethought about the location of
these outfalls may make significant differences in the ecological impact
of the wastes. Since heavy metals produced by internal corrosion
endangers marine biota, careful selection of materials for various
portions of the plants can have vital importance on the biological impact.
In 1968, Westinghouse Ocean Research Laboratory began preliminary surveys
on the biological impact of the desalination plant at Key West, Florida
(Clarke et al 1970), with support of the Federal Water Pollution Control
Administration (now the Environmental Protection Agency). Their findings
prompted a more extensive biological investigation to quantify the bio-
logical impact and determine which constituents of the effluent were dele-
terious. Therefore, in July, 1970, Westinghouse Ocean Research Laboratory
13
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PROJECTION OF FUTURE WORLD-WIDE, CUMULATIVE DESALTING PLANT
CAPACITY IN OPERATION OR UNDER CONSTRUCTION
62
66 67 68 69 70
CALENDAR YEAR ENDING
FIG. 1 PROJECTION OF FUTURE WORLD-WIDE DESALTING USE,
(FROM SACHS 1969)
14
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began the first large-scale biological investigation of the impact
of desalination plants on the marine environment.
Previous researches (Le Gros et al 1968, Zeitoun et al 1969a) had
surveyed the literature for theoretical effects of heated brine
effluents and high levels of trace metals. Some experimental laboratory
studies and analyses of effluents had been conducted on the effects of
copper on the marine environment (Zeitoun et al 1969b). These works
contain excellent summaries of previous studies relating to biological
tolerances for excessive heat, salinity, and copper.
The desalination plant at Key West is owned by the State of Florida
and managed by the Florida Keys Aqueduct Commission. It supplies
the City of Key West with about 2.4 million gallons of freshwater per
day. Additional water is pumped from the mainland of Florida to this
island community. Since the facility is located in subtropical areas,
the effects of added heat and salinity were expected to be more pronounced
here than in cooler waters. Since the plant was constructed by the
Westinghouse Electric Corporation, it was also felt that cooperation
between the plant operators and the researchers would be good, thus
facilitating the research.
The objectives of the research program were to determine the biological
impact of the desalination plant effluent, to define the most toxic
elements of the discharge, to develop predictive capabilities on effects
of additional thermal, heavy metal, and organic loading of Safe Harbor,
and to establish possible methods for management of such stresses.
In addition to reaching the planned objectives, Westinghouse Ocean
Research Laboratory assisted the Florida Keys Aqueduct Commission and
Westinghouse Electric Corporation in planning actual corrective measures
to improve the water quality of the effluent.
The study showed copper discharge to be in excess of safe biological
levels. Reasons for the excessive corrosion were sought and engineering
methods were designed to overcome the corrosion problems. Westinghouse
Electric Corporation donated the engineering time involved in the corrective
measures, but the cost of the actual changes were still great. The
following steps were taken beginning in 1971:
1. Large copper-nickel separatory trays were removed from
the deaerator and temporarily replaced with wood screens
(June, 1971). Stainless steel trays have been ordered
and will replace the remaining copper-nickel trays by
the spring of 1972.
2. An entire tube-bundle (1,200 tubes, 110 feet long) was
removed and replaced with titanium tubes (November, 1971).
3. A new boiler was installed to prevent frequent shut-down
15
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periods for boiler maintenance. A building was constructed
around the new and the old boiler to reduce corrosion
problems, (December, 1971).
4. The capacity and efficiency of the decarbonizer will be
improved to increase aeration of the feed water and
reduce H_S to negligible levels.
To further reduce environmental effects of the facility, washings
from the boiler will be dumped into a large excavated holding pond and
not into the marine environment.
16
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SECTION IV
MATERIALS AND PROCEDURES
DESALINATION PLANT OPERATION
The desalination plant is a 50 stage flash-evaporator type (Fig. 2).
Its general operation has been described by Clarke et al (1970) and
Popkin (1969). The plant draws saline water from three 120 feet deep
wells, acidifies it with H_SO, to remove carbonates, adjusts the pH
with NaOH, heats and degasses the water, and passes it through a series
of 50 chambers with ever diminishing pressures. As the hot water enters
each chamber it boils violently, cools slightly, then flows to the next
chamber where an increase in vacuum causes it to boil again.
The steam created by the boiling brine is condensed on cooling tubes,
drips onto product trays and is then pumped through a filter and into
the city water system. Brine flowing through the system is recycled
many times with only a portion drawn off each cycle as brine blowdown.
The blowdown and a smaller volume of cooling water (called reject water)
empty into an open sump and flow through a three-foot pipe into Safe
Harbor canal. The discharge is located on the upper portion of the canal
wall about three feet under the surface of the wafer.
CHARACTERIZATION OF THE EFFLUENT
The effluent was monitored in three ways; by continuous recording instru-
mentation, by measurements and calculations based on the operating charac-
teristics of the plant, and by periodic manual sampling and laboratory
analysis of the effluent.
Sample water for continuous monitoring was drawn from the effluent pipe
by a nonmetallic pump and passed through a bubble remover reservoir to
continuous recording instrumentation. Temperature was recorded from a
thermister probe located in the effluent pipe and conductivity from a
probe in the bubble removing reservoir. The pH was measured in a flow-
through cup in a small laboratory facility adjacent to the desalination plant,
Copper was measured by a flow-through Hach Chemical Company, Inc., Model
2006 copper analyzer. Temperature, conductivity, and pH data were
processed by a Hydrolab, Inc., battery-operated Hydrolab IV system.
Throughout the study continuous monitoring instruments were a problem.
The copper analyzer suffered from clogged capillaries and electronic
17
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OWNER - FLORIDA KEYS AQUEDUCT COMMISSION
ENGINEERED, DESIGNED AND CONSTRUCTED BY
WESTINOHOUSE WATER PROVINCE DEPARTMENT, ORANGE. CALIFORNIA
FIGURE 2 SCHEMATIC DIAGRAM OF THE OPERATION OF THE KEY WEST DESALINATION PLANT
-------
failures. Almost a year went by before it was properly corrected and
began consistantly producing reliable results. The Hydrolab IV temperature
and conductivity modules worked well but the pH probe suffered from large
electrostatic charges generated by the seawater flowing through the
desalination system. The pH measurements were, therefore, made twelve
times daily by testing a sample of the effluent on a Beckman laboratory
pH meter.
Independent samples of well water and effluent were taken twice a week
during normal field collections. These samples were analyzed along with
the samples from the harbor (see below) for temperature, salinity,
alkalinity, and total copper. The effluent was also sampled quarterly
for emission spectrographic and atomic absorption analyses of the major
elements. Additional samples were taken periodically to examine heavy
metal discharge following periods when the plant had been closed for
maintenance and descaling.
Every two hours, the plant operators recorded maintenance data for the
desalination plant including temperatures, water flows and pH readings.
These measurements provided the most reliable data on the long-term
operation of the facility and were the source of the averages presented
in the report showing long-term trends in parameters of the effluent.
Samples taken and analyzed concurrently with the field station collections
were used for estimation of the percent effluent at the stations and as a
cross-check for the data calculated from maintenance records.
Salinity, temperature, and pH were calculated from the maintenance books.
Since salinity measurements of the blowdown were not taken by the
plant operators, they were calculated by comparing the total water
flowing through the system, the amount of freshwater being produced, and
the salinity of the well water. Well water salinity averaged 38.266 o/oo
with a standard deviation of only 0.01 o/oo.
Using the observed salinity of the well water (S' ), the total amount of
seawater pumped (T), and the amount of water produced (P), the salinity
of the effluent (S ) was calculated as:
6
T
S = S
e w
T P
Temperature of the effluent was recorded by laboratory-grade glass
thermometers at the point of discharge into the open sump. Two separate
readings were taken; one for the stage 50 brine (brine blowdown temperature)
and one for the reject water. Since the volume of the reject water was
known to be one third the volume of the brine blowdown (under normal
operating conditions) the temperature of the combined effluent (T ) was
calculated from the temperatures of the brine blowdown (Tfe) and the reject
water (T ) using the formula:
T + T
T = 2b +
e - -.
19
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Data from these calculations were compared with direct measurements of
the combined effluent and found to be accurate to 0.1°C and 0.05 o/oo
salinity.
STATION LOCATIONS
Figure 3 shows the location of stations in Safe Harbor. Stations 10A
and 10B were used as controls and were located in another basin about
two kilometers east of Safe Harbor (Fig. 3). They were located on a
vertical rock wall adjoining undeveloped military property. Hydrologic
conditions were similar to those in Safe Harbor but there were no
effluents discharged into the control area.
Before selecting locations for the stations a survey was made of Safe
Harbor and basic characteristics of the effluent discharge. This survey
showed that the effluent did not mix uniformly in the harbor and that a
dense, hot layer of effluent-laden water formed a well defined stratum
throughout the harbor (see Section V). Stations were installed in and
above this stratum on the vertical rock walls. The shallower stations,
8 to 10 feet (2.4 to 3.0 meters), were designated "A" stations and were
relatively free from effluent from the desalination plant. The deeper "B"
stations, 24 to 26 feet (7.3 to 7.9 meters), were exposed to the effluent
and were placed directly below each "A" station. Biological activities at
the stations are listed in Table I and depicted in Figure 4.
EFFLUENT DISPERSION
To interpret the biological data, it was essential to determine the
distribution and concentration of effluent in the receiving water.
Hydrographic measurements, sediment analyses, and observations of dye
dispersion by divers provided the required effluent dispersion data.
Hydrographic measurements included temperature, salinity, copper, dissolved
oxygen, alkalinity, and currents. Since the purpose of these measurements
was to determine the amount of effluent present at the biological field
stations, the technique of collection and analysis of the data was designed
to eliminate ambient fluctuations and to calculate the percent effluent
at the stations. This was accomplished by comparing characteristics of
the water at the station with similar data from the discharge and the
mixing water and calculating, by a simple dilution formula, the percent
of effluent. Both conservative (salinity and copper), and semi-conserva-
tive (temperature) measurements were used for determinations.
If (£') represents the percent effluent at the station, (P ) the parameter
measured at the station, (P ) the same parameter of the mixing water, and
(P ) the same parameter of the effluent then:
e
20
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FIG. 3 PHASE II STATION LOCATIONS IN SAFE HARBOR, STOCK ISLAND, FLORIDA KEYS
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TABLE I
BIOLOGICAL STATION SUMMARY
Activities in and above effluent stratum. Shallow stations are "A"
series, deeper stations "B" series.
STATIONS (Both A and B)
123^56789 10
Meter Square Quadrats xxxxxxxxxx
(Monthly)
Foratninifera Collections
(Quarterly)
Biomass Collections
(Quarterly)
In situ Bioassays
(Crabs, Echinoids, Thdlassia)
In situ Bioassays
(Ascidians, Gorgonians)
Settlement Panels
(Monthly)
Diatometers
(Bi-weekly)
xxxxxxxxx
X X
X X
XXX
XXX
Transects:
(Monthly)
Plankton Tows;
(Monthly 100
meters long)
Tl: Along desalination plant sea wall.
T2: Along City Electric plant dock (about 300 feet
[91.5m] north of the desalination plant sea wall).
PI: Along desalination plant wall at 28 feet (8.5m).
P2: Along desalination plant wall at 6 feet (1.8m).
P3: Along eastern edge of turning basin at 6 feet (1.8m).
Pk: Along eastern edge of turning basin at 28 feet (8.5m)
22
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FIG.
4 SCHEMATIC OF BIOLOGICAL STATION INSTALLATION NEAR THE TOP OF A VERTICAL CANAL WALL. (B) BIOMASS SAMPLE
AREA, (Q) 1m2 QUADRAT, (T) TRANSPLANTED THALASSIA (SEA GRASS), (A) TRANSPLANTED ASCIDIA (SEA SQUIRTS),
(G) TRANSPLANTED PTEEOGORGIA (SEA WHIPS), (M) SEDIMENTATION JARS, (S) MENIPPE CAGES (STONE CRABS),
(E) LYTECHINUS CAGES (SEA URCHINS), (D) DIATOMETERS, (P) SETTLEMENT PANELS IN PVC HOLDER.
-------
E = st m x 100
P - P
e m
Thus, if the salinity of the effluent was 50.00 o/oo, and the receiving
water had a salinity of 35.00 o/oo and Station 3C had a salinity of
36.00 o/oo, the percent effluent at 3C was:
36.00 - 35.00
50.00 - 35.00
This technique eliminated seasonal fluctuations and made measurements of
the influence of the desalination plant comparable all year. It had
some disadvantages, however. Percent effluent could only be determined
when the plant was operating while the data were being collected. During
the months when the plant was operating sporadically, it was difficult
to obtain many estimates of the concentration of effluent at the stations.
Studies showed it took between 24 and 48 hours for the effluent to
reach all stations in the harbor and a similar time for the effluent
to disperse. During these times, the percentage of effluent was
either increasing or decreasing at the stations and a sample at any
one station would not necessarily be representative of effluent
levels during these sampling periods. Therefore, data taken within
48 hours following a start-up period gave relatively unreliable
results, especially for more distant stations.
Since discharging effluent was required for calculation of the percent
effluent, data taken immediately after the plant shut down could not
be incorporated in the monthly averages even though some effluent was
still in the harbor. If the plant shifted its mode of operation, the
shift was not reflected in the more distant stations for 24 to 48 hours
and the calculated percent effluent was correspondingly wrong. When
the plant operated continuously (as it did in the first portion of the
study) the method worked exceedingly well. During months when the
operations were sporadic and unstable the averages were less reliable.
A final problem was related to short-term differences that occurred
between measurements made in the harbor and on the surrounding grass
flats. During periods of rapid temperature or salinity changes, the
characteristics of the water in the shallows changed more rapidly than
in the deep water of Safe Harbor (due to the ratio of surface area
relative to volume). Thus, water at the shallower stations occasionally
had different characteristics from that which mixed with the effluent
at depth. Because of this shallow-water effect, it was possible to
obtain negative values for percent effluent present, at the shallower
stations after heavy rains or when there was a rapid change in
temperature.
Despite these difficulties, the method worked within acceptable limits.
Figure 8 shows the mean monthly percent effluent at a station near the
discharge with 90 percent confidence limits of the mean, and Figure 27
24
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shows the fifteen month mean percent effluent at all Safe Harbor stations
with 90 percent confidence limits. While the percentage of effluent was
not within the accuracy expected for laboratory bioassays, it was generally
within + 1 percent and was adequate for in situ bioassay work.
The duration of the average percentage of effluent had to be included in
correlations of biological and physical data. An effluent exposure index
was devised by multiplying the average percent effluent times the number
of days that average was present (i.e., the number of days the plant was
operating during the period of exposure).
To increase the validity of the hydrographic data, all stations were
sampled within two hours of taking the effluent and mixing water samples.
Generally, Stations 1 through 3 were sampled first followed by the
effluent samples, then the remaining Safe Harbor stations. Station 10,
the control station, was sampled last. Physical and chemical measurements
were taken on Mondays and Thursdays.
Water samples were collected adjacent to each of the twenty biological
quadrats in a two-liter Plexiglas Van Dorn bottle manufactured by Hydro
Products (Model No. 120). Sub-samples, used for salinity and alkalinity
determinations, were decanted into polyethylene bottles having poly-seal
stoppers and analyzed the same day they were taken. Sub-samples for dis-
solved oxygen measurements were placed in standard 300 milliliter BOD bottles
with ground glass stoppers and immediately fixed with manganous sulfate,
alkaline iodide, and sulphamic acid. Sub-samples for copper analyses were
placed .in aged polyethylene bottles and fixed for later analyses with two
milliliters of Baker analyzed hydrochloric acid.
Temperature profiles were taken at each station by lowering a Yellow
Springs Instrument Company Model 437A telethermometer from the
surface to the bottom and recording temperatures to 0.1°C at two
feet (0.6m) intervals. The telethermometer was calibrated with two
Kahl Scientific Instrument Corporation thermometers and found accurate
to within + 0.1°C.
Salinity was determined with a Bisset-Berman Hytech Model 6220 salinometer.
Oxygen determinations were made using a Hach Chemical Company oxygen kit.
The powdered reagents for this kit were eminently practical, especially
when adverse weather conditions made handling the samples difficult.
Phenylarsene oxide supplied by Hach Chemical Company was used in the
laboratory titrations.
Alkalinity was measured by a Hach Chemical Company alkalinity kit.
Alkalinity was obtained directly as equivalent CaC03 in grains per gallon
from burette readings at the end of titration (1.0 grain/gallon - 17.118
mg/liter or 0.34205 milli-equivalents of hydrogen ion per liter).
Copper analyses were made using the neocuperoine technique of Alexander
and Corcoran (1967) summarized in Appendix A.
25
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In situ, rapid determinations of effluent dispersion were made
utilizing the unusual temperature inversion associated with the
effluent stratum. Normally, temperature gradients decrease with
depth (Sverdrup et al 1942) and thermoclines generally have colder
water underlying warmer water. The hot, saline effluent, however,
formed the reverse situation with warmer water under cooler water.
This peculiarity enabled rapid identification of the effluent even
at some distance from the plant. It could be detected easily in
temperature casts with the electric thermometer and could also be
felt by SCUBA divers. The surface of the temperature inversion was
sufficiently well defined that a diver could swim above it and feel
the hot water with his hand. The rapid density change also caused
a visible, shimmering layer because of changes in the refractive
index of the water.
On several occasions, effluent distribution throughout the harbor
was plotted by divers swimming along the top of the submerged
effluent stratum. In the first portion of this study, Rhodamine B
dye was added to the effluent and its distribution traced by divers
in the receiving water. This enabled analysis of the flow of effluent
into the system and showed a self-insulating mechanisms which is
described below.
Thermal differences also enabled instantaneous analysis of the distri-
bution of the effluent by use of a Westinghouse thermister net. The
instrument consisted of fourteen cables deployed in the canal and
connected to a single control unit with a three-dimensional light
display. At the points indicated in Figure 5, the cables were connected
to five thermisters buoyed at five-foot intervals from the bottom up to
a depth of ten feet (3m). One strand (#5) continued to the surface to
give data above the ten-foot level. All the cables were connected to
a tie-down system so the array could be lowered to the bottom when not
in use. Although normal boat traffic carried less than ten feet (3m)
draft, occasional vessels drawing eighteen feet (5.5m) entered the
canal. In addition, tugs and fuel barges on occasion tied up to the
dock at the desalination plant which could have damaged the array.
Each of the 72 thermisters was represented by a small light bulb in a
scale model of the canal. When the single control dial was set at a
particular temperature all of the lights representing thermisters above
that temperature lit up. By sequentially changing the dial setting, all
of the isotherms in the canal could be viewed three-dimensionally. With
the dial set at a particular temperature, an isotherm could be followed
over several hours or days. In this way, one could watch the hottest
portion of the effluent move through the canal as the plant began
operation or as tides or winds shifted.
Initially, the cables were set in a rectangular grid pattern. This
pattern was changed to provide greater coverage of the canal, particu-
larly along the eastern portion, as this arrangement was more repre-
sentative of the general movement of the stratum under normal conditions.
The final arrangement, shown in Figure 5, provided readings along a
26
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FIG. 5 LOCATION OF THERMISTER STRANDS IN SAFE HARBOR CANAL. FIVE THERMISTERS EXTENDED FROM THE BOTTOM TO A
DEPTH OF TEN FEET IN FIVE FOOT INTERVALS. STRAND 5 CONTINUED TO THE SURFACE.
-------
700-foot (213.4m) portion of the eastern half of the canal and a
450-foot (137.2m) portion of the western half.
The dispersion of effluent was also examined by analyzing copper
concentrated in the sediments. Duke et al (1966) and others have
shown that sediments concentrate trace elements from seawater. Since
the effluent had more copper than ambient water, it followed that
sediments exposed to the effluent would be correspondingly higher in
copper than sediments not so exposed. Further, sediments are contin-
ually depositing and would bury older sediments and leave a continuous
record of copper loading in the muddy bottom which could be traced back
to conditions before the desalination facility was built.
Sediments were collected from 150 different locations in and around
Safe Harbor. The samples were collected by SCUBA divers using Whirl-
Pak polyethylene bags. These containers are inexpensive, compact, and
have a wire rim at the opening which serves as a scoop and as a method
of sealing the bag. Each sample was taken by opening the bag at the
point of collection and carefully scooping up the surface layer of
sediment (less than 1 cm in depth). Four separate sub-samples were
taken per bag from each area to provide a composite sample of a larger
bottom area. These samples were frozen for later analysis of total
copper and foraminifera.
Core samples were taken at four locations to examine the history of
copper levels back to before the plant was constructed. PVC pipe,
three inches (6.4 cm) in diameter and three feet (1m) long, was used
as the coring device. It was driven into the sediment, capped, and
removed. The mud core was extruded with a piston and split in half
longitudinally using a thin stainless steel knife. The different
strata were noted for age determination later and sub-samples of the
core were placed in Whirl-Paks for copper, nickel, and foraminifera
analysis. The strata were aged using known data from the history of
the construction of Safe Harbor, sedimentation rates from jars
placed at all the stations, and by measuring the percentage water
content in the upper layers of the sediments.
Safe Harbor is entirely man-made. Const-ruction of the harbor was
carried out over approximately ten years as shown in Figure 6. When-
ever a bulkhead was installed or a portion of the harbor dredged for
fill, course sediments were produced which formed strata clearly different
from the normal fine sediments deposited in the basin. Coarse sand strata,
therefore, offered useful datum planes in core samples for checking cal-
culated ages.
The level where the coarse sediment left by the original construction
of the harbor canal and the sediment which settled later is clearly
deliniated by the microscopic appearance of sediment particles and by
the onset of seasonal cycles which have left numerous strata of varying
tones of grey. The depth of this level in core samples demarcates the
total amount of sediment which has accumulated since that portion of
the canal was built.
28
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1951 1952 1952
FIG. 6 DATES OF DREDGING AND FILLING IN SAFE HARBOR.
-------
Compaction of the sediment in the core, however, was not uniform; the
sediment near the core's surface contained much more water than the
older, deeper sediments. By measuring the volume of water in succes-
sive layers of cores frozen immediately after collection, a correction
was made for the changes in sediment density and a theoretical sedimen-
tation rate calculated. This deposition rate was compared to sediment
accumulated monthly in glass jars at the harbor stations and to coarse
sand deposits in the sediment caused by dated dredging and filling
activities.
A layer of coarse sand 5.25 inches (13.33cm) below the existing surface
of the sediment near the desalination plant corresponded well to the
calculated depth of sediment that should have deposited since the
desalination plant sea wall was constructed in 1967.
BIOLOGICAL INVESTIGATIONS
Two approaches were used in the design of the biological work. The
major emphasis of the biological program was in situ investigations
of the effects of the desalination plant effluent. Laboratory bio-
assays were conducted to isolate the more toxic features of the
effluent, but were strictly an aid to interpreting the in situ data.
The harbor itself formed the basis for a large scale toxicological
study. Three lines of investigation were used to take advantage of
this opportunity; data were collected from selected quadrats and
transects, new surfaces for the settlement of diatoms and larger
organisms were examined, and selected organisms were transplanted to
sites where effects of the discharge on individual specimens could
be followed.
QUADRAT AND BIOMASS SAMPLES
One-meter square quadrats were roped off at each of the twenty stations.
To achieve comparable data, the stations were set on the vertical cal-
carinite walls of the canal area; one quadrat near the top of the wall
and one near the bottom. Divers recorded the organisms present in each
quadrat once a month. Near these quadrats divers took monthly O.lm2
samples of the substrate for biomass analysis. Species found at each
of the stations were tabulated both from quadrat and biomass collections.
Diversity was calculated using Margalef's proposed index (Margalef
1957). This index was selected since the mathematical weighting of
the sample is related to the concept of entropy in the third law of
thermodynamics. It satisfactorily accounts for species present and
30
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their relative abundance without being heavily biased by the large
numbers of serpulids which inhabited many of the stations. The
Margalef diversity index can be designated as an index of dominance
diversity (Whittaker, 1965) since it indicates the numerical percentage
composition of the species present in the sample (Sanders 1968).
The more species are represented by equal numbers of individuals
the more diverse the fauna. When the numbers of individuals in the
various species differ greatly (i.e., when some species greatly
dominate the sample) the sample is less diverse.
Dominance diversity, therefore, is a measure of how equally or
unequally the species divide the sample. The formula for Margalef's
diversity index (Margalef 1957) is:
I = Z P.lnP.
i t
Where I is the dominance diversity index, P. is the number of organisms
in species i divided by the total number of^organisms in the sample,
and In P. is the natural logarithm of P..
The structure of the animal populations in the quadrats were compared
with each other and ranked by similarity using the Bray and Curtis
(1957) similarity coefficient modified of Pearson et al (1967).
The prominence value (PV) of Pearson et al (1967) was changed slightly
using the formula PV = AF rather than PV = A(F)l/2 where A is the
average number of individuals of a particular species and F is the
frequency of occurrence. Thus, if an organism had an average
abundance of 500 specimen? per square meter but was present only
twenty percent of the time, its prominence value would be 100. Since
this figure represents the average abundance of the organism with its
absence during any given month included in the average as 0, it was
felt more realistic and meaningful than the arbitrary use of (F) '2.
Once prominence values were calculated for each species present at
the station, these were summed. The stations were compared to each
other by determining the minimum percentage of individuals of each
species shared in common using the formula given by Pearson et al
(1967):
S = 2W/(a + b)
Where S is the similarity index, a and b are the sums of the promi-
nence values of the two stations being compared, and W is the sum of
the smallest prominence values for each species shared in common.
This index varies from 0 when no two species are shared in common
to 1 where both stations have identical population structures.
Quarterly samples of sediments were collected from all stations for
analysis of foraminifera (shelled, microscopic protozoans). Divers
31
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scooped about 100 cc of the upper 1 cm of sediment Into Whirl-Pak
bags and these were preserved in alcohol.
Each sediment sample was placed in a 100 ml graduated cylinder and
allowed to settle two hours before its volume was recorded. The
sample was then wet sifted through a U.S. Standard 63 micron mesh
sieve, replaced in the 100 ml graduated cylinder and the new volume
recorded. After transfer to a petri dish, an aliquot was spread
evenly on a microscope slide until there was only a single layer of
sediment. This was examined wet under a 40X compound microscope
with transmitted light. A mechanically operated stage permitted
the entire slide to be examined systematically.
The four major species of foraminifera were sorted and a fifth cate-
gory, "others" , recorded. Live specimens, characterized by proto-
plasm inside the chambers, were recorded separately from dead speci-
mens. Aliquots were examined until over 100 live specimens were
recorded. The volume of each aliquot was measured in a water-filled
1 cc graduated cylinder calibrated to 0.01 cc.
The number of live specimens in 1 cc of the original sample was
calculated from the formula:
T L V
L = o s
o
V V
a o
Where L = live foraminifera per cc of original sample, L = number of
live specimens counted, V = volume examined, V = volume of sifted
sample, V = original volume.
TRANSECTS
Each month, divers swam two transects; one along the desalination
plant sea wall, and the other along the pilings of the City Electric
property 393.6 feet (120m) farther into the harbor. Distributions of
lobsters (Panulirus argus), stone crabs (Menippe mercenaria), sea
squirts (Aseidia nigra), bryozoans, serpulids, barnacles, and macro-
scopic algae were recorded on plastic slates. Observations included
the entire wall of the canal from the inter-tidal zone to the soft
sediment about twenty feet from the surface. To equate the data
collected on these transects, they were reduced to numbers of organisms
per one hundred feet (30m) of sea wall.
In addition to the transects in Safe Harbor Canal, a series of tran-
sects were made both east and west of the turning basin. Ten 100 m^
transects were made 100 meters apart beginning on the edges of the
turning basin as shown in Figure 35. The transects were made using
32
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a 50-meter nylon line stretched and anchored at both ends along
the transect path. Two one-meter long wooden dowels were attached
at one end with eye bolts to the line. Divers swam the length of
the nylon line with the dowels held at right angles to the line
and at the level of the base of the turtle grass. Echinoids
were counted as the dowels turned them over along the 50m transect.
Lyteohinus and Tripneustes, with similar ecological and morpho-
logical characteristics, were counted together and Diadema was
counted separately.
PLANKTON TOWS
Four plankton tows were taken monthly; two at Station 9 in the
turning basin and two along the desalination plant sea wall. At
both locations one tow was taken at 6 feet (1.8m) depth and another
at 28 feet (8.5m). A O.lm plankton net with 50 meshes per cm (125
per inch) was towed 100 meters by a SCUBA diver, thus filtering
10m of water. At the end of each tow the net was sealed off at
depth and the sample transferred to a Whirl-Pak and preserved with
alcohol. The entire sample was later reduced to 10 ml by allowing
it to settle in a graduated cylinder for four hours and siphoning
off the supernatant fluid. The remaining sample was then mixed thoroughly,
sampled, and the plankters counted on a Palmer counting cell. Data
were recorded as numbers of cells or zooplankters per m of original
sample.
To determine effects of effluent on plankton populations, the tows
at Station 9 were used as controls for the tows made in front of
the desalination plant. The two shallow tows and the two deep tows
were compared with each other and the number of plankters found at
the desalination plant expressed as percentages of the Station 9 tows.
Station 9 (600 meters south of the desalination plant) was similar,
topographically, to the canal in front of the plant discharge. Since
water from Station 9 generally moved into the harbor the plankton
population should have been similar at both locations. Differences
between Station 9 plankton populations and the canal were attributed
to effluent effects. Tows were made in front of the desalination
plant with effluent present and after the plant had been shut down
for several days for conformation of the similarity of plankton
populations.
SETTLEMENT PANELS AND DIATOMETERS
Wooden settlement panels and glass diatometers were placed at selected
stations in Safe Harbor and in the control area and recovered at
periods ranging from two weeks to two months. The panels were
settled by organisms which survived the effluent during larval,
33
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metamorphosing, juvenile, and young adult stages. Settlement panels
were valuable biological integrators which provided an easily
quantified sample. Since the surface area and time exposed were
constant, various parameters, including species diversity, density,
and growth, could be determined and compared directly between stations,
Settlement panels were 0.05m2 squares (about 9 inches x 9 inches)
of 1/4 inch untreated plywood. They were attached to PVC racks at
Stations 2A, 2B, 3A, 3B, 3C, 5A, 5B, 6A, 6B, 7A, 7B, 10A, and 10B.
Each rack held three squares and each month two were collected and
two replaced. By rotating one panel, each monthly collection had
one panel exposed for thirty days and one exposed for sixty days.
Panels were collected in individual labeled polyethylene sacks and
analyzed the same day.
Settlement panels were examined for larger invertebrates and these
counted and recorded as to their position on the top or bottom of
the panel. A 0.005m2 plastic grid was then randomly placed on the
panel and the smaller organisms counted. During some months,
serpulid settlements were so thick that it was not practical to
count the whole 0.005m2. During these periods, five 1cm2 sub-
samples were marked off and the serpulids counted under a dissecting
microscope.
Diatometers consisted of five glass microscope slides held in a
PVC rack at Stations 3A, 3C, 7A, 7B, 10A, and 10B. Benthic diatoms,
protozoans, and a variety of invertebrates settled on the slides.
Every two weeks the slides were collected and replaced with new ones.
The organisms on the exposed slides were counted under a compound
microscope using a grid divided into 0.01mm units. Diatom and proto-
zoan species and numbers of individual cells were recorded. Other
organisms (i.e., barnacles, serpulids, etc.) were noted as present
or absent.
TRANSPLANTS
To assess the impact of the effluent on individuals of selected
species, specimens were transplanted into particular effluent regimes
and their survival and growth noted. Sea squirts (Ascidia nigr>a) ,
sea whips (Pterogorgia anceps), turtle grass (Thalassia testudimm) 3
stone crabs (Menippe mercenaria), and sea urchins (Lyteohinus
variegatus") were moved from neighboring flats to harbor and control
stations. The first two are filter feeding, attached organisms,
the last two are motile benthic organisms (L. variegatus is herbivorous
and M. mercenari-a is carnivorous).
Previous work (Clarke et al 1970, Chesher, unpublished data) showed
stone crabs were relatively resistant to the effluent and sea urchins
sea squirts, and sea whips were highly sensitive to the effluent.
34
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Since the filter feeders required little maintenance, they were
placed at more stations (2A, 2B, 3A, 3C, 5A, 5B, 6A, 6B, 7A, 7B,
10A, and 10B). Stone crabs and sea urchins had to be confined in
specially built cages and required feeding three times per week,
consequently, they were limited to Stations 3A, 3C, 7A, 7B, 10A,
and 10B.
The sea whip, Pterogorgia anceps, is a common, nearshore, Caribbean
horny coral, which was known to be sensitive to the effluent. Large
numbers of P. anceps were located east of the turning basin in two
to three meters of water. They were pried loose from the substrate
and mounted in PVC holders. Two-foot (60cm) lengths of half inch
diameter (1cm) PVC pipe were split longitudinally for about three
inches (8cm) and the bases of the sea whips forced into the splits.
The elasticity of the PVC clamped the stalks firmly enough to hold the
colonies in place. At the designated stations, the free end of a
holder was forced into the sediment or into the coral wall. Two
specimens were placed at each station and divers checked their con-
dition twice a week. Dead colonies were replaced monthly.
Sea squirts (Addict, nigra) are filter feeding tunicates and were
extremely common in the Key West area. Specimens were collected
attached to loose rocks and moved, along with their rocks, to the
biological stations. Five specimens were placed at each station.
Unfortunately, whenever a specimen was bruised or otherwise damaged,
it was almost immediately attacked and eaten by fish at the station.
Because of their susceptibility to predation, they yielded poor data
as transplant organisms.
Turtle grass (Thalassia testud-inim) was also vulnerable to predator
pressure. Because of the dearth of algae and turtle grass near the
Safe Harbor biological stations, herbivorous fish rapidly cropped
transplants to the roots. While the roots survived for a time, the
intensity of fish feeding prevented regrowth and the transplants died.
At the control station, turtle grass survived the transplantation for
the entire study period.
Stone crabs (Menippe mercenaria) were easily maintained in experi-
mental cages but specimens were periodically released by sport divers.
On several occasions the cages were found opened and empty. A sign
reading, "Danger, Poison, U.S. Government Survey, $1,000 fine for
tampering", was placed on the cages and the releases stopped for
several months. There were five stone crabs located at each station.
Three times per week the stone crabs were fed either fish or squid
by SCUBA divers. Missing or dead animals were replaced every month.
Sea urchins (Lyteohinus variegatus) were maintained in individual
cages and fed turtle grass three times per week. Escapes were rare
and sport divers did not molest the cages. Dead urchins were replaced
as they died for the first few months and then every month for the
remainder of the study.
35
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Stone crab and sea urchin cages were constructed from plywood and
steel hardware cloth. They survived eighteen months in the field
and provided additional data on wood boring organisms when dis-
mantled.
Experimental animals were collected from outside the harbor area
by SCUBA divers. To minimize damage to the organisms, they were
handled as little as possible and transplanted to the cages and
holding sites within a few hours of collection. Effects of the
transplantation techniques were evaluated from survival at the
control station (Station 10).
LABORATORY BIOASSAY
Laboratory 96-hr TLm acute bioassays were conducted on the same
species used for the in situ bioassays to determine the relative
toxicity of the fresh effluent from the desalination plant and to
isolate the most toxic features of the effluent. The experimental
design used is shown in Figure 7. The experiments began by conducting
static 96-hr TLm acute bioassays (Doudoroff et at 1951) of fresh
effluent in 50 liter, all glass aquaria. A wide range of effluent
dilutions, plus a control, assured sufficient data points to make the
interpretation valid.
Each dilution contained ten experimental animals and the 96-hr TLm
experiments were run at least twice to obtain replicate data.
Samples of the effluent dilutions were taken daily to ascertain
levels of oxygen, pH, copper, salinity, and temperature in the
aquaria.
The experiments were complicated by the variability in copper content
of the effluent and by the unpredictable operation of the desalination
plant. Obviously, if the plant shut down on a day when effluent was
needed for the bioassays, the experiment had to wait until the plant
resumed operation and became stabilized.
Following the determination of the 96-hr TLm doseage, a second
experiment was set up to isolate the major parameters of the effluent
to determine which parameter was most toxic (Fig. 7). Copper,
salinity, and temperature were independently elevated in normal,
filtered seawater to a level comparable to that found in the 96-hr
TLm effluent dilution. 96-hr TLms were then conducted for these
individual parameters. Salinity was raised by the addition of
artificial dried seawater^salts, copper was raised by the addition of
copper sulphate salts and temperature was raised by thermostatically
controlled, glass protected heating units.
Bioassays on the turtle grass, Thalassia testudinum, were conducted usinp
36
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STEP 1
A series of aquaria containing various dilutions of the effluent in
seawater were set up to determine the 96-hr TLm. Numbers indicate
percentage dilution factors.
STEP 2
A second series was set up to find the most toxic element of the
discharge using the 96-hr TLm dilution determined in Step 1 as a
base. Temperature, salinity, and copper were the three factors
examined.
tsc
TSC
Tsc
tSc
tsC
tSC
tsc
TSC
Tsc
tSc
tsC
tsc
eawater Effluent at Seawater Seawater Seawater Effluent
96-hr TLm w/temp. w/salinity w/copper w/reduced
dilution elevated elevated elevated temperature
96-hr TLm Parameters
T = Temperature
S = Salinity
C = Copper
Ambient Seawater Parameters
t = temperature
s = sal inity
c = copper
FIG. 7 BIOASSAY EXPERIMENTS
37
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s similar analytical approach but a different experimental setup.
Freshly cut, clean, turtle grass was suspended in 500ml Erlenmeyer
flasks. Photosynthetic rates were measured by oxygen,production
monitored continuously by an IBC Model 170 oxygen analyzer. The
samples were stirred by magnetic stirring bars. Illumination was
kept at a constant 1,000 lux using fluorescent lights.
To prevent oversaturation of the sample water with oxygen, the filtered
seawater used during the experiment was scrubbed with nitrogen for one
hour, lowering the oxygen content to less than 1 mg per liter (five
percent saturated). Oxygen was normally low in the effluent and this
did not require treatment.
After a two hour photosynthesis history was obtained for each lot in
filtered seawater, toxicants were added and photosynthesis monitored
for twenty-four hours. Toxicity was measured as the amount of con-
taminant required to lower the photosynthetic rate by 50 percent after
twenty-four hours of exposure (Goldman, 1966, A.S.T.M. 1964, Wetzel,
1966, Clendenning and North, 1960).
GRAPHIC TECHNIQUES
Most of the graphic techniques used in the report are conventional
and need no explanation. To compare numerous data points for the
several stations involved for a complete year's cycle required use
of circular graphs (Fig. 8). While circular graphs are in widespread
use for data recording, they have not frequently been used for data
reporting.
By dividing the graphs into twelve radii, each representing a calendar
month and arranged as the hours on a watch, average monthly data can
be compactly presented. Circular graphs are also useful in presenting
data for comparison of one factor versus another. The shapes of the
polygons formed by the graphs are representative of general trends and
can be visually compared with one another when presented together.
Thus, having data from all stations represented on one page (see Fig.
26, page 78) enables the reader to compare trends from one station to
the next at a single glance. A critical look at Figure 26 yields the
following observations:
1. The percent effluent at the shallow stations
(the unshaded, center portions of the graphs)
is negligible compared to the amount at the
deeper stations (outer portions of the shaded
area).
2. The amount of effluent is relatively constant
at Stations 2 through 6 and erratic at the
more distant stations.
38
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DEC
NOV
JAN
SEPT
AUG
APR
JULY
MAY
JUNE
FIG. 8 MONTHLY MEAN PERCENT EFFLUENT AND THE 90 PERCENT
CONFIDENCE LIMITS OF THE MEAN AT STATION 3C, 73m
(240 FEET) FROM THE DISCHARGE OF THE DESALINATION
PLANT.
39
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3. The percent effluent has decreased slightly at
the stations during the year's cycle.
4. There was more effluent at Stations 2 through 6
than elsewhere in the harbor.
Use of circular graphs also permits presentation of all the monthly
operating data of the desalination plant on a single page (see Fig.
10, page 46), and monthly averages of pertinent ambient conditions
on a single page (see Fig. 11, page 47). The cyclic nature of the
average temperature and salinity and the noncyclic nature of the
depth of the effluent stratum and of copper concentration in the
harbor are clearly shown in Figure 11. Comparison of the shape of
the shaded curves of salinity and the depth of the effluent stratum
shows these two factors follow a similar pattern during the year,
whereas changes in temperature are not reflected in changes of the
depth of the effluent stratum.
40
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SECTION V
SAFE HARBOR
BATHYMETRY
Safe Harbor is a man-made harbor built primarily for the shrimp
boat fleet. It is divisible into four parts; an approach channel,
turning basin, entrance canal, and series of embayments for docking
boats. It was built in several stages between 1950 and 1960 (Fig. 6).
Except for some of the inner basins the harbor was dredged to a depth
of about 30 feet (9m) by shore-operated draglines.
The gently undulating floor of the harbor is covered with fine calcium
carbonate silt and the vertical walls are coral rock encrusted with
various organisms. Figure 9 shows the bottom topography as deter-
mined from fathometer tracings. The average depth of the harbor
and turning basin is 22.6 feet (6.89m). Depths of 35 feet (10.67m)
are found in two of the marina basins and in the turning basin.
Thirty-foot (9m) depths occur in all marinas and along the edges of
the entrance canal from the southern side of the City Electric dock
to the turning basin. All of the 30-foot (9m) deep basins are
surrounded by shallower bottom. They communicate with each other
above the 25-foot (7.62m) level but are cutoff from the open sea by
an 18-foot (5.49m) sill in the channel dredged across the shallow
flats to the south of Stock Island. Thus, the water within the turn-
ing basin and harbor at depths greater than 18 feet (5.49m) circu-
lated poorly.
WATER CIRCULATION
During the study, winds from the southeast moved surface water into
the harbor. Most of this water, and water brought in by the flood
tide, came from flats to the east of Safe Harbor. Current flow in
deep water in the entrance canal was predominantly out of the harbor.
On some spring flood tides, the current reversed on the bottom or
stopped completely. Currents were imperceptible in harbor embayments
at depths greater than 30 feet (9m) and anoxic conditions occasionally
occurred. Surface currents inside the harbor and on adjacent shallow
water flats were wind-driven with little or no tidal influence. Clarke
et al (1970) provide additional wind and current data for Safe Harbor.
41
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FIG. 9 BATHYMETRY OF SAFE HARBOR. DEPTHS IN FEET AT MEAN SEA LEVEL
-------
TIDAL FLUSHING
The total surface area of Safe Harbor was 4.48 million square feet
(0.416 million m2) and its volume was 101.78 million cubic feet
(2.88 million cubic meters). The mean tidal exchange was 1.2 feet
(0.366m) (ESSA Tide Tables, 1970) and thus the mean tidal flushing
was 5.38 million cubic feet (0.15 million cubic meters) of water
per mean tidal cycle or 10.76 million cubic feet (0.3 million cubic
meters) per day. During spring tides, tidal flushing increased to
about 13.45 million cubic feet (0.38 million cubic meters) per day.
SEDIMENTS
Calcuim carbonate silt was 8.6 feet (2.6m) thick in the entrance
canal in front of the desalination plant and only 4.5 to 3.5 feet
(1.4 to l.lm) thick in the inner harbor. Sediments in depths
shallower than 25 feet (7.6m) generally had a covering of white
or brown mud while those at greater depths often had a covering
of black silt; the black color derived mainly from H2S, copper and
iron sulphide. These compounds formed because of poor water cir-
culation in depths greater than 25 feet (7.6m), particularly during
summer when there was strong thermal stratification of the water
column. During the summer months, the water in these deep pockets
was characterized by low oxygen, low temperature, high H2S content,
and high water clarity. Core samples of sediment taken to bedrock
showed horizons of hydrogen sulfide present in the sediments in
the past. This anoxic layer was not present from November, 1970
to May, 1971 and during that time the sediment was light grey.
43
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SECTION VI
PHYSICAL PARAMETERS
DESALINATION PLANT OPERATION
Figure 10 shows monthly averages as well as high and low values for
various operating parameters of the Key West desalination plant.
The total volume of effluent discharged decreased during the study
period as did the number of operating days per month. Effluent tem-
perature averaged 35°C during the entire period. The pH averaged
7 with a range of 3.2 to 8.5. Salinity varied more than other
parameters, averaging between 48.00 and 53.00 o/oo with a range
of 40.00 to 55.00 o/oo. Copper discharge varied between 148 ppb
to 6,515 ppb. It increased from a mean of about 1,000 ppb in
June, 1970 to a mean of 2,656 ppb in January, 1971. In June, 1971
engineering changes drastically lowered the copper output and in
August, copper concentration reached a minimum mean value of 425
ppb. Discharge of heavy metals is discussed further in the section
below on copper and nickel.
AMBIENT CONDITIONS
Temperature, salinity, and copper data from all stations were pooled
to present overall monthly averages (Fig. 11). Temperature steadily
decreased from August, 1970 to February, 1971 then increased again
through August, 1971. Salinity declined in October and November,
1970 reaching a low of 34.60 o/oo in November. From then until
May, 1971 salinity increased to high ambient levels with a peak of
38.00 o/oo in April. During that time South Florida experienced
a prolonged drought with little cloud cover. Lack of precipitation
and long hours of sunshine (also plotted in Figure 11) explain the
high ambient salinities.
EFFLUENT DISTRIBUTION
Distribution of the effluent was studied using Rhodamine B dye,
direct observation while diving, thermal mapping, salinity data,
and heavy metals distributions in the sediments (see Section IV
Methods and Procedures).
45
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FIG. 10 MONTHLY OPERATING PARAMETERS OF THE KEY WEST DESALINATION
PLANT FROM AUGUST, 1970 TO AUGUST, 1971. (MEAN, HIGH, AND
LOW VALUES PLOTTED EXCEPT VOLUME AND OPERATIONAL DAYS.)
TEMPERATURE 32-42°C
SALINITY kO o/oo-60 o/oo
COPPER 0 - 4,000 ppb
EFFLUENT
TOTAL VOLUME 0-2 x 108 GAL/MO. OPERATIONAL DAYS 10-30
Each radius is numbered as the hours on a watch and represents that
month. Values are read from the center to the circumference.
46
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FIG. 11 AVERAGE MONTHLY PHYSICAL PARAMETERS FROM ALL STATIONS IN
SAFE HARBOR FROM AUGUST, 1970 TO AUGUST, 1971.
TEMPERATURE 05 - 35°C)
SALINITY (30 - kQ o/oo)
COPPER CO - 100 ppb)
DEPTH OF EFFLUENT STRATUM
(30-10 FEET)
AT (0 - 0.5)
AS (0 - 1.0 o/oo DENSE SHADING)
HOURS OF SUNSHINE (SO-^O HOURS)
Each radius is numbered as the hours on a watch and represents that
month. Values are read from the center to the circumference.
-------
DISTRIBUTION AT POINT OF DISCHARGE
Dye studies showed two distinct plumes. The majority of the dis-
charge mixed with ambient water and sank to the bottom of the
canal scouring the silt from the canal wall. It fanned out to
form a hot, high-saline layer which spread west and northwest
along the bottom. At the point of discharge, a smaller portion
of the effluent was carried to the surface by entrained air
bubbles. Within 60 feet (18m) the bubbles escaped and the upper
plume sank to lie on top of the layer formed by the lower plume.
A large portion of the upper plume circulated around a group of
pilings adjacent to the discharge pipe and was entrained into the
effluent jet and carried to the bottom.
The effluent was diluted by surface water entrained at the point
of discharge. Since surface water to the north of the discharge
pipe consisted of effluent circulating around dolphin #4, the
majority of ambient water that mixed with the effluent came from
south of the discharge, along the eastern edge of the canal. By
the time the effluent reached equilibrium depth it was diluted
approximately twenty times with ambient seawater.
DISTRIBUTION OF THE EFFLUENT STRATUM
The effluent, after the initial turbulent flow to the deeper water
of the canal, spread throughout the harbor and turning basin. There
was little vertical mixing and the effluent retained its heat and
salinity characteristics throughout the harbor to a point about 600
meters beyond the outer rim of the turning basin. Figure 12 shows
the average increment in temperature (AT) and salinity (AS) associated
with the effluent layer. The similar distribution of the two values
demonstrates the conservation of temperature in the system. Greater
temperature differences were found between points separated six
inches vertically than between points over one kilometer apart hor-
izontally. One rapid survey of the effluent stratum at a depth of
20 feet (6m) showed a temperature of 31.6°C at the inner end of the
canal, 31.6°C directly in front of the discharge, and 31.6°C at the
outer rim of the turning basin. The temperature increased from 30.6°C
to 31.6°C in only six inches at the stratum-ambient water interface.
The effluent layer required constant discharge from the plant to
remain stable. When the plant was operating, the effluent stratum
was insulated in two ways." Because of the sill surrounding the harbor,
the upper layer of water moved out of the harbor faster during ebbing
tides than the lower layer containing the effluent. The most recent
discharge from the desalination plant was less dense than older effluent
48
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1.0
STATION
NUMBER
1000
2000
3000
FEET FROM
DISCHARGE
FIG.12 TWELVE MONTH AVERAGE OF THE RISE IN TEMPERATURE (SOLID LINE) AND SALINITY
(BROKEN LINE) CAUSED BY THE DESALINATION PLANT EFFLUENT AT ALL STATIONS IN
SAFE HARBOR.
-------
due to its higher temperature. Thus, it would lie on top of, and
move over, the older effluent water. Dye studies clearly showed
the formation of this midwater layer of lighter effluent and its
moving out of the harbor on ebbing tides. This layer acted as a
buffer zone and impeded vertical mixing of the deeper effluent.
Internal convection cells within the effluent were also prevented
from mixing with the overlying water. As the hot, high-saline
water came in contact with ambient water the least conservative
parameter, temperature, was the first to change. As heat was lost
the high-saline effluent became denser and sank away from the inter-
face thus slowing further cooling.
When the desalination plant shut down, the effluent stratum dis-
appeared from the harbor within 24 hours. Some of the effluent
water must have persisted longer than 24 hours, however, based on
known flushing rates and the known volume of effluent.
The mean depth of the top of the effluent stratum was 18 feet
(5.49m), the average thickness of the effluent layer was 4.6 feet
(1.4m) and its volume was 20,615 cubic feet (0.58 million cubic
meters). Tidal flushing was only 10,756,080 cubic feet (0.30 million
cubic meters) per day and it is questionable if wind-driven currents
could account for the dissipation of the remaining 10 million cubic
feet. Probably, once the thermal barrier was eliminated, vertical
mixing was accelerated. Some effluent cooled and remained stagnant
in the deeper pockets but the remainder probably mixed with the
surface water. The effluent stratum, however, lost its identity
and was not detectable hydrographically after 24 hours.
The effluent production, including the entrained ambient water, was
about 20 million cubic feet (0.57 million cubic meters) per day which
was ample to reestablish the effluent layer within one day. Once the
layer of 20 million cubic feet (0.57 million cubic meters) was estab-
lished in Safe Harbor, there must have been some 20 million cubic feet
of effluent per day mixing with the ambient water and possibly passing
through the approach channel to deeper water.
Failure to find the effluent beyond 2,000 feet (600 meters) past the
edge of the turning basin indicated it was probably mixing with the
surface water to a point where it was not detectable by the hydro-
graphic methods employed. That some effluent mixed with the surface
water was shown by copper analysis of the sediments of the flats to
the west of the turning basin (where the surface harbor water moves
over the flats under prevailing wind conditions). These sediments
showed much more copper than the upcurrent flats to the east. High
copper levels in shallow water areas inside the harbor (see below)
also indicated presence of the effluent in shallower water.
The effluent stratum was plotted in real time using the Westinghouse
thermister array and was calculated from water measurements taken
twice weekly at all stations. Figure 13 shows the monthly average
50
-------
FIG. 13 AVERAGE MONTHLY DEPTH OF THE EFFLUENT STRATUM AT ALL STATIONS
IN SAFE HARBOR.
The circumference represents the
surface of the water, the center
thirty feet.
6
Each radius is numbered as the hours on a
watch and represents that month.
51
-------
depth of the effluent stratum at all stations separately. These
data are combined for a graph of the total average effluent depth
in Figure 11. The effluent layer became shallower during the study
as its strength, measured by the difference between the effluent's
temperature and salinity and the surface water temperature and
salinity, decreased. Figure 13 shows the average monthly location
of the top of the effluent stratum at various stations. The top of
the layer was shallowest at Station 1 and became continually deeper
out to the stations in the turning basin (Stations 7 and 9). At
Station 8, located seaward of the turning basin in the approach
channel, the effluent was occasionally detected flowing out along
the bottom at a depth of 17 feet (5.2m).
Ambient salinity and volume of effluent discharge apparently con-
trolled the depth and intensity of the effluent stratum. Of all
parameters measured, ambient harbor salinity showed the closest
similarity to effluent depth when the two plots were compared
(Fig. 11).
Total hours of sunshine per month are also plotted in Figure 11,
along with the mean difference in salinity (AS) between the surface
water and the effluent stratum. The two plots are more similar than
those of solar radiation and ambient salinity, particularly in
September, 1970. Hours of sunshine are, of course, related to the
amount of evaporation on the shallow flats adjacent to Safe Harbor
and the consequent changes in salinity. Water from these tidal
flats mixed with the effluent discharged near the surface to form
the submerged effluent stratum.
The effluent stratum received little contribution from freshwater
run-off along the Safe Harbor shoreline. Consequently, increases
and decreases of AS closely approximated the shallow flat salinity
and solar radiation, as well as salinity changes during periods of
high rainfall. During heavy rainfall the effluent layer was rapidly
diluted by low salinity water entrained at the surface and within
about two hours, the upper surface of the effluent stratum began
moving shallower; first, near the point of discharge then gradually
farther along the canal.
Differences between temperatures (AT) at 2 to 4 feet (0.61 to 1.2m)
and of the effluent stratum closely followed ambient temperature.
As the ambient water temperature decreased, so did the difference
between the effluent layer and the water above it (Fig. 11). Figure
14 shows the monthly variation of AT at each station for one year.
The lower AT values and shallower position of the effluent layer at
Stations 1 and 8 indicate these were areas of mixing.
The Westinghouse Thermister array provided instantaneous measurement
of the isotherm distribution in Safe Harbor canal (Figs. 15 and 16)
52
-------
FIG.14 AVERAGE MONTHLY RISE IN TEMPERATURE CAUSED BY THE DESALINATION
PLANT EFFLUENT AT ALL STATIONS IN SAFE HARBOR.
Each radius represents 0 - 1°C when read from the
center to the circumference.
6
Each radius is numbered as the hours on a watch and
represents that month.
53
-------
FIG. 15 ISOTHERMS IN SAFE HARBOR CHANNEL MARCH 12, 1970 FROM 1200 TO 1205 HRS.
SAFE HARBOR CHANNEL - EASTERN POSTION
Ui
-B-
9 THERMISTER
STRINGS
30i
10
DISCHARGE
SAFE HARBOR CHANNEL - WESTERN PORTION
540 FEET FROM
DISCHARGE
DATE
3/12
TIME
1200
TEMP
EFF.
39.2
VOL.
EFF.
4160
TIDE
3
COMMENTS
Plant operation
normal. Wind
S.E. 5-10 knots
5% Cloud
No rain
Tide high at
1020 +0.9'
-------
FIG. 16 ISOTHERMS IN SAFE HARBOR CHANNEL MAY 14, 1971 FROM 1005 TO 1010 HOURS.
SAFE HARBOR CHANNEL - EASTERN POSTION
9 THERMISTER
0-
5-
10-
15
20
25
30-
0
0
0
o
0
28.
28.
27.
29.
29.
5 °
0 o^~~~~~~~~
5 ?— -"•"
0 o
2 o /
o 28-5
— ~-^3^^^
-"""o 29 . 0
/^ o ^~~"~~---^_
x^ . 29.5
o 30.0
0
, — — "
0
0
o
----,
0
0
0
o
0
o
0
0
28.5
28.5
28.5
28.0
29.0
29.0
29.5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
o ^""""•--^^
0
0
0
o
0
160 0
DISCHARGE
SAFE HARBOR CHANNEL - WESTERN PORTION
STRINGS
540 FEET FROM
DISCHARGE
10
0-
5-
10-
15-
20-
25-
30-
o
0
0
0
0
11
0
0
0
•
0
0
12
0
0
0
•
0
o
28
28
29
29
29
.5
-5
.0
.0
.5
13
0
0
0
0
0
U
o
0
0
o
o
DATE
5/1*1
TIME
1005
TEMP
EFF.
39.3
VOL.
EFF.
4150
TIDE
5
COMMENTS
Plant operating
normal ly . Wind
SE 10-15 kts,
cloud cover 10%,
tide high at 1 136
and 1 .7 feet.
-------
FIG. 17 MOVEMENT OF 25°C ISOTHERM IN SAFE HARBOR CHANNEL MARCH 12, 1970 FROM 1220 TO 1730 HRS.
SAFE HARBOR CHANNEL - EASTERN POSTION
9 THERM! STEP,
Ul
Ov
15-
20-
25-
30
0
5
10-
15
20-
25-
30-
o
o
•
0
•
0
1420-
1730
STRINGS
160 0
DISCHARGE
SAFE HARBOR CHANNEL - WESTERN PORTION
540 FEET FROM
DISCHARGE
10 11 12 13
1420
o
o
•
0
o
1530
1730
DATE
3/12
TIME
1220
1320
1423
1530
1630
1730
TEMP
EFF.
39.1
39.3
39.2
39.1
39.1
39.1
VOL.
EFF.
4160
4160
4160
4160
4160
4160
TIDE
3
3
3
3
4
5
COMMENTS
Plant operation
normal . Wind SE
5-10 kts.5% cloud
cover. No rain.
(Tide stages =
3-falling
4=low
5=rising)
Tide range
+0.9 at 1020
-0.3 at 1620
-------
FIG. 18 MOVEMENT OF 29°C ISOTHERM IN SAFE HARBOR CHANNEL MAY 14, 1971 FROM 0900 TO
1900 HOURS CONE TIDAL CYCLE).
SAFE HARBOR CHANNEL - EASTERN POST I ON
10
10-
15-1
20-
25-
30-
DISCHARGE
SAFE HARBOR CHANNEL - WESTERN PORTION
9 THERMISTER
STRINGS
540 FEET FROM
DISCHARGE
11
12
13
14
DATE
5/14
TIME
0900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
TEMP
EFF.
39.3
39.3
39-5
39.5
39.2
39.2
39.3
39.3
39-4
39-5
39.5
VOL.
EFF.
4150
4150
4150
4150
4150
4150
4150
4150
4)50
4150
4150
TIDE
5
5
2 hi
3
3
3
3
3
3
3
4 lo
COMMENTS
Plant operating
normal ly . Wi nd
SE 10-15 kts,
cloud cover 10%,
tide high at 1136
and 1.7 feet, low
at 1912 - 0.4 feet
-------
and permitted following the distribution of the hottest portion of
the effluent stratum for several consecutive hours (Figs. 17 and 18).
Figures 15 and 17 are typical of the isotherm distribution observed
during March, 1971. At that time the effluent stratum was suspended
in mid-water and moved regularly with the tide. Figures 16 and 18
show the typical effluent stratum in May, 1971 extending from fifteen
feet to the bottom of the canal. Tidal influence was small during
the periods of observation.
COPPER AND NICKEL
Copper and nickel discharged from the desalination plant increased
to a maximum in January, 1971 and subsequently decreased until
August, 1971. The copper and nickel came from corrosion in two
areas of the plant: 1) from the first set of monel tube-bundles
receiving the well water directly and 2) from copper-nickel (monel)
separatory screens in the deaerator. Although monel normally is
highly resistant to saltwater corrosion, the combination of heat,
high water velocity, low pH, and excessive I^S caused rapid removal
of copper and then nickel from the metal alloy.
There are five tube-bundles in the desalination plant. Most of the
corrosion, however, occurred in the tube-bundle which received the
raw saltwater supply from the pumps (see Figure 2, page 18). This
water contained 4 to 13 ppm H2S (as normal for the large saltwater
aquifer which underlies the Florida Keys)- After treatment in the
atmospheric decarbonator (aeration and acidification) the brine
passed through the air ejector (to remove excess dissolved gas) and
spilled down into the brine chambers through large separatory screens.
The water, at this stage, had its lowest pH and the highest concen-
tration of hydrogen sulfide. Most of the internal corrosion occurred
at this point. From June, 1970 to June, 1971 the discharge averaged
1,766 ppb copper. Copper in the well water averaged only 56.32 ppb.
Analysis showed the copper in the effluent to be 78.4% ionic, 3.4%
particulate, and 18.2% organically complexed (Table II).
Copper discharge was greatest during periods when plant operation was
not stable and particularly after the plant resumed operation follow-
ing maintenance periods. The ionic analysis of the effluent shown in
Table III was taken on February 3rd and 4th, 1971 following resumption
of plant operation after maintenance. Samples were taken for twenty-
four hours after start-up on February 3rd, 1971. Copper, nickel, and
iron were all present in high concentrations following the onset of
desalination operations. At that time, the salinity was lower than
normal (39.14 o/oo as indicated by sodium levels) and the effluent
did not sink. By midnight, six hours later, the effluent reached a
salinity of 47.59 o/oo and peaked at 54.21 o/oo at 0300 on February
4th, 1971. Thereafter, the effluent continued discharging at its
average value of 52 o/oo.
58
-------
TABLE II
ANALYSIS OF EFFLUENT FROM KEY WEST DESALINATION PLANT
COPPER yg/llt.
Sample #
10/20/70 6 pm
10/20/70 9 pm
10/20/70 12 pm
10/21/70 3 am
10/21/70 6 am
10/21/70 9 am
10/21/70 12 am
10/21/70 3 pm
AVERAGE
PERCENT OF TOTAL
Inorganic Total Particulate Organically
Complexes!
1
1
1
1
1
1
1
1
1
,562
,175
,431
,497
,486
,477
,675
,754
,507
7ft.
.5
.0
.25
.5
.25
.5
.0
.0
.38
ft*
1,925
1,587
1,937
1 ,812
1,837
1,900
2.062
2,312
1,921
.0
,5
• 5
-5
.5
.0
.5
.5
.9
23-
173.
108.
29-
25.
36.
94.
28.
6ft..
3-
5
3
0
8
8
0
0
3
8ft 349-68
.1*% 18. 23
59
-------
During periods of irregular operation when pH adjustments were
being made continuously to the desalination plant to control
scale build-up, copper levels became extremely high. Since the
continuously recording copper analyzer did not read above 2,000
ppb, these changes were not recorded in their entirety and, there-
fore, the duration of extremely high copper discharges is not
known. Effluent samples taken during the bi-weekly water surveys
demonstrated that copper values exceed 6,500 ppb during unstable
operating conditions. When pH was lowered, the amount of copper
discharge increased.
In June, 1971, most of the large copper-nickel alloy separatory
trays were removed from the deaerator section and replaced with
wood trays. After the plant resumed operation, copper levels
decreased to a low of 205 ppb. Table III shows the analysis of
the major ions in the effluent during July. The plant had operated
only twelve hours prior to the sampling and should have been pro-
ducing excessive amounts of copper.
Copper concentrations from July to October varied considerably.
July and August had the lowest copper levels observed during the
fifteen month study period (310 and 426 ppb respectively). In
September, the average rose to 1,024 ppb but levels as low as
250 ppb were common. In October, copper levels reached an average
concentration of 1,119 ppb but were extremely variable with the
lowest concentration being 148 ppb and the highest 5,325 ppb.
In November, the plant closed down for extensive engineering mod-
ifications which would bring about the permanent reduction of
copper discharge. Titanium tubing was used to replace the monel
tube-bundles in the first tube-bundle and a new boiler plant was
installed to minimize shut-down periods because of thermal energy
requirements.
In 1972, the remaining copper-nickel separatory trays were replaced
with stainless steel. Unfortunately, the field work for the study
was terminated in October, 1971 and the results of the retubing
have not been assessed.
Monthly copper concentrations at all stations in Safe Harbor are
plotted in Figure 19. Concentrations of copper were generally
higher at deeper stations (Series B, the denser shaded areas on
the graph) reflecting a higher percentage of effluent present.
In contrast, at Control Station 10, copper concentrations were
generally greater in shallower water than deep. When the copper
discharge was reduced in July and August, 1971, differences in
copper concentrations between shallow and deep stations became
less prominent.
60
-------
Hour of
Sample
6/18/71
1200
1500
1800
1100
0300
0600
0900
Well
B 1 owdown
10/20/71
1800
2100
2400
0300
0600
0900
1200
1500
Na x 10
14.85
15.20
15.60
15.60
15.50
15.80
15.20
1K90
16.70
14.50
14.33
14.35
14.85
14.22
14.35
14.50
14.55
TABLE III
IONIC ANALYSIS OF EFFLUENT
Ca K Sr Cu Ti
Ni
Fe
1740
1820
1850
1840
1850
1880
1810
1430
1980
1780
1740
1740
1810
1700
1730
1740
1770
572
605
610
625
605
620
620
480
605
585
590
577
590
572
577
592
585
540 11 o
550 12 1
560 12 1
560 12 1
555
2 1
565 12 1
550 11 1
430 9 0
600 12 1
542
538
530
545
533
540
540
540
1
1
1
1
1
1
1
1
.95
.1
.1
.3
.3
.2
.0
.05
.2
.50
.50
.55
.55
.40
.30
.55
.50
<0.
<0.
-------
IONIC ANALYSIS OF EFFLUENT
Hour of
Sample
0100
0500
0900
1300
1700
2100
Na
17
17
17
17
17
16
x 103
.40
.20
.80
.00
.40
• 50
Mg
2100
2100
2100
2000
2000
2000
Ca
660
640
660
660
660
650
K
640
630
640
630
630
610
Sr
12.0
12.0
12.2
12.0
12.0
11.8
Cu
2.1
2.3
2.2
2.0
2.4
2.9
Ti
0.1
0.1
0.1
0.1
0.1
0.1
N
1
2
2
2
2
2
i
.2
-3
.2
.0
.4
.9
Fe
0.4
0.1
0.8
0.15
0.3
1.2
7/20/71
0900
1200
1500
1800
2100
2400
0300
0600
15.00
15-30
15.30
15-00
11.60
11.40
12.35
14.60
1810
1850
1850
1800
1420
1400
1450
1800
690
720
720
720
590
535
485
585
565
565
560
550
430
410
440
530
0.40
0.31
0.26
0.20
0.62
0.22
0.20
0.23
10/21/71
Cr (<0.30), Zn (<0.02)
1800
2100
2400
0300
0600
0900
1200
16.40
16.50
16.70
15-30
16.70
16.70
16.40
1980
1980
1980
1780
1980
1990
1950
740
720
790
780
780
780
720
580
588
590
545
590
583
585
0.64
0.40
0.74
0.70
0.50
0.65
0.24
0.60
0.55
0.45
0.30
0.70
0.60
0.35
0.40
5-7
4.4
3.0
2.3
2.2
1.7
2.7
4.2
0.10
0.10
0.16
<0.05
0.05
0.13
<0.05
0.52
0.10
0.70
0.65
0.35
1.1
0.10
Cr (<0.05), Zn (<0.05), Al
Note: All the results are parts per million in original
water as determined by spectrograph and atomic
absorption.
62
-------
FIG.19 MONTHLY AVERAGE COPPER CONCENTRATIONS AT ALL STATIONS.
THE DENSER SHADING REPRESENTS THE LOWER, SERIES B STATIONS.
DURING SOME MONTHS THE VALUES CLOSELY OVERLAP.
Each radius represents 0-150 ppb copper reading
from the center to the circumference.
Each radius is numbered as the hours on a watch and represents that month.
63
-------
Normally, copper concentrations at the "A" stations were similar
to control station concentrations. However, when the plant resumed
operations following maintenance, low salinities and high copper
levels were discharged and high levels of copper contaminated these
shallower stations. For example, at 1600 on January 17th, 1971 the
plant resumed operation after a one week shut-down. On the 18th,
at 0900, water samples were taken at the shallower stations in the
harbor which showed far more copper contamination than during normal
plant operation.
The discharge, at 0900 on the 18th, had a copper concentration of
2,061 ppb. Normally, the "A" stations had close to zero percent
effluent reaching them, but following start-up, 3A had 2.3 percent
effluent calculated from the copper concentration. Station 6A had
2.3 percent and 1A had 1.2 percent effluent. Stations 7A, 9A, and
8B remained close to their normal, low copper values until January
20th when all three stations showed abnormally high copper concen-
trations and effluent levels (3.3 percent at 7A, 2.0 percent at 9A,
and 1.6 percent at 8B).
Average monthly copper concentrations for combined Safe Harbor stations
are shown in Figure 19. Although copper concentration in the effluent
was high for October, 1970 (Fig. 10) the average copper levels in the
harbor were low. This was caused by two long shut-down periods (October
4th to October 12th and October 25th to October 31st), and a single
start-up period. In December, when the plant shut down twice for
extended time periods (December 1st to December 9th and December 19th
to December 26th), there were two start-up periods and copper concen-
trations in Safe Harbor increased over the preceding month. Thus,
resumption of operation after maintenance not only brought about better
mixing of the effluent with the ambient water, but it significantly
increased copper levels in the harbor.
64
-------
SECTION VII
ANALYSIS OF SAFE HARBOR SEDIMENTS
HEAVY METALS IN THE SEDIMENTS
Initial analyses of the effluent showed a significant output of
copper (Table III) from the desalination plant and analyses of
sediments of Safe Harbor showed that copper levels were higher
than normal in the upper layers of sediment (Fig. 20). Since
copper antifouling paints are used on boats moored in the harbor,
it was impossible to determine precisely how much copper was
derived from antifouling paint, how much from the desalination
plant, and how much was originally in the harbor.
Sediment cores were taken by divers to obtain a record of sediments
laid down in the harbor since its construction. Changes in parti-
cle size and hydrogen sulfied deposits left clearly delineated
strata in the sediments. Age determinations of these strata were
made by two independent techniques and cross-checked with measure-
ments of present day sedimentation rates. A graph was prepared
based on these data, showing age in years versus the depth of dif-
ferent strata from the sediment-water interface (Fig. 21). This
graph provided dating information for analyzed samples of various
strata in the cores. Strata were analyzed for copper and nickel
content, species diversity of foraminifera and their population
levels.
Copper and nickel levels increased markedly in the strata layed
down after construction of the desalination plant. In a core taken
from one of the shrimp boat basins (near the center of the middle
shrimp boat basin on the western side of the harbor) at a depth of
32 feet (9.7m), copper levels increased first in 1960 and then again
in 1968, about a year after completion of the desalination plant
(Fig. 22). Nickel levels, closely followed copper levels in the
shrimp boat basin during the 1968 increase. Since the amount of
nickel did not increase in 1960 along with a copper increase of about
470 percent, it can be assumed that the source of copper was from
shrimp boat antifouling paints which leach copper but not nickel
ions. After the desalination plant began operating copper levels
increased another 360 percent (Fig. 22), accompanied by a 270 percent
increase in nickel.
Near the desalination plant, in a core taken 100 feet (32.8m) off the
north end of the cement sea wall in 32 feet (10m) of water, there
was no increase in copper until about one year after the plant began
operation and nickel did not begin increasing until two years after
operation began (Fig. 23).
65
-------
FIG.20 DISTRIBUTION OF COPPER (PPM DRY SEDIMENT) IN UPPER CENTIMETER OF SEDIMENT IN SAFE HARBOR
-------
o
cc
C/5
LU
O
2
> 1968
STATION 3
BAY 2
2345
YEARS AGO (FROM SEPTEMBER, 1970.)
lOfi
FIG.21 AGE OF SEDIMENT LAYERS IN CORE SAMPLES
-------
O
UJ
CO
cC.
a
& e
00 Q.
1200-
1000-
800-
600 -
400 •
200 .
I—
~v
in
1970
1969
1968
1967
Drop in I960
to 43-5 average
for 8 years
C
N
171 average
for 8 years
1966
1965
1964
1963
3456
YEARS AGO (FROM SEPTEMBER, 1970)
1962 ,1961
i '—r
FIG. 22 COPPER (C) AND NICKEL (N) CONCENTRATIONS IN THE SEDIMENT AT BAY 2 FROM 1952 TO PRESENT
-------
5000 4 c
1200
1000
a:
Q
Q.
a.
3
<_>
Q
200 H
0
5 6
YEARS AGO (FROM SEPTEMBER, 19/0)
FIG.' COPPER (C) AND NICKEL (N) CONCENTRATIONS IN THE SEDIMENT AT STATION 3 FROM 1950 TO PRESENT.
165 average
for 12 years
53-2 average
for 12 years
C
-------
Shrimp boat antifouling paint, therefore, did contribute to the level
of copper in the boat basins but this source did not affect the level
of copper in the canal. The desalination plant after starting opera-
tion contributed about half of the copper excess in the boat basin
and essentially all of the excess nickel. The desalination plant was
the source for the excess copper and nickel in the canal.
Sediment samples taken in and around the Safe Harbor area showed that
excessively high copper levels were confined for the most part to the
harbor and turning basin. Copper concentrations about 300 percent above
the historical average, extend 400 feet (122m) west of the turning
basin where the well-mixed effluent water flows out of the Safe Harbor
(Fig. 20).
A similar copper level analysis was performed on sediments surrounding a
desalination plant discharge in the Virgin Islands. The results of
these data showed that the effluent path could be traced using copper
in the sediments even though copper discharge was low and the effluent
floated rather than sank (Chesher, manuscript in preparation).
FORAMINIFERA
The foraminiferan fauna from the various sediment strata was examined
for species diversity and numbers of individuals per cc of dry
sediment. A species list of all Foraminifera found in the cores is
presented in Table IV. Presence or absence of a particular species in
the core strata is indicated as well as the time when the desalination
plant began operating. Several species appeared and disappeared in
the course of time>but there was no marked reduction in the number of
species. In fact, 75 percent of the species present in 1955 were
still present in September, 1970 and the number of species had increased
from 48 in 1955 to 51 in 1970. Some species may have been excluded due
to high copper levels. Note, for example, the distribution of Elphidium
advemm, Pyvo subsphaerica} Rosdlina rosea, Quinquelooulina agglut-inans,
TTilooulina rotunda, and Triloaulina planetaria (Table IV). Fursenkoi-na
mexicania, on the other hand, was found only in high copper sediment
samples. The figure on species diversity (Fig. 24) shows little
similarity to the graphs of copper and nickel distribution (Figs. 22
and 23). It is possible that the initial drop in species diversity
during the second year of the operation of the desalination plant
reflected a period of faunistic adjustment. The decline in species
diversity in the core from Bay 2, however, began well prior to the
construction of the desalination plant and continued unchanged
through the initial period. Probably the fluctuations in species
diversity were natural and unrelated to the plant.
Numbers of Foraminifera per cc of dry sediment are plotted in Figure
25. The core from Station 3, off the desalination plant sea wall,
70
-------
TABLE IV ™RAL DISTRIBUTION OF FORAMINIFERA IN SEDIMENT CORES FROM STATION 3 AND BAY 2
SAFE HARBOR (A and ] = SEPTEMBER, 1970, K and 8 = SEPTEMBER, 1955)
SPECIES NAME
CORE 3
A B C D E *F G H
Ammonia becaamii parkinsoniana
Ammonia becoarrii tepida
Amphistegina lessonii
Arahaias angulatus
Artieulina lineata
Avticulina mexioana
Articulina mayori
Artioulina rmaronata
Artieulina sagra
Asterigerina aarinata
Bolivina inflata
Bolivina lanoeolata
Bolivina lowmani
Bolivina paula
Bolivina pulehella primitiva
Bolivina spathulata
Bolivina striatula
Bolivina subspinesoens
Bolivinita vhorriboidalis
Broeekina orbitolitoides
Buecella sp.
Bulimina marginata
Buliminella elegantissima
Cassidulina sp.
Cassidulina sub'globosa
Cibicides sp.
Clavulina triaarinata
Cornuspiroides foliaoeus
Cribroelphidiwn poeyanwn
Cyelogyra involvens
Cyelogyra planorbis
Discorbie mira
Elphidium advemon
Elphidiim exoavatwn
Elphidium fimbratulum
Elphidium gunteiei
Elphidium inoeTtum mexieaman
Elphidium sagmm
Fissuvina sp.
Fissurina pellueida
Florilus grabelovcpi
Fursenkoina complanata
Fwcsenkoina eompressa
Fux>serikoina mexioania
Fursenkoina pontoni
Globovotalia menardii
Eauerina sp.
Hemidisoella palabunda
Miliolinella oiraularis
Miliolinella fiehteliana
Miliolinella labiosa
Miliolinella suborbieulari
CORE
1
4567
* TIME OF CONSTRUCTION OF DESALINATION PLANT
71
-------
SPECIES NAME
CORE 3
A B C D
E *F G H I
CORE 2
K 1 2
3*2, 5678
Neooonorbina orbiaularis
Nonion sp.
Nonion depressulum matagordanum
Niibeaularia luaifuga
Osangularia oultur
Patellina oorrugata
Peneroplis oarinatus
Peneroplis pertusus
Peneroplis proteus
Planorbulina aoerval-is
Planovbulina mediterranensis
Planulina sp.
Pyrgo subsphaeriaa
Qui-nquelooulina agglutinans
Quinquelooulina biaarinata
Quinquelooulina bioostata
Quinquelooulina bidentata
Quinquelooulina bosaiana
Quinquelooulina funafuttiensis
Quinquelooulina laevigata
Quinquelooulina lamarokiana
Quinquelooulina poeyana
Quinquelooulina polygona
Quinquelooulina sabulosa
Quinquelooulina seminula
Quinquelooulina subpoeyana
Quinquelooulina tenagos
Quinquelooulina venusta
Quinquelooulina wiesneri
Reophax nana
Reussella atlantiaa
Rosalina flovidana
Rosalina floridensis
Rosalina rosea
Sigmavirgulina tortuosa
Sorites marginalis
Spirillina vivipara
Spirolooulina antillarum
Spirolooulina arenata
Textularia agglutinans
Textularia ear>landi
Tretomphalus atlantious
Trifarina bella
Triloaulina bassensis
Triloculina bermudesi
Triloculina oarinata
Triloculina fitterei meningoi
Trilooulina linneiana
Triloaulina planoiana
Triloaulina rotunda
Trilooulina trigonula
Troohammina inflata
Valvulina oviedoiar.a
72
-------
o
o
D_
CO
co
CC.
UJ
CO
3 ** 5 6
YEARS AGO (FROM SEPTEMBER, 1970)
48 in 1955
FIG. 24 SPECIES DIVERSITY IN FORAMINIFERA POPULATION FROM CORE SAMPLE AT STATION 3 (X) AND AT BAY 2 (0)
-------
3E
O
245 in 1955
o
QC
ct:
o
O
in
23^5
YEARS AGO (FROM SEPTEMBER, 1970)
FIG. 25 NUMBERS OF FORAMINIFERA PER CC OF DRY SEDIMENT FROM CORE SAMPLES AT STATION 3 (X) AND AT BAY 2 (0)
-------
showed two periods of declining populations; from October, 1964 to
June, 1966 and from November, 1967 until January, 1970. From January,
1970 to October, 1971 conditions steadily improved. Numbers of
Foraminifera increased from 218 per cc of dry sediment in September,
1970 to 621 in February, 1971; higher than present in all other strata
at Station 3. It is evident, therefore, that the high levels of
copper and nickel had little effect on the foraminiferan populations
except in the immediate vicinity of the discharge (see Section VIII
BIOLOGICAL PARAMETERS - Foraminifera below).
75
-------
SECTION VIII
BIOLOGICAL PARAMETERS
CONCENTRATIONS OF EFFLUENT AT BIOLOGICAL STATIONS
Figure 26* shows the amount of effluent found at each station from
August, 1970 to August, 1971. These averages exclude periods when
the desalination plant was shut down. The outer edge of the shaded
area represents percentage of effluent present at deeper stations
(within the effluent stratum) and the inner edge of the shaded area
represents percentage of effluent at the shallower stations. There
were no shallow collections at Stations 4 or 8. Station 4 was at
the point of effluent discharge and mixing was so active that measure-
ments were unreliable. Station 8 was the farthest station from the
effluent and the ledge was too shallow to permit two separate stations.
As pointed out in the section on copper levels, high concentrations
of effluent were present at shallow stations for brief periods follow-
ing resumption of desalination operations after maintenance periods.
Although some such instances were measured, the low frequency of
sampling coupled with the irregular times at which the plant resumed
operations prevented documenting the movement of the effluent through
the shallow stations. Therefore, although the average concentration
of effluent at the "A" series stations remained low, transient highs
were experienced which compared closely to the average conditions in
deeper water.
Figure 27 shows the mean percent of effluent and the 90 percent con-
fidence limits of the mean for all the deeper, series "B", stations
from August, 1970 to October, 1971. The series "B" stations showed
high effluent concentrations within the entrance canal of Safe Har-
bor and a marked reduction in concentrations both in the inner har-
bor (Station 1) and in the turning basin (Stations 7 and 9). The
average concentration of effluent was negligible at Station 8.
QUADRAT ANALYSES
On July 16th, 1970 one-meter square quadrats were set up adjacent to
the nineteen stations (Fig, 3). Organisms which were found in the
*Note that on Figure 26, 0 percent effluent is located two units from
the center of the circle on all radii. This is a result of the tech-
nique used for isolating the present effluent from ambient variations.
77
-------
FIG. 26 MONTHLY PERCENT EFFLUENT AT EACH STATION IN SAFE HARBOR FROM AUGUST, 1970
TO AUGUST, 1971. INNER EDGE REPRESENTS CONCENTRATIONS AT STATION A,
OUTER EDGE, STATION B.
Each
on
radius represents -}%
the circumference.
in the center,
Each radius is numbered as the hours on a watch and represents that month.
Values are read from the center to the circumference.
78
-------
o
cc
UJ
Q_
STATION
NUMBER
2500 2000
1000
1000
2000
3000 FEET FROM
DISCHARGE
FIG. 27 MEAN PERCENT EFFLUENT (SOLID LINE) WITH 90 PERCENT CONFIDENCE LIMITS OF THE MEAN
(BROKEN LINE) FOR ALL DEEPER STATIONS IN SAFE HARBOR FROM AUGUST, 1970 TO OCTOBER, 1971
-------
monthly quadrat and biomass samples are listed in Table V along
with their abundance values (average number of individuals per
square meter based on twelve monthly samples in a year's period).
Algae and hydroids and some of the small, burrowing, annelid
worms could not be satisfactorily counted and are listed as Common
(C), Present (P), or Absent (0). These organisms were not used in
calculating similarity or diversity indices for the stations.
Dominance diversity indices (Margalef 1957) were calculated for each
station (Fig. 28). They showed deeper stations were less diverse
than shallow stations and that diversity in Safe Harbor was lower
than in the turning basin or at the control station. At Station 5,
the deeper station was more diverse than the upper station, possibly
as a result of settlement by larval organisms entrained in the effluent.
The unusually high diversity of Stations 7A and 7B was due to a mixing
of faunas from Safe Harbor and the shallow water turtle grass flats.
The low diversity at Station 9B was caused by high siltation rates at
that station.
Similarity indices (Pearson et dl 1967) were calculated between all
stations in Safe Harbor to determine affinities in population struc-
ture (Table VI). Figure 29 shows the two largest similarity indices
for each station. (The figured squares represent the actual relative
geographic position of the quadrat stations in Safe Harbor). Station
IB, for example, was most closely related to Stations 2A and 2B.
Station 2B was most closely related to Stations IB and 3C. Stations
2A and 3A were closely related and apparently shared a fauna similar
to that associated with the effluent at Stations IB and 3C.
Based on similarity indices, the stations clustered into three main
groups with two intermediate stations. Stations IB, 2A, 2B, 3A, and
3C formed one group separated sharply at the point of effluent dis-
charge from a second group, Stations 4B, 5A, 5B, 6A, and 6B. The
third group of stations consisted of Stations 7A, 9A, 8A, 10A, and
10B. Station 1A showed its greatest affinities with Stations 5A and
6A. The fauna at Station 7B was most similar to the fauna at Stations
3C and 5B. Station 9B was loosely associated with Stations 5B and 4B.
Figure 30 shows the similarities between all of the shallow water (A)
stations in Safe Harbor. There were two abrupt changes in the fauna;
at the discharge to the desalination plant and between Stations 6A
and 7A. Stations 7 to 9 were in the turning basin and approach channel
while Stations 1 to 6 were in Safe Harbor proper (Fig. 3). At deep
stations (Fig. 31), the fauna remained similar from Station IB to 3C.
There was a marked drop in similarity between 3C and 5B at the point
of effluent discharge. The sharp decline in similarity shown for
the shallow stations between the harbor and turning basin was not as
pronounced in the deeper stations. The similarity in faunal popula-
tions between Stations 7B and 9B and the harbor stations may be attri-
buted to the movement of effluent into deeper portions of the turning
basin.
80
-------
TABLE V
List of invertebrates and algae found at all stations between July, 1970 and October, 1971. Number represents
abundance values of organisms (see test). Where these could not be calculated, C represents Common, P Present,
0 Absent.
Organ!sm
ASCIDIACEA
Asoidia nigra
Botrylloides nigrum
Spp. A
MOLLUSCA
Cantharus tinotus
Area imbricate.
Chama floridana
Littorina ziazac
Lima scabra
Ostrea frons
Ostrea equestris
Thais haemastroma
Strombus alatus
COELENTERATA
Eydrozoa
Plwnutaria sp.
Millepora aloioornis
Anthoza
Bartholomea annulata
Siderastrea radians
Solenastrea bournoni
Cladoaora arbusaula
Oeulina diffusa
Porites bannevi
Station
1
A
2.8
2.1
0
1.0
0
0
0
0
0.2
0
0
0
p
r
0
0
0
0
0
0
0
B
0
0
0
0
0
0
0
0
0
0
0
0
r
u
0
0
0
0
0
0
0
2
A
0
0.6
0
0
0
0
0
0
0
0
0
0
0
0
1.0
0
0
0
0
B
0
0
0
0
0
0
0
0
0
0
0
G
0
0
0
0
0
0
0
A
1.5
0
0
0.1
0
0
0
0
0.1
0
0
0
p
V
0
0
0
0
0
0
0
3
C
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
2.3
0
0.6
0.2
0
0
0
0
0.4
0.1
0
0
0
0
0
0
0
0
0
5
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
6
A
1.5
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
3.0
0
0.1
1.1
3.8
0.8
0
o.4
0.4
0
0
0.1
0
1.0
4.o
0
0
0
0
7 8
B A
0.5 0
0 0
0 2.0
0.7 0.1
0 3.0
0 4.0
0 0
0 0.2
0 0
0 0
0 0
0 0
PA
u
0 2.0
0 2.0
0 13.0
0 0
0 0
0 4.0
0 1 .0
A
5.6
0
4.0
1.0
12.0
0.4
0
0
0
0
0.1
0
0
0
1.0
0
0
0
0
9
B
0.6
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3.0
3.0
2.0
0
A
19.8
0
2.2
0
1.0
0
4.0
0.5
0
0
0
0
0
0.4
0
0
0
0
0'
JO
B
0.8
0
0
0
0
0
0.2
0
0
0
0
0
0
0
0
0
0.8
0
0
-------
Organ i sm
COELENTERATA cont.
Diahocoenia stokesii
Colpophyllia amaranthus
Muyioea elongata
Plexaurella nutans
Pseudoplexaura wagenaax>i
Pseudoplexaufa flagellosa
Pseudopterogovgia ameyiaana
PseudopteTogorgia rigida
Pseudopterogorgia aaerosa
Pterogorgia anoeps
Pterogorgia aitrina
ECHINODERMATA
Actinopyga agassizii
Astropecten dupliaatus
Astrophyton mupioatwn
ECTOPROCTA (BRYOZOANS)
~Bu.gu.1a sp.
CRUSTACEA
Menippe meveenaria
Panulirus argus
Periolimenes amerioanus
Alpheus floridanus
Pagurus sp,
Balanus amphitrite niveus
Stenopus hispidus
Squilla sp.
Station
A
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
0
0
0
0
0
0
0
0
0
2
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
0
0
0
0
0
0
0
0
0
3
c
0
0
0
0
0
0
0
0
0
0
0
0
0
0
4
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
0
0
0
0
0
0
0
0
0
5
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
0
0
0
0
0
0
0
0
0
6
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
0
0
0
0
0
0
0
0
0
7
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
8
A
1.0
2.0
6.0
5.0
8.0
2.0
6.0
4.0
3.0
6.0
3.0
0.1
0.2
0.1
A
0
0
0
0
0
0
0
0
0
0.2
0
0.1
0
0
9
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
0
0
0
0
0
0
0
0
0
10
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
92 84 66 15 85 21
37 8 25 11
0.6
0.3
0
0
0
0
210
0
0
0
0
0
0
0
O.It
0
0
0.5
0
0
0
0
85
0
0
0
0
0.2
0
0
6.0
0
0
0.2
0
8.0
0.2
0
190
0
0
0
0
9.0
0
0
10
0
0
0
0
0
0
0
65
0
0
0.1
0
0.1
0
2.0
17
0
0
0.1
0
0
0
0
49
0
0
0.1
0
4.0
0
0
0.5
0
0
0
0
6.0
0
0
0
0
0
0
0.2
0
0.4
0.4
0
0.2
0.2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.2
0.1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
-------
Organism
ALGAE
Cyanophyeeae
Oscillatoria sp.
Chlorophyaeae
Ealimeda discoidea
Caulerpa prolifera
Phaeophyceae
Dictyota dichotama
Ehodophyaeae
Gracilafia blodgettii
SERPULIDAE
S Ey oroides nowegica (elegans)
Hydroides pawa
Eydroides dirampha (lunulifera)
Pomatostegus stellatus (?)
Hydroides sp.
Serpula sp. (undesaribed)
Spirorbis sp.
CIRRATULIDAE
Cirriformia filigeva
fharyx marioni
EUNICIDAE
Eunice floridana
Eunice oaviboea
Eunice antennata (?)
Eunice sp. A
Eunice sp. B
Lysidice oollaris
Nematonereis sp.
Station
A
C
0
0
0
p
36
0
445
0
0
0
0
P
C
0
0
0
0
0
0
0
1
B
C
0
0
0
0
46
0
2467
0
0
0
0
0
P
0
0
0
0
0
0
0
A
C
0
0
0
P
294
0
2393
0
0
0
0
68
C
22
0
0
0
0
0
0
2
B
C
0
0
0
0
60
0
3263
0
0
0
0
p
p
0
0
0
0
0
0
0
A
C
0
0
0
p
350
0
1950
0
0
0
0
211
740
11
0
0
9
0
0
0
3
C
p
0
0
0
p
150
0
2062
0
0
0
0
81
50
11
0
0
0
0
0
0
4
B
0
0
0
0
0
0
0
205
0
0
0
0
0
0
0
0
0
0
0
0
0
A
p
0
0
0
p
49
0
440
0
0
0
0
p
p
20
0
0
0
0
0
0
5
B
P
0
0
0
0
20
0
170
0
0
0
0
0
0
0
0
0
0
0
0
0
A
p
0
0
0
p
8
0
220
0
0
0
0
P
P
P
0
0
0
0
0
0
6
B
0
0
0
0
0
0
0
426
0
0
0
0
0
p
0
0
0
0
0
0
0
A
p
C
0
p
p
0
7
0
10
1
10
0
0
63
39
10
10
0
30
40
1
7
B
P
0
0
0
0
20
0
185
0
24
73
0
2
560
12
0
0
0
0
10
0
8
A
0
C
0
P
0
0
0
0
0
0
0
0.2
0
0
0
0
0
0
0
0
0
A
0
C
P
P
0
0
0
0
0
0
12
0
0
0
0
10
0
0
0
0
0
9
B
p
r
P
P
0
0
0
0
0
129
0
0
0
0
0
0
0
0
0
0
0
0
0
A
p
I
p
p
C
0
0
2
10
2
0
0
0
0
25
13
0
0
0
0
0
0
0
10
B
p
r
P
p
P
0
0
4
53
6
0
0
0
10
0
0
0
0
0
0
0
0
0
-------
Organ! sm
SYLLIDAE
SylZinae sp. A
SylZinae sp. B
LUMBRINERIEDAE
SABELLIDAE
Spp. A
Spp. B
Branch-Comma nigromaaulata
PotamiZla reniformis
Hypsicomus eZegans (?)
Jasmineira sp.
DORVEILLEIDAE
Dorvilla sp.
TEREBELLIDAE
Terebellobranehia riaki
Pista cristata
HESIONIDAE
NEREIDAE
SPIONIDAE
PHYLLODOCIDAE
LYSARETIDAE
Oenone fuZgida
CAP 1 TELL 1 DAE
Station
A
0
0
0
0
0
850
0
0
0
0
0
0
0
0
0
0
0
0
1
B
0
0
0
0
0
640
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
445
0
0
0
0
0
0
0
0
0
0
0
0
2
B
0
0
0
0
0
185
0
0
0
0
0
0
0
0
0
0
0
0
A
1.2
1.2
5
0
0
453
0
0
0
0
0
0
0
0
1
0
0
2
3
C
13
0
0
0
0
20
0
0
0
0
0
0
0
0
0
0
0
0
4
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
250
0
0
0
0
0
0
0
0
0
0
0
0
5
B
0
0
0
0
0
113
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
360
0
0
0
0
0
0
0
0
0
0
0
0
6
B
0
0
0
0
0
70
0
0
0
0
0
0
0
0
0
0
0
0
A
20
0
60
11
15
10
0
15
0
10
12
0
4
1
1
2
1
0
7
B
30
0
11
0
0
21
20
0
10
10
0
0
0
0
0
0
1
0
8
A
0
0
0
0
0
0.1
0
0.5
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
0
0
11
0
0
0
0
0
0
0
0
0
0
9
B
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
A
0
0
0
0
0
0
0
2
0
0
5
3
0
0
0
0
0
0
10
B
0
0
0
0
0
4
0
0.2
0
0
1
17
0
0
0
0
0
0
-------
STATION
8 NUMBER
X
UJ
>-
co
10A
IOB
2500 2000
1000
1000
2000
3000 FEET FROM
DISCHARGE
FIG.28 DOMINANCE DIVERSITY INDICES FOR ALL SAFE HARBOR STATIONS BASED ON COLLECTIONS
ACCUMULATED FROM JULY, 1970 TO OCTOBER, 1971. X = B STATIONS, 0 = A STATIONS.
-------
TABLE VI
FAUNAL SIMILARITY INDICES BETWEEN SAFE HARBOR STATIONS
STATIONS 1A IB 2A 2B 3A 3C 4 5A 56 6A 6B ?A 7B 8 9A 9B 10A
!A
IB 0.494
2A 0.430 0.892
2B 0.266 0.802 0.766
3A 0.428 0.575 0.790 0.587
3C 0.262 0.759 0.790 0.796 0.714
4 0.140 0.127 0.148 0.140 0.126 0.159
^
5A 0.637 0.381 0.388 0.320 0.333 0.340 0.408
5B 0.360 0.173 0.193 0.163 0.164 0.164 0.695 0.557
6A 0.596 0.335 0.323 0.217 0.279 0.192 0.592 0.813 0.764
6B 0.471 0.270 0.261 0.251 0.226 0.315 0.524 0.762 0.568 0.651
7A 0.014 0.006 0.017 0.005 0.037 0.059 0 0.055 0.026 0.028 0.022
7B 0.173 0.107 0.110 0.100 0.322 0.176 0.293 0.264 0.313 0.304 0.275 0.215
8 0.0001 0 0.0005 0 0.0001 0.0001 0 0.001 0.0001 0.0001 0.0001 0.013 0.0003
9A 0.004 0 0.001 0 0.001 0 0 0.007 0 0.006 0 0.177 0.025 0.028
9B 0.146 0.076 0.037 0.070 0.062 0.101 0.633 0.271 0.518 0.461 0.397 0.002 0.229 0.003 0.006
10A 0.008 0.002 0.01? 0.002 0.021 0.033 0.011 0.015 0.018 0.021 0.007 0.102 0.036 0.006 0.147 0.023
10B 0.017 0.008 0.008 0.008 0.008 0.011 0.033 0.032 0.061 0.057 0.033 0.053 0.027 0.003 0.013 0.051 0.205
-------
2500 2000
STATION
NUMBER
1000
2000
3000 FEET FROM
DISCHARGE
FIG. 29 TWO LARGEST SIMILARITY INDICES FOR EACH STATION IN SAFE HARBOR, INDICATING AFFINITIES IN
POPULATION STRUCTURES, FROM JULY, 1970 TO OCTOBER, 1971.
-------
00
00
1 0 ] '
0.8 -
X
LLJ
| 0.6 -
>-
01
3 0.4 -
z
(/>
0.2 -
\
c
s
/
S
/
/
/
n ' <
2500 2000
! 3 <
1
1 0
^ • /*\ u
' \
\
\
.
\
n ^
1
5 6
1 1
0— r-O
M
/ \
/ \
A
\ c
£\-x /•
1
1000 0 1000
STATION
/ 9 8 NUMBER
1
N _ S\
>"<
) 0 ^^- Q
,P °
2000 3000 FEET FROM
DISCHARGE
•fc TMRMIMH RfillM
FIG.30 SIMILARITIES IN POPULATION STRUCTURE BETWEEN SHALLOW STATIONS IN SAFE HARBOR
FROM JULY, 1970 TO OCTOBER, 1971.
-------
, 0 1 2 34
0.8 -
X
LU
| 0.6 -
>-
h-
OL
3 o.4
z:
CO
0.2
0
2J
1 1 1
ON f"\ II . Ill fi
\
\
\
\
\
\
\
\
V
V
\
\
\
\
\
0 5
1 1 1
00 2000 1000 f
HARBOR rANAI ^
STATION
56 79 8 NUMBER
1 1 II
7\
/ s
/ \
/ s
i n \_ — — fi
\_ Q
II II
) 1000 2000 3000 FEET FROM
I DISCHARGE
' ^ TMOMIMr DflCIM
FIG. 31 SIMILARITIES IN POPULATION STRUCTURE BETWEEN DEEP STATIONS IN SAFE HARBOR
FROM JULY, 1970 TO OCTOBER, 1971.
-------
The quadrats provided a means of recording chronological changes
in the macroinvertebrate fauna. Two of the quadrats were at
locations set up in December, 1968. Clarke's (1970) Station 3,
directly in the path of the effluent plume, became Station 4.
From 1968 to 1971 only a sparce cover of serpulids and barnacles
were common in this quadrat.
Clarke's (1970) Station 2A became Station 3A. There were marked
changes in this quadrat from 1968 to 1971 in the number of speci-
mens of Asaidia nigra. In December, 1968, there were three per square
meter. This value rose to fifteen per square meter by February, 1969
and was ten per square meter in May, 1969. In July, 1970, there were
six per square meter and by September, 1970, A. nigra had vanished
from the quadrat as well as from the adjacent rock wall. By the end
of October, 1970, A. nigra was gone from all of the entrance canal
and inner harbor stations except 1A where they persisted until April,
1971. In September, 1971, ten specimens of A. nigra were present at
Station 3A and in October there were seven specimens. The increase
in numbers of A. nigra followed the pronounced drop in ambient dis-
solved copper and in copper content in the effluent (figs. 10 and 11).
The green algae, Cladophovopsis membranacea, and the red-green algal
turf which was abundant in 1968 and during the summer months of 1970,
was missing from 3A from October, 1970 to July, 1971. Cheilostomatid
bryozoans (Bugula sp. ) which were common in 1968 and the early summer
months of 1970 were absent from March, 1971 until September, 1971.
In August, 1970 Branchiomma nigromaeulata, a sabellid worm, became
very abundant at Station 3A. In November and December, 1970 these
worms died out in a mass mortality from unknown causes. Populations
of B. nigromaculata did not die in embayments adjacent to Safe Har-
bor, nor is .the animal known to be seasonal in other Florida areas
(Taylor, personal communication)- In July, 1971 B. nigromaoulata
populations became established again at 3A. In October, 1971, however,
relatively few remained.
From December, 1970 until July, 1971 the fauna at Station 3A consisted
primarily of serpulid worms (mostly Hydroides dirampha), a few barna-
cles (Balanus amphitrite), and two polychaete worms (Cirrifownia
filigera and Tharyx marioni). These organisms maintained good popula-
tions at 3A from July, 1970 until October, 1971.
Station 1A was near Clarke's (1970) Station 1 in the inner harbor.
A. nigra remained at about the same level of abundance at the inner
harbor station from December, 1968 until February, 1971. There were
three individuals per square meter in December, 1968; six in January,
1969; five in June, 1969; three in July, 1970; five in September, 1970;
and seven in December, 1970. By April, however, the number decreased
to zero, where it remained until one specimen appeared in October, 1971.
Bryozoan colonies remained in good condition at 1A through the study
period.
90
-------
All stations in the effluent (i.e. the "B" series of stations) with
the exception of 9B and the control station 10B, were similar. The
quadrats were on rock outcroppings covered with a thick layer of
serpulids (H. dirampha and H. norvegica). A few bryozoans (Bugula sp.)
occurred at most stations in the summer of 1970 (4B had none), and
occasionally sabellids settled on the rocks. Siltation was heavy in
these quadrats and Station 6B, directly across from the discharge,
completely silted over in December, 1970 killing everything in the
quadrat.
There was a marked difference between the faunas in the "A" and "B"
series quadrats throughout the Safe Harbor area during 1970. In
1971, however, deteriorating conditions at Stations 2A, 3A, 5A, and
6A caused these to resemble the lower stations (Fig. 29, Table VI).
Station 7B (in the turning basin) showed many faunistic similarities
with B stations inside the harbor, including a good serpulid fauna,
a few bryozoans and ascidians, and little algae. The abundance of
dead Chama and Aora shells attached to the wall also resembled the
lower portions of the wall in the harbor. Station 7A, only about ten
feet above 7B, was markedly different from 7B and the other stations
in the harbor (Fig. 20). There were few serpulids or sabellids,
good algal growth (predominantly Ealimeda sp.)» an occasional lobster
(Panulirus argus), colonial tunicates, three genera of lamellibranch.es
(Lima scdbra, Chama floridanas and Aora imbricata), coral colonies
(Siderastrea radians'), shrimp (Stenopus hispidus), an anemone (Bar-
tholomea annulata) , and from two to five specimens of A. nigra (Table
V). In December, 1970 the Acra imbricata died and the Chama flori-
dana were not present in February, 1971. The Ealimeda was in poor
condition in February, 1971 and dead by April, 1971.
Station 8, in the approach channel to the turning basin, bore almost
no similarity with Safe Harbor stations (Fig. 29, Table VI). The
Station 8 quadrat had numerous gorgonian colonies, many specimens
of Aora imbrioata and Chama floridana and coral colonies (Table V).
Absence of A. nigra., serpulids, and other 'harbor' organisms indicated
this area was not frequently exposed to effluent water.
The control station, about one mile from Safe Harbor stations (Fig. 3)
had a prolific fauna and flora similar to that recorded from Safe
Harbor in the Phase I investigation. The two stations (10A and 10B)
were placed on a vertical rock face, thirty feet (9m) high. Like the
Safe Harbor counterpart, siltation was rapid and water circulation
slight. The thirty foot (9m) deep basin which adjoined undeveloped
U.S. Naval property (and received no effluents) was separated from
Boca Chica Channel by a sixteen foot (5m) deep ridge. It was, there-
fore, physically quite similar to the Safe Harbor area. Station 10A
had an average of 19.8 Asoidia nigra per square meter from November,
1970 until October, 1971. Three species of green algae made up the
majority of the algal population which covered about twenty Percent
of the quadrat. There were relatively few serpulids or sabellids,
91
-------
several large terebellids, Lima scabra. Area irribriaata* two
anemones, and several specimens of Cirri formia sp. (Table V).
Station 10B, in thirty feet (9m), had an average of 0.8 Aseidia
nigra per square meter. Four species of green algae including
Udotea sp. and some five species of sabellids and serpulids were
also present in the study quadrat.
FORAMINIFERA
Foraminifera were examined quarterly from sand or mud near each
quadrat. The number of live Foraminifera per cc of wet sediment
are plotted in Figures 32 and 33. Analysis of these figures leads
to the following conclusions:
1. Effluent from the desalination plant reduced numbers
of Foraminifera in the immediate vicinity of the
outfall but increased the number of Foraminifera
elsewhere in the harbor when compared to Control
Station 10.
2. Shallow water stations were more densely populated
with Foraminifera than deep water stations in Safe
Harbor, except in April, 1971 when deep and shallow
foraminiferan population densities were almost the
same and in October, 1971 when there were more
Foraminifera at deep water stations which was nor-
mally the case at Control Station 10.
3. Numbers of living Foraminifera increased from the
inner harbor seaward. Generally, they were highest
at stations in the turning basin.
4. Shallow water Safe Harbor stations averaged higher
foraminiferan population densities than the Control
Station. Deep water Safe Harbor stations averaged
lower foraminiferan population densities then the
Control Station in October, 1970 were almost the
same in January and July, 1971, and considerably
higher than the control area in April and October, 1971.
TRANSECTS
Two transects were monitored every month along the eastern edge
of the entrance canal. One transect extended along the desalination
plant sea wall 434.7 feet (132.5 meters) and covered a swath from the
intertidal zone down to the soft sediment at the bottom of the channel
92
-------
1000k
OJ
1000 K
800
1000
JAN 71
CONTROL
OCT 70
APR
JULY
1547
OCT
FIG. 32 LIVE FORAMINIFERA PER CC OF WET SEDIMENT FOUND AT ALL SHALLOW
WATER STATIONS FROM OCTOBER, 1970 TO OCTOBER, 1971.
-------
VO
1000
JAN '71
2000
CONTROL
OCT '70
FIG. 33 LIVE FORAMINIFERA PER CC OF WET SEDIMENT FOUND AT ALL DEEP
WATER STATIONS FROM OCTOBER, 1970 TO OCTOBER, 1971.
-------
in about twenty feet (6.1m) of water. The second transect extended
along the 250 foot (76.2 meter) sea wall where the new City Electric
plant is being constructed. These two areas correspond closely to
transect locations for the earlier 1968-69 study (Clarke et al 1970)
Distributions of black tunicates (Aseidia nigrd), stone crabs
(Memppe mercenaria), lobsters (Panulirus argus), algae, bryozoans
serpulids, sabellids, and barnacles were plotted underwater on
plastic sheets imprinted with scale drawings of the transect areas.
Figure 34 shows the monthly abundance (in numbers of individuals
per 100 linear feet of sea wall) of A. nigra* M. mercenaria, and
P. argus along the two transects. The abundance indices in Table
VII, show that the numbers of all three organisms declined in both
areas through June, 1971. In September, 1971, A. nigra achieved population
levels comparable to those obtained for the 1968 study and the numbers
of P. argus increased to 1970 levels along the City Electric plant
sea wall. Numbers of M. meroenaria decreased well below 1968 and
1970 levels.
Comparisons between the two transect areas in Figure 34 show A.
nigra was in lower numbers near the desalination plant (until August,
1971); M. meroenaria had similar numbers of individuals in both areas
and P. argus tended to congregate in the desalination plant area during
cooler months. Fluctuations in the numbers of P, argus were probably
due to seasonal migrations in and out of shallow water areas.
The most notable changes during the monthly transects were a mass
mortality of Branahiomma nigvomaaulata from October to November, 1970,
and overall decline of algal turf and bryozoan colonies from October,
1970 to April, 1971, and the settlement and subsequent disappearance
of Asoidi-a nigra in July, 1970 and a successful resettlement of A.
nigra, algae, and bryozoans in August, 1971.
Observations were made of the fish populations inhabiting the transect
and control areas. Since fish moved freely in and out of the Safe
Harbor area and water visibility often limited observations under
water, there was no satisfactory way of quantitatively assessing
changes in the total fish population. Observations of fish occur-
rences made during the preliminary survey (Clarke et al 1970) remained
essentially unchanged for the study period from 1970 to 1971, and few
additions were made to the species list presented in the earlier study.
Observations during the past year confirmed the earlier observations
that fish were attracted to the vicinity of the effluent and, in fact,
numerous species were observed repeatedly swimming into the core of
the effluent discharge. The tarpon (Megalops atlantiea), mahogany
snapper (LutJanus mahogoni), grey snapper (LutJanus griseus), and
others were consistantly seen in the hottest portion of the effluent.
Indeed, the desalination plant sea wall had the largest number of fish
and the greatest number of species seen anywhere in the harbor, turn-
ing basin, or control stations. Fish counts were occasxonally made
when water clarity permitted but these were of questionable accuracy
95
-------
FIG. 34 NUMBER OF INDIVIDUALS PER 100 FEET OF CANAL WALL IN
SAFE HARBOR, STOCK ISLAND, FLORIDA KEYS, JULY, 1970
TO OCTOBER 1971. UNSHADED AREA REPRESENTS 1970,
SHADED AREA REPRESENTS 1971
Asoidia nigra 0-20
Menippe mereenar-La 0-20
Panulirus argus 0-5
CITY ELECTRIC
DESALINATION PLANT
96
-------
TABLE VII
TRANSECT COMPARISONS 1969, 1970. 1971
Abundance of organisms (number per linear 100 feet of sea wall)
June, 1969 Desalination plant
sea wal 1
City Electric sea
wall
July, 1970 Desalination plant
sea wal 1
City Electric sea
wal 1
June, 1971 Desalination plant
sea wal 1
City Electric sea
wall
Sept. 1971 Desalination plant
sea wal 1
City Electric sea
wall
Asaidia
100
?
2.1
25.0
0
0
118.4
4.4
Panulirus
3-0
16.7
0.5
0.8
0.23
0.40
0
0.8
Menippe
25. 0
5.6
14.3
25.0
2.53
0.80
6.7
1.6
97
-------
since the larger fish could easily move ahead of the divers and
avoid being counted or, in some cases, be counted more than once.
Relative numbers of fish per unit distance, however, were obtained.
In January, 1971, for example, 120 fish were counted per 100 feet
(33m) of sea wall at the City Electric sea wall.
Fish showed definite avoidance reactions to turbid effusions from
the desalination plant which followed the onset of operations after
the plant had been shut down for maintenance. Large schools of
snapper, mullet, and anchovies, as well as other species of fish,
were observed swimming away from the turbid effusions or hovering
in the adjacent clearer waters. Schools of mullet and anchovies,
trapped by the turbid effusions in the inner canal entrance, were
observed swimming in a distressed manner rapidly towards the harbor
mouth. It could not be ascertained if fish were avoiding water
turbidity or if they were responding to some other chemical contam-
inant. Sprague (1964) has made some observations along those lines,
discussing the reactions of salmonid fishes to copper and zinc solu-
tions at levels of 20 ppb in freshwater.
Many species of fish become inactive at night (Starck and Davis 1967).
Night dives in the Safe Harbor canal revealed specimens of snook
(Centpopomus undecimaUs) inactive on the floor of the canal and a
variety of other fishes quietly resting along the rocky walls of the
canal. These fish, presumably, would not flee high levels of contami-
nants should they be released at night. Many smaller species retreated
into holes and crevices in the canal wall when alarmed during the day
and were also unlikely to escape the contaminants in the effusions when
they engulfed the area.
While it was true that fish congregated in the vicinity of the effluent
when the desalination plant was operating normally, it does not necess-
airly follow that this was beneficial to them. Attractive parameters
of the effluent such as heat and entrained plankton may have lured fish
into the area while toxic parameters may have physiologicall damaged
them. Several fish were observed with epidermal lesions and histolog-
ical examination of livers from Safe Harbor fish, discussed below,
indicate that, in fact, copper toxicity was deleterious to some of the
smaller fishes inhabiting the harbor.
In addition to the transects in Safe Harbor Canal, a series of transects
were made both east and west of the turning basin, to determine effects
of effluent moving over the western edge of the turning basin and onto
the turtle grass flats. Observations by divers indicated that the
echinoid population in the path of the effluent decreased markedly during
1970. The numbers per square meter of Lytechinus variegatus and Tvip-
neustes ventriaosus found in transects east and west of the turning
basin are shown in Figure 35.
98
-------
0.47 ECHINOIDS PER M2
0.40
0.78
0.53
/ I
0 ECHINOIDS PER M2
0 (0.04 DIADEMA PER M2)
FIG. 35 NUMBERS OF LYTECHINUS VARIEGATUS AND TRIPNEUSTES VENTRICOSUS PER
SQUARE METER IN TURTLE GRASS FLATS EAST AND WEST OF THE SAFE
HARBOR TURNING BASIN
99
-------
With the exception of five Diadema ant-illarum at the most distant
points of the western transects, no live echinoids were seen in
the flats west of the turning basin. Dead Lyteohinus variegatus
and Tripneustes Ventricosus tests and fragments were found in the
area indicating the recent presence of living specimens there.
During the 1968 and 1969 surveys, both Lytechinus variegatus and
Tripneustes venticioosus occurred in the same area with densities
closely approximating the recent population to the east of the turn-
ing basin (Clarke, unpublished data). Laboratory and in situ bio-
assays showed a high sensitivity of echinoids to the copper con-
tained in the effluent. The high copper levels in sediments west
of the turning basin implicate the flow of effluent over the flats
as the cause of the echinoid mortality.
In November, 1971, an aerial photo transect was made over the turn-
ing basin to determine if there had been any changes in the pattern
of turtle grassj Thalassia testudinwrij along its borders since a
similar photo transect was made in 1968 (Fig. 36). There were no
detectable changes. In fact, the stability of the turtle grass was
remarkable. Note, for example, the persistent shape and size of
sand patches just off the two prominences which form the entrance to
the canal (Fig. 36). The width of the barren area between the edge
of the turning basin and the Thalassia beds did not change appreciably
although in the 1971 survey it was covered with more algal, growth, and
was thus darker in color.
PLANKTON TOWS
Plankton tows were taken along the desalination plant sea wall and
along the eastern edge of the turning basin wall at Station 9. To
determine effects of effluent on plankton populations, tows at
Station 9 were used as references to compare with tows in front of
the desalination plant. Shallow tows and deep tows were compared
with each other and the number of plankters at the desalination plant
expressed as percentages of comparable tows at Station 9. In October,
1970, the deep tow at the desalination plant had 33.8 percent the
number of diatom cells found in the deep tow at Station 9. The com-
parable percentage for the shallow tows was 45.5 percent. Theoretically,
the two tows at the desalination plant should have the same percentage
differences from the control station tows. Effluent caused a greater
reduction of the expected percentage in deep water (i.e. 33.8 percent
rather than 45.5 percent). In October, therefore, the deep tow had
only 74.3 percent the number of phytoplankters expected.
When the desalination plant was shut down, deep water was more pro-
ductive than shallow water, averaging 132 percent more than
the theoretical population. When the plant was operating the deep,
effluent-laden, water averaged only 50.57 percent of the expected
phytoplankton population.
100
-------
CO
CT>
00
co
Fig. 36 AERIAL SURVEYS OF TURTLE GRASS BEDS ADJOINING
THE SAFE HARBOR TURNING BASIN (1968-1971).
101
-------
Zooplankton data were limited. Some samples had to be acidified
to remove excessive amounts of silt. Acid treatment, of course,
made zooplankton counts unreliable. The data obtained showed a
decrease in zooplankton populations in effluent-laden water. In
October, the deep tow at the desalination plant yielded only
39-87 percent of its potential population compared to the shallow
tow. In December, the zooplankton population in the deep tow was
only 14.28 percent of its theoretical level. In April, the desali-
nation plant was not operating and the zooplankton in the deep tow
reached 167 percent of its theoretical population.
SETTLEMENT PANELS
Settlement panels provided data on the distribution and abundance
of a variety of sessile filter feeders in Safe Harbor. For the first
four months different materials were used for the panels to determine
which surface provided the most suitable substrate for both settlement
and analysis. By November, plywood panels were selected as the best
material and analytical procedures were stabilized (see Section IV
Methods and Procedures).
Monthly collections were carried out for twelve months, from November,
1970 to October, 1971. During the yearly cycle, three organisms
dominated the panels; serpulid worms (Hydroides norveg-ica), sabellid
worms (Branahiomma nigromaaulata), and barnacles (Balanus amphitvite
niveus)• Other organisms which settled on the panels included hydroids,
filamentous red and green algae, tunicates and bryozoans. These latter
organisms occurred so infrequently at the stations that they were of
little quantitative value. They became more abundant beginning in
July, 1971 and reached a peak for the year in August and October. This
peak was not present during the previous year and it is probable that
the drop in copper discharge levels which began in June contributed to
the improvement of living conditions for these organisms.
From November, 1970 to May, 1971, the settlement panels yielded an
almost unispecific settlement of serpulid worms; a condition reflected
in transect and quadrat analyses of the benthic fauna. Figures 37
through 40 show the distribution and abundance of the serpulid worms
during the twelve month study period. They were most abundant in
November, 1970. Their numbers gradually decreased until June, 1971
when there was a sudden change in the pattern of distribution of the
worms and a marked decrease in their total abundance throughout the
harbor. While the serpulid worms were clearly more tolerant of the
effluent than other sessile organisms, the marked reduction in their
numbers at Station 3C (Figs. 39 and 40) compared with adjacent stations
clearly shows the deleterious impact of the effluent. This adverse
effect is also brought out in Figure 41 which shows the mean number
of serpulid worms at each station during the entire year. More serpulids
102
-------
20
NORTH
1000 FT
DISCHARGED
APR
MAR
FEB
JAN
DEC
NOV
1000 FT
FIG.37 NUMBERS OF SERPULID WORMS ON 30-DAY SETTLEMENT PANELS AT SHALLOW
WATER SAFE HARBOR STATIONS NOVEMBER, 1970 TO APRIL, 1971.
-------
o
-IN
NORTH
\
1000 FT
DISCHARGE
MAY
FIG.38 NUMBERS OF SERPULID WORMS ON 30-DAY SETTLEMENT PANELS AT SHALLOW
WATER SAFE HARBOR STATIONS MAY TO OCTOBER, 1971.
-------
o
Ln
30
NORTH
1000 FT
DISCHARGED
FEB
JAN
NOV
MAR
1000 FT
DEC
FIG.39 NUMBERS OF SERPULID WORMS ON 30-DAY SETTLEMENT PANELS AT DEEP
WATER SAFE HARBOR STATIONS NOVEMBER, 1970 TO APRIL, 1971
APR
-------
10
1000 FT
MAY
FIG.40 NUMBERS OF SERPULID WORMS ON 30-DAY SETTLEMENT PANELS AT DEEP
WATER SAFE HARBOR STATIONS MAY TO OCTOBER, 1971.
-------
1000
STATION
NUMBER
2000
1000
1000
2000
3000
FEET FROM
DISCHARGE
FIG. 41 MEAN NUMBER OF SERPULID WORMS SETTLING PER 50cm2 PER MONTH AT BIOLOGICAL STATIONS IN
SAFE HARBOR (NOVEMBER, 1970 TO OCTOBER, 1971).
-------
settled at deep stations than shallow stations except for Station 3C.
Figure 26 shows that the amount of effluent reaches a peak at Station
3C, averaging about three percent by volume throughout the year.
Figures 42 and 43 show the number of serpulid worms settling per
thirty day period compared with exposure to effluent. Since the
seasonal availability of larvae, water currents, and larval behavior
all interacted with water quality to determine numbers of individuals
settling at any particular station, a 'serpulid index' was derived
by comparing settlement at the "B" stations with the "A" stations directly
above them. At any given time, both the "A" station and "B" station,
separated by about 16 feet (4.8 meters), should have had similar
exposure to larvae. By comparing the two stations for each month,
differences due to availability of larvae were eliminated and the
resulting differences in the abundance of larvae at the two stations
reflected the influence of the effluent at the deeper station.
A-B
Use of the formula I = -—- (where J is the serpulid index, A the
ATD
number of serpulid worms settling during a thirty day period on 50cm2
at the "A" station, and "B" the number of serpulid worms settling in the
same time period on 50cm2 at the "B" station) permitted direct compari-
son of the relative effect of the effluent throughout the year. If
all of the serpulids settled at the deeper stations, the index would
be -1 and if they all settled at the shallow station the index would
be +1.
For the first six months of observation more serpulid worms settled
on the shallower panels as the amount of exposure to effluent increased
at the deeper panels (Fig. 42). In May, exposure to effluent was rela-
tively constant throughout the harbor and the relative amount of settle-
ment was also constant (Fig. 43). July and August were notable excep-
tions to the pattern shown in previous months. Relative numbers of
serpulid worms settling in the different stations varied greatly, but
were not related to the amount of effluent present (Fig. 43). During
these two months the amount of copper discharged by the desalination
plant was at a minimum (see section on copper and nickel above).
Settlement of the barnacle (Balanus amph-itvite niveus) was seasonal
with almost no settlement during the colder months of December through
March. The adult barnacles on boats entering and mooring in the harbor
contributed numerically to the local stock of adults in the inner har-
bor and so, the inner harbor was probably the major source of barnacle
larvae. Tide and wind currents dispersed the larvae seaward, past the
desalination plant. Most larval settlement was at shallow stations
with Stations 2A and 3A receiving the highest number (Fig. 44). Few
barnacles were able to settle on the seaward side of the effluent
with the notable exception of Station 5B. At Stations 7A and 7B in
the turning basin, only six specimens settled on the test panels from
November, 1970 until July, 1971. This indicated that the desalination
plant discharge formed a barrier to the movement of barnacle larvae
out of the harbor.
108
-------
100
x
LU
O
O
O-
X
LU
20-
+.4 +.6 +.8 +1
SERPULID INDEX
FIG. 42 MONTHLY INDICES (NOVEMBER, 1970 THROUGH APRIL, 1971) OF SERPULID WORMS
SETTLING ON 50cm2 WOODEN PANELS AT BIOLOGICAL STATIONS IN SAFE HARBOR
COMPARED TO EFFLUENT EXPOSURE. SEE TEXT FOR EXPLANATION.
-------
100
x
LU
Q
CCL
•^
CO
o
D_
X
80 -
60 -
40
20 -
-1
SERPULIO INDEX
FIG. 43 MONTHLY INDICES (MAY, 1971 THROUGH OCTOBER, 1971) OF SERPULID WORMS
SETTLING ON 50cm2 WOODEN PANELS AT BIOLOGICAL STATIONS IN SAFE HARBOR
COMPARED TO EFFLUENT EXPOSURE. SEE TEXT FOR EXPLANATION.
-------
20
3 4
STATION
NUMBER
o
C£.
LU
Q_
<
a:
CO
10
0-
2500
J 1
A STATIONS
B STATIONSI
2000
1000
1000
2000
3000
FEET FROM
DISCHARGE
FIG. 44 MEAN NUMBER OF BARNACLES SETTLING PER 50 cm2 PER MONTH AT BIOLOGICAL STATIONS IN
SAFE HARBOR (NOVEMBER, 1970 TO OCTOBER, 1971).
-------
Doochin and Smith (1951) showed that B. conphitrite settlement and
growth were influenced by the velocity of water currents and Weiss
(1948), Bertholf (1945), and Glaser and Anslow (1949) showed that
shock from increased temperature, salinity and copper or reduced
pH induced metamorphosis in barnacles and other invertebrates. All
of these factors were characteristic of the discharge. Probably,
barnacle larvae entrained in the effluent were induced to settle
and metamorphose because of the combination of sudden increase in
water velocity, temperature, salinity and copper along with the
decrease in pH. The high rate of siltation at most of the deeper
stations near the discharge prevented successful settlement of
barnacle larvae. Many of the test panels were heavily covered with
silt at Station 6B during the course of the study and the quadrat
at that station was completely buried with silt. Station 5B, there-
fore, was the station at which most of the successful settlement of
the entrained barnacle larvae occurred, explaining the peak in num-
bers shown in Figure 44.
Sabellid worms, Branchiomma n-igramaculata, were the third most com-
mon invertebrate settling on the test panels. They were abundant
during August through October, 1970. In October and November, 1970
there was a mass mortality of sabellid worms in Safe Harbor. The
worms, which live in parchment-like tubes and feed on plankton,
dropped out of their protective tubes and died, beginning at the
desalination plant sea wall in October, and by December, reaching
harbor stations. This mortality was not repeated in October, 1971
although the total number of sabellid worms settling on the test
panels declined. Figure 45 shows the mean number of sabellid worms
settling at the biological stations in Safe Harbor from November,
1970 to October, 1971. A decline associated with proximity to the
desalination plant is evident.
All three of the common organisms on the test panels were adversely
affected by high concentrations of effluent, but were much more
abundant in Safe Harbor than at the control stations or in adjoining
harbors. At the control stations, for example, a total of two B.
amphitrite, twenty-two B. nigromaaulata, and thirty H. norvegiea
settled on test panels during the twelve month period.
DIATOMETERS
Glass microscope slides were placed in PVC pipe racks at selected
stations. Every two weeks, these were exchanged for a new set of
slides and the exposed set was examined for protozoans and diatoms.
Numbers of species and numbers of individuals per month were plotted
(Figs. 46 and 47) and the values compared. Stations 3A, 7A, and 10A
were shallow stations at 8 feet (24 meters), whereas Stations 3C, 7B,
and 10B were deep stations at 28 feet (8.5 meters). Stations 10A and
112
-------
100
o
-, 40
LU
CO
STATION
NUMBER
0
2500 2000
1000
1000
2000
3000 FEET FROM
DISCHARGE
FIG. 45 MEAN NUMBER OF SABELLID WOEMS SETTLING PER 50cm2 PER MONTH AT BIOLOGICAL STATIONS IN
SAFE HARBOR (NOVEMBER, 1970 TO OCTOBER, 1971).
-------
FIG. 46 MONTHLY AVERAGES OF DIATOM AND PROTOZOAN SPECIES PER 2imn2
AT SAFE HARBOR AND CONTROL STATIONS. EACH MONTHLY RADIUS
REPRESENTS 0 - 100 spp READING FROM THE CENTER.
Each radius is numbered as the hours on a watch and represents
that month.
114
-------
FIG. 47 MONTHLY AVERAGES OF NUMBERS OF DIATOM^
AT SAFE HARBOR AND CONTROL STAT?™
„
™>TOZOAHS PER
Each radius is numbered as the hours on a watch and represents that
month. Values are read from the center to the circumference.
A stations represent 0 - 500 individuals/mm2, B stations 0 - 200
individuals/iam2.
115
-------
10B were in an uncontaminated environment, 7A and 7B were on the
western edge of the turning basin and 3A and 3C were on the channel
wall of the desalination plant.
Species diversity was often greater at the lower stations and the
numbers of individuals per unit area of slide surface were generally
greater at the shallower stations. The number of species shared in
common between any two stations varied considerably. At the highest,
it was 46 percent, Stations IDA and 7A on November 13th, 1970. More
commonly, species shared in common were few and at the lowest 0 percent,
Stations 10A and 7A on December 2nd and December 16th, 1970, between
the same two stations. Stations 3C and 10B have had as much as 17
percent species similarity on December 2nd, 1970 and as little as 9
percent on December 16th, 1970.
Comparison of plots of percent effluent at the stations and the diver-
sity and abundance of organisms on the diatometers showed no clear
relation. Figures 48 and 49 show numbers of Vorticella sp. and
Nitzsehia longissima per mm2 of slide surface settling each month at
Safe Harbor and control stations. Compared to the control station,
both organisms showed an increase in the numbers of individuals at
Safe Harbor shallow stations and a decrease in numbers at the deep
station (3C) in Safe Harbor near the effluent discharge (Table VIII).
TABLE VIII
Mean abundance of a ciliate protozoan (Vort'ioella sp.) and a diatom
(Nitzsohia long-issima) settling per mm2 on diatometers at Safe Harbor
and control stations.
Station Depth Distance from Vort-icella/mm.2 Nitsschia/vm2-
Discharge Point
3A
7A
10A
3C
7B
10B
2.4m
2.4m
2.4m
7.0m
7.0m
7.0m
73m
415m
Control
73m
415m
Control
14
2.7
1.7
2.5
3.9
3.5
73
47
15
1.2
9.5
6.0
Settlements of serpulids, barnacles, and hydroids occurred continuously
on diatometers at Station 3C but did not occur on diatometers at Station
10B. The presence of these filter feeding organisms on the glass slides
adversely affected the diatom and protozoan populations and made inter-
pretation of the results difficult. These filter feeders not only
116
-------
FIG. 48 MONTHLY AVERAGES OF VORTICELLA SP SETTTTwr AT CAT,
AND CONTROL STATIONS. EACH RADIUS SSSSlW 0™*?****
SPECIMENS READING FROM THE CENTER. KilFKJlSENTS ° ~ 20
Each radius is numbered as the hours on a watch and represents
that month.
117
-------
FIG. 49 MONTHLY AVERAGES OF NITZSCHIA LONGISSIMA SETTLING AT
SAFE HARBOR AND CONTROL STATIONS. EACH RADIUS REPRESENTS
0 - 100 SPECIMENS (A STATIONS) AND 0 - 50 (B STATIONS)
READING FROM THE CENTER.
IDA
10B
Each radius is numbered as the hours on a watch and represents
that month.
118
-------
competed for space on the slides but also preyed upon the diatoms
and protozoans, accounting for some of the lower species diversity
values and numbers of individuals at Station 3C compared to the
control station.
IN SITU BIOASSAYS
Echinoids showed greatest sensitivity to the effluent and died
rapidly at Station 3 (the closest biological station to the discharge).
Table IX shows the average number of days echinoids survived at the
three test stations from September, 1970 to June, 1971. The concen-
tration of effluent decreased from an average of 3.8 percent in Dec-
ember, 1970 to 2.1 percent In February, 1971. Even so, echinoids
placed at Station 3 in February died in only three days. In June,
1971, removal of the badly corroded copper-nickel trays from the
desalination plant reduced the copper discharge. Following the lower-
ing of copper content in the effluent, echinoid survival increased
markedly (Table IX).
In Figure 50, the number of days survival of echinoids are plotted
against maximum concentration of effluent during the total period of
exposure. Levels of only 1.5 percent effluent were apparently toxic
to the echinoids. Gorgonians survived brief exposure to four or
five percent effluent and stone crabs tolerated six to seven percent
peaks of effluent concentration. Numerous mortalities are indicated
on Figure 50 during periods of supposedly low effluent concentrations.
As the study progressed, more and more 'unexplained' deaths occurred.
It became evident that the transient peaks of contaminants were criti-
cal and that the sampling technique used for the effluent was not ade-
quate to register these peaks. Average percentage of effluent or
effluent exposure indices showed little significant correlation (P>-20).
Continuous monitoring of the effluent during cleaning operations
showed copper and nickel levels increased markedly in the effluent
for about twenty-four hours after the plant resumed operation (see
discussion in Section VI Copper and Nickel). Because of the low
salinity of the effluent when the plant first began operation, the
discharge readily mixed with the ambient water and did not stratify.
As a result, shallow water stations, as well as deep water stations,
received high concentrations of copper every time the plant began
operating again after a maintenance period.
High copper levels were frequently associated with mortalities of the
echinoids. On January llth, 1971, for example, the copper concentra-
tion at Stations 7A and 7B increased 100 percent over the December
1970 average. The following day one echinoid at 7A and two at 7B were
dead. All of the echinoids at Stations 3A and 3C died the same day.
119
-------
TABLE IX
SURVIVAL OF ECHINOIDS AT BIOLOGICAL STATIONS
SEPTEMBER, 1970 TO JUNE, 1971
STATION AVERAGE DAYS SURVIVED NUMBERS OF INDIVIDUALS
3A 15 41
3C 9 52
7A 49 19
7B 21 30
IDA 130 1 (All others still
1iving s ince
10B 38 1 10/23/70)
SURVIVAL OF ECHINOIDS AT BIOLOGICAL STATIONS
JUNE, 1971 TO OCTOBER, 1971
STATION AVERAGE DAYS SURVIVED NUMBERS OF INDIVIDUALS
3A 63 6
3C 17 17
7A 81 7
7B 118 5
120
-------
10-1
3C
8 •
UJ
=
°
°- 1 } 1 1
2 I 4lHi
o 61 11 .
z 11 l}l
I ,1- ""
I UMii
3 4 n 4 "*
u_ 1
t
§ i
QC
LU 1
x A
1 2 lll 22 2
<
Z 22
1 , , " 3
0-122 22 3 £ 3 5
I 22
2 = 3A
3 = 7A
4 = 7B
5 = 8
4
33
332 525 22 3 ^
10
20
50
60
30 40
DAYS SURVIVAL
FIG. 50 ECHINOID SURVIVAL VERSUS MAXIMUM PERCENT EFFLUENT DURING EXPOSURE
70
80
-------
On January 25th, the desalination plant was unstable and discharged
6,512 ppb copper. On the following day the remaining echinoids at
Station 7 died. One of these animals had been at that station 170
days, one 80 days, and two 39 days. The copper concentration more
than doubled at Station 7 on that day and there was no assurance
that the sample was taken when the highest level of copper reached
the station.
Correlations between copper levels at the stations and echinoid
mortalities, however, were not significant (P>.20) suggesting that
sampling frequency was not suitable, especially from November, 1970
to October, 1971 when the plant was frequently shut down for mainte-
nance.
It became evident that the transient high peaks of copper released
when the plant started operations were causing more mortalities of
experimental animals than extended exposures to effluent during normal
operation of the desalination plant. To test this hypothesis, the
dates on which echinoids died were compared with the operation of the
desalination plant. The four operating conditions chosen for compari-
son with mortalities were; 0 to 2 days following start-up, 0 to 2 days
following shut-down, unstable operation, and normal plant operation
(+2 days). The results are presented in Table X. Not one echinoid
died while the plant was operating normally from October, 1970 to
October, 1971. At Stations 3A, 3C, and 7A about 60 percent of the
test animals died within two days following start-up of the desalina-
tion plant.
Surprisingly, a large percentage of deaths occurred following shut-
downs. The causes of these mortalities are not clear. On one occasion
(April 27th, 1971), two echinoids died at Station 3A following low pH
discharges from cleaning of the evaporator just prior to shut-down.
Plant operators insisted that this was not a common procedure and pH
recordings taken during the study supported this. Low pH conditions
within the plant were shown to increase copper discharge and this
might account for some of the mortalities prior to shut-down periods.
In many instances, however, mortalities could not be explained.
It should be noted that the arrangement of the discharge pipe and the
sampling pipe prevented sampling of the effluent when the plant was
being shut-down. At these times, the discharge pipe would empty. To
avoid damage to the sampling system pump, which was not designed to
operate dry for extended periods, the continuous sampling system was
shut down when the plant was secured and turned on when operations had
started again.
Many shut-down periods were caused by a blown tube in the boiler and,
after the facility was secured the boiler was allowed to cool and then
the water in the boiler was released. The boiler water amounted to
about 5,000 gallons and had a pH of about 10. It was high in phosphates
122
-------
TABLE X
Percentage of echinoid deaths related to start-ups, shut-downs,
unstable plant operation or normal operation of the
desalination plant from October, 1970 to October, 1971.
STATION 0-2 DAYS 0-2 DAYS 0-2 DAYS PLANT
AFTER AFTER UNSTABLE OPERATION
START-UP SHUT-DOWN OPERATION NORMAL
3A
3C
7A
7B
60%
66.7%
66.7%
18.5*
37.1*
0
1.9*
lit.81
17.2*
0
0
0
0
123
-------
and sulfates to prevent scale build-up. The low density of the water,
however, made the 5,000 gallon discharge float and it should not have
caused mortalities at the deeper stations. Table X, however, shows
mortalities in the deeper water were related to events surrounding
the shut-down periods, and that Stations 7A and 7B were also influenced.
The discharge from the boiler was probably too limited a volume to
influence Station 7.
It was abundantly clear, however, that start-ups and shut-downs were
intimately associated with the mortalities at the biological stations
and that transient, high-level peaks of contaminants were more dele-
terious to the biota than steady-state operating conditions. The
sampling program focused on steady-state, long-term conditions and
was not designed to follow, and detect, sudden transients in levels
of contaminants.
Although the plant operators were extremely cooperative during the
course of the study, the investigators were not frequently able to
obtain advance notice of when the plant would actually begin, or cease
operation so that they could be on site for complete following of
events. Most of the shut-downs were completely unpredictable, especially
when caused by unexpected blown boiler tubes or other emergencies. Sim-
ilarly, start-ups began as soon as repairs were completed and it was
often impossible to know in advance when a blown tube would be found
and repaired or when a pump would be made operational again. Conse-
sequently, only a few times during the study period could the research
team plan an adequate investigation of the transient peaks.
In spite of this problem, plots of maximum effluent exposure against
mortalities did produce a reasonable pattern and the numerous deaths
shown in Figure 50 which appear unrelated to percentage of effluent
exposure are a reflection of unmeasured transient peaks of contaminants.
Since survival increased markedly when copper levels were reduced in
June, and since copper was the major contaminant during start-up periods,
it can be assumed the most deleterious constituent of the transient peaks
was copper.
Figure 51 shows a plot of the average number of days of gorgonian
survival at Stations 2 through 7, compared with the average concentra-
tion of effluent at the "B" stations from August, 1970 to March, 1971.
The solid line, representing days of survival at "B" stations, is clearly
inversely related to the amount of effluent present. As the effluent
concentration increased, survival decreased. Survival at the "A" series
stations is also plotted and shows a similar dependence on the effluent
concentration. Survival was greater at the "A" series stations since
the effluent concentration*was also less at these upper stations.
124
-------
100
80
60
<
o
20
3 4
\
STATION A
STATION B
GORGONIANS
• .STATION B EFFLUENT
2000
1000
1000
2000
STATION
8. NUMBER
"O
rn
73
m
3000 FEET FROM
DISCHARGE
FIG.51 AVERAGE NUMBER OF DAYS SURVIVED BY GORGONIANS (PTEROGORGIA ANCEPS) AT "A" SERIES STATIONS
FROM AUGUST, 1970 TO MARCH, 1971 AND AVERAGE PERCENT EFFLUENT AT "B" SERIES STATIONS
DURING THIS PERIOD
-------
LABORATORY BIOASSAYS
Static 96-hr TLm acute bioassays (Standard Methods 1965) were
conducted as shown in Figure 7. The -in situ transplanting of
organisms described above was designed to test the toxicity of the
effluent on organisms under natural conditions. Laboratory
experiments were performed only as a method of identifying the
most toxic constituent in the effluent.
Initially, acute toxicity was determined for dilutions of the
unaltered effluent. Samples of effluent were diluted with ambient
water taken upcurrent from Safe Harbor. Ten, 50-liter glass aquaria
were set up with various dilutions of the effluent and a natural
seawater control. For experiments with echinoids (Lyteohinus 'varie-
gatus), crabs (Menippe meTcenavid), ascidians (Ascidia nigva), and
gorgonians (Pterogorgia anceps\ ten experimental animals were used
per tank (this being the largest number which survived well in the
50-liter aquaria). Turtle grass (Thalassia testudimm) was analyzed
in a different set-up (see Section IV Methods and Procedures).
Analysis was complicated by the varying characteristics of the
effluent, particularly in regard to copper concentration. The data
plotted in Figures 52 through 55 represent resistance to effluent
taken after the plant was operating at 80 to 90 percent load for
more than 48 consecutive hours.
These data were plotted as recommended by Standard Methods 12th
Edition, 1965 to interpolate 48 and 96-hr TLm's. It is recognized
this method has been validly criticized, i.e. (Wilber, 1965) as not
representative of effluent toxicity in the natural environment and
that it is not statistically sophisticated. The method was used
in this study for the express purpose of determining approximate,
relative toxicological values to aid in identifying the more
deleterious constituents of the effluent. The 48 and 96-hr TLm
values given here are not intended to be representative of the
toxicity of desalination plant effluents, especially since the
toxicity varied greatly during the course of the study due to
fluctuations in copper content.
Asoidia nigpa had the least tolerance to the effluent with 50 percent
of the test animals dying after a 96-hour exposure to 5.8 percent
effluent (Fig. 52). Lytechinus variegatus showed a similar
sensitivity with a 96-nr TLm value for 8.8 percent effluent (Fig.
53). Menippe meroenaria had a 96-hr TLm value for twelve percent
effluent (Fig. 54). Photosynthetic activity of specimens of Thalassia
testudinum was depressed by 50 percent in 24 hour exposure to 12
percent effluent (Fig. 55).
To determine if temperature, salinity, or copper (the three major detri-
mental factors identified in the effluent analyses) were responsible for
126
-------
0
CC
I UN(GATES (Aseidia nigra)
X = 48-hr survivors
0 = 96-hr survivors
10
40 50 60
PERCENT SURVIVAL
100
FIG.52 48 and 96-HOUR TLm ACUTE BIOASSAY OF DESALINATION PLANT EFFLUENT
ON ASCIDIA NIGRA.
127
-------
30 *
25
20
ECHINOIDS (Lyteahinus variegatus)
X = 48-hr survivors
0 = 96-hr survivors
15
12.7
48-hr TLm
10
\96-hr TLm
10 20 30 40 50 60
PERCENT SURVIVAL
70
80 90
100
FIG. 53. 48 AND 96-HOUR TLm ACUTE BIOASSAY OF DESALINATION PLANT EFFLUENT
ON LYTECHINUS VARIEGATUS.
128
-------
UJ
o
35
30
25
20
15
12
10
"C
96-hr TLm
TLm
STONE CRABS (Menippe meraenaria)
X = 48-hr survivors
0 = 96-hr survivors
10
20
30
50
60
70
80
90
100
PERCENT SURVIVAL
FIG. 54. 48 AND 96-HOUR TLm ACUTE BIOASSAY OF DESALINATION PLANT EFFLUENT
ON MENIPPE MERCENARIA.
129
-------
30
25
TURTLE GRASS
(Thalassia testudinun)
20
15
12
10
24-hr 501 depres
* \ on
10 20 30 40 50 60 70
PERCENT RESIDUAL PHOTOSYNTHESIS
80
90
100
FIG.55
24 HOUR, 50 PERCENT REDUCTION OF PHOTOSYNTHETIC RATE OF THALASSIA
TESTUDINUM EXPOSED TO VARIOUS DILUTIONS OF DESALINATION PLANT EFFLUENT.
130
-------
observed mortalities, each of these parameters was raised indepen-
dently in separate analyses (Fig. 7). Salinity, even when raised
to the equivalent of 30 percent effluent (40.2 o/oo) produced no
mortalities. '
Copper was added to seawater as the cupric sulfate salt (CuS045H?0)
and its toxicity tested using the same 96-hr static acute bioassay
methods. Results of these bioassays were compared with bioassays
of equivalent amounts of copper found in the dilutions of effluent
(Figs. 56 through 59). Figure 56 shows that 100 ppb copper was
present in the effluent dilution which caused 50 percent of the
echinoid mortalities in 96 hours and that the toxicity of 105 ppb
cupric copper in normal seawater was sufficient to cause the same
mortality. Copper, therefore, was the sole toxic constituent in
the effluent required to explain the observed echinoid mortalities.
Similar results were found in the copper toxicity experiments with
stone crabs (Fig. 57) and turtle grass (Fig. 58), although these
organisms were on the whole less sensitive to copper than either
echinoids or ascidians.
Copper toxicity did not explain all of the observed toxic effects
of the effluent for specimens of Ascidia nigra (Fig. 59). One
hundred and fifty ppb ionic copper were required to kill 50 percent
of the experimental specimens of A. nigra when the copper was dis-
solved in seawater but the same mortality occurred with effluent
which contained only 80 ppb copper. Ascidia nigra, therefore, was
also sensitive to some other contaminant of the effluent, or to the
interaction of the various contaminants. Zeitoun et al (1969),
Lloyd (1965) and others have shown synergistic effects of copper
with temperature and perhaps these are more pronounced for the filter
feeding ascidians than for the other organisms tested. Alternatively,
other contaminants in the effluent (i.e., nickel) may have had a
greater affect on A. nigra than on the other organisms.
Although temperature tolerance tests showed the experimental organisms
were within a few degrees of their lethal limits, the temperature
elevations caused by the 96-hr TLm dilutions were within normal sea-
sonal ambient ranges. Temperature, by itself, was not lethal to the
test animals at the 96-hr TLm effluent dilutions. Ascidia nigra and
Lytechinus variegatus showed an abrupt increase in mortality at
about 32°C. At temperatures at or below 31°C all specimens of both
species survived more than 96 hours. When temperatures were at or
above 32°C more than 50 percent of the experimental specimens of both
species died within 96 hours.
A temperature of 32°C represents the heat of an effluent dilution of
20 percent in the acute bioassay experiments. Since the 96-hr TLm
dilution of the effluent for L. variegatus w^*9*?*
31°C) and that for A. nigra about 6 percent (about 30.5 C) ,
ture alone could not account for the observed mortalities.
131
-------
.o
Q.
Q.
JUU
250
200
150
105
100
90
80
70
i
X
^ 96-hr TLm
^ 96-hr TLm ^^-^
ECH 1 NO 1 DS (Lyteahinus variegatus )
X = Cu added to ambient
seawater
0 = Cu in effluent mix
""\
\
^
^^"o
10 20 30 40 50 60 70
PERCENT SURVIVAL
80
90
100
FIG.56 COMPARISON OF TOXIC EFFECTS OF COPPER IN EFFLUENT (0) AND IN
SEAWATER (X) ON LYTECHINUS VARIEGATVS.
132
-------
600
550
500
450
400
350
o 300
o
_o
Q.
Q.
250
200
150
96-hr TLm
36-hr TLm
STONE CRABS (Menippe meraenaria)
X = Cu added to ambient
seawater
0 - Cu in effluent mix
10
20
30
1*0 50 60
PERCENT SURVIVAL
70
80
90
100
FIG 57 COMPARISON OF TOXIC EFFECTS OF COPPER IN EFFLUENT (0) AND IN
SEAWATER (X) ON MENIPPE MERCEMPIA.
133
-------
500 *
a.
a.
o
o
a.
a.
TURTLE GRASS (Thalassia testudinwri)
X = Cu added to ambient
seawater
0 = Cu in effluent mix
24-hr 50% depre
24-hr 50% depre
100
30 40 50 60 70
PERCENT RESIDUAL PHOTOSYNTHESIS
FIG.58 COMPARISON OF TOXIC EFFECTS OF COPPER IN EFFLUENT (0) AND IN
SEAWATER (X) ON PHOTOSYNTHETIC RATES OF TRALASSIA TESTUDINUM.
100
134
-------
300
250
200
150
CL
O.
o
a
a.
100
90
80
70
'96-hr TLm
TUN I GATES (Asoidia nigra )
X = Cu added to ambient
seawater
0 = Cu in effluent mix
10 20 30 40 50 60
PERCENT SURVIVAL
70
80
90
100
FIG59 COMPARISON OF TOXIC EFFECTS OF COPPER IN EFFLUENT (0) AND IN
SEAWATER (X) ON ASCIDIA NIGRA.
135
-------
Similarly, M. mercenaria showed a 96-hr TLm between 32 and 33°C,
while the 96-hr TLm effluent dilution temperature was about 31.5°C.
Experiments conducted with the gorgonian, Pterogorgia anceps, were
unsatisfactory. The investigators were unable to establish satis-
factory criteria for colony death. Frequently gorgonian specimens
in higher effluent concentrations would withdraw their polyps and
remain in this retracted position. There was no way to determine
when the animals actually died until decomposition of the colony was
well advanced. The rate of decomposition was also influenced by the
concentration of the effluent. Dead gorgonian specimens placed in
dilutions of 5 to 10 percent effluent decomposed more rapidly than
those in 20 to 50 percent effluent dilutions. Some dead specimens
placed in 50 percent effluent did not show signs of decomposition
after 96 hours.
Copper was the most deleterious constituent of the desalination plant
discharge as revealed by the laboratory bioassays. Copper probably
was responsible for most of the observed changes in the Safe Harbor
biota reported above. The small changes in temperature and salinity
(Fig. 12) produced by the effluent were well within normal seasonal
variations and within the tolerance limits of experimental animals
in the static bioassay tests.
The amounts of copper discharged by the desalination plant frequently
increased copper concentrations at the stations to levels shown to
be toxic by acute bioassays. This was especially true during periods
when the plant was beginning operations following a shut-down. During
the acute bioassays, copper concentrations of only 250 ppb ionic
copper caused 50 percent echinoid mortality in 17 hours. Copper con-
centrations up to 359 ppb were recorded at the i-n situ bioassay stations
on days when the experimentally held animals died at those stations.
Copper concentrations as high as 538 ppb copper were found at biologi-
cal stations 3A and 3C associated with the turbid effusions following
start-ups of the desalination plant.
COPPER TOXICITY
Copper toxicity in the marine environment has been studied by numerous
workers. The literature has been recently reviewed by Raymont and
Shields (1964), Le Gros et aZ (1968), Zeitoun et al (1969B), Lloyd
(1965). Additional studies include those of Portman (1968) and Hueck
et al (1968).
Galtsoff (1943) reported nearshore copper values of 0.01 and 0.02
ppm and emphasized that levels of this magnitude were required for
physiological requirements of many marine invertebrates. Brooks and
Rumsby (1965) and Galtsoff (1964) and others have demonstrated copper
136
-------
is actively accumulated in the tissues of marine invertebrates and
copper levels of 8 to 80 ppm have been reported in oysters from
unpolluted areas. Copper concentrations from 120 to almost 400 ppm
have been reported in oysters from polluted waters.
While copper in organic form does not appear to be excessively
toxic, inorganic ions of copper are toxic to a wide variety of verte
brates and invertebrates. Toxicity of copper varies significantly
between various species of organisms and with different physical
and chemical properties of the water. Portman (1968), Lloyd (1965),
and Zeitoun et al (1969) have discussed the synergistic relationship
between copper toxicity and zinc, cadmium, mercury, and temperature
and the antagonistic effects between copper toxicity and calcium as
well as salinity.
Zeitoun et al (1969) found cultures of dinoflagellates died when
exposed to copper concentrations of 0.05 ppm ionic copper as did
two species of blue-green algae. Diatoms and green algae showed
varying susceptibilities to copper ions ranging from 0.05 to 0.5
ppm. Miller (1946) found the bryozoan Bugula neritina could live,
but not grow, in copper concentrations of 0.2 to 0.3 ppm and that
their larval stages died at copper concentrations in excess of 0.3
ppm. Galtsoff (1932) found oysters were killed by 0.1 to 0.5 ppm
copper ions. Bernard et al (1961) found that cyprids of the barn-
acle Balanus amphitrite n-tveus could survive but not settle in
copper solutions of 0.5 to 10 ppm copper. North (1964), and Clen-
denning and North (1960) found only 0.1 ppm copper was sufficient
to cause reduction in photosynthetic rate of the kelp (Macroaystis
Several species of fish and invertebrates were collected in Safe
Harbor and at the control stations off Boca Chica Island for analyses
of copper content. Collections of fish made simultaneously, in par-
ticular the goby (Lophogobius oyprinoides ) , were specially prepared
for histological and histochemical analyses. The laboratory work
was performed by G.R. Gardner at the National Marine Water Quality
Laboratory in Rhode Island. Preliminary results showed that the
gobies had an abnormal liver condition with highly vacuolated hepa-
tic cells and unusual hepatic lesions. The rubeanic acid histo-
chemical process showed copper deposition in the livers of fish from
Safe Harbor; all but two of which had hepatic lesions. Two sets of
collections were made. In the first, lesions were restricted to fish
from Safe Harbor and all control fish were normal. In the second
collections, however, three animals from the control station had
lesions. During the period between the two sets of collections, the
U.S. Navy had dumped a considerable amount of solid waste in the
immediate vicinity of the control station. Some of the gobies may
have been adversely affected by living in the submerged waste
Additional experiments are in progress to confirm the lesions are
copper induced (Gardner, personal communication).
137
-------
During the gathering of growth and survival data on Ascidia nigra,
divers noted animals in protected environments survived better and
grew faster than those in exposed locations. A survey of other
copper sensitive organisms in Safe Harbor confirmed that those in
sheltered, dark locations (under ledges, in caves, and behind sub-
merged structures) also were larger and settled more densely than
those in illuminated habitats. The same relationship did not appear
in sites beyond the extent of the effluent.
According to Steemann Nielsen and Wium-Andersen (1970), copper toxicity
occurs in Chlorella only in the light. When Chlorella were treated
with copper but left in light-proof containers, they experienced no
toxic effects until exposed to light. Perhaps a similar mechanism
influences copper toxicity in invertebrates.
Normally, Ascidia nigra, which is a filter feeder, grows faster in
unsheltered environments, where currents can circulate more freely.
In the copper-rich Safe Harbor environment, however, animals pro-
tected from strong light outgrew those in more exposed positions.
The effect of light on copper toxicity may explain this phenomenon
and may also explain the settlement and success of organisms on only
the lower surfaces of settlement panels. During the preliminary survey,
Clarke (unpublished data), organisms settled equally successfully on
the top and bottom of panels. From August, 1970 to August, 1971 the
upper surfaces of the settlement panels were almost entirely barren of
organisms after the normal exposure period, while serpulids, sabellids,
and barnacles grew rapidly on the lower surfaces.
To determine if copper uptake and toxicity were influenced by illumi-
nation, specimens of A. nigra were collected from the desalination
plant sea wall and from the control station in September, 1971.
Specimens from the sea wall were collected from exposed, highly illumi-
nated areas as well as from the dark situations in crevices in the sea
wall. These were analyzed for total copper content by the method
described in Appendix A.
Copper concentration in A. nigra specimens from the control station
averaged 39 ppm; a concentration 2,300 times the ambient copper levels
found in seawater at that station during the preceding four months.
Copper concentrations in specimens from the illuminated portions of
the sea wall at the desalination plant averaged 202 ppm; a concentra-
tion of 5,000 times the levels recorded in the water at that station
during the months that A. nigra commenced resettling on the wall. The
copper levels recorded from water at the sea wall station were, how-
ever, lower than actually occurred there during the periodic, trans-
ients of high copper concentrations associated with effusions follow-
ing maintenance periods. The specimens collected from darkened crevices
had copper concentrations of 132 ppm. The following findings emerge
from these analyses:
138
-------
1. A. nigra collected from illuminated areas along
the desalination plant sea wall had more than
five times the copper concentration found in
specimens collected at the control stations.
2. A. nigra collected from illuminated areas had
1.5 times the amount of copper found in the
specimens collected from crevices along the
sea wall.
The ten largest specimens collected from illuminated areas had an
average volume of 2.5cc. The ten largest specimens collected from
dark crevices had an average volume of 6.2cc. Since settlement of
these animals occurred in the first part of August (about 30 days
prior to collection), it can be assumed that the A. nigra in the
darker areas grew about 2.5 times more rapidly than those in the
illuminated areas.
It can be concluded from the results of the A. nigra studies that
copper was concentrated at a higher rate and was probably more toxic
in illuminated versus dark habitats. The mechanism for this metabolic
difference is not known, but illumination should certainly be considered
a key parameter when conducting copper toxicity studies either in the
laboratory or in the field.
Correlations between the biological data and copper concentrations
recorded from the regular hydrographic samples were poor. As stated
above, this was due to periodic effusions with high levels of copper
which were (because of their brevity) impossible to measure in situ
at the biological stations. Only organisms which could avoid the
effusions would be expected to show a good correlation with the average
copper levels recorded at the biological stations. Barnacles showed
this conclusion to be true. Barnacles are able to completely seal their
shells with their operculum. When shut, the operculum protects the
barnacle from dessication at low tide or osmotic stress during expo-
sure to freshwater. Divers, during the study, noticed that the barna-
cles closed their opercula and ceased feeding when exposed to turbid
effusions containing high copper concentrations. Barnacles and ser-
pulids are the only surviving sessile organisms at Station 4, immed-
iately in the path of the discharge and their success at that station
may be due to their ability to isolate themselves from the effluent
when necessary.
When 30-day settlement discs were analyzed, the largest barnacles
were measured to obtain an estimate of maximum barnacle growth
during that month. These growth rates were plotted against average
copper concentrations found at biological stations by regular sampl-
ing (Fig. 60). Two groups of stations were selected; Stations 3, 5,
and 6 near the effluent and Stations 2 and 7 farther away (see Fig.
3). The regression lines shown in Figure 60 do not differ significantly
in slope or elevation (P>.20 in a two-tailed F test), but do differ
139
-------
10
3
O
cC
ts
o
<
z
CC
<
CO
X
<
<
o
o
0 =
X =
Stations 3A, 3C, 5A,
5B, 6A, 68
y = 9.1 - 0.0502b
r = 0.8633
Stations 2A, 2B, 7A,
y = 9.58 - 0.0889b
r = 0.7782
7B
20 40 60
AVERAGE MONTHLY COPPER (ppb)
80
100
FIG. 60 MAXIMUM MONTHLY BARNACLE GROWTH COMPARED TO TOTAL AVERAGE
DISSOLVED COPPER EXPOSURE, APRIL, 1971 TO OCTOBER, 1971.
-------
The regression lines shown in Figure 60 do not differ significantly
in slope or elevation (P>.20 in a two-tailed F test), but do differ
significantly (P>0.01) in residual variances. Correlation coefficients
for the two groups of data are 0.863 (significant at P>0.01 level) for
Stations 2 and 7.
Since it was already established that the regular hydrographic sam-
pling did not detect transient peaks, the copper concentrations
shown in Figure 19 were primarily representative of steady-state
conditions. Their significant correlation with the growth of the
barnacle, Balanus conphitrite, substantiated the hypothesis that these
barnacles were able to detect and isolate themselves from high copper
concentrations associated with the periodic effusions. It also demon-
strated the toxicity effects of copper on this species. Bernard et al
(1961) demonstrated that larvae of B. amphitrite can not attach in
copper concentrations in excess of 0.024 ppm using laboratory cultures.
Since copper levels were never recorded that low at the point of ef-
fluent discharge, it must be assumed that larvae were more successful
in settling in the natural environment than in laboratory cultures.
Probably, settlement and metamorphosis occurred during periods when
the plant was not operating.
A comparison of copper concentrations in a variety of fish was made
to determine if levels were elevated in Safe Harbor fish compared to
control station fish and if predatory fish contained more copper than
herbivorous fish. Unfortunately, there was no method to determine the
length of time a particular specimen had been feeding in the harbor.
Spade fish (Chaetodipterus faber) tended to be a transient species
along the desalination plant sea wall which fed on polychaetes, barna-
cles, and algae. Specimens speared adjacent to the effluent contained
8 ppm dry weight copper in the flesh and 34 ppm dry weight copper in
the liver. Sheepshead (Archosargus probatoaephalus) were almost always
seen during dives and probably resided in the canal. Sheepshead fed on
the same organisms as spade fish and specimens speared near the desali-
nation plant had 7.2 ppm dry weight copper in the muscle tissue and
369 ppm dry weight copper in the liver tissue. Specimens of the same
species from the control station had 6.9 ppm dry weight copper in the
muscle and 30 ppm dry weight copper in the liver.
Other fish examined showed similar low copper levels in the flesh but
high copper levels in the stomach and liver tissues. Since copper is
an essential element for numerous physiological processes in organisms
it was not surprising to find the low levels in muscle tissues. High
levels of copper can be accepted by animals when in the organic form,
and excess organically chelated copper can be eliminated by normal
metabolic processes.
Spector (1956) lists some of the physiological functions of copper as:
erythropoiesis myelinization of the central nervous system, mainte-
nance of several enzyme systems (polyphenol oxidase, tyrosinase,
141
-------
laccase, catechol oxidase, and ascorbic acid oxidase), a component
of hemocyanin, hepatocuprein and the hemocuprein-protein complexes
found in liver tissue, to name a few. Relatively high levels of
copper are regularly assimilated by animals and the Department of
Health, Education and Welfare, Food and Drug Administration have not
found it necessary to set a maximum limit for copper in foods (A. A.
Russell, Bureau of Foods, personal communication). When ingested or
absorbed in the ionic form, however, copper becomes toxic and its
reaction with biological systems is generally attributed to damage
to cellular membranes due to complexing of the copper with lipid
factions of the cell wall and subsequent interference with ion trans-
port (Zeitoun et al 1969).
Because of the physiological ability to metabolize ingested, organ-
ically complexed copper it can be expected that copper will not show
appreciable biological magnification in the predator-prey relation-
ships. The work of Hueck and Adema (1968) on the role of copper
toxicity in the predator-prey relationship of Daphnia and algae,
although preliminary in nature, tends to confirm this hypothesis.
142
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SECTION IX
ACKNOWLEDGEMENTS
Westinghouse Ocean Research Laboratory (WORL) is grateful to the
Environmental Protection Agency for the financial support and
technical guidance of this study. Funds were supplied under E.P A
Contract Number 14.12.888. Dr. J. Frances Allen, Dr. Richard Wade',
and Dr. Roy Irwin were project officers and their guidance and
interest in the program were greatly appreciated.
WORL also thanks the Florida Keys Aqueduct Commission, particularly
its chairman, John M. Koenig, for permission to work closely with
the operators of the Key West Desalination Plant and for the generous
use of their property for the installation of laboratory equipment
and to conduct of biological experiments. Their cooperation reflects
the genuine concern of the Commission for the environmental well-being
of the nearshore Florida waters.
Lester Chillcott, the Westinghouse Plant Manager of the desalination
facility, was especially helpful during the course of the study. His
expert knowledge of the engineering aspects and operation of the de-
salination plant was of inestimable value in assessing the operational
modes of the desalination plant which might affect the environment.
Like the members of the Florida Keys Aqueduct Commission, Mr. Chillcott
was vitally concerned about the environmental impact of the effluent
and was as interested as the researchers in correcting deleterious
effects.
George Smith, Plant Foreman for the Florida Keys Aqueduct Commission
and the other members of the operational staff were also concerned
about the results of the survey and their cooperation was greatly
appreciated.
Dr. C.P. Tarzwell and George Gardner of the E.P.A. National Marine
Water Quality Laboratory, cooperated extensively in the analysis of
histological effects of copper toxicity on fish from Safe Harbor.
Dr. E.F. Corcoran of the Rosenstiel School of Marine and Atmospheric
Sciences (RSMAAS) performed analyses of copper and nickel content in
samples from the survey and provided insight into some of the toxic
and chemical characteristics of these elements. Dr. 0. Joensuu (RSMAAS)
analyzed the effluent samples by emission spectroscopy and atomic
absorption for a variety of elements. Dr. Wayne Bock (RSMAAS) analyzed
the foraminiferan fauna from sediment samples and from core samples.
Charlene D. Long from the Museum of Comparative Zoology at Harvard
University identified the annelid worms collected in Safe Harbor and
143
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Dr. P.M. Bayer (RSMAAS) identified the gorgonian fauna from the
flats adjacent to Safe Harbor.
Several members of the staff of the Florida Keys Junior College
(where WORL had an analytical laboratory) were helpful during the
study and WORL thanks them for their cooperation.
The author thanks Dr. J.C.R. Kelly, Jr., Director of WORL for his
advice and especially thanks the staff of the Florida Office of
WORL for their dedicated efforts toward the completion of this project.
All of the final drawings and manuscript preparations were done by
Fay Brett. She and Charles Hamlin, Field Engineer for WORL at Key
West, put in many long hours of difficult work beyond normal work
hours and their efforts were deeply appreciated.
144
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SECTION X
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148
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SECTION XI
APPENDIX A
Procedures of copper analysis (by E.F. Corcoran, Resenstiel
School of Marine and Atmospheric Sciences, University of Miami).
The basic neocuproine techniques used by Alexander and Corcoran
(1967) were modified as follows for analyses of water, sediment
and organic tissues for copper content:
1. Glassware Cleanliness: Clean glassware was considered of
prime importance and each piece of chemical glassware was
washed in a hot solution of Liquinox then rinsed with tap
water. To remove remaining detergent, the glassware was
rinsed with ethanol and again with tap water. Acid soluble
metal ions were removed with acid wash then rinsed with
distilled water. A 1 percent solution of disodium salt of
EDTA was placed in the flasks and they were autoclaved at
248°F at 15 p.s.i. for fifteen minutes. The EDTA solution
was removed and the glassware rinsed three times with
distilled, deionized water.
2. Reagents: Sample blanks were kept as low as possible and
reagents were selected carefully-
Distilled water - all reagents were prepared with glass-
distilled water further purified by passage through a
Barnstead cation exchange resin.
Neocuproine 0.1% - Ig of neocuproine was dissolved in 1
liter of redistilled ethyl alcohol.
Hydroxylamine hydrochloride 10% - 100 g of hydroxylamine
hydrochloride was dissolved in 600 ml of distilled water
and filtered through a Whatman GF/C filter pad. Five ml
of 0.1% neocuproine were added to the solution and extracted
with chloroform. Extractions were continued until the
chloroform layer remained colorless. A final extraction
was made with carbon tetrachloride and the hydroxylamine
hydrochloride solution was diluted to 1 liter.
Sodium acetate, Crystal reagent grade 27.5% - 453 g of
sodium acetate was dissolved in 800 ml distilled water
and filtered through a Whatman GF/C filter pad. Two
ml of hydroxylamine hydrochloride and 5 ml of 0.1%
neocuproine were added. The solution was purified as
149
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above, and after all traces of copper were removed, the
solution was diluted to 1 liter.
Perchloric Acid 70-72% - Reagent grade Baker analyzed
#9652.
Standard Solution - 113.36 mg of fine granular copper
metal (Mallinkrodt Analytical Reagent) was dissolved
in 6 ml of a nitric-sulfuric acid mixture (1+1).
The solution was heated to dense fumes of sulfuric acid,
cooled and diluted to 1 liter. This solution contained
113.36 yg/ml. A substandard solution was prepared by
diluting 1 ml of the stock solution to 1 liter. This
solution contained 0.113 yg Cu/ml. The standard curve
was prepared by taking suitable subsamples of the
dilute solution to cover the working range (zero to
50 yg/liter was sufficient for most seawater samples).
3. Procedures:
Water Samples; Digestion - add 3 ml perchloric acid
to 25 ml of sample and cover with watch glass. Place
on hot plate and boil slowly until almost dry. Add
25 ml distilled deionized water and dissolve precipi-
tate completely-
Add reagents in the following order:
a. 2 ml hydroxylamine hydrochloride
b. 5 ml neocuproine solution
c. 10 ml sodium acetate solution
Swirl sample between each addition. Allow fifteen minutes
for color development.
Optical density was measured at 454 my in a Beckman
DU spectrophotometer with 10 cm cells.
Sediment Samples: 200 mg of dried sediment was
pulverized with mortar and pestle and digested as
above with 3 ml of perchloric acid. Analysis then
proceeded as with water samples.
Tissue Samples: The tissue was macerated and an
aliquot selected and dried to obtain the dry versus
wet weight. 3 ml of perchloric acid was added to
a wet aliquot and the samples were treated as
described for water samples.
150
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j Accession Number
w
2 Sa&ject Field & Group
053
- j Organization "" "•*
•• •••' WESTINGHOUSK firRAM PPCE-ADi-iu T
SELECTED WATER RESOURCES ABSTRACTS
INPUT TRANSACTION FORM
10
ANNAPOLIS, MARYLAND. 21404
Title
BIOLOGICAL IMPACT OF A LARGE-SCALE DESALINATION PLANT AT KEY WEST
Authors)
RICHARD H. CHESHER
*
16
18080 GBX
21 I Wote — — •
22
Citation
23
Descriptors (Starred First)
Water pollution effects*, desalination plants*, biological communities*,
copper toxicity*, thermal stratification, subtropic.
25
Identifiers (Starred First)
Key West*, multi-stage-flash evaporation process.
27
Abstract
An eighteen month biological study showed the heated brine effluent from a
desalination plant in Key West, Florida caused a marked reduction in biotic diversity.
Some organisms were more abundant in the receiving waters than in control areas but
these were generally capable of isolating themselves from the effluent by closing up
or by moving to other areas during periods of high contamination. Ionic copper, dis-
charged from the plant, was the most toxic feature of the effluent. Temperature and
salinity of the effluent and the receiving water were such that the effluent stratified
at the bottom of the receiving basin. This stratification reduced water circulation
and the man-made harbor acted as a settling basin which lessened the impact of the dis-
charge on surrounding natural environments.
Periodically, the plant shut down for maintenance or cleaning. When it resumed opera-
tions, low temperature water of ambient salinity was discharged which was highly con-
taminated with ionic copper. These sudden effusions caused more biological damage
than steady-state conditions. At the end of the study, extensive engineering changes
were made to correct corrosion problems and lower copper discharge.
This report was submitted in fulfillment of Contract No. 14.12.888 under the sponsor-
ship of the Environmental Protection Agency.
Abstractor
WR:I02 (REV. JUUY
WRS1C
Institution
SEND. WITH COPY OF DC
FNT TO: ,.AT6B RESOURCES SCIENTIFIC INFORMATION CENTER
. ^^ DEPARTMENT OF THE INTERIOR
WASHINGTON, D. C. 20240
GPO: 1970 - 407 -631
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