I! PA 909/9-74-003 ¥ m* ro
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o
SHELLFISH STUDY
OF
SAN FRANCISCO BAY
APRIL - JUNE 1972
TECHNICAL REPORT
U.S. Environmental Protection Agency, Region IX
Surveillance and Analysis Division
San Francisco, California 94111
June 1974
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DISTRIBUTION STATEMENT
Document is available to the public
through the National Technical Infor-
mation Service, Springfield, Virginia
22151.
-------
PREFACE
This study was conducted by the U.S. Environmental
Protection Agency, under authority granted in the Federal
Water Pollution Control Act, as Amended (33 U.S.C. 466 et
seq.), 1970. Section 5 of the Act states that the Agency
can collect and report data relating to ". . .causes, con-
trol, and prevention of water pollution. ..."
The final report was prepared and written by Kathleen
G. Shimmin, Microbiologist, and Milton G. Tunzi, Biologist,
EPA, Region IX, Surveillance and Analysis Division, Labora-
tory Services Branch. Cooperation and assistance were re-
ceived from the following organizations during the conduct
of the study:
State of California, Department of Fish
and Game
State of California, Department of Health
State of California, San Francisco Bay
Regional Water Quality Control Board
State of California, Water Resources Control
Board
Johnson Oyster Company
11
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TABLE OF CONTENTS
Section
I Introduction
II Summary and Conclusions 2
III Bacteriological Assessment 3
Introduction ~
Methods £
Results and Discussion "
IV Chemical Assessment ^
Introduction IS
Methods 1^
Results and Discussion 16
V Biological Assessment 20
Introduction 20
Methods 20
Results and Discussion 20
VI Reference Material 23
Appendix A A-l
Appendix B B-l
Bibliography C-l
111
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LIST OF ILLUSTRATIONS
No. Page
-- m, *"*
1 Location of Shellfish Beds 4
2 Fecal Coliform Levels in Shellfish
Meats, By Station, April 7-23, 1972 8
3 Water Overlying Shellfish Beds, By 10
Station: Percent Which Exceeds
Standards, April - May, 1972
4 Median Total Coliform Numbers per
100 ml water samples, By Station,
April - May, 1972 12
IV
-------
LIST OF TABLES
No. Pag(
1 Identification Number and Description 5
of Shellfish Beds, Microbiological
and Chemical Assessments
2 Fecal Coliforms per 100 gm Shellfish 9
Meat: Range of Values and Comparison
to Standard, By Station
3 Total Coliforms in Water Overlying 11
Shellfish Beds: Median Values per 100
ml and Percent Exceeding 230 per 100
ml, By Station
4 Relationships Between Number of Viola- 14
tions in Shellfish Meat and Number
of Violations of the Two Water
Standards, By Station
5 Concentration of Selected Heavy Metals, 17
Wet Weight, By Station
6 Concentration, in PPB, of Selected 18
Chlorinated Hydrocarbons, By Station
7 Comparison of Clam Densities and Weight, 21
and "Angler" Days, in 19 Selected Beds,
1967 and 1972
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I. INTRODUCTION
From April to June 1972, a study was undertaken by the
Environmental Protection Agency, Region IX, to determine
whether or not selected San Francisco Bay shellfish beds
were contaminated and to determine whether or not signifi-
cant changes had occurred in the density and size of shell-
fish populations from 1967 to 1972. The beds surveyed were
those with commercial potential (as assessed by Wooster,
1968) and with dimensions greater than 10,000 square feet.
Laboratory analyses were conducted to determine the
existing health hazards as well as aesthetic quality of the
shellfish beds. Determinations were made to test the pres-
ence of selected heavy metals (lead, mercury, cadmium, cop-
per, chromium, zinc); pesticides, polychlorinated biphenyls
(PCBs); and bacteria of sanitary significance (total and
fecal coliforms, Salmonella). Results from San Francisco
Bay sampling stations were compared with data obtained from
analyses of commercial oysters grown at Drake's Estero.
-------
II. SUMMARY AND CONCLUSIONS
Summary
Selected San Francisco Bay shellfish beds and their
overlying waters were studied from April to June 1972. At
a number of locations, Bay shellfish were found to be con-
taminated by heavy metals and disease-causing bacteria,
rendering them unfit for human consumption. When 1967 and
1972 surveys were compared, a decline was noted in both
the shellfish mass and number of legal-sized clams.
Conclusions
1. Shellfish from San Francisco Bay had bacterial levels
which exceeded the standards set by the National Shellfish
Sanitation Program. From April to May 1972, there were 31
violations documented out of 48 total samples. Fourteen
out of a total of 16 beds were in violation at least once.
2. Salmonella organisms (disease-causing bacteria) were
isolated from two beds sampled: S_. kentucky was found at
Burlingame (Station 9), and S_. typhimurium at San Leandro
Bay (Station 20).
3. Waters overlying the shellfish beds also were in viola-
tion of bacterial standards set by the National Shellfish
Sanitation Program. During the period of study, the waters
overlying nine out of 16 beds exceeded the prescribed limits.
4. Chemical assessment of samples of shellfish meat showed
two stations to be in excess of Food and Drug Administration
(FDA) guidelines for lead in food. Two stations also exceeded
FDA guidelines for cadmium in food. Chlorinated hydrocarbons,
including polychlorinated biphenyls, were below the most re-
strictive FDA tolerance limits set for certain foods and ag-
ricultural products.
5. Between 1967 and 1972, there has been a decline of ap-
proximately 50 per cent in both the shellfish mass and number
of legal-sized clams found in 95 per cent of the shellfish
beds.
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III. BACTERIOLOGICAL ASSESSMENT
Introduction
Samples were collected from 16 shellfish beds and over-
lying waters in San Francisco Bay during the period of study
and analyses were performed to determine the levels of total
coliform (TC) , fecal coliform (FC) , and Salmonella. The re-
sults obtained were compared with those from the control bed,
a commercial source (Johnson's Oyster Company) which grows
oysters in Drake's Estero.
Figure 1 shows the location by numerical code of each
shellfish bed sampled in San Francisco Bay. An explanation
of the code appears in Table 1, while specific details on
the location of each site are given in Appendix A.
Methods
Water samples were collected at three points over each
shellfish bed. Sampling was repeated eight to 10 times for
each point. Shellfish samples were collected on 3 separate
days from each bed in the Bay. Three samples were collected
on one day from the control bed.
Analyses for total and fecal coliform bacteria were
performed in accordance with (1) Recommended Procedures for
the Examination of Sea Water and SKeTrfish,1970, and (2)
Standard Methods,1971. The most probable number (MPN) tech-
nique was employed, using five tubes per dilution.
Enrichments for Salmonella organisms were prepared
as follows. Ten grams of shellfish meat (suspended in buf-
fered dilution water and homogenized) was added to each of
six flasks, three containing Tetrathionate Broth (Difco),
and three containing Selenite Broth (Difco). A set of
broths was then incubated at each-of three temperatures:
37°, 41.5°, and 43°C. On 3 to 5 successive days, a sample
from the contents of each flask was streaked onto XLD
(Difco) and Brilliant Green (Difco) Agar plates. Colonies
with morphologies typical of Salmonellae were isolated in
pure culture, transferred to Brain Heart Infusion (BHI,
Difco) slants, gramstained, and screened for biochemical
reactions in Enterotubes (Roche Diagnostics). Biochemical
characters observed in the Enterotubes were: fermentation
of dextrose, dulcitol, and lactose; production of hydrogen
sulfide and indole, phenylalanine deaminase, urease, and
lysine decarboxylase; and citrate utilization. Isolates
giving physiological reactions typical of Salmonella re-
action patterns were screened for serological reacations
with Salmonella Vi and somatic group antisera (Difco).
-------
San
Rafael
San
Francisco
LOCATION OF SHELLFISH BEDS
MICROBIOLOGICAL
and
CHEMICAL ASSESSMENTS
San Fronclsco Boy, 1972
Figure 1
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TABLE I.--Identification Number and Description of Shellfish
Beds, Microbiological and Chemical Assessments,
San Francisco Bay, 1972.
Station
Numb e r
Description*
3
9
10
14
19
20
22
23
27
29
30
31
32
33
41
42
\
Control
Bayview Park
Burlingame
Coyote Point, north of
Foster City
Oakland Airport
San Leandro Bay
Alameda Memorial State Beach
Oakland Inner Harbor
Albany Hill
Point Richmond
Castro Point
Tara Hills, left
Tara Hills, middle
Tara Hills, right
Strawberry Point, west side
Richardson Bay, north end
Johnson Oyster Company, Drake's Estero
*Descriptions are adapted from Wooster (1968)
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Positive cultures were sent to the State of California,
Department of Health, for final typing and identification.
Initial screening for Salmonellae was performed by the
fluorescent antibody (FA) technique. Plates were prepared
(XLD and Brilliant Green Agars) from enrichment broths after
18 to 24 hours incubation. The inoculated plates were incu-
bated 2 to 3 hours, and colony smears were made on FA slides.
The slides were then stained with FA Salmonella Panvalent
Serum (Difco) and examined under a Leitz Fluorescence micro-
scope. Salmonella enrichment procedures were discontinued for
those samples giving less than 3+ fluorescence.
A chain of custody was maintained for each sample. The
data books show the sample tags and the names of sample col-
lectors and processors.
Samples were iced in transit. Water samples were pro-
cessed within 3 hours of collection, and shellfish within 4
hours. Temperatures of incubation were 35°± 0.5°C for total
coliforms and 44.5± 0.2°C for fecal coliforms. A recording
thermometer was used to monitor the covered circulating
water bath used for fecal coliform incubation.
The shellfish sampled were littleneck and soft shell
clams and oysters. Oysters were gathered only at Station
10 (Coyote Point) and at the Control Station. Clams were
gathered at all other stations. No attempt was made to
segregate the clam species.
Results and Discussion
Coliform values obtained during the study are sum-
marized in Figures 2-4, and Tables 2.4. Values for each
observation are found in Appendix B.
Bacterial standards for marketable shellfish (those
intended for shipment via interstate commerce) are set in
the National Shellfish Sanitation Program (1965). The State
of California, as a participant in the National Shellfish
Sanitation Program, also follows these standards. Limits
of the standard for shellfish meat are:
. . .fecal coliform density of not more
than 230 MPN per 100 grams. . ..
-------
For waters overlying the shellfish beds, the standard
states:
The coliform median MPN of the water does
not exceed 70 per 100 ml, and not more
than 10 per cent of the samples ordinarily
exceed an MPN of 230 per 100 ml for a 5-
tube decimal dilution test. . .in those
areas most probably exposed to fecal
contamination during the most unfavorable
hydrographic and pollution conditions. . ..
Figure 2 and Table 2 show the fecal coliform levels
found in shellfish at each station. As seen in Figure 2,
six stations out of the 16 total showed violation of the
standards 100 per cent of the time: Burlingame (9); Foster
City (14); Oakland Airport (19); Oakland Inner Harbor (23);
Albany Hill (27); and Strawberry Point (41). Five stations
showed violations two times out of three: Bayview (3); San
Leandro Bay (20) ; Point Richmond (29); Castro Point (30);
and Richardson Bay (42). Three stations showed one viola-
tion: Alameda (22); Tara Hills, left (31); and Tara Hills,
middle (32). Three stations had no violations during the
sample period: Coyote Point (10); Tara Hills, right (33);
and the Control.
As seen in Table 2, San Leandro Bay (20) and Richard-
son Bay (42) showed high values of 23,000 fecal coliforms
per 100 gm shellfish meat. This exceeds the standard (230
FC/100 gm) by a factor of 100 times. Salmonella organisms,
pathogenic bacteria, were isolated from two stations sam-
pled: Salmonella kentucky was found at Burlingame (9), and
S_. typhimurium at San Leandro Bay (20) . The lack of recov-
ery otsTiniTar" organisms from other beds, however, does not
automatically mean these beds were not contaminated, but
possibly that the recovery procedure did not succeed.
Figure 3 and Table 3 show the median total coliform
values in water overlying the shellfish beds. Violations of
standards (median equal to, or less than 70/100 ml) were
found at four stations: Oakland Airport (19); San Leandro
Bay (20); Castro Point (30); and Richardson Bay (42),
(Figure 3).
Figure 4 and Table 3 show the percent of water samples
exceeding the maximum allowable total coliform limit, (no
more than 10 percent of the samples shall exceed 230/100
ml). Violations of standards occurred at nine out of 16
stations: Burlingame (9); Coyote Point (10); Foster City (14);
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100.000
li
•*->-,'--J •.^•n-jt-Si i viiai VJ-:>;.1»> »~. K
-------
TABLE 2.--Fecal Coliforms per 100 gm Shellfish Meat: Range
of Values and Comparison to Standard, by Station.
Station
No.
3
9
10
14
19
20
22
23
27
29
30
31
32
33
41
42
Control
No. Times
Sampled
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
3
Fecal Coliforms
per 100 gm Range
230- 1,700
490- 4,900
50- 80
490- 2,300
1,100-17,000
170-23,000
<20- 330
490- 1,100
1,700-13,000
20- 1,400
110- 700
<20- 330
170- 1,700
20- 130
330- 3,300
<20-23,000
<2- 13
Sample Exceeds
230 FC per 100 em
No. Times
2
3
0
3
3
2
1
3
3
2
2
1
1
0
3
2
0
Percent
67
100*
0
100
100
67t
33
100
100
67
67
33
33
0
100
67
0
*Sa1mone11a kentucky isolated.
tSalmonella typhimuri urn isolated.
-------
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3 9 10 14 19 20 22 23 27 29 30 31 32 33 41 42
STATIONS
WATER OVERLAYING SHELLFISH BEDS.SF BAY,BY STATION:
PERCENT WHICH EXCEEDS STANDARDS, APRIL-MAY, 1972
Figure 3
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Table 3.--Total Coliforms in Water Overlying Shellfish Beds:
Median Values per 100 ml and Percent Exceeding 230
per 100 ml, by Station.
Station
No.
3
9
10
14
19
20
22
23
27
29
30
31
32
33
41
42
Control
No.
Observations
27
29
27
27
24
30
27
30
30
30
30
30
30
30
30
30
3
Total Coliforms
Median
per 100 ml
4
59
2
13
79
104
11
50
33
25
94
1
2
2
63
170
<2
Percent above
230 per 100 ml
7
21
11
15
29
40
0
17
0
13
37
0
0
0
10
40
0
11
-------
100
J
70
XX
IIIlJ
MAXIMUM ALLOWABLE LIMIT SET IN STANDARDS
o
o
UJ
0.
(T
O
U.
_J
o 10
L)
3 9 10 14 19 20 22 23 27 29 30 31 32 33 41 42
STATIONS
MEDIAN TOTAL COLIFORM NUMBERS PER IOOML
WATER SAMPLES BY STATION , SF BAY, APRI L - MAY, 1972
Figure 4
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Oakland Airport (19); San Leandro Bay (20); Oakland Inner
Harbor (23); Point Richmond (29); Castro Point (30); and
Richardson Bay (42). Four of these stations (19, 20, 30,
42) also exceeded the median total coliform limit per 100
ml (Figure 3).
Table 4 shows, by station, the correlation between
violations of the shellfish meat standard and violations
of the overlying water standards. Shelllfish meat from
14 out of 16 stations exceeded the bacterial standards at
least once. .
a) Four stations showed violations in all
three shellfish samples with a concomitant
violation of at least one water standard,
(upper limit of 230 TC/100 ml exceeded more
than 10 percent of the time). These stations
were: Burlingame (9); Foster City (14); Oak-
land Airport (19); Oakland Inner Harbor (23).
Oakland Airport (19) showed an additional
violation of the other water standard, (median
TC not to exceed 70/100 ml).
b) Three stations exceeded the shellfish meat
limit two times (out of three) with concomitant
violations of both water standards: San Leandro
Bay (20) ; Point Castro (30); and Richardson Bay
(42). One station, Point Richmond (29), had
violations in two shellfish meat samples and in
only one of the water standards (the percent
limit).
c) Three stations exceeded the shellfish meat
limit one time, with no violations of either
water standard: Alameda (22); Tara Hills, left
(31); and Tara Hills, middle (32).
d) One station showed violation of one water
standard (the percent limit) but no violation
of shellfish meat limits: Coyote Point (10).
e) One station, Tara Hills, right (33), and
the Control showed no violations for shellfish
meat or for overlying water standards.
13
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TABLE 4.--Relationships Between Number of Violations in
Shellfish Meat and Number of Violations of the
Two Water Standards, By Station.
No. Times Shellfish Meat Exceeded Standards
Three Times
Sta 9*
14*
19*t
23*
27
41
Two Times
Sta 3
20*t
29*
30*t
42*t
One Time
Sta 22
31
32
No Time
Sta 10*
33
Control
*Concomitant violation of Water Standard "not more than
10% of samples exceed 230 total col 1 form/100 ml".
tconcomitant violation of Water Standard "median total
coliform not to exceed 70/100 ml".
14
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IV. CHEMICAL ASSESSMENT
Introduction
Although the National Shellfish Sanitation Program
currently has no standards set for concentrations of heavy
metals or chlorinated hydrocarbons in shellfish meat, stan-
dards for some parameters have been set by the Food and
Drug Administration for certain foods. Tests were conducted
to determine the existing level of heavy metals found in
San Francisco Bay shellfish, and to compare these levels
with existing food standards. Chemical assessments were
performed to determine concentrations of: cadmium, chromium,
copper, lead, mercury, zinc, and chlorinated hydrocarbons.
Methods
Samples undergoing analyses for heavy metals were
subjected first to wet digestion and then to analyses by
atomic absorption spectrophotometry, using the Perkin-
Elmer 403. Spectrophotometry was in accordance with EPA
procedures (1971).
For wet digestion, the following procedures were
followed. A weighed sample was suspended in a solution of
10 ml redistilled, concentrated nitric acid plus 1 ml hydro-
gen peroxide. Digestion proceeded in a sand bath at 60°C
until tissue dissolved; the temperature was then gradually
increased to 95° C. The volume was evaporated to 2 - 3 ml.
One ml distilled, concentrated hydrochloric acid was added
and digestion continued for 15 minutes at 95°C. The contents
were cooled slightly and quantitatively transferred with warm
(50°C) 1 percent nitric acid into a 25 ml volumetric flask.
After cooling, the digested material was brought up to vol-
ume with an additional 1 percent nitric acid. There was no
filtration step. The material was then ready for analysis.
To insure quality control, precision (duplicates) and
accuracy (spikes) checks were performed. About 25 percent
of the samples were spiked with known amounts of selected
heavy metals. Recovery (or accuracy) ranges were: cadmium,
88.8-101 percent; chromium, 93.0-106 percent; copper, 96.4-
102 percent; lead, 88.7-104 percent; mercury, 65-106.5
percent, (the three values in the range were 65, 99.2 and
106.5 percents, with 65 percent recovery occurring in a
very low level spike of the control sample); and zinc,
95.0-99.8 percent.
Chlorinated hydrocarbons were determined by gas chro-
matographic procedures (EPA, 1971). The following steps
15
-------
were used: hexane/isopropanol extraction; hexane/acetoni-
trile liquid-liquid partition; Florisil fractionation; and
identification and quantitation by both multicolumn electron
capture and microcoulimetric gas chromatography, using a
Microtek MT-220.
Results and Discussion
Table 5 shows the wet weight levels of selected heavy
metals for each shellfish bed. The following ranges (in PPM,
or mg/kg) were observed in samples of shellfish meat from
the 16 stations and the Control: cadmium, 0.06-1.41; chro-
mium, 0.10-6.65; copper, 1.12-48.2; lead, 0.23-18.7; mercury,
0.01-0.15; and zinc, 8.48-157. These values generally fall
within the ranges observed by Pringle, Hissong, Katz and
Mulawka (1968) in selected clams and oysters found on the
East and West Coasts of the United States. However, the lead
levels reported at Bayview (3), 10.5 PPM, and at Albany Hill
(27), 18.7 PPM, exceeded the upper limit reported by Pringle,
et al. , of 10.2 PPM in softshell clams.
The Food and Drug Administration has established tol-
erance guidelines for certain heavy metals in a variety of
foods. The recommended tolerance limit for lead in food is
7 PPM. Again, this level was exceeded at two stations: Bay-
view (3), 10.5 PPM, and Albany Hill (27), 18.7 PPM.
The FDA recommended guideline for cadmium in food is
0.5 PPM. According to Nilsson (Metals and Ecology, 1969),
cadmium accumulated by humans is almost never excreted and
can cause both acute and chronic poisonings. Shellfish
meat from two stations exceeded guidelines for cadmium;
Oakland Inner Harbor (23) had a cadmium value of 0.58 PPM,
and Coyote Point (10), 1.41 PPM. All of the other shellfish
beds had cadmium levels below 0.5 PPM.
The FDA recommended guideline for mercury in food is
0.5 PPM. All values observed during the study fell below
this limit.
There is no established guideline for zinc. During
the study, values observed in clams ranged from 8.48-35.1
PPM. For oysters, higher levels were observed: Control,
57.6 PPM; and Coyote Point (10), 157 PPM. Pringle, et al.
(1968) state that oysters tend to concentrate zinc, so
that a range of 800-1000 PPM zinc would be considered normal.
Table 6 lists the concentration of selected chlori-
nated hydrocarbons (wet weight) by shellfish bed. Included
are pesticides (dieldrin and metabolites of DDT) and PCB's
(Arochlor 1242, 1254).
16
-------
TABLE 5.--Concentration of Selected Heavy Metals, Wet Weight, By Station
EPA Lab
Numb e r
16SF042
5SF042
1SSF042
6SF042
7SF042
8SF042
14SF042
13SF042
28SF042
36SF042
35SF042
29SF042
30SF042
31SF042
33SF042
32SF042
Control
Coll.
Date
4/7/72
4/7/72
4/7/72
4/7/72
4/7/72
4/7/72
4/8/72
4/7/72
4/8/72
4/8/72
4/8/72
4/8/72
4/8/72
4/8/72
4/8/72
4/8/72
5/23/72
Sample
Description
#3/Bayview
#9 Burlingame
#10 Coyote Pt.-N
#14 Foster City
#19 Oakland Airport
#20 San Leandro Bay
#22 Alameda Mem.
State Park
#23 Oakland Inner
Harbor
#27 Albany Hills
#29 Pt. Richmond
#30 Castro Pt.
#31 Tara Hills (L)
#32 Tara Hills (M)
#33 Tara Hills (R)
#41 Strawberry Pt.-W
#42 Richardson Bay
Johnson Oyster Co.
Drake's Estero
Concentration, Wet Weight in mg/Kg
Cadmium
0.21
0.15
1.41
0.12
0.13
0.33
0.35
0.58
0.21
0.25
0.06
0.14
0.09
0.06
0.29
0.16
0.33
Chromium
2.62
0. 88
0.79
0.30
0.53
0.56
1.17
0.67
3,64
0.31
0.84
1.70
6.65
3.99
1.47
2.96
0.10
Copper
5.73
1.20
48.19
1.38
1.12
1.34
1.98
1.21
6.60
1.94
1.25
2.47
4.66
2.62
4.05
3.52
2.03
Lead
10.53
1.32
1.75
0.41
0.42
1.22
0.93
3.82
18.70
0.71
0.23
1.53
1.84
2.17
1.79
2.92
0.93
Mercury
0.03
0.01
0.15
0.03
0.02
0.02
0.05
0.06
0.06
0.09
0.03
0.04
0.09
0.05
0.06
0.06
0.04
Zinc
18. 71
8.48
156.63
10.47
9.30
10.62
24.03
35.05
24.53
20.25
9.11
17.41
14.93
14.60
19.32
18.27
57.57
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TABLE 6.--Concentration, in PPB, of Selected Chlorinated Hydrocarbons by Station,
San Francisco Bay Study, April - May 1972
».
Chlorinated
Hydrocarbon
Arochlor
1242, 1254
Dieldrin
pp' DDE
op' DDE
op' ODD
op1 DDT
pp' ODD
pp' DDT
Unknown
STATION *
3
26.5
-§
4.2
1.3
-
1.2
1.1
2.3
-
9
10.5
0.9
7.2
4.4
tr t
3.6
3.6
4.8
10
446.
2.8
28.0
13.0
-
22.0
7.0
24.0
-
14
23.8
0.9
1.9
0.8
-
0.8
0.5
1.1
-
19
91.0
1.2
4.3
2.0
-
2.3
1. 7
3.0
-
20
75.0
1.0
5.5
3. 5
-
8.0
2.5
3.5
-
22
64.7
1.0
5.8
2.9
-
2.4
1.4
2.4
-
23
119.
0.4
4.0
2.1
-
1.0
2.0
2.0
-
27
88.0
4.0
7.2
2.0
1.2
1.6
2.8
3.6
-
29
252.0
-
1.6
1.2
tr
0.4
1.2
1.0
-
30
25.9
-
1.4
1.3
tr
0.5
1.2
1.2
-
31
25.4
1.0
2.2
0.8
tr
0.4
1.2
0.6
-
32
37. 8
1. 2
7.0
1.7
-
-
1.7
0.8
-
33
39.4
0.8
3.4
2.0
tr
1.2
2.2
1.6
-
41
18.0
-
2.2
2.0
-
0.9
0.9
0.3
-
42
29.1
0.6
1.8
1.9
tr
0.7
0.7
1.3
-
cit
4.7
-
1.2
2.6
-
1.8
1.2
-
1.8
c2t
3.8
-
tr
2.1
-
1.3
0.6
-
2.2
*For Station location, see Table 1 and Figure 1,
Dates of Collection:
7 April, 1972
8 April, 1972
17 April, 1972
18 April, 1972
20 April, 1972
23 May, 1972
#3, 9, 10, 14, 20, 22, 31
#23, 29, 30, 32, 33
#19
#41, 42
#27
Cl, C2
t C] and C2 are reference samples for Johnson
Oyster Co.
* tr = trace amount (less than 1.0 ppb).
§ - means none detectable.
-------
Concentrations of chlorinated hydrocarbons found in
shellfish were below the most restrictive FDA guidelines
for food. According to FDA guidelines, tolerance limits
for PCB's vary depending upon the kind of food contami-
nated. For example, values above 0.5 PPM in eggs, 5.0
PPM in fish, and 5.0 PPM in chicken, are all considered
potentially hazardous.* The highest level observed during
the Bay study was 0.446 PPM at Coyote Point (10), a level
still below the most restrictive tolerance limit.
Recent studies (Duke, Lowe, Wilson, 1970) have in-
dicated that under test conditions low levels of PCB's
(1.0 PPB) can inhibit shell development in oysters.
Whether or not this effect has occurred at Coyote Point
(10), was not determined by this study.
Tolerance limits for DDT and its metabolites are set
at 7 PPM for certain agricultural products and at 0.05 PPM
for milk. Values for all the shellfish meat tested were
below 0.05 PPM.
*Eggs have the lowest tolerance limits because they are
consumed in quantity by infants.
19
-------
V. BIOLOGICAL ASSESSMENT
IntrojiuctJLon
Samples of clams were collected from 19 shellfish
beds in San Francisco Bay in order to appraise the
changes in clam density and size which have occurred be-
tween 1967 and 1972. The 1967 data used was collected by
Wooster (1968). The species of clams compared were those
most commonly encountered by the Bay sportsman: Mya arenaria
(softshell clam) and Tapes semidecussata (Japanese little
neck).
Methods
Nineteen of the 42 shellfish beds previously surveyed
by Wooster were sampled for species composition and density,
following his prescribed methods. This involved taking a
square foot of substrate to a depth that would include all
available shellfish, and placing the material in a wooden-
frame sampler with a 1/4-inch hardware cloth bottom. By
shaking the sampler in water, the sand, mud and small
gravel were removed, retaining larger material along with
any clams. The shellfish from each square foot of sample
were then placed in a plastic bag and taken to the labora-
tory. Each shellfish was measured for size, and all shell-
fish of the same species were combined to obtain a total
weight for each sample.
"Angler" days were calculated by dividing the number
of legal-sized clams found in the bed by 50, the daily al-
lowable limit.
Results and Discussion
A summary of the results of the clam survey is given
in Table 7. It shows the average weight in grams per square
foot, total weight of clams in kilograms, and total "angler"
days recorded for the 19 shellfish beds during both the
1967 and 1972 surveys. The results are based on 105 samples
taken in 1967 and 125 samples in 1972. They show a decline
in shellfish mass and number of legal-sized clams over the
5 year period: a loss of 83 grams average weight per square
foot of shellfish bed area; a loss of 330,400 kilograms
total weight; and a loss of 210,300 "Angler" days. The
magnitude of the decline has been a 42 percent loss in mean
grams of clam weight per square foot of shellfish bed area,
50 percent loss in legal-sized clams, and 53 percent loss in
total weight of clams in kilograms. A more extensive analy-
sis of this data is on file at the EPA, Region IX, Surveil-
lance and Analysis Division.
20
-------
TABLE 7.--Comparison of Clam Densities and Weight, and "Angler" Days, in 19 Selected
Beds, 1967 and 1972.
Date
1967
1972
No. of Samples
105
125
Absolute Loss
Percentage Decrease
Avg. Wt.
gm/ft2*
196
113
83
42%
Total Wt.
Kgt
618000
287600
330400
53%
Total
"Angler" Days5
418900
208600
210300
50%
* Average weight of clams, in grams, per square foot of shellfish bed area.
t Total estimated weight, in kilograms, of all clams in the 19 shellfish
beds sampled.
5 "Angler" days is the legal limit for sportsmen, 50 clams, 38mm in length.
-------
The 19 beds surveyed for clam density and biomass
comprise 95 percent of the total area listed and sampled
by Wooster (42 beds], who attempted to survey all existing
shellfish beds in the Bay. It is improbable, however, that
Wooster was able to sample all clam beds in the periphery
of San Francisco Bay since some are inaccessible and re-
main underwater even at low tide.
22
-------
VI. REFERENCE MATERIAL
23
-------
APPENDIX A
STATION LOCATIONS
A-l
-------
SHELLFISH BED LOCATIONS
#5/Bay View Park
Driving north on Bayshore (U.S. 101), take "Candle-
stick Park" turnoff. Pull off road at culvert outflow.
Bed location begins here and runs north.
#9/Burlingame
Proceed north on Bayshore (U.S. 101). About 0.5
miles beyond Coyote Point, on right side of road is an
enclosed lagoon. Bed is situated in this lagoon.
#10/Coyote Point, North of
Take East Peninsula Avenue into Coyote Point Park.
Turn left at Castaway and drive into parking lot. Proceed
to end of lot, facing toward the freeway. Bed is situated
along the entire beach, approximately one mile.
#14/Foster City
After crossing San Mateo Bridge (driving southwest),
take first road to the right. Circle back and park on
right of bridge. Walk under bridge. Bed extends in a
large area from remnants of the old San Mateo Bridge, south,
#19/0akland Airport
Follow Oakland Airport Drive. Turn left at first
Standard Oil Service Station and right at first dirt road.
Bed is situated along inlet to the west.
#20/San Leandro
In Alameda, follow Otis Drive and proceed toward
Oakland Airport. After crossing bridge to Bay Farm Island,
the road becomes Doolittle Drive. Continue to a point where
the water (San Leandro Bay) ends on the left, (wire fence
will also end). Bed stretches from corner of fence, back
about 100 yards.
#22/Alameda Memorial State Park
In Alameda, turn from Central Avenue onto McKay Street
(Federal Center) and proceed to road's end. Bed is situated
around point of land, starting on the beach section, even
with end of McKay Street.
A-2
-------
^23/Oakland Inner Harbor, at foot^ of Alice St.
Prom Alameda, drive north on Webster Street through
Posey Tube and turn right onto Seventh Street. Turn right
at Jackson and drive under freeway (I1WY 17). Turn right on
Fourth Street to Alice Street, and left on Alice to end of
street. Bed is located partially under old piers, which
extend about 100 yards to the left (of Alice Street).
/*27/Albany Hill
Proceed north on State HWY 17/Interstate 80. Take
"HWY 17" turn-off toward Richmond (Hoffman Boulevard).
Bed is located between Central Avenue and Golden Gate Fields.
#29/Point Richmond
Proceed north and northwest on State HWY 17 toward
Richmond-San Rafael Bridge. Take Garrard Boulevard left
(toward Richmond Plunge) and go through the tunnel. Park
along side of road at Keller Cove Park. Bed is located
along entire cove, from Ferry Point to Cypress Point.
#30/Castro Point, et al.
Proceeding northwest on State HWY 17, take "Pt.
Molate" turnoff. Drive past U.S. Government Guard Station
and continue to end of road. Beds are located in several
coves. The station location includes Castro Point, Point
Molate, Point Orient, and Point San Pablo.
#51, 52, 55/Tara Hills
Follow San Pablo Avenue to Tara Hills Boulevard in
Pinole. Turn left. Immediately turn onto small road lead-
ing to San Pablo Waste Water Treatment Plant. Walk over
railroad track (near small creek). Bed #32 is delineated
by an old fence. Beds #31 and #33 are south and north
of #32.
#41/Strawberry Point
Proceed north on U.S. 101. Take Strawberry Point Road
(Seminary Drive) and follow until approaching near water.
Clam beds are located at bend and in cove. At east end of
bed, posts are visible in the water. An access path is
located at this east end.
#42/Richardson Bay
Bed is located under north end of U.S. 101 bridge which
spans Richardson Bay. Bed extends eastward from the bridge
piers.
A-3
-------
WATER STATIONS
Sta 5 - Bay View (boat) - inlet
A. Opposite piling. Brown building, left edge, lines up
with apartment building, left edge.
B. Opposite storm drain.
C. Opposite water tank - "C" in Cow Palace sign and tele-
phone pole line up.
Sta 9 - Burlingame (foot) - water's edge
A. Pile of rocks opposite grove of eucalyptus.
B. Between three towers and eucalyptus.
C. Storm drain.
Sta 10 - Coyote Point North (boat)
Line-Coyote Point and white billboard
A. (Rt.) Three tower poles line up - line up with Pirelli
Tire Building.
B. (Middle) Opposite group of four cement piers, three tower
poles line up.
C. (Left) Three tower poles line up.
Sta 14 - Foster City (boat)
Line-bridge facing south sixth pier
A. Line up power line piers (second framed by first).
B. Two telephone poles line up.
C. Power towers line up.
Sta 19 - Oakland Airport (boat)
Line-end of pier and tower
A. Stack on shack lines up with ball dome on hill.
B. Yellow marker lines up with clump of trees (above dump).
C. Left corner of flat yellow roof is at right edge of
right gray cover above pumps.
A-4
-------
Sta 20 - San Leandro Bay (foot) - water's edge
A. End of pier.
B. Line up with fence.
C. Point of land by sand blast; line up telephone pole
nest to billboard with power pole behind (on green building)
Sta 22 - Alameda Memorial State Beach (foot) -water's edge
Shell fish from cove
A. West point.
B. Center of cove.
C. East point.
Sta 23 - Oakland Inner Harbor (foot) - water's edge
A. Last elevated piling (line up with edge of brick
building).
B. Line up with first fallen log from fence and sign
"Slow" across estuary.
C. Foot of Alice Street marker.
Sta 27 - Albany Hill (boat)
Line-point of land beyond towers
A. Two telephone poles line up beige building between.
B. Campanile (U.C. Berkeley campus) lines up with duck
blind.
C. Right side duck blind lines up with right side of pink
house on hill.
Sta 29 - Point Richmond (foot) - water's edge
A. By casing.
B. Point with riprap.
C. Rocky point; spire on Golden Gate Bridge is centered
between two hills.
A-5
-------
Sta 50 - Castro Point, et al. (foot) - water's edge
A. Edge of piling.
B. Middle of bed-walls.
C. Point of land extending.
LINE FOR STA 31, 52, 53 - tall smoke stack ahead, clump
of trees on pointi
Sta 31 - Tara Hills (boat)
A. On turquoise building, the center vent lines up with
telephone pole.
B. Pink tanks on hill line up.
C. In second row, white houses line up.
Sta 52 - Tara Hills (boat)
A. Black pole lines up with right edge of first projection
on red roof.
B. Middle tower on hill lines up with right edge of
red roof.
C. Middle tower and left edge of red roof line up.
Sta 55 - Tara Hills (boat)
A. Water tower lines up with "V" in hills (right).
B. White sign lines up with right edge green house.
C. Back pink tank, right edge, lines up with left edge
of front pink tank.
Sta 41 - Strawberry Point (foot) - water's edge
A. Water's edge by large boulder on beach.
B. Opposite acacia tree.
C. Left pole in water lines up with right tank on fill;
station is opposite pipe in road.
A-6
-------
Sta 42 - Richardson's Bay (foot) - water's edge
A. Point of land toward marker.
B. Center of bed.
C. Piers for bridge (3rd from left).
A-7
-------
APPENDIX B
BACTERIOLOGICAL DATA
B-l
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Shellfish
FECAL COLIFORM, MPN/100 gm
Shellfish Bed
Location and Number
DATE SAMPLED
4/7-8/72 4/17-18/72 4/22-23/72 5/23/72
Bayview (3)
Burlingame (9)
Coyote Point (10)
Foster City (14)
Oakland Airport (19)
San Leandro Bay (20)
Alameda (22)
Oakland Inner Harbor
Albany Hills (27)
Pt. Richmond (29)
Pt. Castro (30)
Tara Hills No.
Tara Hills No.
Tara Hills No.
Strawberry Pt.
Richardson Bay
Johnson Oyster
Drake's Estero
Station
Station
Station
(23)
13
1 (31)
2 (32)
3 (33)
(41)
(42)
Co. ,
-- Control
A
B
C
230
490
50
,300
,100
,300
50
490
,000
490
330
20
170
70
330
<20
330
1,300
80
790
17,000
170
330
1,100
1,700
20
700
330
230
130
330
23,000
1,700
4,900
80
490
2,200
23,000
<20
1,100
7,000
1,400
110
<20
1,700
20
3,300
1,700
2
13
<2
Source: EPA Laboratory, Region IX
B-2
-------
SAN FRANCISCO BAY SliELLFISH STUDY
Bacteriological Tests of Overlvina Waters
Shellfish Bed Location
and Number: Bay view (3)
COLIPORM, KPN/100 ML
Date
Sampled
4/19/72
4/21/72
4/25/72
4/26/72
4/27/72
4/28/72
5/1/72
5/2/72
5/3/72
STAr
Total ,
Confirmed
2
<2
5
<2
350
^2
no
<2
<2
ION A
Fecal
<2
<2
5
<2
no
<2
49
<2
<2
ST.-.1
Total , i
Confirmee
5
<5
33
<2
2400
2
79
5
4
:ICN B
Fecal
<2
<2
4
<2
490
<2
23
2
4
STA:
Total,
Confirr.2d
<2
4
350
<2
130
2
240
5
2
ION C
Fecal
<2
<2
130
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Burlingame (9)
COLTPORM, MPN/100 ML
Date
Sampled
4/19/72
4/21/72
4/25/72
4/26/72
4/27/72
4/28/72
5/1/72
5/2/72
5/3/72
5/4/72
STAr
Total,
Confirmed
49
<4
49
8
2
13
220
460
70
79
ION A
Fecal
8
<2
8
2
<2
2
23
90
2
2
STA1
Total, 1
Confirmee
17
17
21
33
2
no
noo
22
330
240
TON B
Fecal
4
17
8
5
2
13
49
8
22
<2
STA:
Total,
Confirmed
14
130
110
17
220
49
920
92,000
33
ION C
Fecal
8
17
4
17
49
<2
350
490
5
Remarks
i
Source: EPA Laboratory, Region IX
B-4
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlvir.er Waters
Shellfish Bed Location
and Number: Coyote Pt. (10)
COLIFORM, 3-2PN/100 ML
Date
Sampled
4/19/72
4/21/72
4/25/72
4/26/72
4/27/72
5/1/72
5/2/72
5/3/72
5/10/72
STA:
Total,
Confirmed
490
<'2
<2
<2
<2
14
2
2
5
ION A
Fecal
2
<2
<2
<2
<2
<2
<2
<2
<2
STM
Total, 1
Confirmee
1700
2
2
<2
^2
<2
2
7
2
?ION B
Fecal
13
<2
<2
<2
<2
<2
<2
2
\t
SIK
Total,
Confirmed
1100
<2
<2
<2
^2
2
11
^2
<2
ION C
Fecal
13
<2
<2
^2
^2
V2
2
^2
<"2
*
Remarks
Source: EPA Laboratory, Region IX
B-5
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Foster City (14)
COLIFORM, MPN/100 ML
Date
Sampled
4/19/72
4/21/72
A/25/72
4/26/72
A/27/72
5/1/72
5/2/72
5/3/72
5/10/72
STA'
Total,
Confirmed
330
2
540
8
<2
8
17
4
13
ION A '
Fecal
130
2
540
<2
<2
2
17
4
13
STATION B
Total, 1
Confirmeq Fecal
330
22
49
33
2
33
23
2
8
230
7
49
8
<2
17
13
2
<2
STA*:
Total,
Confirmed
790
130
13
2
13
13
11
7
<2
ION C
Fecal
790
49
13
<2
2
13
11
2
<2
Rerarks
Source: EPA Laboratory, Region IX
B-6
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Oakland Airport (19)
COLIFORM, MPN/100 ML
Date
Sampled
4/19/72
4/21/72
4/27/72
5/1/72
5/2/72
5/3/72
5/10/72
5/11/72
STAT
Total,
Confirmed
79
79
8
49
170
3300
170
49
ION A
Fecal
7
49
8
5
70
2300
79
5
nnroN B
Fecal
79
79
49
13
4900
3300
790
17
8
170
17
'
700
1300
170
5
STATION C
Ibtal,
Confirmed Fecal
350
130
13
49
4600
1100
4900
22
27
33
5
2
1600
460
1300
5
Remarks
Source: EPA Laboratory, Region IX
B-7
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Be
and
Date
Sampled
4/19/72
d Location
Number:
STAT
Total,
Confirmed
4
4/21/72 <2
4/25/72
4/26/72
4/27/72
5/1/72
5/2/72
5/3/72
5/4/72
5/10/72
17
49
17
33
2300
5
>240,000
35,000
San Leandro Bay (20)
ION A
Fecal
<2
<2
8
11
11
4
490
<2
92,000
5400
COUFOBM, MPN/.
STATION B
Total, 1
Confirmed Fecal (
n
2
130
2300
14
2
4600
79
92,000
24,000
2
<2
8
790
9
<2
490
8
11,000
7900
LOO ML
STAT:
total,
Ztonfirmed
31
330
130
1700
130
7
4900
33
>240,000
3500
row c ||
Fecal Remarks
31
330
7
330 :
33
<2
460
2
35,000
4900
Source: EPA Laboratory, Region IX
B-8
-------
SAN FRANCISCO BAY SHKT.T.FISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Alameda (22)
COLIFORM, MPN/100 ML
Date
Sampled
4/19/72
4/26/72
4/27/72
4/28/72
5/1/72
5/2/72
5/3/72
5/4/72
5/9/72
STA!
Total,
Confirmed
<2
17
8
33
5
5
<2
5
2
TON A
Fecal
<2
5
5
33
2
5
<2
5
2
STA3
Total, 1
Confirmee
4
22
13
79
5
11
17
23
5
?ION B
Fecal
2
11
13
79
2
7
' 4
8
5
STAJ
Total,
Confirmed
11
23
2
27
2
2
5
13
23
ION C
Fecal
7
13
2
27
2
2
<2
8
8
Remarks
Source: EPA Laboratory, Region IX
B-9
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Oakland Inner Harbor (23)
COLIFORM, MPN/100 ML
Date
Sampled
4/19/72
4/25/72
4/26/72
4/27/72
5/1/72
5/2/72
5/3/72
5/4/72
5/8/72
5/9/72
STATION A
Total,
Confirmed] Fecal
230
49
79
240
49
49
22
49
5
22
22
13
79
240
13
4
2
8
<2
22
STA1
Total, 1
Confirmee
49
79
170
130
22
5
17
350
11
13
TON B
Fecal
11
8
no
22
22
<2
8
70
4
8
STAT
Total,
Confirmed
49
79
240
33
350
240
27
no
13
49
ION C
Fecal
17
23
13
13
130
22
17
79
2
33
Remarks
Source: EPA Laboratory, Region IX
B-10
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlvino Waters
Shellfish Bed Location
and Number: Albany Hill (27)
COLIPOPM, MPN/100 ML
Date
Sampled
4/10/72
4/14/72
4/16/72
5/8/72
5/9/72
5/11/72
5/12/72
5/17/72
5/18/72
5/22/72
STA'
Total,
Confirmed
130
5
33
33
130
33
5
5
130
14
TON A
Fecal
22
<2
4
8
130
13
5
<2
5
4
STA'
Total,
Confirmee
no
13
70
5
230
79
7
5
79
8
[TON B
Fecal
5
8
<2
5
230
11
4
<2
13
5
STA'
Total,
Confirmed
130
70
70
14
170
2
2
17
49
23
ION C
Fecal
11
n
8
2
170
<2
2
2
7
8
Remarks
•
Source: EPA Laboratory, Region IX
B-ll
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Pt. Richmond (29)
COLIFORM, MPN/100 ML
Date
Sampled
4/10/72
4/11/72
4/12/72
4/13/72
4/14/72
5/5/72
5/8/72
5/11/72
5/12/72
5/15/72
STAr
Total,
Confirmed
2
14
5
79
17
23
13
79
<2
46
TON A
Fecal
2
2
<2
13
8
2
5
49
<2
46
STA1
Total, 1
Confirmee
<2
33
no
170
790
5
2
^2
310
no
?ION B
Fecal
<2
49
23
130
330
<2
2
<2
170
70
STAT
Total,
Confirmed
2
49
790
17
8
490
8
2
33
70
ION C
Fecal
2
23
130
2
2
8
5
<2
14
49
Remarks
Source: EPA Laboratory, Region IX
B-12
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Nurrtoer: Pt. Castro (30)
COLIFORM, MPN/100 ML
Date
Sampled
4/10/72
4/11/72
4/12/72
4/13/72
4/14/72
5/5/72
5/8/72
5/11/72
5/12/72
5/15/72
STAf
Total,
Confirmed
140
49
700
170
330
16,000
1300
79
240
540
ION A I STAT
Total, I
Fecal 1 Confirmee
70
9
230
5
11
9200
330
49
27
70
31
22
130
|— —
140
230
24,000
700
11
49
350
TON B
'
Fecal ji
'
,
49
14
33
16,000
700
5
49
79
STK
Ibtal,
Confirmed
33
49
220
79
130
3500
49
23
79
"°
ION C
Fecal
5
5
Remarks
11
8
17
3500
49
8
49
49
Source: EPA Laboratory, Region IX
B-13
-------
SAN FPANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Tar* Hills No. 1 (31)
COLIFORM, MPN/100 ML
Date
Sampled
4/10/72
4/14/72
4/16/72
5/8/72
5/9/72
5/11/72
5/12/72
5/17/72
5/18/72
5/22/72
ST#
Total,
Confirmed
2
5
5
2
<2
2
<2
5
<2
2
TON A
Fecal
2
2
<2
<2
<2
<,2
<2
2
<2
2
STATION B
Total, 1
Confirmed Fecal
<2
8
5
C2
<2
<2
<2
<2
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Tara Hills No. 2
COLIFORM, MPN/100 ML
Date
Sampled
4/10/72
4/14/72
4/16/72
5/8/72
5/9/72
5/11/72
5/12/72
5/17/72
5/18/72
5/22/72
STAr
Total,
Confirmed
2
<2
8
70
5
<2
8
2
<2
<2
ION A
Fecal
<2
<2
5
<2
C2
<2
2
<2
<2
^2
STATION B
Total, 1
Confirmee} Fecal
5
2
13
5
<2
<2
<2
23
<2
2
5
<2
8
V
<2
<2
<2
2
^2
2
STA'
Total,
Confirmed
2
14
14
<2
2
<2
<2
<2
<2
4
ION C
Fecal
^2
14
5
<2
<2
<2
<2
^2
<2
2
Remarks
i
Source: EPA Laboratory, Region IX
B-15
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Tara Hills No. 3 (33)
COLIFORM, MPN/100 ML
Date
..-•'iinled
4/10/72
4/14/72
4/16/72
5/8/72
5/9/72
5/11/72
5/12/72
5/17/72
5/18/72
5/22/72
STA:
Total,
Confirmed
2
7
<2
<2
<2
2
2
5
170
5
'ION A
Fecal
<2
2
<2
<2
<2
<2
<2
<2
13
2
STA1]
Total, 1
Confirmee
2
4
<2
<2
<2
<2
<2
2
490
2
t
[•ION B
Fecal
<2
2
<2
<2
<2
<2
<2
<2
8
«•>
STAr
Total,
Confirmed
<2
2
2
<2
<2
<2
2
2
n
<2
ION C
Fecal
<2
2
<2
<2
<2
<2
<2
2
<2
<2
Remarks
Source: EPA Laboratory, Region IX
B-16
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Strawberry Pt. (41)
COKEFORM, MPN/100 ML
Date
Sampled
'4/10/72
4/11/72
4/12/72
4/13/72
4/14/72
5/8/72
5/9/72
>
5/11/72
5/12/72
5/15/72
sriK
Total,
Confirmed
5
180
170
130
17
33
13
230
46
<2
ION A
Fecal
2
49
170
49
2
7
<2
8
23
<2
STAl
Total, 1
Confirmee
7
230
130
79
7
17
540
180
46
7
?ION B
Fecal
7
79
49
79
7
2
230
33
46
7
STA'
Total,
Confirmed
8
330
130
170
49
49
540
49
79
180
ION C
Fecal
5
79
27
23
13
11
170
23
27
180
Remarks
Station A
Sampled on
5/17/72
Source: EPA Laboratory, Region IX
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Richardson Bay (42)
COLIPORM, MPN/100 ML
Date
Sampled
4/10/72
4/11/72
4/12/72
4/13/72
4/14/72
5/8/72
5/9/72
5/11/72
5/12/72
5/15/72
STAr
Total,
Confirmed
no
1300
2300
700
49
22
790
170
220
79
TEON A
Fecal
17
330
330
94
22
5
170
22
140
79
STATION B
Total, 1
Confirmed Fecal
3500
1300
130
180
23
130
790
33
110
920
40
94
130
140
23
33
490
23
22
350
STA1:
Total,
Confirmed
1400
230
490
170
8
130
790
49
49
170
TON C
Fecal
130
no
79
5
22
26
33
8
79
Remarks
Source: EPA Laboratory, Region IX B-18
-------
SAN FRANCISCO BAY SHELLFISH STUDY
Bacteriological Tests of Overlying Waters
Shellfish Bed Location
and Number: Johnson Oyster Co., Drakes Estero - CONTROL
Date
Sampled
5/23/72
STA'
Total,
Confirmed
5
COLIFORM, MPN/
TON A I STATION B
Total, 1
Fecal l| Confirmeq Fecal
5
<2
<2
100 ML
STAT
Total,
Confirmed
<2
ION C
Fecal
•C2
Remarks
Source: EPA Laboratory, Region IX
B-19
-------
BIBLIOGRAPHY
1. American Public Health Association, 1970. Recommended
Procedures for the Examination of Sea Water and Shell-
fish. Fourth Edition. APHA, Inc. New York, New York
10019.
2. American Public Health Association, 1971. Standard
Methods for the Examination of Water and Wastewater.
Thirteenth Edition. APHA, Inc. New York, New York 10019.
3. Duke, T.W., J.I. Lowe, and A.J. Wilson, 1970. "A Poly-
chlorinated Biphenyl (Arochlor 1254) in the Water, Sed-
iment, and Biota of Escambia Bay, Florida". Bull. Env.
Contam. $ Toxicol., 5, 171.
4. Federal Water Pollution Control Act, as Amended (33
U.S.C. 466 et seq.), (1970).
5. Pringle, B.H., D.E. Hissong, E.L. Katz, S.T. Mulawka,
1968. "Trace Metal Accumulation by Estuarine Mollusks",
J. San. Eng. Div., Proc. Am. Soc. of Civ. Eng. 94,455.
6. Swedish Natural Science Research Council. Sveavagen
166, Stockholm 23, Sweden. Metals and Ecology, 1969.
Symposium Stockholm.
7. U.S. Department of Health, Education and Welfare, 1965.
National Shellfish Sanitation Program Manual of Opera-
tions. Public Health Service Publication 33. U.S.
Government Printing Office, Washington, D.C. 20402.
8. U.S. Environmental Protection Agency, 1971. Analysis
of Pesticide Residues in Human and Environmental Samples.
Manual of Analytical Methods Prepared by Primate Research
Laboratories, EPA, Perrine, Florida 33157.
9. U.S. Environmental Protection Agency, 1971. Methods for
Chemical Analysis of Water and Wastes. Water Quality
Office, Analytical Quality Control Laboratory, Cincinnati,
Ohio 45202.
10. U.S. Government Code of Federal Regulations. Title 21
(updated daily by Federal Register).
11. Wooster, T., 1968. Existing and Potential Recreational
and Commercial Shellfish Production and Use in the San
Francisco, San Leandro, Richardson, San Rafael and San
Pablo Bays Complex. California State Department of Fish
and Game. Sacramento, California.
A 1.1 COVEftRMEIT PRMTM OFFICI 790-951
C-l
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