C
BST
Pagurus samuelis were collected from eight locations
on the California coast between San Francisco and Los
Angeles. It was found that DDT residue concentration
levels at gix of the eight locations were relatively low,
ranging from .6 ppb to 6.9 ppb. While levels at Monterey
Harbor (mean value 36 ppb) and White's Point (mean value
840 ppb) were much higher. Some possible explanations
for this difference are given. There was no significant
difference between levels in males as compared to ovigerous
females of the same populations.
TAo
INTHODUCTION
The chlorinated hydrocarbon pesticide DDT and its
metabolites DDD and DDE are widely distributed in the
environment today. DDT residues enter the oceanic en-
vironment through agricultural runoff, rivers, sewage
disposal and settling of airborne particles (Freed, 1970;
Peterle, 1970). DDT residues have a very low solubility
in water and readily absorb to particulate material, es-
pecially organic particles (Odum, et. al., 1969; Peterle,
1970). In contrast, the solubility of DDT residues in
lipids and other organic material is very high (Wurster,
1969). Also, DDT and its metabolites are among the most
persistent of the organochloride pesticides in biological
systems (Macek, 1970). DDT residues are readily acquired
by organisms through direct uptake from water or through
assimilation from food. They become concentrated in
body lipid stores at levels much greater than those of
the environment (Cox, 1971) and there is a biological
magnification of DDT residue concentrations at successive
steps and trophic levels (Woodwell, 1969; Harrison, et.
al., 1970).
The acoumulation of DDT residues by decapod crusta¬
ceans has been reported by Odum, et. al. (1969) and
Dimond, et. al. (1968). The toxic effects of DDT have
been reported by Eisler (1969) for Pagurus longicarpus
and by Poole and Williams (1970) for the larvae of two
species of Cancer. There are no previous reports of
T residue levels in the family Paguridae. Paguru
samuelis was chosen for study because it is abundant
along the Californian rocky coast, occurs high in the
intertidal zone and is therefore easy to collect (Bollay,
1964). Samples were taken from various areas and tested
to determine natural levels of DDT residues in Pagurus
amuelis.
EO
-
METHODS AND MATERIALS
Pagurus samuelis were collected from eight areas on
the California coast between San Francisco and the Palos
Verdes Peninsula. (Fig. 1)
A) Pacifica: latitude 37° 35'; near the San Pedro
Sewage Treatment Plant and outfall.
B) Monterey Harbor: latitude 36° 36'; under Fisherman's
Wharf, Monterey Harbor, and for about 100 meters
northwest. This area is within the Coast Guard
breakwater.
C) Mussel Point, Pacific Grove: latitude 36° 37';
east of Hopkins Marine Station of Stanford Uni-
versity.
D) Point Pinos, Pacfic Grove: latitude 36° 38'; within
60 meters of the outfall from the Pacific Grove
Sewage Treatment Plant.
E) Carmel Mission Point, center of Carmel Bay:
latitude 36° 32'; south side of the point, about
500 meters north of the outfall from the Carmel
Sewage Treatment Plant.
F) Monastery Beach, south end of the Carmel Bay;
latitude 36° 31'; about 700 meters south of the
outfall from the Carmel Sewage Treatment Plant.
The currents run generally southward from the
outfall.
G) Malpaso Creek, Monterey County: latitude 36% 28';
about 500 meters south of the creek on undeveloped
private land which is locked to the general public.
H) White's Point, Palos Verdes Peninsula: latitude
33° 43'; from the beach closest to the Los Angeles
County sewer outfall. This is one of the largest
primary treatment outfalls on the West Coast.
Samples were all taken at low tide near the upper
intertidal limit of the brown alga Egregia. One hundred
Pagurus samuelis were taken from each study area. In
the laboratory, they were removed, without injury, from
their shells by removing the tip of the shell and poking
635
the crab out. When possible five pooled samples of males
and five pooled samples of females were tested from each
area. Among the females, only ovigerous individuals were
used, and the eggs borne externally were removed before
digestion to assure a more uniform population. Each
pooled sample consisted of from three to five whole in-
dividuals depending on weight. The wet weights of indi-
viduals ranged from.5 g to 1.5 g. Total sample weights
ranged from 1.88g to 4.26 g wet weight.
Crabs were placed in small glass vials, digested in
a 50-50 mixture of 60% perchloric and glacial acetic acids,
and extracted with hexane (Stanley and Le Favoure, 1965).
All glassware was cleaned by first washing, then rinsing
in distilled water and finally heating for eight hours
at 375° C. Cleanup was done on a silica gel micro-
column (Kadoum, 1967) with .05 g of Nuchar Attaclay added
to remove pigments. The column was eluted with approxi-
mately 8 ml of pesticide grade benzene. Approximately
958-99% of the pesticide residues originally present were
recovered after digestion and cleanup. Samples were then
evaporated down to desired concentrations and aliquots
were injected into a Beckman GC-4 gas chromatograph
fitted with two electron capture detectors. The column
was Pyrex glass, 6', packed with a l to 1 mixed bed of
58
5% DC200 and 6% QFl on 80-100 mesh Chromasorb W (acid
washed and DMCS treated). The column temperature was
200° C and the inlet temperature 220° C. The carrier gas
was helium. The identity of the DDT, DDD and DDE peaks
was periodically checked using the partition coefficients
established by Bowman and Berzoa (Berzoa et. al., 1969).



RESUE
AND DISCUSBTON
DDT residues in Pagurus samuelis are shown in
Table 1 and Figure 2. The levels of DDT residues are
low in six of the eight study areas with combined means
for the two sexes ranging from .6 ppb (parts per billion)
wet weight to 6.9 ppb. The remaining two study areas
have much higher concentration levels: Monterey Harbor
has a mean value of 36 ppb total DDT residues and White's
Point has a mean value of 840 ppb total DDT residues.
Statistical analysis of the data was carried out using
the Student's t-test (Simpson, et. al., 1960). The
difference in levels of DDT and its metabolites between
males and ovigerous females in the same population was
not statistically significant in any of the eight popula-
tions. Thus I felt justified in combining the males and
females when computing the mean concentration values for
each area. The populations at Monterey Wharf and White's
53
Point are statistically different from the remaining six
populations and from each other at the.Ol level. The
remaining six populations do not show statistically sig-
nificant differences at the.05 level using this test.
The mean pesticide residue values for the Monterey
Harbor and White's Point do have relatively large standard
deviations. This can be partially explained by the
feeding habits of Pagurus samuelis. These crabs are
scavengers on both plant and animal materials. As a
result their intake of DDT residues by assimilåtion from
food may vary widely from individual to individual. This
may be particularly relevant at the Monterey Harbor. Here
fish are cleaned, and heads and viscera are often thrown
off the pier; fish parts were observed in the area when
Pagurus were collected. Also located in this area is a
large storm drain. The runoff from the drain spills out
approximately 10 meters from the rocks where half of the
Pagurus were collected. This drain accomodates runoff
from yards and gardens in the Monterey area and may be
another source of DDT input. Although the use of DDT
is now regulated by the state, homeowners may still be
using DDT that was purchased before regulations came into
effect.
The extremely high values found in the Pagurus from
53
White's Point correlates to similarly high values found
by Burnett (1971) in the Emerita analoga of this area.
The effluent from the L.A. County sewage system is dis-
charged from a diffuser that begins approximately 1.6
kilometers offshore at White's Point and diffuses for
another 1.6 kilometers. The sole producer of DDT in the
United States is located in L.A. county and disposes of
its effluent into the L.A. county sewer system (Burnett.
1971). Although the amount of DDT residues in this eff-
luent has decreased considerably in the last year, the
levels are still high, approximately 36.5 metric tons
per year (Cox, 1971). This probably accounts for the
majority of the DDT residues in this area.
The effects of DDT residues on members of the
Paguridae family are not yet well documented. Eisler
(1969) has established toxicity levels for several pesti-
cides for Pagurus longicarpus. The subtle, chronic effects
of pestioide residues may, however, be more important than
such dramatic short term effects. The effects of these
residues on reproductive behavior and larval survival may
prove to be particularly significant. It is perhaps into
these areas that research should now be directed.
SUMMARY
Pagurus samuelis were collected from eight locations
on the California coast between San Francisco and Los
Angeles. It was found that DDT residue concentration
levels at six of the eight locations were relatively low,
ranging from .6 ppb to 6.9 ppb. While levels at Monterey
Harbor (mean value 36 ppb) and White's Point (mean value
840 ppb) were much higher. Some possible explanations
for this difference are given. There was no significant
difference between levels in males as compared to ovigerous
females of the same populations.
ACKNOWLELUEMENTS
I would like to thank the faculty, students and
staff of Hopkins Marine Station for a very enjoyable
experience. In particular, I express my great appre-
ciation to Dr. Donald Abbott, Robin Burnett, Jim Rote
and Judy Peters for their help throughout this project.
I would also like to thank Phil Murphy for his help with
the gas chromatograph. Finally I thank Marsh Youngbluth
for all his help on the volleyball court.
C
0
0.
BLE C
Table 1: means, standard deviations and ranges for
males (all samples combined), females (all
samples combined) and total population for
each study area.
C
GURE CAE
IONS
Figure 1: map showing geographical locations of the
eight study areas.
Figure 2: DDE, DDD and DDT concentrations for all samples.
Ordinates show pesticide residues in parts
per billion wet weight: black (DDE), stippled
(DDD), white (DDT). Numbers on abscissa desig.
nate individual samples.
Location
PACIFICA
MON
ERE
HA
BOR

CSSLE
POINT
OIN
PINOS
MEL
MISSION
POI)
2
NAS
EA
BEACH
MALPASO
CREEK
——
A1.
POINT
DDE
mean
3.D.
.8
1.2
1.0
Org
.1
12
1.8
1.1
13
610
13
3.2
1.7
1.9
619
1.8
2.8
7.0
1.4
6.8
69
6.9
2.1
2.6
.5
3.0
1.1
.8
679
2.3
.8
.1
.8
. 3
619
.8
.8
.4
.1
5
.6
3
649
130
840
54
700
C+9 760 410
549
DD
DDD
range mean S.D.
mange mean S.D. ran
5-
1.6
1.1-
1.3
5-
1.
2.9- 16 5.3 11-
8.
5.3 2.0
26
13
8.9
9.4 20-
8.0
7.4 5.1 3.3- 18
20
16
11-
8.0
2.9- 17
6.4 4
8.1
20
1.0-
2.7
1.1-
3.2
1.0-
3.2
1.2-
11
5.1-
8.
4.2-
11
2.1-
3.U
1.9-
1.1
1.9-
1.1
1.0
.6-
1.
.6-
1.7
.4-
1.4
.3-
.6
3-
1.4
9.3 14-
310-
11- 17
20 8
1.600
23 6.6 17-
70
25-
42 12
650
23 7.1 25-
310-
11
29 14
54
1.600
35
123459 123
PACIFICA
U
ol
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MUSSEL POINT
lo¬
UU
s
2345
1234
POINT PINOS
123
CARMEL MISSION POINT

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12345
MONASTERY BEACH


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MALPASO CREEK
70-
60
50
40
30-
20-
1600
900
800
700
600
500


400
300
20o-
00
L
5
12345 91 2345
MONTEREY HARBOR
§ 123459 23
WHITE'S POINT
596
POINT PINOS
MUSSEL POINT¬

CARMEL MISSION POINT
MONASTERY BEACH

MALPASO CREEKfG
San Francisco
Bay
Sanfadiseo
PACIFICA A
—
Monterey
Bay
RMOMEREY HARBOR
Carmel River

)
Long Beach

San Pedro Bay
WHITE'S POINT
546
1
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