C
DDE CONCENTRATIONS IN THE BOCACCIO, SEBASTODES PAUC
INIS (AYRES, 1854),
AND SOME OTHER COMEERCIAL ORGANISMS OF MONTEREY BAYI
Stephen P. Fortmann“
Hopkins Marine Station of Stanford University
Pacific Grove, California
FOOTN
1. This work was supported in part by the Undergraduate Research
Participation Program of the National Science Foundation, Grant
IGY-5878
2. Permanent address:
INTRODUCTION
The work of several investigators has shown that DDT and
its derivatives DDE and DDD are widespread in the marine environment
(Risebrough, et al, 1967; Wurster, 1968). Only a few studies have
been completed concerning DDT levels in marine fishes (Risebrough,
1968; Parrish, 1969). Just one such study has been published (Odemar,
1968). As to commercial fishes from Monterey Bay (Monterey County,
California), analyses have been performed on only the anchovy (Rise-
brough, 1968; Kaplan, 1969), speckled sanddab (Phillips, 1969), English
sole (Risebrough, 1968), and starry flounder (Odemar, 1968).
There are four basic reasons why information on DDT levels
in marine fishes may be of importance. First, due to the biological
concentration of these pesticides, the levels now present in marine
fishes can give us a qualitative idea of the extent of pesticide pol-
lution in the marine environment. Second, the relative levels in
fishes feeding on different trophic levels can indicate whether or
not pesticides are concentrated in marine food webs as they are in
terrestrial food webs (Rudd, 1964). Third, it would be interesting
to know whether or not the levels of DDT might be high enough to sur-
pass the minimum level allowed in human food by the Food and Drug
Administration. Finally, the presence of DDT has been linked with
reproductive failure in birds and fresh water fishes (Macek, 1968:
Burdick, 1964; Currier, 1967), and levels might be high enough in
marine fishes to also pose a threat to them.
The investigations reported in this paper represent the
results of both a survey of natural DDE levels in six commercially
important organisms and a more detailed study of the relation be-
tween pesticide levels and age and weight in one of these fishes.
the bocaccio. Results indicated that the concentrations of DDE were
generally larger in animals feeding on higher trophic levels, and that
within a given species (Sebastodes paucispinis) the amount of pesticide
could be positively correlated to both age and weight.
METHODS
Specimens were either collected by the author or bought on
the commercial wharf in Monterey, and were analyzed the same day.
The following six species were analyzed for general DDE level: squid
(Loligo opalescans), cabezon (Scorpaenichthys marmoratus), speckled
sanddab (Citharichthys stigmaeus), blue rockfish (Sebastodes mystinus),
Northern anchovy (Engraulis mordax), and bococcio (S. paucispinis).
Squid, cabezon, blue rockfish, and bocaccio were analyzed by the
author, while the results shown for anchovy and sanddab were obtained
from the studies of Kaplan (1969) and Phillips (1969). These species
were selected for their commercial importance, position as to trophic
level, and availability. The specimens were divided into edible (flesh
and bone) and non-edible (head and viscera) portions, which were an-
alyzed separately so that the levels in both the portion normally
utilized for human consumption (which necessarily contained some bone)
and the levels in the entire organism could be determined separately.
In the investigation relating DDE levels to age and weight
in bocaccio, analysis was restricted to the liver. This was feasible
because the high lipid content of the liver makes it a repository for
DDE, and this tissue apparently has DDE levels which parallel those
levels found in the whole fish. Bocaccio was chosen because of the
high concentration of DDE found earlier in the study, its availability,
and the fact that this fish initially consumes only plankton but
gradually feeds on higher trophic levels as it matures. The fish
were aged by examination of their otoliths.
Tissues for analysis were digested in equal parts glacial
acetic and perchloric acids, the lipid portion extracted with nano-
grade hexane (Mallinckrodt), and the lipid removed before analysis
in a modified Davidow column (cf. Stanley and LeFavoure, 1965). The
chromatograms were performed isothermally (200° C) on a Beckman GC 4
gas chromatograph equipped with electron capture detector. The
carrier gas was helium. The column (3 per cent OF 1 on 80 - 100 mesh
'Chromosorb W') could not be used to obtain quantitative values for
other than DDE. Since DDE represents approximately 80 per cent of
the total DDT and its derivatives (Risebrough, 1969), it was used as
an index of pesticide level. All chemicals and other materials were
checked for purity before use to assure the absence of DDE, Glass¬
ware was repeatedly rinsed in nanograde hexane, which was then con-
centrated and checked for absence of DDE on the chromatograph.
RESULTS
Table One illustrates the levels of DDE found in the mus-
culature of the various organisms studied. For these determinations,
ten squid, twenty-five sanddabs, twenty-fiye anchovy, and one each
of the other fishes were analyzed. The values in lipid are considered
low due to technical difficulties. Note: (1) the levels of DDE in
the organisms relative to the level in sea water, (2) the higher levels
of DDE in organisms feeding on higher trophic levels, (3) the level
of DDE in the anchovy, which seems higher than would be expected con-
sidering the trophic level on which it feeds, and (4) the extremely
high values in lipid.
Table Two illustrates the levels of DDE for the whole or-
ganism in some of the same animals. Note the high concentrations re¬
corded for bocaccio.
Figure One shows the parts per million of DDE determined
for the livers of eleven bocaccio plotted against the age of the fish.
The line was computed statistically; the correlation coefficient is
0.678. The circled points denote fish caught by a commercial vessel
on 21 May, landed and analyzed on 22 May. The uncircled points in-
dicate fish that were caught by a commercial vessel on 26 May, landed
and analyzed on 27 May. On both days the vessel was operating just
north of Point Sur, California. The one very young fish was caught
for the author by personnel of the California Department of Fish and
Game working on the reef opposite Cabrillo Point on Monterey Bay.
Note the higher values in the fish caught on 26 May, especially where
the two groups overlap in age.
Figure Two shows ppm DDE plotted against the total weight
of the fish. The correlation coefficient is 0.711. Again note the
difference between the two groups of fish.
DISCUSSION
The data from the analysis of six species of marine organisms
show that DDE is present at concentrations far above that found in
sea water.
The data also indicate that DDE is probably concentrated
in marine food webs. The lowest values were found in squid, which
feed on low trophic levels and are mostly pelagic. Higher levels
were found in the cabezon, speckled sanddab, and blue rockfish, all
of which are second-level carnivores. The highest values were found
in the bocaccio, which is a high-level carnivore. The anchovy, which
filter-feeds on several trophic levels, probably has high concentrations
of DDE for two reasons. First, anchovy are not permanent residents
of the area, unlike the other organisms studied, and may have en-
countered high levels in the environment elsewhere. Second, anchovy
contain a higher per cent of lipid than the other species studied.
The concentration of DDE in lipid ranges from 6.18 to 58.5
ppm. The maximum legal level of DDT and its derivatives in beef fat
has been set by the Food and Drug Administration at 7 ppm. The level
in fish has not been permanently set. However, a limit of 5 ppm in
the whole fish, not in the fat, has been temporarily imposed. The
rationalization behind this dualism is not clear, but my data show
that if the limit in fish is set at the same level as in beef, most
of the fish of this study would exceed it.
Reproductive failure in fish exposed to DDT has been shown
in studies of the effect of DDT on reproduction in some fresh water
fish (Macek, 1968; Burdick, 1964; Cuerrier, 1967). Although this data
cannot be directly compared to my results, the data given in this paper
indicates that the levels of DDE in marine fishes are sufficiently
high to warrent further investigations on the possibility of repro-
ductive failure occurring now in marine fishes. Furthermore, the
high levels of DDE suggest that the effects of DDE as well as DDT on
reproduction should be studied.
The data from the analysis of bocaccio livers shows a great
variability in concentration of DDE. However, the correlation co-
efficients were high enough to indicate a definite trend toward
higher concentrations in both larger and older fish. By considering
fish caught on 26 May, and by considering fish only between 600 and
1700 grams in weight (to eliminate somewhat the differences between
the two groups due to size and age differences), I found that the DDE
levels were significantly different (p«0.002). Since the fish in
both groups were caught in approximately the same area, it can only
be concluded that the levels of DDE in bocaccio are highly variable.
The small number of fish analyzed limits the conclusions that can be
drawn.
In short, these studies show that the levels of pesticide
in the tissues of those organisms analyzed are sufficiently high to
suggest rather extensive pollution of the marine environment. Second.
there appears to be a rather general relationship between total DDE
concentration and trophic level, suggesting greater accumulation in
organisms feeding on higher trophic levels. While no direct inves-
tigations were made of whole fish, the combined results from viscera
and edible portions of the bocaccio suggest that some of these fish
may well be concentrating pesticides in excess of the levels now con¬
sidered allowable for human consumption. Finally, it is suggested
that some marine organisms may well be accumulating sufficient pest-
icide residues to interfere with normal reproduction.
/0
C
ACKNOWLEDGEENTS
I would like to thank the entire staff of Hopkins Marine
Station, especially Dr. Welton Lee, Richard Parrish, and Phillip
Murphy, for their help and advice in the preparation of this paper.
REFERENCE
Burdick, G. E., E.J. Harris, H.J. Dean, T.M. Walker, J. Shea, and D.
Colby. 1964. The accumulation of DDT in lake trout and the effect
on reproduction. Trans. Am Fish. Soc., 93 (2): 127-136.
Currier, J-P., J.A. Keith, and E. Stone. 1967. Problems with DDT in
fish culture operations. Naturaliste can., 94: 315-320.
Kaplan, Paul F. 1969. Personal communication.
Macek, Kenneth J. 1968. Reproduction in brook trout (Salvelinu
fontinalis) fed sublethal concentrations of DDT. J. Fish. Res.
Bd. Can., 25 (9): 1787-1796.
Odemar, Melvin W., et. al. 1968. A survey of the marine environment
from Fort Ross, Sonoma County, to Point Lobos, Monterey County.
California Department of Fish and Game. MRO Reference number
68-12.
Parrish, Richard A.
1969. California Department of Fish and Game.
Personal commumication.
Phillips, Gregory F. 1969. Personal communication.
Risebrough, Robert W., Daniel B. Menzel, D. James Martin, Jun., and
Harold S. Olcott. 1967. Nature, 216, Nov. 11, 1967: 589-591.
Risebrough, Robert W. 1968. Chlorinated hydrocarbons in marine écosystems.
Chemical Fallout. A Proceedings Publication of the Rochester
Conferences on Toxicity, (in press).
Risebrough, Robert W. 1969. Personal communication.
Rudd, Robert L. Pesticides and the Living Landscape. University of
Wisconsin Press; Madison, 1964.
Stanley, Ronald L. and Herbert T. LeFavoure. 1965. Rapid digestion
and clean-up of animal tissues for pesticide residue analysis.
J. Ass. off. agric. Chem., 48: 666-667.
Wurster, C.F. 1968. DDT reduces photosynthesis by marine phyto-
plankton. Science, 159 (3822): 1474-1475.
103
TABLE LEGENDS
Table One: Natural Levels of DDE in Muscle
Concentrations of DDE found in the edible portions of the
species analyzed. Values for sanddab and anchovy from
Phillips (1969) and Kaplan (1969). Value for sea water
is for DDT and its derivatives (Odemar, 1968). Ten squid.
twenty-five sanddab, twenty-five anchovy, and one each of
the other fishes were used for the determinations.
Table Two: Natural Levels of DDE in Whole Organisms
Concentrations of DDE found in the entire organism for
some of the animals listed in Table One. Value for sea
water is for DDT and its derivatives (Odemar, 1968).
FIGURE LEGENDS
Figure One: Concentration of DDE in Bocaccio Liver as a Function of Age
Statistically computed values givenifor line and correlation
coefficient (r). Circled points indicate fish caught on
21 May. Uncircled points denote fishecaught on 26 May.
Figure Two: Concentration of DDE in Bocaccio Liver as a Function
of Total Weight of the Fish
Statistically computed values given for line and correlation
coefficient (r). Circled points indicate fish caught on
21 May. Uncircled points denote fish caught on 26 May.
Organism
Sea Water
Squid
Cabezon
Speckled Sanddab
Blue Rockfish
Northern Anchovy
Bocaccio
Wet Weight (gms)
207.0
357.6
5.5
173.0
12.1
171.2
ppm DDE
0.000015
0.019
0.049
0.064
0.122
0.350
0.876
ppm DDE in Lipid
—
6.18
10.80
6.94
17.85
58.50
10
Organism
Sea Water
Squid
Cabezon
Blue Rockfish
Bocaccio
Total
Wet Weight (gms)
207.0
749.5
267.0
412.9
ppm DDE
.0.000015
0.019
0.197
0.357
1.780
ppm DDE in Lipid
11.0
11.7
56.2
106
ppm
DDE
2
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