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laboratory (Wardle, 1972). In the last two samples, February 1980
and June 1980, reference plaice were sampled very rapidly a^ter capture
and their blood glucose values represent the normal unstressed values.
Plaice from the Abers were stressed by capture and showed a hyperglycemic
response, suggesting some recovery of physiological function
with time. These data show some of the difficulties in using blood
glucose concentration as an index of stress in fish. If blood samples
cannot be taken immediately after the fish are captured, capture- induced
responses may obscure any due to pollution.
Liver glycogen concentrations in fish from the last two collections
were highly variable (Table 21). Because of extremely large standard
deviations, no patterns could be discerned.
Total cholesterol and high density lipoprotein (HDL) cholesterol
concentrations in the blood of plaice were measured in sampels from the
last two collecting trips (Table 22). The general trend was for total
cholesterol to be elevated and HDL cholesterol concentration to be
depressed in fish from the two oil-contaminated Abers. Several of these
differences were statistically significant. As a result, HDL cholesterol
as percent of total cholesterol was lower in plaice from Aber Benoit and
Aber Wrac'h than in plaice from the reference station at lie Tudy.
Concentration of liver-free ascorbic acid was measured in plaice
from all five sampling trips (Table 23). In all but the February 1980
sample, liver ascorbate concentrations in plaice from oil-contaminated
Aber Benoit and Aber Wrac'h were substantially lower than concentrations
in livers of plaice from reference stations. In four cases, the difference
was statistically significant. In the February collection, the
pattern was reversed. Reference fish contained hepatic ascorbate concentrations
significantly lower than concentrations in livers of fish from
the two Abers. At this time, all the reference fish were gravid females
ready to spawn. Only a few of the fish from the Abers were in this condition.
It is highly likely that the extreme depletion of liver ascorbate
reserves in the reference fish is the result of ascorbate mobilization
for gonadal maturation and ovogenesis. These gravid reference fish also
had relatively low hepatic glycogen reserves (Table 21) .
Adductor muscle-free amino acid profiles and concentrations were
measured in oysters from the first three collecting trips
Total free amino acid concentrations were always lower in
(Tables 24-26).
adductor muscles
of oysters from oil-contaminated Aber Benoit and Aber Wrac'h than in
adductors of oysters from reference stations. This difference cannot
be attributed to differences in seawater salinity between Aber and
reference stations, since all stations had salinities in the 30-34 o/oo
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