Reproductive Ecology and Body Burden of Resident ... - The Love Lab

Table 3. Variation in total length, weight, and moisture of kelp bass (KBA), kelp rockfish (KRO), and Pacific sanddab (PSD) sampled
from various sampling sites. a
Site b or F-statistic Total length (cm) Weight (g) Moisture (%)
KBA KRO PSD KBA KRO PSD KBA KRO PSD
PL1 --- 22.9 C 17.8 AB --- 206 BC 59 AB --- 71.1 B 81.2 A
NA1 --- 26.3 ABC 17.0 AB --- 284 BC 53 AB --- 72.1 B 80.5 A
PL2 --- 28.0 AB 17.9 AB --- 376 AB 70 AB --- 70.7 B 80.4 A
NA2 --- 23.3 BC 19.7 AB --- 200 C 83 AB --- 72.5 B 79.9 AB
PL3 --- 22.4 C 21.7 A --- 214 BC 119 A --- 69.8 B 81.8 A
NA3 --- 25.1 ABC 20.4 AB --- 234 BC 92 AB --- 72.5 B 80.0 AB
PL4 34.8 A --- 21.9 A 585 A --- 110 AB 67.3 A --- 79.9 AB
NA4 33.9 A --- 16.0 B 495 A --- 47 B 68.3 A --- 79.7 AB
PL5 --- 30.2 A 21.7 A --- 546 A 124 A --- 82.3 A 79.6 AB
NA5 --- 23.8 BC 20.7 AB --- 199 C 106 AB --- 81.5 A 77.8 B
F (df1,df2)
c,d
0.39 5.39**** 4.04*** 1.76 6.63**** 3.43 ** 1.12 65.65**** 4.77****
a
Within a column, geometric means (total length or weight) or angular-transformed means (moisture) followed by the same capital
letter are not significantly different (P>0.05) according to Tukey’s studentized range test.
b
Names and locations of sampling sites are given in Table 1.
c
For KBA, df1=1, df2=16; for KRO, df1=7, df2=72; for PSD, df1=9, df2=88.
d
Codes: *, P≤0.05; **; P≤0.01; ***, P≤0.001; ****, P≤0.0001.
Comparisons of Quantitative Elements at Oil Platforms and Natural Areas
Results from mixed models ANCOVA or ANOVA indicated that none of the 21 quantitative elements
consistently exhibited higher concentrations in fish from oil platforms than from natural areas. Out of
63 possible comparisons (21 elements measured in three fish species), 44 did not reveal significant differences
between HabTypes, whereas 11 comparisons indicated that elemental concentrations were significantly
higher at natural areas than at oil platforms. The remaining 8 comparisons exhibited significant
HabType*TL interactions, indicating that relative differences in elemental concentrations between Hab-
Types varied with TL of the fish species. Overall, our findings generally fail to support the hypothesis that oil
platforms are major sources of trace element contamination in resident marine fishes. Natural hydrocarbon
seeps, which are plentiful in northern portions of the Southern California Bight, could expose fish in natural
areas to trace elements and other contaminants, thus obfuscating spatial patterns that might otherwise be
attributable to oil platforms. Hornafius et al. (1999) noted that methane and non-methane hydrocarbon
emissions from natural seeps are largely responsible for air pollution in Santa Barbara County, and that
natural seeps produce oil slicks that evaporate to create abundant “tar balls” found on southern California
beaches. Moreover, in the Southern California Bight, some investigators have suggested that urban runoff
might contribute more trace elements (chromium, copper, lead, and zinc) and nutrients (nitrate and phosphorus)
than all other sources combined (Schiff et al. 2000).
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