Sediment Quality in Puget Sound Year 2 - Center for Coastal ...

Both percent urchin fertilization and cytochrome P450 HRGS induction were significantly
correlated with the concentrations of most individual low molecular weight PAHs (LPAH) and
the sums of these compounds (Table 18). The correlations with cytochrome P450 HRGS
induction were very similar among the LPAHs, suggesting these compounds co-varied with each
other to a large degree. The highest correlation of any toxicity test with any chemical parameter
was between the cytochrome P450 HRGS and the HPAHs (rho = 0.718-0.946, pg.OOOl)(Table
19). The cytochrome P450 HRGS assay is known to be sensitive to, and was designed to detect,
the presence of HPAH. Correlation coefficients, while also highly significant, were lower with
urchin fertilization (rho = -0.413- -0.623, pg.0001). Microbial bioluminescence generally was
not highly correlated with the concentrations of these compounds, and amphipod survival, as
with the metals, was not correlated with either LPAH or HPAH results (Table 19).
The concentrations of the sums of 13 dry-weight normalized PAHs (national guidelines; Long et
al., 1995) and 15 TOC-normalized concentrations (Washington State Sediment Management
Standards; Chapter1 73-204 WAC, 1995) were highly correlated with percent urchin fertilization
and cytochrome P450 HRGS results. Fertilization success was highest among samples with the
lowest concentrations (Figures 28,29). However, fertilization success did not decrease steadily
with increasing concentrations and the only sample in which the total PAH concentration
exceeded the ERM was not toxic; thereby suggesting that fertilization success was not controlled
by these substances.
In contrast to the data from the urchin tests, enzyme induction in the cytochrome P450 HRGS
tests was consistently lowest in samples with lowest total PAH concentrations, increased steadily
as concentrations increased above the ERL levels, and generally was highest in samples in which
the ERM was exceeded (Figure 30). Normalization of the PAH concentrations to TOC content
decreased the correlation (Figure 3 1) due to increased variability in the association.
Results of the four toxicity tests were also examined for relationship with the concentrations of
various butyltins, phenols, and miscellaneous organic compounds (Table 20). No significant
correlations were seen between amphipod survival and these compounds. Fertilization success
was highly significantly correlated with the two butyltin compounds, and began to diminish as
the concentrations of dibutyltin exceeded 60 ppb and as tributyltin concentrations exceeded 200
ppb (Figures 32,33). Percent fertilization, however, was very high in the sample from station
187 in which the tributyltin concentration was highest. Fertilization success was also
significantly correlated with dibenzofuran. In the microbial bioluminescence tests,
bioluminescence activity was highly correlated to, and decreased steadily with, increasing
concentrations of benzoic acid (Figure 34). Similar to results in the urchin tests, cytochrome
P450 HRGS induction showed a strong degree of correspondence with concentrations of both
dibuyltin and tributyltin, and dibenzofuran. Cytochrome P450 HRGS induction seemed to
increase when dibutyltin concentrations exceeded about 80 ppb, and tributyltin and dibenzofuran
concentrations exceeded about 100 ppb (Figures 35-37).
Cytochrome P450 HRGS induction was significantly correlated with the concentrations of 4-4'
DDE and total DDT. Both percent urchin fertilization and cytochrome P450 HRGS induction
were significantly correlated (cytochrome P450 HRGS to a greater degree) with the
concentrations of individual PCB compounds, and the sums of these concentrations (Table 2 1).
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