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

to station 15 1, then decreased steadily southward through stations 153, 152 and 156 (Figure 1 1).
Toxicity then again increased toward and into Sinclair Inlet.
I11 Elliott Bay, significant results of the MicrotoxTM tests were seen in stratum 23 (outer Elliott
Bay) and at nearby station 190 (mid Elliott Bay); at shoreline stations 176, 177, 1 15, and 183; at
stations 114 and 197 (west Harbor Island) and station 201 (east Harbor Island); and at stations
203-205 (Duwamish River). Five of these stations also displayed toxicity with the sea urchin
tests. As stated earlier, none of the MicrotoxTM test results indicated significant toxicity when
compared to the 80 and 90% Lower Prediction Limit (LPL) critical values generated for the 1997
data set (Long, et al., 1999a).
Human Reporter Gene System (Cytochrome P450)
Results of this test are illustrated as histograms for each station (Figures 14-18). High values are
indicative of a response to the presence of organic compounds, such as dioxins, furans, and
PAHs in the sediment extracts. Data are shown as benzo[a]pyrene equivalents (pglg). Using the
nationwide NOAA database and the 1997 PSAMPINOAA Northern Puget Sound Sediment
Quality study, critical values of >l1.1 and >37.1 pglg benzo(a)pyrene equivalentslg sediment
were calculated as the 80% and 90% upper prediction limit critical values for this toxicity
parameter (Long, et al., 1999a).
Minimal responses were observed in all samples from strata 1,2,4, and 5 in the northern region of
the study area (Figure 14), and strata 6-7 (Figure 15). With the exception of the sample taken at
station 141 (East Passage), stations in stratum 9 (Eagle Harbor); strata 8, 11, and 12 (Central
Basin); and station 135 in stratum 10 all displayed a response above the > 80% upper prediction
limit critical value. Results from three of these 14 stations also exceeded the 90% upper
prediction limit critical values (Figures 15, 17).
Slightly elevated responses (between the 80 and 90% upper prediction limits) were apparent in
samples from Liberty Bay (stations 143, 144, 146) and stations 148, 15 1, and 153 (Figures 15-
16). The cytochrome P450 HRGS responses in samples from stratum 16 diminished southward
into stratum 17 (no elevated results) and then increased again in strata 18-22 (Dyes and Sinclair
Inlets, and Port Washington Narrows) (Figure 16). Samples from 1 1 of the 15 stations in these
strata displayed cytochrome P450 HRGS responses above either the 80 or 90% upper prediction
limits.
Minimal cytochrome P450 HRGS responses were displayed in outer Elliott Bay (strata 23 and
24) (Figure 18). In contrast, samples from inner Elliott Bay and the Duwamish (strata 25-32)
gave the highest P-450 responses among all study samples. Cytochrome P450 HRGS assay
results exceeded either the 80 or 90% criteria values, with the exception of the sample from
station 190.
Summary
Several spatial patterns identified with results of all the tests were apparent in this survey. First,
samples from the Admiralty InletIPort Townsend area and much of the central main basin were
among the least toxic. Second, many of the samples from the Liberty Bay and Bainbridge basin
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