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

data from all NOAA surveys (n=693, including central and northern Puget Sound), the average
and median RGS assay responses were 23.3 pglg and 6.7 pglg, somewhat lower than observed in
central Puget Sound - average of 37.6 pglg and median of 17.8 pglg.
The data from these comparisons suggest that the severity and spatial extent of enzyme induction
determined in the RGS test were roughly equivalent to those determined as the national average.
There were several survey areas in which toxicity was more severe and widespread and several
areas in which it was less so. The responses were clearly more elevated than those in samples
from northern Puget Sound.
Levels of Chemical Contamination
In central Puget Sound, there were 11 samples in which the mean ERM quotients exceeded 1 .O.
These samples represented an area of 3.6 km2, or about 0.5% of the total survey area. In the
northern Puget Sound study, none of the mean ERM quotients for 100 samples exceeded 1 .O. In
comparison, 6 of 226 samples (3%) from Biscayne Bay, FL, had mean ERM quotients of 1.0 or
greater (Long et al., 19990). Among 1068 samples collected by NOAA and EPA in many
estuaries nationwide, 5 1 (5%) had mean ERM quotients of 1.0 or greater (Long et al., 1998).
In central Puget Sound, there were 2 1 samples in which one or more ERA4 values were exceeded.
These samples represented an area of about 1 1.4 k m or 1.6% of the total area. In northern Puget
Sound, there were 8 samples (8%) representing about 9.5 km' (or 1.2% of the total area) in which
one or more ERMs were exceeded. In Biscayne Bay, 33 of 226 samples (15%) representing
about 0.7% of the study area had equivalent chemical concentrations (Long et al., 1996b). In
selected small estuaries and lagoons of Southern California, 18 of 30 randomly chosen stations,
representing 67% of the study area, had chemical concentrations that exceeded one or more
Probable Effects Level (PEL) guidelines (Anderson et al., 1997). hi the combined NOAAIEPA
database, 27% of samples had at least one chemical concentration greater than the ERM (Long et
al., 1998). In the Carolinian estuarine province, Hyland et al. (1 996) estimated that the surficial
extent of chemical contamination in sediments was about 16% relative to the ERMs. In data
compiled from three years of study in the Carolinian province, however, the estimate of the area
with elevated chemical contamination decreased to about 5% (Dr. Jeff Hyland, NOAA). In data
compiled by Dr. Hyland from stratified-random sampling in the Carolinian province, Virginian
province, Louisianian province, northern Chesapeake Bay, Delaware Bay, and DelMarVa
estuaries, the estimates of the spatial extent of contamination in which one or more ERM values
were exceeded ranged from about 2% to about 8%.
Collectively, the chemical data indicated that most of the central Puget Sound sediment samples
were not highly contaminated. Relative to effects-based guidelines or standards, relative to
previous Puget Sound studies, and relative to data from other areas in the U.S., the
concentrations of most trace metals, most PAHs, total PCBs, and most chlorinated pesticides
were not very high in the majority of the samples. However, the concentrations of nickel,
mercury, 4-methyl phenol, benzoic acid, some PAHs, and PCBs were relatively high in some
samples.
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