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

Abstract
As a component of a three-year cooperative effort of the Washington State Department of
Ecology and the National Oceanic and Atmospheric Administration, surficial sediments from
100 locations in central Puget Sound were tested in 1998 to determine their relative quality. The
purpose of this survey was to determine the quality of sediments in terms of the severity, spatial
patterns, and spatial extent of chemical contamination, toxicity, and adverse alterations to benthic
infauna. The survey encompassed an area of approximately 732 km, ranging from Port
Townsend south to Des Moines in the central region of Puget Sound. Data from the chemical
analyses indicated that toxicologically significant contamination was restricted in scope to a
relatively minor portion of the region. However, sediments from several sampling locations
within Elliott Bay and other locations had relatively high chemical concentrations. Data from
toxicity tests indicated that many of the samples from inner Elliott Bay, including the lower
Duwamish River, and Sinclair Inlet were relatively toxic. Toxicity also was observed in
additional samples from locations scattered throughout the region. Wide ranges in several
numerical indices of benthic infaunal structure were observed, but the majority of samples had
diverse and abundant populations of benthos representative of conditions typical of the area.
Eighteen samples in which chemical concentrations were relatively high, toxicity was apparent,
and benthic communities appeared to be affected represented 1.1% of the study area. Samples in
which chemical contamination and toxicity were observed, but the benthos was relatively
abundant and diverse, represented 12.5% of the study area. Samples that were not contaminated,
not toxic, and had abundant benthic communities represented 49.1% of the survey area, while
samples which displayed either toxicity or chemical contamination (but not both) and abundant
benthic communities represented 37.3% of the survey area. Generally, upon comparison, the
number of stations displaying degraded sediments based upon the sediment quality triad of data
was slightly greater in the central Puget Sound than in the northern Puget Sound study, although
the percent of the total study area degraded in each region was similar (1.3 and 1.1%,
respectively). I11 comparison, the Puget Sound sediments were considerably less degraded than
those from other NOAA sediment surveys conducted nationwide.
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