Publication Summary

Monitoring of marine waters was initiated in 1967 by the Washington State Department of Ecology in order to assess water quality in Puget Sound, Grays Harbor, and Willapa Bay. Data are currently collected monthly for this ongoing, long-term monitoring effort by the Marine Waters Monitoring Program. Monitoring of various water quality parameters during wateryears 1994 and 1995 occurred at 24 and 30 stations, respectively, in Puget Sound and at five stations each year in both Grays Harbor and Willapa Bay (WY 1994 = October 1993 through September 1994). In this report, along with the WY data, five indicators of marine water column environmental condition are presented and discussed.

Monitoring of marine waters was initiated in 1967 by the Washington State Department of Ecology in order to assess water quality in Puget Sound, Grays Harbor, and Willapa Bay. Data are currently collected monthly for this ongoing, long-term monitoring effort by the Marine Waters Monitoring Program. Monitoring of various water quality parameters during wateryears 1994 and 1995 occurred at 24 and 30 stations, respectively, in Puget Sound and at five stations each year in both Grays Harbor and Willapa Bay (WY 1994 = October 1993 through September 1994). In this report, along with the WY data, five indicators of marine water column environmental condition are presented and discussed.

Climatic conditions of WY 1994-95 were characterized by lower than normal precipitation in WY 1994, particularly in the fall and winter. Air temperatures were generally slightly above average throughout the 2-year period. Runoff of two major rivers (Skykomish and Chehalis) was approximately 70% of the median flow in WY 1994 and approximately 110% of the median flow in WY 1995. Many features of these weather and flow conditions were evident in the sea-surface temperatures and salinities of Puget Sound stations. Grays Harbor and Willapa Bay stations showed less correlation and may be more influenced by oceanic input.

The stratification characteristics of stations were classified into four groups: persistent, seasonal, episodic, and weak. The majority of the Puget Sound monitoring stations were either persistently (18 out of 35 stations) or seasonally (10 out of 35 stations) stratified. The degree of stratification has implications for water column dissolved oxygen (DO) concentrations.

DO concentrations <5 mg/L were measured at 16 stations during WYs 1994-95. In southern Hood Canal, East Sound, Penn Cove, and Budd Inlet DO concentrations were <3 mg/L. Observations of low DO primarily occurred in late summer to early fall but in southern Hood Canal occurred year-round. Similar DO concentrations have been exhibited at these stations in previous wateryears, but conditions at some stations were not as severe.

Very high ammonium-N concentrations (>0.14 mg/L) were seen in East Sound and Elliott Bay, with ten other stations showing high concentrations (>0.07 mg/L). Consecutive months of <0.01 mg/L surface nitrate+nitrite-N are used to indicate stations likely to be affected by eutrophication.

Fecal coliform bacteria counts >14 organisms/100 mL were found at twelve Puget Sound stations and four coastal stations during WY 1994-95. Of these, contamination in Grays Harbor, Willapa Bay (near the Willapa River), and Commencement Bay appeared chronically persistent. The highest (1000′s orgs./100 mL) and most persistent counts were in Grays Harbor.