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Condition assessment of tidal wetlands of Washington, Oregon and California
Citation:
NELSON, W. G., H. LEE, II, J. O. LAMBERSON, F. A. COLE, C. L. WEILHOEFER, AND P. J. CLINTON. Condition assessment of tidal wetlands of Washington, Oregon and California. Presented at 4th National Conference on Coastal and Estuarine Habitat Restoration, Providence, RI, October 11 - 15, 2008.
Impact/Purpose:
EPA and State partners conducted an assessment of the condition of estuarine tidal wetlands of Washington, Oregon and California at 217 sites during the summer of 2002.
Description:
EPA and State partners conducted an assessment of the condition of estuarine tidal wetlands of Washington, Oregon and California at 217 sites during the summer of 2002. Dominant habitat types varied, although unvegetated sand or mud flats were the dominant habitat types for all three states. Oyster beds, gravel bottom, and intertidal seagrasses were recorded only in Washington and Oregon. California tended to have finer sediments, higher Total Organic Carbon, and higher levels of sediment contamination than estuarine intertidal areas in Washington and Oregon. Levels of sediment contamination west wide were low. Only 0.21% of the total intertidal area was estimated to exceed >5 Effects Range Low (ERL) concentrations for specific contaminants. The benthic community was dominated by polychaetes, oligochaetes and amphipods. Surprisingly, the single most abundant polychaete in the West Coast intertidal was the nonindigenous Manayunkia aestuarina, introduced from the Northeast Atlantic. San Francisco habitats were the most invaded with an average of almost 50% of the classified species per sample consisting of nonindigenous species. Puget Sound samples contained about 26% nonindigenous species compared to 40% to 44% for coastal Oregon and Washington. While sediment contamination issues are limited in extent, tidal wetlands of west coast estuaries have been broadly invaded by nonindigenous species.