Salmonid Habitat in Urban Streams of the Puget Sound Lowlands

Abstract

Urban streams and wetlands are some of the most extensively degraded and disturbed aquatic ecosystems in the country. To assess the cumulative effects of urbanization and development, the watersheds of 22 small streams in the Puget Sound lowlands were extensively studied over a 3-year period. The watersheds included rural, suburban, and urban land uses. The study included detailed watershed characterization, in-stream habitat assessment, riparian zone surveys, macroinvertebrate sampling, hydrologic monitoring, and chemical water-quality analyses. The results suggest that resource managers should concentrate on the preservation of high-quality stream systems through the use of land-use controls, riparian forest buffers, and protection of critical in-stream salmonid habitat. Enhancement and mitigation efforts should be focused on watersheds where ecological function is impaired but not lost. It is apparent that restoration measures will probably be ineffective unless watershed-level disturbances such as changes in the hydrologic regime and loss of riparian forests are addressed in addition to addressing in-stream habitat features and water quality.