Effects of Land Use on Aquatic Resources in the Puget Lowlands of Western Washington

Deforestation and urbanization in the Lake Washington/Cedar/Sammamish watershed over the last 100 years has had a dramatic influence on terrestrial and aquatic plants and animals.  As a consequence of habitat degradation and other factors, three native salmonid species have been listed as threatened under the ESA.  In response to the listing of Chinook salmon in 1999, local jurisdictions in the watershed have begun to implement a plan to recover listed species that relies heavily on scientific principles and data.  As part of the status and trends monitoring program of this plan, we used a stratified random sampling design to understand the relationship between land cover, hydrology, in-stream habitat metrics, and two biological indicators across 50 sites spread throughout the watershed.  Preliminary analyses indicate an inverse relationship between total impervious area and habitat quality and species richness (fish and invertebrates).  Information on current habitat quality in the watershed will help guide land use decisions based in the best available science.