CHARACTERISTICS OF STREAM CHANNELS SUPPORTING COHO SALMON IN NORTHERN CALIFORNIA

Coho salmon (Oncorhynchus kisutch) are threatened with exinction in coastal northern California streams. Few streams are known to support stable coho runs. Streams supporting spawning populations in western Marin County and western Sonoma County have been surveyed to assess habitat conditions. Surveys focused on spawning gravel size distributions at known or likely spawning sites determined by use of a McNeil bed sampler. Additional habitat information pertaining to surface sediment size distributions, sediment stored in gravel bars, pools, and LWD abundance was collected. These quantitative observations may provide useful perspective on the objectives of stream and watershed restoration projects intended to benefit O. kisutch. Consideration of watershed conditions at these locations may also inform restorationists regarding the type and magnitude of land use and watershed management known to be consistent with population persistence.