Preliminary Results of Woody Debris Use by Summer Rearing Juvenile Coho Salmon (Oncorhynchus kisutch) in the Clearwater River, Washington

摘要

Preliminary results of a 3-year study evaluating the use of small woody debris bundles (evergreen trees) as habitat enhancement structures for juvenile coho salmon (Oncorhynchus kisutch) in the main stem Clearwater River is presented. The effectiveness of these structures in attracting and sustaining juvenile coho salmon during the summer and providing immigrants into wall-base channels during the fall was compared to that of naturally occurring debris and to areas with no woody debris (controls). The physical environment surrounding these debris structures was measured to determine the variables most important to summer rearing juvenile coho salmon.