We examined the levels of retention and utilization of 945 coho salmon (Oncorhynchus kisutch) carcasses released experimentally into seven spawning streams on the Olympic Peninsula, Washington. Most carcasses were retained in the streams and in adjacent forests, few were flushed beyond 600 m. Organic debris caught and held many carcasses. Much of the fish mass was consumed by 22 species of mammals and birds. The distances that carcasses drifted appeared to be related directly to the occurrence of freshets and inversely to debris load and carnivore scavenging. The capacity of many streams and rivers to retain carcasses has probably been reduced by human activities. The importance of coho carcasses to populations of carnivores and to the dynamics of lotic food webs merits additional study.

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Tributaries of the Clearwater River, Washington, support substantial populations of overwintering juvenile coho salmon Oncorhynchus kisutch. In 1983, a 4-year study was begun to determine if holes blasted in the mud substrate by explosives and subsequently flooded by creation of a small low-head dam could enhance these habitats economically. After treatment, overwinter survival and growth of coho salmon increased significantly.