The Retention of Coho Salmon (Oncorhynchus kisutch) Carcasses by Organic Debris in Small Streams

Abstract

Twenty marked coho salmon (Oncorhynchus kisutch) carcasses were placed in each of nine small streams on the Olympic Peninsula of Washington during the fall–winter spawning period. Distribution of the carcasses in 500 m of stream below each release site was followed for 4 wk. One week after placement, 78 of the 180 carcasses were found in the nine study reaches; 80% were found in the first 200 m downstream of the release sites. A general positive trend was observed between the number of carcasses retained and the amount of debris in the stream channel (r = 0.61). Terrestrial animals rapidly consumed carcasses during the experiment, and removed many of them to the riparian zone.