Some life history characteristics of coho salmon of Karluk River system

This paper contains data on some life history characteristics of the coho salmon of the Karluk River system, Kodiak Island, Alaska: age, fecundity, length, and egg size of adults; and migration charac-teristics, age, and size of smolts. The greater age at maturity of Karluk coho salmon (4 and 5 years) because of the longer freshwater residence of the juveniles is unique among reported North American stocks and may result in greater freshwater mortality but less marine mortality because the smolts are larger when they enter the ocean. Fecundity of Karluk coho salmon also differs from that reported for other North American stocks in that they are extremely fecund-more similar to Asiatic stocks of the Kamchatka Peninsula. Coho salmon, Oncorhynchus kisutch, are widely distributed along the Pacific coast of North America and occur in commercially harvestable quantities from northern California to north-western Alaska. About one-third of the total North American commercial catch comes from Alaska waters, where from 1960 to 1968 the average annual catch of 16 million pounds was valued at almost $3.5 million to the fishermen: The amount of biological research on coho salmon in Alaska is small, and published scientific re-ports on Alaska coho salmon stocks are very few. In this paper I present data on some life his-tory characteristics of the coho salmon of the Karluk River system. This system is located on the southwest side of Kodiak Island, Alaska, at approximately lat 57 0 N and long 1540 Wand includes Karluk Lake, tributaries to the lake, Thumb and O'Malley Lakes, and Karluk River (Figure 1). Information is presented on age, fecundity, length, and egg size of coho salmon adults; and migration characteristics, age, an