SOME LIFE HISTORY CHARACTERISTICS OF COHO SALMON 

 OF THE KARLUK RIVER SYSTEM, KODIAK ISLAND, ALASKA 



Benson Drucker^ 



ABSTRACT 



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, Oncoi^hynchus 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° N and long 154° W and 

 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, and 



^ National Marine Fisheries Service, Auke Bay Fish- 

 eries Laboratory, Auke Bay, Alaska 99821 ; present ad- 

 dress: National Marine Fisheries Service, Technical 

 Advisory Division, Interior Building, Washington, D.C. 

 20235. 



" Nelson, Richard C. 1968. Alaska catch and pro- 

 duction, commercial fisheries statistics. Alaska Dep. 

 Fish Game, Stat. Leafl. 17. 29 p. (Unpublished.) 



Figure 1. — The Karluk River system, Kodiak Island, 

 Alaska. 



Manuscript accepted July 1971. 



FISHERY BULLETIN: VOL. 70, NO. 1, 1972. 



79 



