Kootenay Lake: Man's Effects on the Salmonid Community

A synopsis and evaluation is made of man's impact on Kootenay Lake salmonids since their first significant contact, perhaps less than 300 years ago. Exploitation of stocks for food by native Kootenay Indians was heavy in the late 1700s, probably surpassing present sport-fishery exploitation estimated at about 35 tons annually. Exploitation for fish-culture purposes never exceeded 7 tons annually, but because of restriction to a few spawning streams had serious effects on some local populations. Introduction of non-native fishes apparently was of little consequence to salmonids, whereas mysid introduction probably has produced growth enhancement in some stocks, especially kokanee. A similar but less obvious effect may be due to the marked cultural eutrophication occurring via heavy phosphate enrichment from a fertilizer plant. More serious and deleterious changes have been effected by stream habitat alteration resulting from mining, agriculture, and logging practices as well as from dam construction.