Effects of fish wheels on fall chum salmon (Oncorhynchus keta): non-esterified fatty acids and plasma indices of stress

Thesis (M.S.) University of Alaska Fairbanks, 2003The effect of tagging and capture on plasma concentrations of cortisol, glucose, lactate, chloride, and non-esterified fatty acids (NEFA) in chum salmon was investigated. Adult chum salmon were captured in August-September 2000 and 2001 with a fish wheel on the lower Kantishna River. Tagged and untagged fish were subsequently captured on the lower Toklat River and sampled for blood. Tagged fish (males and females) at the Toklat recovery fish wheels had lower (P <0.04) plasma cortisol concentrations than untagged fish. Glucose concentrations were lower (P = 0.03) in tagged than untagged males but did not differ between tagged and untagged females. Lactate and chloride concentrations did not differ between tagged and untagged fish. Tagged chum salmon captured at the Toklat River recovery wheels had lower concentrations of NEFA (P = 0.02). Taken together, these results suggest there is a metabolic cost from capture and tagging using fish wheels