Growth and Survival of Hormone-Sterilized Coho (Oncorhynchus kisutch) and Kokanee Salmon (O. nerka) in a Lacustrine Environment
1988 ◽
Vol 45
(8)
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pp. 1490-1494
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Keyword(s):
Coho (Oncorhynchus kisutch) and kokanee salmon (O. nerka) were sterilized using 17α-methyltestosterone treatments and released into a lacustrine environment. The treatment appeared to be successful and sizes at capture were similar for treated and control fish. Return rates of hormone-treated groups of fish were much lower than those of the control groups. Differences in return rates were assumed to be due to differences in survival rates but the possibility of differential vulnerability to the capture gear could not be ruled out. The proportion of treated kokanee in the catch increased with age, indicating that treated kokanee survived beyond the normal life span of the species.