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Comparison of Electronarcosis and Carbon Dioxide Sedation Effects on Travel Time in Adult Chinook and Coho Salmon
Author(s) -
Keep Shane G.,
Allen M. Brady,
Zendt Joseph S.
Publication year - 2015
Publication title -
north american journal of fisheries management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.587
H-Index - 72
eISSN - 1548-8675
pISSN - 0275-5947
DOI - 10.1080/02755947.2015.1069427
Subject(s) - oncorhynchus , chinook wind , sedation , fish <actinopterygii> , carbon dioxide , sedative , environmental science , fishery , toxicology , chemistry , biology , ecology , medicine , anesthesia
Abstract The immobilization of fish during handling is crucial in avoiding injury to fish and is thought to reduce handling stress. Chemical sedatives have been a primary choice for fish immobilization. However, most chemical sedatives accumulate in tissues, and often food fishes must be held until accumulations degrade to levels safe for human consumption. Historically, there have been few options for nonchemical sedation. Carbon dioxide (CO 2 ) has been widely used for decades as a sedative, and while it does not require a degradation period, it does have drawbacks. The use of electronarcosis is another nonchemical option that does not require degradation time. However, little is known about the latent and delayed effects on migration rates of adult salmonids that have been immobilized with electricity. We compared the travel times of adult Chinook Salmon Oncorhynchus tshawytscha and Coho Salmon O. kisutch through a fishway at river kilometer (rkm) 4, and to rkm 16 and rkm 32 after being immobilized with either CO 2 or electronarcosis. Travel times of fish treated with either CO 2 or electronarcosis were similar within species. Because of the nearly instantaneous induction of and recovery from electronarcosis, we recommend it as an alternative to CO 2 for handling large adult salmonids. Received February 17, 2015; accepted June 27, 2015