Lack of Effect on Embryo Mortality and Fry Growth from Adult Coho Salmon Subjected to Electronarcosis Prior to Spawning

Abstract

AbstractThe use of electronarcosis as a fish immobilization technique has reemerged in recent years. Previous studies have investigated behavioral effects of the technique. But investigations of the physical and physiological effects on fish of electrical immobilization have focused on different electrical waveforms or higher power densities than are used for electronarcosis. This study was designed to determine whether there was a significant negative effect on embryo survival or fry growth among the progeny of adult Coho Salmon Oncorhynchus kisutch immobilized by electronarcosis prior to spawning as compared with being immobilized by tricaine methanesulfonate or not being immobilized at all (control). Embryo mortality in family lots ranged from 0.67% to 55.05%, with no statistically significant differences among the treatments and the control. There were significant differences in the size of fry from adults subjected to electronarcosis rather than the other two treatments, but in all cases the fry from adults treated with electronarcosis were larger. These findings support the continued use of electronarcosis as a fish immobilization technique.