|Title:||Effect of field polarity in guiding salmon fingerlings by electricity|
|Author/Editor:||H William Newman|
|Institution:||U.S. Department of the Interior Fish and Wildlife Service, Special Scientific Report-Fisheries No. 319|
The relation of field polarity to fish guiding effectiveness was tested under controlled laboratory conditions by using a single–row electrode array sequentially energized so that: (1) positive polarity was always toward the upstream end, (2) positive polarity was always toward the downstream end, and (3) polarity alternated to cancel out polarity orientation. No difference in effectiveness was found demonstrating that fish guiding was due to avoidance rather than to electrotaxis. Variability, measured as variance, decreased as sample size increased but the mean effectiveness was similar for fish release lots of 15, 50, and 100 fish each.