Unintended effects of electrofishing on nongame fishes

Transactions of the American Fisheries Society
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Abstract

Most studies of injury associated with electrofishing have focused on game fishes, but few have given attention to cohabiting small nongame species. Under controlled laboratory conditions, we subjected small nongame cyprinids, ictalurids, and percids to a wide range of voltages and waveforms to examine potential harmful effects. Fish were treated with power levels distributed uniformly between the thresholds required to immobilize game fish and also were subjected multiple times to those thresholds to simulate the range of conditions that might exist in a heterogeneous electrical field formed during electrofishing in field situations. Across waveforms and species, the incidence of hemorrhages averaged 2% (range = 0–20%), the incidence of spinal injuries averaged 6% (range = 0–30%), and mortality averaged 16% (range = 0–90%). Continuous DC was generally less harmful than pulsed-DC waveforms; hemorrhages and spinal injuries tended to increase with high pulse frequencies, and mortalities tended to increase with low pulse frequencies. Ambiguities in the results were apparent, suggesting that some species may experience extensive harm, whereas others may not. Given the potential to harm numerically small populations and populations of imperiled species, we suggest (1) expanded efforts to overcome the power limitations that prevent effective use of continuous-DC electrofishing in many field situations and (2) pilot studies at geographic locations where numerically small populations of nongame species may be a concern.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Unintended effects of electrofishing on nongame fishes
Series title Transactions of the American Fisheries Society
DOI 10.1577/T09-225.1
Volume 139
Issue 5
Year Published 2010
Language English
Publisher Taylor & Francis
Contributing office(s) Coop Res Unit Atlanta
Description 7 p.
First page 1315
Last page 1321
Online Only (Y/N) N
Additional Online Files (Y/N) N