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Refining boat electrofishing equipment to improve consistency and reduce harm to fish

North American Journal of Fisheries Management

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DOI: 10.1577/M04-094.1

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Abstract

A major concern with electrofishing is the standardization of sampling equipment and methods, particularly when collections are used to monitor spatial and temporal changes in fish communities. Standardization can not only ensure that stock assessment is consistent - that is, the data collected over time and space have equal meaning and are not influenced by differences in gear or gear application - but also reduce injury by constraining power to ranges that are likely to immobilize fish but unlikely to harm them. Standardization of electrofishing equipment requires adjusting power output to keep constant the amount of power transferred to fish in diverse water conditions. In this study, the power level thresholds required to immobilize and injure fish under controlled laboratory conditions were identified for various size-species combinations and applied to establish power minima and maxima suitable for successful and safe boat electrofishing. The target settings identified allowed survival of 99.4% of the fish collected and held for 2-3 h during field trials; all the mortalities were small fish (???53 mm long). The standardization procedure described herein may be adapted to single boats or fleets and can promote consistency in electrofishing, although it does not completely avoid harm to fish. Because electrofishing is an active capture method applied to changing microenvironments, complete standardization and total avoidance of harm to individual fish are not feasible with present technology, but standardization of controllable variables is advisable.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Refining boat electrofishing equipment to improve consistency and reduce harm to fish
Series title:
North American Journal of Fisheries Management
DOI:
10.1577/M04-094.1
Volume
25
Issue:
2
Year Published:
2005
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
North American Journal of Fisheries Management
First page:
609
Last page:
618