Inter-calibration of three electric fishing techniques to estimate 0+ juvenile fish densities on sandy river beaches

• Published in: Fisheries management and ecology Vol. 12; no. 3; pp. 161 - 167
• Main Authors: JANÁČ, M., JURAJDA, P.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Science Ltd 01.06.2005
• Subjects: 0+ fish; electric fishing; point abundance sampling; rivers; sampling efficiency
• ISSN: 0969-997X; 1365-2400
• DOI: 10.1111/j.1365-2400.2005.00438.x

The efficiencies of three different techniques for 0+ fish point abundance sampling by electric fishing were tested on a sandy beach of the Morava River, Czech Republic. During direct electric fishing (DE), the operator immerses an anode fastened on an extension pole. During thrown anode electric fishing (TE), the anode is thrown at a distance from the bank. During remote electric fishing (RE), a pre‐positioned anode is activated after allowing sufficient time for fish to recolonise the area. The DE technique was found to disturb fish and that fish tend to escape, thereby reducing its efficiency (30% of efficiency of RE). There was no significant difference in relative abundance estimates or size structure of assemblages between DE and RE, but TE seemed to be a species selective technique on sandy river beaches, significantly overestimating relative abundance of bleak. Of the three techniques tested, RE was the most efficient and if time required for deployment could be reduced, it would be also the most suitable for monitoring 0+ fish assemblages on sandy river beaches.