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Assessing the efficacy of single-pass backpack electrofishing to characterize fish community structure

Transactions of the American Fisheries Society

By:
, , and
DOI: 10.1577/1548-8659(2003)132<0039:ATEOSP>2.0.CO;2

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Abstract

Two-pass backpack electrofishing data collected as part of the U.S. Geological Survey's National Water-Quality Assessment Program were analyzed to assess the efficacy of single-pass backpack electrofishing. A two-capture removal model was used to estimate, within 10 river basins across the United States, proportional fish species richness from one-pass electrofishing and probabilities of detection for individual fish species. Mean estimated species richness from first-pass sampling (p??s1) ranged from 80.7% to 100% of estimated total species richness for each river basin, based on at least seven samples per basin. However, p??s1 values for individual sites ranged from 40% to 100% of estimated total species richness. Additional species unique to the second pass were collected in 50.3% of the samples. Of these, cyprinids and centrarchids were collected most frequently. Proportional fish species richness estimated for the first pass increased significantly with decreasing stream width for 1 of the 10 river basins. When used to calculate probabilities of detection of individual fish species, the removal model failed 48% of the time because the number of individuals of a species was greater in the second pass than in the first pass. Single-pass backpack electrofishing data alone may make it difficult to determine whether characterized fish community structure data are real or spurious. The two-pass removal model can be used to assess the effectiveness of sampling species richness with a single electrofishing pass. However, the two-pass removal model may have limited utility to determine probabilities of detection of individual species and, thus, limit the ability to assess the effectiveness of single-pass sampling to characterize species relative abundances. Multiple-pass (at least three passes) backpack electrofishing at a large number of sites may not be cost-effective as part of a standardized sampling protocol for large-geographic-scale studies. However, multiple-pass electrofishing at some sites may be necessary to better evaluate the adequacy of single-pass electrofishing and to help make meaningful interpretations of fish community structure.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Assessing the efficacy of single-pass backpack electrofishing to characterize fish community structure
Series title:
Transactions of the American Fisheries Society
DOI:
10.1577/1548-8659(2003)132<0039:ATEOSP>2.0.CO;2
Volume
132
Issue:
1
Year Published:
2003
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
Transactions of the American Fisheries Society
First page:
39
Last page:
46
Number of Pages:
8