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Validation of abundance estimates from mark–recapture and removal techniques for rainbow trout captured by electrofishing in small streams

North American Journal of Fisheries Management

By:
and
DOI: 10.1577/M04-081.1

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Abstract

Estimation of fish abundance in streams using the removal model or the Lincoln - Peterson mark - recapture model is a common practice in fisheries. These models produce misleading results if their assumptions are violated. We evaluated the assumptions of these two models via electrofishing of rainbow trout Oncorhynchus mykiss in central Idaho streams. For one-, two-, three-, and four-pass sampling effort in closed sites, we evaluated the influences of fish size and habitat characteristics on sampling efficiency and the accuracy of removal abundance estimates. We also examined the use of models to generate unbiased estimates of fish abundance through adjustment of total catch or biased removal estimates. Our results suggested that the assumptions of the mark - recapture model were satisfied and that abundance estimates based on this approach were unbiased. In contrast, the removal model assumptions were not met. Decreasing sampling efficiencies over removal passes resulted in underestimated population sizes and overestimates of sampling efficiency. This bias decreased, but was not eliminated, with increased sampling effort. Biased removal estimates based on different levels of effort were highly correlated with each other but were less correlated with unbiased mark - recapture estimates. Stream size decreased sampling efficiency, and stream size and instream wood increased the negative bias of removal estimates. We found that reliable estimates of population abundance could be obtained from models of sampling efficiency for different levels of effort. Validation of abundance estimates requires extra attention to routine sampling considerations but can help fisheries biologists avoid pitfalls associated with biased data and facilitate standardized comparisons among studies that employ different sampling methods.

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Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Validation of abundance estimates from mark–recapture and removal techniques for rainbow trout captured by electrofishing in small streams
Series title:
North American Journal of Fisheries Management
DOI:
10.1577/M04-081.1
Volume
25
Issue:
4
Year Published:
2005
Language:
English
Publisher:
Taylor & Francis
Publisher location:
London, UK
Contributing office(s):
Rocky Mountain Research Station
Description:
16 p.
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
Larger Work Title:
North American Journal of Fisheries Management
First page:
1395
Last page:
1410
Number of Pages:
16
Country:
United States
State:
Idaho
Other Geospatial:
Boise National Forest;Salmon-challis National Forest