Spatial and temporal Brook Trout density dynamics: Implications for conservation, management, and monitoring

Transactions of the American Fisheries Society
By: , and 

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Abstract

Many potential stressors to aquatic environments operate over large spatial scales, prompting the need to assess and monitor both site-specific and regional dynamics of fish populations. We used hierarchical Bayesian models to evaluate the spatial and temporal variability in density and capture probability of age-1 and older Brook Trout Salvelinus fontinalis from three-pass removal data collected at 291 sites over a 37-year time period (1975–2011) in Pennsylvania streams. There was high between-year variability in density, with annual posterior means ranging from 2.1 to 10.2 fish/100 m2; however, there was no significant long-term linear trend. Brook Trout density was positively correlated with elevation and negatively correlated with percent developed land use in the network catchment. Probability of capture did not vary substantially across sites or years but was negatively correlated with mean stream width. Because of the low spatiotemporal variation in capture probability and a strong correlation between first-pass CPUE (catch/min) and three-pass removal density estimates, the use of an abundance index based on first-pass CPUE could represent a cost-effective alternative to conducting multiple-pass removal sampling for some Brook Trout monitoring and assessment objectives. Single-pass indices may be particularly relevant for monitoring objectives that do not require precise site-specific estimates, such as regional monitoring programs that are designed to detect long-term linear trends in density.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Spatial and temporal Brook Trout density dynamics: Implications for conservation, management, and monitoring
Series title Transactions of the American Fisheries Society
DOI 10.1080/02755947.2013.847878
Volume 34
Issue 2
Year Published 2014
Language English
Publisher Taylor & Francis
Contributing office(s) Coop Res Unit Leetown
Description 11 p.
First page 258
Last page 269
Country United States
State Pennsylvania
Online Only (Y/N) N
Additional Online Files (Y/N) N