Long-term population dynamics and conservation risk of migratory bull trout in the upper Columbia River basin

Canadian Journal of Fisheries and Aquatic Sciences
By: , and 

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Abstract

We used redd count data from 88 bull trout (Salvelinus confluentus) populations in the upper Columbia River basin to quantify local and regional patterns in population dynamics, including adult abundance, long-term trend, and population synchrony. We further used this information to assess conservation risk of metapopulations using eight population dynamic metrics associated with persistence. Local population abundances were generally low (<20 redds annually) and the majority of trends were either stable (85%) or declining (13%). Evidence of synchrony among populations was apparent but not related to fluvial distance between streams. Variability in annual abundances was 1.4–2.5 times lower in metapopulations than local populations, indicating moderate portfolio effects across the regional stock complex. Importantly, most metrics of conservation risk were uncorrelated with one another, emphasizing that multiple statistics describing population dynamics at various scales are needed for monitoring and assessing recovery. We provide a composite description of conservation risk based on local and regional population dynamics that can help inform conservation management decisions for bull trout and other freshwater fishes.

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Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Long-term population dynamics and conservation risk of migratory bull trout in the upper Columbia River basin
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/cjfas-2017-0466
Volume 75
Issue 11
Year Published 2018
Language English
Publisher Canadian Science Publishing
Contributing office(s) Northern Rocky Mountain Science Center
Description 9 p.
First page 1960
Last page 1968
Country United States
State Idaho, Montana
Other Geospatial Upper Columbia River basin
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