The role of the geophysical template and environmental regimes in controlling stream-living trout populations

Canadian Journal of Fisheries and Aquatic Sciences
U.S. Forest Service, Weyerhaeuser Corporation
By: , and 

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Abstract

The importance of multiple processes and instream factors to aquatic biota has been explored extensively, but questions remain about how local spatiotemporal variability of aquatic biota is tied to environmental regimes and the geophysical template of streams. We used an individual-based trout model to explore the relative role of the geophysical template versus environmental regimes on biomass of trout (Oncorhynchus clarkii clarkii). We parameterized the model with observed data from each of the four headwater streams (their local geophysical template and environmental regime) and then ran 12 simulations where we replaced environmental regimes (stream temperature, flow, turbidity) of a given stream with values from each neighboring stream while keeping the geophysical template fixed. We also performed single-parameter sensitivity analyses on the model results from each of the four streams. Although our modeled findings show that trout biomass is most responsive to changes in the geophysical template of streams, they also reveal that biomass is restricted by available habitat during seasonal low flow, which is a product of both the stream’s geophysical template and flow regime. Our modeled results suggest that differences in the geophysical template among streams render trout more or less sensitive to environmental change, emphasizing the importance of local fish–habitat relationships in streams.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title The role of the geophysical template and environmental regimes in controlling stream-living trout populations
Series title Canadian Journal of Fisheries and Aquatic Sciences
DOI 10.1139/cjfas-2014-0377
Volume 72
Issue 6
Year Published 2015
Language English
Publisher National Research Council Canada
Publisher location Ottawa
Contributing office(s) Forest and Rangeland Ecosystem Science Center
Description 9 p.
First page 893
Last page 901
Online Only (Y/N) N
Additional Online Files (Y/N) N