A simple prioritization tool to diagnose impairment of stream temperature for coldwater fishes in the Great Basin

North American Journal of Fisheries Management
By: , and 

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Abstract

We provide a simple framework for diagnosing the impairment of stream water temperature for coldwater fishes across broad spatial extents based on a weight-of-evidence approach that integrates biological criteria, species distribution models, and geostatistical models of stream temperature. As a test case, we applied our approach to identify stream reaches most likely to be thermally impaired for Lahontan Cutthroat Trout Oncorhynchus clarkii henshawi in the upper Reese River, located in the northern Great Basin, Nevada. We first evaluated the capability of stream thermal regime descriptors to explain variation across 170 sites, and we found that the 7-d moving average of daily maximum stream temperatures (7DADM) provided minimal among-descriptor redundancy and, based on an upper threshold of 20°C, was also a good indicator of acute and chronic thermal stress. Next, we quantified the range of Lahontan Cutthroat Trout within our study area using a geographic distribution model. Finally, we used a geostatistical model to assess spatial variation in 7DADM and predict potential thermal impairment at the stream reach scale. We found that whereas 38% of reaches in our study area exceeded a 7DADM of 20°C and 35% were significantly warmer than predicted, only 17% both exceeded the biological criterion and were significantly warmer than predicted. This filtering allowed us to identify locations where physical and biological impairment were most likely within the network and that would represent the highest management priorities. Although our approach lacks the precision of more comprehensive approaches, it provides a broader context for diagnosing impairment and is a useful means of identifying priorities for more detailed evaluations across broad and heterogeneous stream networks.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title A simple prioritization tool to diagnose impairment of stream temperature for coldwater fishes in the Great Basin
Series title North American Journal of Fisheries Management
DOI 10.1080/02755947.2015.1115449
Volume 36
Issue 1
Year Published 2016
Language English
Publisher Taylor & Francis
Contributing office(s) Coop Res Unit Seattle, Forest and Rangeland Ecosystem Science Center
Description 14 p.
First page 147
Last page 160
Country United States
State Nevada
Other Geospatial Great Basin