Role of climate and invasive species in structuring trout distributions in the interior Columbia River Basin, USA

• Published in: Canadian journal of fisheries and aquatic sciences Vol. 68; no. 6; pp. 988 - 1008
• Main Authors: WENGER, Seth J, ISAAK, Daniel J, CHANDLER, Gwynne L, DUNHAM, Jason B, FAUSCH, Kurt D, LUCE, Charles H, NEVILLE, Helen M, RIEMAN, Bruce E, YOUNG, Michael K, NAGEL, David E, HORAN, Dona L
• Format: Journal Article
• Language: English
• Published: Ottawa, ON NRC Research Press 01.06.2011; National Research Council of Canada; Canadian Science Publishing NRC Research Press
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Climate change; Climate effects; Climatic changes; Distribution; Environmental aspects; Exploitation and management of natural biological resources (hunting, fishing and exploited populations survey, etc.); Freshwater; Fundamental and applied biological sciences. Psychology; Geomorphology; Global warming; Indigenous species; Influence; Invasive species; Land use; Nonnative species; Oncorhynchus clarkii; River basins; Rivers; Salmon; Salvelinus confluentus; Salvelinus fontinalis; Trout; United States; Vertebrates: general zoology, morphology, phylogeny, systematics, cytogenetics, geographical distribution; United States; North America; America; Columbia River; Columbia Basin; USA, Columbia R. basin; Salmonidae; Warming; Climate; Temperature; Geomorphology; Hydraulics; Trout; Columbia River basin; Land use; Oncorhynchus clarki; Freshwater environment; Logistic regression; Vertebrata; Invasive species; Cold water; Salvelinus fontinalis; Pisces; Watershed; Autochthonous; Salvelinus alpinus; Native species
• ISSN: 0706-652X; 1205-7533
• DOI: 10.1139/f2011-034

Recent and projected climate warming trends have prompted interest in impacts on coldwater fishes. We examined the role of climate (temperature and flow regime) relative to geomorphology and land use in determining the observed distributions of three trout species in the interior Columbia River Basin, USA. We considered two native species, cutthroat trout ( Oncorhynchus clarkii ) and bull trout ( Salvelinus confluentus ), as well as nonnative brook trout ( Salvelinus fontinalis ). We also examined the response of the native species to the presence of brook trout. Analyses were conducted using multilevel logistic regression applied to a geographically broad database of 4165 fish surveys. The results indicated that bull trout distributions were strongly related to climatic factors, and more weakly related to the presence of brook trout and geomorphic variables. Cutthroat trout distributions were weakly related to climate but strongly related to the presence of brook trout. Brook trout distributions were related to both climate and geomorphic variables, including proximity to unconfined valley bottoms. We conclude that brook trout and bull trout are likely to be adversely affected by climate warming, whereas cutthroat trout may be less sensitive. The results illustrate the importance of considering species interactions and flow regime alongside temperature in understanding climate effects on fish.