Skip to Main Content
Global warming of salmon and trout rivers in the northwestern U.S.: Road to ruin or path through purgatory?Author(s): Daniel J. Isaak; Charles H. Luce; Dona L. Horan; Gwynne Chandler; Sherry Wollrab; David E. Nagel
Source: Transactions of the American Fisheries Society. 147: 566-587.
Publication Series: Scientific Journal (JRNL)
Station: Rocky Mountain Research Station
Download Publication (2.0 MB)
Related Research Highlights
Monitoring the impact of changing climate on western rivers and cold water species
DescriptionLarge rivers constitute small portions of drainage networks but provide important migratory habitats and fisheries for salmon and trout when and where temperatures are sufficiently cold. Management and conservation of cold‐water fishes in the current era of rapid climate change requires knowing how riverine thermal environments are evolving and the potential for detrimental biological impacts. Robust estimates of warming rates, however, are lacking due to limited long‐term temperature monitoring, so here we compile the best available multi‐decadal records and estimate trends at 391 sites in the 56,500 km river network of the northwestern U.S. Warming trends were prevalent during summer and early fall months in recent 20‐year and 40‐year periods (0.18-0.35 °C/decade during 1996-2015 and 0.14-0.27 °C/decade during 1976-2015), paralleled air temperature trends, and were mediated by discharge trends at regional and local levels. To illustrate the biological consequences of warming later this century, trend estimates were used to inform selection of river temperature scenarios and assess changes in thermal exposure of adult sockeye salmon migrating to four population areas as well as thermal habitat shifts for resident brown trout and rainbow trout populations throughout the region. Future warming of 1-3 ᵒC would increase sockeye salmon exposure by 5-16% (3-143 degree‐days) and reduce thermally suitable riverine trout habitats by 8-31% while causing their upstream shift. Effects of those changes on population persistence and fisheries are likely to be context dependent and strategic habitat restoration or adaptation strategies could ameliorate some biological impairments but effectiveness will be tempered by the size of rivers, high costs, and pervasiveness of thermal effects. Most salmon and trout rivers will continue to provide suitable habitats for the foreseeable future but it also appears inevitable that some river reaches will gradually become too warm to provide traditional habitats.
- You may send email to firstname.lastname@example.org to request a hard copy of this publication.
- (Please specify exactly which publication you are requesting and your mailing address.)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
CitationIsaak, Daniel J.; Luce, Charles H.; Horan, Dona L.; Chandler, Gwynne; Wollrab, Sherry; Nagel, David E. 2018. Global warming of salmon and trout rivers in the northwestern U.S.: Road to ruin or path through purgatory? Transactions of the American Fisheries Society. 147: 566-587.
Keywordsglobal warming, rivers, salmon, trout, migratory habitats, fisheries, management, conservation
- Enhanced incubation success for kokanee spawning in groundwater upwelling sites in a small Idaho stream
- Effects of climate change and wildfire on stream temperatures and salmonid thermal habitat in a mountain river network
- Status and distribution of chinook salmon and steelhead in the interior Columbia River basin and portions of the Klamath River basin [Chapter 12]
XML: View XML