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Tracking Thermal Stress in Salmon Streams

Posted by Sue Mauger at May 10, 2017 08:45 PM |
The Canadian Journal of Fisheries and Aquatic Sciences published our paper this month about summer temperature regimes in southcentral Alaska streams and the potential implications for Pacific salmon. With five years of data from 48 streams across the Cook Inlet watershed, it is clear that salmon are already experiencing thermal stress and that over the next 50 years, chronic and sub-lethal effects will become more likely.
Tracking Thermal Stress in Salmon Streams

Daily mean stream temperatures from 2008 to 2012 at four sites during the open-water season.

Our paper: "Summer temperature regimes in southcentral Alaska streams: watershed drivers of variation and potential implications for Pacific salmon" has just come out in the Canadian Journal of Fisheries and Aquatic Sciences. We posed some specific questions: Which streams run hot? Which streams run cold? And does that change year to year? We also considered the potential implications for different salmon species and life stages now and in the future.

A collaborative network of federal, state, tribal and community entities collected data from 2008–2012. Sue Mauger, Cook Inletkeeper's Science Director, and co-authors Rebecca Shaftel and Daniel Rinella from the University of Alaska Anchorage, and Jason Leppi with The Wilderness Society found that some streams will remain as important cold-water habitats supporting healthy salmon populations for generations to come. But some streams are warming and will continue to do so putting cold-water loving salmon under increasing stress.

Water temperature in the Deshka River, which is a large lowland tributary to the Susitna River and a large producer of Chinook salmon, reached above 76 oF in 2009. This baseline dataset will allow us to accurately assess the rate of change in our watersheds in response to a changing climate. We continue to monitor 17 streams in Cook Inlet including the Deshka River where maximum temperatures reached 76.6 oF in 2016.

Our paper concludes that targeted management strategies can increase resilience in freshwater systems as our climate warms, such as improving riparian vegetation to shade streams, restoring fish passage to provide access to cold-water refugia, and identifying sensitive areas for conservation. These strategies plus continued monitoring to provide fisheries managers with current information is our best chance for long-term viability of the region’s salmon populations. Our research and protection efforts are now guided by this stream-specific information.

We are happy to see that new regional water temperature monitoring networks have started recently in Bristol Bay, Kodiak Archipelago and in southeast Alaska.

The article is open access and available here:

You can read more about our stream temperature work here.

This 5-year synthesis would not have been possible without the contributions of Dr. Dan Rinella and Becky Shaftel with the University of Alaska Anchorage – Alaska Natural Heritage Program, Jason Leppi with The Wilderness Society, and Branden Bornemann with the Kenai Watershed Forum. Their insights, time and talents were invaluable. Special thanks to Marcus Geist, The Nature Conservancy of Alaska; Robert Ruffner, Kenai Watershed Forum; Jeff and Gay Davis, Aquatic Restoration and Research Institute, and Laura Eldred with Alaska Department of Environmental Conservation, for their assistance and feedback throughout this project.

Many agencies, organizations, Tribal entities, businesses and individuals have helped to collect temperature data since 2008, including Ryan Hutchins-Cabibi, John Kelly, Becky McNeil, Catherine Inman, and Brianne Athearn with Wasilla Soil and Water Conservation District; Chris Love with Upper Susitna Soil and Water Conservation District, Billy FitzGerald with Denali Trekking Company; Jeff Davis, Gay Davis, Nick Ettema and Megan Cookingham with Aquatic Restoration and Research Institute; Scott Wolfe with The Wildlifers; Larry and Judy Heilman in Beluga; Jessica Standifer in Tyonek; Tom Evans in Nanwalek; Tracie Merrill, Michael Opheim and Norman Opheim in Seldovia; Ken Gates and Jim Boersma with U.S. Fish and Wildlife Service; Kevyn Jalone with Lake Clark National Park; David Coray and Oliver Coray with Silver Salmon Lodge; Jan Bullock, Nick Logelin, Ted Otis, Tom Griffin, Joe Loboy, and Mike Parish with ADF&G; Laura Eldred with ADEC; John Lang, Adam Cross and Eric Johansen with U.S. Forest Service; Kate Malloy, Holly Kent, Greg Collins, Matt Kays, Cherie Northon, and Thom Eley at Anchorage Waterways Council; Megan Haserodt, Jennifer McCard and Michelle Martin at Kenai Watershed Forum; and Cook Inletkeeper staff and volunteers: Rachel Lord, Michael Sharp, Will Schlein, Tala Woodward, Liza Mitchell, Marcella Dent, Eric Grazia, Jackie McDonough, Marianne Aplin, Emilie Otis, Elsa Otis, Zach Tappan, Kelly Barber, and Greg Goforth.  In addition, Jennifer McCard, Elizabeth Jones, Jim Czarnezki, Samantha Fox, Rebecca Zulueta and Branden Bornemann with Kenai Watershed Forum provided excellent database and analysis support; and Tom Kurkowski and Nancy Fresco at Scenarios Network for Alaska Planning provided climate projection mapping and data.

The Stream Temperature Monitoring Network for Cook Inlet Salmon Streams is supported by a variety of funding sources for different sites across the basin. The overall project was made possible in part by Alaska Clean Water Action grants from Alaska Department of Environmental Conservation; U.S. Fish and Wildlife Service through the Alaska Coastal Program, Mat-Su Basin Salmon Habitat Partnership and Kenai Peninsula Fish Habitat Partnership; and with funding from Alaska Conservation Foundation, Bullitt Foundation, Wolfensohn Foundation, New-Land Foundation, True North Foundation, and Skaggs Foundation.  Generous support was also provided by Cook Inletkeeper’s members and business supporters.