Direct and Indirect Effects of Climate Change on Washington Salmon: Ecological Adaptations and Management Strategies Pete Bisson USDA Forest Service PNW Research Station Washington Climate Change Impacts Assessment Conference

Aquatic organisms are the most imperiled animals in North America

Source: Precious Heritage (2000) © TNC, NatureServe Proportion of species at risk by plant and animal group

 Water temperature  Altered hydrologic regime  Indirect effects

Lethal temperatures Predicted annual increase o F o F o F

Migration timing Copyright 2008 by The Nature Conservancy and World Wildlife Fund, Inc. All Rights Reserved:

Incubation period

Altered hydrologic regime

Shrinking drainage network

Projected losses of salmon and trout habitat from U.S. streams O’Neal (2002) /effects_of_global_warming_on_trout_and_salmon.pdf

Weather extremes Reproductive losses Direct mortality Unfavorable habitat effects

Indirect/incidental consequences Increased fire frequency and severity

Montana Fish, Wildlife & Parks Invasive species

Competing water demands

Winning strategiesLosing strategies Habitat generalistHabitat specialist Abbreviated time in fresh waterExtended freshwater rearing High stray rateLow stray rate Brief temp. exposureExtended temp. exposure Spring spawningFall spawning Lower risk Higher risk Cutthroat troutChum salmon Pink salmon Fall Chinook Winter steelhead Sockeye salmon Coho salmon Spring Chinook Summer steelhead

What can we do?  Minimize increases in water temperature by maintaining well shaded riparian areas  Maintain forests that retain snow water and promote fog drip, and lessen the “rain on snow” effect associated with large forest openings  Disconnect road drainage from the stream network to soften discharge peaks during intense storms  Ensure that fish have access to seasonal habitats, e.g., off-channel or cool water areas  Protect springs and groundwater seeps from excessive water appropriation

Thanks to: PNW Research Station Rocky Mountain Research Station NW Power and Conservation Council University of Washington