Frequently Asked Questions About the Effects of Climate Change on Trout and Salmon
How will climate change affect rivers and streams?
Climate change is caused by an increase in greenhouse gas concentrations that is warming our atmosphere. As the atmosphere warms, the distribution and intensity of rainfall is predicted to cause longer droughts but also increased flooding from big storms, as well as longer and more intense wildfire seasons. Reduced snowpack, increased frequency of rain and snow, and earlier runoff of snow will mean increased winter flooding and less cold water in rivers and streams for trout and salmon throughout the year. Human demands for water will also increase in some regions, meaning less water for fish and wildlife.
How will climate change affect trout and salmon?
Trout and salmon require cold water to survive and the warming of the atmosphere will increase water temperatures, making certain sections of streams and rivers uninhabitable for trout and salmon as water temperatures increase. Most climate change models predict increases of approximately 5.4° F by the year 2050. Fish that are already stressed by poor water quality, degraded habitat, and non-native species will have a harder time as these natural disturbances increase and cause additional strain on them.
Why are trout and salmon particularly vulnerable to climate change?
Trout and salmon are naturally vulnerable to climate change because of their dependence upon cold and clean water. Most species require high quality conditions for spawning, egg survival, and rearing of young. In addition, habitats of many trout and salmon species are degraded by past land and water management and are restricted to small, fragmented habitats. These isolated populations have a harder time bouncing back from disturbances such as droughts, floods and wildfire. Because trout and salmon are sensitive to water quality and much of our landscape is already disturbed by human activity, the increased natural disturbances from climate change are likely to further reduce fish habitat where they can survive.
Are some species of trout more resilient to climate change than others?
Some species of trout, such as redband trout and Lahontan cutthroat trout, live in high desert habitats that naturally may be warmer than those habitats of other trout species. Additionally, large, interconnected populations of all species that occur in larger watersheds have access to larger and better habitats and are therefore more resistant to climate change impacts. Examples of larger, interconnected populations include Westslope cutthroat trout in the Middle Fork of the Salmon, and Bonneville cutthroat trout in the Bear River drainage. Large natural lake populations, such as Yellowstone cutthroat trout in Yellowstone Lake, also are naturally resistant, if they can survive large populations of non-native trout species.
What does Trout Unlimited think needs to be done to conserve salmon and trout through a warming climate?
Trout and salmon can survive the effects of global warming through an integrated effort to protect the best remaining fish habitats, to reconnect fish habitats by removing instream barriers and re-establishing instream flows, and to restore vital main stem river and streamside habitats. Significant efforts must be made to sustain stewardship activities by engaging young people, local communities, landowners, state and federal agencies, other conservation organizations and industry in the recovery of lands and waters where trout and salmon live.
What can Trout Unlimited members and chapters do to help local streams and rivers endure the effects of climate change?
Trout Unlimited members and chapters can work with state and local partners to identify and protect high quality habitats and sources of cold, clean water. They can identify barriers to fish movement within streams such as perched culverts or small obsolete dams, and work to remove these barriers. They also can restore entire watersheds by working with landowners and agencies to improve habitat diversity in streams and floodplains. Trout Unlimited’s Conservation Success Index  can help identify strategically important places for new restoration projects. Other stewardship activities include: working with communities to plant trees and sustain conservation and recovery efforts, and monitoring changes in fish populations and waterways. A few of the most practical and easiest steps include conserving water and energy at home and in the workplace.
What can individuals do to help protect their local streams from the impacts of climate change?
Restoring healthy riparian zones – those habitats along streams – is probably the single most important action that can be done to protect local streams from degradation caused by climate change. By working with landowners and local agencies, private citizens can replant streamside zones with native shrubs and trees that will protect stream banks during times of flood and provide increased shade to streams during hot periods. They can also identify springs, small streams and other sources of cold water that need to be protected from livestock or development.
What can municipalities do to help mitigate the effects of climate change on streams and rivers in their areas?
Municipalities can protect and restore streamside areas and floodplains from unwise development and work to restore these sensitive areas to more natural conditions. Flooding is likely to increase in the future and rivers will need access to their floodplains to reduce energy associated with high flow events. Municipalities can also help reconnect streams and rivers by removing unsafe or aging dams and replace culverts that block fish from migrating upstream. Environmental monitoring and education efforts can help identify the effects of climate change and develop a better understanding of needed actions.
What does Trout Unlimited want Congress to do about climate change and its effect on trout and salmon?
Trout Unlimited advocates that Congress aggressively fund programs that provide incentives to landowners and municipalities to protect high quality habitat, and restore water quality and watershed health. While Congress ultimately needs to facilitate the reduction in greenhouse gases, urgent action is needed now to protect existing trout and salmon populations where they still thrive, and recover the health of entire watersheds so these fish can survive the increased stresses that lie ahead. America’s Climate Security Act, S. 2191, a bipartisan bill introduced by Senators John Warner (R-VA) and Joe Lieberman (D-CT) is a strong bill because it not only provides aggressive reduction in emissions of greenhouse gases, but would invest an estimated $150 billion through the year 2030 on projects designed to enhance sustainability of fish and wildlife in the face of continuing climate change impacts.