Coldwater Fishing in a Warming Climate

Each summer, millions of people in the Intermountain West make a sandwich or two, throw fishing gear in the car and head to nearby rivers and lakes to enjoy time on the water. But for anglers seeking cold-water species like trout, recent climate trends are making a good catch more difficult to come by. 

Warmer than average temperatures are shifting the spring runoff cycle earlier in the year, affecting conditions for cold-water fish species and their habitat, according the Chase Lambourn, research associate of the Institute of Outdoor Recreation and Tourism.

“Air and water temperatures in the Intermountain West have gotten warmer,” he said. “Higher temperatures mean an earlier springtime runoff, which is happening two weeks earlier than it did in the 1980s.”

This shift leaves less water in streams and rivers during the hottest parts of the year, and average summer river flows at lower levels than they were just decades ago. These changes are shrinking habitats and creating stressful conditions for prized cold-water species. 

Researchers from Utah State University’s Institute of Outdoor Recreation and Tourism recently completed research to better understand how shifting spring runoff is affecting angling in the Yellowstone River watershed. Through in-depth interviews with outfitters, guides and fisheries managers working within the watershed, they documented some of the impacts from shifting runoff times – and the adaptations anglers are making in response. Experienced anglers report they’ve seen runoff occurring earlier in the year, with shorter, more intense durations. Springtime runoff is more variable from year to year, they say, and they’ve experienced a variety of associated challenges – such as more uncertainty about river and fishing conditions.

But people are adapting to the changes to preserve the health of the region’s economy and the Yellowstone River watershed, said Lambourn. When river flows get low, and temperatures get above 70° F, outfitters and guides suggested perfecting your catch-and-release practices to ensure that the fish live to fight another day. This includes reducing fight times, minimizing handling and reducing the time fish spend out of water. 

During the hottest times of the day and year, they suggest chasing the colder water – getting out in the early morning or finding places where the water is cooler. When water conditions for trout get difficult, but you can’t let a beautiful summer day pass by, they suggest targeting warm water species such as smallmouth bass and carp. Carp actually provide anglers with an exciting and challenging fly-fishing experience, similar to chasing bonefish in the tropics, they say.

Climate researchers project that current trends in air and water temperature will continue to warm. To ensure the protection of quality fisheries and fishing experiences, anglers will need to continue adapting. By using these suggestions, it’s possible to reduce stress on prized cold-water fish species and still have the chance to be out on the water during the hottest parts of summer.

The Institute of Outdoor Recreation and Tourism (IORT) conducts research, outreach and teaching focused on outdoor recreation and tourism management. Its work focuses on the social and economic trade-offs associated with providing outdoor recreation opportunities on public lands.