Trout Seek Out Thermal Refuges in Streams To Cope With Hot Weather

As climate change is making heat waves more common around the world, including here in Connecticut, understanding this question is becoming more important. Cold-water fish like trout have a strategy for surviving extreme heat—moving into thermal refuges. Thermal refuges are areas in a river where colder water discharges into warmer stream water, creating a "cold-water patch." This can be caused by groundwater seeping into the stream at certain locations or even when a smaller, well-shaded stream joins a larger river, creating a plume of colder water.