Climate Change Causing Evolutionary Impacts To Trout

Jul 19, 2016

Credit U.S. Forest Service

Climate change is hurting certain fish species in North American streams and lakes, according to the July issue of Fisheries Magazine.

Abigail Lynch, a research scientist with the U.S. Geological Survey, is one of the guest editors for the special issue. She said she looked at several previous scientific studies when compiling the July issue and found worrisome trends, like how prolonged droughts impact fish that are normally used to having a lot of space in their habitat.

“As a drought occurs, that habitat space shrinks. So it goes from having a mansion to being a studio apartment,” said Lynch. “As a result of that there’s increased competition between fish in that smaller space, so it makes it more difficult for them to feed, breed, and even survive.”

Lynch said climate change is already having an impact on an evolutionary level, too. For instance, warmer waters are causing rainbow trout to cross breed with cutthroat trout.

“By having this hybridization event with rainbow trout you’re losing your native species and the keystone species in many stream systems,” said Lynch.

And if you lose cutthroat trout, Lynch said, you could also lose recreation opportunities to fish for the species in the state.

“People come to Wyoming to fish for cutthroat, and if there now are no longer any cutthroat it’s not necessarily that same experience,” she said.

Lynch said it was important to release this special issue of the magazine, since the effects of climate change on fish can be difficult to observe because they are underwater.