Native Fisheries
2:11 pm
Tue July 16, 2013

Warming water posing a threat to native trout

Bull Trout.
Bull Trout.
Credit Joel Sartore/ National Geographic & Wade Fredenberg/ USFWS / USFWS

Scientists are studying the effects of global climate change from the peaks to the valley floors in Glacier Park.

They’re also looking in the water.

Fisheries Ecologist Clint Muhlfeld with the US Geological Survey said native west slope cutthroat and bull trout are adaptable, they’ve been adapting to environmental changes for thousands of years.’

“However, with existing stressors like invasive species and habitat loss, those things pose, certainly, some challenges to native fish, and climate warming is likely to exacerbate those existing stressors,” Muhlfeld said a lot of those stressors are human impacts like dam construction.

Muhlfeld paints a picture of the ecosystem looking back over weather data for western Montana from the past hundred years. He said they’re seeing a three-fold-increase in the number of hot days over the summer, and a loss of what adds up to about one month of cold days in the winter. He said local temperatures track global trends, but are increasing two to three times faster.

Bull trout and west slope cutthroat trout are cold water dependent species, water that’s below 55 degrees Fahrenheit. Muhlfeld said a lot of the management focus now is trying to preserve the biodiversity that remains.

“It’s really Montana’s true natural heritage, Montana’s true natives, and they represent a healthy ecosystem,” Muhlfeld said.

Plans to deal with habitat loss, hybridization, and invasive fish are among the tools Muhlfeld said managers have to help the species continue to adapt and evolve, or else go extinct.