by Natasha Lasky, ODP Staff Writer

Rivers and lakes across Northwestern states — from Yellowstone to Montana — have lost most of their trout, due to extreme drought conditions. Because of this, state authorities have implemented a variety of restrictions to preserve their dwindling trout populations, leaving recreational fly fishers in the lurch. 

Why This Matters: Fishing is a major part of the economy in Montana and Yellowstone, places that thrive on outdoor recreation. Anglers of all kinds spend nearly $500 million a year in Montana, according to the American Sportfishing Association. A new coalition of businesses, fly fishing guides and environmentalists wrote in a letter: “If water quality in our rivers continues to decline, and our rivers themselves dry up, these negative changes will also tank our state’s robust outdoor economy that directly depends on upon vibrant cold water fisheries.”

The drought has also affected sport fishing in California and Colorado as well:

• In Northern California, the Iron Gate Fish Hatchery could not, for the first time in its 55 years of operation, stock the river with young salmon because low flows and warmer water temperatures have increased parasite infections. 
• Colorado has closed off a 120-mile-long stretch of the Colorado River for fishing in the north-central region for similar reasons. 

Big Fish In Increasingly Small Ponds: Trout like to live in water between 45 and 60 degrees Farenheit, but due to warming temperatures, there has been less water in rivers and these waters have warmed to the low 70s. At higher temperatures, the trout become sluggish because there is less oxygen in the water and they stop feeding–if the temperature passes 75 degrees, they’re at risk of death. These dangerous conditions have been exacerbated by water pollution, which has caused algae blooms that prevent trout from feeding and breathing effectively. 

Trout have been dying en masse, their corpses floating in rivers around Montana. The numbers of brown trout look particularly dismal;  this year on the Big Hole River, for example, on a particularly popular fishing area, a May census found 400 brown trout per mile, down from 1,800 in 2014. Meanwhile, trout in the Beaverhead River has dropped to 1,000 from 2,000 per mile. And this data were collected before the summer, when extreme heat and dryness set in.

In addition, Yellowstone National Park announced that it would shut down fishing on its rivers and streams after 2 p.m. Saturday until sunrise the following day, as a result of 68-degree water temperatures and extremely low river flows.

There is an odd source of hope, in that the wildfires on the West coast have emitted enough smoke into the atmosphere that it has blocked the sun from shining on the rivers, preventing them from warming further. Though this may not be enough to save struggling trout.

All in all,  the situation is looking dire this summer. “Between early season fish kills, unnaturally warm water temperatures and low trout numbers, it’s an all hands on deck moment,” John Arnold, owner of Headhunters Fly Shop in Montana told the New York Times.