Laura Lundquist

(Missoula Current) More fishermen are coming to Montana for the experience of reeling in a mountain trout. But climate change is steadily warming the rivers, hurting not only the trout but eventually the economies that depend on angling tourists, according to a recent study.

A U.S. Geological Service study used almost 35 years of data to show that not only are Montana’s trout streams warming, but also that climate change is causing a change in fishing habits that could affect local and regional economies. The paper was published a few weeks ago in the journal Science Advances.

Local anglers have witnessed changes on the rivers over the past few decades. Drought-ravaged rivers are dropping lower during the summer, and rising water temperatures have forced Montana Fish, Wildlife & Parks to make afternoon fishing closures, known as hoot-owl restrictions, almost an annual event to try to protect trout. At the same time, rivers and access sites have gotten more crowded as more anglers try to squeeze their boats onto the water.

For example, during last summer’s heat, large numbers of fishermen flocked to the Blackfoot River in August because most other rivers had hoot-owl restrictions while the Blackfoot stayed colder due to having had slightly more snow. That put a lot of pressure on the river and its trout, and took money away from communities in places like the Big Hole River valley.

It seems clear that it all has an effect, and this study shows some of what’s going on and its implications for the future.

"Trout fisheries have enormous cultural, economic and ecological importance in Montana and worldwide, yet even Montana’s resilient trout fisheries could be vulnerable to future climate change," said USGS scientist Timothy Cline, the study’s lead author in a release.

The USGS has collected decades worth of environmental data, including air and water temperature and stream flow for many of Montana’s legendary mountain rivers, including the Bitterroot, Clark Fork, Blackfoot and Flathead rivers. Not surprisingly, the data show that several extreme droughts reduced streamflows and increased water temperatures, causing stressful conditions for trout and numerous fishing site closures in Montana.

Trout, especially native species such as westslope cutthroat and bull trout, need cold water and start to suffer at water temperatures above about 64 degrees Fahrenheit. Using climate models, the analysis found 17% of Montana’s cold-water streams will warm within 20 years to the point that they won’t support trout. That percentage will double by 2080, affecting the Bitterroot, Big Hole, lower Blackfoot and upper Clark Fork rivers.

When that information is combined with FWP’s biennial surveys of licensed fishermen between 1983 and 2017, it showed the economic cost of climate change.

The FWP data show that a majority of both resident and nonresident anglers prefer to chase after cold-water fish. Out of the $1 billion a year spent on fishing in Montana, cold-water fisheries account for more than $700,000. Resident anglers used to spend the most, but that changed in about 2008 when more nonresidents started coming in. In recent years, overall fishing pressure was four times higher in cold-water sections than in adjacent cool-water sections and was 10 times higher for nonresident anglers.

That kind of pressure isn’t as obvious if people are spread out. But loss of some fisheries in the future means more people, especially nonresidents, will cluster on rivers like the Missouri, which has more water and stays colder due to water releases from Holter and Hauser dams. They’ll take their money with them, or eventually, they might not come at all.

The continued loss of suitable trout habitat could test the resiliency of the state’s fishing economy in coming decades. The pandemic, too recent to be reflected in the data, caused a surge in interest that offset the influence of the current drought. But over time, Montana could lose almost $200 million per year in angling revenue, or about 30% of its current trout fishing economy, according to the study.

“The effect on residents is different than on nonresidents. If I lived on the Bitterroot and it was closed, I just might not fish for a while. But if I’m coming in from Virginia, I’ll go where I can fish like the Missouri,” said Missoula FWP fisheries biologist David Schmetterling, co-author on the study. “People are going to come to Montana, whether we have drought or fires, and until recently, there was no net economic impact. But anglers go where there’s no closures or restrictions or drought isn’t affecting things, and that’s going to disproportionately affect small communities.”

The study concluded that cold-water fisheries and some of that revenue could be saved by carefully managing river systems and the people who use them, although managing people is usually difficult, especially as numbers grow. However, for the rivers, the scientists suggest restoring river floodplains and stream channels and finding ways to keep more water in the streams.

“Coordinated and multifaceted water management plans and policies that consider trade-offs among multiple ecological, social, and economic goals would help to improve system resiliency. In some cases, incentivizing water users to maintain in-stream flows may provide cold-water to sustain socioeconomically important trout fisheries, especially during periods of drought,” the study said.

FWP already owns instream water rights that could help maintain some of that resiliency by keeping water in the rivers. However, politics has recently gotten in the way.

Last year, the Gianforte administration angered some fishing enthusiasts when FWP refused to enforce its water rights on the Smith and Shields rivers in central Montana.

This July, at the direction of the governor, FWP published a protocol that biologists would use to decide when it could enforce its water rights to maintain sufficient streamflow. The governor said biologists should be able to prove that making a water-rights call would produce a benefit for fish, something they’ve never had to do in the past and which would be difficult to prove.

The new protocol requires FWP field staff to make a formal recommendation and provide reasoning for making a call to the FWP director. This year, as the drought continued to persist in central Montana, FWP did make calls on the Smith and Shields rivers, along with a few others.

Former Trout Unlimited executive director Bruce Farling, along with 21 former Montana fisheries biologists, wrote letters last year to the governor and FWP with their concerns. As rivers face a tough future, those water rights are even more important to fish and Montana’s fishing economy, and by law, FWP could lose the rights if they don't use them.

After reviewing FWP’s new protocol a few months ago, they were a little less concerned. But since the protocol was developed without public input, it still has inconsistencies, Farling said.

“It’s not that bad. The three hydrologists who worked on it put together something that was largely what they’d already been doing - just flushed out the details of how they made decisions. Except there are a bunch of new twists and inconsistencies. Like in Region 1 where we have cutthroat, native fish aren’t a priority to make a call while Region 3 prioritizes native fisheries,” Farling said.

After continually getting no response from FWP leadership this spring, Farling finally got an invitation from one of the hydrologists on Monday to meet.

“We’re going to be able to get some answers about the shortcomings we see and learn what they did this year,” Farling said. “The thing that bugs me the most about it is we didn’t know why this came up. Ag groups weren’t asking for this. No other water rights owners have to do this. What was so broken, so problematic, that we had to stop the department from making a call last year and tell them to do things differently now? We never got an answer.”

A future USGS study may give biologists some of the proof they need to show that making a water rights call would benefit fish. Schmetterling said the same group of scientists that did the economics study are researching the connection between the amount of water in Montana streams and trout production. The results should come out in a few years.

“We want to build an early warning system. If we can predict the amount of water that some of these basins are getting, then we could predict not just the severity of drought but also how it manifests itself to trout production,” Schmetterling said. “Whether you’re talking about irrigators or any kind of water user, especially in Montana, people want to do what’s right for fish and wildlife and it’s important for us to demonstrate water’s value. It’s incumbent on us to show what effects it would have if it’s there or it’s not there.”

Contact Laura Lundquist at lundquist@missoulacurrent.com.

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