Montana’s Famed Trout Under Threat as Drought Intensifies

[Pat Stout]

Montana’s Famed Trout Under Threat as Drought Intensifies
New York Times
Courtesy John Groh

The state is imposing more restrictions on fishing this year as the combination of extreme conditions, including low river levels, fish die-offs and the crush of anglers, poses long-term problems.

HELENA, Mont. — Few places in the world rival Montana’s fly fishing, and the state’s cold, clear mountain streams are renowned for their large populations of trout, especially the rainbow and brown. But this is a drought year, and a confluence of extreme conditions now threatens the state’s legendary waters. Higher temperatures early in the year, worryingly low river levels, fish die-offs and pressure from the crush of anglers yearning to recapture a year lost to the pandemic have swirled into a growing crisis.

This week the state announced a slate of new restrictions, including outright closures, for some of the top trout streams. And a new coalition of businesses, fly fishing guides and environmentalists warned that the severe drought may not be a temporary problem and that the state’s fisheries could be nearing collapse. The coalition, which includes Orvis, the fly fishing company, and the clothing manufacturer Patagonia, sent Gov. Greg Gianforte a letter Wednesday seeking the creation of a task force to address the decline of the fisheries. “Between early season fish kills, unnaturally warm water temperatures and low trout numbers, it’s an all hands on deck moment,” said John Arnold, owner of Headhunters Fly Shop in Craig, along the Missouri River, one of the state’s premier fisheries.

The coalition said that the conditions not only threatened the fisheries, but also would be devastating for businesses. “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 group stated in its letter.
“This is a really unique, ecologically speaking, part of the world,” said Guy Alsentzer, the executive director of Upper Missouri Waterkeeper. “These rivers are really hurting and they need cold, clean water.” The crisis is occurring as the state was just beginning to recover from the pandemic, with tourists and fishing enthusiasts returning in large numbers. Anglers of all kinds spend nearly $500 million a year in Montana, according to the American Sportfishing Association. In addition to low river levels and even dry sections of some small streams, dead trout have been found floating in rivers around the state, a sight that in other seasons was rare. And there has been a mysterious, steep decline in one of the most sought-after fish, brown trout, over the last several years in southwest Montana.

Trout thrive in water between 45 and 60 degrees. Temperatures in some rivers have hit the low-70s much earlier than usual. At those temperatures the fish are lethargic because there is less oxygen in the water and they quit feeding; the stress of being caught by fishers in that weakened state can kill them. Around 75 degrees can be lethal to trout.

Montana’s rivers and streams are wild trout fisheries, which means that unlike in most states, rivers there are not stocked with hatchery-reared trout. If populations crash, the state’s wild trout would have to rebound on their own, which could take years or might not happen at all.

Low flows and warm temperatures are affecting sport fishing across the West, from California to Colorado. On the Klamath River in Northern California, the Iron Gate Fish Hatchery could not, for the first time in its 55-year history, stock the river with young hatchery-reared salmon and steelhead because extremely low flows and warmer water temperatures have increased infections from C. shasta, a parasite.

Utah has doubled the allowable limit for fishers because low water levels are expected to kill many fish in the streams. In Colorado, state officials asked people not to fish a 120-mile-long stretch of the Colorado River in the north-central region because of low river levels and warmer water.

“The water temperatures have been above 70 degrees for multiple days in a row,” said Travis Duncan, a spokesman for Colorado Parks and Wildlife. “And there is a potential for more closures as we get further along in the season.”
On Tuesday, the Montana Department of Fish, Wildlife and Parks imposed “hoot owl” restrictions on the Missouri River, one of the most popular trout fishing sites in the state, between Helena and Great Falls because of warm water temperatures. The rule bans fishing after 2 p.m. (The term “hoot owl restrictions” stems from the early days of the timber industry. Loggers work early in the mornings of late summer, when it’s cooler, because the forests are dry and that increases the risk of chain saws or other equipment sparking a fire. Loggers often heard owls during their early morning shifts.)

Yellowstone National Park announced that, beginning on Saturday, it would shut down fishing on its rivers and streams after 2 p.m. until sunrise the following day, citing water temperatures exceeding 68 degrees and extremely low river flows. “These conditions are extremely stressful and can be fatal to fish,” the park said in a news release. Although restrictions are often put in place at some point in the summer season, this year is unusual. “From what we know historically, this is unprecedented in the extent” of limits that have been imposed, said Eileen Ryce, the administrator for the state’s fisheries division.

Compounding the situation here is the decline over several years in brown trout populations in the southwestern part of the state, including the Big Hole, Ruby, Yellowstone, Madison and Beaverhead Rivers, some of the top destinations for fly fishers. This year on the Big Hole River, for example, on one of the most popular stretches, a May census found 400 brown trout per mile, down from 1,800 in 2014. The Beaverhead River has dropped to 1,000 from 2,000 brown trout per mile. And those counts were conducted early in the season, before the onset of this summer’s extreme conditions. The state is considering long-term restrictions on all of these rivers, which could include release of all brown trout or shutting down fishing in some places.

What, precisely, is causing the decline over such a large regional area of the Upper Missouri River Watershed is stumping experts, especially since brown trout are traditionally a hardy, resilient species, able to handle warmer temperatures. Many attribute the decreases, at least in part, to shifting river conditions caused by climate change.

Oddly enough, an unintended benefit of the raging wildfires in the West has been the smoky skies, which may be keeping the rivers from getting even warmer by reducing the amount of direct sunlight.

Meanwhile, on the Beaverhead and Bitterroot Rivers, anglers have reported seeing fish with large lesions whose cause is still unknown.

Beyond hoot owl limits, those who fish have been asked to rapidly land their catch and carefully and quickly release them, to minimize the stress of handling and reduce the potential for killing them.

Other factors threatening Montana’s trout include agricultural changes. Ranchers used to primarily flood irrigate their fields, which returned about half the water to the river system. Now many use pivot irrigation systems, which are far more efficient and use nearly all of the water. “We may have altered groundwater so much that brown trout haven’t been able to adapt,” said Patrick Byorth, the director of Trout Unlimited’s water project for Montana. The group is a nonprofit focused on fisheries.

Water pollution also adds to the problem. Increasing construction near resort areas along the Gallatin River near Yellowstone National Park, for instance, has contributed, with storm water runoff and septic systems sending phosphorus and nitrogen into the Gallatin River, causing algae blooms. The bloom is exacerbated by warmer temperatures and lower flows.

One big question that can’t be answered is whether this is just a bad year, or a part of a more permanent change in the climate, a long-term aridification of the West.

Mr. Arnold, the fly-fishing guide who has worked on the Missouri River for decades, said the decline in trout populations has been occurring over a longer span of time than just this year. “My top guides could put 60 fish in the boat in a day,” he said. “Now half of that would be considered a good day.” “It’s all climate-change related,” Mr. Arnold said. Twenty years ago, nobody fished in November and March because it was so cold, he recalled. Now they do. “It’s starting to feel like a downward spiral.”

A version of this article appears in print on July 24, 2021, Section A, Page 9 of the New York edition with the headline: Crisis in the Clear, Deep Pools of Montana.

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[Pat Stout]

This is a timely article to post as it elucidates the spectrum of adverse conditions that our watersheds must endure. That is not to say that these adverse effects can be generalized for all watersheds as each are different, from topography to longitude/latitude to altitude to seasonal weather and so on. And, to say it is “all climate change related” is more than a little disingenuous as it excludes other drivers of poor water quality.

As for the Snake River, the region is abnormally dry this year, although we are seeing some seasonal rains and the pastures look good. The flows are around 17-18 cfs which indicates a wetter riparian zone. In a drought year, you might see it as low as 12-13 cfs. Of course, the writers act as if this is the first drought in history when in fact, this area has had one in 2002 and 2012, the latter exceptionally severe. The 2012 drought has been followed by years of wetter than normal years until 2020-2021.

The greatest threat to the Snake River below Merritt Reservoir is the operational hydrology. The building of the Merritt dam and its structural characteristics resulted in an exceptional wild trout fishery, what with sediment reduction and enhanced thermal regime. Those same attributes can be adversely altered depending on how the dam is run. Remember, this is an irrigation project. Period. For the first 40 years or so, it was run like a dam, largely irrespective of aquatic life in the lake and river or even neighbors. With Rod Imm assuming the manager position and the negative effects of the 2002 drought, attitudes began to change for the better. And the renewal of the dam lease in 2006 fostered even better discussion. With this lease, the Ainsworth irrigation District was restricted to around 85,000 acre feet. Prior to that, it was unlimited and had, in one instance used upwards of 94,000 acre feet. Some of the “enhancements’ that were negotiated were as follows.

Ramp Rates:
No formal regulations existed on how fast the AID could ramp up or ramp down water releases from the dam. The fish kill in 2000 was due to the AID allowing a cattle crossing during high summer temperatures around 100F +/-, dropping the water well over 200 cfs and 3 hours later, dumping the same amount in one turn of the wheel. This was associated with high thermal temps from the lake water and an ongoing blue algae blue killing large numbers of fish. Now, the AID has established a ramp rate of 50 cfs, up or down, over 6 hours. This is also highly beneficial for maintaining the integrity of the banks and minimizing slumping.

Timing of Releases:
If one studies each water year after the dam was built, you will notice the 1st 45 years were consistently inconsistent on flow releases. In particular, the spring and fall flows were helter-skelter. Or like in the fall, the water was turned off way more than on. The timing was potentially damaging as it coincided with rainbow (spring) and brown (fall) spawns. In 2012, the Bureau of Reclamation turned off the dam in late March for a week to do an inspection. An inspection that had been scheduled in September of 2011 and forgotten. The damage, particularly above the falls was irreparable in what already is limited spawning. Now, during March-April-May, the AID will not go below 100 cfs. In the fall, the flows from the dam will start on October 15th. A caveat here, is that these are guidelines during normal dam operations. In cases of adverse events or emergencies, the AID has to comply with the federal rules they work under. After all, it is only an irrigation project.

Adjustment of Summer Releases:
For many years, but not consistently, the summer dam release was ~ 50 cfs. It was apparently based on some Habitat Suitability Index (HIS) that nobody knew where to find. By the Memorandum of Agreement between the NGPC, AID and Reclamation, summer releases were decreased from 4000 acre ft to 2000 acre ft. A political action, but with no scientific basis. You must understand that even though we own the land below Merritt dam, we have no legal standing when it comes to the water. Based on scientific data, the SRPG/SFSC agreed to release the summer flow (total 20 days) for consistent fall flows. This happened in 2015. It was followed by wildly speculative claims of harm and devastation that are still embraced today. Once the irrigation begins in earnest, usually late June or early July, the dam release is shut off. With exceptions like 2018, where Noah-like precipitation occurred. While 17-18 cfs is low, it is sufficient for trout. However, the low flows come with a highly favorable diel thermal regime (DTR), while flow from the dam in June, July, August and even September have a greatly diminished DTR. With dam flows, we have documented maximum temps in the 75-80F range and DTRs so small that this river may stay in the 69-70-71 temperature around the clock. At spring flows, the DTR may vary as much as 16F over 24 hours. Why? Because the area is semi-arid and has cool nights and the river temps are influenced, up to 72%, by atmospheric condition, not so much the springs.

[Pat Stout]

This is the Delores River below McPhee Reservoir, a stretch that I have enjoyed fishing in years past. It has gone from 70 cfs to 7-9 cfs in the drought. The stretch below the dam will potentially be a total mortality. Not just trout, but sculpin, native suckers and chubs. With many of the western waters limited or off limits. We are getting a few more guests from Wyoming and Montana.

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