The North Platte River in southern Wyoming has recently been low enough for toddlers to easily cross and thick olive-green algae mats to grow in lazy streams.
Just two years ago, workers piled up sandbags to protect their homes and fishing sheds from the raging brown floods. This is the highest ever.
Both scenes differ from the proper pictures of famous trout fishing destinations. An angler slides downstream on a drift boat and throws a fly lure in the hope of landing a large brown and rainbow trout in the shadow of Medicine Bow Mountain.
However, in recent years, in the turmoil of climate change, both torrents and trickles have plagued the famous trout streams in the western United States, making the region hotter and drier, and fueling severe weather events. Intense heat waves and prolonged droughts have raised water temperatures in some states, jeopardizing fish species.
In the Rocky Mountains, attention is focused on trout fishing, which accounts for the majority of both the US $ 1 billion annual fly fishing industry and the region’s $ 100 billion annual outdoor recreation industry.
“The extreme seems to be the extreme,” said Tom Wiersema, who has been fishing upstream of the North Platte as a guide and trout enthusiast for nearly half a century.
For several years, Wiersema was able to float part of a river about 10 miles (16 km) north of the Colorado Line throughout the summer. This year, Wiersema didn’t mind floating the stretch from late June so that he didn’t have to drag the boat over the wet rocks covered with algae.
“That’s the river at that point. It’s a round, slippery bowling ball,” he said.
In nearby Saratoga, a jumping trout with a population of 1,600 adorns the light posts and city hall signs. North Platte roars past a public hot spring called the Hobo Pool, and trout fishing and autumn elk hunting are big businesses.
Phil McGrath, owner of Hack’s Tackle & Outfitters along the river, said the low flow did not adversely affect the business of guided fishing trips on driftboats departing from the town’s deep sea. He said the fishing was great.
“I want to go comfortably with the little guys in the afternoon,” he urged a recent group of customers asking where they could get the line wet before the next morning’s guided trip.
If the temperature is 85 degrees Celsius (29 degrees Celsius), as high as the day, and the water temperature is not delayed enough, that is the basic trout fishing ethics.
Problem: Water above 68 ° C (20 ° C) can be rough on trout caught in sports rather than supper and can be released to fight another day. Low waters warm up rapidly during hot weather, and hot water carries less oxygen, stresses the fish, and can survive catch-and-release fishing, especially if the angler takes less than a few minutes to gently release the fish. The sex is low.
Temperatures soared in the mid-1980s, and after this summer, Yellowstone National Park stopped fishing on rivers and rivers for a month from 2:00 pm to sunrise. Montana has imposed similar “owl” restrictions on the legendary trout river, including Madison, which flows out of Yellowstone. This is because owls can be active early in the morning.
Low and warm water urged Colorado to impose voluntary fishing restrictions upstream of the Colorado River for some time — even when flash floods and landslide spasms choked the river and closed Interstate 70. ..
In rivers such as the upper North Platte, which flows north from Colorado, low water not only flows warmly, but also slowly clears and grows algae. Algae mats can collect insects while providing shade from trout and cover from predators, but before becoming a local representative of fishing-oriented protection, as it is also a symptom of warm and stressful conditions. Jeff Streeter, who guided the top of North Platte to, said Group Trout Unlimited.
“I don’t know where that threshold is. I’m a little worried,” he said.
Like Colorado, Idaho and Wyoming did not order anglers to stop fishing. Idaho officials have determined that such an order is unlikely to bring many benefits.
David Zaft, Wyoming’s fish management coordinator, said Wyoming’s rivers would be difficult to monitor to force closures, as temperatures fluctuate significantly from shallow to pit throughout the day. ..
Droughts and heat under the skies polluted by wildfire smoke also have different effects on each of the larger rivers in the west. Many are blocked, with North Platte launching a 100-mile (160-kilometer-wide), 180-degree loop through a series of reservoirs that serve farmers and ranchers in Wyoming and Nebraska. ..
Most predictable cold currents from the Semino Reservoir make the North Platte’s “Miracle Miles” section just upstream of the Pathfinder Reservoir a trout fishing paradise.
However, upstream of Semino, the river is exposed to natural fluctuations. In trout fishing, mountain snow is at least as important as the warm moon rain pattern, but expectations based on decades of snow records have been questioned.
“Things have changed too rapidly. We are in the process of understanding how this climate affects our snow, spills and temperatures. We are still asking those questions. I don’t think I can really answer. “
Records dating back to 1904 support Wiersema’s allegations about the extremes of the upper North Platte.
In 2011, high flow broke all previous monthly averages for June and July. The flood in 2019 was the worst, by more than 20% compared to the runner-up in 1923.
However, since 2000, the river has recorded August, when it has the least flow in August. They included the sixth lowest in 2012, the twelfth lowest in 2018, and the third lowest in 2020.
August 2021 is approaching a minimum of 10 on average. The snow in the mountains last winter and spring was almost normal, but the ground has been so dry since last year that much of this year’s snowmelt has soaked in without contributing to the flow.
This pattern is becoming more common in the west, said David Gochis, a hydrometeorologist at the American Center for Atmospheric Research, based in Boulder, Colorado.
“Even in the average year of snowfall, most of the snowfall fills the soil and then fills the stream, whereas most of the snowfall is landscape water (shallow aquifers, soil). Just replenish it, “Gochissu said.
Still, heavy rains may not all be bad for the river trout, given the massive wildfires of 2020 that burned the vast area just east of the upper North Platte in the Medicine Bow National Forest.
In July, a landslide in a burned area just 50 miles (80 km) away in Colorado killed three people and blocked the Cash La Poodle River with silt. That’s not happening in North Platte, but the hottest wildfire season in the west is a threat to trout populations, said Helenneville, senior scientist at Trout Unlimited.
“Fire is, of course, a natural process, well adapted to Western trout and salmon, but the scale and intensity of recent fires may exceed the resilience of nature in some cases.” Neville said in an email.
According to Neville, climate change is of particular concern to Cutthroat trout. Cutthroat trout, unlike brown, rainbow and brook trout, grow naturally in the Rocky Mountains.
What lies ahead in North Platte depends on future patterns of rain, snow and snowmelt, not to mention ever-increasing human water demand. McGrath, a fly-fishing guide and owner of a tackle store, had no doubt that climate change was at work and that it was artificial. But he didn’t seem to lose sleep with it.
“If the world keeps getting warmer, will trout fishing get worse? Yes, of course. Trout are cold-water animals, right?” McGrath said. number. “
Follow MeadGruver on https://twitter.com/meadgruver
Follow the Associated Press’s full drought coverage: https: //apnews.com/hub/droughts.