Just across the Continental Divide, the upper Clark Fork River suffered the steepest decline of all, going from 1,800 brown trout per mile in 2013 to a mere 82 in 2019. Over the same period, brown trout declined by 60 percent in the Ruby River below the dam (from 1,500 to 600 fish per mile) and by 50 percent in the Beaverhead River (from 2,000 to 1,000). On the most popular reach of the Big Hole near Melrose, in Fellin’s back yard, numbers plunged by 80 percent, from 1,800 fish per mile in 2014 to 400 per mile this year. On the lower Madison by Norris, brown trout numbers hit a 20-year low of 459 fish per mile this year. Sure enough, the data showed brown-trout populations plummeting across the troutiest portion of the state, with the epicenter of the decline in the storied waters that join to form the Missouri River. Soon after, I started sleuthing around to figure out if this was just a cyclical blip or something bigger. Strange Disappearance Last spring, after more than 800 whitefish, brown, and rainbow trout were found dead of mysterious causes in the Beartrap Canyon stretch of the Madison River, newspapers across the state ran stories about the disappearance of brown trout from southwest Montana’s rivers. Bob Behnke, described them as “one of the most genetically diverse vertebrates known.” Some biologists have proposed dividing brown trout into 50 unique species.
The world’s foremost wild-trout expert, the late Dr.
Native to Europe, North Africa, and West Asia, brown trout have expanded across the planet, exhibiting a wide range of evolutionary adaptations that allow them to thrive in streams, lakes, and even the ocean, where their life cycle is similar to a salmon’s. Then there’s the fact that they adapt well to new environments-just look how far and wide they’ve spread in Montana since they were introduced to the Madison River in 1889.
0 kommentar(er)
