Yellowstone: Temperatures Up to 82 degrees Kill Rainbow and Brown Trout
Water temperatures of up to 82 degrees killed hundreds of rainbow and brown trout on the Firehole River this past week as warm, dry weather continues to pummel the Greater Yellowstone ecosystem.
Officials noticed the kill after they issued a fishing advisory Friday for a number of waterways in the park, asking anglers to avoid fishing low elevation waters between noon and 6:00 p.m. The partial fishing closure is voluntary, but could become mandatory if warm conditions persist. The voluntary closure starts Saturday.
According to Yellowstone spokesman Al Nash, water temperatures in a number of waterways have exceeded 73 degrees, which can be stressful or even fatal for trout.
The fish kill in the Firehole ranged from Midway Geyser Basin downstream to Firehole Cascades. The Firehole River maintains higher temperatures than other rivers in the park because of geothermal features that heat the water.