FWP conducts research on Yellowstone River
BOZEMAN, Mont. - Montana Fish, Wildlife and Parks' fisheries staff recently completed their annual spring monitoring of the Yellowstone River.
Biologists found a 50-percent decrease in large brown trout and a 30-percent decrease in rainbow trout in the Corwin Springs and Paradise Valley areas, which were hit by a fish-killing parasite last August.
The river saw an increase in small trout. The total number of trout in the river remained about the same.
FWP spokeswoman Andrea Jones told NBC Montana the fluctuation in population numbers can be explained by a multitude of factors, including low flows and warm water last fall.
Jones is encouraged by this spring's runoff conditions, which look different than last year's.
"With higher flows there's more water for (the fish) to be less stressed," Jones said. "They're less likely to become infected, because they're stronger -- they've seen this before."
Last August FWP closed 183 miles of the Yellowstone from Gardiner to Laurel after a parasite killed thousands of fish, mostly whitefish.