BOZEMAN — Montana fisheries biologists found fewer large trout in a stretch of the Yellowstone River that was hardest hit by a fish-killing parasite last summer.
Fish, Wildlife and Parks biologist Scott Optiz says the number of brown trout between 13 and 20 inches long was down by about 50 percent in samples taken in the Corwin Springs area and in a stretch of river through the Paradise Valley. However, there were more young brown trout, so total numbers remained about the same.
The population of large rainbow trout declined by about 30 percent in those areas.
Last August, FWP closed down 183 miles of the Yellowstone from Gardiner to Laurel after a parasite killed thousands of mostly whitefish.
Opitz says low flows and warm water last fall and increased ice on the river this winter could have contributed to the population changes.