Bozeman Daily Chronicle article: Dead fish found in Yellowstone River


State officials have found dead fish in the Yellowstone River for the first time this year and they are waiting on test results to find out whether the deaths are due to the same parasite that killed thousands of mountain whitefish in the stream a year ago.

Montana Fish, Wildlife and Parks said in a news release that staff floating from Livingston to the Grey Bear Fishing Access on Tuesday and Wednesday found a total of 76 dead mountain whitefish, one dead brown trout and two dead suckers.

Test results that could show what killed the fish won’t be available until next week, the release said, and biologists don’t know enough to determine an exact cause yet.

Travis Horton, FWP’s regional fisheries manager, said in the release that staff will keep floating the river and that he anticipates they’ll know more next week.

“Protecting the health of the river and fishery is our top priority so we’re taking every precaution,” Horton said.

The release said FWP staff will stay on the lookout for dead and dying fish upstream of Columbus. On Thursday, staff will float from Mallard’s Rest to Pine Creek, a section of the river that runs through the Paradise Valley.

That section was hardest hit by last year’s fish kill, which was caused by a microscopic parasite that can cause proliferative kidney disease. Thousands of mountain whitefish died because of the parasite, which was exacerbated by low flows and high water temperatures.

In other places where the parasite has been present, fish kills have occurred annually. State biologists were optimistic about this year because of better river conditions. Flows are higher and temperatures have stayed lower, and longer and cooler nights are keeping temperatures down.

The release said those conditions “could result in a much different scenario and outcome compared to last year’s fish kill.”

FWP encourages anyone who sees dead or dying fish to call Travis Horton at 994-3155.

Full article link here.