PKD disease may be killing South Fork whitefish

A disease similar to one responsible for a fish kill last month in the Yellowstone River may be responsible for an outbreak on the South Fork of the Snake River.

Idaho Fish and Game recently received reports of sick and dead whitefish. Biologists are surveying the river to guage the extent of the kill and which fish are involved.

Scientists suspect it may be an outbreak of proliferative kidney disease, or PKD. A similar fish kill of mostly whitefish was observed on the South Fork in 2012 and was attributed to PKD.

They said the outbreak is unlikely to affect the river’s overall fish population, but could kill thousands of whitefish.

Regional Fisheries Biologist Brett High confirmed thousands of dead whitefish were visible in eddies and along the banks. Most of them were observed in the upper reaches of the river. Relatively few were seen below Burns Creek.

“We confirmed that healthy whitefish and trout are still very abundant, and only a small percentage of fish showed signs of disease,” said High.

Regional Fisheries Manager Dan Garren said the disease has been in Idaho for over 30 years. “We’ve seen similar outbreaks in the South Fork and other waters in recent years,” Garren said. “Because we monitor these fisheries so intensively, we can say with confidence that trout and Whitefish populations have continued to do very well even after we confirmed that PKD was present.”

Garren said biologists do not know for certain how organisms get transmitted from one body of water to another. But, he said fishermen and boaters can reduce the risk by carefully cleaning and drying their equipment between trips.