Rocky Mountain whitefish are dying in Eastern Idaho rivers and the Idaho Fish and Game Department is looking for help from river users.
Over the past few weeks, IDFG has documented dead mountain whitefish on the South Fork and mainstem Snake River, and has received similar reports of dead whitefish on the Teton and North Fork Salmon Rivers. The cause of the kill remains a mystery.
“It’s particularly interesting in that whatever is going on is affecting only whitefish, and not trout” said Regional Fisheries Manager Dan Garre. “It also appears to be affecting the smaller (younger) fish, generally those less than 10 inches.”
IDFG has sent numerous samples of dead or dying whitefish to the Eagle Fish Health Lab for analysis, and hopes to have results of those tests in the near future.
“If you see dead whitefish around the region, it would be helpful if you could let IDFG know.,” Garren said. “At this point, there have been no documented kills in the Henrys Fork, though it is possible that it may be happening there as well.”
Fish and Game has not documented any deaths of whitefish over 12 inches, and no reports of kills of other species.
IDFG is interested in obtaining additional information on the distribution of dead fish, and other species that may be affected by the kill. Anglers are asked to keep an eye out for additional dead fish, and to report their findings to IDFG at 208-525-7290.