A recent fish kill on the Yellowstone River led to a closure of the waterway. On Friday, Aug 19th, Montana Fish, Wildlife and Parks (FWP) implemented an immediate closure of all water-based recreation (fishing, wading, floating, tubing, boating, etc.) on the Yellowstone River and its tributaries from Yellowstone National Park’s northern boundary at Gardiner to the Highway 212 bridge in Laurel.
FWP took action in response to an unprecedented fish kill on the Yellowstone. During the first week of the event, MFWP documented over 2,000 dead Mountain Whitefish on some affected stretches of the Yellowstone. With that, FWP estimates the total impact to Mountain Whitefish in the Yellowstone to be in the tens of thousands. In addition, FWP has received reports of rainbow and Yellowstone cutthroat trout mortality.
Test results from samples sent to the U.S. and Wildlife Service Fish Health Center in Bozeman show the catalyst for the fish kill to be Proliferative Kidney Disease, one of the most serious diseases to impact whitefish and trout. The disease, caused by a microscopic parasite, is known to occur in Canada, the U.S. and Europe.
It has been documented previously in only two isolated locations in Montana over the past 20 years. Recent outbreaks have occurred in Washington, Oregon, and Idaho. In trout, research has shown this disease to have the potential to cause 20 to 100 percent mortality. The parasite does not pose a risk to humans.
The effect of the disease on Yellowstone’s fish populations is exacerbated by other stressors like near record low flows, consistent high temperatures, and the disturbance caused by recreational activities.
In coming to the decision, the Department had to weigh the totality of the circumstances and risk to the fishery, according to FWP Director Jeff Hagener.
“We recognize that this decision will have a significant impact on many people. However, we must act to protect this public resource for present and future generations,” said Hagener.
“A threat to the health of Montana’s fish populations is a threat to Montana’s entire outdoor economy and the tens of thousands of jobs it sustains,” said Gov. Steve Bullock, noting that Montana’s outdoor recreation economy is responsible for more than 64,000 Montana jobs and nearly $6 billion in yearly economic activity.
In addition to the closure on the Yellowstone, FWP is asking for the public’s assistance in preventing the spread of this parasite by properly cleaning (CLEAN.DRAIN.DRY) all equipment prior to moving between waterbodies (i.e., boats, waders, trailers).
FWP has also set up two Aquatic Invasive Species decontamination stations set up along I-90 near the affected area in an effort to help reduce the chance of the parasite moving to other rivers.
source: Montana Fish, Wildlife and Parks