In an unprecedented move, Montana Fish, Wildlife and Parks is closing 183 miles of the Yellowstone River from Gardiner to Laurel to all water-based recreation — fishing, wading, floating, tubing, boating.
No similar closure based on a disease outbreak has ever occurred in Montana, even when whirling disease was causing fish die-offs across the state in the 1990s.
"This significant action on the part of the department is in response to the ongoing and unprecedented fish kill on the Yellowstone," FWP said in an email. "This action is necessary to protect the fishery and the economy it sustains. The closure will also help limit the spread of the parasite to adjacent rivers through boats, tubes, waders and other human contact and minimize further mortality in all fish species." The parasite is not a threat to humans or animals that consume the dead fish.
The closure also affects all tributaries from Yellowstone National Park’s northern boundary at Gardiner to the Highway 212 bridge in Laurel.
Rafting and fly-fishing businesses were scrambling to respond to the closure. Angling trips start as early as 7 a.m., so boats were being pulled off the river.
"It's huge," said John Bailey of Dan Bailey Fly Shop in Livingston, noting that the closure isn't limited to the Yellowstone River. "The spring creeks and Boulder are closed. The Stillwater is closed. So you're talking about a major deal here. It affects a lot of people."
"The real question is when we will open," he added. "I don't think we'll open in September."
FWP information officer Andrea Jones said, "There is no timeline on something like this. We have to wait for the environmental conditions to improve and for the fish kills to stop."
Stillwater Anglers owner Chris Fleck, of Columbus, said he has conflicting feelings about the closure. On one hand it will hurt his business as he scrambles to find alternative options for clients, but he hopes in the long term it will be good for the fishery.
"I sure don't want to see a long-term problem," Fleck said. "I've got to believe they have the best science and advice."
News of the closure spread quickly across the nation. Pat Damico, a Pennsylvania dentist, has plans to fish Slough Creek in Yellowstone National Park with 14 other people next week and was worried that the closure might spread there. So far that hasn't happened.
"Crews are actively assessing the Yellowstone River and its tributaries inside the park’s northern boundary and have not discovered any dead fish," according to a park press release.
The park is asking anglers to disinfect their gear before traveling to the park and while within Yellowstone.
As Damico sought more information, though, he said he was getting conflicting reports from agency officials.
"We're sort of sitting on pins and needles because this is the big deal of the year," he said.
By Friday, roughly 4,000 dead fish had been counted, but the total number is estimated to be in the tens of thousands, including fish that sank to the bottom, officials said. Based on those figures, FWP estimates the total impact to mountain whitefish in the Yellowstone to be in the tens of thousands. FWP has also received reports of the kill beginning to affect some rainbow and Yellowstone cutthroat trout.
A survey of the river between Grey Owl and Loch Levin fishing access sites in the Paradise Valley on Friday turned up 1,895 dead whitefish, one rainbow trout and 13 dead longnose suckers.
Fishing guide Dan Gigone with the Sweetwater Fly Shop in Livingston said one of his guides reported seeing hundreds of dead trout Thursday. He called the closure catastrophic but said he would not fight the move.
"We have trips on the books through September," Gigone said. "It's definitely a big part of the Livingston and area economy. But we need to protect the resources as best we can for future years."
Test results from samples sent to the U.S. Fish 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 the disease to have the potential to cause 20 to 100 percent mortality. The parasite does not pose a risk to humans.
A similar outbreak of the parasite in Idaho in 2012 was mainly limited to whitefish.
"We did not institute any closures," said Dan Garren, Idaho Department of Fish and Game regional fisheries manager. "We never did document it in trout."
Every year since that first documented outbreak, Garren said dead whitefish have been found in the heat of the summer and the disease has been confirmed in the dead fish that were analyzed.
"So it's out there," he said. "It's one of those pathogens that are in the system, and it's probably not going anywhere.
"Frankly, we don't know if it's native or not."
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.
FWP Director Jeff Hagener said the decision to close the river was made by the Fish and Wildlife Commission in consultation with the director and governor after weighing "the totality of the circumstances and risk to the fishery.
“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,” Hagener said in a press release.
Fishing and floating outfitters have been supportive of the closure so far, Jones said. But how long that support would last in the face of a lengthy closure is still to be seen.
"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. "We must be guided by science. Our state cannot afford this infectious disease to spread to other streams and rivers, and it's my responsibility to do everything we can to stop this threat in its tracks and protect Montana jobs and livelihoods."
Bailey said there were few customers in his downtown Livingston store on Friday, and the upcoming Labor Day weekend is traditionally one of the busiest times of the year.
"It's very unprecedented," he said. "I'm not against this, but we don't know when it will end."
Bailey noted that stream flows won't increase until next spring.
In addition to the closure on the Yellowstone, FWP is asking for the public’s assistance in preventing the spread of the parasite by properly cleaning boats, waders and trailers before moving between bodies of water. FWP has set up two Aquatic Invasive Species decontamination stations along Interstate 90 near the affected area in an effort to help reduce the chance of this parasite moving to other rivers.
Those who violate the river closures will at first be educated. Persistent violations would lead to a citation being issued.
Associated Press reporter Matthew Brown contributed to this story.