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Up to 10,000 Fish May be Dead in Yellowstone River Fish Die-Off

fish die-off
Bozeman Daily Chronicle

Montana officials are concerned as they estimate up to 10,000 dead whitefish in Yellowstone River.

File this under things that sound concerning: wildlife officials have confirmed a massive die-off of whitefish in the Yellowstone River.

While the number confirmed so far is around 1,000, the actual total could be much, much higher. "It would be fair to say we're over 10,000," Montana Fish, Wildlife and Parks spokeswoman Andrea Jones told the Bozeman Daily Chronicle.

The reason the confirmed number is lower is simply because many of the dead fish have likely already sunk to the bottom of the river. Others may have been eaten by scavengers.  "We're probably only seeing 10 percent of the impact," Jones told the paper.

Officials have only floated and surveyed a few stretches, but the dead fish have been found as far north as Springdale and as far south as Corwin Springs. It's a roughly 70-mile drive between the two towns along the banks of the river according to Google maps. The Corwin Springs area is about 11 miles north of the Wyoming border and Yellowstone National Park.

The die-off seems to only be affecting whitefish and suckers. The Bozeman Daily Chronicle reports FWP has unconfirmed reports of dead rainbow trout too.

FWP is now waiting for the results of tests at the U.S. Fish and Wildlife fish disease and health lab. Water samples are also being tested by quality specialists to determine if there's anything that could have caused the deaths in the water. They are also trying to see if there are human health concerns with the water.

The results of those tests won't be available for weeks however, so locals will have to wait to find out if the water is safe.

Associate conservation director for Montana Trout Unlimited, David Brooks, told the Bozeman Daily Chronicle whitefish are a sensitive species and a lower or hotter running river may make them more susceptible to diseases.

Meanwhile, FWP is planning to gather some live whitefish and trout for testing via electrofishing. The deaths of the fish were first reported last Thursday by local outfitters and river guides.

Unfortunately, the Yellowstone River incident isn't the first large-scale fish kill that's happened this year. Back in March, Florida's Indian River Lagoon had an unexpectedly large fish die-off. An equally mysterious die-off of sturgeon led to a fishing ban on them in Washington and Oregon last year.

For now, the Yellowstone River die-off remains a mystery. The first results of tests sent to the U.S. Fish and Wildlife service labs are due out later this week however.


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Up to 10,000 Fish May be Dead in Yellowstone River Fish Die-Off