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Yellowstone Revealed: Bullfrogs and tropical fish in the Tetons

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Posted at 3:41 AM, Dec 25, 2022

(Editor's Note: This year Yellowstone National Park celebrates its 150th Birthday. In honor of that historic milestone we're bringing you a new series called "Yellowstone Revealed." These reports offer a glimpse into the park's colorful history and stories that you've likely never heard before. This is the seventh installment - Bullfrogs and tropical fish in the Tetons.)

GRAND TETON, Wyo. - The coldest temperature ever recorded in Wyoming was in Grand Teton National Park, a whopping 63 degrees below zero. That was in 1933, but it is common for the temperature there to dip below 20 degrees below zero every winter.

But the park next to Yellowstone has been home to tropical fish from Asia and bullfrogs from the southern United States.

Buhhrup. Buhhrup. That is the call of a bullfrog that can be clearly heard at Kelly Warm Springs in Grand Teton National Park just south of Yellowstone.

Another bullfrog calls back. They are even visible in the middle of the day. And these may be tropical fish. That’s right: fish from the tropics. Bullfrogs and tropical fish live in Kelly Warm Spring, right in the middle of Grand Teton National Park.

When there’s snow on the Tetons, the temperature here can go 20 to 30 below zero. So it’s not a natural place for bullfrogs and tropical fish.

In 2016, Sue Consolo-Murphy was Grand Teton’s chief of science/resource management. She said: “We believe the source of non-native things here has been people who empty out their aquariums when they no longer wanted tropical fish in them.”

Consolo-Murphy is now retired. In 2016, she said there were goldfish in the spring and its streams, which flowed into the Snake River. She said the goldfish can get pretty big and compete with native cutthroat trout for food.

She says they will "directly eat the small frye of the native trout, which we’re trying to protect in the park.”

But where did the bullfrogs come from?

“Whether they used to farm them decades ago, or just had them as pets and decided to release them in the park… a well-meaning attempt, but it is illegal and inappropriate to introduce a non-native species into a national park," Consolo-Murphy said.

So what now? Consolo-Murphy said an ongoing study would discover where bullfrogs have spread, and what they eat.

“Some of them have gotten to be quite large, and their stomachs are filled with native species.”

Consolo-Murphy said a plan to remove the non natives was in process.

“We hope to address the management and potential restoration of this spring through an environmental assessment and management plan we’re preparing and hope to release for public comment this winter.”

And if the plan is implemented, it won’t be easy to get the intruders out of the Tetons.

“Elimination might be tough. There are thousands of them in here.”

Now, a park spokeswoman says: “The park has done some things to try to eradicate both bullfrogs and non-native fish in Kelly Warm Springs, but we have not been 100% successful to date. “

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