Invasive African clawed frog population on the rise in Washington

The frogs are considered one of the worst invasive species on earth, according to the WDFW. They are ready on native insects and forage food eaten by native species.

ISSAQUAH, Wash. — An invasive species is consuming and competing with native species in western Washington, including salmon.

Scientists have spotted African clawed frogs in Issaquah, Lacey and Bothell, and the Washington Department of Fish and Wildlife (WDFW) is asking residents to be part of the solution.

The WDFW, nonprofit Trout Unlimited and other partners are all working together to combat the growth of the frog population.

The frogs were initially brought into the United States to be used in pregnancy tests, said Senior Research Scientist with WDFW Max Lambert. While the frogs are no longer used for that purpose, they became part of the pet trade. Although Washington made it illegal to own them, some still do. Some who have decided not to keep the frogs, and have instead released them into ponds and streams, have created a problem.

“It was a handful of years ago we first found them in Lacey and that’s really where we thought they were for a good chunk of time,” Lambert said. “We had some one-off instances of them in Bothell, first a single frog in Bothell and single frog in Issaquah.”

As WDFW began looking into the issue and working with landowners to set traps, the department discovered hundreds of frogs.

“These are considered one of the worst invasive species on earth,” Lambert said. “They’ve been introduced to Europe, Asia, sometimes in high numbers and they’re pretty darned good predators. They’ll eat a lot of native insects, which are good forage food for our fishes and our amphibians, they will eat tadpoles of our native salamanders, and they’ll eat fish. We looked at some of their stomach contents – and they’re full of baby fish.”

People working to restore salmon populations fear the frogs will infringe on that progress.

Since Trout Unlimited began trapping in January, the organization has caught about 300 frogs, Rebecca Lavier said. Around half of those have been found in the past few weeks. They believe this is just a fraction of the general population.

Lavier says she’s committed to the work because of the role it could play in supporting native species populations.

“Native species play a vital role in our ecosystem and we want to protect them,” Lavier said. “They make our region beautiful and it can be healthy- and it can be healthier- if we just take the time to observe and care for what we have.”

She, too, is asking illegal owners of the frogs to dispose of them properly or give them to someone else if they can no longer take care of them.

“You don’t just take a nonnative species and dump it into a pond,” Lavier said. “It’s not their habitat. They aren’t meant to be there and they can really wipe out the native species.”

WDFW wants to remind residents that it is not legal to have these frogs as pets. If someone does, they should keep it for its lifetime- or click here to learn more about alternate options. To get involved with volunteer projects through Trout Unlimited, click here.

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