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The Bullfrog and Thistle: Can the Northwest Eat a Way Out of Ecological Threats?

November 25, 2015

Armed with a flashlight and a spear under the cover of night, Tom Kaye creeps toward his targets on the edge of a pond near Corvallis.

"There's the one we're going to go after first," he says. "I can see some twinkling eyes and then there's several all the way up the shore."

Invasive American bullfrogs have taken over the pond, and that's bad news for native species.

"Bullfrogs are a major predator in aquatic systems," Kaye says. "They eat basically everything they can stuff into their mouths: Fish, other frogs, small birds, ducklings, goslings. They'll eat rodents."

Kaye wants to turn the tables on these hungry predators – by putting them on the dinner table. But he has to catch them first. His plan is to fry up a big batch of frog legs.

"The way I prepare them is: you take the frog leg and you coat it in egg yolk and dip it in cornmeal, and fry it in cornmeal and then lightly fry it in peanut oil, and it makes a really nice, easy-to-eat and delicious meal," he says.

'Eradication by Mastication'

Kaye directs the Institute for Applied Ecology in Corvallis. The group restores native habitats, and that means facing the daunting task of controlling invasive species. They draw people to their cause by showcasing invasives you can eat in an annual feast and cooking competition called "Eradication by Mastication." They even put out a cookbook of invasive species recipes called They're Cooked.

Instead of pulled pork, Kaye says, you can have pulled nutria – using the meat from an invasive rodent. Rather than popcorn shrimp, their cookbook has a recipe for popcorn starling – an invasive bird.

"Many invasive species are quite edible – and delicious, even," Kaye says. "There's an interesting 'ew' factor around eating invasive species like nutria or frog legs. It really seems odd to a lot of people, so they're at the same time repulsed and fascinated."

Invasive crayfish dip

The institute's ecologist, Ben Axt, has a great recipe for invasive crayfish dip.

Step one: head to the nearest river or lake. He traps red swamp crayfish in local ponds near his office.

"They're in most of our major waterways and they're pushing further and further out all the time," Axt says. "You can tell it's red swamp crayfish from the native one because it has these bumps on the claws."

Invasive crayfish eat fish eggs and edge out native crayfish, Axt says. They also burrow into the mud and stir up sediment that makes it harder for other species to survive. The good news is they taste like little lobsters.

"These are tasty," he says, holding up one of the crayfish he trapped. "I'm going to steam them up and make them into a kind of a crab dip. Should be pretty good."

Thistle dandelion quiche

If you're a vegetarian, there are plenty of problem plants you can eat. Jennie Cramer is a botanist with the institute. She has a way of cooking invasive Canada thistle – a hostile-looking plant with thorny leaves – into a quiche that won't puncture people's mouths. It's easy to find, she says, because it's such a ubiquitous invader.

"It's all over the state. It's all over the country. It's pretty much all over the Northern hemisphere," Cramer says. "You'll find it in places that have been disturbed. Usually there's been either some development or logging of some kind, maybe a landslide or erosion or grazing."

Believe it or not, she says thistle can actually be tasty – with the proper cooking method.

"It does have thorns, but when you boil the leaves the thorns will kind of fade away and then you can cook it in butter and it will taste really good," she says. "If you take the stems and peel back the outer layer, the inside is actually pretty tender on the younger parts of the plants. You can eat it like asparagus – raw or cooked."

At home, she mixes the thistles with dandelion greens, herbs and veggies from her garden to make a quiche.

"I'm masking the wild flavors a little bit on purpose because they are pretty potent and we want it to taste good as well as be eradicating our invasive species," she says.

Not really the solution

Even with lots of fun and tasty options, Kaye says eating invasive species isn't really the solution – but it does get people's attention.

"We don't really think we're going to eat our way out of this problem," he said. "It's really an awareness method to bring to to the fore the fact that we have these invasive species and bring people to the table – literally – to eat them and talk about them and the damage they're doing in a more lighthearted environment. Because let's face it: some of the impacts they're having are pretty devastating and depressing."

He's found sharing a recipe or a meal can make facing the challenge of invasive species a bit more palatable.

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Ben Axt, an ecologist with the Institute for Applied Ecology, traps invasive crayfish in a pond near Corvallis. He steams them and adds the tail meat to a cream cheese dip.

Nick Fisher/OPB