Meet The Lobster-Looking Menace Wreaking Havoc In Local Streams, Which Is Bad News For Everyone

The UCLA study is part of a long-term effort to understand the invasive crayfish and eliminate or reduce their numbers.

Tiny lobster-looking tyrants are taking over rivers and streams in the Santa Monica Mountains, and it's creating a huge health risk for Angelenos.

As a non-native species to the area, the red swamp crayfish might strike weekend hikers as out-of-the ordinary. That's because they are.

Research published this week from UCLA's La Kretz Center of California Conservation Science explains how this specific species has disrupted the food chain of the area, setting the stage for mosquito free-for-alls.

Basically, the crayfish eat everything in sight, including amphibians, plants and insects. Their presence has been hell on dragonfly nymphs, which feeds on mosquito larvae. Essentially, the crayfish are driving away the predators that were keeping the mosquito population in check.

That means more mosquitoes, which means a greater risk of diseases such as malaria, Zika and West Nile virus. And the problem goes far beyond Los Angeles and Southern California.

"They're everywhere," said biologist Gary Bucciarelli, who led the study. "They are excluded from Antarctica but I wouldn't be surprised if they somehow make it there someday. They are just that resilient."

Take Two listener and crayfish catching enthusiast Joel Goldes shared this photo of a recent catch with us. (Courtesy Joel Goldes)

Other invasive species like the bullfrog and the European garden snail were introduced to California for people to eat. But Bucciarelli says these crayfish are here because of misplaced crustacean empathy — they were used as fishing bait, but people started releasing them into the streams rather than let the leftover ones die. Now our ecosystem is paying the price.

The only solution, biologists say, is to catch and destroy them all. And the so-called "freshwater lobsters" are already on the menu in the U.S. as a staple in Southern cooking. But Bucciarelli warns that we shouldn't eat our way out of this crisis.

"They have the ability to uptake heavy metals that are in our waterways," he said. "It may not be a good idea to start eating them anytime soon."

Editor's note: A version of this story was also on the radio. Listen to it here on KPCC's Take Two.


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