City Cast

Will Red Swamp Crayfish Hurt Chicago River?

Sidney Madden
Sidney Madden
Posted on August 17
Red swamp crayfish

Red swamp crayfish. (Carsten Koall / Getty)

What’s red, looks like a mini lobster, and has the potential to seriously affect local ecosystems? The red swamp crayfish, an invasive species that one ecologist is trying to remove from the Chicago River.

Where Did the Red Swamp Crayfish Come From?

Originally from the South, some theorize the five-inch crustaceans were used as bait or escaped from pet shops. Reuben Keller, a Loyola University freshwater ecologist, told WBEZ he suspects elementary schools probably released their class pets into the river at the end of the school year.

What Makes Red Swamp Crayfish So Dangerous?

As one of the most invasive species in the world, they compete with native species for food and habitat and can cause structural damage to property. That’s why they’re illegal in Illinois.

Red swamp crayfish served in Berlin

Red swamp crayfish served in Berlin. (Carsten Koall / Getty)

This Crayfish Isn’t for Eating … At Least in Chicago

Despite Louisiana fishers having long commercially harvested crayfish and Berlin chefs’ experimentation, Keller recommends not eating the ones found in the river because much of the population lives by a sewage plant. (That’s a different approach from when Asian carp got rebranded as copi.)

Who’s Getting Rid of the Crayfish?

Mostly Keller right now, whose lab has set up traps in the water that are emptied twice a week in the summer.

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