On the morning after storms dumped nearly four and a half inches of rain on the city, Alody Flores woke up and discovered a plastic bucket in her garage half filled with little red “lobsters.” Thursday, August 22, got the most rain of any single day since 1987, and with it hundreds of strange red crustaceans came crawling up out of the murk in River Park, which spans the river between Argyle and Foster.
After Thursday’s storm, dozens of them were creeping through the grass on the east side of the river, where a small stream of storm water was running down the slope toward a chain-link fence and into the river beyond. They were red-and-black-colored crayfish, three to four inches long with freckly bumps on their pincers.
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During the storm, water treatment plants were deluged and the Metropolitan Water Reclamation District was forced to release some 1.7 billion gallons of untreated storm water and sewage overflow from the river into the lake. According to the MWRD, the water level on the stretch of the river in River Park–where the North Shore Channel cleaves from the North Branch–can rise and fall rapidly during such events, probably seven or eight feet at times. No one at the MWRD or the Chicago Park District had heard of any over-the-bank flooding on either side of the river there, though a manager at the CPD said he’d spotted landlubbing crayfish further south, in Horner Park.
Antonio figured that with the storms adding so much water to the river, the crayfish were trying to crawl ashore to avoid being washed away by the swifter current. He’d never eaten crayfish before but figured they were probably safe–the water wasn’t stagnant and people caught fish in that spot often enough.
“The red swamp crayfish was collected downstream of the treatment plant’s outfall canal,” wrote Thomas Simon in the spring issue of Lakeline. “The introduction may be the result of either well-intentioned aquarists releasing their pets into the ‘wild’ or the unwanted pets may have been discarded down the toilet and were able to survive the treatment filtration process.” Introduced species like the rusty and red swamp crayfish displace native crayfish and prey on fish and aquatic plants. “The Louisiana swamp crayfish could be the next big mess in the Great Lakes,” says Simon, who first discovered the creature at Zion’s Illinois Beach State Park two years ago. “They’re really tolerant of contaminated sediments. They’re obviously tough animals because there’s nothing else that lives on the bottom of the Grand Calumet.”
“I probably wouldn’t suck the heads,” says Huner, referring to the Cajun talent for extracting the “fat,” or yellow liver, located in the animal’s head. “That’s where you’d find concentrations of heavy metals and other pollutants. But the tail muscle is typically, in quotes, clean.”
