Last week, tens of thousands of fish were poisoned when officials poured more than 8,000 liters of fish poison into a stretch of water that connects the Mississippi River and Lake Michigan, reports . The poison, rotenone, was used as a drastic attempt to try to keep invasive Asian carp out of the Great Lakes (the electric shock barrier that usually keeps them out was having maintenance work done). Officials fear that if the carp are not stopped, they will overpower native fish species that are crucial to the lakes' sport and commerical fish industry, which brings in $7 billion per year. Apparently, only one bighead carp was found among the thousands of dead fish, but it is thought that the rest of the dead carp may have simply sunk to the bottom of the canal.
“We can't afford not to do everything possible to keep the Asian carp out of the Great Lakes,” said an Illinois Department of Natural Resources representative in the article.
— Lisa Lombardi