In 2009, Illinois treated a six-mile canal with more than 1,800 gallons of fish-killing poison — and found just one invasive carp

To address the menace of invasive Asian carp, Illinois officials deployed rotenone in a canal, leading to the recovery of numerous fish; however, they could only pinpoint a single bighead carp. The undertaking took place during routine maintenance of an electric barrier, highlighting the complexities of managing these invaders and reinforcing the importance of a multifaceted defense strategy to safeguard the Great Lakes.