The Asian carp threatening the Great Lakes consists of three species: bighead, silver and black. The species were brought to the U.S. by catfish farmers because the carp ate algae and other organisms and keep the farmers’ ponds clean. A series of floods allowed the fish to find their way into local waterways. Eventually they migrated up the Mississippi River.
Labeled an invasive species by the Environmental Protection Agency, the Asian carp have voracious appetites, with an ability to consume up to 40 percent of their bodyweight each day. Mature carp can weigh 50 pounds — some reach 100 pounds — and can be more than four feet in length.
“The presence of Asian carp in the Great Lakes could cause declines in abundances of native fish species, and have been known to cause injuries to boaters,” said Ashley Spratt, who works for the U.S. Fish and Wildlife Service.
Phil Moy, a Sea Grant biologist at the University of Wisconsin-Madison, predicted that the Great Lakes are unlikely to see large hordes of Asian carp. He said it would take an abundance of carp to find rivers to spawn, but the current population in the Mississippi River system isn’t that large.