• Two species of Asian carp — silver and bighead — were originally imported to
  control algae in southern catfish farms. Following flooding, they escaped
  into the Mississippi River in the early 1990s. They now inhabit the Illinois
  River, which connects to the Great Lakes via the Chicago Sanitary and Ship
  Canal.
• Silver and bighead carp consume vast amounts of food and are extremely
  prolific. They can weigh up to 100 pounds and grow more than four feet long.
  Silver carp can jump from the water when agitated and have been known to
  injure boaters.
• These species pose a significant threat to the Great Lakes ecosystem due to
  their large size, voracious eating habits, and rate of reproduction. Natural
  resource managers fear they would upset the food web, decimate native
  species, and damage the Great Lakes sport fishery.
  

Resources

• Asian Carp Management
• Great Lakes Commission