What are invasive carp?

Fifty years ago, four species of carp from Asia were introduced to US waters. These carp escaped into the Mississippi River in Arkansas and have since invaded about one-third of the continent. The four species of invasive carp in the US are: silver, bighead, black, and grass. None are known to have effective predators in North America.
Carp are river-dwelling members of the minnow family. Silver carp (upper photo) typically weigh up to 25 pounds and bighead carp (top of page) weigh up to 80 pounds. Both eat large amounts of plankton, tiny organisms at the base of the food chain. Grass carp (middle photo) consume aquatic plants, and black carp eat mollusks. All four species compete with native fish for food. Silver carp are also dangerous because they jump.
Invasive carp have begun to enter MN and WI waters, including the Mississippi River. They dominate waters in many areas to the south, including Illinois, Missouri, and Kentucky. If we fail to stop them and they breed in our waters, our river ecosystems and fisheries will be radically changed for the foreseeable future.