"They would be quite abundant," said Ed Rutherford, a fisheries biologist with the federal Great Lakes Environmental Research Laboratory in Ann Arbor and a member of the study team, which included scientists from several U.S. and Canadian universities and government offices.
The carp, which have overrun the Mississippi River and many of its tributaries since being imported to the southern U.S. from Asia in the 1970s to cleanse sewage treatment ponds, gorge on tiny plants and animals known as plankton that all fish eat at some point in life. They are migrating northward toward the Great Lakes, where agencies have spent more than $300 million to keep them out.