Sea Lamprey Control Sea lampreys are aquatic vertebrates native to the Atlantic Ocean. Sea lampreys resemble eels, but unlike eels, they feed on large fish. They can live in both salt and fresh water. Sea lampreys, now found in all the Great Lakes, attach to fish with a sucking disk and sharp teeth.
Sea lampreys feed on body fluids, often scarring and killing host fish.
During its life as a parasite, each sea lamprey can kill 40 or more pounds of fish. Sea lampreys are so destructive that under some conditions, only one of seven fish attacked by a sea lamprey will survive. Sea lampreys have had an enormous negative impact on the Great Lakes fishery. Because sea lampreys did not evolve with naturally occurring Great Lakes fish species, their aggressive, predaceous behavior gave them a strong advantage over their native fish prey.