The Great Lakes Fishery Commission in Ann Arbor, Michigan says that the sea lamprey population is increasing in the St. Clair River and Lake Erie.
However, Communications Director Dr. Marc Gaden says more aggressive preventative measures and controls are being introduced to prevent significant damage to fish stocks by the destructive predator.
The commission believes that sea lamprey populations are rebounding from the harsh winters of 2013-2014.
Gaden says sea lampreys prefer trout, salmon, whitefish, and sturgeon, but they also attack smaller fish like walleye and perch.
"Had a profound negative effect on fish in the Great Lakes. They attach to the fish with their suction cup mouth and bore a hole through the fish, feeding on their blood and body fluids and we would lose hundreds of millions of pounds of fish every year to lamprey before we brought them under control," says Gaden.
The commission says the Great Lakes fishery in Canada and the U.S. is worth $7-billion annually.
Gaden says sea lampreys were killing about 103-million lbs of fish per year before the controls but now that number is down to less than 10-million lbs.
Gaden says the sea lamprey is one of the worst human-caused ecological disasters ever inflicted upon the Great Lakes but it's not as bad as the Asian Carp.
"On Lake Erie right now we estimate there are about 13,000 lampreys in the lake. The target is about 4,000. So, we're quite a bit above target in Lake Erie," Gaden says.
Gaden says sea lamprey control includes lampricides, barriers, traps and chemosensory cues to disrupt spawning behavior.
"Lake trout are not living long enough to reach a reproducible age, which makes it hard to sustain the fishery. That's the kind of long term thinking that we face with something like a lamprey control program," says Gaden.