Another exotic species of fish is threatening to wreak havoc on the lucrative Great Lakes fishing industry. But, even though the threat is real, experts aren't sure exactly how to stop it.

Sometimes growing to more than 120 pounds, the Asian Carp are considered a bold, destructive invader species, capable of devouring all the food needed by native species.

Described as fish-farm escapees from the Mississippi Delta, the rapidly-multiplying Asian carp have been making their way north for more than a decade.

And that has those with a special interest in the Great Lakes worried.

"It would be very devastating," Herb Gray told CTV News, speculating on their arrival in the massive freshwater system.

As Canadian Chair of the International Joint Commission on Canada-U.S. transboundary issues such as air and water, Gray has had time to contemplate the consequences.

"In fact, if Asian carp got into the Great Lakes and began breeding ... it would mean the end of the domestic species," he said.

And he's clearly not alone in his concern. As U.S. federal fisheries expert Jerry Rasmussen told CTV, the carp are demanding of their environment.

"A large critter like that consumes a lot of food," Rasmussen explained, noting their "tremendous biomass."

"That takes a tremendous amount of food out of the water, and it has to come from somewhere."

If they find their way into the Great Lakes, it is feared they could cripple the multibillion-dollar sport and commercial fishing industry there.

Wary of their advance up the Illinois River toward Lake Michigan, the U.S. Army Corps of Engineers have built an electrified barrier near Chicago.

The $9.1 million US barrier has been designed to contain the spread of the exotic aquatic life, but unfortunately there's no easy way to test its effectiveness.

Critics have already said the barrier will do little to stop transport ships from ferrying the Asian Carp's eggs in the ballast tanks they frequently fill and empty to level their loads.

The Asian Carp is not the only foreign species to threaten the Great Lakes ecosystem. In fact, it is just one of close to 200 species introduced by foreign ships since the St. Lawrence Seaway opened the Great Lakes to seagoing traffic less than 50 years ago.

With that in mind as the 2005 shipping season returned to business last week, the environmental coalition Great Lakes United called on the Canadian and American governments to adhere to a strict new international convention on ballast water recently adopted by the International Maritime Organization.

With files from CTV News