The Canadian government has commissioned a study in the fight against the Asian carp, fish that have been called the Great Lakes' greatest threat.

Fisheries Minister Gail Shea says a joint Canadian-American risk assessment will examine the ways the fish could make their way into the Great Lakes.

"The action we are announcing today will result in a better understanding of potential entry, the establishment, the spread and the impact of Asian carp," Shea said in Toronto.

The $415,000 study will examine the carp's food supply, and the biological impact the fish could have on the region.

Scientists worry that if the carp make it to Lake Michigan, they could spread to most of the Great Lakes and eat up enough plankton to collapse the entire US$7-billion fishery.

"We've seen what they've done to the Mississippi basin. They're ferocious feeders -- wipe out lower food chain so other fish can't survive," Robert Lambe of the Department of Fisheries and Oceans said Tuesday.

Shea said she wants to prevent the carp from gaining a foothold in Canada, like they have in the southern U.S. The fish were first imported from China in the 1970s to control algae at fish farms. But they escaped into the Mississippi River and have been making their way north ever since.

The U.S. government has poured US$30 million into preventing the carp's spread this year alone and has identified 30 waterways through which they could potentially reach the Great Lakes.

U.S. officials have gone so far as to attempt to poison the fish, and build electric barriers near Chicago to keep them out of Lake Michigan.

The carp's size is also of concern. Carp can consume up to 40 per cent of their body weight daily. When fully grown they can be 1.2 metres long and up to 45 kilograms.

They are known to jump a metre high out of the water and have caused concussions and broken bones to unsuspecting boaters.

Department of Fisheries and Oceans scientist Nick Mandrak said he was struck in the kidney by a flying carp during a trip to Illinois. A colleague was hit in the face.

"There have been reports of people getting broken noses or broken jaws from getting hit in the face by these fish," Mandrak said.

With a report from CTV's John Vennavally-Rao