After being introduced to control weeds and parasites in southeastern United States, Asian Carp species are quickly crowding out native fish species and are compromising water quality where they reside.

While there were initially seven species of carp native to Asia introduced into the United States, four species in particular that worry biologists and fishermen.  The bighead, black, silver and grass species of Asian carp have been deemed the most harmful species, laying hundreds of thousands of eggs at a time and quickly overrun new habitat.

Since their introduction, Asian carp have made their way as far north as the Great Lakes and last week a pair of commercial fishermen from Quebec confirmed the only known Asian carp in the St. Lawrence River.  The St. Lawrence River begins at the outflow of Lake Ontario, flowing back between Canada and the United States border before draining into the Gulf of Saint Lawrence, one of the largest estuaries in the world.

On May 27th, Pierre Thériault and Gerald Boucher hauled in a nearly 64lb. specimen that biologists estimate to be between 15 and 30 years of age.

“We really weren’t sure what it was. It looked like a carp… it had the same colour, but it was huge! We could see it was different from the others,” Thériault told CBC News.

As the fish was analyzed biologists found the fish’s belly was full of sterilized eggs, surprising researchers and biologists.

“We actually thought the Asian carp was confined,” biologist Michel Legault said. “But we know that in recent years the grass carp has been found in a small section of Lake Erie. And last summer, nine grass carp were caught in the Toronto area.”

The discovery of the species has kick-started Quebec’s Forests, Wildlife and Parks Ministry’s plans to fight the invasive species.  Making use of $1.7 million over a three year period, Legault’s team will attempt to detect Asian carp species in the river and educated commercial fishermen.

H/T: CBC News