Ontario Federation of Anglers and Hunters ID dangers of Asian carp invasion at Toronto information session

File photo

by Jan McQuay

TORONTO—They’re prolific, they grow quickly, they have few predators, and they’re hardy, able to adapt and thrive in a variety of conditions. There’s not much to hold the Asian carp back once they get into a watershed.

The danger of an Asian carp invasion in Canada is real. At an information session held by the Ontario Federation of Anglers and Hunters (OFAH) in Toronto on February 3, several speakers explained different aspects of the problem.

Becky Cudmore of the federal Department of Fisheries and Oceans presented a map showing in red the regions where environmental conditions could favour the survival of these fish. Most of Ontario was red. The invaders are now just 37 miles from Lake Michigan, having infested the Mississippi River and up the Illinois River. The Chicago Sanitary and Ship Canal, which connects the Illinois River to Lake Michigan, is a potential pathway for them to migrate into the Great Lakes.

Filmmaker Scott Dobson gave the audience a sense of the infestation in Illinois using photos from his film ‘Carpe Diem: A Fishy Tale.’ The images of dozens of silver carp jumping out of the water in Lake Peoria and the Illinois River are surreal. They out-compete native fish, growing to 30 centimeters in the first year, quickly becoming too large for predator fish to attack. In some places they account for 90 percent of the fish biomass. Biodiversity is lost, few other species remain. The invaders have destroyed the fishery, and people have stopped using Lake Peoria for swimming, boating and recreation. If you’re in an open boat you’ll need strong netting for protection. These are big fish, averaging more than 30 lbs.

There is a ban on the possession, transportation or sale of live Asian carp in Ontario. Still, people have tried to flout the law, putting the entire Great Lakes at risk. Between 2005 and 2013, there were 20 convictions for violations, and over 40,000 lbs of live Asian carp were seized, according to speaker David Copplestone of the Ontario Ministry of Natural Resources and Forestry (MNRF).

There are four species of Asian carp: sliver, bighead, grass and black. Grass and silver carp are primarily plankton eaters, and in the 1970s they were deliberately and legally stocked in fish farms and municipal sewage lagoons in the US to control algae. The first were introduced at a fish farm in Arkansas. In flood conditions, they escaped the fish farms and lagoons into the river systems.

An Asian carp invasion into the Great Lakes would devastate the native fish and upset the ecology, as well as fisheries and recreation. Early detection is essential, the group learned. Governments are asking the public to help by learning to identify and reporting any sightings. Asian carp are sometimes confused with the common carp, but Asian carp have a dorsal fin attached to a small area on their backs, while common carp have a dorsal fin that runs down much of the length of their back.

The MNRF is monitoring the Great Lakes closely, taking samples of water and testing them for traces of DNA. As Mr. Copplestone explained, fish leave bits of their DNA in their wake as they swim around, like a truck on a dirt road leaves a cloud of dust behind it. With water samples, MNRF can do e-DNA tests to discover if certain species are in the water, without having to find an individual. The good news is that tests completed in the Great Lakes so far have ruled out the presence of live Asian carps able to reproduce.

Researchers on both sides of the border are conducting studies. Professor Nicholas Mandrake of the University of Toronto described his research into how Asian carp could migrate. If they got into Lake Ontario, could they migrate up the Welland Canal into Lake Erie and from there into the Upper Great Lakes. His research on common carp tagged at the Welland Canal shows they can indeed move through the locks. For thousands of years, Niagara Falls provided a natural barrier preventing fish from migrating from Lake Ontario to Lake Erie, but the Welland Canal has provided an alternative route. New effective barriers need to be found.

OFAH’s Invading Species Awareness Program is raising awareness and encouraging people to help. More info is available at www.invadingspecies.com. Anyone with information about the unlawful importation or distribution of live Asian carp should call the MNRF at 1-877-847-7667.