Binational Cooperation Key to Preventing an Asian Carp Invasion in the Great Lakes

Reaching lengths of a metre or more and weighing up to 50 kg, Asian carp consume about 40 percent of their body weight each day, reports www.megafishnet.com with reference to Fisheries and Oceans Canada.

Their voracious appetite and ability to frequently reproduce make these invasive species a potential threat to Great Lakes ecosystems and commercial and recreational fishers. While Asian carps are not yet established in the Great Lakes, their DNA has been detected in the Chicago Sanitary and Ship Canal, just a few miles upstream of Lake Michigan, and in the lake itself. Recently, Fisheries and Oceans Canada (DFO) provided assistance to a U.S. intervention effort aimed at eradicating Asian carps from the canal to prevent them from advancing into Lake Michigan and the other four Great Lakes.
The invasion front moves northward

In the United States, two species of Asian carps (Silver and the Bighead carps) escaped into the Mississippi River from southern aquaculture facilities in the early 1990s. Since then, they have been steadily moving northward, muscling out native fishes for food, space, and spawning habitat.

It is expected that these invasive species would cause similar problems here in Canada if they became established in the Great Lakes. "Nine out of 10 fishes pulled out of the Mississippi River basin are now Asian carps. This causes incredible problems and hardship for commercial fishers," says Becky Cudmore, Manager of the DFO Centre of Expertise for Aquatic Risk Assessment (CEARA) and Senior Advisor on aquatic invasive species. Silver carp - sometimes known as "flying carp" - are known to leap eight or more feet out of the water when startled, posing a hazard for fishers, recreational boaters and water skiers.
Highly suitable habitat in Canada for Asian carps

"Asian carps need to build up a large population to keep advancing so we still have a very good chance of keeping them out of Canada. Barring that, we have a very good chance of keeping the population numbers at the invasion front low and prolonging spread and impacts," says Cudmore.

While not all areas of the Great Lakes would provide suitable habitat for the carps, computer modelling carried out by CEARA indicates that Asian carps would have no problem surviving in Canada south of the 60th parallel. The modelling used temperature and other environmental characteristics in the Asian carps' native range and mapped those characteristics in Canada to find out where similar habitats exist. "Most of Canada lit up red, meaning it has highly suitable habitat for these species," says Cudmore.

Canada-U.S. collaboration in Illinois

For a week in December 2009, 18 Canadians - including 15 staff from DFO Central and Arctic Region, two from the Ontario Ministry of Natural Resources and one from the Ontario Federation of Anglers and Hunters - helped eradicate Asian carps from a six-mile stretch of the Chicago Sanitary and Ship Canal, a man-made waterway built in the 1920s to connect the Mississippi River to the Great Lakes.

"Most of the species in the canal system were invasive, and 90 percent of the biomass was common carp, so removal of those fishes was essential to prevent them from moving through the canal into Lake Michigan while the electric fish barrier was shut down for maintenance," says Cudmore. This massive effort involved 500 people from more than 20 agencies. DFO provided expertise on several components of the control and eradication program, including fish removal, as well as expertise and equipment from the DFO sea lamprey team to ensure that the chemicals used to remove the fish biomass from the canal didn't reach any natural waterways.

Bi-national cooperation is key

On October 5, 2010, the Minister of Fisheries and Oceans, the Honourable Gail Shea, announced a Government of Canada contribution of approximately $415,000 over the next 18 months to fund a new Action Plan to combat the threat posed by invasive Asian carps to the Great Lakes and their tributaries.

A comprehensive, basin-wide, bi-national Asian carp risk assessment will pinpoint key areas within the Great Lakes basin most vulnerable to invasion and identify likely routes through which they could enter the Canadian side of the lake system.

Results of the project will help to identify potential habitat and spawning locations for Asian carps, as well as transfer routes to help guide prevention, monitoring, rapid response, and control efforts by authorities on both sides of the border. By gaining a greater understanding of the potential spread, population numbers and specific impacts of Asian carps, we will be better prepared to take immediate, effective actions against any emerging threats to Canadian waters.

Ongoing cross-border collaboration will help protect shared freshwater ecosystems. Our efforts in Canada will supplement the work underway by the U.S. to implement their Asian Carp Control Strategy Framework and Action Plan.

Collaborative efforts between the U.S. and Canadian governments will further the aggressive response that is necessary to help prevent this invasive species from establishing itself in the Great Lakes.

"Since Canada and the U.S. share the Great Lakes, bi-national cooperation is essential to preventing an infiltration of Asian carps, because invasive species don't respect political borders. However, since there are no established Asian carp populations in Canada, the best thing we can do is help efforts underway in the United States to prevent them from moving northward," says Cudmore. "It's cheaper and more feasible to be proactive and deal with an invasive species when they're not even here. Canada spends $8 million a year dealing with sea lamprey in the Canadian Great Lakes, but we can't do that for all invasive species, so it's very important from both an economic and ecological point of view to prevent invasive species from getting here in the first place."