A New York state regulation intended to protect the St. Lawrence Seaway from invasive species may cripple shipping and hit Canada's economy hard, the shipping industry warns.

The new state regulation, which goes into effect in 2013, requires all ships entering New York waters to carry on-board water treatment systems and show they have extremely low levels of organisms in ballast water that may include invasive species.

"Close to a quarter of the gross national product … would be dramatically affected by that measure," said Jean Aubry-Morin, executive vice-president of corporate sustainability at the St. Lawrence Seaway Management Corporation, the Canadian non-profit group that co-manages the seaway with the U.S.-based Saint Lawrence Seaway Development Corp.

A 2008 study by scientists from the University of Notre Dame and the University of Wyoming found invasive species cost the eight U.S. states bordering the Great Lakes $200 million a year. For example, zebra mussels, which arrived in the 1980s, clog intake pipes, sink navigational buoys and compete with local species for food.

According to the Ontario Ministry of Natural Resources, about 60 new invasive species have arrived in the Great Lakes since the St. Lawrence Seaway opened in 1959. Many were carried from other parts of the world in ballast water, which fill tanks in the hulls of ships to keep them balanced.

Bruce Bowie, president of the Canadian Shipowners Association, said preventing invasive species from entering the seaway is important, but the problem with the New York standards is that they far exceed international and Canadian standards.

Technology doesn't exist: shipping industry

"There is no technology out there that can meet the New York standards," he told CBC's Quebec AM Tuesday. "What effectively New York is doing is stopping shipping into the Great Lakes."

Environmentalist Jennifer Caddick doesn't think the new rules will shut down shipping in the Great Lakes. 'I think that's a little alarmist,' she said. (CBC)

Bowie said ships carrying Canadian grain and ore to export markets must pass through New York waters, as two of the locks of the St. Lawrence Seaway are in New York.

He added that existing regulations targeted at invasive species have proven effective.

Anthony Ricciardi, a professor of biology at McGill University, acknowledged that no new invaders have been discovered since 2006, when Canadian regulations commonly known as "swish and spit" went into effect. Those rules have forced all ships to flush their ballast tanks in the open ocean, then refill them with salty seawater to kill any freshwater organisms before they enter the St. Lawrence Seaway.

However, Jennifer Caddick, executive director of the environmental group Save the Rivers in Clayton, N.Y., said she thinks New York's tougher new rules are a good idea.

"I'm just not willing to take the risk of damaging this freshwater resource for future generations," said Caddick, who has a family cottage on the seaway. "Who knows what the next invader would be that could come in and damage this water supply?"

She added that she doesn't think the new rules will shut down shipping in the Great Lakes.

"I think that's a little alarmist. It's time for the shipping industry to get these technologies on board their ships."

Bowie said he thinks it's unlikely, since companies that develop technologies for ships are interested in meeting international standards so they can sell their products around the world. He doubts they would take the trouble to develop technologies specifically for the small fraction of ships that pass through the St. Lawrence Seaway.