MILWAUKEE (AP) — A conservation group has proposed banning ocean freighters from the Great Lakes in an effort to halt the onslaught of invasive species.

Great Lakes United says shutting the St. Lawrence Seaway to seafaring ships is akin to closing a small factory that pollutes a town with its oversized smokestack. The freighters, it says, are bringing in invasive species that ravage native fisheries, ruin beaches and cost water-dependent industries billions of dollars.

At least 183 foreign organisms now thrive in the Great Lakes, and a new one is discovered about every six months. Research has shown that most arrive on overseas vessels that take in water in foreign ports.

The U.S. shares ownership of the St. Lawrence with Canada, and both countries would have to agree to a ban. But lawmakers say support for the idea is growing.

“Three years ago, I’d have said, ’That’s a little radical,”’ said Patty Birkholz, a Michigan state senator and Republican who has pushed for greater ballast regulation. “Now, it’s probably more realistic.”

Invasive species often are carried into the Great Lakes in ships’ ballast water. Some evidence indicate the costs of this pollution may outweigh the economic benefit of shipping.

A draft study from the U.S. Army Corps of Engineers indicates recreational boating contributes more to the region’s economy than shipping, and it is dependent on the health of the Great Lakes.

“I’d personally be very much for outlawing the salties,” said Racine Mayor Gary Becker, vice chairman of the Great Lakes and St. Lawrence Cities Initiative.

He said he would welcome the ships back once they have figured out how to stop polluting the lakes.

Great Lakes United has taken a similar position. Rather than proposing a permanent ban on oceangoing freighters, it has said ships should be blocked from the Great Lakes until they are equipped with sterilization systems for their ballast tanks.

The overseas shipping industry says that will take time. It advocates federal legislation phasing in ballast treatment systems.

At the same time, the industry has burned much of its goodwill by suing the state of Michigan over a new law restricting contaminated discharges — particularly since other states, including Wisconsin, are looking at similar legislation.

U.S. Rep. Vernon Ehlers, R-Mich., called the proposed ban on oceangoing ships “a serious proposal.”

Posted 4/23/2007