In the first 30 years of the St. Lawrence Seaway, the locks and channels opened for shipping 22 times in April, nine times in March.

Over the next 20 years, the Seaway opened in March all but twice.

Environmentalists say that means there's more days when freighters ply icy waters and more use of icebreakers.  Jennifer Caddick directs Save the River in Clayton.

And that icebreaking and ship passing in heavy ice can cause, has the potential to cause damage to some very sensitive near-shore habitat.  If there's a shipping accident or a spill, there is literally no way to clean up that spill in ice conditions until the ice melts.

The Department of Environmental Conservation says shipping can damage fish and wildlife habitat when there's as little as two inches of ice in the river's bays and shorelines.

The St. Lawrence Seaway says its U.S. and Canadian agencies decide when to open the shipping lanes using an elaborate process based on weather and ice forecasts.

Save the River has asked for that process to be made public for years.  It's filed freedom of information act requests.  But that didn't work.

So the group has filed a legal petition with the Seaway itself for the information to be released, says Caddick.

Specifically how they take into consideration environmental and safety concerns and balance those with the needs of the shipping industry.

A Seaway spokeswoman says the agency has received the petition and is giving it thorough consideration.  The agency announced on Tuesday that it plans to open for the Seaway's 51^st season on March 25^th.

For North Country Public Radio, I'm David Sommerstein.