The Great Lakes shipping industry released a study Tuesday reporting that the industry supports 227,000 jobs in the U.S. and Canada, including about 2,500 direct jobs in Minnesota.
They include dockworkers, engineers, and also mining jobs on the Iron Range that depend on shipping.
"This report bears out what we've long known - that the Great Lakes-St. Lawrence Seaway is crucial to the U.S. economy," Transportation Secretary Ray LaHood said. He described water shipping as "the single most fuel-efficient and cost-effective way to haul goods from one place to another."
It says shipping over water saves about $3.6 billion a year in comparison to overland transport costs.
Steve Fisher, the executive director of the American Great Lakes Ports Association, said he hopes the data will help convince the federal government to do more dredging.
"It needs to be done to remove sand and silt that build up in the harbor naturally, to keep the shipping channels open so ships can access our ports," Fisher said.
Fisher, who's organization was one of the groups that commissioned the report, said the Army Corps of Engineers only partially dredges shipping channels. That means ships can't carry full loads of cargo.
"It's like flying half-full airplanes; it doesn't make sense," he said. "We don't want our cargo ships to have to operate half full either."
Fisher said the Coast Guard's ice breaking resources are also underfunded.
Some environmental groups have questioned the wisdom of allowing oceangoing vessels to enter the Great Lakes. The ballast water they discharge in port has introduced invasive species such as zebra and quagga mussels, which are believed to have caused billions in damages by clogging intake pipes, destabilizing the food web and promoting runaway algae growth.
The study by Martin Associates, an economic consulting firm in Lancaster, Pa., found that ocean ships - known as "salties" - contribute much less to the regional economy than the fleet of U.S. and Canadian ships that remain in the area. Even so, transoceanic vessels are crucial because they provide a direct link between the Great Lakes region and overseas ports, Fisher said.
"They enable our farmers to export grain and sell their products overseas," Fisher said. "They're essential to helping our manufacturers compete overseas."
Thom Cmar, an attorney for the Natural Resources Defense Council, said the report was "extraordinarily one-sided."
"It's undeniable that shipping has a big economic footprint, but the better question is what are the alternatives and what are the investments that need to be made going forward to deal with the downsides of shipping," Cmar said.