MINNEAPOLIS — A strike has shut down all shipping on the St. Lawrence Seaway, interrupting exports of grain and other goods from Canada and the U.S. via the Great Lakes to the rest of the world.

Congress has authorized funding for a new icebreaker for the Great Lakes, a priority that the shipping industry and Sen. Gary Peters (D-Mich.) have sought for years to fight ice dams in the lakes and surrounding waterways.

Under an initiative announced at a United Nations climate gathering in November, preliminary plans are in the works for a “Great Lakes-St. Lawrence Seaway System Green Shipping Corridor Network.”

As the coronavirus pandemic locked down countries and disrupted global supply chains, the Great Lakes shipping season got underway last week, with extra precautions in tow.

The season’s first load of iron ore left the Duluth harbor before dawn March 22, carrying with it some extra cargo — caution over the spread of coronavirus.

As high water levels persist in the Great Lakes, some shoreline dwellers are putting pressure on officials to open up dams in the east to let out more water, but shipping industry officials in Duluth, Minn., and Superior, Wis., worry such a move thousands of miles away could have big consequences locally.

WASHINGTON — Members of Michigan’s congressional delegation raised concerns today that the Army Corps of Engineers may be considering an unorthodox alternative in a cost-benefit study that, if true, could potentially hurt the case being made for a new super-size navigational shipping lock at a key chokepoint on the Great Lakes.