The Great Lakes-St. Lawrence Seaway System officially closed for the 2025 navigation season on January 12. The system was supposed to close on January 5, but ice buildup created shipping delays, postponing the closure. It took several days for ships stuck in ice to make their way through the system. Several vessels were stuck between Cape Vincent and Massena, and near Montreal, Québec. Ice impacted traffic in Duluth, Minnesota, the St Marys River in Michigan, the Straits of Mackinac, Green Bay, Wisconsin, and the western basin of Lake Erie, including ports in Toledo and Sandusky, Ohio. 

In addition to the heavy ice developing early on the Great Lakes and St. Lawrence River, the Lake Carriers’ Association reported the U.S. Coast Guard’s (USCG) only heavy icebreaker, MACKINAW hasn’t been available, along with several smaller, 140-foot icebreaking tugs and an ice capable buoy tender.  The quick onset of winter caused problems for both the USCG and the Canadian Coast Guard (CCG) as they attempted to complete the annual removal of floating aids to navigation before ice damaged the buoys or moved them off station. That mission impacted icebreaking, delaying many federal icebreaking assets from assisting commercial traffic through ice that has formed across the Great Lakes.