Shipments totaled 3,654,000 tonnes. Iron ore cargoes destined for steel manufacturers in the Great Lakes' region grew 127 per cent.

"These numbers reflect the integral role that the marine shipping industry plays in North America's emerging economic recovery — especially in the manufacturing sector," Richard Corfe, CEO of the St. Lawrence Seaway Management Corporation, said in a news release.

The corporation operates the Canadian portion of the seaway.

"It is apparent that the manufacturing industry is on the upswing and driving demand for commodities such as iron ore to make steel, which in turn becomes consumer goods such as automobiles," he said.

"With the economic rebound being experienced by the core industrial sectors we serve, especially the steel industry, we anticipate a higher level of fleet activity and crew employment levels this season," Allister Paterson, CEO of Seaway Marine Transport, said in a release.

Seaway Marine operates the largest bulk carrier fleet on the Great Lakes and St. Lawrence Waterway.