The St. Lawrence Seaway experienced a rebound in activity over the course of the 2010 navigation season, with a 15% increase in cargo volume yielding an estimated total of 35.5 million tonnes. Shipments of iron ore posted a strong 35% gain over the level witnessed in 2009. Grain likewise showed improvement, posting a 10% increase year over year. Coupled with a 63% surge in general cargo, which consists principally of iron and steel break-bulk shipments and project cargo such as wind turbine components, the Seaway finished the year on a positive note. “With a recovery in the manufacturing sector, characterized by a resurgent domestic auto assembly business…