Continued demand for iron ore, coal, and general cargo for the industrial and manufacturing sectors lifted the tonnage numbers along the Great Lakes-Seaway System to the positive column. For the period March 22 to November 30, year-to-date total cargo shipments were 34.6 million metric tons, a rise of 2.67 percent over the same period in 2011. The St. Lawrence Seaway reported an 11 percent increase for total cargo shipments during the month of November – 5.1 million metric tons – compared to November 2011. “The nearly 3 percent rise in overall tonnage handled through the Seaway in 2012 is due in part to the proven formula of ‘steel in, grain out’ as steel imports rose 12 percent in November as compared to the same month last year, and combined Canadian-U.S.