In its most recent performance report for November, the St Lawrence Seaway Management Corporation said total cargo on the Montreal to Lake Ontario section for the season through November was 27,799 metric tonnes, up 8.5% over 2011’s 25,585t.

At the same time, lock transits fell from 2706 through November of last year to 2664 through the end of last month.

Coal, which is leading the company’s commodity sectors in gains this year, spiked 83% year-on-year from 1.095Mt to 2.001Mt.

Iron ore also had a significant tonnage jump, growing 25%, from 7.506Mt last season to 9.357Mt this season.

Conversely, grain shipments were again a loser for St Lawrence, slipping from 7.317Mt in the 2011 season to 7.085Mt this season through November.

Dry bulk cargo, liquid bulk and general cargo shipments were also down.

Seaways officials noted total cargo across the seaway system was deflated. The most recent numbers show 3.804Mt last season but 3.629Mt this season.

The company has set a December 29 deadline for all vessels to exit the seaway’s most downstream lock, St. Lambert, or be suspended on the Great Lakes or St Lawrence River through the winter.

The Saint Lawrence Seaway Development Corporation, an agency of the US Department of Transportation, oversees the movement of marine traffic through US-owned and operated facilities of the Saint Lawrence Seaway.

It shares the system with Canadian counterpart Saint Lawrence Seaway Management Corporation.