The St. Lawrence Seaway reported a decline in overall cargo traffic through May 2026, with total cargo volumes down 3.3% compared with the same period in 2025.

According to monthly traffic data released by The St. Lawrence Seaway Management Corporation (SLSMC), total cargo reached 8.064 million metric tons through May, compared with 8.339 million metric tons during the same period last year.

Grain traffic posted one of the largest declines among major cargo categories. Grain shipments totaled 2.605 million metric tons, down 12.6% from 2.982 million metric tons in 2025.

General cargo also fell, declining 13.2% year over year to 485,000 metric tons from 558,000 metric tons. Liquid bulk cargo decreased 5.1% to 957,000 metric tons, while coal shipments declined 4.6% to 254,000 metric tons.

Several cargo sectors recorded gains during the period. Iron ore traffic increased 2.9% to 1.208 million metric tons, up from 1.174 million metric tons a year earlier. Dry bulk cargo rose 8.7% to 2.555 million metric tons, compared with 2.350 million metric tons in 2025.

Despite lower overall cargo volumes, vessel traffic remained steady. Total vessel transits reached 888 through May, up four transits, or 0.45%, from 884 during the same period in 2025.

Feature photo courtesy of Lower Lakes Towing/Mainstay Maritime