In 2017, an estimated 194 million metric tonnes worth about $73 billion USD ($95 billion CAD) were carried on the Maritime Transportation System. This includes the Great Lakes, St. Lawrence Seaway, and St. Lawrence River downstream to Les Escoumins, QC. The figures below illustrate how this cargo tonnage and value was broken down by different commodities.
Bulk cargoes such as iron ore, stone, grain, and coal make up the majority of the tonnage of goods moving on the MTS. However, containers carried on the MTS make up the largest share of value. This difference in the shares of value and tonnage reflect the fact that bulk cargoes have a relatively low-value per ton, while containerized cargos are usually manufactured products that have a greater value per ton. A further discussion of MTS container traffic and trends is here.
While the value metric above presents the market value of cargo moving on the MTS, it is important to remember that the true value of this cargo is greater than its market value. This “hidden” value is due to the fact that many of the commodities moving on the MTS are crucial inputs to manufacturers producing higher-value goods. For example, the iron ore moved on the MTS has a relatively low value based on market price, but this iron ore is the critical component to higher-value US and Canadian steelmaking, and thus secondary manufacturing industries such as automotive, machinery, and appliance producers. Without access to the materials, many of the region’s manufacturers would not be able to operate.
It is also important to note that the tonnage and value estimates presented here are estimates, and their full accuracy is not guaranteed. There are no publicly-available, comprehensive sources of data on the tonnage or value of cargo carried on the MTS. This lack of binational, comprehensive data means that estimates of tonnage and value must be created using multiple data sources, which often have differing reporting or collection methodologies, or restrictions on how data may be disclosed. This estimate of tonnage and value was created using three main sources:
- Estimates of cargo tonnage and value for the Great Lakes and St. Lawrence Seaway from the Martin Associates 2018 study: Economic Impacts of Maritime Shipping in the Great Lakes – St. Lawrence Region.
- Data on cargo tonnage loaded and unloaded at the ports of Montreal, Quebec City, Saguenay, and Trois-Rivieres from the Maritime Information System.
- Lake Carriers’ Association data on iron ore shipments carried by US-flag vessels for transshipment to ocean vessels in Quebec City.
This use of multiple data sources and confidentiality restrictions with some sources means that some shipments (particularly for Canadian-flag vessels) may be over-counted, some cargos are classified differently between datasets, and not all ports in Quebec are counted. The Great Lakes Commission and the Blue Accounting Maritime Work Group are continuing to work on improving the accuracy of metrics for tonnage and value.