Iron ore shipments from Duluth-Superior are down 40% from 2025 and coal cargo has hit its lowest level since 1973, as US steel tariffs disrupt Great Lakes trade with Canada.
At a glance
- Iron ore shipments through Duluth-Superior, the Great Lakes' largest port by tonnage, are running 40% below their 2025 pace, with volumes down roughly 3 million tons year-over-year, mostly tied to weaker exports to Canada.
- Coal cargo at the same port is on pace for about 500,000 tons in 2026, down from 4.7 million tons in 2025 and the lowest level since 1973.
- Overall vessel traffic at Duluth-Superior is down 23% year-over-year through August; Canadian-flagged carriers have fallen further than US-flagged ones, down 37% versus 19%.
- The Great Lakes-St. Lawrence Seaway system normally carries about 200 million tons of bulk cargo a year between the US and Canada, a trade pattern built on a free-passage right dating to the 1871 Treaty of Washington.
What happened
Iron ore shipments moving through the Port of Duluth-Superior, the largest port on the Great Lakes by tonnage, are running 40% below their 2025 pace, with overall volumes down roughly 3 million tons year-over-year -- a decline driven mostly by weaker exports to Canada. Coal cargo through the same port has collapsed even further, on pace for about 500,000 tons in 2026 versus 4.7 million tons in 2025, which would be the port's lowest coal volume since 1973. Vessel traffic at Duluth-Superior is down 23% year-over-year through August, with US-flagged ships down 19% and Canadian-flagged carriers down 37%. The decline lands on a trade route built entirely around US-Canada integration: the Great Lakes-St. Lawrence Seaway system stretches 3,700 kilometers (2,300 miles) from Duluth-Superior to the Atlantic, moves roughly 200 million tons of bulk cargo a year -- including iron ore, coal, grain, limestone, salt, sand and stone -- and has operated under a right of free passage for US commerce dating to the Treaty of Washington in 1871. "Hope isn't a strategy, but we would expect that this trade war comes to an end," said Kevin Beardsley, executive director of the Duluth Seaway Port Authority. Ian Hamilton, president and CEO of Ontario's Hamilton-Oshawa Port Authority (HOPA), was more pointed: "Why are we disrupting this integrated market?"
The details
The Great Lakes-St. Lawrence Seaway system was built for one purpose: moving bulk commodities between the American Midwest and Canadian industry as if the border barely existed. Iron ore mined in Minnesota's Iron Range has flowed north to Canadian steel mills, and finished steel and other goods have flowed back south, for generations, carried by a specialized fleet of 1,000-foot lakers that cannot economically serve any other trade. That structure is exactly what makes a 40% drop in iron ore shipments and a collapse in coal tonnage to a 1973-era low so significant -- this isn't a market losing a marginal customer, it's a market losing the customer the entire route was designed around.
The mechanism connecting Trump-era steel tariffs to falling iron ore tonnage runs through Canadian steelmaking itself. Washington's Section 232 tariffs on steel, which doubled from 25% to 50% in mid-2025, made it more expensive for Canadian producers to sell finished steel into the US market that has long absorbed a large share of their output. Canada answered in kind, moving to impose its own tariffs of up to 50% on goods matching the US measures. When a Canadian steel mill sells less finished steel south, it also needs less iron ore shipped in to make it -- and iron ore is the single largest bulk commodity the Great Lakes fleet carries. The falling tonnage at Duluth-Superior is the physical, shippable evidence of that chain reaction, not merely the tariff dispute's headline number but its downstream shadow moving through hulls that once ran full.
The scale of what's exposed goes well beyond one port. Roughly 200 million tons of cargo move on the Great Lakes and St. Lawrence Seaway annually, underpinning a regional economy port authorities and shipping groups describe as one of the largest integrated industrial corridors in North America. Jason Card of Ottawa's Chamber of Marine Commerce pointed to a compounding structural problem: "It's difficult to find a shipyard willing to build a laker vessel," meaning the purpose-built fleet that serves this trade cannot easily be redirected or replaced if volumes keep falling, unlike more flexible ocean-going shipping. A route this specialized doesn't have an obvious substitute if the cargo it was built to carry keeps shrinking.
The Canadian-flagged fleet's steeper decline -- 37% versus 19% for US-flagged vessels -- also points to where the pain is concentrated. Canadian carriers depend more heavily on the cross-border iron ore and finished-goods trade that the tariff dispute has directly targeted, while US-flagged vessels retain more domestic-only routes as a partial buffer.
Why it matters
This story sits outside India's own metal-price charts, but it's a live example of the mechanism Indian buyers have been watching play out on copper and steel tariffs all year: a national-security tariff aimed at protecting one country's producers can end up cutting the raw-material demand that feeds the very mills it was meant to protect. For anyone tracking how Section 232-style tariffs ripple through global metal supply chains -- a framework already reshaping steel, aluminium and copper trade flows the world over -- Duluth-Superior's falling iron ore tonnage is a concrete, measurable data point showing that a tariff's second-order effects can hit a trade route with no direct stake in the original dispute.
Our read
Outlook: bearish. A 40% drop in iron ore shipments tied to weaker Canadian steel demand is a genuine loss of export volume for US Iron Range producers, which is a demand-side negative even though the story reports trade tonnage rather than a direct spot-price move. Confidence is moderate because the effect is inferred from volume data rather than a stated price reaction, and the underlying tariff dispute could still resolve and reverse the trend.
What to watch
- Monthly Duluth-Superior tonnage reports for iron ore and coal, as an early indicator of whether cross-border steel-sector demand is stabilizing or continuing to slide
- Any development in the US-Canada steel tariff dispute, since it is the direct driver of the Great Lakes cargo decline
- Canadian steel production and capacity-utilization figures, which feed directly into how much US iron ore Canadian mills need to import
For information only, not investment advice.
Iron price in India
metalscost.com India reference price as of 2026-10-03.
Detailed analysis
Timeline
- 1871-05-08: The Treaty of Washington established a right of free passage for US commerce on the St. Lawrence, the legal foundation for the modern Great Lakes-St. Lawrence Seaway trade route.
- 2025-06-01: US Section 232 tariffs on steel doubled from 25% to 50%, increasing costs for Canadian steel exporters.
- 2026-09-08: Canada's matching tariffs of up to 50% on goods corresponding to US Section 232 measures took effect.
- 2026-09-20: Reporting showed Duluth-Superior iron ore shipments running 40% below their 2025 pace and coal cargo on pace for its lowest level since 1973, with Great Lakes vessel traffic down 23% year-over-year through August.
Government Policies
US Section 232 tariffs on steel doubled from 25% to 50% in mid-2025, prompting Canada to impose matching tariffs of up to 50% on comparable US goods effective September 8, 2026 -- a tit-for-tat escalation that has reduced Canadian steelmakers' need for iron ore shipped through Great Lakes ports.
Trade Tariffs
Iron ore shipments through Duluth-Superior are running 40% below their 2025 pace, down roughly 3 million tons year-over-year, mostly attributed to weaker exports to Canada as US steel tariffs weigh on Canadian steel production and, by extension, Canadian demand for US-mined iron ore.
Geopolitical Risks
The Great Lakes-St. Lawrence Seaway trade route has operated on a right of free passage for US commerce since the 1871 Treaty of Washington; the current tariff dispute marks a rare disruption to a bilateral trade pattern that has otherwise held for over 150 years.
What could lift prices
- Port officials including Duluth Seaway Port Authority's Kevin Beardsley describe the disruption as tied to a trade dispute they expect eventually resolves, rather than a permanent shift in the underlying US-Canada industrial relationship.
What could weigh on prices
- Iron ore shipments through the Great Lakes' largest port are down 40% from 2025, with coal cargo on pace for its lowest level since 1973, showing broad-based cargo weakness rather than a single commodity's decline.
- The purpose-built laker fleet that serves this route has no easy alternative trade to shift into if volumes keep falling, and the Chamber of Marine Commerce says shipyards are already reluctant to build new lakers.
- Canadian-flagged vessel traffic has fallen more steeply (down 37%) than US-flagged traffic (down 19%), showing the tariff dispute's damage is concentrated rather than evenly spread, with no sign yet of a turnaround.
Country impact
| Country | Impact | Reason |
|---|---|---|
| United States | High | US iron ore mined in Minnesota's Iron Range and shipped through Duluth-Superior has lost a significant share of its traditional Canadian buyer base, with US-flagged Great Lakes vessel traffic down 19% year-over-year through August. |
| Canada | High | Canada's steel sector has absorbed direct damage from US steel tariffs, reducing its need for imported iron ore, while Canadian-flagged carriers on the Great Lakes have seen the steepest traffic decline of any group measured. |
Industry impact
| Industry | Effect | Reason |
|---|---|---|
| Maritime Shipping | Negative | Great Lakes bulk carriers, a purpose-built fleet with no easy alternative trade to shift into, have seen vessel traffic fall 23% year-over-year through August as the cargo the route was built to carry keeps shrinking. |
| Steel Manufacturing | Negative | Canadian steelmakers facing US tariffs on their finished steel are producing less and, in turn, importing less US iron ore -- the mechanism behind Duluth-Superior's falling ore tonnage. |
| Mining | Negative | US iron ore producers in Minnesota's Iron Range have lost a substantial share of their traditional Canadian export market as shipments through Duluth-Superior have fallen roughly 3 million tons year-over-year. |
Who gains, who loses
- Domestic steel producers shielded by Section 232 tariffs: US steel tariffs are designed to protect domestic steelmakers from import competition, even though the same policy has reduced Canadian demand for US-mined iron ore shipped through the Great Lakes.
- Great Lakes shipping companies and Iron Range ore producers: Falling cross-border iron ore and coal tonnage has cut vessel traffic sharply, with Canadian-flagged carriers hit hardest, while US iron ore producers lose a significant share of their traditional Canadian export market.
Other ways this could play out
- If the US and Canada resolve the steel tariff dispute, iron ore and coal volumes through Duluth-Superior could recover toward their 2025 levels as Canadian steel production and its associated ore imports normalize.
- If the tariff standoff persists, Great Lakes carriers and the ports that depend on them could face a more permanent restructuring, given how difficult industry figures say it already is to commission new purpose-built lakers even at current volumes.
Price risks
- Continued loss of Canadian export demand could pressure US iron ore producers to find alternative buyers or absorb lower shipment volumes, a headwind for Iron Range mining activity.
- A further escalation in US-Canada tariffs, rather than a resolution, could deepen the Great Lakes cargo decline beyond its current 40% shortfall.
Historical comparison
- Since 1973: Duluth-Superior's projected 2026 coal cargo of about 500,000 tons, down from 4.7 million tons in 2025, would be the port's lowest coal volume in over 50 years.
Technical view
Price is mixed relative to its 20-period and 50-period moving averages, showing no clear trend alignment.
Computed from metalscost.com's own stored price history.
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