Shipping on the Great Lakes and St. Lawrence Seaway: An Update

May 9, 2023 R47550

Shipping on the Great Lakes and St. Lawrence
Seaway: An Update
May 9, 2023
Congressional Research Service
https://crsreports.congress.gov
R47550

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Shipping on the Great Lakes and St. Lawrence Seaway: An Update

Introduction
For decades, the Great Lakes and St. Lawrence Seaway navigation system (Figure 1) has
provided efficient shipping for the raw materials that support the steel industry and other heavy
industries located in the region.1 However, shipping volumes have been in a long-term decline,
and many port wharfs remain vacant. Congress recently authorized substantial spending to
support the navigation system, including building a new lock at Sault Ste. Marie, constructing a
second U.S. Coast Guard heavy icebreaker, and rehabilitating several port facilities. In addition to
these capital improvements, the federal government operates and maintains the system by
keeping locks in good repair and dredging shipping channels and harbors. Given recent seaway
traffic trends and investments, this report provides an update and activity summary to CRS
Report R44664, The Great Lakes-St. Lawrence Seaway Navigation System: Options for Growth,
by John Frittelli (2016 CRS report).
Figure 1. Cross Section of Navigation System

Source: Figure created by CRS using St. Lawrence Seaway Management Corporation diagram.
Notes: The figures in meters are lake elevations above sea level. Lake Michigan is at the same elevation as Lake
Huron.
Traffic Trends
Steel plants located on the Great Lakes (the lakes) continue to be the prime movers for U.S.
shipping activity, with iron ore, the raw material for steelmaking, leading all other commodities in
shipping volume. In 2020, iron ore accounted for 42% of tonnage shipped on the lakes.2
However, as Figure 2 indicates, total U.S. shipping volumes have continued their downward
trend.

1 The Great Lakes consist of Lake Superior, Lake Michigan, Lake Huron, Lake Erie, and Lake Ontario. The St.
Lawrence Seaway connects these lakes to the Atlantic Ocean.
2 U.S. Army Corps of Engineers (USACE), Waterborne Commerce of the United States, Calendar Year 2020, at
https://www.iwr.usace.army.mil/About/Technical-Centers/WCSC-Waterborne-Commerce-Statistics-Center-2/WCSC-
Waterborne-Commerce/.
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Shipping on the Great Lakes and St. Lawrence Seaway: An Update

Figure 2. Annual U.S. Tonnage on the Great Lakes

Source: U.S. Army Corps of Engineers (USACE), Waterborne Commerce Statistics.
Note: Foreign is U.S. imports and exports to/from Canada and overseas countries.
Figure 3 shows the shipped tonnage over the last decade for the three leading commodities
shipped on the lakes: iron ore, limestone, and coal. A significant development since the 2016 CRS
report is the closure of the Escanaba, MI, iron ore dock. Because this dock was located on the
southern shore of Michigan’s Upper Peninsula, shipments did not need to pass through the Soo
Locks at Sault Ste. Marie, MI. The Escanaba docks remained open past the Soo Lock’s winter
closure (January 15 to March 25) and opened earlier than the locks in the spring. During its last
full year of operation in 2016, the Escanaba dock accounted for about 9% of iron ore shipped on
the Great Lakes. The dock closed after one of two iron ore mines to the north closed; the other
mine ships its iron ore from Marquette, MI, on the peninsula’s north shore.
Limestone, the second leading commodity shipped on the lakes in tons, is also a raw material of
steel manufacturing. It is used in blast furnaces to convert iron ore into pig iron. Limestone
shipping volumes are generally dependent on the steel market, although the construction industry
also uses limestone.
Coal shipping volumes are declining due to closures of coal-fired power plants or their
conversion to natural gas plants, a development not unique to the Great Lakes region. This
decline has affected the amount of thermal coal loaded at the Port of Duluth in Minnesota that
arrives by rail from Wyoming’s Powder River Basin.3 A lesser amount of metallurgical coal from
Appalachia is loaded at Sandusky, OH, and shipped to steel mills.4 According to the Lake
Carriers’ Association, which has compiled data for U.S.-flag carriers through 2022, coal shipping
volumes have rebounded somewhat from their low in 2020 but remain below their levels prior to
the Coronavirus Disease 2019 (COVID-19) pandemic.5
While foreign trade volumes have remained relatively stable compared with U.S. domestic cargo
(Figure 2), nearly all such foreign trade is with Canada. In 2020, only 17% of U.S. foreign trade

3 Pulitzer Center, “As Energy Use Changes in the Great Lakes, So Too Does the Port of Duluth-Superior,” April 28,
2020, at https://pulitzercenter.org/stories/energy-use-changes-great-lakes-so-too-does-port-duluth-superior.
4 Star Beacon, “Norfolk Southern Closing Ashtabula Docks,” December 24, 2015, at https://www.starbeacon.com/
news/local_news/norfolk-southern-closing-ashtabula-docks/article_37d4f173-bc9b-5caf-86bb-58b2d4143cc7.html.
5 Lake Carriers’ Association, “U.S.-Flag Great Lakes Shipping Down in 2022,” at https://lcaships.com/cargo-reports-
year-in-review-2022-u-s-flag-vessels/.
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Shipping on the Great Lakes and St. Lawrence Seaway: An Update

on the lakes was overseas trade, which necessarily would utilize the St. Lawrence Seaway. U.S.
exports of wheat and soybeans distinguish U.S. overseas trade using the seaway, but coal and
steel scrap exports, as well as steel product imports, also use this route. As measured by cargo
value, steel and aluminum products and machinery are the leading U.S. imports.6
Figure 3. Leading U.S. Commodities Shipped on the Great Lakes

Source: USACE, Waterborne Commerce Statistics.
Note: A short ton equals 2,000 lbs.
A second tier of commodities, identified in millions of tons rather than tens of millions,
encompasses several commodities shown in Figure 4. Sand/gravel shows an increasing trend
over the last decade. Salt is mostly rock salt shipped from Canada that is used for deicing roads in
the winter and for which volumes fluctuate from year to year. Asphalt is shipped primarily from
BP’s Whiting oil refinery in Gary, IN. BP states that this is the largest refinery in the Midwest,
producing 7% of U.S. asphalt.7 It appears most of the asphalt is shipped a relatively short distance
to Chicago. The Gary, IN, refinery appears to be the only U.S. refinery located on the lakes that
makes extensive use of waterborne shipping (there are six other refineries and several Canadian
refineries). Slag is the product left over after iron is extracted from ore. Some of it is used as
construction aggregate.8 Petroleum coke is a by-product of oil refining that steel mills can use for
fuel.9 Wheat is exported mostly to overseas markets from the Port of Duluth. Although gasoline
and diesel are shipped throughout the lakes, it does not appear that these products are shipped
directly from any refinery in significant quantity.10 No crude oil is shipped on the lakes.

6 U.S. Census Bureau, Economic Indicators Division USA Trade Online, U.S. Import and Export Merchandise trade
statistics.
7 BP, “Where We Operate,” at https://www.bp.com/en_us/united-states/home/where-we-operate.html. The refinery also
produces gasoline, diesel, and jet fuel.
8 U.S. Geological Survey, “Slag – What is it Good For?,” June 29, 2017, at https://www.usgs.gov/news/science-
snippet/slag-what-it-good.
9 CRS In Focus IF10507, Petroleum Coke: Industry, Health, and Environmental Issues, by Richard K. Lattanzio.
10 A federally funded research center on oil spill cleanup in freshwater bodies has been established at Lake Superior
State University in Michigan.
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Figure 4. “Second-tier” Commodities Shipped on the Great Lakes
U.S. volumes

Source: USACE, Waterborne Commerce Statistics.
Figure 5 shows the U.S. locations handling one million or more tons of the selected commodity
indicated in 2020. Most of the ports handling these commodities consist of a terminal or terminals
that are privately owned and/or completely utilized by a single shipper that is a vertically
integrated corporation. For example, Cleveland-Cliffs Inc. owns both iron ore and coal mines as
well as steel mills. Large agricultural trading firms or construction aggregate firms own other
ports or terminals. Ashtabula and Conneaut, OH, are transfer points for iron ore shipped by rail to
Pittsburgh area steel mills.
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Shipping on the Great Lakes and St. Lawrence Seaway: An Update

Figure 5. Selected U.S. Shipping Docks on the Great Lakes
Locations handling roughly one million tons or more of commodity indicated (2020)

Source: Figure created by CRS with commodity data from USACE, Waterborne Commerce Statistics.
Note: Marblehead, OH (near Sandusky), is the actual loading location for limestone.
Figure 6 shows snapshots of shipping volumes in 20-year intervals to illustrate long-term
shipping trends on the lakes and seaway. Because the COVID-19 pandemic distorted 2020
volumes, 2019 is used as the most recent year. The figure shows the mainstay commodities that
are shipped on the lakes. Iron ore volumes show a steady decline, as steel is increasingly
produced from scrap metal in mini mills that are plentiful and scattered throughout the country.
As explained in the 2016 CRS report, scrap metal can be readily transported by overland modes,
so location to a waterway and proximity to iron ore mines are not relevant to the mini mills. The
so-called integrated steel mills located on the lakes that make steel from iron ore cater to the auto
industry, which requires a higher grade of steel.11 Coal also exhibits substantial decline, although
the downward inflexion point is more recent (see discussion above). Grain crops show substantial
decline as the export destination market has shifted from Europe to Asia. Those commodities
associated with construction (asphalt, sand and gravel, cement, and slag) do not show a decline,
and some of them show an increase. Limestone is used in steel mills as well as in construction. In
sum, the deindustrialization of the Rust Belt is evident, but construction materials are making
ready use of lake shipping (as presented in Figure 6).

11 CRS Report R47107, Domestic Steel Manufacturing: Overview and Prospects, by Christopher D. Watson.
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Shipping on the Great Lakes and St. Lawrence Seaway: An Update

Figure 6. Mainstay Commodities Shipped on the Great Lakes
1979, 1999, 2019

Source: USACE, Waterborne Commerce Statistics.
Container Shipping Trying to Gain a Foothold Along the Lakes
As discussed in the 2016 CRS report, the Great Lakes are perceived as an unattractive waterway
for container shipping, which has kept the Great Lake ports from participating in a vibrant sector
of the shipping market. The unattractiveness of the seaway could be due to the transit time
required for passage through 15 locks each way, winter closure, and competition with railroads
from/to the ports of New York/New Jersey and Montreal. However, the Port of Cleveland has
partnered with a container carrier (Amsterdam-based Spliethoff) that provides service to northern
Europe. Import volumes have fluctuated between 13 and 75 TEUs per week on an annual basis
from 2014 to 2020,12 and the service has not been able to generate export volume.13 For the 2023
shipping season, the carrier has announced that in addition to calling at the Port of Cleveland
once per month, the carrier will add the Port of Duluth to its schedule.14 With the additional port
call, the carrier hopes to attract importers and exporters wishing to bypass Chicago rail
congestion. The Port of Duluth saw some new container business as a result of severe coastal port
congestion during the COVID-19 pandemic. The ships carrying containers on the lakes are often

12 TEU = 20-foot-equivalent unit, a measure of container shipping volume.
13 USACE, Waterborne Commerce Statistics, Waterborne Container Traffic, at https://usace.contentdm.oclc.org/digital/
collection/p16021coll2/id/1445.
14 Minnesota Public Radio, “Great Lakes Shipping Season Begins with Little Ice, New Cargo,” March 24, 2023, at
https://www.mprnews.org/story/2023/03/24/great-lakes-shipping-season-begins-with-little-ice-new-cargos.
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multipurpose vessels that are designed to also carry breakbulk (e.g., bags of flour on pallets) or
project cargo (large, oversized pieces like wind tower segments).15
A Nascent Cruise Business
In 2023, 170,000 passenger visits by cruise ships are forecasted on the Great Lakes, with 11
cruise ships operating in the region. This is an increase from 150,000 passengers and 9 ships in
2022. The ships on average each have accommodations for fewer than 200 passengers. U.S.
Customs and Border Protection has improved its services for processing passengers at certain
Great Lakes ports, which is expected to reduce inconveniences and delays at port calls.
Canada’s Traffic Remains Steady
Canada utilizes the St. Lawrence Seaway to a greater extent than does the United States and more
so for its domestic cargo than its overseas cargo.16 Canada’s commodity mix of products
resembles that of the United States, but volumes have remained steady over the last 20 years and
do not exhibit the United States’ long-term downward trend dating back to the 1960s. One
possible reason is that Canadian ships have experienced more balanced trade than U.S. ships
have, with outbound grain shipments from Thunder Bay, Ontario, and inbound iron ore from
Quebec. Canada exports several times more grain than does the United States out of the Great
Lakes, and the volume has been steadily increasing over the last 20 years.
Capital Investments
Great Lakes carriers, especially Canadian carriers, have invested in new ships, and a new U.S.
government icebreaker is on order.17 Shippers, along with federal and local governments, have
invested in new port facilities.
New Ships
The summer of 2022 marked the launch of the first large, self-propelled ship to have been built in
a U.S. shipyard for service on the Great Lakes in about 40 years. Fincantieri Shipyard in Sturgeon
Bay, WI, built the Mark W. Barker for the Interlake Steamship Company.18 It joins a fleet of about
30 vessels of similar size and design called “lakers.” The other lakers were all built before 1982,
with some dating to the 1950s. Like the rest of the laker fleet, the Mark W. Barker is designed to
carry dry bulk commodities (e.g., the iron ore, limestone, and coal discussed above). Lakers are
“self-unloaders” because they have conveyor belts along the bottom of the hull that extend out to
a boom on deck that can swing over a wharf to unload cargo. They require virtually no
dockworkers for offloading cargo. The ships are proportionally very long for their width because
the locks they pass through are relatively narrow.

15 BigLift Shipping, a sister company of Spliethoff, has shipped windmill parts into the Great Lakes.
16 St. Lawrence Seaway Management Corporation, “Traffic Reports,” at https://greatlakes-seaway.com/en/the-seaway/
facts-figures/traffic-reports/.
17 P.L. 117-263, §11104.
18 The Interlake Steamship Company, “M/V Mark W. Barker,” at http://www.interlake-steamship.com/our-fleet/mark-
w-barker/.
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Canada also has a fleet of self-unloaders on the lakes. Unlike in the United States, where the
Jones Act (§27 of the Merchant Marine Act of 1920, P.L. 66-261) requires all vessels engaging in
domestic commerce to be built in U.S. shipyards, Canada permits foreign-built ships and repealed
a 25% tariff on imported ships in 2010. Since then, the two Canadian carriers that own lakers
have replaced most of their fleet, purchasing 18 vessels, 16 of them from Chinese shipyards and
two from Croatian yards.19
Coast Guard Icebreaker on Order
The St. Lawrence Seaway closes from about the last week of December to about the end of the
third week in March, and the Soo Locks close from January 15 to March 25. Icebreakers are
needed to break ice in the days/weeks leading up to the closures (from about mid-December), to
aid in reopening the locks in March until about early April, and to extend the season for vessels
not using the locks. The U.S. Coast Guard has nine vessels in the Great Lakes capable of breaking
ice, and Canada has two.20 While Canada charges fees for its icebreaking services, the United
States does not. The Mackinaw is the largest Coast Guard icebreaker in the lakes. Congress
authorized $350 million for a second, similar-sized Great Lakes icebreaker in December 2022
(NDAA FY2023, P.L. 117-263, §11104), but it may take up to 10 years to design and build this
icebreaker in the United States.
A Parallel Soo Lock in the Works
At the Soo Locks site in Sault Ste. Marie, MI, the Poe Lock is the largest and the only lock that
can service the lakers transporting dry bulk commodities.21 The three other locks at the site are
smaller than the Poe Lock. Due to concern for the economic impact from having to close the Poe
Lock should a long-term repair be required,22 Congress has funded construction of a second Poe-
sized lock that would replace the two smallest locks. The most recent cost estimate of the project
is $3.2 billion, up from an earlier estimate of $922 million, with completion scheduled for 2030.
The U.S. Army Corps of Engineers (USACE) cites labor shortages, supply chain disruptions, and
increases in material costs as reasons for the project’s cost increase.23 Ships delivering cargo to
Canadian ports and U.S. ports do not pay tolls when transiting the locks.
Port Facility Improvements
The federal government has provided grants to Great Lakes ports to rehabilitate wharfs and
docks.24 In some cases, improvements were made with a specific shipper committed to using the

19 Algoma Central Corporation, “Domestic Dry-Bulk,” at https://www.algonet.com/business-units/domestic-dry-bulk/;
and CSL Group, “Fleet Renewal,” at https://www.cslships.com/en/our-operations/fleet-renewal.
20 CRS Report RL34391, Coast Guard Polar Security Cutter (Polar Icebreaker) Program: Background and Issues for
Congress, by Ronald O'Rourke.
21 The Poe Lock is about a third larger than the next largest lock, the MacArthur Lock.
22 U.S. Department of Homeland Security, National Protection and Programs Directorate, Office of Cyber and
Infrastructure Analysis, The Perils of Efficiency: An Analysis of an Unexpected Closure of the Poe Lock and Its Impact,
October 2015, at https://www.remi.com/wp-content/uploads/2021/08/DHS-OCIA-The-Perils-of-Efficiency-An-
Analysis-of-an-Unexpected-Closure-of-the-Poe-Lock-and-Its-Impact.pdf.
23 USACE, Detroit District, “New Lock at the Soo reauthorized in WRDA 2022 at $3.219 billion,” December 27, 2022,
at https://www.lre.usace.army.mil/DesktopModules/ArticleCS/Print.aspx?PortalId=69&ModuleId=29374&Article=
3254946.
24 These grants include two programs administered by the Maritime Administration within the Department of
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facilities; in other cases, facilities were rehabilitated in hopes of attracting new port tenants. For
example, at the Port of Milwaukee, a new grain elevator was constructed that will be used by
DeLong Company to export animal feed. Lafarge’s cement loading dock at Alpena, MI, was
upgraded as was a facility at Monroe, MI, for handling wind energy components. Other ports
have received grants to purchase or repair basic port infrastructure, such as wharfs and cranes, to
be more attractive in advertising for a tenant. Given the amount of dormant property zoned for
industrial use at many Great Lakes ports, some shippers are acquiring port land for commercial
purposes without an intention of using waterborne transport. Komatsu, an earth-moving
equipment manufacturer, purchased Milwaukee port property and built a factory and office
headquarters even though it appears that it is planning to use rail and trucks to move product in
and out of the factory.
Canada is rehabilitating vacant wharfs and land along the Welland Canal to increase room for
cruise ships and in hopes of attracting other waterway users.25
Seaway Maintenance
In addition to the Soo Locks, which USACE directly operates and maintains, the federal
government operates and maintains two locks on the St. Lawrence Seaway. (Canada is
responsible for 13 other locks on the seaway). The Great Lakes St. Lawrence Seaway
Development Corporation administers the U.S. portion of the seaway.26 USACE performs the
actual work of repairing the locks and dredging the channels in the seaway. The development
corporation’s expenses are funded out of the federal Harbor Maintenance Trust Fund, which is
supported by a tax on imported and domestic waterborne cargo at coastal and Great Lakes ports.
Lock repairs are scheduled habitually in the winter when the seaway is closed to navigation.

Transportation: the Port Infrastructure Development Program (https://www.maritime.dot.gov/PIDPgrants) and the
Marine Highway Program (https://www.maritime.dot.gov/grants-finances/marine-highways/grants). The BUILD grant
program (now RAISE grant program) also awarded a grant to Sault Ste. Marie for dock rehabilitation
(https://ops.fhwa.dot.gov/freight/infrastructure/tiger/).
25 Welland Tribune, “$45.3million (Can.) Invested into Welland Canal; Three Wharfs to be Reconstructed and Put
Back Into Use in Port Colborne with Federal Funding,” January 14, 2023.
26 Great Lakes St. Lawrence Seaway Development Corporation, at https://www.seaway.dot.gov/.
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Author Information

John Frittelli

Specialist in Transportation Policy

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