Oil Tankers In
Canadian Waters #clearfacts #tankers101

The recent approval of pipeline projects in Canada is expected to increase the amount of oil tankers transiting Canadian waters.

This development, along with the steady rise of tanker movements around the world, has raised questions about the opportunities and risks for coastal and Indigenous communities, the environment and the economy.

This site was created by Clear Seas Centre for Responsible Marine Shipping, an independent research centre that promotes safe and sustainable marine shipping in Canada.

The site’s purpose is to share objective information about oil tankers in Canadian waters, and to encourage informed conversations about marine shipping.

Oil Tankers 101

Since the late 19th century, oil tankers have been used to transport large amounts of oil across oceans and waterways. Today roughly 60% of all oil transported around the world travels by tanker.

Tanker Sizes and Capacities

230m Max DWT 80,000
245m Max DWT 120,000
285m Max DWT 200,000
330m Max DWT 320,000
415m Max DWT 550,000

An oil tanker's capacity is measured based on its size in deadweight tonnes (DWT), which is the total weight a ship can safely carry (including the cargo, fuel, crew, provisions, etc.) not including the weight of the ship itself. Tanker capacities can range from a few thousand DWT to 550,000 DWT.

How to Spot a Tanker

Tankers are easily identifiable
Oil Tanker
  • Transports oil, refined or unrefined
  • Piping visible on deck
  • No large cranes visible
Container Ship
  • Transports standard-sized shipping containers
  • Containers stacked visibly above deck
  • Large crane visible
Roll-on/Roll-off (RORO) Ship
  • Transports wheeled cargo, such as cars, trucks and railway cars
  • Sits high above the water
  • Multiple vehicle decks
Bulk Carrier
  • Transports unpackaged cargo, such as coal, grain and iron ore
  • Large hatches visible on deck
  • Can have large cranes visible

Tankers in Canadian Waters

Crude oil and petroleum products are the largest commodities handled by Canadian ports, representing over 20% of total tonnage.

Transport Canada estimates that there are approximately 20,000 oil tanker movements off the coasts of Canada each year. Of these, approximately 17,000 (85%) are on the Atlantic coast. Most of the oil tanker movements in Canada take place at 7 ports and facilities.

Canadian Ports and Facilities that Handle Most Oil Tankers

Map of Canada
Vancouver, BC
Quebec City, QC
Montreal, QC
Come by Chance, NF
Newfoundland Offshore
Port Hawkesbury, NS
Saint John, NB
Vancouver, BC
Quebec City, QC
Montreal, QC
Come by Chance, NF
Newfoundland Offshore
Port Hawkesbury, NS
Saint John, NB

The largest tankers transiting Canadian waters are Ultra-Large Crude Carriers (ULCC) (350,000 – 550,000 DWT), which transit the east coast of Canada. ULCCs are the largest tankers in the world and they can carry up to 4 million barrels of oil.

On the west coast the largest tankers that are used to ship oil out of the Port of Vancouver are Aframax tankers (80,000 – 120,000 DWT). They can carry approximately 550,000 barrels of oil.

Crude oil is not currently transported as shipping cargo in the Arctic. However, small amounts of refined oil cargo are carried in order to supply Canada’s Arctic communities with vital fuel. Between 2002 and 2011, ~0.18% of all refined oil transported as cargo in Canadian waters transited the Arctic. In the coming years, increases in the number of tankers transporting both crude and refined oil cargo through the Arctic are expected as sea-ice melts and opens shipping lanes in the region.

Oil Transported as Cargo in Canadian Waters by Region

Pacific Coast

Canadian Traffic 6MT
US Traffic Through Canadian Waters 37MT

Atlantic Coast

Great Lakes, St. Lawrence Seaway 24MT
Estuary and Gulf of St. Lawrence 67MT
Atlantic Coast 192MT

*MT = millions of tonnes The vast majority of tanker movements occur on the Atlantic coast.

Tankers currently represent about 2% of total ship traffic visiting the Port of Vancouver (out of 250 total vessels per month, about 5 are tankers). The Government of Canada’s recent approval of the Trans Mountain Expansion Project is expected to increase the number of tankers visiting the Port of Vancouver from around 5 to around 34 per month. In this scenario, tankers would represent about 14% of total ship traffic.


of all tanker movements in Canada currently take place on the Atlantic coast

4 million

barrels is how much oil the largest tankers in the world can carry


of total tonnage handled at Canadian ports is crude oil and petroleum products

Incidents, Accidents and Spills

According to a recent Angus Reid Institute Poll commissioned by Clear Seas, a majority of Canadians (67%) are concerned about the potential for oil spills in Canadian waters.

While tankers carry unrefined crude oil and refined petroleum products that we benefit from using every day (such as gasoline, jet fuel, diesel and asphalt) they also carry risks – including the potential for spills.

Marine oil spills can occur when vessels are involved in accidents or incidents. The most common types of accidents and incidents that lead to major ship-source oil spills include groundings, collisions, allisions (when a ship strikes a stationary object), and hull and equipment failures.

The risks associated with marine oil spills are not limited to oil tankers – all vessels that use oil-based products as fuel pose some risk of an oil spill. When oil-based products are discharged from any type of commercial vessel it is known as a ship-source oil spill.

The consequences of large-scale oil spills on wildlife, ecosystems, coastal and Indigenous communities and local economies can be significant.

While there is justifiable concern for the potential of an oil spill, the volume and frequency of oil spills has been decreasing globally since the 1970s.

Incidence of Spills Worldwide 1970 - 2015

  • Seaborne Oil Trade (Billion Tonne-miles)
  • No. of Spills 7 Tonnes and Over

A report sponsored by Clear Seas, Commercial Marine Shipping Accidents: Understanding the Risks in Canada, identified that large oil spills, especially those from oil tankers, have been rare in Canadian waters.

Tanker safety has improved with new regulations, more robust ship design codes, enhanced emergency preparedness and response systems, and better self-regulation and procedures. These developments have coincided with a notable drop in marine shipping accidents worldwide and in Canada, as well as fewer oil spills.

Clear Seas’ report determined the following statistics related to ship-source oil spills in Canadian waters for the years 2003 to 2012:

Annual Canadian Oil Spill Frequency (2003 – 2012)

Average Number of Spills Spill Size in Litres
~48 100 to 10,000*
2.5 10,000 to 100,000
0.7 100,000 to 1,000,000
0 >1,000,000**
The volume of a standard hot tub is approximately 1,600 litres
** Approximately 40% of the volume of an Olympic swimming pool

Overall, 67% of ship-source oil spills in Canadian waters from 2003 to 2012 were between 100 and 1,000 litres. Of the larger spills (those 10,000 litres or greater), 78% involved fuel oil rather than oil being carried as cargo. As such, oil tanker cargo was not the source of most of these spill.

History of Notable Ship-source Oil Spills in Canada

Spill Size in Litres Year Ship, Ship Type, Location, Incident Type
10,000,000 '70 SS Arrow, Tanker, Nova Scotia, Grounding
464,000 '74 Golden Robin, Tanker, Quebec, Bunkering Spill
9,280,000 '79 Kurdistan, Tanker, Nova Scotia, Allision
874,430 '88 Nestucca, Fuel Barge, Washington U.S. & British Columbia, Collision
290,000 '89 Nancy Orr Gaucher, Tanker, Ontario, Bunkering Spill
232,000 '90 Rio Orinoco, Tanker, Quebec, Grounding
23,000 '98 MV Saraband, Tanker, Quebec, Leak
170,000 '04 Terra Nova, Floating Production Storage and Offloading, Newfoundland, Mechanical Failure
230,000 '06 Queen of the North, RORO Ferry, British Columbia, Grounding
2,700 '15 MV Marathassa, Bulk Carrier, British Columbia, Leak
110,000 '16 Nathan E. Stewart, Tug Boat, British Columbia, Grounding
*Spill sizes have been estimated to the best of responders' abilities **For comparison, the size of the Exxon Valdez oil spill was ~40,882,450 litres

of global maritime trade is oil and gas shipments


of oil spills in Canadian waters from 2003 - 2012 were between 100 and 1,000L in size


of the world's oil is transported by tankers

Spill Prevention and Response

Canada has the longest coastline in the world and Canadians are rightly concerned about protecting it.

Spill Prevention

Preventing shipping accidents, incidents and oil spills is a shared responsibility among international, national, provincial and local bodies, and ship owners and operators. Working together, the following measures are aimed at preventing accidents and spills in Canadian waters.

Marine Pilots

These licensed Canadian navigational experts conduct tankers and other ships in harbours and busy waterways.

Learn more.
Mandatory Double Hulls

All tankers must have 2 watertight layers on the bottom and sides of ships. The double layer construction helps in reducing the risks of marine pollution in the event of damage to the ship's hull.

Learn more.
Navigational Aids

Navigating Canadian waters is made safer using visual, auditory and electronic aids that warn of obstructions and mark shipping routes.

Learn more.
Marine Inspections

Transport Canada regularly deploys marine inspectors to ensure tankers transiting Canadian waters are in safe operating condition and that every tanker operating in Canada has a double hull. The Government of Canada requires that all Canadian tankers be inspected once a year and that all foreign tankers be inspected on their first visit to Canada and at least once a year afterward.

Learn more.
Tug Escorts

In designated areas, tug boats escort loaded tankers and aid both incoming and outgoing vessels - they can slow, stop or steer a vessel if it loses power or its steering system.

Learn more.

Spill Response

While minimizing risks through prevention measures is critical – what happens if a spill does occur?

The response to an oil spill influences the spill’s impact – and can avoid or reduce negative environmental, social, economic and health impacts.

The way that Canada responds to a spill involves a combination of industry-led initiatives and government regulation and oversight. Industry – whose activities create the risk – bears financial responsibility to prepare for and respond to spills. In Canada, industry is required to do so through 4 industry-funded and government-certified response organizations which are prepared to respond to spills.

Simply stated – if a tanker is headed to a Canadian port, the shipowner must have an agreement with a response organization before entering Canadian waters. In the event of a spill, the polluter is, by law, required to pay for the cost of clean-up

Unlike the south, there are no certified response organizations for Arctic spills. Preparedness in the Arctic requires ship and oil handling facility owners to identify – in their respective spill response plans – the resources they would employ to respond to a spill.

Canada’s Marine Oil Spill Response Organizations

  • Western Canada Marine Response Corporation (WCMRC)
  • Eastern Canada Response Corporation (ECRC)
  • Point Tupper Marine Services (PTMS)
  • Atlantic Environmental Response Team (ALERT)

The Canadian government delivers the legislation and regulation for the spill response regime and oversees industry's preparedness and actions during a spill. Transport Canada provides the government's legislative and regulatory mandate while the Canadian Coast Guard is tasked with overseeing the response to the spill as the "on-scene commander."

Liability and Compensation – “The Polluter Pays”

How is the clean-up paid for and who pays for the costs?

When a spill from a tanker occurs in Canada, there are different sources of compensation from international and domestic funds. Combined, they could provide up to $1.55 billion for a single oil spill.

Shipowners' Liability for Spills

International conventions make shipowners liable for oil spills from tankers. Liability depends on the size of the ship, and must be backed by the shipowners' mandatory insurance. Learn more.

The Ship-Source Oil Pollution Fund

This Canadian fund was created from levies collected from oil cargo companies. It addresses spills of any type of oil from any type of ship – not just tankers. Changes made to the SOPF in December 2018 removed the per-incident limit of liability; there is effectively no limit to compensation available from the SOPF. Learn more.

International Oil Pollution Compensation Funds

Canada is a member of the International Oil Pollution Compensation Funds which administers 2 international funds created from levies collected from oil cargo companies. Learn more.

Oceans Protection Plan

In November 2016, Prime Minister Trudeau announced a $1.5 billion investment aimed at strengthening the protection of Canada’s coasts through improved marine safety measures. Among relevant measures, the plan includes investments in oil spill response, a moratorium on crude oil tankers on British Columbia’s north coast and enhanced resources for the Canadian Coast Guard. Learn more.


of tankers must have double hulls

243,000 km

the length of Canada's coastline; the longest in the world


compensation is available if a tanker oil spill occurs in Canada

Learn more at clearseas.org/tankers

About Clear Seas

Clear Seas Centre for Responsible Marine Shipping is an independent research centre that promotes safe and sustainable marine shipping in Canada.

Clear Seas was established in 2014 after extensive discussions among government, industry, environmental organizations, Indigenous peoples and coastal communities revealed a need for impartial information about the Canadian marine shipping industry.

Clear Seas received seed funding in 2015 through equal contributions from the Government of Canada (Transport Canada), the Government of Alberta (Alberta Energy) and the Canadian Association of Petroleum Producers. Our funders saw the need for an independent organization that would be a source of objective information on issues related to marine shipping in Canada.

As an independent research centre, Clear Seas operates at arm’s length from our funders. Our research agenda is defined internally in response to current issues, reviewed by our research advisory committee, and approved by our board of directors.

Our board of directors is composed of scientists, community leaders, engineers and industry executives with decades of experience investigating human, environmental and economic issues related to our oceans, coastlines and waterways.

Our reports and findings are available to the public at clearseas.org/en

Sources & Citations