Marine oil spills

Number of marine oil spills

Canada experiences many small (less than 10 litres) marine oil spills incidents each year, most of which come from operating and maintaining personal watercraft or releases from sunken vessels. Large and catastrophic marine oil spills are responsible for substantially higher volumes of oil being released to the environment but occur much less frequently.

Key results

In 2024,^{Footnote 1}  

• Nineteen (19) marine oil spills with a volume of more than 10 litres were detected by the National Aerial Surveillance Program
• the National Environmental Emergencies Centre received 1 009 reports of marine oil spills across Canada, 212 of which had an estimated volume of less than 10 litres and 575 an unknown quantity or an estimated volume of less than 10 litres
• Four hundred and twelve (412), or 40.8%, of marine oil spills reported to the National Environmental Emergencies Centre were related to water transportation such as pleasure craft and fishing vessels

Number of marine oil spills detected by the National Aerial Surveillance Program, Canada, 2010 to 2024

Note: Beginning in 2021 the National Aerial Surveillance Program changed the way they report marine oil spills detected during their sorties such that the program only reports back on large spills above 10 litres. Year refers to fiscal year, which runs from April 1 to March 31. For example, the year 2024 therefore refers to April 1, 2023 to March 31, 2024.
Source: Transport Canada (2024) Marine Safety and Security Directorate.

In 2024, the sorties flown by the NASP observed and reported 19 marine oil spills of a volume greater than 10 litres, for a total estimated volume of 739 litres (see the location section to see the location of spills). As a comparison, 10 litres is less than 1 24-pack of 500ml water bottles.

Number of marine oil spills by volume reported to the National Environmental Emergencies Centre, Canada, 2019 to 2024

Note: Year refers to fiscal year, which runs from April 1 to March 31. For example, the year 2024 therefore refers to April 1, 2023 to March 31, 2024. The volume of spills reported to the National Environmental Emergencies Centre at Environment and Climate Change Canada are based on the subjective estimates made by the individual person or entity making the report.
Source: Environment and Climate Change Canada (2024) National Environmental Emergencies Centre.

The National Environmental Emergencies Centre (NEEC) works directly with people in Canada, such as private citizens, enterprises, or community groups, as well as having partnership agreements with certain federal departments as well as provincial and territorial governments to capture and track pollutant releases across Canada. In 2024, the NEEC received nearly 10 500 reports of pollutants being released and impacting the environment, of which 1 009 were to the marine environment involving at least one type of oil product. The majority, 575, of incidents with reporter‑estimated volumes had an unknown quantity, 212 were under 10 litres, 115 were between 10 and 100 litres, and 107 had volumes more than 100 litres.

The volumes reported to NEEC represent the estimated volume that has been or could potentially be released to the environment at the time of reporting. Based on the information provided in the report, if there is a significant threat to the health of Canadians or the environment from a spill or the potential of one, the incident is escalated to the emergency operations centre for action.

In 2024, 261 of the 1 009 incidents of potential oil-related spills impacting the marine environment were escalated for additional assessment and to ensure that all reasonable measures were being taken to protect the environment and human health. Fifty-four (54) incidents resulted in specific communication with senior management (Heads-up). 40 incidents resulted in services and scientific information being provided to the agency leading the response to inform decisions about appropriate response measures and operations (Advisory). These services and scientific information include sensitivity maps, dispersion, drift or trajectory models, special weather forecasts, and fate and behaviour science. Finally, 7 incidents resulted in on-site deployments of environmental emergency officers to support the agency leading the response to the incident.

While reporter-based volume estimations and characterisations may be subjective and not consistent, reporting and tracking incidents of oil spills to Canada’s marine environment remains important.

Category of marine oil-spill incident as reported to the National Environmental Emergencies Centre, Canada, 2024

Note: Year refers to fiscal year, which runs from April 1 to March 31. For example, the year 2024 therefore refers to April 1, 2023 to March 31, 2024. The categorisation of spills reported to the National Environmental Emergencies Centre at Environment and Climate Change Canada are based on the subjective rationale made by the individual person or entity making the report.  "Other water transportation” consist of Port and harbour operations, Barge, Ferry, Bulk carrier, Cargo/Container, Marine cargo handling, Marine Tanker and Other water transportation. “Other” consist of Industrial facility, Residential/Private, Electric power generation, transmission and distribution, Other facilities/services, Manufacturing, Retail trade, Agriculture, forestry, fishing and hunting, Mining and quarrying (except oil and gas), Oil and gas extraction, Water, sewage and other systems, Waste management and remediation services, Arts, entertainment and recreation, Habitat disturbance/destruction, and Warehousing and storage (commercial) facilities. NOS refers to marine vessels transporting “Not Otherwise Specified” dangerous goods. 
Source: Environment and Climate Change Canada (2024) National Environmental Emergencies Centre.

Of the 1 009 spills reported to the NEEC in 2024, 412 (40.8%) were related to water transportation. Of the 412 water transportation incidents, pleasure crafts, marine vessel, and fishing vessels represented the largest portion (approximately 78%). Another approximately 6% of the spills were attributed to port and marina operations.

Location marine oil spills 

The majority of marine oil spill incidents occur in places where there are more boats – in Canada’s coastal waters. 

Key results

In 2024,^{Footnote 1} 

• Ten (10) of the 19 spills detected by aerial surveillance were in British Columbia and 8 took place in the Atlantic provinces and Quebec.
• The majority, 96% (708 litres) of the total estimated volume was detected in coastal areas^{Footnote 2} , while the other 4% (31 litres) detected came from offshore oil spills

Location of marine oil spills of over 10 litres detected by the National Aerial Surveillance Program, Canada, 2024

Note: Year refers to fiscal year, which runs from April 1 to March 31. For example, the year 2024 therefore refers to April 1, 2023 to March 31, 2024. At this level of zoom two spills overlap in the Burleith Arm.
Source: Transport Canada (2024) Marine Safety and Security Directorate.

In 2024, the 19 marine oil spills reported by the National Aerial Surveillance Program totaled an estimated volume of 739 litres. Fifteen (15) of the spills were from unknown sources, which represents 88% of the total volume spilled that year. The other 4 spills were from suspected sources, which represent 12% of the total volume spilled. The suspected sources of these spills are from an oil platform and sunken vessels. The source of an oil spill is considered "suspected" when the spill can be linked or suspected of coming from a vessel at the time of observation. If not, the source is defined as unknown.

Volume of marine oil spills detected offshore and in coastal areas by the National Aerial Surveillance Program, Canada, 2010 to 2024

Note: For the years 2021 and on, only spills over 10 litres are reported. Year refers to fiscal year, which runs from April 1 to March 31. For example, the year 2024 therefore refers to April 1, 2023 to March 31, 2024.
Source: Transport Canada (2024) Marine Safety and Security Directorate.

In 2024, 96% (708 litres) of the total estimated volume was detected in coastal areas, while the other 4% (31 litres) detected came from offshore oil spills. In 2021, just 3 separate spills amounted to 11 800 litres of oil spilled, which represents 67% of the total volume reported (17 651 litres) that year. Accidents involving large oil tankers make up most of the volume of oil spilled when they do occur. For example, in 2018, Cenovus Energy was responsible for an estimated 250 000 litres oil spill off the coast of Newfoundland and Labrador, the largest oil spill in the province’s history.^{Footnote 3 Footnote 4}  It is estimated that a catastrophic marine oil spill of over 10 000 000 litres can be expected approximately every 242 years.^{Footnote 5 Footnote 6}   

Canadian crude oil is transported by pipeline, tanker, and rail. The use of tankers as a means of transporting oil is greater in the Atlantic provinces, and the largest marine oil spills in Canada’s waters have occurred there. While crude oil production and trade has increased, the proportion of oil transported by tanker in the 2016 to 2022 period has remained between 6% and 8%.^{Footnote 7} 

About the indicator

What the indicator measures

The indicator reports the volume and frequency of reported or observed oil spills to Canada’s marine environment from 2010 to 2024. 

Why this indicator is important

Canada’s coastline measures an estimated 243 042 km across the Pacific Ocean, Arctic Ocean, and Atlantic Ocean. It is made up of a diverse array of marine environments which include estuaries, rocky shores, salt marshes, kelp forests, mud flats, eelgrass meadows, and land-attached sea ice.

Oil spills can lead to the degradation and loss of coastal habitats and can inflict significant harm to wildlife populations. Sea birds are the animals most impacted by oil spills to the marine environment. These birds come in direct contract with oil spills and slicks as they move throughout their habitats and where they feed. When their outer feathers become contaminated with oil, these feathers lose their waterproofing and ability to help the birds regulate their temperature. As birds preen and feed after oil spills, they ingest the oil which can go on to have knock-on health effects. Surface oil following a spill can also impacts cetaceans (whales and dolphins) and pinnipeds (sea lions) as they surface to breathe or feed, through ingestion or contamination that impairs temperature regulation, mobility, sight, or added stress due to being covered in oil.^{Footnote 8}

Oil spills also impact Canadian communities. Coastal communities touched by a spill can see many of their businesses and leisure grounds closed until a cleanup is completed. Local commercial and recreational fishing can be impacted through the damage to fish populations and environmental stress related to the spill. Marinas, harbours, and waterways can be shut down, as well as beaches and parks. Depending on the nature of the incident leading to the spill, lives and livelihoods may also be lost, with impacts on the broader communities hurt by the oil spill. 

Negative effects can continue even after the initial incident of an oil spill; for example, sunken vessels can continue to impact marine environments years later. Each oil spill is different, and the unique factors of the situation will impact the severity of the spill and the required response to it.^{Footnote 9} 

Related initiatives

For 30 years, the Ship-source Oil Pollution Fund (SOPF) has been mandated to compensate victims of oil pollution damage, including costs incurred for preventive measures, caused by ships and then take action to recover the costs from the polluters or other responsible parties. The fund provides compensation for oil pollution damage caused by any type of oil spill from any type of vessel, even when the cause of the spill is not known. Once a claim is assessed and paid, the Administrator of the fund is required to take all reasonable steps to recover compensation from the polluter. These recovered amounts go back into the fund’s accounts and help make sure that industry-funded compensation is available in the event of future spills.^{Footnote 10}  

Liability and compensation for SOPF in Canada is based on international conventions developed by the International Maritime Organization which tries to make sure the polluter pays. The SOPF provides compensation for oil pollution damage caused by any type of oil spill from any type of vessel, even when the cause of the spill is not known. 

In 2024, 41 claims for compensation were made worth a total of $9,269,433. Most of these claims came from British Columbia. Quebec saw an increase in the number of claims in 2024 to 32% of total claims. The SOPF was able to recover funds from polluters in 9 files, recovering a total of $291,145. 93% of the claims were submitted by the Canadian Coast Guard to recoup the costs incurred for responding to and addressing oil-spill-related incidents.^{Footnote 11}

Related indicators

The Releases of harmful substances to water indicator tracks facility-based releases to water of 3 substances that are defined as toxic under the Canadian Environmental Protection Act, 1999: mercury, lead and cadmium and their compounds. For each substance, data are provided at the national, regional (provincial and territorial) and facility level and by source.

Data sources and methods

Data sources

This indicator presents data from 2 sources within the Government of Canada, the Transport Canada’s National Aerial Surveillance Program (NASP) and Environment and Climate Change Canada’s National Environmental Emergencies Centre (NEEC).

The NASP patrols over waters under Canadian jurisdiction to detect pollution resulting from ship operations, intentional dumping and accidents. Evidence gathered by the program is used to enforce legislation applicable to illegal discharges from ships. The data are collected for enforcement and deterrence purposes and are focused on commercial vessels. As a result, not all marine pollution spills are accounted for in this indicator.

The NEEC is the Government of Canada’s coordination hub for scientific support during environmental emergencies including bringing together scientific and technical advice for cleaning up hazardous material spills in all environments, organizing emergency preparedness and response activities to assist on-the-ground responders, and providing specialized services and information such as localized weather reports, spill modelling, clean-up advice.

Methods

The National Aerial Surveillance Program (NASP) provides data on the number of spills observed annually as well as a spill counts and the corresponding estimated volumes for each spill. Spill volumes are estimated by multiplying the area of the slick by its varying thickness. An airborne maritime surveillance system (MSS6000) calculates the area of a slick (the film or layer of oil floating on water, specifically one that has leaked or been discharged from a ship) based on a polygon drawn manually by the surveillance officer around the oil observed on the remote sensed imagery of the ocean surface. Surveillance officers estimate the oil thickness by assessing the visual characteristics of the oil slick to determine the varying thicknesses in the slick and apply a formula to calculate the volume (see More information).

Data used from the National Environmental Emergencies Centre (NEEC) in this indicator has been selected from the database of reported incidents based on their categorization by the individual reporting the incident as having an impact of freshwater, saltwater, marine, or estuary. The database query was further refined to include of reported spills of hydrocarbons (see the list of reported hydrocarbons under more information).

Recent changes

This version of the indicator adds data on oil spills to the marine environment from Environment and Climate Change Canada’s National Environmental Emergencies Centre reported under the Canadian Environmental Protection Act 1999 Schedule 1: List of Toxic Substances.

Caveats and limitations

The indicator provides the volume detected by the National Aerial Surveillance Program (NASP). The data are collected for enforcement and deterrence purposes and are focused on commercial vessels. As a result, not all marine oil spills are accounted for in this indicator. In addition, for the year 2021 and beyond, NASP reports only the spills exceeding a volume of 10 litres. The volume of spills detected was not corrected for surveillance effort, as there is no way to differentiate the chance of detecting a large or small spill in a given hour of surveillance. Major accidents can cause large variations in the volume of spills each year, making it difficult to detect annual trends.

The indicator also includes reported incidents of marine oil spills reported to the National Environmental Emergencies Centre. While NASP sorties and the reported incidents can potentially capture the same incidents, marine oil spills in Canadian waters, data presented in this indicator do not equate the methods used or link the reported incidents. 

Resources

References

Canadian Energy Regulator (2024) Crude Oil Export Summary.  Retrieved on August 21, 2024.

CBC News (2024) Cenovus slapped with $2.5M fine for 2018 offshore oil spill. Retrieved on September 25, 2024.

Environment and Climate Change Canada (2021) A field guide to oil spill response on freshwater shorelines: chapter 4. 

Environment Canada (1996) Fate and Effects of Marine Oil Spills (PDF; 905 KB). Retrieved on September 11, 2024.

Ship and Rail Compensation Canada (2024) Annual Reports. Retrieved on November 19, 2024.

Statistics Canada (2016) International perspective. Retrieved on September 10, 2024.

Transport Canada (2024) Marine liability and compensation: oil spills. Retrieved on September 25, 2024.

Transport Canada (2019) Report to Parliament 2011-2016 – Ship-Source Oil Spill Preparedness and Response Regime – TP 15418. Retrieved on October 15, 2024.

WSP Canada Inc. (2014) Risk Assessment for Marine Spills in Canadian Waters Phase 1, Oil Spills South of the 60th Parallel (PDF; 21.2 MB). Retrieved on January 20, 2025.

Related information

Environmental Response Systems

How Canada Responds to Ship-Source Oil Spills

International Convention for the Prevention of Pollution from Ships (MARPOL)

International Convention on Oil Pollution Preparedness, Response and Cooperation (OPRC)

National Aerial Surveillance Program

National Environmental Emergencies

National Oil Spill Preparedness and Response Regime

Pollution emergencies