Underwater Noise and Marine Mammals #clearfacts #underwaternoise #marinemammals


Each day, Canadians benefit from commercial marine shipping. However, these activities which we rely upon for global trade, take place across many complex ecosystems that are home to at-risk marine life such as whales.

With increased marine traffic in Canada’s coastal waters comes an increase in underwater noise from vessels – and a need to understand the impacts on marine mammals who use sound to communicate, feed, navigate and reproduce.

This site’s purpose is to share objective information about the impact of underwater noise from marine traffic on marine mammals – in particular on whales, and to encourage informed conversations about the issue.

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.

Marine mammals and underwater noise

Imagine you live in a dark place and you must rely on your hearing the same way you would rely on your vision.

And that space is loud and getting louder.

It’s certain to cause you stress.

Sound is critical to the survival of many marine animals and it is widely recognized that underwater noise has both short-term and long-term impacts on marine life.

How a marine mammal responds to underwater noise is complex and depends on a number of factors including:

  • Age
  • Sex
  • Hearing sensitivity
  • Behavioural state
  • Presence of offspring
  • Proximity to shoreline

Underwater noise can negatively affect the ability of marine mammals to:

  • Find prey
  • Avoid danger
  • Communicate
  • Rest
  • Reproduce
  • Navigate

Underwater noise can negatively affect marine mammals, resulting in:

  • Changed behaviours
  • Hearing loss
  • Increased stress levels
  • Displacement to quieter waters
  • Injury or death

Underwater noise

Sounds in the ocean come from both natural and human-made sources.

Sound describes the effect a vibrating object has on its surrounding environment. Underwater sound is generated by a variety of natural sources, such as breaking waves, rain, under sea volcanoes, hydrothermal vents and marine life. It is also generated by a number of human-made (anthropogenic) sources, including ships, seismic surveys and sonars.

Primary Sources of Underwater Sound

Natural Sources

Rain - Clear Seas
Storms - Clear Seas
Cracking ice - Clear Seas
Cracking ice
Marine life - Clear Seas
Marine life
Surface waves - Clear Seas
Surface waves
Earthquakes - Clear Seas
Hydrothermal vents - Clear Seas
Hydrothermal vents

Human-made Sources

Commercial vessels - Clear Seas
Commercial vessels
Recreational vessels - Clear Seas
Recreational vessels
Pile driving - Clear Seas
Pile driving
Sonar - Clear Seas
Seismic surveys - Clear Seas
Seismic surveys
Snowmobile on ice - Clear Seas
Snowmobile on ice

Underwater noise from marine shipping

Commercial marine shipping is one of the main sources of human-made underwater sound and shipping’s contributions to underwater noise have been increasing.

Ships and other motorized vessels produce a diverse range of sound frequencies which overlap with the frequencies used by whales and other marine mammals to communicate, feed, navigate and reproduce. Vessel noise is particularly chronic and loud in coastal areas near active shipping lanes, ferry routes and ports.

There are two main sources of noise from ships:

Propellers - Clear Seas


Noise is emitted when the low pressure generated by the propeller causes thousands of tiny bubbles to form. When they collapse, the sound made is a major source of noise. Known as "cavitation", it can account for 80-85% of the noise from a ship.

Machinery - Clear Seas


Diesel engines are a significant source of noise because of the vibrations that radiate through the ship’s hull.

Vessels radiate different levels of noise depending on the vessel type, ship design, how well the hull and propeller are maintained, ship speed and other factors.

Vessel noise and whales

Ships produce noise at frequencies ranging from 20 to 100,000 Hertz. This noise overlaps with the frequencies used by whales and other marine mammals to communicate, feed, navigate and reproduce.

Listen to what it sounds like when a ship passes a pod of orcas

Learn more about three whale populations found in Canada that are endangered and impacted by underwater noise.

Southern Resident Killer Whale – Salish Sea

  • With a population of 78 (January 2017) the Southern Resident killer whale species is considered to be endangered
  • Southern Resident killer whale habitat overlaps with busy commercial shipping lanes and ferry routes
  • Underwater noise from existing marine traffic in the Salish Sea is disruptive to the Southern Resident killer whale’s ability to hunt, navigate and communicate
  • The Government of Canada has identified underwater noise as a key threat to the recovery of the Southern Resident killer whales
  • Measures are being examined to reduce or minimize these disturbances (for an example see the Haro Strait Vessel Slow-down Trial, below)

North Atlantic Right Whale – Atlantic Canada

  • The North Atlantic right whale is considered one of the world’s most endangered whale populations
  • Historically, the species gets its name from the whaling industry when whalers considered them the “right” whale to hunt
  • Today, threatened by ship collisions, entanglements in fishing nets and underwater noise, the right whale population is estimated to be close to 500
  • In 2003, the Government of Canada moved shipping lanes in the Bay of Fundy in an attempt to reduce ship strikes
  • In an effort to reduce the risk of ship strikes to the NARW, the Government of Canada has instituted seasonal speed restrictions in sections of the Gulf of St-Lawrence. Learn more

Beluga Whale – St. Lawrence Estuary

  • Although belugas are typically found in the Arctic, the St. Lawrence Estuary is home to the most southern population of these animals - also known as "white whales"
  • Considered to be endangered the population is estimated to have fewer than 1,000 individuals today
  • A number of factors impact this population including habitat loss, finite food sources and noise disturbances from human activity like boating, whale watching and shipping
  • Belugas, being very vocal animals are frequently called "canaries of the sea"

Critical habitat of whales overlaps with major shipping routes in Canada

Critical habitat is defined by Fisheries and Oceans Canada as the habitat that is deemed necessary for an at-risk species' survival or recovery. The full range of a species’ habitat is often larger than the critical habitat.

Canadian Map - Clear Seas
Quebec City
Saint John
Southern Resident Killer Whale
St. Lawrence Beluga Whale
North Atlantic Right Whale

Preventing and mitigating vessel noise impacts

The issue of underwater noise in Canada has been considered for many years and yet, assessing how vessel noise impacts marine mammals and how they can be protected remains very complex.

While there is consensus that underwater noise impacts marine mammals, there are still gaps in our understanding of the issue and how to best mitigate it. For example, how do you determine how much of the sound from vessels reaches animals directly, or how much noise is too much for a given species?

The variables that must be considered are almost limitless – from the salinity, temperature and depth of the water, to the conditions present at the ocean floor to the type of noise. Also, data gathered from one area and one species cannot necessarily be transferred to another location or another species.

Cumulative impacts must also be taken into account. On its own, underwater noise may pose a threat – but what happens when it is combined with other stressors like food shortages or pollution? How do you separate noise from other human pressures on the marine environment?

We still have a lot to learn about the effects of vessel noise on marine mammals, but there are strong indications that it is a significant stressor that could be affecting their chance of survival. And so, we need to take precautions now. – Honourable Marc Garneau, Minister of Transport, May 3, 2017

There are ways for vessel owners and operators to reduce ship noise:

Slow down

Operate below the cavitation speed and avoid rapid acceleration


Maintain clean hulls and propellers to reduce cavitation


Plan a new route when in the immediate vicinity of whales or other sensitive areas


Incorporate quieting techniques when new vessels are built

There are a number of initiatives currently in place in Canada that are helping to prevent and mitigate the impacts of vessel noise on marine mammals. Here are some examples:

Haro Strait Vessel Slowdown Trial, The ECHO Program and Port of Vancouver

  • Building on a 2016 analysis of regional ocean noise contributors, this trial aims to understand the relationship between vessel speed, underwater noise and the predicted effects on endangered Southern Resident killer whales in an important summer feeding area
  • Between August 7 and October 6, 2017 all commercial vessels transiting Haro Strait are asked to slow down to 11 knots
  • Average speeds in this area currently range from 18 knots for container vessels to 13 knots for bulk carriers
  • The slowdown could introduce delays of between 30 minutes to an hour depending on conditions and vessel type
  • Nearly 70 vessel operators, companies and organizations have voluntarily committed to participate in or support the trial (August 2017)
  • Hydrophones will provide data, and computer modelling will be used to simulate the effects on killer whale behaviour
  • The analysis from this trial will help determine implications of slowing vessels down in Southern Resident killer whale habitat
  • The ECHO program has also conducted a study on vessel quieting design, technology and maintenance options which resulted in the introduction of Eco Action incentives for quieter vessels.
Learn more

Performance Indicators for Underwater Noise, Green Marine Environmental Certification Program

  • In early 2017, Green Marine introduced two new performance indicators dealing with underwater noise emanating from ships and port activities respectively, with the goal of reducing the impact on marine mammals
  • Starting in 2018, ports and ship owners operating in saltwater will need to meet the underwater noise indicators’ criteria to earn their certification
  • These new indicators will encourage the maritime industry to work in collaboration with the scientific community to collect data on its noise emissions, which will be used to further develop strategies for noise reduction
Learn more

Green Wave Environmental Incentive Program, Port of Prince Rupert

  • Recently, the Port of Prince Rupert's Green Wave program added criteria for underwater noise
  • The Port of Prince Rupert is one of the first ports to implement incentives for quieter vessels through reduced harbour dues
Learn more

Impacts of Rerouting Marine Traffic in the St. Lawrence Estuary, Government of Canada

  • In 2014, Fisheries and Oceans Canada examined marine traffic exposure of St. Lawrence Estuary beluga under actual and proposed commercial shipping routes to determine effects on this whale population
  • The study found that rerouting marine traffic from the North to South Channel of the St. Lawrence Estuary would increase the vessel noise exposure of female and juvenile belugas important to the recovery of this endangered species
  • The study recommended that maintaining the major vessel route in the North Channel would minimize impacts on this beluga population
Learn more

Guidelines to Reduce Underwater Noise from Commercial Ships, International Maritime Organization

  • In 2014, the International Maritime Organization (IMO) adopted guidelines to reduce underwater noise from commercial ships
  • The guidelines provide advice for designing quieter ships and for reducing noise from existing ships
  • The guidelines also advise owners and operators on how to minimize noise through ship operations and maintenance
Learn more

Research in progress

Currently in Canada, government agencies, universities, industry, Indigenous communities and non-governmental organizations are working to understand underwater noise and its impacts on marine life.

Government of Canada – As part of the $1.5 billion Oceans Protection Plan, new protections for whales and a commitment to better understand the cumulative effects of shipping on marine mammals such as the Southern Resident Killer Whales, belugas and North Atlantic right whales were announced in November 2016. Work is underway to establish baselines for underwater noise and how to mitigate those effects.

Learn more

Ocean Networks Canada – Ocean Networks Canada monitors the east and west coasts of Canada to continuously deliver data in real-time to support evidence-based decision-making on ocean management, disaster mitigation and environmental protection. ONC’s hydrophones and listening stations listen live and archive sound in the ocean from Vancouver to Cambridge Bay, Nunavut.

Learn more

MEOPAR – The Marine Environmental Observation Prediction and Response Network (MEOPAR) is involved in several projects related to underwater noise, including the NEMES project that is modeling ship movements to predict the exposure of animals to vessel noise, the WHaLE project (Whales, Habitat and Listening Experiment) to give better information on whale locations to mariners on the Atlantic and Pacific coasts, and building a Marine Mammal and Maritime Traffic Simulator for the St. Lawrence Estuary.

Learn more

A number of other research projects and initiatives on underwater noise and its impacts on marine life are underway at Canadian institutions, including work at Fisheries and Oceans Canada, Transport Canada, The Royal Canadian Navy, Ocean Frontier Institute, Port of Vancouver and the ECHO Program, World Wildlife Fund Canada, Vancouver Aquarium, Wildlife Conservation Society of Canada, and Eastern Charlotte Waterways, among others.

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

  1. Council of Canadian Academies. (2017). The Value of Commercial Marine Shipping to Canada.
  2. Hildebrand, J. A. (2005). Impacts of anthropogenic sound. In J. E. Reynolds III, (Ed.), Marine Mammal Research: Conservation Beyond Crisis (pp.101-124). Baltimore: The John Hopkins University Press.
  3. Hildebrand, J. A. (2009). Anthropogenic and natural sources of ambient noise in the ocean. Marine Ecology Progress Series, 395, 5-20.
  4. Sound recordings courtesy of: Rain – Sonatech, Inc.; EarthquakesOcean Networks Canada; Hydrothermal VentsTim Crone; StormsHenry Bass, Roy Arnold and Anthony Atchley; Cracking IceOcean Networks Canada; Marine LifeSheila Patek; Surface Waves – Earth Vibes; Ship Passing Pod of OrcasOrcaLab; Commercial VesselsOrcaLab; Recreational VesselsOcean Networks Canada; Snowmobile on IceOcean Networks Canada; Pile Driving – Orca Sound; SonarOcean Networks Canada; Seismic Experiments – J & A Enterprises, Inc.
  5. Transport Canada. (2017). Understanding Anthropogenic Underwater Noise.
  6. Ross, D. (1976). Mechanics of underwater noise. Pasadena: Pergamon Press.
  7. The International Maritime Organization. (2013). Noise from commercial shipping and its adverse impacts on marine life.
  8. Veirs, S., Veirs, V., and Wood, J. D. (2016). Ship noise extends to frequencies used for echolocation by endangered killer whales. PeerJ. doi: 10.7717/peerj.1657
  9. Lesage, V., Barrette, C., Kingsley, M. C. S., and Sjare, B. (1999). The effect of vessel noise on the vocal behavior of belugas in the St. Lawrence river estuary, Canada. Marine Mammal Science, 15(1), 65-84.
  10. Discovery of Sound in the Sea. (2017). Beluga whale, white whale.
  11. Discovery of Sound in the Sea. (2017). North Atlantic Right Whale.
  12. Orca Network (2017). Southern Resident Orca Community Demographics, Composition of Pods, Births and Deaths since 1998.
  13. Port of Vancouver. (2017). ECHO Program.
  14. Fisheries and Oceans Canada. (2017). Evaluation of the Scientific Evidence to Inform the Probability of Effectiveness of Mitigation Measures in Reducing Shipping-Related Noise Levels Received by Southern Resident Killer Whales.
  15. Fisheries and Oceans Canada. (2017). North Atlantic Right Whale.
  16. Canadian Whale Institute. (2017). Changing Marine Policy to Protect Right Whales.
  17. Fisheries and Oceans Canada. (2017). Beluga Whale (St. Lawrence Estuary population).
  18. Species at Risk Public Registry. (2017). Species Profile.