Navigating the Noise: The Intersection of Canadian Ferry Routes and Critical Marine Habitats

Getting your Trinity Audio player ready...

Click to view glossary

Ferry Noise in Critical Marine Mammal Habitat

In the dark undersea world, sound is essential. Marine life relies on sound for communication, foraging, reproduction, and navigation. However, as human activity in the oceans increases, so does underwater radiated noise. Various industries contribute to ocean noise—offshore energy, construction, military operations, and of course vessel traffic. With growing activity from commercial shipping, offshore developments, fishing and recreational vessels, underwater noise from vessels is increasing.

This increase has consequences for marine life, particularly species that rely on sound to survive, such as marine mammals. Underwater noise can mask natural sounds, which may make it difficult for animals to communicate, find a mate or prey, or even avoid predators. Some may change their behaviours, such as communicating less or avoiding or abandoning habitat. Underwater noise may also increase stress or have other health impacts.

In response to these concerns, Transport Canada’s Quiet Vessel Initiative supports research to reduce underwater vessel noise. The Quiet Vessel Initiative provides federal funding for research and development projects to advance and test promising technologies, vessel designs, retrofits and operational practices to make vessels quieter and more efficient, contributing to the protection and recovery of the marine environment and endangered marine mammals.

This series of articles explores the results and shares the challenges identified by some of the Quiet Vessel Initiative-funded projects.

Impact of ferries in Canada’s coastal waters

With the world’s longest coastline at 243,000 kilometres and crisscrossed with navigable rivers and lakes, Canada relies on ferries as an essential part of its national transportation system. Coastal and inland ferries facilitate the movement of people and essential goods to and from remote communities and support tourism. Ferries are also significant contributors to the level of underwater noise in coastal waters.

Ferry routes can pass through critical habitat areas used by species at risk. In British Columbia, coastal ferry routes overlap with areas used by three populations of killer whales, among many other marine mammals. All populations – one transient and two residents – are deemed at risk, but the Southern Resident killer whales are listed as Endangered under Canada’s Species at Risk Act. Approximately 74 whales remain in the Southern Resident population¹, reduced from a population peak of 98 in the mid-1990s since tracking started in 1976.² All of these killer whale populations use sound to communicate, and the Northern and Southern Resident populations also rely on sound to hunt for fish.

Find out more about the Recovery Strategy for the Northern Resident and Southern Resident Killer Whales in Canada

In eastern Canada, the St Lawrence Estuary has a resident population of Endangered beluga whales, which are the southernmost population of this species, more typically found in Arctic waters. Called the “canaries of the sea”, belugas rely on sound to communicate. This population is estimated at approximately 1,850 individuals but has not recovered since hunting ended in 1979 and is less than 20% of what it was in the early 1900s.³ Moreover, since the mid-2000s, the proportion of young belugas has declined. Vessel activity in the St. Lawrence and Saguenay Rivers overlaps with critical calving and nursery habitat for belugas.

Find out more about the action plan to protect the belugas

During the summer and autumn months, the Gulf of St. Lawrence hosts around 40% of all known North Atlantic right whales, which migrate to the area to feed and socialize. Listed as Endangered in Canada, there are approximately 370 whales in this population.⁴ Underwater noise pollution, including from vessel activity, is one factor contributing to the decline of this species by limiting how far they can communicate in the ocean as well as causing ongoing stress. Entanglement in fishing gear and vessel strikes are the most common causes of North Atlantic right whale fatalities.

This article was prepared by Clear Seas on behalf of Transport Canada as part of the Quiet Vessel Initiative and is part of a four-article series on ferries and underwater vessel noise.

Continue learning about the new discoveries and challenges in making vessels quieter with the other topics in this series here

The Quiet Vessel Initiative is a federally funded program through Transport Canada. Industry partners and researchers interested in potential research and development collaborations to advance innovative solutions in marine technology are invited to contact the Quiet Vessel Initiative team at Marine-RDD-maritime@tc.gc.ca.

References

1. Center for Whale Research Photographic Population Census, July 1, 2025 ↩︎
2. Independent Science Panel on SRKW Recovery (2025). Strengthening recovery actions for Southern Resident killer whales. https://doi.org/10.70766/32.7300, pg. 13. ↩︎
3. https://www.dfo-mpo.gc.ca/species-especes/mammals-mammiferes/whales-baleines/beluga-eng.html ↩︎
4. https://www.dfo-mpo.gc.ca/species-especes/mammals-mammiferes/whales-baleines/narw-bnan/index-eng.html ↩︎