The marine environment is not a quiet place. Underwater sound is generated by natural sources (e.g. rain, storms, breaking ice and waves, marine life, etc.) and human-made sources (e.g. commercial ships and recreational boats, pile diving, sonars, etc.).
Many species, such as marine mammals, use sound to communicate. They depend on sound to navigate, find prey, reproduce and socialize. Interfering with such an important communication channel can result in changed behavior, hearing loss, increased stress levels, displacement to quieter waters, injury, and in the worst case, death.
Marine transportation is one of the main sources of underwater noise. An increase of this type of noise is anticipated in the future because of intensified traffic related to economic growth. The range of sounds used by marine mammals coincides with those emitted by ships. Cohabitation between ships and marine mammals is an issue, particularly in habitats that overlap with major navigation routes, such as the St-Lawrence estuary.
Even though the impacts of ship noise on marine life is well documented, many uncertainties remain on the disturbance mechanisms, and on which mitigation measures to adopt. The great number of factors involved (type of noise, affected species, water depth and temperature, etc.) complicates the search for practical solutions.
The International Maritime Organization (IMO) published voluntary guidelines in 2014 focusing on the negative impacts of shipping on marine life. While these guidelines provide technical guidance on how to reduce underwater noise from commercial ship, they have no legal status.
In Canada there are currently no regulations tackling underwater noise from ships. However, as an IMO Member State, Canada is very committed to the issue and has been proactive in doing research during the last years.
In 2012 Fisheries and Oceans Canada launched an important ship noise mapping project in the Gulf of St-Lawrence, capturing noise from commercial ships during a year. Combining this noise data with traffic information in the St-Lawrence enabled the drafting of an atlas of underwater acoustics to which marine mammals are exposed at a given site and time.
In 2014 Transport Canada mandated Green Marine to conduct a study to better understand human-made underwater noise to identify areas of research and provide a list with recommendations and actions to implement and to address the issue in collaboration with the marine industry and other partners.
The marine industry has also been proactive in recent years to find solutions. Underwater noise is now part of the Green Marine program which urges participants to implement concrete actions to reduce the impacts of their activities on marine mammals. The new performance indicator is the result of a successful collaboration between scientists (acoustician, naval architect, researcher), the marine industry (ship owners, ports, terminal operators), and the government (Transport Canada, Fisheries and Oceans Canada).
Several ship owners have started to implement measures to reduce ship noise: navigate below the cavitation inception speed, avoid abrupt acceleration, maintain propeller to limit cavitation noise, rerouting to avoid sensitive areas, insulate or install quieter equipment when building new ships.
Several Canadian ports, such as the Vancouver-Fraser Port Authority (through its ECHO program), are currently conducting research to help develop mitigation measures that will one day quantifiably reduce the noise from marine operations and their impact on marine life.
In the St-Lawrence, several companies, such as Canada Steamship Lines and Groupe Desgagnés, collaborate with the Marine Mammals Observation Network (ROMM) to collect data on marine species while navigating in order to advance whale behavioral science. (Marine mammal data collection project for the maritime shipping industry – Desgagnés fleet activity report (2015 to date), in French only).
Currently in Canada, government agencies, universities, industry, Indigenous communities and NGOs are combing their efforts to understand underwater noise and its impacts on marine life.
The Canadian government has also promised to allocate 1.5 billion dollars to develop new protection measures and to enhance knowledge in the context of the Oceans Protection Plan revealed in November 2016.