NGO Clean Arctic Alliance explains the impact of underwater noise on marine life and calls for the International Maritime Organization to tackle the issue.
As a workshop exploring the relationship between energy efficiency and underwater radiated noise from shipping took place at the International Maritime Organization (IMO) in London, the Clean Arctic Alliance called for international action to support the transition to ships that are both more efficient and quieter as efforts to decarbonise the global shipping fleet are stepped-up.
According to the IMO, the Workshop on the Relationship between Energy Efficiency and Underwater Radiated Noise from Ships (18-19 September) sought to engage participants who work in the greenhouse gas (GHG) and underwater radiated noise (URN) technical, regulatory and policy spaces, to include wide participation from industry with practical experience implementing both GHG/emissions reductions programs as well as those who are interested in or involved in reducing URN.
How underwater noise impacts marine life
As Eelco Leemans, Technical Advisor to the Clean Arctic Alliance, explains, the most important source of continuous underwater noise in shipping is cavitation, or production of vacuum bubbles by propellers.
The noise emitted by ships overlaps with sound produced and used by marine mammals, making it hard for these animals to communicate, find food and even to navigate. Fish, invertebrates and a variety of other marine species are also negatively impacted by ship-generated noise.
The easiest short term measure is for ships to slow down to reduce the cavitation effect, which not only results in – quieter and more efficient ships and lower greenhouse gas emissions, it will also reduce the number of marine animals hit and killed by ships.
… advised Eelco Leemans
Work should start immediately on “win-win” solutions like slower speeds and the use of modern wind power. Wind propulsion and wind-assisted propulsion are also important for efforts aimed at increasing ship efficiency, reducing greenhouse gas emissions and reducing noise, including on both large and small vessels.
… said John Maggs, President of the Clean Shipping Coalition
Additionally, Sarah Bobbe, Arctic Program Manager of Ocean Conservancy advocated that as cleaner, greener ships are designed and built to meet targets on reducing climate emissions, underwater noise reduction targets should be simultaneously achieved.
This can be done immediately by specifying the amount of noise reduction needed, and providing appropriate information and regulatory drivers to support the transition to efficient and quieter ships.
… concluded Sarah Bobbe
To remind, the 80th session of the Marine Environment Protection Committee (MEPC), 3-7 July 2023, approved revised Guidelines for the reduction of underwater noise from commercial shipping to address adverse impacts on marine life. The updated guidelines:
- Include updated technical knowledge, including reference to international measurement standards, recommendations and classification society rules.
- Provide sample templates to assist shipowners with the development of an underwater radiated noise management plan.
- Provide an overview of approaches applicable to designers, shipbuilders and ship operators to reduce the underwater radiated noise of any given ship.
- They are intended to assist relevant stakeholders in establishing mechanisms and programmes through which noise reduction efforts can be realized.
