NGOs Welcome Guidance on IMO Plans for Reducing Underwater Noise

Published Jan 24, 2026 10:12 AM by The Maritime Executive

[By Clean Arctic Alliance]

As a meeting of the International Maritime Organization’s (IMO) Sub-Committee on Ship Design and Construction (SDC 12) closes today, the Clean Arctic Alliance welcomed the clear guidance on how the IMO must reduce underwater noise pollution and its impacts, and the recommendation of a two year extension of the three-year “experience building phase” (EBP). 
 
During SDC 12, Member States finalized a list of key technical aspects for reducing underwater noise from shipping, which will inform future policy considerations by the Marine Environment Protection Committee (MEPC) during the proposed two-year extension of the Experience Building Phase, and will be initially considered by MEPC 84 in April.
 
The Clean Arctic Alliance, made up of 24 not-for-profit organisations, is calling on member states to ensure the IMO continues to push for progress and action in reducing underwater noise from shipping, especially in Arctic waters where the levels of underwater noise are anticipated to nearly quadruple by 2030.
 
“During this week’s IMO meeting, member states agreed on clear guidance on how we must reduce underwater noise pollution and its impacts during the proposed extension of the experience building phase. At the two forthcoming MEPC meetings this year, we hope to pursue policy that will move beyond voluntary guidance”, said Sarah Bobbe, Senior Manager, Arctic Program at Ocean Conservancy, a member of both the Clean Arctic Alliance and the Clean Shipping Coalition. “So far, this work has not kept pace relative to the growing threats faced by regions experiencing increased shipping traffic, such as the Arctic, underscoring the need for parallel policy advancement through the IMO’s Marine Environmental Protection Committee in the coming months.”
 
For many marine organisms sound is the most important means of communication. Under water vision is restricted and without good hearing ability, elementary functions such as navigating, finding prey and partners can be hampered. This is of particular importance for marine mammals, and also for fish and even invertebrates.
 
“Much of the Arctic has been free of anthropogenic (human-sourced) sound for a long time, but with increased human activity, Arctic waters are becoming more noisy every year”, said Bobbe. “An important source of noise is shipping, specifically from propellers and engines. Since shipping has increased substantially during recent decades, underwater noise is a growing problem, contributing to serious impact on the Arctic ecosystem.”

 
Key IMO Papers:
 
A paper submitted to SDC 12 by WWF and presented during a lunchtime side event, SDC 12-INF.17 – Spatio-temporal information on Arctic whale migration routes for consideration in voyage planning and other measures to reduce the impacts of underwater radiated noise on marine life provides new maps that show, for the first time, the migratory corridors of Arctic whales across the Arctic Ocean. 

Marine mammal migratory corridors are specified in both the URN Guidelines and the Polar Code as areas of special concern because they contain high concentrations of animals sensitive to impacts of shipping. The maps provide mariners with new information on where they need to take measures in migratory months, which in the Arctic, are in spring and autumn. Operational measures, such as rerouting and restricting speed, can reduce impacts on migrating whales, and these measures go hand in hand with technical measures to quieten ships through new builds and modifications. WWF invites mariners to use the maps in voyage planning, and urges member states and the IMO to implement location-specific rules and recommendations to reduce impacts of underwater noise in migratory corridors.

“By putting migratory corridors on the map for these three whale species that we know to be especially sensitive to underwater noise, we hope to support the shipping community to take necessary measures to safeguard them”, said Melanie Lancaster, Senior Specialist, Arctic species conservation for WWF’s Global Arctic Programme and member of the Clean Arctic Alliance. “From the maps, we see that whales migrate impressive distances between their summer and winter habitats, some swimming thousands of kilometres across national borders and even into the high seas of the Central Arctic Ocean. It will take international cooperation among states, ship operators, shipping companies and IMO to ensure their safe and quiet passage.”

The WWF paper outlines how IMO Member States should consider adopting shipping measures in the Arctic that build on the practice within IMO to safeguard whales from the adverse impacts of shipping. 

Mandatory ship reporting systems and recommendatory seasonal areas to be avoided have been adopted for North Atlantic right whales along the United States east coast and recommendatory speed restrictions have been adopted as an Associated Protective Measure (APM) for whales in the North-Western Mediterranean Sea Particularly Sensitive Sea Area (PSSA). The paper provides the necessary information for similar preventative measures to be adopted to safeguard whales in the Arctic.

A paper submitted to SDC 12 by the Clean Shipping Coalition - SDC 12/8/3 and sent onto MEPC 84 for consideration, shares the findings of a study on the potential underwater radiated noise (URN) impacts of LNG development on marine mammals in the Gulf of California. The paper examines the potential effects of URN from LNG tanker traffic on migratory and resident whales, as well as related impacts on air quality and greenhouse gas (GHG) emissions.

The proposed LNG terminals and the resulting increase in LNG tanker traffic are expected to pose serious threats to the Gulf of California's unique biodiversity and conservation areas, including those designated as a UNESCO "World Heritage Site" and "Important Marine Mammal Areas". These developments increase the risks of air, water, and underwater noise pollution. Given the Gulf of California's critical ecological role—particularly as a habitat for resident and migratory marine megafauna—a precautionary approach to industrial development is essential. It is increasingly evident that the region's ecological integrity is incompatible with the scale and nature of heavy marine traffic associated with proposed LNG facilities. 

Many regions, such as in the Arctic and the Gulf of California in Mexico, share similar potential impacts from underwater noise, and both have seen low shipping traffic in the past. Shipping traffic has been increasing in the last decade in the Arctic, while in the Gulf of California the developing LNG infrastructure will bring unprecedented vessel traffic to a marine area with enormous ecological value, in particular for marine mammals. 

“Our recommendations to SDC 12, and to the forthcoming discussions at MEPC 84, for the Gulf of California are equally important for the Arctic as both regions could see devastating impacts from future increased shipping, especially from LNG tankers, for marine wildlife particularly sensitive to noise, like marine mammals”, said Andrew Dumbrille, Co-Founder and Director of Equal Routes - a member of both the Clean Arctic Alliance and the Clean Shipping Coalition. “The recommendations include: acknowledging the irreversible impacts of underwater noise caused by LNG tanker traffic on marine mammals' behaviours and habitat; promoting the development of ship design that takes into account the serious damage underwater noise causes to the marine habitat; and opposing LNG traffic in critical ecological marine areas because of, among others, the underwater noise pollution it causes, affecting marine mammals and other marine species. Both the Gulf of California and the Arctic are marine areas of incredible ecological, social and biodiversity importance for the planet, the impacts of increased noise would change the quality of the marine habitats irrevocably.”
 
Relevant IMO Paper Submissions

• SDC 12/8*: Experience-Building Phase for the Reduction of Underwater Radiated Noise From Shipping – Report of the Correspondence Group
• SDC 12/8/3: Potential Underwater Noise from Shipping Impacts of LNG Development on Marine Mammals in the Gulf of California
• SDC 12/8/6: Experience-Building Phase for the Reduction of Underwater Radiated Noise From Shipping – Comments on document SDC 12/8
•  SDC 12-INF.17 – Spatio-temporal information on Arctic whale migration routes for consideration in voyage planning and other measures to reduce the impacts of underwater radiated noise on marine life 

 
About Underwater Noise:
For many marine organisms sound is the most important means of communication. Under water, vision is restricted and without good hearing ability, elementary functions such as navigating, finding prey and partners can be hampered. This is of particular importance for marine mammals, and also for fish and even invertebrates.
 
The Arctic has been almost free of anthropogenic (human-sourced) sound for a long time, but with increased human activity, the Arctic Ocean is becoming more noisy every year. An important source of continuous noise is shipping, specifically from propellers and engines. Since shipping has increased substantially during recent decades, underwater noise is a growing problem, contributing to serious impact on the Arctic ecosystem. 
 
According to a study by Transport Canada, the World Maritime University and WWF, the existing guidelines have not been effective in reducing underwater noise, namely because of their voluntary, non-regulatory nature. Research from the Arctic Council has shown that Arctic underwater noise has significantly increased in recent years. Ship traffic is also increasing in the Arctic, and given the unique special Arctic environment, underwater noise from ships has a much higher impact than in other parts of the global ocean.
 
The most important source of continuous underwater noise in shipping is cavitation, or production of vacuum bubbles by propellers. The noise produced by this process leads to masking, where the frequency of ship noise overlaps with sound produced and used by marine mammals.

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