Action Point 1
Developing new policy to drive the design and operation of quieter ships at the International Maritime Organization (IMO). Underwater noise from shipping is the leading contributor to ocean noise pollution worldwide. We must work together at the IMO to build on the current progress and craft policies that achieve our vision for the future of a global shipping fleet that is both carbon-free and quiet
Shipping is a global concern and the effects of a growing maritime transportation network on biodiversity must be addressed at that level through the United Nations’ International Maritime Organization (IMO)
In 2014, the IMO adopted its first voluntary Guidelines for the reduction of underwater radiated noise (URN) from commercial shipping, aimed at mitigating the impacts of vessel noise on marine life. A lack of technical detail and little to no uptake pushed the IMO to revise the Guidelines in 2023 to provide updated technical knowledge, encompassing ship design and retrofit approaches, as well as maintenance and operational approaches to noise reduction such as speed reductions. Guidance on URN management planning is also a key component of the Revised Guidelines, pushing industry to monitor, assess, and mitigate the noise impacts of their fleet. The IMO also launched an experience-building phase (EBP) through the fall of 2026 to gather lessons from real-world implementation of the Guidelines.
One key lesson from the earlier guidelines was that voluntary measures alone are unlikely to deliver broad and lasting reductions in underwater noise. In response, the IMO adopted a URN Action Plan to progress policy and technical work in parallel in the short, medium and longer term. Several actions in the Plan highlight the interest in advancing the Organization’s energy efficiency, decarbonization, biofouling, and underwater noise goals in tandem. As fleets turn over, the alignment of these priorities offers a powerful opportunity to address environmental challenges in a holistic and cost-saving manner; many actions that reduce noise can also cut fuel use and emissions, producing clear co-benefits for climate and biodiversity.
Building on this progress, IMO Member States now have a crucial opportunity to shape the next generation of IMO policies - transforming voluntary guidance into effective measures that move the global fleet toward the shared vision of a shipping industry that is both carbon-free and quiet.
Action Point 2
Establishing marine protected areas that take into account the protection and restoration of the natural ocean soundscape. We are committed to achieving the effective protection of at least 30% of the global ocean by 2030, and we invite and encourage all States, relevant international organizations, and multilateral bodies to take action to reduce human-generated ocean noise when designing and implementing marine protected areas and other effective area-based management measures
Underwater noise is often overlooked as a pollutant, and is rarely addressed in the designation and management of Marine Protected Areas (MPAs) and other effective area-based conservation measures (OECMs), yet it represents a critical stressor for many forms of marine wildlife, particularly marine mammals. Human-generated noise from vessels, construction, operation of industrial activities, seabed mapping and other activities can mask communication, disrupt feeding and breeding behavior, and displace species from key habitats.
Integrating underwater noise considerations into MPAs and OECMs involves identifying and minimizing noise sources that affect the acoustic environment of these sites. This can include prohibiting or restricting noise-producing activities that pose a high risk for marine wildlife, imposing seasonal limits when animals are most vulnerable, or adopting noise interference mitigations (e.g., bubble curtains), less impactful operation of sources (e.g., lower power/slower speeds, reduced duty cycles), use of alternative technologies (e.g., tuneable sources), or concentrating noise in areas with less impact (e.g., traffic lane shifts). Establishing acoustic buffer zones around protected areas to reduce the impacts of noise within the MPA and prioritizing the protection of naturally quiet habitats that serve as refuges for sound-sensitive species are also effective strategies.
Incorporating underwater noise management into conservation planning should begin early—during site identification and design—so that the acoustic environment is evaluated alongside other ecological and socio-economic criteria. Environmental impact assessments (EIAs) are a best-practice tool for managing such risks and are recommended under the Convention on Migratory Species (CMS) and required for Parties to the High Seas (BBNJ) Treaty when proposing potentially impactful activities in (or that could impact) areas beyond national jurisdiction.
Action Point 3
Investigating and implementing effective solutions to reduce vessel impacts on sensitive ocean wildlife. There are many potential measures to reduce harmful levels of noise in the ocean, and they can also bring wider environmental benefits. These measures can include vessel speed reduction, re-routing, technical or operational improvements, and may vary in effectiveness depending on circumstances.
Coastal and nearshore waters are known to sustain diverse and rich ecosystems, and are also where maritime activity is often most intense. Ships of all sizes, from large commercial carriers to smaller ferries, tugs, and recreational craft, generate significant underwater noise. In busy port areas, this noise can be a constant presence. Furthermore, coastal waters are key areas of overlap between vessels and marine wildlife, where the risk of collisions between vessels and whales, dolphins, or other large marine animals is heightened.
A growing suite of proven tools and management measures can reduce the impacts of shipping on marine ecosystems. Vessel speed reduction programs are among the most effective, simultaneously decreasing underwater noise, collision risk, and fuel consumption. Other measures include re-routing or shifting shipping lanes away from critical habitats, designating seasonal or dynamic management areas, and incentivizing the adoption of quieter ship designs and operational practices. When applied strategically, these approaches deliver multiple environmental co-benefits—cutting emissions, reducing underwater noise, and protecting vulnerable species.
Action Point 4
Supporting capacity-building to assess and reduce ocean noise by sharing available tools and knowledge, including those tools currently being developed by the IMO’s GloNoise Partnership.
Significant technical progress has been made to create tools and guidance to support the assessment and mitigation of underwater noise, but the capacity and resources to access
and use of such tools is not universal. Therefore, it is critical to support and engage in initiatives, such as the UNDP-GEF-IMO GloNoise Partnership, which assists developing countries to raise awareness, build capacity, define baselines and promote international policy dialogue on mitigation of underwater noise from shipping.
Not all sources of underwater noise have equal implications for wildlife. However, tools exist to quickly understand the key drivers of noise in places that matter to wildlife, and the best tools to use to reduce impacts. Countries can do a lot to advance innovations and operational approaches that make their waters quieter and are focused on places that are important for ecotourism and that support indigenous peoples and local subsistence economies. There is much to be gained through regional and global information sharing to accelerate and incentivize the implementation of quieter designs and operational methods tailored to places with common ocean noise problems.
Platforms and fora to host information supporting decisions to reduce underwater noise are maturing globally, supported by big-data initiatives. These resources allow practitioners around the world to compare research and mitigation trial results and consider alternatives for action that best match their protective objectives, driving efficiency in our collective work to quiet the ocean.
For more information about how to get involved, please contact us.