Ships will have to reduce underwater noise – action plan

The International Maritime Organization (IMO) has announced the development of a final version of an action plan to significantly reduce underwater noise generated by ships. The idea behind the initiative is to minimize the negative impact of underwater decibels on the marine environment, especially wildlife and local communities. IMO is also planning the next steps to achieve undersea silence.

IMO’s new action plan

IMO’s subcommittee on the subject. The Ship Design and Construction Committee (SDC) met from January 22-26 this year. in London to finalize work on an ambitious action plan to reduce underwater noise in the seas and oceans. The plan will be presented to the Marine Conservation Committee in the second half of March as part of its 81. Session (MEPC 81) for approval.

The action plan designates IMO member countries, to which since 1960. includes Poland, a number of tasks that selected national institutions and offices will be responsible for implementing. These include. Establishing a 3-year experience-gathering phase. In it, organizations from each country will share best practices and lessons learned from the implementation of the revised guidelines adopted by the IMO in October 2023.

Efforts, seeking to reduce underwater noise, will also include:

• Raising public awareness, education and training for seafarers;
• Standardization of the underwater noise planning management process;
• Development of noise reduction goals and policies;
• Creation of technical groups in IMO structures obliged to exchange information;
• Development of tools for collecting and sharing information;
• Supporting research on biofouling, greenhouse gas emissions, and underwater noise and its effects on individual species and habitats.

GloNoise partnership

Efforts to reduce underwater noise are extensive and are not limited to the aforementioned action plan. Later this year, the GloNoise partnership project will be developed, involving the IMO, the United Nations Environment Programme and the United Nations Development Programme. Development (UNDP) and the Global Environment Facility (GEF). It aims to create a strong global partnership network with a special focus on developing countries that need support in awareness raising, data collection and institutional capacity building.

How does underwater noise affect the marine environment?

Ships are a major source of underwater noise. Depending on their type, size and mode of operation, they emit sounds with a freq from 10 Hz to over 1kHz and a strength of 160-200 dB re 1 µPa at 1 m. It can be assumed that the larger the ship, the lower the frequency and higher the strength of the underwater noise it produces. And as the size of the global fleet continues to grow by about 4 percent a year, the pressure on the marine environment is increasing.

Meanwhile, the underwater world is governed by its own rules. Animals that live here, including mammals, use sounds to communicate, forage for food, navigate, reproduce and avoid predators. Anthropogenic underwater noise severely disrupts these biological functions, causing stress, adverse reactions and even death of organisms. The low-frequency sounds emitted from large commercial vessels threaten whales, sea lions, some seals and fish in particular. And they carry themselves over very long distances, disrupting their lives also in coastal habitats where many species raise their young.

Ocean noise reduces the chances of survival for animals that are already under serious threat from climate change, marine pollution, predatory fishing and accidental collisions with vessels.

The need for action

Given the scale and pace of development in the maritime sector, it is necessary to take steps to reduce underwater noise globally. This is to be served by new technologies for producing quieter propellers that could be installed on existing ships. In addition, mitigation measures also include keeping hulls and propellers clean, acoustically isolating engines and reducing cruising speeds. The latter is also the primary way to reduce greenhouse gas emissions from maritime transportation.

There is no doubt that reducing underwater noise requires coordinated international cooperation and top-down imposed standards that balance the desire for profit. IMO’s efforts support the implementation of the 14. Sustainable Development Goal, which is: “Protect the oceans, seas and marine resources and use them sustainably.”