Reducing Underwater Noise from Ships

Kicking off IMO’s new plan to quiet down

Many marine animals, including whales and dolphins, depend on sound to navigate through the ocean, find prey, hide from predators and communicate with each other. For this reason, noise from ships and other sources such as seismic surveys can negatively impact marine animals by making it harder for them to hear. This can disrupt their feeding, resting and breeding behaviors and can lead to hearing loss, physical injury and chronic stress. Even invertebrates like octopuses can be victims of noise-induced damage. Their statocyst, a small organ responsible for their balance and spatial orientation, can be damaged by underwater noise, rendering them unable to find prey, evade predators and reproduce.

Given these potential negative impacts on ocean life, Ocean Conservancy has advocated for several years for the International Maritime Organization (IMO) to reduce underwater noise from ships.  In January 2022, the IMO’s Sub-Committee on Ship Design and Construction (SDC) began a new round of work to address the harmful impacts of underwater noise. While previous work completed in 2014 resulted in the creation of voluntary noise reduction guidelines, unfortunately, the non-mandatory nature of the guidelines led to few in the shipping sector actually prioritizing their uptake. This resulted in a continued increase in noise levels in the ocean, including sensitive regions like the Arctic, where underwater noise from ships has an even greater impact.

Thankfully, the subcommittee acknowledged that previous work to reduce underwater noise had not succeeded and approved a work plan to revise the 2014 guidelines and develop comprehensive next steps which will actually be effective in reducing underwater noise. The workplan included a commitment to engage the Inuit of the Arctic and other Indigenous communities and incorporate Indigenous knowledge in this process. To protect ocean animals from the harmful impacts of underwater noise, this new work must include mandatory measures to ensure industry-wide action.

But what measures can ships take to reduce underwater noise?

A combination of ship design, ship maintenance and policy solutions can decrease underwater noise and its harmful impacts. Advancements in new technologies, such as quieter propellers, have already been developed and can be installed on new and existing ships. Vessels can also maintain polished, clean hulls and propellers, insulate engines, or easiest of all, just slow down to reduce noise. Reducing speed is a particularly simple action that has the added benefit of decreasing fuel use and harmful emissions.

As SDC moves forward with its work, it’s critical that its next steps are ambitious in scope and reflect the urgency needed to address underwater noise from ships that continues to increase at alarming rates. The IMO and its member countries must set policy to require ships to quiet down. Join us in this critical and urgent work to secure mandatory measures that successfully reduce noise and protect the ocean wildlife species it impacts.


Browse Topics
Our work is focused on solving some of the greatest threats facing our ocean today. We bring people, science and policy together to champion innovative solutions and fight for a sustainable ocean.
Read more
View Current Posts
Back to Top Up Arrow