Reducing Underwater Noise

Many marine animals rely on sound for essential life functions such as communication, navigation, and foraging. Commercial shipping is a significant contributor to anthropogenic ocean noise pollution. Implementing VSR programs in regions with high whale presence is a crucial step in mitigating the harmful effects of chronic noise pollution.

See The Impact

Photo: Gabriel Dizzi

On this page

The Facts

How It Works

Measuring Progress

Verifification Partners

A whale's tail is visible above the ocean as a large cargo ship passes by in the background.

Photo: Dustin Harris

Underwater Noise and Marine Animals

Whales have evolved over the millennia to use sound for their daily life functions. Noise pollution disrupts these essential behaviors, threatening their ability to thrive.

The low-frequency noise produced by large vessels masks the communication signals of whales, dolphins, and other marine species, disrupting social interactions, mating calls, and mother-calf bonding.

Reducing noise pollution generated by ships has become a conservation priority for the United Nations’ International Maritime Organization.

Vessel speed reduction (VSR) is one operational noise reduction management action, as ships traveling at reduced speeds are emit less noise.

Reducing Underwater Noise one Ship at a Time

Participating shipping companies in the Protecting Blue Whales and Blue Skies program voluntarily reduce their speeds to 10 knots in VSR zones, reducing underwater noise as well as the risk of ship strikes to endangered whales, greenhouse gas emissions, and air pollution.

A large cargo ship carrying containers sails on the ocean with mountains and clouds in the background.

Photo: Ralph Clevenger Wildlife

Shipping lines participated and reduced their speeds to 10 knots or less for 85% of their total distance in VSR zones.

Underwater radiated noise pressure of participating vessels was reduced by 4.1 decibels compared to baseline.

Underwater radiated noise pressure of participating vessels was reduced by approximately 38%.

How We Measure Progress

Noise reductions associated with the program are determined by comparing underwater radiated noise of participating vessels during the VSR season versus time periods outside the VSR season. The program partners with the Scripps Machine Listening Lab and Dr. Vanessa ZoBell, at the Scripps Institute of Oceanography for underwater noise analysis.

2024 Methods & Results Report

How do you record underwater noise?

Scripps Institution of Oceanography analyzes ambient noise
levels at three sites within the VSR zones, with High-frequency Acoustic Recording Packages (HARPs) in the SB Channel and Monterey Bay shipping lanes, and with an autonomous underwater hydrophone (AUH) in the SF Bay shipping lanes.

Analysis of underwater radiated vessel noise metrics (source level and noise level) at three sites, the Santa Barbara Channel, Monterey Bay, and San Francisco.

How long has underwater noise been monitored?

Where can I find more research about this topic?

Where can I read more stories about this topic?

Verification Partners

The program works with third-party researchers and consultants to calculate the environmental benefits of participation.

Take Action

Help Blue Whales and Blue Skies spread awareness of responsible shipping practices, increase shipping company cooperation rates, encourage engagement with brands, and support further research and solutions for cleaner air, safer whales, and a quieter ocean.

Enroll your Fleet

Any company who operates container, car carrier, bulk cargo, or tanker vessels that pass through the Vessel Speed Reduction (VSR) Zones is eligible.

Click Here to Enroll

Photo: Ralph Clevenger Wildlife

A large MSC container ship sails across calm blue water under a hazy sky near distant mountains.

Become An Ambassador

Any company that ships goods with, or works with one or more participating shipping line is eligible to join.

Learn More

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Get Involved

Supply chain practices matter for biodiversity and air quality. Support responsible shipping practices for cleaner coastal air, safer whales, and a quieter ocean.

Ways To Get Involved

Photo: Robert Schwemmer