Reduced shipping speeds benefit air quality and endangered whales
VENTURA — Research results show that the 10th annual season of the Protecting Blue Whales and Blue Skies (BWBS) Program in 2024 reduced the risk of deadly ship strikes to whales by 50%, underwater noise by 38%, smog-forming pollution by 1,400 tons and greenhouse gases by nearly 50,000 metric tons along the California coast.
Each year, BWBS recognizes many of the world’s largest shipping companies that opt in to whale-safer speeds of 10 knots or less to help reduce fatal strike risk to whales as well as air and underwater noise pollution.
After the 2024 Vessel Speed Reduction (VSR) Season from May to December ended, BWBS analyzed vessel Automatic Identification System data to determine enrolled fleets’ cooperation levels. Below are some summaries of the impact:
Ship Strike Risk: Research partners with Point Blue Conservation Science compared in-season transit speeds of participating transits to out-of-season speeds and quantified the reduction in fatal strike risk associated with that change. The analyses show that transits of participating vessels posed a 50.1% lower strike mortality risk to whales.
Underwater Noise: Research partners from Scripps Institution of Oceanography analyzed acoustic data and found that, across all program zones, the source levels of participating vessels were reduced by 38%, or 4.1 decibels, when the 2024 program was active versus inactive. Whales have evolved over the millennia to use sound for their daily life functions — to navigate, communicate and keep in contact during long migrations. Noise pollution disrupts these essential behaviors, threatening their ability to thrive.
Air Quality & Greenhouse Gas Emissions: Researchers compared in-season transit speeds of participating lines to historic, out-of-season speeds and quantified the reduction in emissions associated with that change. Analyses show estimated reductions of 1,405 tons of oxides of nitrogen (NOx), which is the equivalent of taking 900,000 cars off the road for a year. It also resulted in estimated reductions of 33 tons of oxides of sulfur (SOx), 8.4 tons of diesel particulate matter and 49,945 metric tons of regional greenhouse gases. When ships reduce speeds to the whale-safer threshold, it decreases air pollution and emissions by about 27% from baseline. NOx, a key contributor to ozone, is of particular concern, especially for communities overburdened by ports, hightraffic and industrial infrastructure. Ocean-going vessels emit a large portion of NOx affecting coastal California.
The environmental benefits driven by growing industry participation show that this program is making an impact.
“It’s been amazing to witness the growth of this program over the last 10 years and the range of impressive environmental benefits achieved. From seven shipping lines reducing speed in 2014 to 49 shipping lines opting in for 2024, this program serves as a shining example of what can be accomplished when government agencies, industry, and conservationists work together,” said Jess Morten with the California Marine Sanctuary Foundation.
Complete results and methodologies are available on the BWBS website