Vessel speed restrictions essential to protect endangered North Atlantic right whales and other large whale species, new study finds

BOSTON, MASS. (Jan. 24, 2024) – New research led by the New England Aquarium is illustrating the benefits of vessel speed restrictions when it comes to protecting large whales, including endangered North Atlantic right whales, from vessel strikes.

The study, published in the journal Biological Conservation, assessed potential vessel strike risk reductions for several species of large whales on the U.S. East Coast, including North Atlantic right, humpback, fin, and sei whales. These species have been injured or killed by vessel strikes throughout their range along the East Coast, including most recently a right whale calf observed earlier this month with severe propeller injuries to its head. In the study, researchers developed a metric for estimating risk reductions and found that expanding the area covered by a 10-knot speed limit reduces the risk of vessel strikes for these species.

“Our research shows the importance of a 10-knot speed restriction, rather than a 12- or 14-knot speed restriction. It also supports studies that have found the current speed restriction areas are too small. Our study shows that we don’t need to slow vessels down in all U.S. waters, but we need to implement restrictions in larger areas that cover important whale habitats,” said the study’s lead author Dr. Jessica Redfern, associate vice president of ocean conservation science in the Anderson Cabot Center for Ocean Life at the New England Aquarium.

Vessel strikes of large whales remain a conservation challenge throughout the world. To aid in defining effective solutions, the researchers developed a metric for estimating the reduction in risk achieved by management strategies that is easy to use and understand. The metric estimates risk reduction using the relationship between vessel speed and the probability that a strike is deadly, the distance a vessel travels, and whale habitat use.

Along the U.S. East Coast, Seasonal and Dynamic Management Areas were implemented by the National Oceanic and Atmospheric Administration (NOAA) in 2008 to protect North Atlantic right whales, an endangered species with approximately 360 individuals remaining, including an estimate of fewer than 70 reproductively active females. Seasonal Management Areas were established where the risk of a vessel striking a right whale is expected to be higher. However, there have been at least 14 lethal vessel strikes of right whales since 2008 in U.S. waters. Even one human-caused mortality puts the species at risk of extinction, showing that further action is required to support the recovery of the species by reducing vessel strike risk.

NOAA is currently considering modifications to the existing vessel speed rule to better protect North Atlantic right whales. Proposed changes to the federal vessel speed rule include expanding the size and increasing the time period for areas with seasonal speed restrictions, extending restrictions to include most vessels measuring 35 to 65 feet in length, and implementing mandatory speed restrictions in dynamic speed zones, which are established when and where whales are observed and likely to persist.

“This new research shows that the proposed expansion of the speed restriction areas will increase protections for right whales and supports the proposed revision to the vessel speed rule. It also shows that other large whale species would benefit from expanding these areas,” Dr. Redfern said.

Over the past three decades, scientists at the New England Aquarium have done extensive research to determine the frequency and location of right whale vessel strikes, identify the type and size of the vessels involved, and assess the impacts vessel strike injuries have on the health of individuals and the species.

“Vessel strikes are difficult to detect, and research shows that we detect a fraction of the strikes that occur. As a result of dedicated efforts by a broad community of researchers to document vessel strike injury and mortality, we have determined that vessels of all sizes can pose a risk to right whales and other large whales,” said Amy Knowlton, a coauthor of the new paper and a senior scientist in the Aquarium’s Anderson Cabot Center.

The North Atlantic right whale’s population continues to decline at an unsustainable rate due to human impacts, and the species has been experiencing an ongoing “Unusual Mortality Event” since 2017. Research shows that stressors, including fishing gear entanglements, vessel strikes, and climate change, are impacting individual survival and females’ ability to produce calves. Vessel strikes are one of the leading causes of the endangered North Atlantic right whale’s decline, and scientific evidence shows that slowing down vessels is essential to reducing deaths and serious injuries.

MEDIA CONTACT: Pam Bechtold Snyder, psnyder@neaq.org; 617-686-5068