South Atlantic right whales can have natural lifespans exceeding 100 years, but human-caused mortality has deeply driven down median life expectancy among their North Atlantic cousins to just an average 22 years, according to recent research.

North Atlantic right whales are highly endangered, with a population estimated at 372 animals in October 2024, according to the National Oceanic and Atmospheric Administration.

Along with the more common humpback and other whale species, right whales have been subjected to higher mortality in eastern U.S. waters in recent years. NOAA and whale research groups blame ship strikes and fishing gear entanglement, while opponents of offshore wind power projects try to correlate whale deaths with project surveys and construction.

The paper, “Extreme longevity may be the rule not the exception in balaenid whales,” was published Dec. 20 in the journal Science Advances. Lead author Greg Breed, a University of Alaska Fairbanks associate professor, noted the sharp north-south difference in lifespans between the closely related species is primarily due to human impacts.

“North Atlantic whales have unusually short lifespans compared to other whales, but this isn’t because of intrinsic differences in biology, and they should live much longer,” he said. “They’re frequently tangled in fishing gear or struck by ships, and they suffer from starvation, potentially linked to environmental changes we don’t fully understand.”

Historically, right whales were decimated by early American whalers and later by industrial whaling. The species slowly recovered after whaling was restricted by international treaties, but the North Atlantic species has suffered new losses off the U.S. East Coast.

North and south whale populations “have essentially identical life histories. Their currently believed maximum lifespans are both around 70-75 years,” the researchers reported. “Our results suggest that median life span of southern right whales is around 74 years, and a significant fraction live past 130 years, while North Atlantic right whales are currently living remarkably short lives, with median lifespans of only 22 years, and only a small fraction surviving past age 45.”

One U.S. environmental group, Public Employees for Environmental Responsibility, noted the paper is based on decades of data through 2020, and asserted “it also undercuts the idea that offshore wind power is an important driving factor on right whale mortality.”

Contributing Editor Kirk Moore was a reporter for the Asbury Park Press for over 30 years before joining WorkBoat in 2015. He wrote several award-winning stories on marine, environmental, coastal and military issues that helped drive federal and state government policy changes. He has also been an editor for WorkBoat’s sister publication, National Fisherman, for over 25 years. Moore was awarded the Online News Association 2011 Knight Award for Public Service for the “Barnegat Bay Under Stress,” 2010 series that led to the New Jersey state government’s restoration plan. He lives in West Creek, N.J.