Jaws is a summertime classic. It’s been terrifying moviegoers for more than 50 years. And many a beachgoer has at least a lingering memory of that unmistakable, two-note John Williams theme in their mind as they wade into the brine.
The Eastern seaboard waters that serve as the setting of the film have indeed seen an uptick in great white sightings over the past few decades, with ocean temperatures rising and gray and harbor seal populations booming. But last summer, researchers at the Atlantic White Shark Conservancy published an account of the first ever direct observations of another large, marine predator killing and consuming seals. Megan Winton, a senior scientist at the Atlantic White Shark Conservancy, and colleagues published dramatic 2023 drone footage of a dusky shark chasing and eating a gray seal in shallow waters off the northern tip of Nantucket in the Environmental Biology of Fishes.
Recently, Winton told Mass Live that dusky shark populations declined by as much as 80 percent in the latter half of the 20th century. The shark—which can grow to about 12 feet long—was listed as endangered on the IUCN Red List of Threatened Species in 2019. She and her coauthors also published reports from the public of dusky shark predation in Northeastern waters from 2023, and she says that observers including scientists had initially assumed that the sharks were great whites, which aren’t even in the same family as duskies. “Everybody by and large assumed they were white sharks, including us, because that was the species that had made a comeback,” Winton told Mass Live in an article published last week. “It’s great that in areas where management plans and protections have been provided, we’re able to see a comeback.”
Read more: “Lessons for the Return of Great White Sharks”
Previously, scientists had thought that dusky sharks fed more on fish, so observations of seal predation elucidated the species’ diet and a key cause for the downward trend in its populations: seal overhunting. “Nobody knew they were capable of actively hunting for and preying on seals,” Winton said. “This was a really incredible discovery.” She added that she and her colleagues expected to see more great whites and duskies this summer.
The return of dusky sharks as well as great whites—and their seal prey—to waters off of the Northeast United States is a positive sign for two species whose populations had been trending downward thanks to human activity. Hollywood depictions of sharks preying on humans aside, it’s nice to see marine ecosystems bouncing back after decades of overuse. 
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Lead image: Steve Garner / Adobe Stock
