Local News

Video shows shark munching on seal off Nantucket, closing beach to swimming

While filming seals, a visitor suddenly saw blood and captured the moment along the island's eastern shoreline.

Great Point Lighthouse in the Coskata-Coatue wildlife refuge. (Richard Perry/The New York Times)

July 10, 2024

2 minutes to read

A visitor to Nantucket filmed a shark feeding off a seal at Great Point on Sunday, later identified by an expert as a dusky shark.

According to the Nantucket Current, Sandy Fink filmed the shark while traveling to the island from Orlando with her boyfriend, Ron Welter.

Welter was fishing along the shore, and Fink was videotaping seals when she suddenly saw blood.

“I was like, ‘Is that blood?’ Wait! That is a shark, and he is eating the seal,” Fink told the Current.

She ran to show Welter the video just in time, as he was about to enter the water for a dip.

Fink did not respond to a request for comment Wednesday.

The Trustees of Reservations told the Current that there were separate reports of sharks attacking seals along the island’s eastern shoreline on Sunday. The organization, which owns the Coskata-Coatue Wildlife Refuge, prohibited swimming all Sunday afternoon.

It isn’t the first time sharks have been spotted feeding off Great Point in recent years. In July of last year, swimming was closed after multiple sightings of predation on seals. In May of 2022, the first great white shark sighting of the season occurred off the shores of Great Point.

Shark expert Greg Skomal identified the animal spotted on Sunday as a dusky shark based on the width of its head, the placement of its dorsal fins, and its size and length.

Skomal told Boston.com it is unusual for a dusky shark to prey on a small seal. Typically, they munch on fish such as menhaden, mackerel, sand eels, bluefish and striped bass.

“We are paying attention to it,” said Skomal. “It’s not something we are shrugging off.”

According to NOAA, the dusky shark inhabits the inshore to outer continental shelf along the eastern coast from Cape Cod and Georges Bank to Florida, including the Gulf of Mexico and the Caribbean Sea.

Distinguishing characteristics include a gray or bluish-gray color with a white bottom and distinct dorsal fins.

“The dusky shark is not new in Massachusetts,” said Skomal. “But for most of the years I’ve been around, there have been clear signs on a population level that the dusky shark is in trouble.”

The International Union for Conservation of Nature, an inventory of global conservation status and extinction risk of biological species, lists the dusky shark as endangered.

The lack of dusky shark sightings is most likely due to the dramatic decline in the population over the last several decades due to slow biological productivity, overfishing for its meat and fins, and bycatch.

Dusky sharks have had some protection since 2000, and if one is caught, it must be released, Skomal said.

There are signs that the population is rebounding, with more sharks showing up at the northern extent of their range, Cape Cod.

“The U.S. is doing an effective job in rebuilding shark populations and probably has one of the most effective management measures on the planet for sharks,” said Skomal. “The dusky is one of those species.”