A Great White Shark Mysteriously Washed Ashore in Cape Cod, and Researchers Don’t Know Why

On Tuesday, the Orleans Police Department in Massachusetts received an unusual piece of news: A great white shark had mysteriously washed ashore in Cape Cod. Officials called local tow company Nauset Recovery Inc, to haul the 12.5-foot and 1,240-pound apex predator in the back of a truck through the beachside town of Orleans to the local transfer station for a necropsy.

“You really never know what kind of call you’ll respond to on any given shift,” writes the Orleans Police Department in a post on Facebook. “At least Sgt Elliott only needed to follow the tow truck and didn’t have to wrestle an unruly great white.”

Experts identified the shark as a mature adult male named “Koala,” who had been known to researchers since 2022.

But as for Koala’s cause of death, scientists are coming up empty-handed. Often, sharks are killed for their fins in an illegal practice known as finning. But all of this shark’s fins were intact upon pickup, as Dennis Reed, operator of Nauset Recovery Inc., tells Heather McCarron of the Cape Cod Times.

A Wednesday necropsy, led by Massachusetts Division of Marine Fisheries scientist Greg Skomal, found no signs of the shark being hooked, either, and uncovered no definitive signs of trauma. As such, its results were inconclusive, the Atlantic White Shark Conservancy says in a Facebook post.

Skomal tells the Cape Cod Times that a potential cause of death for Koala may have been an infection or beaching. Changes in the tides and sandbars can confuse a shark in shallow waters, where, Skomal says, it can beach itself if it “zigs when it should have zagged.” Researchers plan to continue in-depth analysis to determine how the shark died.

Commenters on the Atlantic White Shark Conservancy’s post were saddened over Koala’s death, with some hopeful commenters saying research on the animal will contribute to knowledge about sharks around the cape.

Policies protecting marine wildlife have increased Cape Cod’s great white shark population, which is now one of the densest seasonal concentrations of white sharks in the world, as National Geographic’s Alexandra Owens reported last year.

Peak season for the sharks runs from May to October. A recent four-year study—which included Skomal, the scientist who conducted Koala’s necropsy—estimated that nearly 800 individual white sharks visited their sampling area in Cape Cod from 2015 to 2018. The Atlantic White Shark Conservancy and various local groups even offer “shark safaris”—privately chartered boat expeditions where tourists have a chance to view Cape Cod’s great whites for a fee.

But the sharks, which historically swam around Cape Cod, were once much rarer in the area. Skomal told Jim Behnke of Scientific American last year that despite studying sharks off New England since the 1980s, he didn’t see one near Cape Cod until 2004.

The rebounding gray seal population in Cape Cod has been a key part of the resurgence of white sharks. Gray seals historically lived in Cape Cod for nearly 4,000 years, but their population was decimated by New England commercial fishermen who viewed the seals as competition for fish, according to the Natural Resources Defense Council. From 1888 to 1962, Massachusetts and Maine issued bounties on gray seals to promote hunting them, with a 2009 study suggesting nearly 72,284 to 135,498 were killed.

Under the 1972 Marine Mammal Protection Act, however, these seals earned federal protections. Along with the support of conservationists, the new legal safeguards allowed gray seal numbers to rebound in the 1990s. In turn, the white sharks bounced back.

“We believe that the appearance of white sharks over the last 15 to 20 years is in direct response to the number of seals along the shoreline,” Skomal told National Geographic. “It amounts to a new restaurant—or maybe a favorite restaurant reopening.”

Olatunji Osho-Williams | READ MORE

Olatunji Osho-Williams is an intern with Smithsonian magazine.