'Sharks are here now.' Whale, seal shark bites prompt warning off Massachusetts coast

As another summer season begins on the beaches of Cape Cod and other coastal areas, researchers are reminding people to be on the lookout for Atlantic white sharks after recently observing two marine mammals with fresh bite marks off Chatham and Plymouth — one just this week.

Researchers with the New England Aquarium on Thursday issued an advisory ahead of Memorial Day for people returning to the shore to be aware of their surroundings, report white shark sightings, and review shark safety.

John Chisholm, an adjunct scientist with the aquarium’s Anderson Cabot Center for Ocean Life, said he spotted two white sharks during an aerial survey on Wednesday off Nauset and Monomoy, one just a couple of hundred yards offshore and one about a mile out. On the same day, he also flew over a dead minke whale with fresh shark bites reported by Pythias Sportfishing.

"It shows that the sharks are here now," said Chisholm, who last month also observed a seal off Manomet Point in Plymouth with a fresh bite wound.

With beach weather returning, he said, "this is a good reminder for people to review shark safety guidelines and be shark smart."

How to be 'shark smart'

Being shark smart includes looking for seals — a favorite prey animal for white sharks — on the beach and in the water.

"Also look for big schools of fish," Chisholm said, as well as large groups of birds diving into the water that can indicate the presence of a lot of fish.

"A lot of people think the sharks only eat the seals," he said, but pointed out they will also go after fish, so "any signs of activity, especially in the zones where we know we get a lot of shark activity" should be noted.

It's also helpful to note any drop-offs or trenches where seals and sharks may hunt, and to stay close to shore.

"A lot of the east-facing beaches on Cape Cod drop off very quickly or will have a trench between the beach and a sandbar where there's deeper water," Chisholm said. "Sharks do get in there."

Although most white shark sightings have been off the Outer Cape from Provincetown to Monomoy, awareness should apply to any beach, he added, since "these sharks travel the whole coast of Massachusetts."

Just as people tend to check the weather and traffic reports before heading to the shore, he suggests also making it a habit to check the Atlantic White Shark ConservancySharktivity app "to see if there's any local shark action." The app, on which the aquarium collaborates, tracks shark sightings and pings from tagged white sharks picked up by the New England science community's network of offshore receivers from Massachusetts Bay to Nantucket and Vineyard sounds.

"A lot of people think of the ocean as their own personal recreation area, but you're going into the wilderness when you're going into the water," Chisholm said.

Evidence of sharks feeding on dead whale

While Chisholm's sighting of a seal with a fresh shark bite off Plymouth happened about a month ago, the dead minke whale was spotted on Tuesday by Capt. Damon Burden. of Pythias Sportfishing.

"It was about 10 miles east of Chatham," said Burden on Thursday.

He was hosting one of his fishing outfit's pelagic bird watching trips when they noticed a bunch of birds around a particular spot in the ocean, he said. When they went in to investigate, they didn't see any sharks, but did see bites taken out of the whale's carcass.

"There was still some blood trickling out" of one of the bites, Burden said, which made him believe the whale was recently deceased.

Chisholm said "the sharks were feeding off it," but "it definitely wasn't killed by the sharks."

Burden, who's seen plenty of white sharks on fishing outings, was surprised to see evidence of the sharks at this time of year. "I wouldn't think a great white would be out there that early," he said.

Is it early for white sharks to be showing up?

Gregory Skomal, a leading shark researcher with the state Division of Marine Fisheries who collaborates with the Chatham-based white shark conservancy, said scientists expect to see the sharks returning as the waters start warming up. The recent evidence of their presence is not a surprise to him.

"The timing is pretty typical," he said.

At this point, Skomal said, it's still early in the season. "The bulk of the sharks have yet to come," he said, noting that, depending on how warm June is, white shark activity could ramp up as soon as mid to late June and early July. The season usually peaks between August and October.

Cape Cod research about Atlantic white sharks

Over the last decade, Cape Cod has emerged as a world-renowned hotspot for Atlantic white sharks visiting during the summer and fall, and researchers have been taking advantage of the chance to study the sharks' behavior to understand what motivates them and to inform creation of public safety policies.

Skomal works closely with shark scientist Megan Winton and other researchers from the conservancy to tag sharks during the season and collect underwater video footage of white sharks around Cape Cod. They use multiple tools, including satellite, acoustic, accelerometer, and camera tags to track the sharks’ habitat use.

Last summer, 80 individual sharks were recorded in local waters over the course of five months — not counting any that evaded the scientists' underwater video cameras. More than 700 individual white sharks have been cataloged in the Northwest Atlantic in recent years. That's not to say there are hundreds of sharks present at any given time — the scientists emphasize there is a lot of coming and going during the season.

Skomal said plans for this season include continuing to tag as many new sharks as possible, and to deploy more tags with video capabilities to gain an understanding of how the sharks hunt. They will also continue using drones to sight sharks and study their behaviors.

Most of the standard acoustic receivers they use to detect previously tagged sharks have been put back into the ocean, he said, and the rest should be deployed by June. They're also preparing to return five live receivers to the waters off Outer Cape beaches — these devices pick up movements of tagged sharks in real time and transmit advisories to public safety personnel on shore.

Heather McCarron writes about climate change, environment, energy, science and the natural world. Reach her at hmccarron@capecodonline.com, or follow her on X @HMcCarron_CCT.

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This article originally appeared on Cape Cod Times: Great white sharks sighted off Cape Cod. Most return in June, July