Following an unusual shark sighting Monday off Duxbury Beach, officials increased their presence on both land and sea Tuesday — and warned beachgoers to be cautious and stay in shallow water.
“We are advising that if beach patrons wish to swim, they may do so at their own risk with the understanding that if they choose to enter the water, they should do so cautiously and avoid going into the water beyond waist depth,” the Duxbury harbormaster’s office said in a statement.
A State Police helicopter spotted a 15-foot great white shark approximately 150 yards off Duxbury Beach at about 2 p.m. Monday. The beach was closed for about two hours, while two harbormaster boats tried to force the shark out of the area.
Harbormaster Don Beers said Tuesday that officials are urging people to enjoy the beach, but to be vigilant when entering the water. He said the department had stepped up its patrols on water and on land.
“We just want people to be confident that everything is fine,” Beers said. “It’s not unusual for us to put a boat out there. We get shark reports all the time, but usually it’s just a false alarm. . . . This time was extremely rare because this time it was actually confirmed that it was a great white.”
Duxbury Fire Chief Kevin Nord said the shark spotted Monday eventually swam away to the south. He said there had been no sightings on Tuesday.
Greg Skomal, a biologist with the state Division of Marine Fisheries, said great white shark sightings off the coast of Massachusetts are not a new phenomenon, but spotting a shark so close to a Duxbury beach is somewhat unusual.
However, Skomal noted, sharks may be swimming around the area more than we think. “Sharks have been swimming around Massachusetts for hundreds and thousands of years. . . . We’re probably just spotting them more in recent years because of our increased patrols and technology,” Skomal said. He said there had been a couple of dozen great white shark sightings off the coast of Massachusetts this summer.
Most great white shark sightings in recent years have been off Cape Cod. Chatham, at the outer elbow of the Cape, has seen a number of sightings.
Skomal said he was not exactly clear what attracted the shark to the waters off Duxbury Monday, but one factor could be the increased presence of gray seals. Despite the sharks’ presence, however, Skomal said, beachgoers should not feel threatened.
“If the sharks were there to consume people, we would have had a lot more attacks in the area,” Skomal said. “As long as people are using common sense when swimming in the ocean, statistically, their probability of getting attacked is extremely low.”
Related coverage:firstname.lastname@example.org. Follow her on Twitter @TrishaThadani.