Expert: Shark Seen in Rye Was Most Likely a Blue Shark

was most likely a blue shark, a spokesman for the New England Aquarium said this morning.

Tony LaCasse, media relations director at the Boston aquarium, said a positive identification can't be made since no image was taken. But he said by far the large shark most commonly seen off the NH Seacoast at this time of year is a blue shark.

"Blue sharks are a medium-sized large shark. They can go from juveniles up to 8 or 9 feet, most often within the 150 to 300 pound range," he said. "Generally they're exclusively fish eaters, following bait fish or bluefin stripers."

LaCasse said he's heard from striper fishermen that stripers are running well, which supports his belief that the shark spotted off Wallis Sands Beach is a blue shark.

"They're a summer seasonal visitor," he said. "That is the most likely scenario. Blue sharks are the most common large shark in this area."

Some reports said the shark was believed to be a sand shark, better known as a dogfish. But LaCasse said those sharks are usually in the 2 to 3 foot size range.

"If the observation that it was a 5 to 6 foot animal is accurate, it's not likely it was a dogfish," he said. "When you're talking about large sharks, blue sharks make up the vast percentage of the summertime visitors there. It still could be something else, but it's less likely."

LaCasse said there are two worlds when it comes to sharks in New England – north of the Cape and south of the Cape.

"North of the Cape we get much less incidents of sharks," he said. "Great whites can traverse that area, but it's not a primary habitat they're hanging out in."

If the shark was a blue shark, it wouldn't be the first time blue sharks have caused a stir in this area. In the mid-2000s, LaCasse said, Old Orchard Beach in Maine was closed for two or three days because of blue shark sightings.

Though neither the blue shark or the dogfish is known for biting humans, he said beach officials were right to clear the beach on Monday.

"Just like any large wildlife in proximity to humans, you should take the prudent approach," LaCasse said. In the mid-90s, he noted, a school of bluefish drove a school of herring into shallow water in the Seabrook-Hampton area, and several people wound up getting bitten.

"These sharks don't normally bite people, but you need to play it safe," he said. "You always have to be careful of any type of interaction."

Still, LaCasse said people shouldn't be too concerned about their safety following Monday's sighting. He said beachgoers are more likely to be injured hitting a deer with their car on the way to the beach than they are to be bitten by a shark.

"About every three years we have some beaches closed in New Hampshire or southern Maine due to shark sightings," he said. "We're just sort of in the cycle. Once the word gets out, people get excited."

Now that one sighting has been reported, he said there likely will be more.

"We definitely get more sightings once the first one comes in," he said. "People are looking."