Last week a 533-pound Great White shark made its way into the Long Island Sound. The shark swam around the sound for three days and then went back out to sea without incident.

Researchers say shark sightings off the East Coast have been increasing over the past few years.

“On this coast, they were really decimated for a while. They’re really just now starting to come back,” says Rutgers associate research professor Thomas Grothues. “It’s not like we have a long history of study on them."

Grothues says that the seal population is also increasing and this may account for the increase in shark sightings.

“They’re going to be following those populations,” he says.

With thousands of beachgoers expected at the Jersey Shore this summer – are shark attacking something to worry about?

“It can happen. It does happen,” Grothues says. “We saw it historically but even much more recently in Massachusetts. In fact one of those was blamed on a tagged shark that was being followed.”

Experts say that if you are swimming and a shark is spotted, do not panic. Leave the water calmly and be aware of your surroundings while swimming.

Anyone who wishes to track one of the many tagged sharks swimming in local waters can do so on the Ocearch website.