There have been more than 150 great white shark sightings since June off the coast of Cape Cod, Massachusetts, a popular East Coast vacation spot, according to scientists.

This week alone, more than 20 great white shark sightings logged off the Cape, prompting three days of beach closures in a row beginning Tuesday.

The Atlantic White Shark Conservancy's sharktivity app indicates that there have been more that 161 shark sightings off the coast of Massachusetts since June 1. The same shark can be spotted multiple times, scientists note.

Newcomb Hollow yesterday after swimmers were removed from the water due to a white shark spotted. August-October are peak months of white shark activity off Cape Cod. Whether or not a sighting is reported, we advise caution and recommend not venturing beyond waist deep water. pic.twitter.com/TaTOwt8vxf — Atlantic White Shark Conservancy (@A_WhiteShark) August 1, 2019

"We've seen more white sharks this past July, the last month, than we did last year at this time," said Gregory Skomal, a marine biologist with the Massachusetts Department of Fish and Game.

High water temperatures and a high population of seals, which sharks feed on, off the coast of Cape Cod are attracting them, Skomal said. The population of great whites is also rebounding after humans exploited the species for a long period.

But the increase in shark sightings doesn't necessarily indicate a higher number of sharks off the Cape.

"We have to realize that it's been a really hot summer, and more and more people are going to the beach, more and more people are carrying cellphones, and they have drones and they have all kinds of electronic toys that allow them to see the sharks," Skomal said. "And so some of these sightings are simply correlated with the fact that there are more people out there paying attention."

The Cape Cod shark frenzy comes amid the Discovery Channel's Shark Week, which drew almost 35 million total viewers last year.

The increased sightings have helped marine biologists by allowing them to tag and track a greater number of sharks. Skomal said the state Department of Fish and Game has been able to tag 15 sharks so far this year, a number not reached until closer to the end of summer last year.

But he also realizes that the spate of shark sightings could scare beachgoers, and he has some advice.

He said people worried about a shark attack should stay close to shore and steer clear of seals. "The sharks are not here to eat us; they're here to eat the seals. Sadly, they occasionally make a mistake, but it's really a low probability," Skomal said.

Last year, a man died after being attacked by a shark off the coast of Cape Cod. He was the first to die from a shark attack in Massachusetts since 1936.