More than a dozen sharks, including great whites, have been tagged by trackers swimming off the northeast coast.
The Daily Mail spoke with trackers who said the sharks would likely remain in the region until early fall.
One of the sharks is a massive 528-pound female white shark swimming off the coast of Cape Cod. At least 14 were found in the waters off Long Island.
Shark attacks are extremely rare, but officials caution that swimmers should be aware of where shark populations have been spotted to take precautions against potentially violent encounters with the creatures.
On Sunday, a lifeguard was bit on his chest during a training exercise near Smith Point Beach. He was stitched up and is recovering well. He said he had to fight the shark off of him.
"I felt sharp, sharp pain and once I felt the rubbery texture, I knew it was some kind of shark," Zachary Gallo told CBS. "I hit the shark three times. I went boom, boom, boom. I guess in the third one it spun back and it's tail hit me in the chest."
The northeast coast regularly seeks shark numbers spike during the early-to-mid summer. Sharks generally spend the spring in the south until the start of summer, when they swim north looking for warmer waters.
Unfortunately that is also a peak time for swimmers who also want to enjoy the more temperate Atlantic waters. Cape Cod officials warned swimmers to be wary while they recreate over the summer.
Trackers have tagged more than 280 great white sharks off the coast of Cape Cod since 2009, allowing them to learn more about the sharks' behaviours and migration patterns.
In addition to the warmer waters, the sharks are also migrating for food. They tend to cluster around the Atlantic Ocean side of the cape where they can hunt the large seal population.
Greg Skomal, a state marine biologist who spoke with The Daily Mail, advised swimmers to be especially cautious when swimming in areas where the shoreline drops quickly into deep waters, as those areas are more likely to contain sharks.
The sharks further south, near Long Island, are much smaller than the great whites further north. There are more than 20 species of sharks that can be found in the waters around Massachusetts.
Sharks do not generally target humans, and researchers believe many attacks occur when the animal confuses a human floating near the surface of a body of water for a seal or other typical food source.
