The organization said the sharks were detected at the Block Island wind farm, the Southwest Ledge, the southeast corner of Block Island, and on the west side of the island.
The four white sharks ranged in size from a little more than 8 feet in length to the largest, a male, at over 13 feet.
“We know exactly what shark came through: size, sex, when they were tagged. So, it’s pretty interesting, because its giving us more of a complete picture of what’s going on in Rhode Island and around Block Island in particular,” said Jon Dodd, executive director of the ASI.
The sharks were tagged between 2015 and 2019 by Dr. Greg Skomal, from the Massachusetts Division of Marine Fisheries. One of the sharks, named Miss Carolina, was tagged off Hilton Head, South Carolina in 2017, the ASI said.
The institute said the sharks were detected using an acoustic array that picks up unique pings from tags on the sharks.
The array has been in place for two years, and the ASI called the recent discovery the most significant finding to date.
ASI recently increased the number of acoustic receivers from two in 2019 to seven this season.
While some of the receivers are miles off the shore, others are pretty close.
“The one at the southeast corner is really almost below the lighthouse out there. If you were at the lighthouse and looked out with binoculars you’d see it,” said Dodd.
So are the sharks sticking around Block Island and taking up summer residency?
Or are they passing through to the Cape to feast on seals?
“Right now we’re not showing anything on the receivers that tell us they’re staying around Block Island. So far it looks like they’re passing through,” Dodd told NBC 10.
The data includes movement for the month of June. ASI said seeing activity for the entire summer will give researchers a clearer picture of the sharks habits.
“I think people should rest easy, because there’s always this question of, ‘hey are there more white sharks?’ Am I in danger? These sharks, it’s very clear, they’ve been doing this for a long long time. We’re just developing technology that allows us to know that they’re there,” said Dodd.