Ocearch, an organization that helps scientists collect oceanographic data, detected the male shark, named "Cabot," off the coast of Connecticut Monday.
The shark, named after the Italian navigator John Cabot, who explored North America in 1497, had not been detected by the organization since it was tagged in Nova Scotia, one of eastern Canada's Maritime provinces on the Atlantic, in 2018. Cabot first traveled south to the Gulf of Mexico in January, before heading back up along the US East Coast.
"So cool to be tracking @WhiteSharkCabot in the Long Island Sound since as far as we know, it is unusual for white sharks to visit the area," Ocearch tweeted Monday.
A 2018 report by environmental group Save the Sound revealed that the Long Island Sound, which used to be very polluted back in the 1980s, is becoming cleaner due to federal and state investment in sewage treatment facilities in Connecticut and New York.
"Water quality in the Sound is now a far cry from conditions in the 1980s, when a steady increase in population and poorly treated sewage led to harbors full of dying fish and shellfish, dirty beaches, and waters almost devoid of oxygen," the organization said last year.
Chris Fischer, founder of Ocearch, recently told ABC News that spotting a shark in the Long Island Sound indicates there is abundant sea life in the area. He also cautioned swimmers to "demonstrate common sense" before going for a swim.
"I think it's a really great sign for the Sound, because these white sharks only go where there's an abundant amount of life, where the water is in pretty good shape… That's a real positive sign for the Sound there."
Dave Sigworth, a spokesperson for the Maritime Aquarium in Norwalk, Connecticut, also commented on the improvement in the Long Island Sound's waters.
"The Sound is cleaner, healthier than it's been in so many years," Sigworth told the New York Daily News. "So are we going to start to see occasional large apex animals, like humpback whales? Does that mean we are going to see more large sharks from time to time as there are more opportunities? These are questions that we have to be aware of."
White sharks can move between 100 and 150 miles a day. Cabot was last tracked Tuesday in the New York Bight, south of Long Island.
Ocearch did not immediately respond to Sputnik's request for comment.