It seems that Maryland and Virginia weren't enough of a draw for a certain great white shark named Mary Lee. The shark—whose travels have gone viral on the Internet—left those waters and was pinged off the southern tip of New Jersey at 8:15 a.m. Thursday.
Scientists first tagged Mary Lee off Cape Cod, Massachusetts, in September 2012. The 16-foot-long (4.9-meter) animal was one of five great white sharks fitted with a satellite tag by researchers to track the predators' movements. All five sharks got names, and Mary Lee was named for the mother of one of the researchers.
One of Mary Lee's compatriots—Lydia—made history last year when she was the first great white observed to have crossed the Atlantic Ocean. It's likely that other great whites are swimming across the Atlantic too, Greg Skomal, a senior fisheries scientist at Massachusetts Marine Fisheries, said at the time. Lydia just happened to be the first that people were able to track. (Learn more about Lydia's transatlantic adventure.)
Mary Lee is no slouch either. "Lydia is broader scale in terms of movement north and east," Skomal said, "but Mary Lee's been all over the map as well." The predator has traveled a total of 19,474 miles (31,340 kilometers) since she was tagged more than two and a half years ago.
The shark's satellite tag is bolted to her dorsal fin and should last about four or five years. It's a real-time tracking device that sends location data to satellites every time the tag breaks the ocean's surface. The satellites send the data to researchers who can then track the animals.
Mary Lee has surfaced at least five times today while just south of Cape May, New Jersey. Her track from May 3 to May 5 is a jumble of zigzags just offshore of the Virginia-Maryland border. It's anyone's guess where she'll pop up next.
It's not unusual to see great white sharks close to shore, said George Burgess, director of the Florida program for shark research at the Florida Museum of Natural History. In fact, great whites "spend more of their time near shore because that's where they do most of their feeding," he explained.
Seals and sea lions are the preferred food for adult great whites, Burgess said, and those mammals need to haul themselves onto shore periodically to rest and warm up. So that's where the sharks go looking for them.
The shark biologist can't say for sure what Mary Lee was doing when she was nosing around Maryland and Virginia. But Burgess added that great whites on the U.S. East Coast do show some seasonality to their movements.
"The sharks are snowbirds, and they come down to northeast Florida in the wintertime," he said. "We think the timing is probably tied to the arrival of right whales off of Florida," as the whales gather in this area to give birth.
"No doubt the white [sharks] are following those groups looking for the old and the young and the stragglers, and will take advantage of any that don't make it," Burgess said.
Marine mammals of all ages may need to keep an eye out for more of these top predators. Recent research has shown that great whites are on the rebound off both the east and west coasts of the United States, thanks to federal and state protections put into place in the 1990s. (Learn more about why great white sharks are thriving in U.S. waters.)
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