The Florida Panhandle has seen back-to-back shark attacks this month, with at least one swimmer in critical condition. The incidents have drawn attention to a broader trend documented by marine scientists: shark encounters along the East Coast are rising as shark populations rebound and warming ocean temperatures shift where sharks spend their time.
Despite the jarring headlines, the individual risk of being bitten remains tiny. Gavin Naylor, director of the University of Florida’s shark-research program, put the chance of a bite at less than one in four million.
Shark populations have recovered since the 1990s, buoyed by conservation efforts that protected both sharks and their prey. Some 130 species now patrol the East Coast, Naylor said. Most stay at depths where they are unlikely to encounter people, but some species are more likely to stray into waters used by swimmers and surfers, especially at coastal hot spots. More people in the water combined with more sharks, he said, means more encounters.
Warmer ocean temperatures and an increasing supply of prey have drawn more great white sharks to feed in the waters around Maine, according to Gregory Skomal, a fisheries biologist with the Massachusetts Division of Marine Fisheries.
Off Cape Cod, the trend is especially visible. “They spend as much as 50% of their time in water less than 15 feet deep,” Skomal said. “It wasn’t like that in the ’80s and ’90s.”
The range expansion is not limited to great whites. Jon Dodd, executive director of the Atlantic Shark Institute, said more shark species are appearing off Connecticut and Rhode Island. The dusky shark, a species that can be found in the Long Island Sound, has been recently documented eating seals near Nantucket, Dodd said.
Sharks that overwinter near Florida often migrate north in warmer months, and some of the most well-trafficked stopover zones are along the Outer Banks and Cape Hatteras. John Tyminski, a senior data scientist at OCEARCH, a nonprofit shark-tracking organization, said sharks frequently pause in those areas to feed and rest.
Florida remains the nation’s hot spot because of the sheer number of people and sharks in the water at the same time. New Smyrna Beach, a surf break near a fish-rich inlet, is a documented area where bites occur, Naylor said.
Dean Grubbs, a shark expert and research professor at Florida State University, said multiple human-shark interactions have recently been reported near the Florida Panhandle. He attributed part of the shift to warming sea surface temperatures, which are drawing more tropical species further into the northern Gulf of Mexico.
“You’re seeing more sharks and species in places compared with a couple of decades ago,” Grubbs said.
Young sharks tend to remain in shallower areas near shore, where larger predators are less common. As sharks age, they pursue a wider range of prey and expand their range. Naylor said he suspects that younger great whites are more likely to mistakenly bite humans as they begin to mature and focus on new prey like seals, which are common near beaches.
Swimmers can reduce their risk, Dodd said, by avoiding the water at dawn or dusk when sharks are most active, staying close to shore, and swimming in groups.
MSI previously reported on a related development off Nantucket: a fisherman caught and released a nine-foot great white shark in the waters there this month, the latest sign of the species’ presence in New England waters.