PORTLAND, Maine – A report that scientists are calling one of the most comprehensive studies of great white sharks finds their numbers are surging in the ocean off the Eastern United States and Canada after decades of decline – bad news if you’re a seal, but something experts say shouldn’t instill fear in beachgoers this summer.
The study by National Oceanic and Atmospheric Administration scientists, published this month in the journal PLOS ONE, says the population of the notoriously elusive fish has climbed since about 2000 in the western North Atlantic.
The scientists behind the study attribute the resurgence to conservation efforts, such as a federal 1997 act that prevented hunting of great whites, and greater availability of prey.
Great whites owe much of their fearsome reputation to the movie “Jaws,” which was released 39 years ago Friday. But confrontations are rare, with only 106 unprovoked white shark attacks – 13 of them fatal – in U.S. waters since 1916, according to data provided by the University of Florida.
They are, though, ecologically critical. They are apex predators – those at the top of the food chain – and help control the populations of other species. That would include the gray seal, whose growing colonies off Massachusetts have provided food.
A separate study published in PLOS ONE this month suggested that great whites – known just as white sharks – are also returning to abundance in the eastern north Pacific Ocean.
The elusive nature of white sharks and the lack of historical data about their population levels required the authors to rely on sightings of sharks, as opposed to other ways to count sea life, such as commercial fishing surveys and census counts, said Tobey H. Curtis, one of the authors of the Atlantic study.
White shark abundance in the western North Atlantic declined by an estimated 73 percent from the early 1960s to the 1980s, the report says. Shark abundance is now only 31 percent down from its historical high estimate in 1961, the report states.