Around New England

Great White Sharks Off Cape Cod A Success Story, Researchers Say

July 1, 2019

Scientific researchers are celebrating the surging populations of gray seals and the great white sharks who try to eat them off Cape Cod, even as beachgoers are worried about becoming the next shark-attack victim.

Five shark attacks have occurred since 2012, including a man in Truro who was seriously injured August 15, 2018 and a man in Wellfleet who was killed on September 15, 2018.

But researchers interviewed by the Cape Cod Times see sharks as a boon, not a bane.

“The recovery of the Atlantic white shark population is a conservation success not only for white sharks themselves but also for the overall health of our coastal ecosystems,” said Tobey Curtis, a shark expert and fishery policy analyst with the National Oceanic and Atmospheric Administration in Gloucester, according to the Cape Cod Times.

“We need these species. They’ve been gone too long and their restoration should be celebrated,” said Joseph Roman, a conservation biologist and an associate professor and fellow at the Gund Institute at the University of Vermont, according to the Cape Cod Times.

Tens of thousands of gray seals now come to Cape Cod every summer, followed by hundreds of great white sharks.

Researchers theorize that the prevalence of apex predators like the great white shark help keep numbers down and alter the behavior of second-from-the-top predators who can damage the populations of prey farther down the food chain if they don’t encounter top predators. They further theorize that effects are felt all throughout the ecosystem, down to the amount of seagrass growing on the bottom of the ocean – though they acknowledge that hard data is hard to come by.

The researchers quoted in the story are against culling seals through hunting by human beings, arguing that increasing numbers of great white sharks is a better way to deal with high seal populations.

That led the reporter to ask whether gray seal and great white shark populations may continue to grow indefinitely, along with the number of shark attacks on human beings off Cape Cod beaches.

“I can see where that uncertainty makes people uncomfortable. The numbers are not going to rise forever. But where those numbers will settle, it’s hard to know,” Roman said, according to the Cape Cod Times.