Cape Cod shark alert rise is deceptive — but be careful anyway

Despite those sightings, Skomal said there has been less shark activity than usual on the Cape this summer. The numbers reported on the Sharktivity app, he said, are a result of its growing popularity with the public.

Members of the conservancy, who have been surveying sharks off Cape Cod from June to October for four years, have also started reporting their findings on the app more often, said Skomal, an expert on sharks who is part of the conservancy’s research team.

“It’s getting used more and more, so sometimes that gives people the perspective there’s more sharks,” he said.

Skomal said the conservancy’s research vessel takes to the waters off the Cape twice a week — on Mondays and Thursdays — to track and tag sharks, and most of the reports on the app come directly from them, with the help of Cape Cod beachgoers.

On Monday, eight sharks were reported on the app, and nine were reported Thursday.

Two sharks were reported Wednesday, most likely by someone outside the conservancy, Skomal said. No activity was reported Tuesday. The Cape Cod Times reported that two great white sharks were spotted Friday morning feeding on a whale carcass off the coast of Provincetown.

In June, there were few sharks swimming around Cape Cod, Skomal said, because it took the water longer to warm up this summer. Once the seas warmed in July, researchers saw a jump in the number of sharks, and then the sightings started to ramp up, continuing into August.

Skomal said that’s typical, as August is the peak month for shark activity on the Cape.

Sharks have been particularly fond of Orleans and Nauset Beach this summer and last summer, but Skomal recommended extreme caution anywhere in the ocean. Chatham has also long been a favorite hangout for the fierce predators.

“People who intend to swim off the Cape and in these areas where sharks are spotted should use common sense,” Skomal said.

Swimmers should listen to lifeguards, swim in groups, and stay close to shore, he said. They should also familiarize themselves with wind and water conditions of the day, as riptides pose more of a threat than sharks do.

“They have killed more people than sharks have, particularly in this state,” Skomal said.

Sharktivity alerts are available on Twitter @sharktivity, on the Internet map, and on Apple and Android smartphone apps.

Alyssa Meyers can be reached at alyssa.meyers@globe.com. Follow her on Twitter @ameyers_.