We’re gonna need a bigger coast.

This summer has seen a tidal wave of shark sightings in local waters, including footage last week of a school of toothy predators devouring a wounded dolphin just yards from a Jersey beach and a young boy reeling in a 200-pound monster swirling in the shallows.

The shark surge is not just because of more people with cellphones on the sand, experts say.

“There are definitely more sharks in the area,” Paul Sieswerda, former curator of the New York Aquarium in Coney Island, told The Post. A perfect storm of successful shark conservation efforts, less-polluted waters, and warmer ocean temperatures from climate change has made our shores more welcoming to bait fish like menhaden — and the sharks who love them.

“It’s kind of like the menhaden are the wildebeests of the African plains — everything likes eating them and there are more every year,” Sieswerda said.

He said the huge schools of menhaden, a k a bunker, also attract seals, which is a favorite of great white sharks.

Local waters are also attracting species like blue, dusky, mako, sandbar and sand tiger sharks, which all range from 6 to 11 feet long.

“Warm temperatures are coming earlier in the year to the cooler waters off the coast and are lasting longer into the fall,” said George Burgess, director of the International Shark Attack File at the University of Florida.

“Sharks are now capable of moving farther north up the coastline and in greater abundance,” he explained. “With that, you have the inevitable increase of potential conflict between humans and sharks.”

Social media is filled with such close encounters recently.

On Aug. 2, two South Jersey teens reeled in a 6-foot shark while fishing on Ventnor City beach. A few days earlier, a video showed anglers in Long Beach Island also reeling in a large shark.

More footage from Beach Haven in late July shows 13-year-old Gianni Mandile landing a 200-pound shark from the beach. The boy and his dad, Joe, are seen dragging the massive fish to shore and exposing its rows of razor-sharp teeth.

There have been 21 attacks so far this year in the US, but none off New York or New Jersey.