GEOFF BENNETT: After a recent spate of shark encounters, New York state is ramping up efforts to monitor the apex predator off the coast of Long Island.

In Massachusetts,experts are raising awareness about the surging population of great white sharks off Cape Cod.

Science correspondent Miles O'Brien has the story.

MILES O'BRIEN: In early July, around 5:00 in the evening off the southern shore of Long Island, New York, 15-year-old Peter Banculli and his friend Joe went out for an evening surf session at Kismet Beach.

The pair were 35 feet from shore, when they noticed the water was extra murky.

PETER BANCULLI JR., Shark Attack Victim: We were bout to catch a wave in.

Then, all of a sudden, like, in a blink of an eye, the shark was just there on my foot, like really, really intense pressure on my foot.

MILES O'BRIEN: Who helped you out?

How did you get to safety?

PETER BANCULLI: My foot was pretty much down the shark's, like, throat, in its mouth.

It was really scary.

I'm trying to wiggle my foot out.

I'm calling my friend for help.

And then eventually got out, ran up to the beach, got a good samaritan, and then called the cops from there.

I thought my foot was gone.

My foot was just all numb.

And I didn't really want to look at it, because I just knew it was bad.

MILES O'BRIEN: Peter was one of at least four people bitten by a shark on July 3 and July 4 off the coast of Long Island.

Each occurred on Fire Island beaches, a 32-mile-long barrier island.

GEORGE GORMAN, Regional Director, Long Island State Parks: It is a concern.

MILES O'BRIEN: George Gorman is regional director for Long Island State Parks.

GEORGE GORMAN: Prior to five years ago, never would have thought you would see a shark.

Now, I started my career many, many years ago, and there would be a shark report every maybe two, three years.

But that was it.

MILES O'BRIEN: Due to a steady increase in shark activity, New York Governor Kathy Hochul increased surveillance across Long Island beaches, providing more watercrafts and drones to be on the lookout for sharks and funding to cover the cost of training.

GOV.

KATHY HOCHUL (D-NY): Giving the lessons of last summer and seeing the change in sharks' behavior, we knew early on before the season even started we had to take preemptive steps.

MILES O'BRIEN: As beachgoers flock to the white sand, sharks too are swimming off the coast of New York's most popular beaches.

At least one beach delayed opening on July 4 after drones spotted dozens of sand sharks off the coast.

With drones to make sharks easier to spot, lifeguards had more time to clear the water after a sighting.

Cary Epstein is a lifeguard supervisor at Jones Beach State Park in Nassau County.

CARY EPSTEIN, Lifeguard Supervisor, Jones Beach State Park: When you're up in an elevated lifeguard station or a lifeguard stand, you can see up, and you can see out, but you can't see straight down.

MILES O'BRIEN: While all this causes alarm, those who study sharks say they are likely making a mistake if they bite.

TOBEY CURTIS, National Oceanic and Atmospheric Administration: People are not on the menu.

A shark is not interested in interacting with people or biting people.

We mainly think that this is a result of the sharks' natural food, mainly baitfish, generally being closer to beaches, where there's a lot of people in the water.

It's a very unusual dynamic where the shark food is so close to shore, but it's not unusual at all that there are sharks in New York.

MILES O'BRIEN: Tobey Curtis is a fishery management specialist with the National Oceanic and Atmospheric Administration.

He says warming waters are leading sharks to expand their horizons.

TOBEY CURTIS: Most of the sharks up in New York are smaller individuals.

Also, what's happening in New York is that there's new species from down south that typically didn't range as far as New York, things like spinner sharks and blacktip sharks.

These are species that generally remained south of New York waters, but now, because of climate change, they're moving into the area.

And, likewise, some species are moving further north.

MILES O'BRIEN: As beachgoers in New York remain on alert, larger great whites are surging off the coast of Cape Cod, swimming in the shallows.

To raise awareness of the increased population there, Atlantic White Shark Conservancy developed a Sharktivity app, where users can record and log shark sightings and encounters.

But why has Cape Cod quickly become one of the largest hot spots for great whites in the world?

BRYAN LEGARE, Center for Coastal Studies: Globally, we're losing sharks, we're losing habitat, we're losing these critical creatures in the different ecosystems.

In the U.S. waters on the East Coast, we have got a little bit of a different story.

MILES O'BRIEN: Bryan Legare is a seascape ecologist for the Center for Coastal Studies.

He says there are more great whites in these shallow waters because there are more seals there, one of their favorite meals.

BRYAN LEGARE: Seals, we almost hunted them to extinction up until the 1960s.

And with protection in Massachusetts and then federally in -- with the Marine Mammal Protection Act, it's taken about 50 years to recover that population.

MILES O'BRIEN: Sharks are necessary to maintain healthy biodiversity in our oceans, and encounters overall are decreasing.

According to the Florida Museum of Natural History's International Shark File, in 2022, the U.S. saw 41 unprovoked shark attacks, one of which was fatal.

That's down from 47 attacks in 21.

But if you find yourself face to face with a shark: TOBEY CURTIS: Most of the time, sharks, they will bite a person, they will realize they have made a mistake.

This is not their normal food.

They let go and swim off.

But if that's not the case, it's best to fight back, hit the shark on the nose or the eyes.

Those are very sensitive areas.

MILES O'BRIEN: Peter Banculli's left him with a broken foot, fractured in three places, and a torn Achilles.

He hopes to get back on the board in weeks.

I'm curious what mom and dad think about this.

PETER BANCULLI SR., Father: There's waves today, but his foot is in a cast?

I would say, let's go, you know?

MILES O'BRIEN: Kelly, how about you?

Are you ready to let these two go hang 10?

KELLY BANCULLI, Mother So, I have a very large fear of the water to begin with.

So this has deepens my fear.

But as a mom, I feel that the best way to overcome his fear is to get back on that board and continue to surf.

We live on a beautiful island.

We should be able to share the water together.

MILES O'BRIEN: Something Peter can't wait to do again.

For the "PBS NewsHour," I'm Miles O'Brien.