Southern Shark Populations Appearing In Local Waters Could Be Sign Of Climate Change

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Researchers tagging a juvenile white shark.

With more than a few shark sightings on Suffolk County beaches this summer, it’s worth taking a deeper “dive” into understanding why shark populations are returning to Long Island and why sharks may be seen swimming close to shore during the warmer months.

Which is exactly what Chris Paparo and his team of shark researchers at the South Fork Natural History Museum and Nature Center’s Shark Research Team are doing — studying shark activity and shark populations on the East End by catching and tagging a variety of shark species.

Just last week there were shark sightings at Pike’s Beach in Westhampton Beach and Ponquogue Beach in Hampton Bays, after a large number of bunker were seen swimming in the area, and there have been several other sightings in local waters this summer.

“There’s a few different things that are going on here,” Mr. Paparo said. “Historically, shark populations were heavily overfished, and then through regulations and better management practices, many populations are starting to make a comeback like the sandbar shark, dusky shark and sand tiger shark.”

These sharks, Mr. Paparo said, have always lived in the area but were fished so heavily that their populations began to be decimated. After regulations on shark fishing, shark species have been reappearing over the last several years, he said.

New to the area are spinner sharks. “We saw them last year and have seen them a lot this year,” Mr. Paparo said. “But this is a species that generally does not range into New York, but is commonly found in South Jersey or Mid-Atlantic states.”

Due to climate change, as ocean temperatures are rising, Mr. Paparo and his team are noticing a shift in population of a lot of the southern species, and not only of sharks. Researchers have begun to see cobia, black drum and redfish, fish species that are generally found further south.

“As waters get warmer, their sweet spot is moving north,” he said, a subtle sign of the implications of climate change on our local waters.

Mr. Paparo also explained that the increased number of shark sightings is a direct result of more bunker, also referred to as the Atlantic menhaden, in the area.

“A lot of this also has to do with bunker,” he said. “It’s the most important fish in our ocean locally because everything eats them: Sharks eat them, whales eat them, dolphins eat them, eagles and ospreys eat them. Almost everything locally will at some point feed on a bunker.”

Bunker fisheries were unregulated for a long time. Mr. Paparo explained that people felt that since humans did not eat bunker it wasn’t an important fish, and they could take as many as they wanted from the ocean.

Bait fisheries would catch bunker to use them for bait for lobster and other fish, and reduction fisheries with giant factory boats would pull in tons of bunker and reduce them into other things like fish supplements, makeup, fish meal and aquaculture pellets, Mr. Paparo said.

“But a few years back, fishery biologists sat down and were like, ‘We have problems with blue fish, striped bass, tuna, sharks, whales and dolphins and the common denominator among all of those fish is that they all feed on bunker,’” he said. “So the question became, ‘Maybe we should start to regulate how much bunker is being taken out of the water?’ Eventually, they got New York State to say they won’t allow this in our water up to 3 miles or so.”

As soon as bunker regulation began several years ago, giant schools of bunker began to pop up along our shores, and as soon as the bunker showed up, the sharks, the whales and the fish began to reappear.

“This is not something crazy that’s happening,” Mr. Paparo said. “These animals have historically always been here, but because of the overhunting, the overfishing, they have vanished.”

He stressed that bunker returning to local waters and bringing the entire ocean ecosystem with them is indeed a good thing, and that sharks in the ocean are a sign of a healthy ocean ecosystem.

“You’re only going to have top predators like sharks when there’s a healthy ecosystem below them,” he said. “One of the big goals of our research at the SOFO shark research program is to better educate people about the sharks that are here, and help them understand how they contribute to our ocean ecosystem.”

Mr. Paparo also emphasized that though there may be more shark sightings, it shouldn’t be a cause for concern as all of the shark species in local waters are fish eaters and are not looking to snack on human beings.

“Everyone’s always afraid of sharks, but these sharks eat fish,” he said. “If you see a school of bunker, it’s probably not wise to enter the water. Not that the shark is going to come after you, but the bunker schools are so dense that if a shark is swimming around biting little fish, and you are in the wrong spot at the wrong time, you could potentially get bit.”

To escape the predators, the bunker will often swim close to shore, which is why sharks might be seen swimming close to the shore, Mr. Paparo explained.

“But the shoreline acts as sort of a wall, which helps the predators because it pushes the bunker up against the wall and then the sharks are able to feed. Thus, staying out of the water when you see these huge bunker schools would be a wise thing to do.”

This year, Mr. Paparo and his team have seen an incredible number of shark species, including the sandbar shark, the dusky shark, the sand tiger, the thresher shark, mako shark, blue shark, great white sharks, hammerheads, and spinner sharks.

“All of those sharks have the potential to get into the 300 to 400 pounds range, some of them can get up to 1,200 pounds, but all of the sharks that I’ve mentioned are fish eaters.”

He described this year’s shark tagging season as a “strange” one, as the research team has been striking out on the juvenile white sharks that they usually see plenty of. But the team has had a few firsts this summer season, like tagging a thresher shark with a CATS cam to record acceleration, speed, and video, tagging a spinner shark with a CATS cam, and tagging a spinner shark with a PSAT satellite tag.

“We’ve had some really groundbreaking stuff this season,” he said. “With the spinner sharks coming in, we’ve switched gears a little bit because nobody has really done much with them, and it’s a new thing for our area, so we want to get a better idea of how these sharks are utilizing our local waters.”

They’ve also turned a focus to searching for cownose rays, another fish that is typically found in South Jersey but has started to appear more in local waters due to climate change.

“We’re trying to focus on these fish as well because there’s a lot of concern that they’re going to dissipate our scallop population,” he said.

If there’s one thing to take away, it’s that these sharks aren’t out to eat you, Mr. Paparo said. He joked at the irony that people tend to “freak out” when they even hear the word shark, yet the same person will get behind the wheel of a car and start texting.

“They’re going to get in a car accident before they even see a shark at a beach,” he said. “If people had the same fear of driving as they do of sharks, maybe we’d all be a little safer on the road.”

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