STEVE INSKEEP, HOST:
It is hard to see the bright side of a shark bite.
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UNIDENTIFIED REPORTER #1: Recent shark attacks - there have been at least three incidents...
UNIDENTIFIED REPORTER #2: Two recent shark attacks.
UNIDENTIFIED REPORTER #3: A fisherman and his son nearly running into a 12-foot great white shark off the coast...
INSKEEP: But to ocean researchers, shark sightings and even bites show a comeback.
RACHEL MARTIN, HOST:
Here's why sharks are returning to the waters off Long Island, N.Y. Chris Paparo of the South Fork Natural History Museum says when the sharks turn up, you know the ocean has plenty of food.
CHRIS PAPARO: Sharks need a healthy environment. So if the waters around us are not healthy, it can't support sharks. So seeing these sharks is really a sign that we're doing some really good stuff.
MARTIN: He traces the resurgence of sharks to the return of the smaller fish.
INSKEEP: They're called bunker or baitfish. Humans overfished them for a time. Their populations dropped, and sharks, dolphins and whales all suffered.
PAPARO: One common denominator is they all eat bunker. And the idea came up, like, hey, let's protect bunker. Or let's at least regulate bunker. Let's make it so it's not a free-for-all.
INSKEEP: Now there's more bunker, so you got more sharks. Now, just to reassure those on beach vacations, you're not going to need a bigger boat. The revival of sharks in some places does not make it very likely that you'll have to reenact scenes from "Jaws."
MARTIN: There were only 73 unprovoked shark attacks in the world last year.
PAPARO: It's rare. But nobody wants to be that statistic. Nobody wants to be number 74, you know, on the list.
MARTIN: So watch what the lifeguards tell you about sharks. And if you're warned that they are near, at least you know it's not all bad news.
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RUBEN BLADES: (Singing in Spanish). Transcript provided by NPR, Copyright NPR.