A recent spate of shark sightings and attacks along the East Coast, from Cape Cod and Long Island all the way to Florida, have prompted officials to close beaches and warn swimmers to stay in lifeguard-supervised areas.
But while these reports of shark activity are scary and can seem like they signal a big change in risk for beachgoers, they’re not out of the ordinary. Scientists who study sharks say shark attacks aren’t any more common globally than they were even a year ago.
Grid spoke with Gavin Naylor, program director at the Florida Program for Shark Research, about the recent attacks, what might be causing them, and why the public impression of sharks is wrong.
This conversation has been edited for length and clarity.
Grid: Is the amount of shark attacks that we’re seeing unusual?
Gavin Naylor: So it depends on the scale that you look at it. If you look at it globally, we were having a fairly quiet year up to about June, and then it’s picked up a little bit. But it’s basically a pretty standard year around the world. Now, looking at it from the perspective of somebody who lives on the south shore of Long Island, where there were no bites last year. There were two there before that and very few before that — all of a sudden there’s five in a row. So it looks like a very unusual year.
We look at trends globally over the large scale, so we don’t get too bothered by local phenomena because little things happen in different places every year. So one year it’s Hawaii. Next year, it’s off the coast of Madagascar. The next year is New Caledonia and then South Africa — then it’s Western Australia. We’ve got different little hot spots that seem to be where something really weird is going on, and everybody thinks that the world is going to crash and burn. But if you look at it over the entire planet, these are just local pulses, and they don’t really amount to a global change and patterns of bites.
G: There’s also been some speculation floating around that these incidents could be a sign that sharks’ ranges are changing, either because of climate change or other reasons. Is that something that could be happening, and is there data to back that up?
GN: That’s a great question. So there is no data, but it may be true. Sharks have been around for 400 million years, and one of the reasons that they’re able to survive so well is because when conditions get unfavorable, they move somewhere else. They’re large animals, and so they can do that. And so you know, modern sharks move all over the place all the time. Not all of them, but many of them. They’re pelagic animals and lots of the pelagic animals move across oceans.
If there’s more food in one part of the world, and there isn’t in another or there’s abundance — [like] off the coast of Long Island — then absolutely, they’ll move there. Why is that? It’s because these are predators. They follow food. So if the food is distributed differently, then they will definitely move.
Why is the food different? Well, could it be global warming? It could. Do we have the data? No, we don’t. So it could equally well be just a little eddy of the Gulf Stream and spins out, or it could be something to do with a hot air cell over Colorado that has knock-on effects on the jet stream, which then affects the winds and which has got absolutely nothing to do with global warming.
Everybody jumps on the global warming bandwagon. And as a scientist, I’m a little bit worried about that because I like to be able to say things that we can stand behind and have data, because if we’re wrong and the next time we do something, people will say, “Well, you got it wrong last time. What do you know?” There are a lot of scientists actually who are fairly glib with a global warming explanation, and you know, they may be right, but they don’t have the data to make that statement.
G: Is that because there are just so many things that impact sharks environment more generally?
GN: Yes. It’s a multivariate problem and a multiscale problem. And we’re not sure what scale processes are affecting the distribution of the bait fish, whether it’s a local thing in the Northwest Atlantic or if it’s a global phenomenon — we don’t have the models to be able to make those predictions. It’s hard enough for the weather guys to be able to tell us what the weather is going to be doing in a week. Well, it’s even harder with ocean currents. I’m not saying that they’re wrong, I’m just saying we don’t know that.
G: When people hear “shark,” many immediately think of “Jaws,” for example. Do sharks get a bit of a bad rap from movies like that? Do you think public perceptions around sharks are skewed in a negative manner?
GN: I like to tell people this and journalists don’t like to report it: Humans are pathetic in the water. If sharks wanted to eat them, it would be so easy for them. If they tasted good and a shark were like, “Oh, my goodness, there is a human, let me have a bite,” there would be between 10,000 and 50,000 bites a day. There’s a lot of sharks in the ocean and a lot of people that are recreating there.
We don’t see that. We see very few, about 70 a year. And although there are 70, more than half of them are in poor visibility water where the shark makes a mistake. So the fact that the bites that we do see are where conditions are turbid and where people happen to be intersecting with where there are sharks sort of underscores the notion that sharks do not eat people — we aren’t on the menu.
The other thing to know is that there are 540 different kinds of sharks, and everybody thinks they’re all exactly the same. A white shark is about as different from a black tip shark as a kangaroo is from a human. Yeah. We wouldn’t say, “Oh, we saw an increase in mammal bites this year,” as if they’re all exactly the same.
I mean, if a T. rex just came in your garden and walked around, you’d be terrified, but you’d also, hopefully, be incredibly excited. Because it’s this ancient animal that is spectacular and really interesting and intriguing. So are sharks! They do some goofy things that we still don’t understand. Some glow in the dark and take light and retransmit it on a different wavelength. They do a host of really bizarre and unusual things. They’re fascinating animals, and it’s quite dispiriting to me as somebody who studies them that the only thing people seem to be interested in is how scary they are. They’re a barrel full of widgets that are really interesting, and they do some spectacular things.
I think that if we just took a deep breath and just tried to learn about sharks, we would find them a lot more fascinating. These animals have been around for nearly half a billion years, and they’ve got some clever tricks.
An earlier version of this article misstated how many years sharks have existed. This version has been corrected.
Thanks to Alicia Benjamin for copy editing this article.