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We Asked an Expert Why Shark Attacks Are on the Rise

Mick Fanning's shark attack is the latest of dozens this year. What the hell is going on?

by Max Rann
Jul 21 2015, 2:40pm

Image via Flickr user Lwp Kommunikáció

A great white shark surfaces in New Zealand. Image via Flickr

The dramatic close shave between Australian surf star Mick Fanning and what was probably a great white shark, live on TV, is just the latest event in what's been a terrible year for shark attacks. Australia has been victim to 13 recorded attacks already this year, while in the US, beachgoers in North Carolina have been subjected to eight since the start of June. This record-breaking spike has been attributed to a " perfect storm" of conditions conducive to shark attacks.

But it seems no one is 100 percent certain what these conditions are. Why are so many sharks killing people? There's talk of overfishing and global warming, and the notion that sharks are attracted to increased shoreline activity. But in order to push past hype, and tell shark head from shark tail, we decided to put some of the most widely touted theories to Dr. Mark Meekan, a shark expert at the Australian Government's Institute of Marine Science.

VICE: Hi, Mark. First up, the overfishing argument. People claim that fishing is reducing available food and sharks have been forced to try other foods that include humans. Does this stack up?
Dr. Mark Meekan: I don't give this argument too much credit. From a science point of view, there are a lot of links in the chain for that to be true, and we've got no evidence for them. The shark's prey would have to be overfished, and there would have to not be an alternative prey for them to switch over to in order for them to turn to humans. You need some good hard data to support that argument.

That's one of the big problems with white sharks, and sharks in general—there's very little hard data about populations and how they've been changing over time. Yet people like to spout these sorts of theories and the arguments tend to be very, very emotive. And without any real data, they're given airtime.

A bull shark. Image via Flickr

What about the " fishing beside beaches" argument? This purports that fishing from piers close to beaches is attracting sharks, as they can smell blood and come to beaches to attack people?
You certainly raise your risk of shark attacks in an area where you have blood and dying fish in the water. If you go spear fishing, for example, you're presenting sharks with signals of distressed and dying fish in the area. And you have to be more aware of the risks of that activity than you do if you're just wading in knee-deep water. They're two different activities that give you two different risk profiles. But does that explain the high rate of shark attacks? I don't think so.

Do you accept the " global warming" argument, which claims rising sea temperatures are causing sharks to inhabit areas they hadn't previously and are now attacking people in these areas?
Well, first we need to understand where these animals are, how many we've got, and where they're moving. These are all key research projects that we're currently involved in.

We know that there are just three species that are attacking humans, and they're bull sharks, tiger sharks, and white sharks, of course. And these sharks all move huge distances. We have tiger sharks moving up and down the coast of West Australia, going as far as Indonesia and South Australia. This is mirrored by white sharks that inhabit cold waters in Tasmania and South Australia in the summer months but then, during the winter, head north to West Australia. Similarly, there've been white sharks tagged off California that spend winters out in what they call "The White Shark Café" off of Hawaii. And bull sharks tagged in the Great Barrier Reef have been seen in Sydney Harbour. These animals are moving very large distances across waters off different temperatures.

But the problem is that we have such poor data on the distribution and abundance of most shark species that we couldn't tell whether this is being changed by global warming. The data we have is just so poor at the moment that we don't know how many sharks we've got.

A great white in Baja, California. Image via Flickr

OK, it seems to me that we don't know a lot. Is it even true that we're seeing more shark attacks than we used to?
The real problem with rates of shark attacks is that you're trying to take statistical trends on very rare events. Shark attacks, although they make the news, are extremely rare events. And the problem with trying to create statistics about rare events is that they rapidly become meaningless.

We can't tell if shark attacks are increasing or simply more people are getting in the water. The only thing we can conclude is that an increasing population puts more people in the water, so you're likely to have an increase in shark-human encounters.

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