Shark attacks: Is it safe to go back in the water?

Rate of great white shark attacks drops dramatically over the last half-century.

By Hanae Armitage 

Yesterday, the Jeffreys Bay surf tournament in South Africa came to a grinding halt after two sharks, suspected to be great whites, shook surfer Mick Fanning clear off his board. Broadcasters panicked, swore, and watched the chaos unfold, trying to comprehend and explain what was happening on live television. After a swift punch to one of the sharks—yes, he punched a shark—Fanning escaped on a rescue Jet Ski, bite-free. The attack is understandably receiving a ton of attention. But the commotion may also be racking up fear that is more fiction than fact, according to a new study, which finds that—at least off the coast of California—your chances of being bitten by a shark are the lowest they’ve been in decades.

“It’s important for the public to really understand shark attacks in terms of risk,” says Sal Jorgensen, a great white shark researcher at the Monterey Bay Aquarium in California. “What’s important is looking at the probability of being attacked, and that’s decreased dramatically.”

Jorgensen and his colleagues pulled together more than 6 decades of data, from 1950 to 2013, on injury-causing shark attacks from a database that has carefully followed and recorded attacks along the California coast. During this period, there were 86 attacks, and an increase from 0.9 to 1.5 attacks per year. However, the number of beachgoers in that same time frame exploded from 53 million in the 1950s to 165 million in 2013—a 211% increase. Doing the math, your chances of being bitten by a shark in California waters has actually decreased 91% over the past 63 years, the team will report later this month inFrontiers in Ecology and the Environment.

“If you put more people in the water, you have more people that could possibly interact with a shark,” says Francesco Ferretti, lead author of the study and a marine ecologist at Stanford University’s Hopkins Marine Station in Pacific Grove, California. “Take the lottery—the more people that buy tickets for the lottery, the more that there is a chance that someone will win. Or in this case, lose.”

But why are shark attacks themselves up? One possibility is that their numbers are on the rebound after years of shark hunting, thanks to the work of conservationists, but at this point, there aren’t enough data to confirm whether populations are indeed rising. Another possibility is that the recovery of seal and sea lion populations off the coast of California, thanks again to successful marine protection policies, are giving the sharks more reason to stay in these waters.

Still, researchers both on and off the study stress the importance of sharing shark information, like the whereabouts and abundance of sharks during specific months, with the public. They encourage beachgoers to base their decisions on the data to decrease dangerous shark-human encounters. For example, the study’s results showed that surfers are about 1500 times safer surfing between San Diego and Los Angeles in March, compared with surfing in Mendocino County in October and November.

“I think the thing that’s most important here is the need for education,” says Chris Lowe, an unaffiliated shark expert at California State University, Long Beach. “Studies like this show the big numbers and show what probabilities are true—we’ve been trying to communicate that for a while, and we just have to keep at it.”