PhotoIt might have been enough that this year marked the the 40th anniversary of the movie “Jaws”, but then there was a rash of shark attacks along North Carolina's Outer Banks.

All of a sudden long-dormant fear of an ocean predator was top of mind among the public. It wasn't just “Shark Week” on a popular cable TV channel – it was shark summer.

All of this makes conservationists uncomfortable and worried that the U.S. is about to declare war on sharks. That would be a mistake, they say.

Coexisting with predators

"We don't necessarily have to see conservation and public safety as at odds with each other,” said Fiorenza Micheli, a Stanford researcher and co-author of a new study tracing the history of shark attacks in California. “This is also true of coastal economies. People can coexist with predators."

Micheli and fellow researcher Francesco Ferretti say they found that the risk of a great white shark attack for individual ocean users in California has fallen by over 91% since 1950. To arrive at that figure they looked at the number of reported great white shark attacks that caused injuries on the California coast from 1950 to 2013, as recorded by the Global Shark Attack File.

During that time there were 86 attacks, with 13 of them being fatal. They weighted the numbers with information on coastal population growth and seasonal and weekly beach-going, surfing, scuba diving, abalone diving, and swimming.

The number of attacks has actually increased over the years, but the scientists attribute that to the fact that there are a lot more people in the ocean – not necessarily more sharks.

For example, they argue that three times as many people live in coastal California now than in 1950. The 7,000 surfers in 1950 became 872,000 by 2013. Certified scuba divers grew from about 2,000 at the beginning of the 1960s to about 408,000 in 2013.

Avoiding sharks

The study also looks at when and where shark attacks take place, offering guidance for swimmers who want to avoid them.

"Doing this kind of analyses can inform us on hot spots and cold spots for shark activity in time and space that we can use to make informed decisions and give people a way to stay safe while they are enjoying the ocean,"

For example, in the fall there is a higher chance of finding big white sharks on the California coast than in the spring, when they migrate to Hawaii, said Ferretti. He points out that the chance of a shark attack increases at night. 

The authors say that in Mendocino County, Calif., it is 24 times safer to surf in March than in October and November. If surfers choose the coast between Los Angeles and San Diego in March, they can be 1,566 times safer than they would be during the fall months in Mendocino.

Meanwhile, the reason for eight shark attacks along North Carolina's beaches this summer remains a mystery. According to National Geographic, warmer water and ocean currents may have attracted smaller fish, which in turn attracted sharks. But the magazine states that it's probably due to more humans being in the water.

In North Carolina, evidence is piling up that suggests there are also a lot more sharks in the water. Charter boat captains interviewed by the Richmond Times-Dispatch say there is now an over-population of sharks off the Carolina coast that has been building for years.

Some tuna fishermen say they are only able to boat half their catches before they are at least partially eaten by sharks.


Share your Comments