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Shark Attack Risk Has Fallen Significantly Since The 1950s

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Justine Alford

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clockJul 12 2015, 11:52 UTC
1065 Shark Attack Risk Has Fallen Significantly Since The 1950s
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This may sound paradoxical, but while there has been a rise in the number of people bitten by sharks, the actual risk of being involved in an attack has fallen significantly. According to a new study, the individual risk of a person entering Californian waters being involved in a shark attack is 91% lower than it was in 1950.

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To come to this conclusion, scientists from Stanford University looked at both ocean use by humans, for example swimming or other recreational activities, and shark attack records off the coast of California between 1950 and 2013. Although it’s difficult to determine how much time an individual would typically spend in the water, they found that the chances of suffering a bite in this region are minuscule, but the risk also depends on what you’re doing.

For instance, the minds of scuba divers can be put at ease with a one in 136 million chance of an attack, and while the risk for surfers may be higher, it’s still only one in 17 million. Scuba divers are actually far more likely – 6,897 times, to be precise – to end up in hospital for activity-related medical problems, like decompression sickness, than for being bitten. And those who enter the water are almost 2,000 times more likely to die from drowning than an attack.

The focus of this study may have been California, but that does not necessarily mean the figures do not reflect the rest of the U.S., or the world for that matter. According to International Shark Attack File (ISAF) director George H. Burgess, the findings appear to be consistent with worldwide attack patterns.

If we look at the ISAF’s stats, compiled by the Florida Museum of Natural History, the odds of a shark attack across all U.S. coastal waters in the year 2000 was just one in 11.5 million, but drowning was one in 3.5 million. Now, it’s not necessary to point out the number of injuries citizens sustained from toilets in a year in order to prove a point, but it’s plain to see that the threat of shark attacks is still minor, despite recent reports of attacks that could lead many to believe that they are becoming more commonplace.

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So why have there been slightly more attacks? Quite simply – more people are entering the water. The world’s population is growing all the time, as is the popularity of recreational water sports. As highlighted by National Geographic, the number of people living along Californian coasts has tripled since the ‘50s, meaning there are plenty more swimmers, surfers and divers splashing around.

Although it’s difficult to pinpoint why the risk has fallen so dramatically, the Stanford study suggests that declining shark numbers, in particular great whites, could be playing a role. Alternatively, seal populations seem to be flourishing, meaning sharks have plenty of other prey to focus their attention on.

Even though the chances of suffering an attack are tiny, the chance still exists if you enter the water. So what’s the best way to avoid it? Certainly not culling, the researchers say, which has been shown to have no effect on the risk of an encounter, mainly because those removed tend to be the ones that don’t actually pose a danger to humans. Instead, it would be far better to monitor sharks and determine when and where the safest spots to enter the ocean are, helping people make informed decisions. 

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The results of this study are due to be published in Frontiers in Ecology and the Environment later this month. 


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