Shark attacks like the one that killed a young surfer on Sunday are rare, but according to experts, they're only going to increase in number. In fact, the rate of "unprovoked" shark attacks has been steadily rising for the last century. No, sharks aren't developing a particular taste for humans: It's the expanding human population that's actually to blame. "If we look at the number of shark attacks in any given place in any given year and compare that to population growth in those areas, we find that shark attacks match the growth curve of the human population in that region," shark researcher George Burgess tells NBC News. Meanwhile, the human population will near 11 billion by 2050, while some shark species are also growing in number in light of efforts to thwart overfishing.
At the same time, water activities are more popular than a generation ago, sending humans into shark turf, Burgess writes at the Conversation. "More sharks and people are likely to be in close proximity to one another, leading to more attacks," a Florida State University researcher says, noting the number of attacks per 100,000 beach visitors remains stable. Of 72 unprovoked attacks in 2014, 52 occurred in the US, though less than one person dies in the US from shark attacks each year on average, compared to six deaths worldwide, LiveScience reports. Burgess says he's "confident" attacks will become more common in the next 15 years. If you'd rather avoid a shark encounter, don't swim at dusk, dawn, nighttime, or near where someone is fishing. And leave flashy jewelry on the beach; sharks may confuse shiny pieces with fish scales. (A fisherman's rare catch: a shark with 300 teeth.)