The International Shark Attack File released by the Florida Museum of Natural History says the cause for the uptick in attacks is simple statistics: more sharks are biting humans because there are ever-growing numbers of people in the ocean, increasing the opportunity for interaction between the two species.
The Florida Museum of Natural History (in the home state of the most unprovoked shark attacks in the US per year) takes some credit, too, for the rise in recorded attacks. It reports that in the past 25 years the group has become more efficient at discovering and investigating attacks which has led to further increases in the number of recorded interactions.
Frank J. Schwartz, a shark biologist from the University of North Carolina at Chapel Hill, told National Geographic that attacks are heavily dependent on weather and currents. Two conditions, both of which occurred in North Carolina as early as April and have since persisted, are water temperature reaching 80 degrees Fahrenheit and strong currents flowing north along the coast, bringing shark bait along with it. Sharks follow these conditions, Mr. Schwartz said, coming from Florida and the Gulf of Mexico.
But Schwartz warned against statistical analysis of shark attacks. Incidences are so rare that it is difficult to identify trends or correlations. Similarly, water temperatures and currents fluctuate so much from from year to year, Schwartz said, that it is unclear whether climate change has anything to do with shark behavior.
To avoid being bitten by a shark, Schwartz recommends not behaving like prey and minimizing confusion. Sharks can mistake humans for food when visibility is low. If you are worried about sharks, stay clear of the water when it is particularly choppy and the water is murky.
Avoid splashing or wearing anything shiny, which to sharks can resemble the scales of a fish.
Schwartz told National Geographic that most attacks are simply the result of “being in the wrong place at the wrong time.”
“Usually there is bait nearby and someone just gets in the way,” he said.
The International Shark Attack file points out that worldwide only three fatalities resulted from unprovoked attacks in 2014. Shark-related fatalities have been on the decline in the last eleven decades, even as records of attacks are on the rise. The report claims that the total deaths is “remarkably low given the billions of human-hours spent in the water each year.”