Shark attacks were down last year, both in Florida and worldwide

Climate change may be a factor, but the Sunshine State is still the global leader.

A bull shark swims in the waters near visitors to Miramar Beach. [Associated Press photo]
A bull shark swims in the waters near visitors to Miramar Beach. [Associated Press photo]

Worldwide reports of sharks biting people fell dramatically in 2018, thanks in large part to a drop in Florida, according to newly released figures from the Florida Museum of Natural History’s research program.

Sharks bit 66 people around the world last year, down from 88 in 2017. It’s also 26 percent lower than the most recent five-year average of 84 bites.

“That's quite a drop,” Gavin Naylor, director of the museum’s Florida Program for Shark Research, said Monday

In Florida, the bite tally fell from 31 in 2017 to 16 last year. (The all-time Florida record: 37 in 2000.)

Despite its image as a vacation paradise, Florida frequently leads the world in the number of shark bites, as well as leading the nation in fatal lightning strikes, sinkholes, pedestrians run over by cars and hurricanes making landfall. Volusia County in particular is the shark attack capital of the world. Four people were bitten in Volusia last year, compared to nine the year before.

Blacktip sharks, Carcharhinus limbatus, commonly cruise the surf zone of Florida s Atlantic coast in pursuit of fish. They often mistake humans hands, feet and legs for their targets. [Florida Atlantic University photo]

Other locations that recorded lots of bites included Australia, with 20, one fatal, an increase from the country’s recent five-year average of 14 bites annually; Brazil and Egypt both reported three bites and one fatality.

Why did shark bites in Florida drop so low compared to the previous year? Naylor has a theory involving warmer ocean temperatures and the effect on shark migration.

Most of the people bitten by sharks do not know what species clamped down on their hand or leg, he said. But DNA tests and other evidence indicates that many, if not most, come from blacktip sharks.

Blacktips feed on schooling fish in shallow water, he explained. When they see movement in the water, they strike quickly. Sometimes they accidentally chomp on something other than a fish — a swimmer’s fluttering fingers, or an ankle dangling from a surfboard.

The blacktips migrate back and forth along the Atlantic coast, from Virginia and the Carolinas to Florida each year. Stephen M. Kajiura, a scientist at Florida Atlantic University, has spent the past decade keeping tabs on that migration when it reaches Florida.

A school of blacktip sharks swims south along Palm Beach in March 2016. The sharks migrate to southeast Florida in the spring and fall, and return to the Carolinas and Virginia in the summer. [Florida Atlantic University photo]

Usually he sees 15,000 blacktips along the Florida coast, but he said that number has slowly dropped over the past six years. Last year, it hit 5,000 sharks, the lowest number ever.

The suspected reason, Kajiura said, was warmer water temperatures in the ocean. The warmth meant the sharks didn't have to go so far south and didn't wind up in the same place with thousands of swimmers off the Florida coast.

Naylor said he is not sure he would attribute the sharks’ altered migration to climate change. But Kajiura said the warming of the globe explains the warmer ocean temperatures that are influencing what's been called the largest migration in U.S. coastal waters.

On the other hand, Kajiura is not convinced there is a correlation between the shark migration and the number of bites.

“It’s an intriguing idea,” he said, “but I just don't have the data to back it up.”

This article was originally published in the Tampa Bay Times on Jan. 28, 2019.

Craig Pittman is the environmental reporter at the Tampa Bay Times. A native Floridian, he is the author of several books about the state.