Why shark attacks could be on the rise around the world

In 2016, 107 people in different parts of the world were bitten by sharks. Eight of those 107 people died.

While 107 may not seem like a large number when you are talking about a global issue, when it comes to shark and human interaction, that many "unprovoked" attacks means it was a record-setting year.

The International Shark Attack File, the longest maintained database on worldwide shark attacks, said it investigated 164 reports in 2015. The group classifies an "unprovoked attack" as an incident "where an attack on a live human occurs in the shark's natural habitat with no human provocation of the shark."

A study released by the group blamed warmer waters and a jump in coastal population for the spike in numbers. The study said, in part:

“As world population continues its upsurge and interest in aquatic recreation concurrently rises, we realistically should expect increases in the number of shark attacks and other aquatic recreation-related injuries …

“Shark populations are actually declining or holding at greatly reduced levels in many areas of the world as a result of over-fishing and habitat loss, theoretically reducing the opportunity for these shark-human interactions.

“However, year-to-year variability in local meteorological, oceanographic, and socioeconomic conditions also significantly influences the local abundance of sharks and humans in the water and, therefore, the odds of encountering one another.”

Let’s take a look at some numbers.

Are there really more attacks happening?

When you talk about shark bites, researchers say you have to look at the ratio, not the numbers. In other words, are more people bitten by sharks because more people (and maybe more sharks) are in the same water?

"More people are using the ocean now for recreation than ever before, so there is no doubt that we're putting more people in the water," Chris Lowe, a professor in the Department of Biological Studies at California State University, Long Beach, told Men's Journal last year.

"And while there isn't a lot of good scientific evidence for this yet, I think that some shark populations are increasing due to better fisheries management and improved water quality," he said. "You put more people in the water and add more sharks to coastal areas, you will have more shark-human related interactions."

Professor George Burgess, director of the University of Florida Program for Shark Research, told The Telegraph in a story about 2015's spike in shark bites, "Unlike in the movies, it's not usually a one cause and effect type of a situation. More often it's a combination of factors that might have led to there being more sharks or more humans in the water, but this is clearly a situation where there is something going on."

What are the odds?

How likely is it that you will be bitten by a shark? Not likely at all. A group of researchers at Stanford University compared records of shark bites with information about how people use the ocean in California. The study found that an ocean swimmer had only one chance in 738 million of being bitten by a great white shark; surfers had a one in 17 million chance, and scuba divers had a one in 136 million chance.

Who do they attack?

Sharks will likely bite the person who acts like a fish or looks like a seal. If you appear to the shark as his normal food choice – by being on a surfboard, looking sort of seal-like, or splashing around like a fish – he’s more likely to go for it. Humans are generally not on his menu.

Where do they attack?

The United States leads the world in unprovoked shark attacks. Florida leads the United States. While there are more shark bites in the United States, if you are bitten here, you are more likely to survive the bite. The fatality rate for shark bites in the U.S. in 2014 was 1.7%. For the rest of the world, it was 12.8%.

Could we see an increase in shark bite incidents again this year?

We could. If current trends continue, the U.S. coastal regions will see their populations grow from 123 million people to nearly 134 million people by 2020, according to National Oceanic and Atmospheric Adminstration. That doesn't include the millions who vacation on the coasts every year.

Who is most likely to get bitten – man or woman?

Sharks don't seem to prefer the ladies as 90 percent of shark attack victims are men. It's the ratio thing in play again. Traditionally more men are swimming, snorkeling and surfing – activities that expose you to the greatest risk for shark attacks.

Which sharks are responsible for most human bites?

Three species are most responsible for human bites – the bull shark, the tiger shark and the great white shark.