The Mystery of Shark Attacks

University of Miami

By David Aaro

On Wednesday July 27, 2016 a 43- year -old man was attacked by a four- foot nurse shark, needing medical attention about seven miles from the shores of the Florida Keys. While lobstering in nine feet of water, the man and the shark went for the crustacean at the same time, when it bit him. He was given medical attention by Two Conchs, a charter boat out of Marathon Florida, captained by John Carlson. “We bandaged it up, put some gauze on there, some black electrical tape and hit a couple more spots, then headed in,” Carlson said.

For the sports fans out there, you might remember NFL Hall of Fame defensive tackle Warren Sapp tweeting out Shark-1 Me-0. This was his story.

Picture3All of this information is easily accessible thanks to the Global Shark Attack File(GSAF), a database that provides historical and current data on shark and human interactions. Their goal is to understand our relationship with what many depict as violent predators. They have a team of over 40 investigators that have tried to capture every shark attack that occurs since the early 1900’s. Sapp’s story is case number 2016.07.27 in a dataset of thousands of recorded shark attacks. By clicking on that case number you are able to access all of that information above, as well as a description of the person, picture of the attack bite, location where it occurred and a link to the newspapers who covered the attack.


That wealth and depth of information, no pun intended, is what makes the Global Shark Attack File unique says Ralph Collier, the director of the GSAF. “Our website will show you day by day since first of this year every incident chronologically, the name of person, location, what they are doing, a brief description about what happened and was it fatal, says Collier. “You go to other sites and all they do is give you numbers, what happened and that’s it. You can see what happened and even access a photo of the victim from a PDF.”

He believes you can’t truly understand what happened during an encounter unless you talk with the victim and get all the details surrounding the event. He believes that extra research helps to uncover the true story of why the shark attacked. Was it provoked? Could it have been prevented?

Sapp’s encounter was one of two provoked attacks in Florida during 2016. A low number because most of the time the attacks are unprovoked. There were 33 unprovoked shark attacks recorded in Florida, in 2016, thanks to its endless beaches, tourism and water activities that people partake in every day. Florida proportionately had most unprovoked attacks in not only the United States, but the world. According to the GSAF data, 60.5 percent of all shark attacks in the United States occur in Florida. In fact, Florida is home to 28 percent of all worldwide attacks. The 2016 total of 35 Florida bites was a bit higher than the 2015 total of 30 and well above the recent five-year average of 23.8. The record high was 37 attacks in 2000.

Thanks to news coverage, movies and TV, many people have the idea that sharks attacks happen all the time and these creatures are mindless killing machines. Many people also feel that when a shark bites you, there is a low chance of survival. By analyzing data in Florida the goal is to find out if that really is the case, and understand what factors can limit or promote shark attacks.



Figure 1: Blue= Shark Encounter, Red=Fatal Attack


Since 2010, there have been between 97 to 138 shark attacks each year worldwide. The high being 138 in 2015 and a low in 2010. The highest number of fatalities in a single year was 17 in 2011. Even so, that year only 13 percent of all shark attacks resulted in death. This shows just how rare shark attack fatalities really are. Only 9% of shark attacks were fatal over the past six years with 851 total shark attacks and 77 fatalities.

 “On average you have less then 10 percent worldwide are fatal, when you look at the total numbers,” Collier said. “Usually in areas that get 90 to 100 shark attacks you have about 7,8,9 attacks that will be fatal. Some years that number is high and some years you don’t have any.”

It’s hard to determine why some years have more attacks than others because of how cyclical the data is, says Collier. Some years there may be no fatalities and less than 90 attacks in the world, while others years may have 120 attacks and 9 to 10 fatalities. He says after 50 years covering sharks that it’s still a mystery to him, but that’s also why he continues to study them.

Collier says Florida is especially very hard to monitor, as there are so many factors that determine why shark attack encounters occur at a higher rate there, compared to the rest of the world. The first is population dynamics. More people in Florida are using the water compared to other areas. They have the most coastline out of any state in the U.S. and much of its population, like Australia, is along the coastline. This means more people are using the water. Also unlike California, which also has a lot of coastline, the water in Florida stays warmer for longer periods throughout the year. Water in California gets in the 50’s during the winter, so less people will be in the water. While shark population has decreased over the past twenty years due to fishing, there are still the same amount of attacks because more people are using the waters.

Shark data is also hard to monitor in Florida, because the species are more numerous compared to other areas in the United States says Collier. For example, in California there are only white sharks due to the large seal population on the west coast. Florida doesn’t have the luxury of having a single prey that researchers can track to monitor those attacks. It makes it harder to track, because a lot of times to track the shark, you need to track the prey. Another reason he says they are hard to track is victims don’t usually know what a specific shark type looks like. When this is the case they use bite marks on the victim/surfboard and teeth spacing to determine what it might be, however it’s not always reliable. He says most of the attacks occur during the three -month period of July through September when most people are using the water.

Curator and GSAF researcher Marie Levine says that one of the main reasons for shark attacks in Florida is shark feeding. Much of that happens near crowded piers, which is one of the main reasons Florida wants to ban shark feeding. “Research told us time and time again the danger of allowing surfing and beaches next to fishing piers,” Levine said.

As an investigator herself, she remembers an attack on an 8 –year- old boy in Virginia Beach that happened a quarter mile from a fishing pier. There was evidence of shark fishing near where the child was, due to the high water mark and shark hooks. She says those hooks are very expensive and people would have retrieved them if they were found. This indicated that fishing had been going on at night.

Being an investigator can shed light on shark attacks, and she says it can also be hard seeing the aftermath of a shark attack first hand. Unlike some media outlets who are there for a flashy story, she wants to understand the victims story and help any way she can. Some of those memories she had meeting with victims in the hospital stay with her.

“I remember this young woman Belinda in the 1980’s, I went to the hospital to talk with her and even now have stayed in touch, Levine said. “I still remember her putting her hand in the wound and artery in the hospital and saying how she knew on the beach she would lose it. She wanted to be a model, but after the incident had to go into fashion design. I made sure to stay in touch because what I do is for people like her.”

The GSAF admit that it’s hard to track every single shark attack. They have over 40 researchers worldwide, but there are some parts of the world that either don’t track shark attacks, or don’t want them known due to tourism reasons. Yes, I know…. that seems right out of the movie Jaws with Mayor Larry Vaughn, who decided to keep the beach open for fear of losing tourism dollars. Evidently that actually happens.

“Generally high tourism areas don’t like to publicize any shark attacks in the area if it’s based on utilization in the ocean,” Collier said. “Indonesia kept quiet and there was no publicity in Mexico or Acapulco. There are also shark attacks that occur somewhere in the world in an out of the way location like a pacific island or in the Caribbean where they just don’t report it.” The way of reporting those attacks has also changed over time.

Because Collier and Shark Attack File have been recording shark attacks since before the 1980’s they say the ways of investigating and finding out information about shark attacks have changed dramatically over the years, some for better and some for worse. Back in the day he had to get ahold of friends in the Fish and Game industry in California and they would then forward him to local lifeguards. It was a process of elimination with dozens of phone calls just to get the name of the individual. Today he says with the internet you can just type shark attack, the area you want and find everything you need to know.

On the other hand, he says privacy laws today make it harder to gain information on a more personal level. “Years ago when someone was bitten I could call the hospital, tell them who I was and what my interest was, Collier said. “They would put me on hold for two to three minutes and put me through to get copies of medical records and photographs the doctor took of the injury. Today you can’t have any of that because of privacy laws.”

He says today you have to have the person sign a release form before you can even speak with the victim. That makes it harder to get on a more personal level with the victims like they had in the past.

One of the main pieces of info they get from investigating the victim is whether the attack was provoked or not.



Figure 2: Blue=Unprovoked, Red=Provoked


Nearly 95% of all shark attacks were not provoked. This shows the danger isn’t whether you provoke the shark, but whether it thinks you are its next meal.  Most of the time you get attacked by being in the wrong place at the wrong time. He says there are three types of encounters you can experience with a shark and three reasons they might attack you.

Those types of encounters are non -physical, where it doesn’t attack you, provoked, where you do something like poke its tail with a spear, and unprovoked where you do nothing to have the shark reach out. While these are general types of encounters, he says sharks tend to bite you for different reasons.

The three types of attacks are investigative, if the shark thinks you might be food, predatory if they have high energy and want to kill its prey, and displacement, where the shark perceives you as a threat to its territory. investigative usually ends up with the victim sustaining a few minor cuts, while predatory and displacement can end in serious injury. Most of these can occur even if not provoked. “Shark attacks occur not because of what the person is doing, Collier said. “But where they are doing it.”

In conclusion, even with all this data at the GSAF disposal, shark attacks are a mystery even through years of research and study. Nearly all attacks are unprovoked, where the shark either thinks you’re its prey, or you happen to be in the wrong place at the wrong time. Most of the attacks however aren’t fatal, as only 10 percent of all shark attacks result in death. It’s usually the shark testing to see what you are.

Thanks to its vast coastline and large portion of the population that practically lives in the water, Florida is home to the most shark attacks not only in the U.S., but worldwide. Legislation also needs to be created in Florida to limit shark fishing near beaches where people swim and surf, as that’s one of the main reasons for shark attacks in that area.

Because of research and places like the GSAF, shark attacks will continue to be monitored. The hope is that one day we can find out how to prevent these attacks and understand in greater detail one of the oldest creatures on planet earth.


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