The Thing About Sharks

The recent attacks on swimmers in North Carolina have once again brought up the topic of sharks.  And of course, “Shark Week” is coming up.  It is understandable why people are concerned about swimming in waters were animals weighing several hundred pounds with rows of sharp, sometimes serrated, teeth are lurking.  It is also understandable that local tourism groups are concerned that visitors are concerned.  Sounds like the movie Jaws all over again.

The blacktip shark is responsible for many shark attacks in the coastal waters of Florida.
Photo: University of Florida IFAS

So, what is the risk?

 

It is good question to ask for anything we feel uncomfortable with.  Hiking in Rockies where bears might roam.  Hiking in wetlands of Florida or deserts of the American southwest where venomous snakes may lurk.  Paddling the creeks and rivers of the American southeast where alligators could be basking.  All are concerns.

 

According to G. Tyler Miller and Scott E. Spoolman, a risk is the probability of suffering harm from a hazard that can cause injury, disease, death, economic loss, or damage.  There is a difference between possibility and probability.  There is always the possibility of a shark attack, but what is the probability it will happen?  Unfortunately, media blast can create a scare over a highly unlikely possibility without discussing the data driven probability of it happening.  We all take risk every day – riding in a car, smoking, drinking alcohol, eating bad food – which can lead to heart issues and the number one killer of humans worldwide, and more.  Many of these we do not consider risky.  We feel we are in control, understand the risk, and are managing from them.  Those risk we have little control over – shark attacks – seem more of a risk than they really are.  The car is far more dangerous, yet we do not hesitate to get in one at zoom onto the interstate.

 

Let’s conduct a simple risk assessment of shark attacks…

 

What is the hazard of concern?

Being attacked by a shark

Dying from the shark attack

 

How likely is the event?

The International Shark Attack File was first developed after World War II to address the issue of shark attacks on US Navy personnel, but expended to everyone.  It was originally housed at the Smithsonian Institute but is currently housed at the Florida Museum of Natural History in Gainesville.  Based on their records of unprovoked shark attacks (the ones we are truly interested in) there have been 3103 attacks on humans since 1580.  46% of those were in the United States, ranking us #1.  Number two and three are Australia and South Africa.  So as far as nations go, we are number one for attacks.  However, this equates to 7 attacks / year – worldwide.  And not all of those died.  Most did not.

 

Which state?

Since 1837, 828 attacks (57%) occurred in Florida.  This equates to 4.5 attacks / year.  Florida is number one, followed by Hawaii and California.

 

What about counties in Florida?

Since 1882 there have been 303 attacks (36%) in Volusia County.  This equates to 2.2 attacks/year.  The total number of attacks in Florida panhandle counties since 1882 have been 25 – this is 0.2 attacks/year for the entire panhandle.

 

What were these Floridians and visitors doing when they were attacked?

Surface recreation (surfing, boogie boarding), swimming, and wading top the list, the other activities were logged.

 

So, there have between 8-10 shark attacks each year, and two fatalities, worldwide. 

The bull shark is a species who is responsible for many attacks in the Florida panhandle.
Photo: University of Florida IFAS

The Risk Assessment is used to develop a Risk Management Plan

First, How do these shark attack data compare with other risks?

 

I wondered how many car accidents occur each year worldwide?

According to USA Insurance Coverage, who got their data from the National Highway Traffic Administration – 5,250,000 each year in the United States alone.  About one every 60 seconds.

 

Situations that cause human deaths annually in the United States

Heart disease    652,486              1 in 5 people

Cancer                553,888              1 in 7

Stroke                 150,074              1 in 24

Shark attack      1                           1 in 3,748,067

 

Between 1992-2000 there were 2 shark attacks in Florida.  In that same time period, there were 135 drownings.

 

Between 2004 and 2013, 361 people drowned in rip currents.  During that same period, 8 people were attacked by sharks.

 

Between 1990 and 2009, in Florida, 112,581 people were involved in bicycle accidents; 2272 died.  In that same period, there were 435 shark attacks in Florida; 4 died.

 

And my favorite…

Between 1984 and 1987, 6339 people had to visit a hospital in New York City because they were bitten by a human.  This was 1585 / year.  In that same period there were 45 shark attacks in the entire United States.  This was 11 / year.

 

Second, How should we reduce the risk of shark attack?

Well… as you can see from the assessment and comparative risk analysis, many would say you did not need to develop a plan to reduce risk because the risk is too low to fool with.  You should spend time on hazards that are of a more real concern.  That said, there are some things you can do.

–          Avoid excessive splashing; it is known that sharks are attracted to this.  It is also known that more often than not, they move away when they detect the source of the splashing.

–          Avoid swimming when bleeding or in water with strong smells (like fish bait); this too will attract them.

–          Most unprovoked attacks occur between 11:00 AM and 3:00 PM.  But honestly, that is when most people are in the water.  This could be different if most of us swim after sunset.  That said, we recommend that you reduce swimming at dawn and dusk.

I hope this clear up some of the concerns about shark attacks.  Yes, they do happen – but infrequently.  There are some things you can do to reduce your risk, but these should not keep you from enjoying water related activities.  Enjoy your time here on the Gulf coast.  Be careful driving and try to eat healthier.

 

References

 

International Shark Attack File.  https://www.floridamuseum.ufl.edu/shark-attacks/.

 

Miller, G.T., S.E. Spoolman. 2011. Living in the Environment. 16th Edition.  Brooks and Cole, Cengage Learning.  Belmont CA. pp. 121.

 

USA Insurance. https://www.usacoverage.com/auto-insurance/how-many-driving-accidents-occur-each-year.html.