Why do sharks attack people?

Ok, if you have not heard the news, yesterday in Vero Beach close to where we shore dive, there was a shark attack on a German tourist. She was bitten on the upper thigh and was rushed for emergency surgery. At present she appears to be in stable condition. Fabulous and fast rescue by local lifeguards Erik Toomsoo,Jordan Farrow and Shanna Beardo.


This got me to thinking as already the hysteria is starting. Rich called to tell me in the last 1/2 hour, 2 different customers told him about the shark attack. The effect the media has on the average Joe’s perception of the shark is generally negative. Add in Jaws and you get my point.
From 1882-2011 in Florida, there have been 637 total attacks. 11 of which were fatal. That is in almost 130 years. Worldwide about 60 shark attacks occur.
Next, on average shark attacks kill 10 human being a year. While humans kill somewhere between 20 and 30 million sharks. Because of this tiger sharks and hammerhead sharks are now endangered and protected in Florida.
Nevertheless, sharks do result in human deaths and do cause injury to some beach goers.

So, why exactly do sharks attack people on the shore?
Sharks are the top dog (apex predator) in the sea and therefore have very little fear of other creatures in the sea. Curiosity mainly causes them to check out what is in their hunting territory. They do not have arms or legs so their main way of exploring an unfamiliar object is with a bite. Scientists call this an exploratory bite. Generally after the nibble, they realize you are not what they are looking for and they swim off. Sharks, of course, have extremely sharp teeth so these exploratory bites can be harmful and even fatal. While the bite may not kill you in an instant. the bite may cause a human to bleed to death.

nurse shark

Sharks also have sensory organs called the Ampullae of Lorenzini. These organs detect the electricity generated by human muscle movement. These organs may cause sharks to attack fishermen by accident when they sense the signals given off by a wounded fish they have caught. I can tell you that the boys at Gold Coast scuba had a fish they had speared and were bringing it up when a big nurse shark came up and almost got one of them. Now nurse sharks are generally passive but this was at night, injured fish on the line bleeding and sending off signals and WHACK, tasty treat. Needless to say, they will not be petting nurse sharks in the future. I am not sure if I had heard this story before I got up close with the last one to video, I would have gotten as close as I did.

Sharks are highly territorial so if there is another shark species in his hunting turf, they may be overly aggressive. Think tiger meets bull shark. Turf war. Humans may just be caught in the middle.

With the sharks rapid decline in population, why are the attacks on humans are staying steady.

Humans are encroaching into the sharks territory more and more every year. With water sports becoming more popular like surfing, wave boarding, kayaking and even swimming, we are in the oceans a dramatic amount more than 20 years ago. Wikipedia has stated “Even if the food-human link is indirect, it likely explains most shark attacks in general. The National Oceanic and Atmospheric Administration (NOAA) explains that sharks do not normally hunt humans, but if they do attack, it is usually a case of mistaken identity. Assuming a large, predatory shark has not been exposed to human flesh before, it is probably used to biting into thick-tissued, fatty sea lions, seals and similar-bodied prey. Sometimes sharks will investigate potential food items by taking a taste. Unfortunately, given their many rows of sharp teeth, a few shark species can cause an individual to bleed to death after a single bite. The problem is compounded in lakes, rivers and estuaries, where freshwater sharks, such as bull sharks, often share water space with humans who are swimming, boating, fishing or engaged in some other form of recreation that might put them face to face with a shark.”

According to scientists, there are four basic types of shark attacks on humans. The most common are provoked attacks. These shark attacks happen when people touch or disturb the sharks. Think dumb ass diver touching a nurse shark tail. Perhaps a fisherman removing sharks from their nets, coming into contact of its mouth when it rips around quick. The shark is distressed from being in the net or on the hook and he is aggressive.

Unprovoked shark attacks can happen in three principal ways.
1. Hit & run – when the shark grabs, releases and leaves the scene. The shark could be investigating the individual, thinking he or she was its usual prey. It might also perceive the individual as a threat, similar to how a more aggressive, yet fearful, dog could attack anyone who mistakenly treads on its turf.
2. Sneak attacks – when a diver gets caught unaware by a stalker.
3. Bump & Bite – when a shark head-butts a person before it takes a bite.

In all reality, sharks really aren’t looking for a human meal. You are not flashing a neon sign that says eats me. There are plenty of other fatty fish, they would prefer. You are not a fat rich diet for them. Well perhaps some are! Also when they are feeding, shark habits are to make one swift attack and then retreat and wait for the meal to die or tire itself out. They do this to protect themselves from the feast if it gets aggressive. This is also good news for human who may come up against them by giving them time to get out of the water before a second bite.

George Burgess, director of the International Shark Attack File, said the following regarding why people are attacked: “Attacks are basically an odds game based on how many hours you are in the water”. Makes sense to me. Go to the beach a lot and wade in the surf, you will see sharks more.

If you are freaked out by the reports of shark attacks, how can you minimize the chance of a shark attack?

Stay in groups in the shoreline. There is safety in numbers. Sharks tend to attack individuals that they feel they can overcome.

Avoid being in the water during early morning and late afternoon. Sharks actively feed at those times.

Never go into the water if you are bleeding, even if the cut or injury is minor. Sharks possess very keen senses, and blood could attract one from several feet away.

Don’t wear shiny jewelry when in the water. The sharks may mistake this for sparkly fish scales.

Stay away from sport or commercial fishermen when in the water, as their catches could attract sharks. The usually have bloody bait or attractive fish the shark wants. The fish caught may be injured and sending off signals.

Avoid wearing brightly colored clothing in murky waters. Sharks can tell color difference and as you may know from my many pictures, reef fish are brightly colored.

Don’t overly splash. The sharks may think these are disoriented or injured fish or animals.

Sandbars, steep drop-offs and estuary inlets tend to be shark hangouts, so avoid swimming in these places. This is funny to me, as everyone heads for the sandbar not realizing that deeper water behind may harbor a feeding shark. Also, the major attacks I see around here happen in inlet areas.

If you actually see a shark getting ready attack, do you know what to do? PUNCH IT BETWEEN THE EYES! Really, and if you are diving carry a dive knife. I have two, never wear them because hubby has a humungous one. ( I could make some sort of comment here but I shall keep very quiet) If you are diving, get to the bottom and stay with your dive buddy. You look bigger together. If you surface, you appear to be a fish from the top and this is one of the main reason surfers get attacked on their boards. They float.

Please, in no way am I trying to minimize sharks attacks. I am thankful that we have incredibly fast responsive lifeguards locally. However in my opinion, our greater fear should be that sharks will become extinct. Many studies and reports on reef systems show that these creatures play a vital part in keeping the order of the reef.

Knowledge is power. If you are afraid of sharks, ask yourself why? Respect the shark and his territory and don’t do stupid things that could provoke them or draw attention to yourself.

About daniellesdives

diving enthusiast
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6 Responses to Why do sharks attack people?

  1. Thank you Danielle for this very informative post about sharks!

    I tend to consider sharks as beautiful animals which are always sleeping! At least most of Black and white tip sharks I’ve seen in Indonesia were doing so most of the day… but I should say, even very excited, I kept good distances with the hummer-head shark I met in Cozumel, Mexico… I understand that the stories from your friends makes you even more careful. But they are animals… and even while trying to defend themselves they can be aggressive and dangerous, it doesn’t mean we should’t protect them!

  2. Thanks for your speedy and fast thinking in helping this lady out. We appreciate and understand how important a lifeguard is on the beach. Keep up the good work!

  3. Pingback: Chumming & Spearfishing = Great White off Fort Pierce | Danielle's Dives Blog

  4. Shea says:

    Does sharks mean to hurt people

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