Dangerous? | sharkworld

On the contrary to most people's belief, only a few sharks can be dangerous to humans.

As a matter of fact, sharks are afraid of us; they sense our energy.

On average, sharks kill 3 humans per year (that is less than vending machines)
Elephants kill about 300 per year
About 600 people die because of dog bites each year
There are 2400 executions on average per year
Drug related deaths: 22'000 per year
Traffic accidents: 1.2 million
Mosquito related diseases: 2.7 Mio
Hunger: 8 million persons a year

Sharks don't like human flesh for it has too little fatty acids. Being picky, sharks first two times "taste" the potential prey, they bite into it, but don't rip flesh out. Only if they like it will they eat it. This is also the reason, why in most shark attacks, a person only has been attacked once and no flesh was removed. The deaths ususally are due to blood loss, not the bite itself.

Tourists each year go bathing and conduct other leisure time activities in the waters where sharks are known to hunt and still there are only that few incidents. This is due to the "self-disciplin" of the sharks.

Would you go jogging when there are 50 hungry lions right next to you? Probably not.. but we're doing it with the sharks every season...

Aggression towards humans:

There are only two reasons why a shark would be aggressive, and it usually are direct or indirect human activities that drive the sharks:

They try to defend their territory: especially female sharks that are about to give birth.

They get a stimulus of food. Usually the shape of a surfer looks like a seal or a turtle that both - as opposed to humans - are on the menu of sharks. During the attack sharks close their eye lids to protect their eyes and hence can't see what they're biting into.

When boats near the beaches or other places where people are in the water throw out their trash, it attracts the sharks.

Finally, due to overfishing of the sharks' prey, they have to go and look for food where they usually wouldn't go... from time to time this happens to be where tourist are...

Some statistics

Species of shark implicated in confirmed unprovoked attacks around the world, 1580 - 2011

Source: http://www.flmnh.ufl.edu/fish/sharks/statistics/species3.htm

Figure: Attacks and Fatalities of different species of sharks on humans over the period of 1580-2011, globally

Source: http://www.flmnh.ufl.edu/fish/sharks/statistics/Act.htm.

Figure: Shows the number of attacks on Surface Recreationists per decade. The increase in the latest decades is not due to the sharks being more aggressive, but because more and more people practice surface recreation (and go the the beach in the first place)

Source: http://www.flmnh.ufl.edu/fish/sharks/White/World.htm.

Figure: Different territories of the world with 1876-2011 world's confirmed unprovoked Attacks by White Sharks (N=263)

This graph shows that sharks truely are not after humans at all: 151 fatal attacks in 431 years, that's an average of 2.8 killed humans per year worldwide. Due to better emergency organization and medical development, the fatality rate after a shark attack has dropped from 0.6 in the 1900s to 0.05 in the 2000s.

In the year 2011, there were 90 million people conducting water activity.

But: Great Whites do attack surf boards more often. This is because they look at the silhouette from below; and surfers do look like pinnipeds (the shark's actual prey).

However, a lot more surfers die for example from drowning than being bitten by a shark.

It is true that sharks are excited by blood. They can smell it from far away. During the blood frenzy sharks will attack anything, even their own species. Some sharks even get bitten to death in such attacks.

Another reason for the slightly increased attack rate in the last few decades is thought to be the "Cage Diving Experience" that some divers seek. It has been argued that in these types of tours the sharks (Great Whites) are attracted with bait for the cage-divers to see them feed. This can lead to the shark losing its instinctive fear of people and it can also lead to the shark associating human presence with feeding... This is return can lead to a higher attack rate.