Why do sharks ‘attack’ humans? More than just mistaken identity…

You may have heard it said that when a white shark attacks a surfer or swimmer in the water, the shark has made a mistake. It has confused its natural food source, a seal or sea lion, with a human. Humans are not on the sharks menu, this has been common knowledge now for many years, but there are still around five or six fatal attacks on humans each year. So why is this happening? Mistaken identity? Or something else. The following is my personal opinion.

When a surfer puts on his/her wetsuit, and paddles out on their surfboard waiting for a wave, you could say the shape might resemble that of a seal on the surface, and that would then reasonably justify why a great white shark would decide to attack a human.

However…
From watching these sharks in South Africa, and spending hours upon hours watching documentaries and reading up on these predators, I have a hard time putting the reason down to a simple mistake in identity. When a great white shark sees a shape on the surface that looks like a seal, it has two options. The first is to attack with full force…

A full on attack occurs when the shark is 100% sure that the object is worth using valuable energy to go for.

  Five or six people die each year from a shark, around 100,000,000 sharks die each year from humans

When this takes place, the one ton fish launches its self vertically from the ocean floor, and hits the seal on the surface at speeds of up to 30 mph. Often this is a very spectacular attack, with the shark flying out of the water, sometimes up to four meters high. The reason for this ambush attack is to protect itself, with the seal disabled in one hit, the shark can keep out of the way of its sharp teeth, and return to consume once the seal has bled to death.

The second is when the shark isn’t completely sure about what it is seeing on the surface, so the shark will slowly swim up from the bottom, and check it out. White sharks have excellent eye sight, and use this sense to get a better idea of what it is they are interested in. But sometimes that’s not enough for a shark, they want to feel what it is. When this happens, the shark will place its jaws over the object, scientists call this ‘mouthing’. The shark clamps down with the same bite force as a human, hardly anything to a shark. The reason for this is to get an idea of what the object is, and if it’s worth pursuing further interest.

This is ‘Trix’ in Mossel Bay, showing her natural curiosity
on our steel cage. She did this three times in the space of half an hour. Photo by Brian Scott.

Its worth saying at this point that white sharks are highly curious animals, they love to know what things are. Working on the cage boat in Mossel Bay, it wouldn’t be unusual for a shark to mouth the propeller, or steel cage attached to the side of the boat. Always done with care and gentleness. Perhaps not words you would expect to hear describing a shark.