Due to their poor visibility, they cannot clearly tell the difference between a surfer and a seal from below.

The great white shark is often portrayed as a ‘brainless killer’ eager to eat a piece of human flesh. Especially in books and movies, sharks are portrayed as the most fearsome creatures. But scientists are increasingly emphasizing that humans are not natural prey; a great white shark rarely deliberately targets a human. And a new study backs up that theory.

shark bites

First of all, we can reassure you: the chance of being bitten by a shark is very, very small. Yet the fear of being attacked by sharks is strong in many people. This public concern has subsequently led to far-reaching measures to contain shark numbers in some areas. “But that also harms other marine life,” says study leader Laura Ryan. “Better understanding will hopefully lead to improved solutions that not only prevent shark bites, but also do not unnecessarily endanger other marine life.”

The numbers
By the way, not all sharks are dangerous to humans. There are more than 300 species, of which only a few are capable of fatally injuring humans. The sharks that can do that are: the white shark (Carcharodon carcharias), the tiger shark (Galeocerdo cuvier), the bull shark (Carcharhinus leucas) and the sand tiger shark (Carcharias taurus). These four sharks account for 69% of all shark attacks. Remarkably, the largest shark species are completely harmless to humans; the whale shark (which can grow up to 13 meters in length), the basking shark (10 meters) and the megamouth shark (5 meters). These species live on small animals (plankton) that they filter out of the water with their large beaks.

In the study, the researchers developed a special virtual visual system, which mimics the vision of white sharks. This allows us to see the world through the glasses of a great white shark. The researchers collected video images of seals and humans and viewed them through the eyes of the great white shark. This gave them a good idea of ​​the sight of these animals when looking up from below.

Poor visibility

According to the researchers, expanding our knowledge about this is very important to better understand why people are sometimes attacked by sharks. “So far, the possible similarity between humans and seals has been assessed based on human vision,” Ryan said. “However, great white sharks see a lot less sharply than we do. For example, they do not see fine details and they are also color blind. Our experiments allowed us to see the world through the eyes of a great white shark.”

Mistake

The study confirms the theory that some shark attacks may very well be a mistake. Because of their poor visibility, the sharks appear to be very difficult to distinguish between swimming or paddling people and seals from below. “While it’s unlikely that every attack on a human is a mistake, it seems very likely in situations where surfers are bitten, who are attacked from below,” Ryan explains.


Watch a shark see a surfer from below in this video. Video: Laura Ryan

For example, a shark sees a seal swimming above it.

young sharks

In particular, young white sharks, which are responsible for most attacks, appear to be regularly mistaken. They are in a life stage where they are just starting to hunt seals and so still have a lot to learn. It is therefore not surprising that they occasionally mistake something or someone else for a seal. “They need to develop a search image for these prey animals and combine that with other sensory information,” said researcher Nathan Hard. “It’s a learning process that sometimes goes wrong.”

Thanks to the study, we are slowly but surely beginning to understand why great white sharks occasionally sink their teeth into humans. And that is probably far from intentional in most cases. The findings from this study have already led to the design of non-invasive, vision-based devices that may help further reduce shark attacks on humans. “They are already being tested at the moment,” Ryan concludes.