Why do sharks attack surfers? A scientific answer to this question | Australian researchers test defense strategies

The Sharks Confuse their usual prey, such as seals or sea lions, With Surfers or swimmers due to poor eyesight, According to a study released on Wednesday.

According to the study published in Facade, Journal of the Royal Society, the problem is that the visual system of shark It is almost insensitive to color and has a very poor ability to distinguish the details of a figure, the resolution of which is six times lower than that of a human.

Why do white sharks mix their prey?

According to researchers, it is worse in young people white sharks, which represents for Surfers The greatest risk of bites.

From A .’s point of view the White shark, neither movement nor shape allow visual distinctions between Theropods and humansThe authors of the article write, noting that their work “supports misidentification theory” to explain some of the attacks.

They also guarantee it shark attacks It is rare – fewer than 60 in the world in 2020 – as indicated by a specialized department at the University of Florida in the United States; The White sharks, tiger and Sardinian sharks often attack surfers.

“Is it The first study Who analyzes this theory from A visual view of a great white sharksaid Laura Ryan, a life sciences researcher at Macquarie University in Australia.

Scientific study process

To test the misidentification theory, Macquarie’s team made “videos captured From the point of view of the shark He processed it with software to imitate his “visual system, and in particular his ability to distinguish shape and movement.

To do this, they taped from the bottom of the pond Sea lion photos and videos – close to the surface, a few meters above the presumed shark, then they compared their movements and morphology with those of rowers, with or without the movement of their legs, in the three main types of surfboards, according to their size.

From the point of view of a small white shark, it is almost impossible to distinguish the cues of a swimmer’s movement or those of a surfer on his board from those of a two-legged shark.

Meanwhile, the researchers will try to determine if “a change in the visual cues of potential prey would be an effective protection method against white sharksRyan said.

He emphasized that solutions should beNot only prevent shark bitesBut also “not to endanger other marine species.”