Sharks mistake their usual prey, such as seals or sea lions, for surfers or swimmers because they have poor eyesight.
Experts are considering whether a “change in the visual cues of potential prey would be an effective protection technique against white sharks.”
The problem is that the shark’s visual system is almost insensitive to color and has a very poor ability to distinguish the details of a shape, whose resolution is up to six times lower than that of a human being.
According to the researchers, it is even worse in young white sharks, who pose the greatest risk of bites to surfers.
From a great white shark’s point of view, neither movement nor shape allows a visual distinction between pinnipeds and humans.
Likewise, it was assured that shark attacks are rare – less than 60 in the world in 2020, white, tiger and Sardinian sharks are the ones that most attack surfers.
Scientific study process
To test the misidentification theory, a research team made “videos taken from the point of view of the shark and processed them with a program to mimic” its visual system, and in particular its ability to distinguish a shape and its shape. movement.
To do this, images and videos of a sea lion were recorded from the bottom of a pond, close to the surface, a few meters above the supposed shark, and then their movements and shape were compared with those of people who arm, with or without movement. of legs, in the three main types of surfboards, according to their size.
From the point of view of a young white shark, the movement signals of a swimmer or those of a surfer aboard his board are almost impossible to distinguish from those of a pinniped.
The researchers are trying to determine whether a “change in the visual cues of potential prey would be an effective protection technique against white sharks.”
Solutions have to “not only prevent shark bites” but also “not endanger other marine species.”