Great white sharks can’t distinguish between humans and seals: study

Great white sharks can't distinguish between humans and seals: study

Swimmers beware: hungry sharks Represent You think you are food.

Small white sharks, which are responsible for most attacks on humans, cannot distinguish between humans and seals, according to new research.

MORE: Surfer is still amazing after surviving a great white shark attack

To test the “false identity theory” behind shark bites, researchers in Australia compared video images of typical prey with images of people swimming and pulling surfboards from the perspective of a small white shark.

Photo: A great white shark swims near the surface of the water off Dyer Island in Western Australia, in 2004 (Education Images/UIG via Getty Images, FILE)

The researchers built a virtual optical system based on what is known about the vision of small white sharks and viewed images of swimmers and prey using this filter, said Laura Ryan, a neurobiologist at Macquarie University in Sydney and an author of the study. News. .

More: Researchers say groups of great white sharks are moving increasingly north on the California coast due to climate change

Researchers have found that sharks cannot distinguish between movement signals or the shapes of prey and humans, proving that humans and seals look “dangerously similar” from the sharks’ perspective, according to the study published Tuesday in the Government Gazette. Journals of the Royal Society. The researchers also found that the swimmers and surfers in front of the baby sharks resembled seals with their plucked fins.

Photo: Australian sea lions swim close to humans in Australia’s Shutter Islands Marine Park, in 2011 (Auscape/UIG via Getty Images, FILE)

Sharks have lower spatial resolution than humans, which means they don’t see much detail and are color blind, Ryan said, adding that scientists hypothesize that as sharks get older, they become more experienced hunters and rely more on other sensory cues.

“So it’s possible that these older adults are more experienced and empowered, so maybe they don’t make the same amount of mistakes,” she said. “Even as the animal grows, their eyes get bigger, which means their spatial acuity increases, so they can see more details.”

More: How to protect yourself from shark attacks this summer

Ryan emphasized that researchers were studying “unprovoked” attacks, such as those by swimmers and surfers, while an unprovoked shark attack could be a defensive or aggressive disturbance in response to a direct disturbance by a human, such as hitting a diver with a shark or the body of a person. what. spear. fishing.

According to the study, white sharks, bull sharks, and tiger sharks are the species responsible for most injuries and fatal bites.

Photo: A male great white shark swimming near the surface of the Neptune Islands in South Australia, in 2005 (Auscape/UIG via Getty, FILE)

Ryan said one reason the researchers conducted the study was to help the sharks’ “general cognition”.

The study notes that shark bites, while rare, can have “devastating” effects on victims and first responders, hurting local businesses as tourism declines. Bites also negatively affect sharks, as they often lead to the implementation of mitigation measures for killer sharks.

MORE: A ‘little’ shark bites a girl on a North Carolina beach

Ryan added that researchers are studying some non-invasive mitigation efforts, such as changing the visual cues on surfboards — using LED backlighting to alter the shape of the surfboard’s silhouette from below — to reduce or prevent shark bites.

Great white sharks cannot distinguish between humans and seals: study originally published by abcnews.go.com

See also  Christmas speech by Queen Elizabeth II of the United Kingdom (video)

Leave a Reply

Your email address will not be published. Required fields are marked *