How to hide from sharks

Sharks are some of the best hunters in the animal kingdom — which is why it's surprising that they can't do one simple thing: see in colour.

Researchers at the University of Western Australia and the University of Queensland recently studied 17 species of sharks and found them all to be colour-blind. The sharks' retinas are able to distinguish only between light and dark shades.

This means that divers and surfers wearing light-coloured suits are at less risk of attack, because the sharks cannot see them as well.

"We may be able to use this information to help design surf craft and swimming attire that are less attractive or more repulsive to sharks and thus reduce attacks on people," says Prof. Nathan Hart, who wrote the team's report. "We might also be able to use it to design long-line fishing lures that are less attractive to sharks ... and reduce the huge numbers of sharks that are killed by catch each year."