Don’t worry about yum-yum yellow, sharks are colour-blind

SYDNEY: The US Navy did tests on colours other than yellow for the life jackets military pilots wear in case they have to eject and splash down into the ocean.

They found that sharks were less likely to be attracted to red or black than what one wag called “yum-yum yellow”.

However, those 1970s tests were a waste of time, researchers in Australia have said, because sharks – along with whales, dolphins and seals – are colour-blind.

Nathan Hart, a neuro-ecologist at Perth’s University of Western Australia, said it was likely that the ancestors of sharks could see in colour but evolution had lost them this facility.

Hart’s research, published in The Royal Society’s Biology Letters, builds on that done by Susan Theiss, a colleague at Brisbane’s University of Queensland. Their work could lead to better designed fishing equipment, which use glows to attract fish, that would reduce the number of sharks hooked inadvertently.

So if colour does not come into it, what ought people in the water do to make themselves less attractive to sharks? According to Hart: “There are two ways to tackle this one: stand out and look like something unpleasant, or hide against the background.”

For life jackets, though, those most easily seen from above would be best. There is not a lot of utility in being hidden from those out looking for you. – Sapa-dpa