QUEENSLAND, Australia (18 Jan 2005) -- THE hungry shark looks up at the silhouettes of the swimmers paddling idly on the water's surface. One swimmer is wearing a yellow swimsuit, the other black. Which one does the shark want to eat? Probably neither. But some scuba divers will tell you the one in the "yum-yum yellow" is for it. Whether the shark can distinguish colour or sees its watery world in shades of black and white is still in dispute. And that's what University of Queensland researcher Nathan Hart intends to find out. Dr Hart recently won $500,000 over five years under the Australian Research Council's coveted QEII fellowships scheme. He will look into the eyes of sharks, skates and rays - elasmobranchs - to discover which species have colour vision, why, and how their eyes are adapted to particular habitats. "After years of speculation, we have discovered that some elasmobranchs have multiple cone visual pigments and the potential for colour vision," he said. "This is of fundamental significance to the biology of these charismatic animals and their prey." That prey included people: Dr Hart, a biologist in UQ's vision, touch and hearing research centre, hoped his research would help reduce shark attacks. The findings could inform areas such as surfboard design and the colour of swimsuits and wetsuits to reduce the likelihood of shark attacks on people. But one of the most important spin-offs could be conservation - helping to reduce the millions of sharks killed by people each year. | | For example, long-line lures could be better designed to reduce shark bycatch in the fishing industry. "It would be very nice if we could find out what colours sharks don't like. Maybe they use colour for different things than we do," Dr Hart said. He said he was finishing a story begun 30 or 40 years ago, when the US Navy tried to find out why its downed pilots and sailors were getting eaten by sharks. At that stage they could not prove whether sharks had colour vision. "The fascinating thing about all those tests that the navy was doing was that some sharks were attracted to yellow and other sharks were repelled by yellow," Dr Hart said. "Whether that means they're attracted or repelled by bright things, depending on species, or whether there is a colour [connection], remains to be seen." For now he was keeping an open mind. He said he was yet to see evidence to support the theory that sharks see in colour. SOURCE - VOA |
