A WHALE expert has slammed a West Australian man as “daft” for sitting on a whale carcass as it was being circled by massive sharks.

Harrison Williams, of Mindarie, near Perth, was photographed sitting shirtless on the dead whale about three nautical miles northeast of Rottnest Island as at least three sharks were feeding on it.

Mr Williams, a lover of extreme sports, jumped off a nearby boat and climbed onto the rotting mammal, which was providing a welcome meal for nearby tiger sharks and at least one great white. Several other men were watching on from the boat.

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Mr Williams told the Daily Mail that “the whale looked in distress and I tried to help it”, but Sydney-based whale expert Will Jones said the risk he took by climbing onto the whale was not worth the “legend photograph” he was obviously after.

“A carcass will be biodegraded in big chunks by our great white friends,” Mr Jones told news.com.au.

“Most sharks are efficient, or lazy is another way to put it, with what they eat. One of their jobs is to clean up (these carcasses). They will make massive-sized bites out of it, just huge. They gorge on these things. It’s fat and it’s a great energy source.”

Mr Jones said sharks were after the whale meat, but Mr Williams had left himself open to being attacked by mistake.

“It’s a really, really dumb idea, which is obvious to say, however it would a very interesting experience. He could probably float right next to the damn thing and be completely ignored because it’s the high-energy source that they’re after,” Mr Jones said.

“No one’s been daft enough to do it before, and hopefully they won’t again.”

Mr Jones said swimmers were legally obliged to keep a wide berth from whales, dead or alive.