Whale shark survival threatened by over-fishing

Researchers at Shandong University at Weihai and Murdoch University in Western Australia have found distressing trends in the catching and trading of threatened whale sharks around the Chinese coast.

Results indicate that whale sharks are increasingly being targeted because of high demand for large shark fins and a rising appetite for shark meat in general.

“There is no targeted whale shark fishery in China at the moment, although with the high prices now being paid for shark fins this is likely to change,” said Brad Norman of Murdoch University’s Centre for Fish, Fisheries and Aquatic Ecosystems Research.

“While whale sharks are covered by law in China as a second-class national protected animal, catches are generally unmonitored and trade is uncontrolled, similar to other shark species.”

Norman and his collaborators surveyed more than 2,500 fishermen in 27 fishing harbours in eight coastal provinces. They also conducted field-based interviews in Puqi, Zhejiang province, known as the shark processing base of China.

“Fins are the most expensive shark product", according to Norman, although demand for other parts is also high: "liver oil, lips, cartilage, skin, brain, stomach and meat are now important commodities, supporting expanding consumption at the domestic level”, he said.

“Puqi has 20 local seafood restaurants that feature a ‘shark feast’ marketed on nutritional value, which is making the city a famous attraction for tourists. This means competition for large-sized sharks remains fierce.”

Fishery enforcement officials paid little attention to direct and incidental captures and often incorrectly informed fisherman that whale sharks were not a protected species. The research findings were preliminary but strongly indicated an emerging crisis for whale sharks in China, he said.

“Whale sharks are highly migratory though these migration patterns are poorly understood,” Norman said. “Limited tracking studies have shown they can travel thousands of kilometres [and] while they are protected in Australia, once they leave our waters, they are at risk of being hunted.”

* An interview with Brad Norman is available on the National Geographic site.