The world's rising demand for shark fins is killing as many as 73 million sharks a year, according to a new study. The figure is three times higher than the official catch number reported to the United Nations and raises concern that the trade is having a devastating impact on shark species worldwide.
The findings are the first estimates based on real data of the number of sharks harvested for fins. "The shark fin trade is notoriously secretive," said lead author Shelley Clarke, an American fisheries scientist based in Hong Kong and Japan.
The research team calculated the number of sharks represented in the fin trade using a unique statistical model and data from Hong Kong traders. After converting the figures to shark weight, they concluded the total is three to four times higher than shark catch figures reported to the UN Food and Agricultural Organization. The study was published in this month's edition of "Ecology Letters."
The findings come amid growing concern about the recent growth of the shark finning trade. Sharks are vulnerable animals and their slow growth, late maturity and small number of offspring make them especially susceptible to overexploitation, and the species is slow to recover once depleted.
Furthermore, because most sharks are top ocean predators, over-fishing of sharks is likely to cause disruption to prey populations and an overall imbalance in marine ecosystems.
Sharks are targeted directly for their fins, meat and liver oil, but the value of shark fins is often many times greater that of shark meat. To meet the demand for fins, fisherman frequently catch sharks, slice off the fins and discard the body at sea.
The fins are primarily exported to China for use in shark fin soup, which can command prices in excess of $100 a bowl. Demand for the delicacy has increased as the Chinese middle class has grown, even as reported global landings of sharks have remained static or declined.
The study does come amid a bit of good news for sharks. Last week the European Parliament voted to tighten the EU's shark finning regulations, which allow fishermen to land fins and carcasses separately.
The rules, intended to prevent shark carcasses being dumped at sea, mandate that the weight of fins as a proportion of the total catch not exceed 5 percent. The EU Fisheries Committee had called for the ratio to be increased to 6.5 percent, but the parliament rejected that recommendation in favor of decreasing the ratio to 2 percent.