Research undertaken by scientists from institutions across the US and Canada estimates that nearly 100 million sharks are killed every year. The research, to be published in the July edition of Marine Policy, highlights commercial fishing for shark fins as one of the primary drivers behind the exploitation.

Shark fins
Over ten thousand pieces of shark fins are dried on the rooftop of a factory building in Hong Kong 2 January, 2013. Local sales of the luxurious gourmet food have fallen in recent years due to its controversial nature, but activists demand a total shark fin ban in the city, labelled by some as the shark fin capital of the world. The fins were shipped from an unknown location and unloaded at a nearby pier to be dried on the rooftop

The research reveals the annual mortality estimate for 2000 was 100 million and for 2010 it was 97 million. It also indicates "a total range of possible values between 63 and 273 million sharks per year".

Boris Worm, affiliated to the Biology Department at the Dalhousie University in Halifax, Canada, said: "Our analysis shows that about one in 15 sharks gets killed by fisheries every year. With an increase demand for their fins, sharks are more vulnerable than ever before."

However, the research also cautions the scientific and conservation community that the data is not foolproof; sharks are sometimes killed while the fishermen are out at sea and their bodies, minus the fins, are thrown back into the water and not counted in official reports.

Demian Chapman, another of the scientists involved in the study and affiliated to the Institute for Ocean Conservation Science at the School of Marine and Atmospheric Sciences in New York's Stony Brook University, said: "There is a very large range and speaks of the quality of data, which is not great. Certainly 100 million is the median estimate and that's the best estimate there is."

"There is a really razor-thin level of mortality that sharks can experience before their population trajectory becomes negative - that is really what's been happening. They are not reproducing fast enough to keep up with the rate we are pulling them out of the ocean," Chapman explained.

Shark Fin Soup

One of the primary reasons for the severe exploitation of sharks is shark fin soup, a delicacy in certain parts of the world. In addition, they are also targeted for liver oil, meat and cartilage. The Chinese banned shark fin soup at government banquets, in June last year. However, growing demand among the civilian population is a worrying trend.

Conservation Battles

The Convention on International Trade in Endangered Species (CITES) is to meet in Thailand this month and talks on regulation in trade of five specific species of sharks - Oceanic Whitetip, Porbeagle and three types of hammerheads - are on the agenda. Also, the Pew Charitable Trust has urged delegates to the CITES meeting to "seize this opportunity to protect these top predators from extinction". At a previous meeting in 2010, efforts to curb shark hunting fell marginally short of the two-thirds majority required.

Bad PR for Sharks

Another major reason for sharks receiving little or no support from the internatinal community is the severity of media coverage, from around the world, relating to shark attacks. Reports, such as the recent one about a Great White Shark off the coast of New Zealand, do not help the animal's cause and neither does misinformed public perception that the animal is a danger to humans in the water. The truth - the University of Florida's International Shark Attack File lists only 80 attacks (seven fatal) in 2012.