Recent research suggests there are more tigers left in the wild than there are great white sharks

Great white sharks may be more endangered than tigers, with only a few thousand left in the world's oceans, according to a leading marine biologist.

The grim assessment suggests that fishing and collisions with shipping vessels have taken a devastating toll on the ancient predators.

The World Conservation Union, which operates the red list of endangered species, lists great white sharks as vulnerable but has no official estimate of their global population. But a recent survey suggests that great whites have fallen below 3,500 individuals, the number of tigers conservationists believe are left in the wild.

A team led by Barbara Block, a marine biologist at Stanford University, used radio transmitters to track more than 150 great white sharks off the coast of southern California.

"The estimated total population of great white sharks in the world's oceans is actually less than the number of tigers," said Ronald O'Dor, a senior scientist at the Census of Marine Life, an international collaboration that is cataloguing marine life.

"We hear an awful lot about how endangered tigers are, but apparently great white sharks are pretty close to the same level. Some people say 'I don't care, they eat people,' but I think we have to give them a little space to live in," O'Dor told the American Association for the Advancement of Science meeting in San Diego yesterday.

"The Australians have now got a system where they put tags on great white sharks and they have receivers on the beaches so when a great white comes into the bay the receiver automatically makes a cell phone call and tells the guy in charge to close the beach. So we can co-exist with marine life," he added.

In 2007, marine biologists at Dalhousie University in Canada analysed records from fisheries and research vessels dating from the 1970s to 2005 and found evidence for a dramatic fall in shark populations. Tiger sharks and scalloped hammerheads had declined more than 97% since the mid-1980s, while numbers of smooth hammerheads and bull sharks fell 99% off the east coast of the US.