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London, Oct. 7: A great white shark named Nicole has completed the first known ocean crossing by a lone shark over a record-breaking distance of over 12,400 miles.
The epic swim means that the endangered sharks ? the largest predatory fish in the ocean ? could be in more danger from fishing than had been thought. Scientists watched in awe as the female ? named after Australian actor and white shark lover Nicole Kidman (picture on top) ? made her ocean crossing twice, after she was tagged with a tracking device off South Africa.
In addition to travelling farther than any other known shark, Nicole completed the return trip to Australia in just under nine months. It is the fastest known back-and-forth swim. Nicole ? originally designated shark P12 ? also provides the first physical link between two of the most important and widely separated populations of great white sharks.
Her travels have astounded researchers and challenged long-held notions about these awesome predators, the Wildlife Conservation Society based in Bronx Zoo and other organisations reported today in the journal Science. “This is one of the most significant discoveries about white shark ecology and suggests we might have to rewrite the life history of this powerful fish,” said Ramon Bonfil, the lead author.
“Nicole has shown us that separate populations of great white sharks may be more directly connected than previously thought.” That means “wide-ranging white sharks, which are nationally protected in places such as South Africa and Australia, are much more vulnerable to human fishing in the open oceans than we previously thought”.
There is still much to learn about why and how sharks find their way through such vast distances, and how populations are related, Bonfil added.
Nicole’s story began in November 2003, when Bonfil and his colleagues from the Marine and Coastal Management Department of South Africa and the White Shark Trust attached a satellite tag to her dorsal fin. The tags record data on time, temperature, water depth and light levels.
On a pre-recorded date, the tag detaches from the shark and floats to the surface, where it transmits its data to a researcher’s computer via satellite.