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Written by DIVE Magazine Thursday, 21 February 2013 11:15
A project tagging oceanic whitecap sharks found they wander over vast tracts of ocean.
A research project in the Bahamas tagged 11 oceanic whitecaps off Cat Island in 2011 and results published this week in the journal PLOS ONE found that some of the sharks roamed nearly 2,000 kilometres from the spot where they were caught, but all individuals returned to the Bahamas within a few months.
'While the oceanic whitetip shark is one of the most severely overexploited shark species, it is also among the least studied because it lives much of its life far from land in the open ocean,' said Lucy Howey-Jordan, scientific liaison for Microwave Telemetry, Inc. and lead author. 'Before this study and our ongoing research, very few of these sharks had been fitted with satellite tags, and the data we obtained will help establish new conservation measures.'
All the tags, except one, reported data. Of the eight tagged oceanic whitetip sharks tracked for more than 31 days, three stayed within or very near the Bahamas for their entire tracking period. The other five sharks, after an approximate 30-day period of residency within 500 kilometres of the tagging area, made long-distance trips, with one traveling as far as Bermuda.
The fact that all these tagged mature female sharks returned to the Bahamas provides the first evidence of return-migration in this species. The sharks, normally found near the ocean's surface, made regular dives of approximately 1,000 metres, possibly related to feeding.
The oceanic whitetip is one of the species of sharks that next month is being considered for a full trade ban under CITES. This protection is essential for species which cross international boundaries such as the oceanic whitetip.