Thursday, March 12, 2009

Great White Shark Sets World Diving Record

Tagged off Stewart Island, a great white shark has set a world diving record as it crossed the Tasman Sea to the Great Barrier Reef.

Three four-metre-plus great whites tagged off the Chathams have also surfaced in Tonga for a midwinter feast of humpback whale calves.

News of the sharks migrating to the tropics surprised Malcolm Francis, of the National Institute of Water and Atmospheric Research in Wellington.

"We used to think great white sharks were shallow-water coastal species that lived in cold areas, where there were lots of seals to eat," he said.

"Now we have changed our impression of what they do."

Niwa and the Conservation Department have been attaching satellite tags to great whites, to measure position, depth and water temperature. After several months, the tags pop off and float to the surface, where the data is transmitted to a satellite.

Dr Francis said that this year two Stewart Island whites had gone 4000 kilometres to Queensland's Great Barrier. Surprisingly, they go in a straight line.

"They seem to know where they are going," he said, noting that they moved through the water at between 4kmh and 5kmh, or an impressive 120km a day.

Up to 70 per cent of the time they are near the surface but this winter one of the whites dived. "We've got what we think is a world record of 1000 metres for a white shark."

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