Elephant seals join fight against climate change

By Michael Perry

SYDNEY (Reuters) - Elephant seals swimming under Antarctic ice and fitted with special sensors are providing scientists with crucial data on ice formation, ocean currents and climate change, a study released on Tuesday said.

The seals swimming under winter sea ice have overcome a "blind-spot" for scientists by allowing them to calculate how fast sea ice forms during winter.

Sea ice reflects sunlight back into space, so less sea ice means more energy is absorbed by the earth, causing more warming.

"They have made it possible for us to observe large areas of the ocean under the sea ice in winter for the first time," said co-author Steve Rintoul from Australia's Commonwealth Scientific and Industrial Research Organisation (CSIRO).

Conventional oceanographic monitoring from ships, satellites and drifting buoys, cannot provide observations under sea ice.

"Until now, our ability to represent the high-latitude oceans and sea ice in oceanographic and climate models has suffered as a result," said Rintoul, who also works with the Antarctic Climate and Ecosystems Cooperative Research Centre in Hobart.

The elephant seals have provided scientists with a 30-fold increase in data recorded in parts of the Southern Ocean, said the study by a team of French, Australian, U.S. and British scientists and published in the Proceedings of the National Academy of Sciences.

Between 2004 and 2005, the seals swam up to 65 kilometres a day, supplying scientists with 16,500 ice profiles. The seals dived to a depth of more than 500 metres on average and to a maximum depth of nearly 2 km.