Mongabay.com – August 11, 2008

One area of the world that has been impossible to monitor is the sea-ice of Antarctica's Southern Ocean. The inability of satellites to 'see' through the ice and the difficulty for ships in exploring them has made these regions a blank zone for data collection related to climate change research. However group of researchers has found a way around these challenges. Ingeniously, they have attached oceanographic sensors to elephant seals that dive deep and feed among the sea ice.

The invaluable seals "provided a 30-fold increase in hydrographic profiles from the sea-ice zone," the researchers write. In addition they allow "the major fronts to be mapped south of 60°S and sea-ice formation rates to be inferred from changes in upper ocean salinity." The seals have the ability to dive 1500 meters and stay underwater for up to two hours. To study the data gaps, scientists tagged 58 elephant seals on four Antarctic islands. The seals swim distances of 35-65 kilometers (21-40 miles) in search of food, all the while taking important measurements of ocean salinity, temperature, and in some places sea-ice formation. Combing the conventional data provided by ships and satellites with the seal-collected information provide a far greater view of the Southern Ocean. "Elephant seals fill a ‘blind spot’ in our sampling coverage," the authors write, "enabling the establishment of a truly global ocean-observing system." The researchers suggest that the same usage of elephant seals for climate data should be extended to other Antarctic predators, including other seal species.

Read Full Article: Elephant seals go where no one has gone before: using seals for climate change research