Elephant Seals: Data Collectors for Polar Oceans
Most of us turn to the weather channel, or the app on our phones to find out the forecast for the week, but where do these predictions stem from? Many of these forecasts are made possible by the analyses of decades of past climate data. From temperatures, to the amount of rainfall, to wind patterns, climate scientists and weather forecasters use this data to deliver insight to future weather predictions.
Understanding climate and weather systems in polar regions also plays a part in predicting these patterns. However, data collection in these extreme temperature regions is difficult and expensive as frozen seas prevent accessible channels for ships or buoys to collect data especially during long winters.
So how have scientists and marine biologists been able to collect this polar data? With the help of elephant seals, of course.
Elephant seals spend 90 per cent of their lives at sea, travelling up to 4000km on months-long feeding trips. They dive about 60 times a day, reaching depths of up to 2000 meters, serving as a perfect vessel for polar data collection.
Although the idea of using animals to collect data had been around for some time, Professor Mike Fedak, and his colleagues at NERC's Sea Mammal Research Unit persuaded the scientific community to take it seriously. 'We wanted to know more about the places the animals were visiting,' he explains. 'We'd ask the oceanographers "what's the ocean like here?" but they didn't know. NERC was using Autosub [a robot submarine] to explore under the ice, and we thought "we've got our own Autosub - the elephant seal!"'
Researchers have fastened special tags and sensors onto the heads of elephant seals in the Southern Ocean in order to collect temperature, pressure, and salinity measurements. The tags transmit a stored profile to a satellite with the animals hit surface to breathe.
Scientists are recruiting other species including Weddell seals, hooded seals and ring seals. 'We choose animals and program the tags to tailor them to where the oceanographers want to get data and to suit the behaviour of a particular species,' says Fedak. 'The beauty of it is that it's a partnership between oceanographers and biologists. It took a while for the oceanographers to accept it, but now they've really embraced it. It's so cost-effective compared to using ships.'
Marine animals — including seals, turtles and diving birds — have now provided over 1.4 million temperature profiles. Over 300,000 of these also measured salinity — crucial for a full understanding of ocean processes.
The collected profiles are made freely available every day via the World Meteorological Office.
For more information, check out Planet Earth Online.
Elephant seal image via Shutterstock.