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Scientists are using elephant seals to gather crucial information about the Southern Ocean in areas they could never dream of going themselves.
Since 2006, scientists have been visiting Prydz Bay near Davis Station to capture seals that have just moulted.
They glue the sensor on their heads and information starts transmitting straight away.
"Elephant seals, because they come to the surface to breed, are perfect," said Clive McMahon, the Integrated Marine Observing System (IMOS) satellite tracking operations manager at the Sydney Institute of Marine Science.
"They'll go down, dive, collect great information, and then return to the surface, and that information will be transmitted by satellite almost in real time back to us in Australia."
Elephant seals dive almost continuously while at sea, gathering information including temperature and salinity wherever they travel and giving scientists new insights into remote and previously inaccessible locations.
The ABC was with a team of scientists when the first of the seals came in to Davis Station to moult a couple of weeks ago.
"The moult is really only just starting here at Davis Station. It's a little bit delayed here in the Antarctic," Dr McMahon said.
"We've just managed to capture an animal and attach one of our clever satellite trackers to it."
A bag was placed over the animal's head to help calm it, and vet Dr Esther Tarszisz anesthetised it.
"I come in and anaesthetised the seal. That's really the most important part, to get it in quickly so it's the least stress for the seal, and we want to make sure it doesn't move a long way down the beach towards the water or we'd have to probably stop," Dr Tarszisz said.
Sensor live immediately after operation
Glue was painted on the elephant seal's head and a sensor was attached. The whole operation took about 40 minutes.
Incredibly, the sensor was live immediately.
Soon, the elephant seal's journey was transmitting back to base in Hobart.
"We're really pleased with how it all went," Dr McMahon said.
"The seal was induced really quickly, he went to sleep really fast and we managed to get the instrument on.
"And we collected a length and a weight and some girth measurements and the seal is now happily recovering and snoozing on the beach.
"The anaesthetic does have an amnesic component to it, so it helps the animal forget."
The sensors measured temperature, depth and salinity as the seal swam and dived — sometimes to depths of more than 2 kilometres.
The data was beamed back to the IMOS in Hobart via satellite, giving scientists crucial information about ocean currents and where they are formed, as well as seals.
"It ends up at the Australian Ocean Data Network, which is a facility within the Integrated Marine Operating Systems program, and that data is available to the global community essentially in real time or within a day or two, so it is quite an incredible feat for a large program to make data freely available to be used in ocean modelling, animal studies and I guess just general oceanographic work," Dr McMahon said.
Seals with and without sensors compared
But do the seals mind having a sensor on their head?
"We've looked at whether the seals with sensors grow differently to animals that aren't carrying instruments — they don't," Dr McMahon said.
"We've looked at some of the behaviours of the animals and whether they scratch the instrument by rubbing their heads, and we've seen none of that."
The team at Davis Station put sensors on six elephant seals this summer season.
There are about 300 animals with the instruments on their heads swimming around the polar region.
Topics: animals, animal-behaviour, science-and-technology, oceans-and-reefs, research, antarctica
First posted