Tagging expert Dr Virginia Andrews-Goff with a blue whale skin sample she collected. Picture: SAM ROSEWARNE
LIKE the whalers of old, Tasmanian marine biologist Virginia Andrews-Goff stood at the bow of a small boat in a wild sea, aimed her weapon at the body of a blue whale and fired.
Her direct hit implanted a satellite tracking device that would astound researchers with its revelations.
It was one of the high points in a modern voyage of discovery this summer that involved scientists from the Australian Antarctic Division and four other nations.
The team used acoustic buoys to track down more than 80 rare blue whales in the far Southern Ocean, getting close enough to take precious skin samples from 23 of them and attach satellite tags to two.
The research team in action
Expeditioners also took close-up photos of 57 whales to establish their identities and distinguishing marks.
One of the tagging experts, Dr Andrews-Goff said it was intimidating being so close to the world's largest animals some of them three times longer than a bus surging through the ocean at great speed.
"I was the size of an ant next to one of those giants," she said.
"I was deliriously happy when I managed to attach a tag." Since then, the satellite trackers have shown the whales travelling up to 100km a day.
"I was surprised at the distance and speed they swam," Dr Andrews-Goff said.
DNA analysis of the small skin samples is providing a wealth of information about the endangered species.
Australian Antarctic Division chief scientist Nick Gales said the voyage proved it was not necessary to kill whales for research, as Japanese hunters suggest.
Dr Gales said tracking and analysing living whales was far more productive.
"There isn't a scientific reason to go and kill a whale in the Southern Ocean," he said.
The Australian Antarctic Division chartered a large New Zealand freezer-trawler called Amaltal Explorer for the research project, which used sonar technology developed to track submarines in the Cold War and refined over three decades.
Marine mammal acoustic expert Brian Miller said blue whales sang songs in perfect pitch at very low frequencies, which could be detected hundreds of kilometres away.
Acoustic buoys launched from the trawler tracked the songs and provided details about the whales' locations.
In 626 hours of recording, Dr Miller and his colleagues detected more than 26,000 calls.
They monitored the sounds on board the trawler and when they got close, set more buoys in a triangle to narrow down the focus of the search. When the whales were spotted by on-board observers, taggers boarded small boats and approached the leviathans as they swam by.
The work went on in freezing conditions in all weather, often close to the edge of the Antarctic ice shelf.
Last year the scientists conducted a trial voyage to the west of Bass Strait and in November they practised tagging humpback whales for several weeks off south-east Tasmania.
The Antarctic blue whale was hunted almost to extinction by industrial-scale whaling in the early years of last century.
Its numbers crashed from an estimated 200,000 in the Southern Ocean to almost none by 1966, when hunting of the species was banned by the International Whaling Commission.
The population has recovered very slowly compared with other whale species and scientists estimate only about 2000 Antarctic blue whales exist in the Southern Ocean today.
philip.heyward@news.com.au
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