Scientists have detected singing by blue whales in the Antarctic from almost 750-kilometres away.
The researchers, part of a six week Australia-New Zealand Antarctic ecosystem voyage to the Southern Ocean returned to Wellington, New Zealand, today.
Brian Miller, Australian Antarctic Division Lead acoustician, says directional sonar buoys were used to listen for the low rumbling of blue whales, the world’s largest creature at 30-metres long and weighing 190 tonnes, and guide the ship to them.
“It is really exciting to be able to study these whales in the vast Southern Ocean and hear their calls over 750km away,” Dr Miller says. “During the voyage we were able to record more than 40,000 calls over 520 hours.”
Listen to the song of a Blue Whale below.
The scientists were staggered to see more than 80 of the rare whales in a relatively small area.
They photo-identified 58 individual blue whales during the voyage. These images will help estimate the population size, rate of recovery and movements of the endangered Antarctic blue whales.
Here’s footage from the voyage, showing blue whales in the icy seas:
Mike Double, Australian Antarctic division voyage science leader, said it is only possible to study this endangered species efficiently using the acoustic technology developed by the Australian Antarctic Division.
“Our ability to find these whales and the multidisciplinary nature of the voyage also allowed us to investigate the whales’ habitat,” he said.
“Using echosounders we were able to map, characterise and monitor the krill in the vicinity of the blue whale and found the swarms were denser than those found anywhere else.
“Remarkably, using new advanced echosounders, we were able to track individual krill for the first time allowing an examination of the changing internal structure of the krill swarms. Additionally oceanographic data was gathered which will show the productivity of the waters.”
The voyage is a collaboration between Antarctica New Zealand, the New Zealand National Institute of Water and Atmospheric Research (NIWA) and the Australian Antarctic Division.
The non-lethal whale research conducted on this voyage aimed to investigate key questions identified by the International Whaling Commission’s Southern Ocean Research Partnership (SORP).
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