[Editor’s Note: 81 female and calf pairs were counted by the Great Australian Bight Right Whale Study Centre during a single day in July.]
Researchers are using drones to study endangered southern right whales in their Great Australian Bight breeding grounds, capturing images from above of record numbers of mothers and calves this season.
The Great Australian Bight Right Whale Study Centre has counted 172 whales, including 81 female and calf pairs in one day in July, the largest numbers in the centre’s 26-year census.
Lead researcher Claire Charlton, from Western Australia’s Curtin University, said the record was encouraging after the centre’s lowest population count of 72 whales last year.
Further studies since the census have revealed 95 mother and calf pairs, taking the Australian population to almost 3000.
“Up to the early 1970s, there were no sightings of southern right whales, not only in Australia but around the world,” she said.
However, it would take decades before the whales, which return to feed on krill and plankton in sub-Antarctic waters in summer, are removed from the endangered list, Ms Charlton said.
Murdoch University researcher Fredrik Christiansen said the drones were equipped with rangefinders allowing them to measure more than 170 individual animals to assess body size and health of mothers and calves over the three-month season.
The Murdoch project, partly funded by WWF Australia, aims to study one of the whales, which are among of the world’s fastest growing mammals, capable of growing from 5m to 8m during their three months in The Bight.
However, the mothers can lose 30 tonnes in weight during calving season as a result of their not eating and feeding their young.
“This project will benefit the conservation of southern right whales by teaching us more about their health and reproduction, which will have a direct influence on population growth and status,” Dr Christiansen said.
It would also provide a benchmark from which to study the effects of oil drilling activity, climate change and shipping on the whales.
The Bight is currently hosting oil and gas companies Chevron and BP, which are looking to develop an oilfield.
BP recently lodging its environmental plan to the National Offshore Petroleum Safety and Environmental Management Authority, but conservationists have raised concerns about the effects of exploration and drilling on the whales.
The whale centre, near the South Australian town of Nullarbor, 1200km west of Adelaide, had in recent months attracted an estimated 200 visitors a day, Dr Christiansen said.