Researchers use whale photo archive to help protect important whelping site in WA | Whales
Researchers are combing through thousands of photos of whales to help protect a calving site off Australia’s west coast that has been badly damaged by the whaling industry.
Researchers believe Geographe Bay in south-west Western Australia is an important calving ground in need of environmental protection and are using a 30-year-old archive of images to determine how many southern right whales have visited the area over time.
Southern right whales migrate annually from Antarctica to breed and give birth in Australian coastal waters.
They “come as far as the coast and give birth within 500 meters or 1 km of the coast,” said Chandra Salgado Kent, associate professor at Edith Cowan University and lead researcher on the project. She said mothers can have calves every three years on average.
The number of southern right whales was decimated in the 19th century by commercial whaling. The practice was banned in the 1970s and since then Australian populations have increased to around 3,400 individuals, but the species is still listed as endangered.
“No one knows exactly how many there were [prior to commercial whaling]but … estimates are that there would have been several thousand or tens of thousands of animals,” Salgado Kent said.
“They are believed to live at least to around 50 years, or possibly longer.”
The photographic archive of 3,000 images includes photos taken by scientists and volunteers. Many images were provided by Chris Burton of Western Whale Research, as well as local whale watching companies such as Naturaliste Charters.
Researchers can identify individual southern right whales by distinctive white markings on their heads called calluses. “In general, these characteristics are quite stable over the long term,” said Salgado Kent.
Salgado Kent said it was likely that Geographe Bay and Flinders Bay – around 100km further south – were historically significant calving sites.
“Are they expanding their breeding range and reinhabiting their old breeding grounds and historic calving grounds? It seems like the data points to that,” she said. “It is certain that Geographe Bay is now used consistently by mothers and calves, and more and more.”
To date, preliminary results of the study have identified 234 individuals in the southwestern region of Australia, including Geographe and Flinders Bays.
“It will inform the Commonwealth Conservation Management and Recovery Plan for Endangered Southern Right Whales, which is currently being reviewed and updated,” Salgado Kent said.
“This recovery plan essentially sets goals to see southern right whales recover in the future. Some of the goals include, for example, the ability to know exactly where these important areas are and to be able to take the right management actions.
The team also plans to research how breeding and calving grounds along the WA coast are connected, by matching photos of individual whales in different locations.