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Researchers study southern right whale nursery off WA coast as population recovery stalls
Each winter, southern right whales arrive on Western Australia's southern coast to birth their young.
In a remarkable natural habit, the mothers return to their place of birth to deliver their calves.
It offers scientists a chance to study the species' breeding habits as they travel to the crystal clear bay at Point Ann, on the edge of the Fitzgerald National Park, 520 kilometres south-east of Perth.
The study is key to understanding why the population has not bounced back like other species of whales since the end of commercial whaling in the 1970s.
University of WA researcher Maxl Fabry said there were still very few southern right whales "compared to what there used to be and what there should be".
The latest strategy for the research is to use drones and aircraft to help find answers.
Mr Fabry and Katy Fannei run this leg of the project, each year surveying a 450km section of coast from Albany to the national park.
Each year, they spot 30-70 mother and calf breeding pairs.
"Unlike humpbacks, which have recovered from whaling to quite significant extent, southern right whales are still struggling to establish their pre-whaling population," Mr Fabry said.
"Studies have shown that in the last 10 years, southern right whales are calving less and less, from every three years to every five years."
The group hopes keeping records of mother and calf pairs along the coast will aid understanding of these developments.
Photos and video will be added to international catalogues and shared with researchers across the world who study the species only found in the southern hemisphere.
"We can put together a much more comprehensive idea of what southern right whales are doing, how they're covering and what the health of the population is," Mr Fabry said.
"Southern right calving rates and their body conditions are really just a message in a bottle from the south coast, Antarctic waters and offshore waters.
"It could be a lack of prey availability, it could be anthropogenic impacts, it could be all manner of things, both human-made and natural processes."
A study by the Institute for Marine and Antarctic Science (IMAS), the University of Tasmania and the Australian Antarctic Division found their population recovery seems to have recently stalled at a level far below pre-whaling.
Researchers questioned whether it might be the "end of an era for southern right whale recovery".
There are estimated to be about 2,000-3,500 southern right whales in the Australian population, but that is a long way off the estimated pre-whaling numbers of 70,000-160,000.
Comparatively, there are an estimated 60,000 humpbacks in Australia's east and west populations.
Point Ann is one of three large aggregation areas for the whales in Australia.
Establishing long-term data sets to better understand the animals' recovery has proven difficult because the breeding patterns for each whale are not annual, making tracking numbers challenging.
In 2021, the group spotted 70 mother and calf pairs.
That dipped to 30 in 2023 and 60 last year.
"There is no clear pattern as to whether they're increasing or declining, it's very fluctuating," Ms Fannei said.
"They give birth every three to five years.
"That's elevating in recent years … individuals don't visit the coast every year."
Ms Fannei and Mr Fabry said the project relied on volunteers and the support of local business to continue its work.
"For long-term studies, having local support is so important — we need to know in the next three or five years [whether] we can keep doing this," Ms Fennai said.
