Bringing back southern right whales from extinction

Bringing back southern right whales from the brink of extinction

There aren’t many of these giants of the sea left.

As the early morning sun cast a warm, golden glow over the eastern coastline of Australia, a sense of anticipation filled the air. Families with binoculars and cameras, couples wrapped in warm blankets, and enthusiastic marine enthusiasts have all come together, drawn by the promise of nature’s grand show. Excited onlookers gather along the rugged shores, perched on cliffs, or nestled in the comfort of beachfront cafes, all sharing one common purpose: to witness the awe-inspiring spectacle of southern right whales (Eubalaena australis) on their annual journey.

Suddenly spectacular plumes of misty spray erupt from the surface. Each blow is a beacon, a signal that the giants of the sea are drawing near. Excitement ripples through the gathering as the blows grow closer and more frequent.

The whales, moving in a slow and purposeful procession, seem to acknowledge their captivated audience, offering glimpses of their mighty tails and elegant dorsal fins as they glide by.  And as the last glimpse of a fluke disappears beneath the surface, the spectators remain, silently paying tribute to the enduring beauty of the natural world and wishing them good luck.

For centuries, these marine mammals have woven themselves into the fabric of coastal communities in various parts of the world.

Primarily found in the southern hemisphere’s temperate waters, these whales are characterised by their large, robust bodies, often up to 15 meters long and weighing between 40 to 80 tonnes, making them one of the largest whale species on the planet. Their striking appearance features dark, nearly black skin adorned with patches of white callosities, which serve as unique identifiers for individual whales. They are filter feeders – baleen plates in their mouths strain from the water small planktonic organisms like krill and small fish. Their feeding grounds are primarily in polar or subpolar regions, while they migrate to warmer coastal waters for breeding and calving.

Their cultural significance also extends far beyond their ecological role and scientific interest. For centuries, these marine mammals have woven themselves into the fabric of coastal communities in various parts of the world. In many Indigenous cultures, southern right whales are revered, often regarded as spiritual symbols of wisdom, strength, and harmony with the natural world. Featured prominently in Indigenous oral traditions, they are sometimes considered divine messengers or protectors of the sea. Their enigmatic nature and awe-inspiring size have led to beliefs that they possess supernatural powers or embody the souls of ancestors. Today, they continue to inspire artists, writers, and musicians.

Yet, the southern right whale bears witness to a tumultuous history that spans centuries. Ruthlessly targeted for commercial hunting from 1790 to 1980, they faced a perilous existence. The global death toll from this relentless hunt exceeded 150,000 individuals, with the carnage being particularly severe in the waters off New Zealand and southeastern Australia. More than 58,000 Southern Right Whales died near New Zealand; 19,000 off Australia.

The road to recovery for these giants has been slow and fraught with obstacles, particularly when compared to species like the humpback whale (Megaptera novaeangliae), which have experienced a swifter resurgence.

Sadly, the eastern population is now estimated to comprise fewer than 300 individuals.

Cetaceans, often regarded as flagship species and ecological indicators, face mounting challenges in the form of climate change, fisheries, industrial development, consumption, and pollution.

Australia plays a vital role in the conservation efforts for southern right whales, housing two genetically distinct populations: a western Australian group that calve in South Australian and WA waters, and an eastern Australian population with breeding ranges extending from Victoria to southern Queensland. In particular, southern right whales in the eastern Australian population are exposed to  anthropogenic threats, highlighting the urgent need for conservation efforts throughout their range, including breeding and foraging areas.

But researchers announced only a little over a month ago they had tracked the complete migration cycle of an Australian southern right whale in detail.

Sadly, the eastern population is now estimated to comprise fewer than 300 individuals, including just 68 breeding females, while the western population boasts over 2,500 individuals.

“That’s not many when you consider there was probably at least 25,000 prior to whaling in the 1800s,” says Dr. Stephen Burnell, Chief Investigator and pioneer of the long-term Southern Right Whale research project at Head of Bight.

The creatures possess a unique population structure driven by their distinct preferences for winter calving and summer foraging. Their choices are guided by a remarkable combination of strong site fidelity and ‘cultural memory,’ although they are capable of sudden location shifts, challenging our understanding of their behaviour.

They’re still nowhere near the numbers they were pre-whaling, but they’re recovering.

Dr. Stephen Burnell

The south-eastern coast of Australia remains crucial for the survival of the Eastern population, with Logans Beach near Warrnambool in Victoria standing as the sole established calving area in the region. Remarkably, this site has retained its ‘cultural memory’ for southern right whales, likely due to the survival of females familiar with the location during the brutal whaling era.

Yet, despite the dark chapters of their past, the story of southern right whales is one of resilience and hope. The Australian Southern Right Whale Study commenced its species survey in 1991, and in the years that have followed, scientists report a remarkable recovery of the population from the brink of extinction: both populations are growing at a rate of approximately 5% per annum.

“They’re recovering well […] they’re still nowhere near the numbers they were pre-whaling, but they’re recovering,” says Burnell. “It’s on a good track, they’re a threatened species, they are recovering. It’s encouraging to see them recover but it’s going to be some time before they’re fully back in their original habitats.”

Dr. Claire Charlton from Curtin University, who has been collaborating on the population study alongside Burnell, revealed that primary calving sites, such as those at the head of the Australian Bight, are experiencing increased occupancy during years of heightened abundance.

Charlton noted, “more and more whales [are] appearing in small and emerging calving grounds inside and outside of protected areas across the Australian marine park network.”

Photograph of two baleen whales southern right whales underwater
A southern right whale calf and its mother. Credit: By Wildestanimal / Moment / Getty Images.

“The whales are actually choosing to select alternative calving habitat,” which include locations like Fowlers Bay, Encounter Bay, Portland in Victoria, and Geographe Bay in Western Australia – all near former whaling stations.

According to Burnell, years ago whales were observed calving approximately every three years. However, he pointed out that now the average calving interval falls somewhere between four and five years, signifying a discernible deceleration in population recovery. Charlton believes the abundance of these whales in Australia may provide insights into what’s transpiring in their foraging habitats.

The Southern Right Whale Conservation Management Plan is set out by the Australian government.  It necessitates addressing significant knowledge gaps in our understanding of the species’ needs, migratory patterns, and impacts of climate change.

Southern right whales serve as a sentinel species for monitoring climate change in the southern hemisphere, and their ability to reproduce is closely tied to the environmental conditions in their offshore feeding areas.

The Ultramarine project – focussing on research and innovation in our marine environments – is supported by Minderoo Foundation.

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