Remarkable rebound: Eastern Australian humpbacks exceed pre-whaling numbers
A preliminary report to Australia’s federal climate and environment department suggests the eastern Australian humpback whale population has rebounded to levels well beyond those recorded before commercial whaling nearly a century ago. Scientists estimate more than 50,000 eastern Australian humpbacks (Megaptera novaeangliae) inhabited the region in 2024, with potential counts reaching up to 60,000. This trend echoes a broader pattern of recovery among whale species since the whaling era, but stands out for its rapid and robust growth along Australia’s east coast.
How the estimate was derived
Researchers, led by veteran humpback specialist Wally Franklin—co-founder of The Oceania Project—compiled data from a 40-year dataset. They used observations and photographs submitted to the HappyWhale tracking catalogue by nearly 700 scientists, whale-watching operators, and citizen scientists. With more than 15,000 individual sightings analyzed, statisticians were able to model population size with greater confidence than ever before.
Dr. Franklin notes that pre-whaling populations were likely around 30,000, with only an estimated 150 surviving by the early 1960s after decades of intensive hunting. Since the 1963 International Whaling Commission moratorium on humpback whaling in the Southern Hemisphere, the eastern Australian humpbacks have shown a remarkable recovery, rising through the 1990s, into the 2000s, and now surpassing historical estimates.
Why this recovery is so striking
Unlike some other whale populations, which have plateaued or recovered more slowly, eastern Australian humpbacks appear to benefit from several favorable conditions. Australia’s long coastline provides a mosaic of habitats where mothers and calves can spend crucial early years in relative safety. Additionally, the species’ broad, seasonal migratory pattern—breeding in warm tropical waters during winter and feeding in Antarctic waters in summer—appears resilient in the face of changing marine conditions.
Adelaide Dedden, a marine scientist at the University of New South Wales who was not involved in the study, suggests that eastern humpbacks show notable adaptability. They breed in cold temperate waters in addition to tropical ones and may have shorter calving intervals (every two to three years) compared with southern right whales, which recalibrate on a four-year cycle. She also points out that the latter’s preference for sheltered bays makes them more susceptible to coastal disturbances than humpbacks.
What this means for the coast and conservation
The jump in numbers raises new questions about carrying capacity—the maximum population the environment can sustain. As the herd expands, interactions with boats and coastal communities are likely to increase. Experts emphasize responsible boating practices: maintain at least 100 meters distance from an adult whale and 300 meters when calves are present. Disturbance can force whales to mobilize energy reserves, potentially impacting their health and calf survival when disturbances are frequent along busy coastlines.
Public engagement remains a central part of the recovery story. Rather than approaching whales, observers are encouraged to let the whales come to them and to enjoy wildlife encounters on the whales’ terms. With ongoing monitoring and management, researchers hope to preserve this surge in population while ensuring safe, sustainable coexistence with people along Australia’s eastern seaboard.
Looking ahead
While the current trajectory is positive, scientists caution that growth may slow as carrying capacity is approached. Continued data collection—spurred by citizen science and professional collaboration—will be essential to understand long-term dynamics and to maintain the health of this iconic migratory population.
