Recovery Milestone: Humpbacks Surpass Pre-Whaling Numbers
The eastern Australian humpback whale population has not only recovered; it appears to have exceeded the pre-whaling numbers that once defined the species along Australia’s east coast. A preliminary report to the federal Department of Climate Change, Energy, the Environment and Water estimates there were more than 50,000 eastern Australian humpbacks (Megaptera novaeangliae) in 2024, with some estimates reaching as high as 60,000. This marks a striking rebound from the brutal depletion caused by commercial whaling in the 19th and early 20th centuries.
Historical Context: From Brink to Breakthrough
Before large-scale whaling, humpbacks were reported in spectacular abundance along Australia’s coast. We know from historical records that ships navigated among dense pods in waterways like the Derwent River in Hobart, and coastal homeowners heard the constant songs of whales. The whaling era dramatically reduced numbers: scientists estimate the eastern Australian humpback population peaked at about 30,000 before whaling and dwindled to roughly 150 individuals by the early 1960s. After the International Whaling Commission banned humpback whaling in 1963, recovery slowly began, with eastern humpbacks reaching around 1,000 individuals in the subsequent decades and roughly 25,000 by 2015.
New Data and What It Means
The latest estimate comes from a 40-year dataset drawn from observations and photographs submitted to the HappyWhale tracking catalogue by nearly 700 researchers, tour operators, and citizen scientists. By 2024, the data set included more than 15,000 individual whales with repeated sightings, enabling statisticians to build robust models. Lead author Dr. Wally Franklin notes the number is “more than 50,000” and possibly up to 60,000, underscoring a recovery that far outpaces many other whale populations.
Why is the East Coast Recovery So Strong?
Experts point to several factors. Australia’s long coastline offers numerous habitats ideal for mothers and calves during the early life stages. In addition, population growth tends to outpace some other species due to less competition for food in certain seasons and regions. Adelaide Dedden, a marine scientist at the University of New South Wales, highlights that eastern humpbacks appear highly adaptable, with births occurring in cold temperate waters, not just the tropics. She also notes differences in reproductive rates: humpbacks can breed every two to three years, whereas southern right whales typically calve about every four years, which influences each species’ recovery trajectory.
Conservation and Human Interaction
As the population nears what scientists call carrying capacity, interactions with boats could increase. Dedden emphasizes respecting established approach distances: 100 meters for adults and 300 meters when calves are present. Disturbance from boats can quickly deplete a whale’s energy reserves as they swim away, potentially impacting their health and calf development if disturbances are frequent. The prevailing advice is to let whales approach on their terms and to enjoy responsible, passive viewing from a respectful distance.
Looking Ahead
While the rise is encouraging, scientists caution that continued monitoring is essential to confirm whether the growth will stabilize. The concept of carrying capacity suggests a natural ceiling, beyond which growth slows. Ongoing data collection, habitat protection, and responsible maritime practices will be key to sustaining this remarkable recovery for eastern Australian humpbacks as they migrate along the coast each year.
