Blue whales and fin whales, driven to the brink of extinction by 20th-century industrial whaling, are slowly returning to the southeast Atlantic, according to new research led by the University of Cape Town (UCT).
The study, published in the African Journal of Marine Science, compiled more than 60 years of verified sightings and strandings along the coasts of Namibia and South Africa — the Benguela upwelling ecosystem, a nutrient-rich corridor where whales historically fed and raised young.
Between 1913 and 1978, an estimated 350,000 Antarctic blue whales and some 725,000-750,000 fin whales were killed in southern waters. Today, Antarctic blue whales remain critically endangered, with populations estimated at just 3% of pre-whaling numbers but growing 5-8% per year; fin whales, listed as vulnerable, have recovered to more than 30% of historical levels and are growing 4-5% annually.
In the region, researchers recorded 12 blue whale sightings, one stranding and five additional published records, plus 76 fin whale sightings and six strandings between 1964 and March 2025 — with the vast majority of sightings occurring since 2012.
"Our results provide important evidence that these giants of the ocean are slowly recovering from the devastating impact of 20th century commercial whaling, which pushed them to the brink of extinction," said lead author Dr Bridget James. "Sightings remain rare, but they are becoming more frequent than in previous decades."
Co-author Dr Simon Elwen cautioned that the increase partly reflects growing observation effort, including marine wildlife observers aboard seismic survey vessels. The researchers warn that recovery is far from complete: large whales still face ship strikes, entanglement in fishing gear, underwater noise, pollution and climate-driven shifts in ocean ecosystems.
The authors recommend expanding passive acoustic monitoring, increasing trained observer coverage and incorporating whale distribution data into marine spatial planning to protect the slow but encouraging recovery.
Sources
- phys.orgPhys.org: After commercial whaling nearly erased them, blue and fin whales are slowly reclaiming the southeast Atlantic
- timesofindia.indiatimes.comTimes of India: Commercial whaling killed 350,000 blue whales and 725,000 fin whales — more than 40 years later, the giants are slowly returning to the southeast Atlantic
- news.uct.ac.zaUniversity of Cape Town: Sightings of blue and fin whales increase in South-East Atlantic
- news.mongabay.comMongabay: Sightings off Southern Africa suggest blue and fin whales may be rebounding
