Sightings Signal Potential Recovery of Whales Off Southern Africa
Recent sightings of blue whales and fin whales off Southern Africa’s Atlantic coast suggest that these marine mammals may be rebounding after being nearly wiped out by commercial whaling in the 20th century, according to a new study by University of Cape Town researchers. The findings, published on 6 Jul 2026, highlight increasing whale presence in the Benguela ecosystem.
Historical Context of Whaling Devastation
Scientists estimate that approximately 350,000 Antarctic blue whales (Balaenoptera musculus intermedia) and some 725,000 fin whales (B. physalus quoyi) were killed in the Atlantic during the industrial whaling era from 1913 to 1978. This relentless hunting drove both subspecies to near extinction in the region.
Study Findings in the Benguela Ecosystem
A research team led by Bridget James of the University of Cape Town set out to assess whether both subspecies are recovering in the Benguela ecosystem, a stretch of water between the west coasts of northern Angola, Namibia and South Africa. This area’s nutrient-rich upwelling produces abundant krill, a key food source for both whale subspecies.
Reported Sightings and Strandings
The team found that between 1964 and March 2025, there were 17 reports of blue whale sightings and one report of stranding in the region. They also recorded 76 fin whale sightings and six strandings. Blue whales were most often seen from late spring to summer (October-December) and autumn (March-April), while fin whales were observed year-round. Although the total number of sightings remains relatively low, 95% of them were recorded since 2012.
Implications for Population Recovery
James noted that the Benguela ecosystem serves as a migratory corridor between breeding and feeding grounds for the whales, and increased sightings are an expected indicator of population recovery. Current Antarctic blue whale populations are estimated at about 3% of pre-whaling numbers, while fin whale numbers have recovered to more than 30% of historical levels. James said that increases to at least 50% of pre-whaling abundance would suggest successful recovery for both subspecies. However, she cautioned that whales have relatively few offspring and long intervals between births, making their recovery times very slow.
Challenges Ahead and Expert Perspectives
As whale numbers increase, they face new challenges in an ocean that is now very different from whaling times. James noted that one blue whale had died off Namibia, possibly due to a ship strike, and that industrial noise from large vessels adds further pressure. Asha de Vos, a blue whale expert from Sri Lanka not affiliated with the study, told Mongabay that similar trends have been observed elsewhere following the end of commercial whaling, often consistent with gradual population recovery and reoccupation of historical habitat. She added that an increase in sightings could also reflect more whales traversing the region rather than an absolute recovery, and emphasized the need for continued long-term monitoring.
The findings provide promising evidence that warrants ongoing conservation efforts to support the recovery of these iconic marine mammals.