Southern Africa: Sightings of Blue and Fin Whales Increase in South-East Atlantic

Research led by the University of Cape Town's (UCT) Centre for Statistics in Ecology, Environment and Conservation, revealed a recent increase in sightings of the world's two largest whale species in the southeastern Atlantic.

The research findings were published in the African Journal of Marine Science and compiled more than 60 years of confirmed sightings and strandings from Namibia and South Africa's West Coast. The study focused on Antarctic blue whales and fin whales, both heavily targeted during the industrial whaling era.

"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 from the Centre for Statistics in Ecology, Environment and Conservation. "Sightings remain rare, but they are becoming more frequent than in previous decades, and with sustained protection there is reason to believe this recovery can continue."

It's believed that between 1913 and 1978, an estimated 350 000 blue whales and 750 000 fin whales were killed - causing dramatic global population declines. Today, Antarctic blue whales are still listed as critically endangered by the International Union for the Conservation of Nature Red List. Their population is currently estimated at around 3% of the pre-whaling numbers - increasing slowly at about 5-8% per year. Fin whales on the other hand are classified as vulnerable, with populations thought to have recovered to more than 30% of historical levels and growing at about 4-5% annually.

"Historic whaling data suggests that the southeast Atlantic may once have been an important nursery area for both blue and fin whales."

Despite these signs of improvement, both species remain difficult to study as they roam vast distances and spend much of their lives in remote Antarctic waters. Data from migration routes and potential breeding grounds, including the southeastern Atlantic, has been particularly limited.

"Historic whaling data suggests that the southeast Atlantic may once have been an important nursery area for both blue and fin whales. But until now we have had very little consolidated information on their more recent presence in this region," Dr James said.

To plug the gap, researchers compiled verified sightings and strandings recorded between 1964 and March 2025. These focused on the Benguela upwelling ecosystem - a nutrient-rich region off Namibia and the West Coast of South Africa - to better understand trends in presence and seasonality.

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