A new scientific study has revealed a devastating decline in African penguin populations off the coast of South Africa, with more than 60,000 birds starving to death over the past two decades. The findings, published in Ostrich: Journal of African Ornithology, highlight how collapsing sardine stocks—driven by climate change and unsustainable fishing—have pushed the species to the brink of extinction.

Catastrophic losses at key breeding colonies

Researchers found that between 2004 and 2012, more than 95% of African penguins at two of the species’ most important breeding colonies—Dassen Island and Robben Island—died due to lack of food. African penguins rely heavily on the sardine species Sardinops sagax, a vital source of fat and energy that enables them to survive their annual moulting period.

Dr Richard Sherley from the University of Exeter, one of the study’s authors, said these mass losses were not isolated events. “These declines are mirrored elsewhere,” he noted, adding that African penguins have suffered a population decline of nearly 80% in the last 30 years.

African penguins undergo a dramatic process each year in which they shed and regrow their feathers to maintain insulation and waterproofing. During this moulting phase, which lasts around 21 days, the birds cannot enter the water and must rely solely on stored fat reserves. “If food is too hard to find before they moult or immediately afterwards, they will have insufficient reserves to survive the fast,” Sherley explained.

Many penguins that fail to find enough fish before moulting are believed to die at sea, with carcasses seldom washing ashore.

Sardine collapse driven by climate change and overfishing

The study shows that the biomass of sardines off western South Africa has remained at just 25% of its historical maximum in all but three years since 2004. Scientists attribute this collapse to two major factors:

  • Changes in ocean temperature and salinity, which have disrupted sardine spawning.
  • High levels of commercial fishing, which remain intense despite dwindling stocks.

Climate change has altered marine ecosystems in the Benguela Current, one of the world’s richest fishing grounds. As waters warm and become more saline, sardine reproduction and survival rates drop sharply, leaving predators such as penguins, cormorants, and Cape gannets with little to feed on.

In 2024, African penguins were officially classified as critically endangered, with fewer than 10,000 breeding pairs remaining—one of the steepest declines seen in any marine bird species worldwide.

Conservation efforts offer hope, but time is running out

To protect the endangered birds, the South African government has restricted purse-seine fishing—where large nets encircle entire schools of sardines—around six major penguin breeding colonies. This ban aims to increase prey availability during critical periods, especially before and after moulting.

“Creating these no-fishing zones will increase access to prey for penguins at critical parts of their life cycle,” said co-author Dr Azwianewi Makhado from South Africa’s Department of Forestry, Fisheries and the Environment.

Conservationists are also working on:

  • installing artificial nests to protect chicks,
  • managing predators that threaten eggs and young birds,
  • and hand-rearing weakened adults and chicks when necessary.

However, experts warn that such interventions are not enough unless fish stocks recover.

Experts call for urgent fisheries reform

Marine biologist Professor Lorien Pichegru from Nelson Mandela University, who was not involved in the study, described the findings as “extremely concerning”. She noted that the study only covers survival data until 2011, yet “the situation has not improved over time”.

According to Pichegru, the collapse of sardine stocks reflects “decades-long mismanagement of small fish populations in South Africa”. She warned that low fish numbers threaten not only penguins but also other species that rely on sardines as a staple food source.

“These small fish stocks need urgent rebuilding,” she said. “Not only for African penguins but also for other endemic species depending on these stocks.”

A global alarm for marine biodiversity

The African penguin’s steep decline is seen by scientists as a warning sign for marine ecosystems worldwide. Sardines and anchovies form the base of many coastal food chains, and their disappearance could destabilise entire oceanic regions.

For India’s coastal communities—particularly along Karnataka’s shores—such international research is a reminder of the fragile balance between marine biodiversity and fishing pressures. Similar challenges have been documented in Indian waters, where climate shifts and overfishing continue to affect local fish populations.