A Finger On The Pulse Of Penguins

Marine ecosystems are highly dynamic and frequently experience changes resulting from natural and human-induced processes. Some of the most productive ones are the four upwelling systems situated at the eastern edges of the Atlantic and Pacific oceans.

- Dr Alistair Mcinnes

These systems are rich in prey species, such as the small pelagic fish that are an important food source for many top predators. And when prey supplies fluctuate, the predators’ populations respond.

The Benguela Upwelling System, adjacent to Angola, Namibia and South Africa, is one of these four systems and is home to many seabird species that play an integral role in such ecosystems. Among the Benguela seabirds are three endangered species: the African Penguin, Cape Gannet and Cape Cormorant, which feed on small pelagic fish, mostly anchovies and sardines. The status of the African Penguin population is cause for particular concern, due largely to the limits imposed on the birds’ ability to disperse and adapt to their prey’s movements.

During the breeding season the penguins are restricted to a small foraging range of 20–40 kilometres around their colonies. Within this zone, prevailing conditions play a crucial role in determining the success of the birds’ breeding effort. A key limitation is the availability of their prey, which is also targeted by the purse-seine fishery, the largest fishery in South Africa in terms of biomass extracted. This competition for resources, together with threats linked to emerging industries and maritime operations, means that there is a clear and urgent need to develop tools to monitor the penguins’ habitat at a scale appropriate for effective management. The African Penguin population has plummeted by more than 70 per cent since the turn of the century – and we need to be able to convince stakeholders to implement solutions that will reverse this downward trend.