A new crisis unfolds as African penguins clash with fishing fleets for dwindling fish stocks. A sweeping analysis shows how these birds now enter direct competition with commercial vessels when prey runs low. This pressure intensifies the struggle of a species already near collapse.
Growing Threat from Fishing Fleets
A study from the University of St Andrews reveals that Critically Endangered African penguins forage far more often in the same waters as commercial fishing boats in years with scarce fish. This pattern raises the stakes for a species suffering rapid decline. The research, published on November 17 in the Journal of Applied Ecology, introduces a metric called overlap intensity. This metric measures where penguins and vessels intersect and how many penguins face this pressure.
Population Declines and Heavy Fishing Pressure
African penguin numbers have fallen by nearly 80% over the past thirty years. Competition with fisheries plays a major role in this collapse. Local fleets target sardines and anchovies, which penguins rely on for survival. Many boats use purse-seine nets that trap schooling fish by encircling them with large walls of netting. Lead author Dr. Jacqueline Glencross from the Scottish Oceans Institute explains the aim of the study. She says the team wanted a clearer method to assess how many penguins face risks when fishing occurs nearby rather than only where the overlap takes place.
Tracking Data Reveals Alarming Overlap
The team analysed tracking data from penguins on Robben and Dassen Island. Scientists from the University of Exeter, the South African Department of Forestry, Fisheries and the Environment, and BirdLife South Africa contributed to the work. Their findings reveal sharp increases in overlap during years with weak fish stocks. In 2016, when fish biomass was low, about 20% of penguins foraged in the same areas as active vessels. In years with stronger fish stocks this figure dropped to around 4%. These results show how competition intensifies when prey becomes scarce. This situation creates major risks during chick-rearing because adults must find food quickly to feed their young.
A New Tool for Conservation and Management
By measuring overlap intensity across the entire population, the researchers created a practical tool for assessing ecological risk. This tool can help guide ecosystem-based fishery management. The study also supports efforts to design dynamic marine protected areas that respond to real-time shifts in predator and prey behaviour.
Legal Action and New Fishing Closures
African penguins recently became the focus of a major South African court case that challenged weak fishing restrictions near breeding colonies. Earlier this year conservation groups and fishing industry representatives reached a high court agreement. They recognised the need for closures around penguin colonies. Following this decision the South African government reinstated stronger no-fishing zones near Robben Island, a key colony in the study. Dr. Glencross says the findings reveal why these measures matter. She notes that previously unprotected areas with high overlap intensity posed the greatest risk for penguins.
