Low-cost fishing exclusions improves penguin conservation in Africa

No-take zones can be important tools within an ecosystem-based approach to achieve sustainable fishing and re-establish ecosystem integrity. However, the potential benefits of these exclusion zones for vagile species such as... [ view full abstract ]

No-take zones can be important tools within an ecosystem-based approach to achieve sustainable fishing and re-establish ecosystem integrity. However, the potential benefits of these exclusion zones for vagile species such as small pelagic fish and top predators remain questionable. In South Africa, the population of the endemic African penguin Spheniscus demersus has halved since 2004. They predominantly feed on sardines and anchovies which are also the target species of the purse-seine commercial fishery. Since 2008, a 20 km radius experimental purse-seine fishing exclusion has been initiated around two pairs of penguin colonies with alternating closure regimes in three-year cycles. Here, we report results of the experiment around two of the largest African penguin colonies, Bird and St Croix islands in Algoa Bay, currently supporting over half of the global population. Between 2012 and 2017 we collected information on the birds’ foraging performance and reproductive success and the acoustically-determined relative abundance of pelagic fish around their colonies. We related these to fishing exclusion patterns and size of catches in the bay, while controlling for monthly environmental conditions. In parallel, we compared fishing patterns (locations, landings) during and outside closures to estimate the potential socio-economic cost to the industry. Our results show that while costs to the fishing industry remained relatively low, fishing exclusions largely benefited penguins in terms of breeding success and foraging performance.  Results of the experiment support the expansion of similar measures to improve the conservation status of African penguins and other predators reliant on small pelagic fish.