Bottom-up effects of a no-take zone on endangered penguin demographics

An 18% increase in chick survival for endangered African penguins (Spheniscus demersus) was observed during a three-year fishery closure around Robben Island, South Africa. This localized no-take zone led to a predicted 27% higher population compared to continued fishing, demonstrating bottom-up benefits for highly mobile marine predators. However, the population decline persisted due to high adult mortality linked to broader-scale prey scarcity. The study highlights that while small no-take zones can support predator demographics, they must be part of larger, ecosystem-based conservation strategies.

Sherley, R. B., Winker, H., Altwegg, R., van der Lingen, C. D., Votier, S. C., & Crawford, R. J. M. (2015). Bottom-up effects of a no-take zone on endangered penguin demographics. Biology Letters, 11(7), 20150237. https://doi.org/10.1098/rsbl.2015.0237