Browsing by Author "Waller, Lauren"

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    The African penguin Spheniscus demersus : conservation and management issues
    (2011) Waller, Lauren; Underhill, Les
    The African penguin is a southern African endemic, with its breeding distribution within the Benguela Upwelling Ecosystem. The IUCN conservation status of this species was re-classified from ‘Vulnerable’ to ‘Endangered’ in 2010. This thesis investigated some aspects pertinent to the species’ conservation and management. Time series of population estimates of African penguins and fish biomass were available in South Africa since the late 1980s. This study analysed the fish biomass at a stratum scale, which is a finer scale to that of previous studies which looked at biomass estimates as a whole. The strata range in length from c. 155 km to c. 280 km in length. The number of African penguin breeders and adult moulters were found to be positively correlated with fish biomass estimates, although results of the spatial relationships were unexpected. The islands which displayed the strongest relationships were Dassen Island and Robben Island. These islands are only c. 50 km apart, and it is expected that they would experience similar oceanographic conditions. However, the colonies at these islands were found to respond differently to fish biomass estimates. While the number of Dassen Island birds were found to be positively correlated with biomass estimates within the strata in which the island is found, the number of Robben Island birds were correlated with biomass estimates of the stratum to the south and east of the island. Weaker relationships were found for the remaining colonies. This study suggested that the period of moult is of critical importance to the survival of the penguin, an aspect that needs to be incorporated into the Ecosystem Approach to Fisheries modelling.