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Publication - Professor Peter Barham

    Collapse of South Africa's penguins in the early 21st century

    Citation

    M.;, [VCRJ, R.;, [VA & Barham, P, 2011, ‘Collapse of South Africa's penguins in the early 21st century’. African Journal of Marine Science, vol 33., pp. 139-156

    Abstract

    The number of African penguins Spheniscus demersus breeding in
    South Africa collapsed from about 56 000 pairs in 2001 to some 21 000
    pairs in 2009, a loss of 35 000 pairs (>60%) in eight years. This
    reduced the global population to 26 000 pairs, when including Namibian
    breeders, and led to classification of the species as Endangered. In
    South Africa, penguins breed in two regions, the Western Cape and Algoa
    Bay (Eastern Cape), their breeding localities in these regions being
    separated by c. 600 km. Their main food is anchovy Engraulis encrasicolus and sardine Sardinops sagax,
    which are also the target of purse-seine fisheries. In Algoa Bay,
    numbers of African penguins halved from 21 000 pairs in 2001 to 10 000
    pairs in 2003. In the Western Cape, numbers decreased from a mean of 35
    000 pairs in 2001–2005 to 11 000 pairs in 2009. At Dassen Island, the
    annual survival rate of adult penguins decreased from 0.70 in 2002/2003
    to 0.46 in 2006/2007; at Robben Island it decreased from 0.77 to 0.55 in
    the same period. In both the Western and Eastern Cape provinces,
    long-term trends in numbers of penguins breeding were significantly
    related to the combined biomass of anchovy and sardine off South Africa.
    However, recent decreases in the Western Cape were greater than
    expected given a continuing high abundance of anchovy. In this province,
    there was a south-east displacement of prey around 2000, which led to a
    mismatch in the distributions of prey and the western breeding
    localities of penguins.

    Full details in the University publications repository