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    Adélie penguin diet: a pilot study directly comparing data from stomach flushing with faecal DNA analysis

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    Document Number:
    WG-EMM-18/29
    Author(s):
    B. Deagle, J. McInnes, L. Emmerson, M. Dunn, S. Adlard and C. Waluda
    Submitted By:
    Dr Louise Emmerson (Australia)
    Approved By:
    Dr Dirk Welsford (Australia)
    Agenda Item(s)
    Abstract
    • The diet composition of key species of penguin is currently monitored as part of the CCAMLR Ecosystem Monitoring Program (CEMP). Stomach lavage techniques are used in order to identify prey composition and mass. Analysing prey DNA in faeces may be a useful, less invasive, approach to complement existing diet monitoring.
    • We undertook a pilot study to directly compare these two methods using Adélie penguin Pygoscelis adeliae samples collected from Signy Island, South Orkneys during crèche (December/January) in 2014/15 and 2015/16.
    • Each method produced a similar pattern of penguin diet, with a shift from almost exclusively krill in 2014/15 to a mixture of fish and krill in 2015/16. Stomach flushing allows some additional information to be collected (e.g. prey size and meal mass). However, faecal prey DNA allowed more comprehensive sampling and DNA markers identified higher taxonomic diversity of fish prey.
    • Use of faecal DNA analysis provides an opportunity to establish CEMP as a global leader in long-term monitoring of seabird diets using this non-invasive methodology and could significantly increase the spatial range of data obtained for CEMP.
    • Further comparison between methods with additional penguin species (chinstrap, macaroni) and adoption of a standardized genetics methodology is essential for faecal DNA diet analysis to be used as a CEMP monitoring tool.
    • Some in-kind resources are available for continuing this research, however support from the CEMP special fund would allow for the directed research needed for establishment of faecal DNA analysis monitoring methods tailored to the requirements of CEMP.