Summary of Abstract Submission

Abstract Submission No. IO50-11-0005PresentationOral


Bhavani E Narayanaswamy*1, Peter A Lamont1, Gordon LJ Paterson2, Lucy C Woodall2, Michelle Taylor3, Alex D Rogers3, Natalia Serpett1

1 Scottish Association for Marine Science, UK
2 Natural History Museum, London, UK
3 University of Oxford, UK


Little exploration has been undertaken on the seamounts in the SW Indian Ocean and consequently little is known regarding their biological ecosystems. A UK funded expedition (2011) was launched to sample 5 seamounts along the Ridge system. Seamounts located to the south and centre of the ridge lie in a region of high current velocities and enhanced primary production, whilst the more northerly seamounts lie under the Southern Indian Ocean gyre, a region of weak currents and low primary productivity. The focus was to sample fauna across different size classes to elucidate what species inhabited these unexplored seamounts. The video footage and stills images show a range of highly diverse and complex habitats on the seamounts. Numerous types of large enigmatic fauna were observed, including corals and sponges, with new species being described. In addition, smaller macro- and meio-fauna have been studied across the seamounts with an attempt to relate them to the habitat from which they have been collected, e.g. sand, coral rubble, coral framework etc. and noticeable differences have been observed. Coral rubble material has also been examined with an unexpected high abundance and hidden diversity of fauna residing within the coral itself. From ROV video footage there was evidence of human impact from trawling with trawl scars, large areas of bare rock as well as lost fishing gear including lobster pots and gill nets. Analysis of samples also found high levels of microplastics in the sediment, which is surprising considering the distance of the seamounts from land.