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The epibenthos (seabed surface living animals) at the deep site sampled last night near the Mertz Glacier was relatively low in diversity, and dominated by a few large solitary tunicates and sponges. Some species, such as the green sponge Latrunculia, are found all around the coast of Antarctica and are known from shallow coastal locations as well as these deeper places. The scientific highlight of this site was the discovery on the high definition photographs of highly pigmented patches on the sediment surface. The colour is very like the patches of photosynthetic microorganisms found on sediments in shallower places but at this depth (1300 m) no light penetrates and so photosynthesis is not possible. The most likely explanation is that they are caused by organic material from the upper waters that has sunk to the bottom fast enough to retain photosynthetic pigments. This explanation is consistent with the CTD cast at this site which indicated patches of photosynthetic microorganisms at various depths through the water-column. As I write, these surface sediments are being examined under the microscope to see whether the source of the pigments can be identified. Regards, Martin and Sarah.
Map
A map showing Australia and Antarctica. The map shows the journey of one voyage that has occured in the season, with each route highlighted in a distinct colour.