Heading back to Cape Town

Weekly biodiversity report — 30 January 2008

Polarstern ANT–XXIV–2 — weekly report 7

Crinoid from Rauschert dredge. Photo: T. Riehl, Uni of Hamburg

Still heading north on the Greenwich meridian transect, we resampled the benthic site at 52° S with the Lander sediment profiler, two multicorers, a boxcorer and the epibenthic sledge. However a storm of force 9 interrupted us before we could complete the work to determine whether the benthic community had changed after a phytoplankton bloom. In marginal conditions, we retrieved the amphipod trap — just in time before the heavy seas washed the after deck.

Now we are back on station at nearby 49° S with a deep CTD underway to 3,900 m. We are poised ready to deploy one final set of benthic samplers — a multiple corer, a box core and an Agassiz trawl. Packing the labs will be rushed but we are jubilant to get the last samples in this welcome moment of moderate weather.

Octopus with ink from 600 m Agassiz trawl. Photo: T. Riehl, Uni of Hamburg

Isopod Natatolana sp., 600 m Agassiz trawl. Photo: T. Riehl, Uni of Hamburg

Crustacean Chorismus sp., 600 m Agassiz trawl. Photo: T. Riehl, Uni of Hamburg

While each group is preparing their section of the voyage report and posters, we have discussed the carbon flux results and how the various components of the ecosystem are coupled. This multidisciplinary study, sampling throughout the water column and into the sediment, will help to explain the functioning of the Antarctic ecosystem. On return to Cape Town next week, we will present our results to politicians and the press at a reception. Meanwhile, another team is preparing for their coming voyage.

Everyone onboard has contributed to this education and outreach campaign, with the encouragement of the voyage leader Professor Ulrich Bathmann and Captain Uwe Pahl. We thank them all for graciously sharing their esults and interrupting their work for photographs. Our partners in the Alfred Wegner Institute, the Census of Marine Life and Equipe Cousteau have contributed to the successful campaign. In the spirit of the International Polar Year, we have attempted to make Antarctic biodiversity studies available to anyone who is interested, particularly the new generation of Antarctic researchers.

Asteroid echinoderms from 600 m Nordanleger near Neumayer. Photo: T. Riehl, Uni of Hamburg

Amphipod Epimeria rubrieques from 600 m. Photo: H. Robert, Royal Belgian Museum of Natural Sciences

The photos this week show some of the beautiful animals collected from the samples during Polarstern's ANT 24-2 voyage, to illustrate the great diversity of forms that make up the ntarctic ecosystem. We hope that you have shared with us some of the excitement of our discoveries on board.

Victoria Wadley
Census of Antarctic Marine Life & Australian Antarctic Division