Besides all the spectacular events of any journey to the Antarctic, there is the everyday life of “normal” working days even on a research vessel. As was already mentioned in previous logbook entries, I belong to the benthos team. Which means, I deal with animals restricted to the sea floor. To be more precise, I am a specialist for deep-sea bristle worms (relations of the lugworm), and I am also familiar with deep-sea isopods. When I talk about these animals to non-benthologists, my enthusiasm is seldomly shared by them. However, these two groups not only constitute more than 50% of all deep-sea organisms, but also show a dazzling variety of shapes and forms. A sound knowledge of these groups is therefore essential for deep-sea research. While samples from the water column contain clean animals that are easy to sort, benthic samples are notorious for consisting of not much more than mud, at least at first glance. An untrained eye would not see anything special in the tonnes of mud our gear brings up into daylight. To us, on the other hand, this sediment is the door to the unfathomed world of the deep sea.
Thousands of tiny organisms, no bigger than 1-5 mm, are hiding inside the mud. Between stations our everyday life therefore consists of washing this mud very carefully through fine meshed sieves, picking every single animal under a stereo microscope and assigning it to a large organisms group. So far, we have sampled four stations, the last one about a week ago. Three of these stations are sorted until now, so we feel optimistic that we will have sorted two thirds of our samples by the end of the expedition. The remaining samples are fixed and stored cool to be sorted at the laboratories at home. Four people need about one to two weeks to sort one sample. Depending on the sediment type, this requires more or less patience (usually more), as ship movements also keep the sample under the stereo microscope moving, and resuspended mud particles make it difficult to see anything. In spite of, or maybe rather because of this strain, we always enjoy discovering “old friends” (species that occur frequently and are already well-known). If somebody finds a totally unknown species, we all become outright enthusiastic. As the deep sea, and especially the deep Southern Ocean, is poorly investigated, the joyful exclamation “Wow, what on earth is this? I have never seen anything like this before!” is heard relatively often in our lab.
The caught animals help answer a great many scientific questions, by the way. Aside from the pure censusing, we can investigate their colonisation history, evolution and phylogenetic relationships. The focus of this expedition is the relation between atmosphere, water and deep-sea floor. It is quite remarkable how much life and scientific potential can be found in a handful of deep-sea mud.
Myriam Schüller, Ruhr University of Bochum
Photos: M. Schüller