'Our measurements of environmental parameters of the sediment and the water column will contribute to answer the question, why there are such similarities between habitat use of the deep-sea and below the former ice shelf.' The oceanographer Enrique Isla is excited about further processing the collected data back in the Marine Sciences Institute (ICM) in Barcelona. Myriads of single-celled algae that sink down to the seafloor are literally grazed by herds of sea cucumbers. This species, its bigger 'sister' Scotoplanes globosa and other relatives according to their feeding mode are referred to as grazers. Maybe this is the reason why this animal is aptly named glacialis (icy) especially with regard to our confirmatory findings on the opposite pole – Antarctica. The sea cucumber Elpidia is probably the most prominent deep-sea animal but is also known to occur in shallow Arctic waters. Preliminary results show that a unique macrofauna exists in conjunction with the ice shelf. This second encounter brought back chief scientist Julian Gutt's memories of his first trip to Antarctica and his PhD thesis 21 years ago. 'During my nine expeditions to Antarctica, the only time I have seen the two most abundant species of sea cucumbers was below the far bigger Filchner-Ronne ice shelf further south.' But locally in the Larsen B region, they occurred rather frequently at depths of merely 200m. Until now, stalked feather stars have only been found sporadically and then only below 800m water depths in this sector of Antarctica. These deep-sea inhabitants belong to a group called echinoderms. Here, sea cucumbers and stalked feather stars are the main representatives. Instead, underwater video footage and catches of towed sampling gear revealed the dominance of typical deep-sea animals and corresponding life forms. This is surprising since Antarctica's seafloor communities are known for their rich assemblages of sessile sponges, cnidarians and moss animals. Obviously, prosperous life did not exist in the area where the Larsen B ice shelf broke off three years ago. This 'white spot' with regard to biodiversity research gave rise to the following questions: What kind of life actually existed under the former floating ice shelf which was up to several hundreds of meters thick? What are the prospects for the future after the collapse of the ice shelf? The main aim of the current Polarstern expedition to Antarctica is the investigation of marine ecosystems under the former Larsen ice shelf.

Underwater shelf