The epibenthic sledge (EBS) is just returning from the deep with a sufficient amount of mud.    

AleutBio backstage

The success of a deep-sea expedition depends on many factors. Some of them can hardly be influenced (the weather, for example). Others depend on precise planning and, above all, a lot of work. The samples that arrive here on deck every day are visible to everyone, the “main act” so to speak. However, the many small steps that take place in the background, which ensure that everything is documented and processed accordingly for later work on the deep-sea material, often remain hidden. Considering that our material is highly precious, each collected sample or individual will be recorded and will get a number in the on board data base. And as we have now approached halfway through the expedition, it’s time for an interim score.

After 25 working days, we deployed 88 stations, i.e. with epibenthic sledge, plankton net & Co. 88 times to the deep sea and back, which (roughly estimated) corresponds to about 750 km or roughly the distance from Hamburg to Munich. This resulted in 1,200 individual samples that have been already sorted on board, which will be further investigated at home in the laboratory. But the sorting will also continue on land for a long time. Yet, already, a large number of animals have been picked out of the sediment one by one by many diligent helpers. This number will likely increase significantly in a few months when all the samples have been sorted. We hope to gain a better understanding of the distribution of individual animal groups and their adaptation to different habitats (yes, even in the apparently “monotonous” deep sea, the habitat can be quite variable!).

There are still a few days ahead of us and the weather seems to be holding up. As such, we are confident of obtaining more samples from great depths. Working on them will also keep us busy for some times after the expedition. But we hope that the material will then help us to solve some mysteries of the deep, but will probably also raise many new questions (just stay tuned!).

Karen Jeskulke (DZMB – Senckenberg am Meer, Hamburg), Franziska Iwan (DZMB – Senckenberg am Meer, Wilhelmshaven), Stefanie Kaiser (Senckenberg, Frankfurt)

The multi-net for sampling floating specimens in the water column (=plankton) is deployed.  
A full catch of the Agassiz trawl or AGT for short. The latter serves to sample larger specimens that are visible to the naked eye, such as mussels or sea stars.
Samples are taken from the EBS, more precisely from two containers (or cod ends) at the very end of the nets.
Because the samples are very muddy, the excess sediment is removed by careful sieving, almost immediately exposing organisms that can be picked directly from the sieve for further study.
Sorting the larger specimens from the AGT is teamwork and can take up to two hours after the gear arrives on deck. Specimens are therefore discriminated into main groups such as crustaceans or gastropods (snails).
Franziska Iwan processing plankton samples from the multi-net. Plankton samples are certainly much cleaner than those from the seafloor, but the work is no less time-consuming as the nets are full of specimens.
A dish of unsorted deep-sea organisms and more. We collect all material brought to the surface, which sometimes also includes plastics (in green) or other artificial materials.
After sorting the material, each individual is documented, with the most interesting specimens being photographed. The photo shows database manager Karen Jeskulke (in the front) and photographer Anne-Helene Tandberg (in the background) in action.
The deep-sea environment is a cold one. So best for the material is to keep it cool at all times. Here the cold storage of RV Sonne is shown, with parts of our samples collected so far.
Taking a closer look – jars of specimens fixed and ready for the journey home back to Germany to be examined more fully.
In contrast to samples from the AGT, material from the epibenthic sledge, since the specimens are only a few millimeters in size, takes a long time under the microscope to be sorted and identified. Here it is Katharina Kohlenbach (background) and Sarah Gerken’s turn with this time-consuming task.
Sneak preview into our lab fridge showing dozens of individual vials = the result of weeks of concerted microscopic work.
The final and arguably most important step is to enter all stations, all samples and all individuals into the “onboard” database, which will ensure long-term tracking – well beyond the end of the expedition