The MUC at the crane, being relocated on bord FS Sonne.

What goes down, has to come up again

Hi! I’m Freddy and I’m starting my PhD studies.
The deep sea floor is what interests me. More accurately, what type of copepods inhabit the sediment. These animals belong to the crustaceans. They can be found swimming in the water column, above and within the sediment. They call all aquatic systems their home – freshwater, brackish and saltwater. My task is to study the diversity and distribution of meiofauna within the Aleutian Trench. Meiofauna organisms, which include copepods, range in size from 0.032 mm to 1 mm. There are exceptions of course, such as the free-swimming copepods, the Calanoida, which can be relatively large. Meiofuana is very important for the ecosystem, but what biologist would not say that about his or her study animals. On the one hand, copepods serve as a food source, sometimes for juvenile fish and filter feeders, but are also relevant for the nutrient cycle, as they further decompose organic material and thus makes it accessible for other organisms.

This particular expedition is my third, but my first time in the North Pacific or within the Pacific at all. I’m originally from the Ruhr area in the western part of Germany, but this work took me to the shores and the sea. I reduced myself from millions of people around me to just a few crew members and scientists – more or less detoxing.

On the research vessel I’m in charge of the MUC – the multi-corer. Ours can punch out 20 cores of sediment simultaneously – if it succeeds. My first action as the gear leader took place on the 26.07.2022 – with full success! Hopefully my stroke of luck continues and I will go home with enough samples. Back home in Wilhelmshaven, these samples will be centrifuged to separate the organisms from the sediment. Then they will later be analysed morphologically and genetically. My task is to investigate the distribution and diversity of the meiofauna – animals with a size between 0.032 and 1 mm. The first station had a depth of “just” 3500 m, while the upcoming deeper ones up to 7000 m..
Let’s go!

Freddy Bonk
Senckenberg am Meer, German Centre of marine Biodiversity Research, Wilhelmshaven

A copepod (genus: Mesocletodes)
The MUC is taken out of the container at the beginning of the expedition.
MUC with 20 tubes, ready for use.
Insertion of the MUC.
The MUC comes back from the seabed with filled tubes.
When betting the MUC back, care is taken that the sample does not fall out of the tube at the last moment.
A successful mission, only one tube is empty. Enough samples for all research groups.
Today there was a by-catch. A jellyfish came on board with the MUC.
The tubes are secured before they are taken out of the MUC so that the sample keeps safe.
The tubes are removed and the samples prepared for further distribution.