Day 6: Friday 26 June 2020
A really successful ROV day with most beautiful imagery from the deep-sea floor, as well as samples that will help understanding the biodiversity across the north Atlantic abyssal plain, came to an end last night.
It was followed by a busy night deploying “Ursula”, the newly christened EBS (Epi-Benthos-Sledge), which is dragged over the seafloor to collect the upper sediment layer. Then came the box corer, which has a big shovel that digs into one spot of the seafloor rather than shaving off a large area. The final instrument of the coring class is the MUC, multicorer, that pushes cylindrical shaped tubes of about 10cm in diameter and 50cm in length into the seafloor. This is a good opportunity to introduce some more of our scientists to you – namely those who are in charge of these devices!
Stefanie Kaiser is looking after Ursula, the EBS. She is from Łódź University in Poland and, despite being German, representing a whole foreign research team who couldn’t join the cruise themselves because of Coronavirus travel restrictions. She enjoys working with isopods, not only because they are fundamental food chain fellows, but also because they are ancient creatures and therefore suitable for long term studies as they can tell stories from the far past but also from recent changes. To understand biodiversity and its transformation in a changing climate, isopods and amphipods are essential indicator species.
Anne Nina Loerz (CeNak, University of Hamburg) loves amphipods. Wherever she is, these small little crustaceans show up. Anne has been studying them for ages and, similar to isopods, they form the basis of the food web. They are key players in all marine environments down to the deepest trenches- and certainly in habitats where we will take samples during IceAGE3. Moreover, they also act as abyssal police(speci)men and deep-sea garbage collectors, i.e. cleaning up carcasses of other dead marine inhabitants. Anne promised to discover new species during this cruise, so stay tuned!
Nancy Mercado Salas from CeNak is taking care of the MUC (multicorer) and the meiofauna that is kept in its tubes after retrieval. She particularly likes ‘digging in the mud’ and the exciting fact is that at least 80% of the species are still unknown – meaning that in every MUC, there is something new to discover! In the remaining 20% that are known, Nancy’s favourite animals, the copepods (another type of little crustacean), make up one of the largest group of all meiofauna in the benthos. As with the other crustaceans, they serve to prove the theory on biodiversity transition that is connected to ocean acidification and a rise in temperature.