Last preparations during the transit
Plankton pelagic team preparation
This morning, boxes containing IRD (Institut de Recherche et de Développement) research equipment were brought down by crane from the upper bridge to the lower back deck. The material was removed from its packaging, ready to be used to next day.
Among the different collection instruments, there IKMT net (Isaac Kid Midwater Trawl) was prepared by the Marion Dufresne’s crew. The purpose of this net is to capture nekton, i.e. organisms of an intermediate size (a few cm) between pelagic fish and zooplankton (animal plankton). This net can go down to 2000m depth, and should allow the team to capture shrimps and small fish. Two measuring devices will be attached to the net to record collecting parameters (depth, temperature).
Pelagic Glider’s team preparation
The pelagic team is in charge of prepping an incredible piece of technology: the Seaexplorer glider.
The glider is 2.70m in length when fully deployed. It has no means of propulsion, can go down to a depth of 700m and reach the surface by itself from where it will be able to communicate with its pilot in Meyreuil (South of France). Thanks to its energy efficient way of traveling, it is able to stay at sea for a very long period of time and will record a lot of data (temperature, depth, water conductivity). It will also be equipped with a hydrophone, which passively records any sound that reaches it. This will allow us to know if any marine mammals are present in the area and to identify the species.
Marine birds observation
Hélène and Anjara observed a “giant albatross” - which was unfortunately too far to be photographed – and several petrels “à menton blanc” (Procellaria aequinoctialis) that by chance have been photographed.
“Trawl and dredge” benthic team preparation
Several members of the team prepared the beam trawl nets. They made real work of seam!
This net will be placed at the bottom of the trawl where the specimens will be captured during trawling. It will be opened above a big plastic basin on the deck at the end of the operation. The team will proceed to an initial sorting by taxon (groups of organisms, i.e mollusc, crustaceans…).
It is then all taken to the laboratory for further sorting. Here, organisms will be observed in more detail and eventually photographed before being prepared for conservation (in alcohol, for example). Meanwhile, the “Warén” dredge has been reconditioned by replacing its metallic nets. This was done in the presence of Anders Warén, the man who conceived that dredge in 1980. It’s a genuine “off road” tool for dredging operations, adapted to rocky and irregular sea bottoms. The dredge can go anywhere, and, normally, never gets stuck.
