The Magic Gear
By Santiago Pineda Metz
And so they days pass by, and here we are almost finishing our magical work. Fear not, I did not misuse the word “magical”, and fear not my dear reader, I will explain a bit more about this.
Our work on board RV Polarstern during PS96 was done using a gear that is known as Multi-Boxcorer , but it’s original name is Mehrfachgreifer, MG for short. However, the real name of this little monster is “Magic Gear”. Built in the late 1980’s the MG is a coring machine made out of steel, it counts with 9 small boxes where the sample ends up, and a camera can be mounted to its frame to take underwater pictures of the sea floor. If you’re still wondering about the “little monster” part, the MG wins this title thanks to the area it can sample (around 2.3 m2) and the weight it has (around 1.7 tons when fully assembled).
During PS96 we took the MG with us to continue the collection of benthic samples that started two years ago during the PS82 expedition at the Filchner region. In total we deployed the MG 11 times, but it only got 10 samples out of those. But fear not, this wear is a lot more effective than it seems, although it struggles with sandy floors, since the sand seeps through the small opening in between the box and the shovel that close it. Another enemy of this gear are solid bottoms, since the steel is not stronger than these floors (trust me, we tried it, and smashed the MG a bit…).
On each of the successful deployments, the MG team sat on deck and sieved the mud that was in each of the boxes. This work usually takes 1 hour or a bit more. For each of the cores we have a small 5L barrel, where we put what we sieved on deck. Later on we fix the samples in formaldehyde with borax, and we store it in a cage pallet until Polarstern arrives back in Bremerhaven in Germany. Once back in the lab, we sort out the samples and identify the organisms that are there. With this first work we can then calculate the abundance and biomass of each of the benthic groups, data we use to later on describe the distribution patterns of these groups.
So far we have no hard data, since we haven’t returned to Bremerhaven (makes sense, doesn’t it); hence, I would like to apologise to any person that was expecting a bit more data out of this small text. With that, I think I’m almost done with my description of the magic work we did during PS96. The thing I’m forgetting is to mention that for working with the gear, you need a good team, and since I have one, I prefer to pluralize everything; also to use this last line to thank Cheps, Dieter, Emi, Enrique and Nils for the help.
Now yes, done, check check. Hope you liked it!*
Un abrazo grande
Santiago, AWI
