Week 8 — 17-23 January 200817 January 2008Katja Guilini, University of Ghent
While the Polarstern did her utmost best to break through the pack ice towards the shelf, most scientists finished their practical station work and had the first look at the preliminary results. As member of the benthology team I work on the smallest, though surprisingly amazing members of the multicellular benthos, the Nematoda. These wormlike creatures are so numerously present and show such a great variability that they simply have to fulfil an important role down there. Because they are so small you need a microscope with high magnification to be able to identify them. Therefore and also because I plan to do some biochemical analyses on the nematodes found in the deep-sea sediments, my preliminary results on board would be limited to mentioning that the sampling we did by means of the multiple corer was successful so far.
But besides looking at which species the communities are composed of, I want to find out what they feed on and if different genera or species have preference for certain food sources on their menu. With these concrete questions in mind I set up an experiment in a cold container on board. I incubated 20 cores, taken with the multiple corer at Maud Rise, in a dark room at the temperature found at the bottom (0.5°C) and oxygenated the water. The only thing I couldn't simulate to make them feel at home was pressure. I took quite a risk by taking the samples from 2150m depth.
To keep bacteria and nematodes alive for several days I learned from predecessor to take samples from a depth down to 1800m to be on the safe side. But no risk, no fun, right? So, I injected these cores with different chemical substrates which enhance the growth of certain bacteria and labelled them with a marker (13C). If my nematodes feed on them I can trace this marker in their body tissues. I ran this experiment for 12 days. It was a great pleasure that Oliver Sachs and Eberhard Sauter joined me in this experiment and proposed to measure oxygen profiles in the sediment. And Henri Robert taught me how to extract bacterial DNA and lent me some material to do so. These analyses could add some really nice data to the final result and I'm very excited about it.
Yesterday I ended the experiment by fixing the last samples. I also had a look in the control sample to check if my nematodes were still alive (and thus feeding). I was so thrilled to see two crawling worms that I felt like announcing it through the intercom! However, I guess people would not have rushed down the stairs to share my enthusiasm as they did with the orcas. But that's ok, because I'm already glad you read through this little note about my work and came to the conclusion that nematodes are quit tough, little beings.
18 January 2008Angelika Brandt, University of Hamburg
My day started quite unspectacularly. After my morning routine of looking briefly into my computer files, I went to breakfast, expecting nothing special. I had just sat down when Uli, the expedition leader, approached me and asked whether I possibly wanted to join the first helicopter flight, starting at 9 a.m., and help the colleagues of IMARES from Wageningen, the Netherlands, with their top predator counts. Well, what was I going to say. Of course I was very happy and I immediately agreed. Originally I had planned to sort the last part of the sample from Maud Rise in the lab, but the sample is fixed well in alcohol and could wait.
I did not have much time, 15 minutes had to be enough to recharge the camera battery, then I rushed to the helicopter hangar and wriggled myself into the survival suit. We had to wear this suit today because overnight we had steamed further to the north, and the ice floes had become fewer, thinner and more fragile, so that the helicopter could not have landed on ice any more in case of an emergency. The thick pack ice had been replaced by open water. When I finally had taken my seat wearing the unwielding overall — I wonder how astronauts may feel — we started at once.
Jan quickly explains what my duties will be, and then we are in the air and surround the Polarstern twice to get a feeling for a 200-metre stretch which we are to survey on either side of the helicopter. Michiel marks the waypoints, Jan repeats, and then he gives the signal to start.
After the first 15 minutes I begin to wonder why all the seals and birds are on Michiel's side… am I blind? Is it that I can't recognize the white snow petrels over white ice floes? No, turns out I'm not, all of a sudden I see the first group of small Antarctic terns, and then we are passing ice floes with seals and a penguin on my side. The penguin is small — must be an Adélie, I say. Jan is not sure, Jürgen turns and surrounds the ice floe. The penguin grows, the Adélie changes into an emperor. A perfect demonstration of how an uneducated eye underestimates sizes and proportions. Now I know better and feel prepared, but we do not see any more penguins during our two-hour flight.
Jan is sitting in the front seat, beside the pilot. Those two therefore see most animals first. Jürgen the pilot, suddenly shouts: "There are whales ahead" — and plop, the helicopter is lying on its side so that Jan has a better view and can count more easily. Only seconds later Jürgen turns the helicopter on its other side to surround a group of five minke whales so that we can observe and photograph them — my stomach cries out for crackers! A short time later Jürgen spots the next group, another five minke whales, coming to the surface with curiosity, breathing and trying to figure out what was happening up in the air above them. We continue seeing groups of three, two, and finally one single whale. The show they present is gorgeous. Normally I work with small marine isopods from the deep sea, and I am used to look at small things. The sight of these beautiful creatures and the graciousness and elegance of their movements fascinates me all the more.
Whales are common in this area of light ice cover. They feed mostly on krill, which is quite abundant here in the summer, as we were told by the planktologists reporting on their catches.
After about two hours we return to the Polarstern. Jürgen flies around the ship one more time just for me, and then we land softly. I get out of the heli, ready to give the whole world a big hug! In the afternoon I work on a presentation and down in the lab on a sample, dreaming of my experiences. My colleague Myriam is flying in the meantime, and she even reports the sighting of a blue whale. Andre's photo of the blue whale's head is chosen as picture of the day. But I am happy anyway and thankful for 'my' minke whales, and will think of them for a long time.
It is nice to have one more day in the ice. By tomorrow we will already have left the field of pack ice, and then there are some 4,000 km of open water with few single icebergs between us and our port of call, Cape Town.
19 January 2009Jan van Franeker, Wageningen IMARES
Today was –again– a great day for me on board Polarstern. It started in a bit of shock, as Bram, doing the early morning shift in counts of birds and mammals on top of the ship, woke me up by calling me via the stand-by mariphone in my cabin. He excitedly reported seeing 'brown spots' which must sound weird and requires some explanation. Since my first marine science cruise on Polarstern, almost 20 years ago in 1988, I have been seeing occasional mysterious 'brown spots' while conducting the bird and mammal counts. They measure from several meters up to maybe a 100m in diameter. They are not easy to see if you're not constantly on the lookout. Only with variable success I have been able to convince other people that indeed 'something' was there in the water. In my view, the spots had to be zooplankton swarms, but most others were rather skeptical and offered alternative explanations that ranged from cloud-shadows to whale-shit and accumulated algae in the water. Zooplankton was considered not to swarm so close to the surface during daylight hours.
Over the years I have tried many times to set up a way to have a closer look at the mysterious brown spots, but never managed because it's not easy to change the planning of a big ship. But earlier on this voyage, we observed brown spots again, and this time from the helicopter. This led to a plan that abandoned the idea to use the ship to sample the spots, but instead aimed at using the helicopter! Chief scientist Uli Bathmann approved this ghost-hunt of a crazy Dutchman. So the IMARES team with the pilots and technicians of HeliTransair prepared a small net strong and heavy enough to be lifted as a sling-load under the heli. It sat waiting in the heli-hangar for a next opportunity.
And thus finally, this morning, that opportunity arrived. Around 09:00 we took off, flying to the last position on which Bram had seen the brown spots, and indeed we found them. Pilot Jürgen and technician Marcus skillfully maneuvred the heli above the spot and lowered the heli to about 5m above the water allowing the net to sink to about 15m depth. Then the heli slowly regained height to pull the net and its hopeful contents out of the water. I was so incredibly curious if our attempt had been successful, but had to be patient as flying back to the ship with a sling-load had to be done slow. The net was lowered to the heli deck, and yes, only then I could see that indeed our out-of-the-ordinary plan had been a success: the orange shining of krill was visible through the gaze of the net. The swarm proved to consist of very young small krill. Why these animals swarm and why so close to the surface is somewhat of a mystery. And rather than helping us to solve the complex biology of the Southern Ocean, it makes our task more complicated. Important things are going on in the surface layer of the water that will need new approaches in future studies.
This first bit of an answer to a 20 year long puzzle in my life means that the 19th January 2008 has been indeed a great day for me. But there have been many good days. In spite of the considerable time that Polarstern had to spend on 'logistic duties' for Neumayer on this voyage, the Dutch IMARES team already now can look back on a successful expedition. We were able to collect extensive data on distributions of marine mammals and birds and had excellent results from the fishing with our Surface and Under Ice Trawl (SUIT). The successful 'brown spot' action of today is the cream on the cake.
20 January 2008Mark Olischläger, Alfred Wegener Institute
Between me and the seafloor there is about 4,000 m of water. A barrier for scientists who want to understand the biology of the water column all the way down to the deep-sea floor, harder and harder to penetrate with increasing depth. Nevertheless, the beginnings of deep-sea research are already a century behind us. The foundation of deep-sea investigations was laid by the Challenger Expedition and the German Deep-sea Expedition. My great-great grandfather Franz Eilhard Schulze was involved in the analysis of these expeditions. He worked on the sponge fauna of the deep sea worldwide. When presenting results from her projects, Dorte Janussen, the sponge expert for this voyage, often refers to his work which is still an important reference for her work today.
It is nice to see that careful scientific work does last for so many years, and it is almost intimidating to imagine that more than 100 years later one of Franz Eilhard Schulze's main achievements in life, the assessment and understanding of the deep-sea fauna, is far from being completed.
For me personally it is very special to contribute a small part to the continuation to my great-great-grandfather Franz's life achievements. I analyse the fauna of the water column, but the plankton in the surface water will eventually die off. It will sink to the deep-sea floor, where it might be eaten by a sponge, and in that way the circle of life closes in two ways.
21 January 2008Brigitte Ebbe, Senckenberg
The mood on the ship is changing. In the stairwell there are sheets of paper on the walls with a red page-size exclamation mark which are very familiar to those who have been on Polarstern before. They announce deadlines for packing and delivering the packing and freight lists. Oh, yes, the packing lists, now where did I put them... After 54 days at sea, some realities of life have vanished into the background as we live in our own small world, despite emails and daily news from the internet.
The gods of the weather have been kind to us, the Polarstern is swaying very gently in the cat-paw waves, and even though there was snow on all the decks this morning, the sun came out often enough to call all those among us who have no laboratory work out on deck into the fresh air. Two days ago, this shifting weather made for a truly unique performance by nature. For about half an hour we admired a fiery red sunset over a nearly clear horizon — the story of the green flash was told once again. Close to the ship, however, snow showers passed by, and the flakes reflected the light to create an unearthly, nearly Armageddon-like shine through which the sun slowly slid below the horizon. We are now far north enough to have a few hours of darkness at night.
Conversations in the hallways begin to contain words like 'airport' and 'cruise report'. Thoughts, not only mine, turn towards homes we left behind so many days ago. But checking the laboratories, one also notices that station work is still in full swing, with everybody trying to collect as many data as possible during the few remaining days.
22 January 2008No entry.
23 January 2008Sarah Herrmann, Alfred Wegener Institute
This is what I always thought the Antarctic summer should be like: the sun is shining out of a blue sky, the unfathomable water has a beautiful blue colour, and we are surrounded by icebergs displaying a high variety of shapes.
So I am standing on the work deck at 7 o'clock in the morning, waiting for my turn. The CTD with 24 water bottles, each closed at a different depth all the way down to the seafloor which here lies more than 5,000 m below the surface, is a sampling device in high demand among oceanographers and biologists.
I personally take samples from different depths to determine on board the chlorophyll concentrations down to 200 m. Additionally I take samples for the measurement of particulate organic carbon (POC) down to the seabed, to be made later on land at the AWI. These data provide important reference information needed by every biologist dealing with the life of animals in the water column.
Before me, however, the chemists can take their samples. They measure oxygen and carbon dioxide content of the water. To avoid contamination of their samples with intruding air, they have absolute priority.
Once I filled all my water bottles, I can go to my lab where two filtration apparatuses are waiting for me. I turn on the vacuum pumps to make the water run faster through the very fine filtration platelets, and I wait for the required volume of water to pass through. Sometimes one gets to watch something special during this rather meditative occupation. A blue flash of light emerges from the filter when I fold it to place it in a tube for further processing.
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