Week 6 — 3-9 January 20083 January 2008Bram Feij, Imares
Introducing a top predator counter
In between a lot of research on board of the RV Polarstern which is focussed on very small animals like nematodes, amphipods and all kinds of (epi) benthic and planktonic life, there is the group of the Dutch Wageningen Imares Institute located on the island of Texel which is also working with animals up to 50 tonnes in weight. These are whales which roam across the Southern Oceans and the Lazarev Sea where the Polarstern is now finding its way through the pack-ice.
My name is Bram Feij, 37 years old and living on the island of Texel. But for about 2 months, together with Jan van Franeker, I count the top-predators which include birds, penguins, seals and whales. To be able to count them, I live for many hours a day (or in the polar summer night) in a very small cabin on top of the ship’s bridge roof with the best view you can get. With the specially developed SUIT (Surface and Under Ice Trawl) net which can fish under the ice-floes, our team consisting of 5 members tries to find out the relation between the amount of food available, the food-needs by top predators and the role of the sea-ice in the Antarctic region.
For me it is like a holiday. Well eh, actually it really is my holiday. I am a volunteer on this trip to complete the Wageningen Imares Team. Normally I work on another ship, much smaller than the big and strong Polarstern. It is owned by the Dutch Ministry of Agriculture, Nature and Foodquality and on board I work as a nautical officer, a fishery and nature inspector and, quite similar to the work on board RV Polarstern, collector of bird and wildlife data. The name of the ship is m.s. Phoca which is a family name for a lot of seals in the northern hemisphere.
A combination between studying Forestry and nature conservation and finishing the school for Seafarers in Rotterdam has led me into this position after doing all kinds of other sailing and forestry/nature conservation work. Besides the voluntary work I do right now, I am also volunteering for the Dutch lifeboat association KNRM on one of the lifeboats based on the island of Texel. This means a lot of water in my life but still, even in cold and bad weather sailing over the southern ocean and standing in my small cabin on the bridge-roof, I feel great to be out at sea. It sometimes can be boring and cold but at the end, I always get rewarded for being out there. Sometimes it is the stunning sight of a graceous Wandering Albatross besides me, the funny sight on a group of quarelling Adélie Penguins, a sleeping Weddell seal or an Antarcitic Minke whale breaking the surface in between the pack-ice. I am enyoing every bit of it!
4 January 2008Michael Schrodl, Zoological Museum Munich
Maud Rise
Is today yesterday or already tomorrow? Hard to tell sometimes. It is daytime, isn’t it? Anyway, some time in the evening the first box corer brought a nice piece of seafloor onto the deck. A quarter of a square meter of a sandy something garnished with a few brittle stars. Could be from anyplace, but isn’t: in front of us is the first seafloor sample from the plateau below the summit of Maud Rise, a solitary mound rising some 3,000 m from the Weddell abyssal plain. Still 2,000 m below the surface. An island in the vastness of the deep, so-to-speak. And possibly an oasis of life? The sand turns out to be a foraminiferan graveyard. Foraminiferans are single-celled animals with hard shells which can accumulate to thick sediment layers. And in it there are lots and lots of small bivalves and even gastropods. This is good news for the mollusc specialists who have not exactly been spoiled with an overabundance. Where there are many bivalves, sufficient nutrition must be available for filtering in the water column or the sediment. Our colleagues the oceanographers will explain to us that we are in the center of the Maud Rise gyre. Plankton and detritus could accumulate here.
Such thoughts, meandering while I turn over sand grains that are not even real sand, are interrupted instantly: the next quarter of a square meter is coming on deck. Waterproof clothes, rubber boots and hard hat on, a little exercise in the fresh air: filtering and washing of sediment with freezing cold sea water, transferring samples into containers, scrubbing the deck. Everything works like a machine, the team is well organised. It is neither bright nor dark, must be after midnight. Sorting skeletons yet again. This was much more exciting a few hours ago. But all animals have to be picked out of the sediment before they deteriorate. It is amazing in any case that the critters are still alive. They just came from a depth of 2000 m to the surface, where the pressure is just 1/200th as high.
The station monitor announces the big Agassiz trawl for 5 o’clock in the morning. Not worth going to sleep. Better keep up the caffeine level. At four a.m. the time has already come. A dozen large tubs are standing there for the awaited masses of mud. We expect long hours of washing until the very last sediment particle has been passed through a 0.5-mm sieve. Well, nothing of that kind happened: the cod end is hanging rather sluggishly from the huge steel frame. Upon opening, a few fish, sea urchins and some 17 kilos of sea cucumbers fall on the deck. But not just your normal sea cucumber! These ones are true monsters. These creatures, nearly 1 meter long and as thick as a seman’s upper arm, plough through the seabed with open mouths, digest what little biomass there is in the sediment and dispose of the rest at the other end. That’s how simple the life of an unspecific sediment eater is. Well, not quite, evil is looming everywhere. On our cucumbers there are parasitic snails, sucking while buried deeply in the skin. Most likely new species, caught red-handed while feasting on their host!
If only a few monoplacophorans would show up, they would make my day. These limpet-like animals, minute (only 1-2-millimeters) and extremely rare, are living fossils. If at all, I would find them in the fine-meshed net of Henri’s Rauschert Dredge, a rightout cute little steel sledge which was allowed to ride along and scrape the seafloor behind the trawl: bivalves, snails, brittle stars and myriads of protist shells. Sounds strangely familiar. Not a single little monoplac. The bivalve jar is overfilled, hands and tweezers work on remote control. I sort, therefore I am. Even without a sense of time or sleep. A little bit happy about the nice specimens. And a little bit sad because my darlings were again not present. Polarstern keeps steamimg on, and some 2000 m down a few tiny beings are smiling into the eternal darkness.
5 January 2008Victoria Wadley, Census of Antarctic Marine Life and Australian Antarctic Division
Good news travels fast
Yesterday I received an email with exciting news — Time Magazine had recognised Antarctic biodiversity research in its Top 10 scientific discoveries for 2007. At that moment, I was muddy and tired after working through the night with our team processing the animals from the Agassiz trawl. This news put a new perspective on the day!
The discovery was reported in a Nature paper on biodiversity and biogeography of the Southern Ocean deep sea published in May 2007 by a team of 21 biologists. Right now, four of them are here at sea on RV Polarstern: Angelika Brandt (lead author), Brigitte Ebbe (polychaetes), Saskia Brix (isopods and molecular biology) and Dorte Janussen (sponges). They come from the University of Hamburg and the Senckenberg Institute in Germany. Their team found over 700 new species of organisms, including isopod crustaceans, carnivorous sponges and giant sea spiders on the seafloor of the Weddell Sea off Antarctica, at bottom depths from 700 m to 6,000 m.
The email came from Fred Grassle, father of the international Census of Marine Life. He said “Dear Victoria, Angelika, and Brigitte, Best wishes for a very Happy Year! Your exploits have become famous. Congratulations, keep up the great work!”
On Polarstern, my job is the Education and Outreach part of the voyage, working with Brigitte Ebbe. I bring nearly 30 years’ experience as a seagoing biological oceanographer to the task. We work with the Census of Marine Life in the field projects CAML (Census of Antarctic Marine Life) and CeDAMar (Census of the Diversity of Abyssal Marine Life). As a top priority, we drafted a press release about the news, consulting with the voyage leader Uli Bathmann and waiting until everyone was awake to make their finishing touches.
Last night, we reflected on the events of the day with a glass of red wine. Wow, the importance of discovering and accurately describing new species had become world news. Of course, the recognition by Time Magazine was wonderful. But what really thrilled us was that the importance of our biodiversity research in this diverse and beautiful ecosystem would become better known. The marine life of Antarctica’s seafloor is cradled in deep bottom water formed by melting ice; this is connected to all the other oceans by the Antarctic Circumpolar Current. What happens in Antarctica is of fundamental importance to the health of the oceans on our planet.
6 January 2008Judith Hauck, Bjerknes Centre for Climate Research, Bergen Upside down and inside out
If it weren’t for the fact that the Christmas tree has disappeared from the messroom, we would not notice at all that today is Epiphany. The CTD just came back to the surface with 23 bottles of newly collected seawater (actually, it was supposed to be 24 bottles, but now and again number 20 is somewhat less than reliable...). The water samples will keep Craig busy for about nine hours. He and I take turns at the instruments to measure CO2 and alkalinity (a parameter to describe the difference between negative and positive ions in seawater). I will not have to worry about the new samples because my shift is from midnight until noon, so now it’s my time off!
Typically we get new water samples three or four times a day, and as the water does not only contain gases and ions but also plankton which will use the CO2 for photosynthesis, the samples have to be stored cold and dark and measured within 24 hours. Therefore the instruments — and we — are running 24 hours a day... The holiday may have passed without us noticing it, but the next few days are likely to be really quiet for us. In the ‘normal’ world, the holidays are over, and regular work is starting again, while we finished work on our transect at an instant’s notice to go on an icebreaking mission. The Naja Arctica, the container ship holding most of the parts for the Neumayer III station, has been stuck in the ice for weeks, and we are going to free her from her prison.
For us, it means (aside from getting up for dinner for a change) that we will have time to look at the data collected so far and draw first conclusions. We will compare the measured CO2 values with those from previous years to detect anthropogenic CO2. From the CO2 and alkalinity values one can also calculate the entire marine carbonate system, including the pH of the seawater. The more CO2 the ocean absorbs, the more acidic the water becomes — a catastrophe for organisms with calcareous shells or skeletons, such as algae, but also bivalves, snails, corals etc. because their tests will dissolve in water that is too acidic. The average pH of surface water before the industrial revolution was 8.2. Today it is about 8.1, and it will continue to fall.
7 January 2008Volker Strass, Alfred Wegener InstituteA game of Boccia Finally the conditions are perfect for a game of Boccia! There is only a soft breeze, and we are in open water surrounded by a broad band of sea ice which keeps the swell from the open ocean from hitting us. The Polarstern is fairly stable in the water, so we started our boccia game at 6 a.m.
We play with four copper balls, the smallest of which is about as big as a hazelnut, and the largest the size of a tomato. Now in our game the goal is not to bring the balls together as closely as possible, but rather to get them into a target area under the ship. This area, 15 m under the keel at 11 m below the surface, 30 m behind the bow of the 120-m-long ship and exactly in the middle of the 25-m-wide Polarstern, has a diameter of 1.5 m.
Our balls are very special in that they have clearly defined acoustic properties. That means, they reflect and disperse sound of a given frequency in a defined way. The target area under the keel of Polarstern is positioned in the sound cone of the zooplankton echosounder. Rather than measuring the time between the pulse of sound and the strongest echo and thereby calculating the distance to the seafloor at a known travelling speed of soundwaves like a regular echosounder, the plankton echosounder measures the strength of the echos returning from different distances. In principle it is possible to determine how many sound dispersing objects there are in a certain water layer respectively how much the objects are dispersing sound waves. In order to calibrate the zooplankton echosounder, the balls must be kept in the sound cone. Calibration tells you something about the particular properties of an instrument, which is necessary because each instrument is different regarding not only the transformation of electrical energy into sound, but also the transformation of the intensity of the echo into the actual signal. And the four different balls are used because the zooplankton echosounder works with four different frequencies. Such balls with well-defined acoustic properties are used for calibration on research vessels worldwide to make comparisons of acoustic measurements from different vessels possible.
The calibration process requires, aside from technical understanding, a certain athletic competitiveness. The balls have to be guided into the target area by a system of lines and ropes. Gallows are fastened to the bordwall at approximately equal distances. The points are located on the ship according to drawings, two on the starbord side and one on the port side. Ropes are running through the gallows straight into the water, held taught by weights. Rings are fastened to the ropes one meter apart, and through these rings a fishing line is running. The fishing lines are tied together on the free ends, and exactly at this knot the copper ball is sitting. As we do not have divers on board to tie the knot under water, this has to happen on deck before the ball is put into the water. The first challenge is to put a loop of line into the water at the bow and then pull it astern underneath the ship’s hull. This exercise has to be repeated for each ball. Once the ball is in the sound cone, one can see on a computer screen how the ball is moved through the cone by paying out line in 10-cm steps on one side and hauling it in on the other. For a solid calibration the ball must be guided into each of the four sectors of the sound cone and exposed to sound with different parameters ranges of the zooplankton echosounder.
The zooplankton echosounder helps to obtain important scientific data on the distribution of planktic animals down to 600 m at high resolution, temporally as well as vertically and, during travel, horizontally. The use of four different frequencies allows to distinguish among four size classes of zooplankton and consequently helps to extrapolate the species composition.
Data gained with the zooplankton echosounder form the base of the Lazarev Sea krill study (LAKRIS). They also contribute substantially to the IPY project SCACE (Synoptic Circum-Antarctic Climate-Processes and Ecosystem Study). As SCACE is linked closely with ANDEEP-SYSTCO (ANtarctic benthic DEEP-sea biodiversity: colonisation history and recent community patterns — SYSTem COupling) to find out more about the flux of biogenic particles and therefore carbon flux to the seafloor, ANDEEP-SYSTCO can utilise measurements from the zooplankton echosounder as well.
It is not one team of scientists playing against the other in this game of Boccia. The common enemy is movements of the ship relative to the water under the ship, which can not be avoided completely. All scientists are playing together, hand in hand with the bridge and crew. They have to. The current game will not be over before tomorrow morning.
8 January 2008Brigitte Ebbe, SenckenbergTempora mutantur...
My alarm clock rings at seven, like almost every morning, and before I get up I try to guess whether we are standing or travelling, as I do almost every morning. Did the krill people finish the calibration of the echosounder? Yesterday afternoon it still seemed like a very big task... But no, a glimpse out of the window tells me that we are quietly sailing through the polynya which surrounds the ship as calm as a little mill pond. The shelf ice edge is shimmering magically in the distance even under the overcast sky.
During the morning preparations start to accommodate the 33 German construction workers waiting to start the building of the new station. They have been waiting on the south African station SANAE and on the south African ship SA Agulhas so far. Now we have to move together for short time. The mood on the ship changes, everybody smiles, but at faces unknown, we are not used to that any more. I suddenly realise how much of a family we have become during the last six weeks, no matter how much we differ in our working rhythms and personalities.
The plan for the evening was to continue a much loved tradition, the Belgian Night at the Zillertal. Our Belgian colleagues brought some samples of their famous beers for tasting. Will it still take place, will there be enough beer to share with the guests? Well, sure, some people say. No, it will be postponed, others point out. Henri, he is from Bruxelles, he must surely know. Will be postponed, he says. Ten minutes later in the Red Saloon the opinion is that it will take place after all. It is not until the evening seminar that this important question is answered unequivocally. The Belgian Night will take place this coming Saturday. We also hear more of the story about our guests. They spent some time at the nearby South African station Sanae and were going to be flown to Neumayer by South African helicopters, but the weather was not good enough for a flight over the ice. Polarstern came as fary at a short notice, and the workers were flown to the ship and will travel with us to the Neumayer station. The orcas, of course, knew all this beforehand, and as if to entertain our guests, they gave a stunning performance just before dinner.
9 January 2008Myriam Schüller, Ruhr University of BochumThe everyday life...
Besides all the spectacular events of any journey to the Antarctic, there is the everyday life of ‘normal’ working days even on a research vessel. As was already mentioned in previous logbook entries, I belong to the benthos team. Which means, I deal with animals restricted to the seafloor. To be more precise, I am a specialist for deep-sea bristleworms (relations of the lugworm), and I am also familiar with deep-sea isopods. When I talk about these animals to non-benthologists, my enthusiasm is seldomly shared by them. However, these two groups not only constitute more than 50% of all deep-sea organisms, but also show a dazzling variety of shapes and forms. A sound knowledge of these groups is therefore essential for deep-sea research.
While samples from the water column contain clean animals that are easy to sort, benthic samples are notorious for consisting of not much more than mud, at least at first glance. An untrained eye would not see anything special in the tonnes of mud our gear brings up into daylight. To us, on the other hand, this sediment is the door to the unfathomed world of the deep sea. Thousands of tiny organisms, no bigger than 1-5 mm, are hiding inside the mud. Between stations our everyday life therefore consists of washing this mud very carefully through fine meshed sieves, picking every single animal under a stereo microscope and assigning it to a large organims group. So far, we have sampled four stations, the last one about a week ago. Three of these stations are sorted until now, so we feel optimistic that we will have sorted two-thirds of our samples by the end of the expedition.
The remaining samples are fixed and stored cool to be sorted at the laboratories at home. Four people need about one to two weeks to sort one sample. Depending on the sediment type, this requires more or less patience (usually more), as ship movements also keep the sample under the stereo microscope moving, and resuspended mud particles make it difficult to see anything. In spite of, or maybe rather because of this strain, we always enjoy discovering ‘old friends’ (species that occur frequently and are already well-known). If somebody finds a totally unknown species, we all become outright enthusiastic. As the deep sea, and especially the deep Southern Ocean, is poorly investigated, the joyful exclamation "Wow, what on earth is this? I have never seen anything like this before!" is heard relatively often in our lab.
The caught animals help answer a great many scientific questions, by the way. Aside from the pure censusing, we can investigate their colonisation history, evolution and phylogenetic relationships. The focus of this expedition is the relation between atmosphere, water and deep-sea floor. It is quite remarkable how much life and scientific potential can be found in a handful of deep-sea mud.
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