Bottom trawling was conducted today on shallow depths close to the coast. Unfortunately, there were no big catches of gobies or hakes. The research vessel will therefore head offshore to deeper waters in the hope of larger catches for the marine biological experiments on board.

The research cruise with G.O.Sars in the Southern Ocean has come to an end. We were safely guided to the harbour in Walvis Bay by our navigators, together with the pilot onboard the boat “Flamingo”.

Vema seamount lies in the South Atlantic Ocean about 1,000 km west-north-west of Cape Town, at 31° 38' S., 8° 20' E. It was discovered by the research vessel Vema in 1959. The very shallow and steep seamount in the middle of nowhere was first studied for possible diamond resources.

On every trawl haul the scientists on board "G.O. Sars" get excited: What is in the nets? Enormous sized jellyfish? Salps? Strange fish? Krill? We hope for krill; living krill! Some have to live, because we want to do growth rate experiments with them.

The whale observations in the Southern Ocean have been conducted on the bridge of G.O. Sars, which is an excellent platform for spotting different species of marine mammals and seabirds along our cruise track from Cape Town down to the Antarctic continent. We have so far documented eight different species, including sperm whale, minke whale, humpback whale and fin whale.

At 41°S in the southern Atlantic Ocean, on our way to Walvis Bay, Namibia, after weeks in waters with temperatures close to 0°C, we measured surface temperatures of 16°C. The distribution area of our main study organism, the Antarctic krill, is now left behind and we have started analysing our collected data.

It has been estimated that more than 50% of the species on earth are parasites, exploiting the remaining species acting as hosts. Parasites may interfere with almost any aspects of their host’s life; familiar to most are the effects on appetite and growth caused by tapeworms, but parasites may also cause disease and death (epidemics).

Acoustic surveys of krill, fish, and other marine animals requires a fundamental understanding of how sound transmitted from a transducer mounted on the ship's hull is reflected back from a target organism as it goes about living at some subsurface depth below the sea surface. The intensity of the returning echo is a measure of the target strength of a given individual at a particular sound frequency. But what determines an individual’s target strength?

After three weeks at sea the Bouvet Island raises in front of us with its magnificent glaciers and mountains during a moment of clear sky and sunshine. Some minutes later the Island is again covered in mist. At a research station close to the island the sampled Antarctic krill, Euphausia superba were extraordinary large (up to 6 cm long) with a greenish colour to stomach and gut. The krill feed on microalgae important in the Southern Ocean, and we found remnants of various diatoms when we investigated the gut content under a microscope.

The Bouvet Island is the southernmost island on the Mid-Atlantic Ridge. It is situated in the middle of the Southern Ocean between Cape the Good Hope in South Africa and the Antarctic continent, at 54° 25’S and 3° 21’E. This small and uninhabited volcanic island measures 7 x 10 km, reaches 780m above sea level and 94 % of the surface is covered by a glacier.

Scientists and crew on board “G.O. Sars” waited, with great expectations, for biological specimens collected from around 1200 meters deep. This was the first time that we used the larger fishing trawl, with an opening diameter of 520 m, to sample larger and deeper living organisms from the mesopelagic zone of the Southern Ocean. More than 2000 meters of wire was necessary to bring the trawl down to the deep.

Antarctica is well known and feared for the changing weather conditions, strong winds and high waves. On the other hand, it is important that analysis based on genetic variation in proteins (allozymes), are conducted with as fresh samples as possible. This means high quality results of the protein analysis, while samples for DNA studies are normally preserved in ethanol and can be analysed later in a molecular genetic laboratory.

In 2006 nine so-called “PIES” – Pressure sensor equipped Inverted Echo Sounders - were deployed to measure changes in surface level and transport of water mass of the Antarctic Circumpolar Current: Yesterday, we arrived at the first of three positions where a new PIES with fresh batteries was deployed. This PIES will measure water pressure at the ocean floor during the next 2 to 4 years.

G.O Sars is equipped with six hull mounted echo sounders and one sonar which continuously emit sound waves. The returned echo signals are compared to acoustic models in order to identify krill and other species as well as to determine their size.

The research team on the Bouvet Island had lost their internet connection and needed a data file to restore it. The file was downloaded on the G.O. Sars, burned on a CD and delivered on the beach with an ice-cream cake, chocolates and some other snacks. 

We can spot the Bouvet Island in the distance. This small island was made Norwegian territory in 1930. We are here to research the distribution of fish and plankton. This is the first time Norway surveys the marine resources in the area.

The daily freshwater consumption on G.O. Sars is about 10 000 liters, or 10 cubic meters. The vessel has two tanks that hold 184 cubic meters combined. That will last us almost three weeks. At the moment there is no need to restrict consumption. 

We have skipped another few research stations due to the bad weather and we are now slowly making our way south. During this research cruise we have encountered several species not found in the waters where we normally do research. Merete Kvalsund and Jaime Alvarez have compiled a selection of the fish species caught so far:

It is Sunday morning and hardly anybody is up. We had a storm this morning which prevented all research activities. Even if the wind has dropped now the ship still rolls a lot. 

Time flies even faster here in the Antarctic Ocean than it does at home. The weather has been great. But even in the middle of summer the temperature here is only 3 degrees centigrade. Comparatively, the summer in Bergen last year was fabulous. 

It took Einar Loshamn (26) only a few seconds to decide when he was presented with the opportunity to collect data for his Master’s thesis in marine biology on a research cruise in the Antarctic Ocean. He has now collected data for a few days around South Georgia and posts this report:

Acoustic measurements of krill are usually done by using echo sounders mounted on moving ships. Mounting echo sounders on platforms which are submerged and subsequently left alone for a day or two, however, yields a better understanding of the natural behavior of krill and other creatures found in the Antarctic waters.
 

Estimates of the krill stock size vary significantly from 37 million metric tonnes to over 150 million tonnes. Georg Skaret photographs the krill and combines this with echo sounder data in order to get a better understanding of just how much krill there is.
 

- Dramatic changes seem to happen in the Antarctic environment, which will not be without serious consequences for the ecosystem. A strong international effort to study at least parts of this vast ocean is needed, Volker Siegel argues. The German researcher at the fish research institute ISF in Hamburg has been on 20 research cruises in Antarctic areas over the last 30 years. On this cruise he is participating on the AKES project. Volker has written this cruise journal:

Calibrations are finished and we have left the penguins, seals and rusted old whaling stations of South Georgia behind. We started searching for krill and found them so fast the researchers hardly got to finish their meeting preparing how to handle the catch. 

Roger Munns and Nick Guy are two cameramen whom the BBC has sent along on our research cruise to the Antarctic to film krill, preferably large schools of them being attacked by predators. Not an easy assignment.

The various eco sounders must be correctly calibrated before we head for the open ocean to do acoustic measurements of krill and mackerel ice fish. We have spent a few days calibrating in one of the many South Georgia’s fjords. Today we also had guests for lunch.

Having finished the final core sampling in one of South Georgia’s many fjords, we went ashore at Grytviken. This was a Norwegian whaling station from 1904 to the mid 1960s. Today it is home to a British research station, penguins and seals. 

The core sampler surfaces from 3000 meters depth with the see-trough plastic tubes about half filled with bottom samples. Stig Monsen and Øyvind Paasche are pleased with the samples which are sealed and stored. Content analysis will tell us a lot about climate variability 15 000 years ago.

The crew on G.O. Sars has rigged the trawl and tested it. The small catch that this resulted in provided the biologists on board with an opportunity to take a closer look at the various marine species found in this area and made it possible to test out the identification procedures.
 

After refuelling from a tanker anchored up in the fjord just outside Stanley on the Falkland Islands it was time for a safety exercise. The alarm sounded and everybody gathered just behind the bridge on the fifth deck. There we were instructed to don survival suits and enter the lifeboat.
 

It’s been a week since we left home and we are getting used to the blue sky and the sunshine. We left Montevideo on January the 4th and we are approaching the Falkland Islands where we will refuel and refill freshwater. It will be a special experience to visit this island that received so much attention when Argentina invaded it in 1982.
 

The much anticipated research cruise with “G.O. Sars” to Antarctic waters has finally started.

The Norwegian Polar Institute was very pleased to be invited by the Institute of Marine Research (IMR) to join part for the Antarctic expedition with their research vessel G.O. Sars. It was soon decided that the Polar Institute should participate the cruise with bird observer.

The 26 February at 4 am the pelagic trawl, with five separate nets fishing from 0-750 m depth, entered the trawl deck on board G.O. Sars packed with gelatinous organisms, including species of salps. There were thousands of them in the nets.