LARISSA - LARsen Ice Shelf System, Antarctica, a NSF-funded project.

LARISSA - LARsen Ice Shelf System, Antarctica, a NSF-funded project.
We are conducting an integrated, multi-disciplinary field program to address the rapid and fundamental changes occurring in the Antarctic Peninsula region as a consequence of the abrupt collapse of the Larsen B Ice Shelf in the fall of 2002. A profound transformation in ecosystem structure and function is occurring in coastal waters of the western Weddell Sea. This transformation appears to be yielding a redistribution of energy flow between chemoautotrophic and photosynthetic production, and to be causing the rapid demise of the extraordinary seep ecosystem discovered beneath the ice shelf, providing an ideal opportunity to test fundamental paradigms in ecosystem evolution.

Thursday, January 21, 2010

13 January - This morning saw us progress further through the Gerlache Strait and into a glacial fjord named Flandres Bay. Efforts were made by all involved to ready the helicopters for flight and prepare equipment and supplies for the glaciology field teams. However unfortunately, the weather closed in before flying could start and consequently, both aircraft had to be grounded until the forecast improved. All onboard the ship had their fingers crossed for better weather soon.

Members of the biology team and oceanographic scientists instead busied themselves with the deployment and sampling of the CTD (a device which profiles the conductivity, temperature and depth at several intervals throughout the water column and which collects water samples that will be filtered and analyzed for phytoplankton, productivity and nutrients) at the head of Flandres Bay. We hope to deploy this device multiple times whilst in the bay, and will use data collected from each cast to build a comprehensive picture of what the water column looks like oceanographically and biologically.

Work on and the processing of the whale bone lander, recovered on 8th January off Vega Island was also concluded today. This was a relief for us and for the majority of the people onboard as whale bones are notoriously foul smelling (they produce a rotten egg smell common in anoxic marine environments and processes of decay), and this meant the bones could be packaged up and stored frozen before being deployed again later in our cruise schedule. Several species of worm, including the bone eating worm Osedax sp, were identified on several of the whale vertebrae. Further work will be undertaken on these specimens once we return to the lab in Hawaii, including morphological and molecular taxonomy to evaluate the evolutionary relationships of these worms.

12 January - As the sun rose on the morning of the 12th we continued our journey into open ocean, out of and away from the fast ice that had hampered our progress on the east side of the Peninsula, and bound for the west. From here, the two helicopters we have onboard will transport teams of glaciologists to sites on the Peninsula, where rock geology will be described, ice characteristics measured and the installation of field stations will occur, allowing for long term monitoring of glacial features.

As one of few people who have been lucky enough to visit Antarctica and spend time here working, I (Laura) can honestly say you never tire of the sights and sounds this incredible landscape has to offer. Our journey to the west side of the Peninsula was no exception. I am glad to say our passage was both smooth (for those prone to seasickness amongst us) and idyllic, and provided yet another backdrop of beautiful scenery, during which we were treated to sights of snow-capped mountains, blue open-ocean and floating masses of ice. We made steady progress over the morning passing through the Antarctic Sound, along the coast, and down through the Bransfield Strait into the Gerlache Strait. This area is also renowned for whale-spotting and sure enough several sightings of both Minke whale and Humpback whale were made today close to the ship. These majestic animals are common in these waters, transiting, feeding and using the area as a mating ground. All aboard the ship were happy and excited to welcome our new visitors and were equally anxious for them to stay around long enough to make the most of an amazing photo opportunity.

This side of the Peninsula is characterized by an array of glacial fjord systems and it is from these sheltered inlets that we intend to monitor the weather and co-ordinate helicopter missions when conditions are suitable for flying. Glacial fjords are unique environments influenced greatly by processes of sedimentation, water circulation and glacier retreat which
vary along the length of the fjord system. Consequently, the marine animals living on the sea floor of these areas are of biological interest to scientists. Therefore, in an effort to make the most of our new location and take advantage of a unique opportunity to sample the animals in these fjordic systems the biology team intend to photograph, survey and document
the animals living on the seabed. This will be done using an underwater ‘yoyo’ camera system- a camera which is lowered to the seafloor, and allowed to contact the seabed at which point a contact switch is triggered and a picture is taken. The camera is then brought off the sea bed a couple of meters, whilst the ship moves slowly a long a transect, and lowered again in a ‘yoyo’ like motion until a series of pictures are taken. We will also use a remote operated vehicle (ROV)- a robot on a cable which is piloted by an operator onboard the ship and can be flown over large areas of the seabed, photographing and collecting samples. Fellow collaborators from Ghent University, Belgium are the contingent aboard the ship responsible for the maintenance and operation of the ROV- otherwise affectionately known as ‘Suzee’. Everyone is excited to see Suzee do her first dive into the ocean. Many weird and wonderful creatures can be caught on camera by these devices and certainly on first time viewing you could be forgiven for believing they were pictures from the moon!

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