Huge areas of sea floor (around 3,250 km²) have been freed up by the collapse 4 years ago of the Larsen B platform along the Antarctic Peninsula -- leaving a blank spot on Antarctic maps. Polarstern, the research flagship of the Alfred Wegener Institute for Polar and Marine Research, will shortly conduct there the first major biological research, studying living communities, from microbes to whales, including bottom fish and squids.
Some 25 different research projects will be undertaken by 47 scientists, encompassing disciplines as diverse as benthology, planktonology, taxonomy, ecology, physiology, biogeochemistry, genetics, bathymetry, etc.
The first part of the expedition will focus on biological investigations on fish stocks as a contribution to the Convention on the Conservation of Antarctic Marine Living Resources (CCAMLR, http://www.ccamlr.org), following a dozen similar surveys since 1976. Researchers will monitor previously fished areas located in the western part of the Antarctic Peninsula to determine the state of stock recovery.
When Antarctic glaciers reach the coast of the continent, they begin to float and become ice shelves, from which icebergs are then calved. Since 1974, a total of 13,500 km2 of ice shelves have disintegrated in the Antarctic Peninsula, a phenomenon linked to the regional temperature rise of more than 2°C in these past 50 years. An increasing number of scientists worry that similar break-ups in other areas could lead to increases in ice flow and cause sea level to rise dramatically. The final collapse of the Larsen B platform in February 2002 is the latest and the biggest of these catastrophic events tentatively related to global warming, freeing an additional 3,250 km2 of sea bottom of an ice cover that has been estimated to be there for at least 5,000 years.
Meanwhile, the vanishing ice allowing vegetal and animal plankton to reinvade and thrive in these areas offers a perfect opportunity to study the evolution of bottom animal communities depending on this plankton. Sampling with various trawls, grabs and traps and the use of a remote operated vehicle with a video camera will allow the description of new species within this near-pristine environment. A dozen scientific studies will look into groups as different as microbes, sponges, crustaceans, octopuses, starfish and whales, from the grounding line to the open sea areas, and will furthermore give the best benchmark of the early stages of colonization. These studies could become a reference for other parts of Antarctica where such disintegration of ice shelves is already expected on how climate-induced shifts in biodiversity will change in ecosystems structured largely by ice.
The expedition will also lead the first biological studies of a recently discovered cold-vent ecosystem in the same Larsen area, the first of its kind known in Antarctica. Uncovered in 2005 by an American geoscience research team, this 8 km zone harbors mounds spewing out fluid and mud particles, as well as clusters of large clams. These mollusks and their associated fauna probably depend on chemical energy from the Earth, rather than one driven by photosynthesis from the sun or from hot emissions rising from inside the planet.
With 47 scientists onboard from more than a dozen different nationalities, the Polarstern expedition brings together an international network of research programs that will focus on the biological characteristics of this blank spot, from November 2006 to January 2007. One of the major contributors to the Census of Antarctic Marine Life (CAML), Polarstern's voyage will be a major event in the IPY, and open the way for further polar expeditions.
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