Antarctic Marine Explorers Reveal First Hints of Biological Change After Collapse of Polar Ice Shelves

10-week Voyage Yields Likely New Species, Insights into Polar Ecology; Intrigued Scientists Find: Herds of Sea Cucumbers on the Move, Fields of Colonizing Sea Squirts, Whales Approach Coast; Deep-Sea Species at Unusually Shallow Depths on Uncapped Seabed.

 

Covered by ice for thousands of years, a 10,000 square km portion of the Antarctic seabed is one of Earth¹s most pristine marine ecosystems that has become suddenly accessible to exploration by the collapse of the Larsen A and B ice shelves, 12 and five years ago respectively. Now it has yielded secrets to some 52 marine explorers who accomplished the seabed¹s first comprehensive biological survey during a 10-week expedition aboard the German research vessel Polarstern.

With sophisticated sampling and observation gear, including a camera-equipped, remotely-operated vehicle, experts on the Polarstern have returned with revealing photography of life on a seabed uncapped by the disintegration of Larsen A and B. The expedition uncovered a wealth of new insights and brilliant images of unfamiliar creatures among an estimated 1,000 species collected, several of which may prove new to science.

 

The Polarstern’s mission included charting the environmental impact of history¹s largest known ice shelf collapses. Polarstern’s team set out to find what indigenous forms of marine life existed under Larsen A and B, and what new organisms now are opportunistically moving in.

Polarstern Discoveries and Insights
Larsen zone seafloor sediments were extremely varied, ranging from bedrock to pure mud. As a result, animals living on the sediment were highly varied as well, though far less abundant in the Larsen A and B areas, perhaps only 1% animal abundance compared to sea beds in the eastern part of the Weddell Sea.

 

In the relatively shallow waters of the Larsen zone, scientists were intrigued to find abundant deep sea lilies (members of a group called crinoids) and their relatives, sea cucumbers and sea urchins.

These species are more commonly found around 2,000 metres or so, able to adapt to life where resources far more scarce, conditions similar to those under an ice shelf.

Apparent newcomers found colonizing the Larsen zone include fast-growing, gelatinous sea squirts. The scientists found dense patches of sea squirts and say they were likely able to colonize the Larsen B area only after ice shelf broke in 2002.

Very slow-growing animals called glass sponges were discovered, with greatest densities in the Larsen A area, where life forms have had seven more years to re-colonize than Larsen B. The high number of juvenile forms of glass sponges observed probably indicates shifting species composition and abundance in the past 12 years.

 

New species discovered
- 15 potential new amphipod (shrimp-like) species from 400 specimens. The star attraction is one of Antarctica¹s biggest-ever amphipod crustaceans ¬ nearly 10 cm long, larger than many similar species found in temperate climates; and
- Four presumed new species of cnidarians (organisms related to coral, jelly fish and sea anemones). One is a potentially new sea anemone, co-existing on the back of a snail ¬ their symbiotic relationship providing locomotion for one and protection for the other.

 

In all, some 700 and 8,000 nautical miles were dedicated by the Polarstern and its helicopter crews respectively to recording the presence and behaviours of marine mammals, which included Minke whales close to the pack ice edge and very rare beaked whale species near Elephant Island.

‘It was surprising how fast such a new habitat was used and colonized by Minke whales in considerable densities,’ says specialist Dr. Meike Scheidat of Germany. ‘They indicate that the ecosystem in the water column changed considerably.’

Polarstern's 52 scientific participants were from these 14 countries: Germany, France, Belgium, United Kingdom, Spain, Italy, Czech Republic, Ukraine, Russian Federation, Canada, United States, Chile, Mexico and Denmark.

Partners:
Alfred Wegener Institute for Polar and Marine Research (AWI) AWI conducts research in the Arctic, Antarctic and in oceans of mid and high latitudes. It coordinates polar research in Germany and provides important infrastructure, such as the research icebreaker Polarstern and stations in the Arctic and Antarctic, for international science organisations. The AWI is one of 15 research centres of the 'Helmholtz-Gemeinschaft' (Helmholtz Association), the largest scientific organisation in Germany. See: www.awi.de/en

The Census of Marine Life (CoML)
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Census of Antarctic Marine Life (CAML)
CAML (like its sister program, ArcOD -- Arctic Ocean Biodiversity, http://www.sfos.uaf.edu/research/arcdiv/index.html) is a project of the global Census of Marine Life. CAML is investigating the distribution and abundance of Antarctica's vast marine biodiversity to develop a benchmark for the benefit of humankind. As one of the main International Polar Year-endorsed initiatives, CAML will be the biggest Antarctic marine science program ever undertaken, involving 24 biodiversity projects investigating life from microbes to whales. See: www.caml.aq

International Polar Foundation (IPF)
The International Polar Foundation communicates and educates on Polar research as a way to understand key environmental and climate mechanisms. The IPF also promotes innovative and multifaceted responses to the complex challenges raised by the need for action on sustainable development. IPF's www.sciencepoles.org has been selected by the IPY International Programme Office as the Internet reference for general polar research news and information. See also www.polarfoundation.org and www.educapoles.org.

The Cousteau Society (TCS)
Created by Jacques-Yves Cousteau in 1973, the international Society focuses, among other goals, on the equilibrium between humanity and nature on the world¹s oceans. TCS has three decades of international experience documenting and communicating the value of natural resources, including within the polar realms. TCS has a strong legacy of preserving Antarctica, which includes Captain Cousteau¹s worldwide petition that helped keep Antarctica as a ³natural reserve, land of science and peace². See: www.cousteau.org

The Polar Embassy
The Polar Embassy is an official International Polar Year education and outreach project linking scientific knowledge to the public at large. It focuses on topics related to polar areas, sustainable development and global climate change, and their links ‘From Local to Polar’.

The expedition forms part of the Census of Antarctic Marine Life (www.caml.aq), which has 13 upcoming voyages scheduled during International Polar Year, to be launched in Paris March 1. A project of the global Census of Marine Life (www.coml.org) collaboration, CAML is responsible for the synthesis of taxonomic data and supports the efforts of national programs the world over.