Climate-induced ice-shelf collaps: response of the Antarctic ecosystem

„Census of Antarctic Marine Life (CAML)“
„Evolution and Biodiversity in the Antarctic (EBA)“

Dr Julian Gutt

In the years 1995 and 2002 the Larsen A/B ice shelf collapsed at the Antarctic Peninsula, which had twice the size of Los Angeles. In the Antarctic life below such ice shelves is the norm rather than an exception but due to its inaccessibility this was so far maybe the least known marine habitat on earth. As a major contribution to the IPY-project „Census of Antarctic Marine Life“ this biological „white spot“ was ecologically investigated for the first time. The very poor fauna at the sea-floor includes filter feeders, which depended on food transported into this area over long distances from their place of origin in the open water (Fig. Gutt_1). This long distance may explain the similarity of the under-ice shelf fauna with that of the deep-sea. During the survey carried out with „Polarstern“ the international team of scientists also investigated the response of the ecosystem to the dramatic changes caused by the climate-induced ice-shelf disintegration in the course of “IPY-Evolution and Biodiversity in the Antarctic”. At the sea-floor the original fauna will be replaced firstly by fast growing pioneer species such as sea squirts (Fig. Gutt_2) and young sponges. In the open water krill and pelagic fish invaded already, and, as a consequence, also seals and whales. At intermediate time scales a very poor but unique ecosystem will be replaced by one that is more productive and rich at least in biomass (Fig. Gutt_3).

More about CAML...

 

  • Even large sponges grow under the ice-shelf
  • Sea squirts unusually fast in newly available habitats
  • ice-covered Antarctic areas can be very rich in species and biomass