Microbial communities within sea ice are presumed to be a major carbon source for the pelagic ecosystem covered by ice. Also, the ice-water interface constitutes an important habitat for many organisms, including e.g. Antarctic krill and polar cod as key species. Highest densities of top predators are strongly associated with sea ice where primary production measurements suggest low productivity of the water column underneath. Climate warming can cause changes in extent, thickness and seasonal persistence of sea ice and can therefore have consequences for ecosystem functioning. Understanding sea ice food webs can help the development of policy for conservation and fishery, considering future changes.
To investigate the importance of sea ice in the life of species, biological sampling at the under-ice and open water surface is done with the worldwide unique Surface and Under Ice Trawl (SUIT), which was hindered in the past by the inaccessibility of the sea ice underside. In the research, the diet of sampled organisms and energy flow between trophic levels are, for example, analysed.
Abundance, biomass and distribution of trophic key species, such as Antarctic krill, in the under-ice habitat are quantified, and the importance of sea-ice derived carbon sources is estimated. Also, the effect of sea ice on community structure is investigated.