Response of marine and terrestrial ecosystems to climate changes in Arctic ? links between physical environment, biodiversity of zooplankton and seabird population

The main objective of the project is to estimate the impact of climate warming on Arctic zooplankton communities (Calanus), little auks (Alle alle) and their physical environment. We will study the interactions between water masses, marine and terrestrial ecosystems by using direct and innovative remote sensing methods. Our goal is to obtain data on
water circulation, heat and salt transport by the West Spitsbergen Current, fjords hydrology and fjords' deep sea exchanges, optical parameters concerning the phyto-and zooplankton living conditions, plankton communities and local Little auk population parameters, breeding and feeding ecology and behaviour. Investigations will be carried out in three Spitsbergen fjords representing different climatic regimes and biota: 1) Hornsund influenced by Arctic Sørkapp Current and Atlantic West Spitsbergen Current with large local Little auk breeding population; 2) Isfjorden and Kongsfjorden with predominating influence
of Atlantic water masses and with small scattered Little auk colonies; 3) Magdalenefjorden, where large local breeding population is maintained, presumably due to short distance to sea ice edge. Climate changes in the Arctic will influence ocean circulation and the hydrologic regime, which will consequently lead to a restructuring of zooplankton communities between cold Arctic waters, with a dominance of large zooplankton species, and Atlantic waters in which small species predominate. Little auks breeding in Spitsbergen, feed mainly on the large copepod Calanus glacialis, so tend to restrict their foraging activity to Arctic Water and avoid Atlantic Water, which contains mainly smaller copepod, Calanus finmarchicus. Parallel to the changes in zooplankton community structure we expect a change in vital population dynamical rates of little auks. In the areas where the little auks can reliably forage, the reproductive output, corrected for predation, should be higher than in colonies where little auks have to either fly far or utilize scattered patches of large zooplankton.