King penguins as indicators of climatic impact on Southern Indian ocean food webs

The objective is to study how some diving predators (penguins) may be used to assess the effects of the climatic variability at short and long term, on the pelagic food webs of the Southern Indian Ocean. The study is based on the deployment of data loggers (depth, sea water temperature, Argos transmitters or GPS) on breeding King penguins leaving the colony to forage at-sea. The database concerns 2 localities of the South Indian Ocean: Crozet and Kerguelen. The data have been obtained since 1992 at Crozet (17 years of quasi-continuous monitoring, except 1995 and 1999) and at Kerguelen since 1998, (11 years of data, continuous monitoring). Bio-logging data of at-sea trajectories, diving records, and in situ temperature profiles acquired each year on penguins are analysed along with remote-sensing data of sea surface temperature, sea-surface height anomalies, and primary production.

We have demonstrated a close link between the inter-year change in mesoscale frontal structure of the Indian Ocean (the Polar Front) and the King penguins foraging range and preferential depth. Our aim now is to determine what are the foraging responses in different modelized foraging habitats in relation to long-term climate changes.