Seabirds as monitors of upper-ocean thermal structure. King penguins at the Antarctic polar front, east of Kerguelen sector

The main objective of this work was to assess the potential of diving birds to monitor the hydrographic features near the Antarctic polar front. We co mpared the temperature/depth profiles recorded by instrumented King penguin s Aptenodytes patagonicus at Kerguelen Islands (South Indian Ocean) with th e oceanographic and remote sensing (satellite) data available for the same area during the same season. The birds were equipped with time/depth/temper ature recorders or Argos transmitters. In addition, two birds were instrume nted (of which one successfully) both with a time/depth/temperature recorde r and an Argos transmitter. King penguins foraged as far as 400 km from the coast, in water masses with a vertical temperature structure characteristi c of the region just south of the polar front. The temperature/depth profil es recorded throughout the dives (up to 270 m) revealed a pronounced thermo cline. A three-dimensional distribution of water temperature was reconstruc ted. Comparison with previous hydrographic data shows a high correlation. I nstrumented predators may therefore usefully and cheaply complement the dat abase provided by conventional hydrographic surveys and remote sensing, esp ecially in distant and rough areas such as the Southern Ocean. (C) 2000 Aca demie des sciences/Editions scientifiques et medicales Elsevier SAS.