Abstract: Identifying the basic habitat requirements of Antarctic predators is fundamental to understanding how they will respond to the human-induced challenges of commercial fisheries and climate change. This understanding can only be achieved if the underlying linkages to physical processes are related to animal movements. As part of the international Retrospective Analysis of Antarctic Tracking Data (RAATD) organized by the SCAR Expert Group of Birds and Marine Mammals, this research will collate and synthesize tracking data from crabeater seals, Lobodon carcinophagus, and Weddell seals, Leptonychotes weddelli. These data will be combined with all available data from the Southern Ocean that has been collected by researchers from Norway, United Kingdom, Germany, Australia and the USA. These data will be analyzed using a common analytical approach and synthesized into a synoptic view of these two species across the Southern Ocean. The diving and movement patterns will be examined for each species. As well, the total home range and core habitat utilization patterns for each species and region will be determined. This study will develop global habitat maps for each species based on physical and biological attributes of their 'hot-spots' and then overlay all the species specific maps to identify multi-species areas of ecological significance. Broader impacts include support and training for a postdoctoral scholar, the production of a publicly available database and the participation in an international data synthesis effort.