9816616 Trivelpiece Long-term seabird research conducted at Admiralty Bay, which is located on King George Island in the Antarctic Peninsula region, has documented annual variability in the life history parameters of the breeding biology and ecology of the Adelie, gentoo and chinstrap penguins. Twenty-year records acquired on these species, including survival and recruitment, population size and breeding success, and diets and foraging ecology have enabled scientists to test key hypotheses regarding the linkage between these predator parameters and variability in the Antarctic marine ecosystem. This project will focus on understanding the linkages between the physical environment and the population biology of penguins, in particular, sea ice coverage and its impact on krill availability as a food source for penguins. Krill is a key food web species in the Antarctic oceans and accounts for nearly one hundred percent of the prey eaten by dominant predators such as baleen whales, seals and penguins. Analysis of long-term data sets has suggested that years of heavy winter sea ice favor krill recruitment, as larval krill find refuge and food in the sea ice habitat. It has also been observed that years of heavy sea ice favor Adelie penguin recruitment and not that of chinstrap penguins. Aspects of the work include analysis of diet samples, shipboard krill sampling, survival and recruitment studies of penguins, satellite tracking of penguins during the breeding season, and analysis of satellite sea ice images. Penguins are the key species used to monitor the impact of commercial fisheries activities in the region, so this study will provide useful information to the Convention for the Conservation of Antarctic Marine Living Resources, which is the part of the Antarctic Treaty System which focuses on fisheries management.