ABSTRACT
Antarctic ecosystems are globally significant. This chapter reflects on their spatial ecology, historical impacts, future prognoses and challenges for conservation, rational utilisation and science. It shows that the Southern Ocean comprises many interacting food webs. The “phytoplankton-Antarctic krill-whale” food chain is dominant in the Atlantic sector and northern Antarctic Peninsula. Yet, the food webs of the other similarly productive areas in the Antarctic and Subantarctic Zones have a mix of energy pathways, including those based on Antarctic krill, copepods and salps. Importantly, a high-latitude polar food web is found on the continental shelf around Antarctica and is dominated by a coupled benthic-pelagic food web. The key threats to these systems are climate change and, potentially, an expanding krill fishery. This chapter promotes three pillars for an international, sustained, “end-to-end”, circum-polar ecosystem program to rapidly advance a much-needed scientific base for decision-making, including a coordinated field observation program with studies to elucidate primary ecological processes, a virtual ecosystem laboratory and ecosystem assessments. While climate change needs to be curbed through global action, the existing caps on krill fisheries provide an opportunity for Antarctic nations to resolve the outstanding issues for these fisheries, before they are allowed to expand further. In addition, these fishery caps provide an opportunity to determine limits to harvesting prey species and spatial management strategies for promoting resilience of these ecosystems, such as conserving species at risk from climate change and protecting climate refugia and climate-sensitive areas.
