Antarctica, a vast land remote from the other continents and still the least known of them all, provides a unique international laboratory for science. Despite the costs, a growing number of countries are supporting basic scientific research on the continent and in its surrounding seas. Our knowledge of life in this extreme environment, although limited, suggests that it is a key environment for many areas of science. Potential economic developments for food and minerals as well as increasing political complications might jeopardise the present scientific accord in the future. Now is the time to take stock: what do we know about Antarctic ecology? What are the threats and how can they be met? In this volume Antarctic scientists from six countries write about the Antarctic ecosystem.