Exploring South Africa’s southern frontier: A 20-year vision for polar research through the South African National Antarctic Programme

摘要

Antarctica, the sub-Antarctic islands and surrounding Southern Ocean are regarded as one of the planet’slast remaining wildernesses, ‘insulated from threat by [their] remoteness and protection under the AntarcticTreaty System’ 1 . Antarctica encompasses some of the coldest, windiest and driest habitats on earth. Withinthe Southern Ocean, sub-Antarctic islands are found between the Sub-Antarctic Front to the north and thePolar Front to the south. Lying in a transition zone between warmer subtropical and cooler Antarctic waters,these islands are important sentinels from which to study climate change. 2 A growing body of evidence 3,4now suggests that climatically driven changes in the latitudinal boundaries of these two fronts define theislands’ short- and long-term atmospheric and oceanic circulation patterns. Consequently, sub-Antarcticislands and their associated terrestrial and marine ecosystems offer ideal natural laboratories for studyingecosystem response to change. 5 For example, a recent study 6 indicates that the shift in the geographicalposition of the oceanic fronts has disrupted inshore marine ecosystems, with a possible impact on toppredators. Importantly, biotic responses are variable as indicated by different population trends of these toppredators. 7,8 When studied collectively, these variations in species’ demographic patterns point to complexspatial and temporal changes within the broader sub-Antarctic ecosystem, and invite further examination ofthe interplay between extrinsic and intrinsic drivers.