An evaluation of the risks associated with the highly productive but sensitive aquatic systems of Antarctica

Aquatic ecosystems (lakes and ponds) scattered throughout continental Antarctica and the
surrounding sea ice provide an extraordinary and tractable opportunity to examine how microbial
communities change and thrive under extreme (and variable) conditions. Many of these systems are
naturally isolated from one another and show striking physiochemical heterogeneity coupled with
steep vertical gradients and stratification of pH and conductivity. The chemical evolution of the water
column in these systems are largely controlled by the relative rates of water supply (with mineral
inputs) verses evaporation. They provide a unique laboratory to investigate the interactions between
the physical, chemical and biological components of a range of environments. This study will utilise
knowledge gained from previous expeditions sampling these systems to expand
what is known about their biodiversity and community structure. Through mesocosm experiments we
also hope to provide quantitative experiments to evaluate the risks posed by intra-continental
contamination (as outlined in the Biosecurity New Zealand/Antarctica New Zealand risk assessment
document) and to develop a model for impacts recently predicted for the region with global climate
change.