Diversity and Ecological Roles of Prokaryotes in the Changing Antarctic Marine Environment

The Antarctic marine ecosystem is particularly vulnerable to climate change, with further exacerbation mainly deriving from the potential impacts of human activities at research stations. Anthropogenic changes in Antarctica pose a serious questioning about the ability of microbial communities to respond to environmental stresses in this extreme and fragile environment. Establishing the base-lines of Antarctic prokaryotic population composition and ecophysiological activities becomes essential to monitor the functioning of ecosystems and the effects of climate change. In this chapter, we present an overview of the prokaryotic communities in the Antarctic marine environment and the potential/current influence of climate change, mainly related to rising temperatures, on their composition and activities. A focus will be done on the role of prokaryotes in the changing polar carbon cycle in seawater, sea-ice and sediments.