This module examines the microbial processes that underpin our dependence on the marine environment for `services' such as climate modulation and nutrient regeneration. The module will cover the evolution, biodiversity and molecular ecology of bacteria, diatoms, coccolithophores and nitrogen fixers, and the physiology and distribution of zooplankton. Example ecosystems such as the Antarctic, mid ocean gyres and Eastern Boundary Upwelling Systems will be studied in detail and predictions of the impact of environmental change (increasing temperature, decreasing pH, decreasing oxygen, and changes in nutrient supply) on marine ecosystem dynamics will be examined. Biological oceanographic methods will be critically evaluated. It is hoped the module will include lectures from scientists from the Centre for the Environment, Fisheries and Aquaculture Science (CEFAS) and British Antarctic Survey (BAS).