Increasing atmospheric CO₂ concentration is causing increased absorption of CO₂ by the world's oceans, in turn driving a decline in seawater pH and changes in ocean carbonate chemistry that are collectively referred to as ocean acidification. Evidence is accumulating to suggest ocean acidification may directly or indirectly affect many marine organisms and ecosystems, some of which may also hold significant social and economic value to the Australian community. This report aims to provide a brief overview of the current state of scientific knowledge regarding the process of ocean acidification; current and future projected levels of ocean acidification; and, observed and projected impacts of current and future predicted levels of ocean a...