Abstract
Marine and freshwater environments are under increasing pressure from anthropogenic stressors. The resulting impacts on exposed ecosystems are complex and challenging to characterise. The effects may be subtle and exhibited over long time periods. Effective and robust approaches are required to characterise the physiological and genetic processes that are impacted by pollutants to assess how populations and ecosystems may be adversely affected and at risk. The objective of the review is to provide an overview of "omics" methodologies used to assess the risk of stressors on exposed biota. This review covers the development of key omics approaches and how they have been used to contribute towards improved knowledge about the effects of environmental stressors, from molecular to whole-organism and community levels of biological organisation. We provide insights into how ecotoxicogenomics approaches can be used for various aspects of environmental risk assessment by characterising toxicological mechanisms of action. This information can be used to confirm cause-and-effect relationships required to better manage risks and protect the integrity and functionality of ecosystems.