Coastal zone ecosystems and the goods and services they provide are under increasing pressure from anthropogenic impacts. Climate change and demographic effects are particularly relevant,and it is critical to establish proper control systems (policies) to protect and conserve the wideranging benefits that these systems provide. The concept of ‘holistic assessment’, the Ecosystem Approach,is now being widely promoted, but the relationship between the science supporting this policy and the development of the policy itself is not always well-coordinated. This Theme Section discusses applications of science to coastal zone management and provides a critique of some approaches.