This report collates information on ecosystem-based indicators and indices currently being measure by regional entities and seeks to identify common elements. From this analysis the report postulates whether a limited generic set of indicators can be derived. A series of case studies are used to exemplify the diversity of ways indicators have been applied. For State of the Environment reporting, ecosystem-based indicator systems have developed in an ad hoc way, influenced by regional pressures and priorities. Indicator systems linked to targets and objectives have been more coordinated (e.g. Transboundary Waters Assessment Programme) and the European Environment Agency (EEA) approach to indicators is an example of pan-regional coordination associated with regulatory requirements.