Develop tools and indicators for the assessment of biological effects of anthropogenic chemical stress in the Baltic Sea by investigating the causality between chemical pressure and biological effects at different levels of biological organisation. One outcome of the project will be recommendations for monitoring the effects of hazardous substances in the whole Baltic Sea Region. The project will also contribute to capacitybuilding and network-strengthening via workshops. Achievements: The BEAST project targeted the need (HELCOM BSAP, EU MSFD) of scientifically based tools for integrated monitoring and assessment of chemical pollution and biological effects in the Baltic Sea ecosystem. Field and experimental studies were done and the results were tested and validated for the assessment of Ecosystem Health. A multi-level toolbox including biomarkers as sensitive diagnostic tools was developed. A comprehensive Baltic-specific database on biological effects of contaminants was constructed. Capacity building, networking, exchange and inter-calibration of methodologies, and training were integral parts of the project. BEAST suggested a set of biological effects indicators to be included in a future Baltic Sea monitoring programme. Four of these indicators were suggested as core indicators for hazardous substances by HELCOM via the CORESET project. The HELCOM core indicators will be monitored by all Baltic Sea countries to assess Good Environmental Status (GES) of the Baltic Sea. Practical implementation of results from the project has also been made by both the European Commission and national authorities.