The pan-Baltic BEAST project is targeted at developing integrated measures of chemical pollution and tools needed to detect and understand human-induced pressure on the Baltic Sea ecosystem. We will test and validate integrated monitoring and assessment approaches for their applicability in the Baltic Sea, taking carefully into account the specific abiotic and biotic characteristics of the sea area. Using sub-regional assessments we will provide scientifically based recommendations for the implementation of an integrated chemical-biological effects monitoring strategy for the assessment of ecosystem health. This supports ecosystem-based management to safeguard the sustainable use of ecosystem’s goods and services. To establish links between responses related to chemical pollution within the individuals and effects observed at higher biological levels we will generate an integrated “multi-level toolbox” including biomarkers as sensitive diagnostic tools. Capacity building, networking, exchange and intercalibration of methodologies, and training are another integral part of the project. Sixteen partners from all Baltic Sea countries are involved in BEAST; the work consists of field and experimental research using both established and novel methods on 5 Baltic Sea sub-regions so far with limited information on biological effects of hazardous substances. The outcome will be communicated to national and regional stakeholders and co-operation with HELCOM MONAS will be established.