Research project Mixture toxicity assessment and validation of biological effect indicators using chemical activity

Assessing environmental quality within the EU Marine Strategy Framework Directive (MSFD) involves chemical and biological indicators of the contaminant pressure. Embryo aberrations in amphipods (ReproIND), reflecting exposure to complex chemical mixtures, is a supplementary indicator for biological effects of contaminants in Baltic sediments, yet this still needs to be validated. Chemical activity integrates these properties with contaminant quantities and provides a robust approach for addressing mixture toxicity. We will apply the chemical activity concept to better understand mixture effects and to develop a new approach for indicator validation. We aim to (i) provide a basis for comparing ReproIND data from different sites, (ii) test predictability of ReproIND and its specific components to the contaminant pressure; and (iii) facilitate indicator validation for management actions. The output will be used to develop a framework for validation of biological effect indicators across different basins and to promote ReproIND as the core indicator within MSFD.