From personality to environmental risk: an (eco)toxicological perspective of behaviour

Behavioural alterations in fish are increasingly used as sensitive endpoints in (eco)toxicology, providing insights into the effects of a wide range of newly developed chemicals/materials, environmental contaminants and abiotic stressors on aquatic wildlife. Within this context, fish personality, defined as consistent interindividual differences in behaviour across time and contexts, has been receiving increasing attention as a potential modulator of exposure, physiological sensitivity, and behavioural responses to environmental stressors, with potential population-level consequences. This review synthesises current evidence linking fish personality to contaminant exposure and sensitivity. The experimental frameworks and behavioural assays used in ecotoxicological studies were critically evaluated, revealing limitations in standardisation, repeatability, comparability, and ecological relevance. Overall, the review highlights how incorporating personality-based approaches can enhance the ecological realism of environmental risk assessment, while identifying key methodological gaps and challenges that must be addressed to improve the robustness and interpretability of behavioural endpoints in (eco)toxicology.