Bioaccumulation of environmental contaminants in crayfish: monitoring aquatic pollution and food safety risks

Freshwater ecosystems are increasingly threatened by complex mixtures of chemical pollutants originating from industrial, agricultural, and urban activities. This review synthesizes current knowledge on freshwater crayfish as bioindicators of aquatic pollution and the related food-safety hazards. Crayfish absorb contaminants from water, sediment, and diet, exhibiting tissue-specific bioaccumulation patterns for metals, organic pollutants, microplastics, and emerging contaminants. The hepatopancreas, gills, muscle, and exoskeleton provide complementary information on exposure pathways and contaminant bioavailability, enabling pollution sources, pathways, and site-level toxicity to be identified via crayfish analysis. The key advantages of crayfish as bioindicators reflect their benthic life, limited mobility, omnivorous feeding behavior, and relevance to freshwater food webs. Importantly, the widespread consumption of crayfish links environmental contamination to public health concerns, particularly in polluted or mining-impacted regions. This review underscores the value of integrating analyses in crayfish-based monitoring frameworks and discusses future perspectives for improving risk assessment and the sustainable management of freshwater resources.