Blue mussels (Mytilus edulis spp.) as sentinel organisms in coastal pollution monitoring: A review

•An overview of blue mussel ecotoxicology and pollution monitoring was provided.•Factors that render blue mussels favorable as environmental sentinels were discussed.•Challenges related to influence from different confounding factors were discussed.•There is a need for standardization and harmonization of blue mussel monitoring techniques.•Internationally harmonized assessment criteria for prioritized contaminants specially adapted for blue mussel sentinels are needed.

The blue mussel (Mytilus spp.) is widely used as a bioindicator for monitoring of coastal water pollution (mussel watch programs). Herein we provide a review of this study field with emphasis on: the suitability of Mytilus spp. as environmental sentinels; uptake and bioaccumulation patterns of key pollutant classes; the use of Mytilus spp. in mussel watch programs; recent trends in Norwegian mussel monitoring; environmental quality standards and background concentrations of key contaminants; pollutant effect biomarkers; confounding factors; particulate contaminants (microplastics, engineered nanomaterials); climate change; harmonization of monitoring procedures; and the use of deployed mussels (transplant caging) in pollution monitoring. Lastly, the overall state of the art of blue mussel pollution monitoring is discussed and some important issues for future research and development are highlighted.