The use of Cerastoderma edule and Cerastoderma glaucum as bioindicators of pollution

Cockles ( Cerastoderma spp.) are benthic organisms with substantial economic, commercial and ecological value. They are used in environmental studies due to their filtration capabilities, sediment-dwelling nature, suitable size, and capability to accumulate contaminants in their tissues. Given their ecological relevance, this review aims to provide a comprehensive synthesis of studies addressing the use of cockles as bioindicators of aquatic pollution. Present findings reveal that Cerastoderma edule and C. glaucum have predominantly been employed in field-based assessments of pollution across coastal areas, estuaries, and lagoons, whereas laboratory-based investigations remain relatively scarce. Most reviewed studies were mainly conducted in Portugal, Tunisia, and France. The majority of the field studies focused on the bioaccumulation of metals and metalloids, with particular attention to Cd, Pb, Zn and Cu, while few studies addressed the effects of emerging contaminants, including microplastics and pharmaceuticals. Based on the present outcomes, in conjunction with bibliometric insights into research developments and trends, further investigation is recommended, particularly regarding the effects of climate change and emerging contaminants, which are becoming increasingly prevalent in aquatic systems. • Most Cerastoderma spp. pollution studies were conducted in Portugal, Tunisia, and France. • Research increased from 2000 to 2019, with a focus on metal contamination in estuaries. • Field studies dominated, with 71% of research assessing pollutants in natural habitats. • Emerging contaminants as microplastics and pharmaceuticals gained attention post-2016. • Portugal led in laboratory studies, exploring biomarker responses to multiple pollutants.