Microplastics in tissues of the mussel Mytilus edulis platensis from the San Jorge Gulf, Atlantic Patagonian Sea

The San Jorge Gulf-Argentina (SJG) is the most populated area in Patagonia but information on its coastal environmental quality is scarce. Cities have grown in a disordered way along the coastline, and raised serious environmental conflicts, with occurrence of controlled and illegal coastal dumpsites along with effluents that release wastewater and rainwater into nearshore ecosystems. Microplastics (MPs) are recognized as an emergent threat since they can enter trophic webs and show complex ecotoxicological effects. Thus, we aim to assess MPs contamination in mussels (Mytilus edulis platensis) from different sites along the central coast of SJG as a biomonitoring approach. Mussels were collected at SM (impacted, within the urban area of Comodoro Rivadavia city), MAQ and QR (reference sites, distant 18 and 15 km S and N, respectively from urbanized areas). The soft tissues of 15 mussels per site were digested in pools of five individuals (n=3) using a 30% H2O2 solution (60 °C) and filtered through polycarbonate filters (10 µm). Procedural blanks were processed. Filters were examined thoroughly and all suspected MPs were tested with the hot-needle method under a stereoscopic microscope. The results indicated the presence of plastic and non-plastic microfibers of anthropogenic origin in all sites. Microplastic concentration was higher in the city (SM: 0.64±0.12 MPs/g w.w.) compared to more distant sites (0.49±0.19 and 0.31±0.05 MPs/g w.w. for MAQ and QR, respectively) (Dunn´s test QR vs SM, p Also see: https://micro2022.sciencesconf.org/426964/documentIn MICRO 2022, Online Atlas Edition: Plastic Pollution from MACRO to nan