Subterranean estuaries: An overlooked pathway for microplastic transport to our oceans

Microplastics (MPs) infiltrate marine environments through various pathways such as winds, rivers, and surface runoff. However, the role of subterranean estuaries as conduits for microplastics into our oceans remains poorly understood despite advances in microplastic monitoring. This study investigates microplastic contamination in the subterranean estuary of Malpe in southwestern India and quantifies the flux of microplastics entering the Arabian Sea through submarine groundwater discharge (SGD). The results reveal a mean (± standard deviation) microplastic concentration of 7.56 (±6.45) MPs/l within the subterranean estuary. The primary factor influencing the MP flux of microplastics in the subterranean groundwater discharge site is the seepage rate. The shape of the MPs recorded were mostly fibrous, which are sized between 1000-5000 µm. Polyethylene fibres specifically associated with local fishing activities was found to be the major contributor (96.82 Also see: https://micro2024.sciencesconf.org/559056/document