The dispersion of commercial plastics in the marine environments is a major threat to biodiversity and ecosystem services of the last decade. The lower density of the plastics with respect to marine water density determines their floating, transferring, and accumulation in sandy beaches. Sandy beaches represent a natural sink ecosystem for marine plastics, where the latter are fragmented and photo-degraded in relation to the kind of polymer. Here, we propose an accurate and cost-effective method, the differential scanning calorimetry (DSC), to identify different polymers from plastic samples collected on the Aquatina di Frigole beach (Apulia Region, southeast of Italy), included in the NATURA 2000 Site coded as IT9150003. Our results reveal the exclusive presence of thermoplastic polymers in the beach plastic samples, mostly belonging to the polyolefin family. They appear to be remnants of larger plastic fragments, which could impact biodiversity and ecosystem services such as beach recreation activities and tourism.