Eco-friendly thermoplastic-basalt composite buoy system: eliminating microplastic pollution in marine oyster farming

This research addresses the marine microplastic crisis in South Korea’s oyster farming industry, which relies heavily on Expanded Polystyrene (EPS) buoys that fragment and pollute coastal ecosystems. Annually, an estimated 8–12 million metric tons of plastic waste enter the world’s oceans, with EPS buoys contributing significantly to this problem. To provide a sustainable alternative, we developed a novel buoy system made from a thermoplastic-basalt composite. The thermoplastic matrix allows for full recyclability, which eliminates end-of-life disposal issues and contributes to a circular economy. Through finite element analysis (FEA), we confirmed the buoy’s structural integrity under extreme conditions. Our findings demonstrate that an 8-ply design provides excellent safety margins and impact resistance, preventing fragmentation and the release of microplastics. This system offers a significantly extended service life compared to conventional EPS buoys (1–2 years), with preliminary field data indicating excellent durability exceeding 5 years, representing an economically viable solution that supports sustainable aquaculture.