Plastic Pollution in Sediments and Marine Fish Species from Two Artisanal Fishing Hotspots Along the Coast of Ghana

Abstract

Plastic pollution is a global environmental challenge that threatens marine biodiversity and ecosystem health. The focus of this thesis was to evaluate the level of plastic pollution along the coast of Ghana and also, to examine microplastic contamination in some marine fish species. The study was conducted at two of the largest artisanal fishing harbours– Elmina and Tema – in Ghana, West Africa. Macroplastic (> 2.5 cm or 25 mm) and mesoplastic (5 mm to 25mm) litter on and within the beach sediments of the harbour was analysed based on international guidelines for monitoring marine litter. Followed by microplastic (≤ 5 mm) contamination analyses of two commercial fish species, Angola dentex (Dentex angolensis) and Barracuda (Sphyraena sphyraena) landed in the harbours, using the Fourier transform infrared (FTIR) spectroscopy analysis. The marine litter analyses (macroplastic) indicated a diversity of plastic materials mostly dominated by single-use plastics (water sachet and takeaway bags). The results from the mesoplastics analyses specify the dominance of styrofoam and hard plastic fragments as the dominant materials. The FTIR results showed a higher occurrence of microplastics in Dentex angolensis at Elmina, with microfibers accounting for 60-100% of the ingested microplastics. Five different polymer groups were identified, with polyethylene, polystyrene, and polyurethane being the most commonly consumed polymers. Although plastic ingestion was low, it could be traced to the plastics evaluated along the coast. All stakeholders must pay attention to addressing pollution, especially plastics, to prevent further contamination of marine life.