Monitoring Plastic Pollution in Coastal Beaches of Lagos State, South West Nigeria

Plastic pollution on Nigerian coastal beaches has escalated alongside rapid urbanisation and inadequate solid waste management infrastructure. This study monitored the distribution, composition, and density of plastic debris on four beaches in Lagos State spanning urban, peri-urban, and tourist zones. Standardised beach transect surveys were conducted following protocols adapted from the OSPAR marine litter survey guidelines. All visible macroplastics were collected, categorised by type, and weighed. Microplastics were extracted from surface sand samples using sediment sieving and density separation. Results showed that plastic packaging, polystyrene food containers, and single-use bags constituted over 70 percent of total macro-litter by item count across all beaches. Microplastic concentrations were highest at the urban beach, reaching 1,480 particles per kilogram of dry sediment, with fibres and fragments as the dominant morphological types. Seasonal comparisons indicated substantially higher litter densities following wet season high-tide events. The study highlights the role of riverine transport in delivering inland waste to coastal zones. Recommendations include municipal solid waste management reforms, extended producer responsibility policies targeting single-use plastics, and community-led beach clean-up initiatives reinforced by environmental education in coastal schools. Keywords: plastic pollution, beach litter, microplastics, Lagos, coastal environment.