Baseline characterisation of microplastics in surface water, sediment, and seafood from the Escravos Estuary, Nigeria

Abstract

Microplastics (MPs) are pervasive global contaminants with significant ecological and public health implications. This study establishes baseline data on MPs in water, sediment, fish, crab, and periwinkle from Okerenkoko and Kurutie along the Escravos Estuary in the Niger Delta. Samples were analyzed using microscopic observation and FTIR-ATR spectroscopy. MPs ranged from 4.2 µm to 800 µm, with 134 particles identified: 50 particles/L in water and 29 particles/kg/dw in crabs. Fibres (40 particles) and fragments (35 particles) were predominant, with Okerenkoko contributing 74 particles and Kurutie 60 particles. Fibres and filaments were prevalent in both locations, while pellets were absent in Kurutie. Notably, blue was the dominant colour, with 60 % of filaments and 70 % of fibres in Okerenkoko, and 40 % of fibres and 36.36 % of filaments in Kurutie. Water samples showed an average of 0.33 ± 0.21 particles/L for films and 3.67 ± 0.49 particles/L for fibres. Statistical analysis revealed no significant differences in nurdles, pellets, fibres, and filaments across samples (P > 0.05). Principal Component Analysis indicated industrial sources for certain MPs, while linear regression revealed a weak negative relationship between MPs concentrations in different matrices (adjusted R² = 0.053). FTIR analysis identified polystyrene in water, nylon in sediment and fish, PVC in Kurutie sediment, and PET in crabs, suggesting varied pollution sources. These findings highlight the urgent need for ongoing research, improved waste management, and heightened public awareness to mitigate MPs pollution and safeguard ecosystems and human health in the region.