Abundance and Seasonal Variation Of Microplastics Detected in Edible Fish Sold in Lagos State, Nigeria

Abstract

The global incidence of microplastics pollution is raising safety concerns on the consumption of seafood by humans. This study investigated the seasonal variation of microplastics detected in fish sold for human consumption in Lagos State, Nigeria. A total of 150 fish samples consisting of 3 commercially important fish species, namely: Catfish (Clarias gariepinus) n=25, Red Snapper (Lutjanus campechanus) n=25 and Tilapia (Oreochromis niloticus) n=25 sold for human consumption were purchased from fishermen from 3 sites in Lagos State during the dry season from 22nd January to 7th February 2020 and during the rainy season from 13th to 25th July, 2020. The stomach contents of the fish were analyzed for the presence and characterization of microplastics. The identified microplastics were categorized according to their abundance, sizes, shapes, types, and colours using Dissecting Microscopes and FTIR. Microplastics particles were detected in all samples studied from all locations in both seasons, with the highest level of microplastics abundance detected during the rainy seasons. Highest microplastics abundance was detected in catfish (4.68 microplastics particles per individuals) during the rainy season in Badagry and 5-Cowries Creeks and the least detected in Red Snapper (0.72 microplastics particles per individuals) in Epe and Badagry during the dry season. Majority of the detected microplastics were fiber-shaped, followed by fragments. The least microplastics shape was foam. The most common color of microplastics during both the wet and dry seasons was grey/white (25.0%) while pink (2%) was the least dominant colour. The size of the ingested microplastics ranged from 2.03 mm to 4.86mm during the dry season while the particle sizes found in the species during the rainy season ranged from 1.49mm to 4.95mm. The results of FTIR-ATR analysis indicated that polyethylene (PE) was the most abundant in both seasons. The findings from this study raises concerns on the implication of microplastics on food safety.