MICROPLASTIC POLLUTANTS IN THE NILE TILAPIA (Oreochromis niloticus)

ABSTRACT

Microplastics are known to accumulate in various environmental compartments and can devastatingly contaminate fish, water and sediments which in turn present a risk to humans. The dearth of ecotoxicological data with regard to the microplastic concentration in Oreochromis niloticus from River Okhuo in Benin City, Edo State, Nigeria, called for this research. The types of microplastics results were; polyethylene and polypropylene from June, 2023 to August, 2023. The fish samples from river okhuo were carried in an ice box and immediately conveyed to the laboratory, within 24 hours. The fish samples were removed from the freezer and rinsed thoroughly with running water to remove debris. Total fish length was measured from mouth to tail, with a precision of 1 mm, (using a graduated ruler on a wooden board) and were weighed with an electronic semi-analytical balance, they were digested in 10% KOH solution. The beaker was covered and was safely stored away for a period of 14-22 days. Alternatively, the fish sample was left to digest in closed vials overnight at 60C in an oven before analysis, which was achieved by Fourier transform infrared (FT-IR) imaging. 27 specimens of Nile tilapia (Oreochromis niloticus) were collected in June, July 2020, and August 2023. The collected fish were dissected in the laboratory, where the number and type of microplastics were analyzed in the gut, after their separation by digestion and filtration. The presence of microplastics in tilapia from River Okhuo is an indicator of contamination in the River by pollutants that could affect the trophic network and represents a risk for the fish consumers, requiring the attention of environmental and health authorities.