MICROPLASTIC POLLUTANTS IN Clarias gariepinus FROM IKPOBA RIVER, BENIN CITY, EDO STATE, NIGERIA.

ABSTRACT

One of the most recent and emerging contaminants today, is plastic. These plastics through improper waste disposal and runoff, find their way to water bodies. This plastic when they fragment or occur in very small sizes (<5mm) are termed microplastic. They can be classified on physical characteristics or chemical characteristics. They pose risk to both fish and consumers of the fish. The fish samples were analysed within 24hrs of collection. The fish were digested using 10% KOH, and purified using H2O2. The filtrates were examined under microscope to identify the microplastic particles, which were physically confirmed using the hot needle method and confirmed chemically using Fourier transfer infrared spectroscopy. Microplastics occur at all stations through the three months under study. The microplastics found based on morphological characteristics are pellet, foams, fibre, filaments, and fragments, while on polymer characteristics, there were two namely; polypropylene and polyethene. The type of microplastic prevalent in each station had a relationship to the prevalent economic activities at the watershed. For example, at station 3 (Ikpoba bridge), the prevalent economic activities at the water fronts are car and rug washes, the prevalent plastic is polypropylene. The level of microplastic found in each station had a relationship with the population and rainfall, as it increases with increasing population and increasing rainfall. The plastic load for all samples was 1.37 microplastics particles per fish which is in agreement with the findings of several authors. The frequency of occurrence of microplastic ingestion of 59.2% which is far lower than those obtained by various authors which give 96% and 100% respectively.