Occurrence of Microplastics in the Tissues of Nile Tilapia (Orechromis niloticus) from Zobe Dam, Katsina State, Nigeria

Abstract

A study of the detection of microplastics on Oreochromis niloticus in Zobe Reservoir, Katsina State, Nigeria was carried out. Three fish sampling sites were used; the upstream (Tsawatsawa), midstream (Makera), and downstream (Garhi) were selected based on variation of anthropogenic activities. A total number of one hundred and forty-four (144) fish samples with a total weight (MTW) and total length (MTL) varied between 134.1 ±1.50 to 154.2± 3.41g and 17.5 ± 0.10– 22.1± 0.54 cm respectively, were collected and analysed for the presence of microplastics using standard protocols. Fourier Transform Infrared Spectrophotometer (FTIR) was used for the chemical characterization of microplastic composition examined in the fish species. The examination of microplastic occurrence in different sampled fish gills, liver, and kidney revealed the presence of Polystyrene, Polypropylene, Polyethylene terephthalate, Nylon, Polyester, and Polyvinyl chloride. Fish from all sampling sites revealed varying histopathological alterations ranging from lifting of epithelium thickening, distortion of the primary lamellae, and degeneration of secondary lamellae, blood congestion, and massive lamellae degeneration in the gill tissues. Liver tissues had hepatocyte hypertrophy, sinusoidal dilatation and cytoplasmic vacuolation, presence of lipid granules, cellular infiltration, cytoplasmic vacuolation, and haemorrhage. The kidney tissues were presented with Bowman’s capsules hyperplasia, tubular elongation, renal tubular epithelium shrinkage, hyperplasia, and cytoplasmic vacuolization of renal cells. The severity of the damage varies from site to site indicating that the water body is experiencing pollution at varying locations. Our findings provide important insights into the prevalence and distribution of microplastics in this particular environment.