ABSTRACT
The Warri River, a crucial waterway in Nigeria's Niger Delta region, plays a pivotal role in maintaining the local ecosystem and supporting the livelihoods of nearby communities. Nevertheless, it faces ongoing pollution concerns primarily attributed to human activities which have resulted in the degradation of water quality and the subsequent deleterious effect in fish populations. In this study, Health Assessment Index (HAI) method was employed to assess the health status of indigenous fish (Coptodon guineensis) from Warri River. Fish (n=20) were collected from a period of three months (May to July, 2023) from Agbarho, Enerhen, and Udu designated locations along Warri River. Collected fish were examined for any external or internal abnormalities. Histological examination of organs such as the gills, kidney, liver, and spleen revealed abnormalities like atrophied glomerulus and Visible fatty change was observed in the kidney, the liver revealed congested central vein with mononuclear inflammatory cells, spleen showed mild apoptic changes and visible reactive changes, reduced cellularity of germinal vesicles and yolk grannules was observed in the Gonads and Visible fatty changes and also The secondary lamellae appeared fused and thickened in the gills from the various stations. Iron (Fe), zinc (Zn), copper (Cu), cadmium (Cd), chromium (Cr), and lead (Pb) concentrations were also examined in water and sediment samples. The heavy metals were in ranking order of accumulation in the fish muscle with Zn >Fe> Cu> Pb> Cr) >Cd. Correlation between the heavy metals and organs of fish showed that accumulated metals in organs had the highest histological abnormality, indicating a strong association between metal exposure and tissue damage. In general, this study revealed that fishes from Warri River are significantly affected by pollutants such as heavy metals, and this has resulted in the deleterious consequences observed in the Coptodon guineensis inhabiting Warri River. Thus, constant monitoring of this water body is essential as this species serves as a source of food and can pose serious health risks if they are constantly consumed.
