Characterization and heavy metals concentration of sediments from catfish ponds in Monai Cluster Fish Farm, Southern Basin of Kainji Lake, Niger State, Nigeria

Abstract

Fishpond sediments play a crucial role in aquaculture systems because they act as both sinks and sources for various nutrients and potential contaminants. In Nigeria's growing aquaculture sector, particularly in cluster fish farms, an understanding the characteristics of pond sediments characteristics particularly sediment quality is essential for sustainable management and environmental protection. This study focused on the Monai cluster fish farm, located in the Southern Basin of Kainji Lake, New Bussa, Niger State, Nigeria, where intensive catfish farming is practiced. The study aimed to characterize bottom sediments and determine the heavy metals concentration from catfish (Clarias gariepinus and Clarias hybrid) ponds in Monai Cluster Fish Farm. Sediment samples were collected from 90 grow-out catfish ponds across different seasons. Samples were analyzed for pH, nutrients (total nitrogen and phosphorus) and heavy metals following standard procedures. The study established seasonal patterns by comparing wet season (August and September) and dry season measurements. Results showed slightly acidic pH values (6.5-6.8), with phosphorus (orthophosphate) recording the highest nutrient concentration (2.2±6.1mg/l to 59.2±7.9mg/l). Wet season samples exhibited significantly higher concentrations of both total nitrogen and phosphorus, attributed to increased agricultural runoff and pond management practices. Heavy metal concentrations remained within EPA and WHO acceptable limits, indicating minimal contamination. Statistical analysis revealed no significant difference (p˃0.05) in physicochemical parameters across the cluster farm, likely due to the series connection of pond outlets and other water management and cultural practices. The findings highlight the need for implementing environmentally sustainable methods for sediment management and nutrient recycling within the fish farming value chain, particularly in cluster farm settings.