Assessment of Water Quality Parameters in Fish Ponds of Smallholder Farmers in Anambra State

Smallholder fish farming in Anambra State, South East Nigeria, has expanded considerably in recent years, yet systematic documentation of water quality conditions in artisanal fish ponds remains limited. This study assesses selected physical, chemical, and biological water quality parameters in earthen ponds operated by smallholder farmers in Onitsha North and Ogbaru Local Government Areas. Water samples were collected from 30 ponds at fortnightly intervals over four months during the dry season and analysed for temperature, pH, dissolved oxygen, turbidity, total ammonia nitrogen, nitrite, nitrate, phosphate, and total coliform counts using standard methods. Results revealed that dissolved oxygen concentrations fell below the recommended threshold of 5 mg/L in 43% of sampled ponds, primarily in late afternoon. Total ammonia nitrogen exceeded safe limits for catfish culture in 37% of ponds, attributed to high stocking densities and infrequent water exchange. Pond pH ranged from 6.1 to 8.4, with most values within acceptable limits for Clarias gariepinus production. Temperature was within the optimal range for tropical fish culture throughout the sampling period. Strong correlations were observed between stocking density and ammonia nitrogen concentrations. The study identified inadequate feeding management and poor pond preparation as the primary drivers of water quality deterioration. The findings provide a baseline dataset for extension services targeting fish farmers in Anambra State and recommend regular on-farm water quality monitoring as a minimum standard for smallholder aquaculture operations.

Keywords: water quality, fish pond, smallholder aquaculture, ammonia nitrogen, Anambra State