Assessing the effects of farming on water quality of fish farms in Ghana: the case study of Sunyani Municipality

Abstract

This research examines the effects of farming activities on water quality of fish farms located in the Sunyani Municipality of Ghana. Six fish farms were selected for the study, including three fish farms close to farming activities (WFA) and another three far from farming activities (WOFA). Water samples were obtained monthly between May and September 2023, and analyzed for physicochemical parameters. The results showed that concentrations of nitrate, nitrite, total suspended solids (TSS), and total dissolved solids (TDS) were significantly higher in the farms without farming activities (with averages of 43.28 ± 2.83 mg/L for nitrate, 0.16 ± 0.05 mg/L for nitrite, 187.60 ± 24.30 mg/L for TSS, and 148.70 ± 12.90 mg/L for TDS) compared to farms linked to farming activities (18.40 ± 2.83 mg/L for nitrate, 0.05 ± 0.01 mg/L for nitrite, 103.60 ± 15.90 mg/L for TSS, and 113.60 ± 11.30 mg/L for TDS). Principal Component Analysis (PCA) revealed that pH and sulfate had positive coefficients (0.55 and 0.63, respectively) in farms with farming activities, whereas nitrate had a positive coefficient (0.52) in farms without farming activities. The high levels of water quality parameters in the farms without farming activities were attributed to internal pond mechanisms, while farming activities were observed to significantly influence sulfate concentrations in the fish farms. In conclusion, the study demonstrates that agricultural runoff and nutrient leaching directly increased sulphate concentrations in fish farms, disrupting water chemistry and posing risks to aquatic ecosystems and fish health. Based on the findings, structured water testing schedule can help detect changes in key parameters such as pH, nitrate and ammonia levels should be formulated and implemented. Also, a 100-meter buffer zone between fish farms and farming areas to prevent contamination should be established.