Impact of fish pond manuring on microbial water quality

Fish pond manuring is often used in fish farming for intensification of fish production by balancing the ratio between carbon and other nutrients. However, the using of manure, classified as hazardous organic matter originating from animal faeces, poses a risk to the water environment.The aim of this study was to evaluate the effect of semi-liquid pig manure application on faecal pollution and related potential health risk of fish pond utilization.The evaluation of faecal pollution was made during 6 years; the microbiological monitoring was completed with the water chemistry data. Our results showed that a better situation was in ponds, processes of which can be regulated by changes in nutrient contents, i.e., by controlled manure application. The absolute counts of microbial indicators were not significantly different in the control non-manured and manured fish ponds, but sporadically detected high faecal indicators counts in summer can represent a potential health risk. According to our results, the water quality of fish ponds is influenced due to manuring but the immediate impact of manuring in fish ponds and recipients in our study proved neither in deterioration of microbiological quality and health risk enhancement nor in the water quality assessed by chemical analyses.