Microbiological Examination of Fish Pond Water and Its Influence on Tilapia Health in Fish Farms in Benue State

The microbiological quality of pond water in fish farms directly influences the health of cultured fish and the safety of aquaculture products consumed by households across Nigeria's North Central food belt. This study examines the microbiological quality of fish pond water and its relationship with health parameters in tilapia (Oreochromis niloticus) at fish farms in Benue State. Water samples from 12 tilapia ponds in Makurdi and Gboko were collected monthly over four months, alongside mucus swabs from fish displaying signs of ill health. Total coliform count, faecal coliform count, heterotrophic plate count, and selective isolation for Aeromonas, Pseudomonas, and Vibrio species were performed on water samples. Fish swabs were processed similarly. Total coliform counts exceeded recommended aquaculture limits in 67 percent of ponds, with higher loads in ponds receiving untreated effluent runoff. Aeromonas hydrophila was isolated from 75 percent of diseased fish swabs and correlated with ulcerative skin lesions and fin rot. Pseudomonas fluorescens was recovered from both diseased fish and pond water in three farms. A significant positive correlation was established between pond water coliform count and fish disease prevalence. The study recommends regular pond water quality monitoring, restricted organic waste input, and periodic pond disinfection as integrated fish health management practices in Benue State. Keywords: fish pond water, Aeromonas hydrophila, tilapia health, aquaculture, Benue State