Evaluation of Water Quality in Fish Farms & its Effect on Performance.

      Аннотация: A field study was carried out in four fish farms in different localities in Egypt to investigate the water quality of fish farms with different water sources (fresh , brackish , agriculture and ground water) and its effect on fish performance ( growth & survival rate ) beside parasite infestation of cultured fish . Results revealed that although the average values of physio-chemical and bacteriological parameters were within the acceptable limits at water inlets in examined farms; a great variation were recorded among both Farms and ponds within the same farms as water in ponds of farm (IV) showed a significant increase in the measurable parameters P <0.05 with a significant decrease in dissolved oxygen followed by pond 2 in farms (III) and (I) respectively (3.6±0.7, 4.9± 0.61 and 6.5±0.31 mg/l). Meanwhile farm (II) showed a significant decrease P < 0.01compared with other examined farms. Faecal coliforms were isolated from water ponds and fish in farms I, III and IV (1.0±0.12, 5.02±0.5, 14.0±3.6 and 23.0± 4.3/ 100ml) & (0.4±1.5, 1.6±1.5, 4.0 ±1.0, 10.8±1.2, 10.6±3.0 and 12.0±3.2 respectively).

Ключевые слова: Fish performance, Water Quality, aquaculture.