Журнал исследований и разработок в области аквакультуры

Абстрактный

The Applicability of Activated Carbon, Natural Zeolites, and Probiotics (EM^®) and Its Effects on Ammonia Removal Efficiency and Fry Performance of European Seabass Dicentrarchus labrax.

Hadir A Aly, Mohamed M Abdel Rahim, Ayman M Lotfy, Basem S Abdelaty and Ghada M Sallam

Ammonia is toxic to fish if allowed to accumulate and not-properly managed in fish production systems. Six treatments were studied to evaluate the effectiveness of applying three commercial Ammonia Removal Products (Activated Carbon, Natural Zeolite and Effective Micro-organisms (EM®)). These treatments are: (1) C, Control, (2) AC5, activated carbon at 5ppt, (3) AC10, activated carbon at 10 ppt, (4) Z5, Zeolite at 5 ppt, (5) Z10, zeolite at 10 ppt, and (6) EM400, EM at 400 ppm. European Seabass fry (240.74 mg/fish IW) were stocked into glass aquaria (50 litres each) at density of 20 fry/aquarium. Water exchange rate was 20% daily and the experiment continued for 35 days. Fish were fed on experimental diet contained 51.37% crude protein, three meals daily, and six days weekly. Data of water quality, survival and growth performance were recorded weekly. The results revealed that, ammonia removal efficiency of the tested products was significantly (P ≤ 0.05) better than control, with no significant differences (P>0.05) between the evaluated products. The best ammonia removal rate (76.60%) was obtained at Z10 treatment. Fish survival (%) ranged between 37.78% to 90% with highly significant (P ≤ 0.05) differences between treatments. The best survival (%) was obtained at EM400 (90%), while the lowest (37.78%) was obtained at AC5 and AC10 treatments. Growth performance was significantly (P ≤ 0.05) higher at (EM400, Z10, and Z5), compared with treatments (AC10, AC5, and C). It could be clearly concluded that, using Probiotics (EM®) and Zeolite for ammonia removal might be a good potential alternative choice, while activated carbon cannot be recommended for marine fish rearing tanks in terms of low survival and growth performance and also the higher expected production cost.