Efficiency of Using Recirculating Water System in Pacific White Shrimp (Penaeus vannamei) Rearing

Abstract

           The objective was to investigate efficiency of the recirculation water system with natural filtered materials used for vannamei shrimp rearing before stocking in cultured pond. There were two treatments including rearing in opened system and rearing in recirculation water system, activated carbon and oyster shell.  Shrimp (PL 20) were reared in 3,600 liter plastic tank with the density of 3,000 pieces/cubic meter. The experiment last for 30 days. Weigh, measure and weigh all shrimp weight. Then randomly measured shrimp larvae by 10 percent before and ending the experiment. The finding showed that water quality, in terms of ammonia and nitrite, were significantly different at 0.05 level between two treatments. The amount of ammonia and nitrite in recirculation rearing system (0.23±0.10, 0.49±0.20 mg/l) were less than the amount measured in the opened system (0.45±0.20, 4.19±3.30 mg/l). The same result found in growth rate and survival rate analysis.  Average weight gain, average length increased and survival rate of shrimp reared in circulation system (1.30±0.00 g., 4.30±0.00 cm. and 71.50±1.00 % respectively) showed statistically significant better values at 0.05 level compared  to the other system (1.26±0.00 g., 4.00±0.00 cm. and 65.98±0.99 % respectively).  The study results indicated that better water quality in particular ammonia and nitrite showed in recirculation rearing system with natural filtered materials. Moreover, the better results were also found in shrimp growth and survival rate. Therefore, this rearing system could be one of the efficient methods used for shrimp farmers to save their working time and reduce environmental impact.)