Pond water dynamics and cultivation performance of super-intensive whiteleg shrimp (Litopenaeus vannamei) farming in membrane-based recirculating aquaculture system

Super-intensive aquaculture offers a viable strategy to maximize shrimp production while minimizing environmental impact. This study developed and evaluated a membrane-integrated recirculating aquaculture system (M-RAS) for the cultivation of whiteleg shrimp (Litopenaeus vannamei). The system incorporated ultrafiltration (UF) membranes to pretreat seawater and remove suspended solids and pathogens prior to pond entry. Four cultivation ponds (20 m2 each) were stocked at a density of 400 shrimp/m2 and operated over a 100-day cycle. Nutrient residues from uneaten feed and shrimp waste were treated using a biofiltration unit comprising solid removal, denitrification, nitrification, and sludge separation. Water quality was maintained through routine siphoning, partial water exchange, periodic harvesting, and addition of Ca(OH)2, sugar, and nitrifying bacteria. Key water quality parameters, including DO, salinity, turbidity, pH, and nitrogen compounds, remained within acceptable ranges, although temperature (25.7–28.4 °C) was slightly below optimal. Cultivation performance metrics were favorable, with a survival rate of 86.85% ± 2.10%, daily weight gain of 0.25 ± 0.03 g/day, final average body weight of 25.09 ± 0.71 g, productivity of 4.71 ± 0.31 kg/m2, and a feed conversion ratio of 1.57 ± 0.07. These results demonstrate the potential of M-RAS as an effective and sustainable system for intensive shrimp farming.