Journal of Aquaculture Research & Development

Abstract

Use of Zero Water Discharge Technology through the Application of Nitrifying Bacteria and Textile Vertical Substrate in Grow-Out Phase of Macrobrachium rosenbergii De Man

Gede Suantika, Dea Indriani Astuti, Rifki R Arief, Malendra Rusni and Osman R Turendro

This study was conducted to develop a zero water discharge technology for Macrobrachium rosenbergii growth in order to solve the unpredictability of prawn production during grow-out phase.The system consists of three major compartments: (1) Prawn culture tank, (2) Trickling biofilter for nitrification process, and (3) Textile vertical substrate for prawn territory expansion. The trial was conducted in three diferent stages: (1) nitrifying bacteria of 105 Colony Forming Units.mL-1(CFU.mL-1) was inoculated into the culture 24 hours prior to juvenile stocking and every 10 days during culture period, (2) the culture was grouped into five treatments: 30 individuals.m2 (control), 40 individuals.m2, 50 individuals.m2, 60 individuals.m2, and 70 individuals.m2, and (3) measurements of biological, physicochemical, and microbiological culture parameters. Optimum culture performance was obtained in the culture with initial
stocking density of 30 individuals.m-2 (control) with final metabolic body weight, length, specific growth rate (SGR), survival rate (SR), feed conversion rate (FCR) of (11.37 ± 4.92) g, (10.69 ± 1.45) cm, 2.569%.day-1, 78.3%, and 0.99, respectively. However, from an economic perspective, stocking with 70 individuals.m-2 (treatment IV) produced the highest total final biomass (975 g) and highest profit (Rp. 19.285 per kg) compared to the other treatments. Results indicate that use of the developed zero-water discharge rearing system with the application of nitrifying bacteria and textile vertical substrate can maintain good water quality to support a higher stocking density, better growth and larval survival rate and profit of prawn M. rosenbergii de Man grow-out culture.