26 DECEMBER 2014 • WORLD AQUACULTURE • WWW.WAS.ORG located in Kubu, Bali raises specific pathogen-free L. vannamei in ponds, applying basic biofloc technology with no water exchange. Ample aeration and well-controlled dissolved oxygen concentration maintained good water quality in the culture environment. The farm has produced 45-55 t/cycle since 2009 in a stable and sustainable way from 12 small concrete ponds with a total surface area of 2 ha (Taw and Setio 2014). The technology also has been applied in super-intensive raceways production as high as 9.9 kg/m2 (Samocha et al. 2012) and 7.5 kg/m3 (Otoshi et al. 2006). The technology was applied for other species of shrimp, such as P. monodon in Australia by CSIRO in 2008 and freshwater prawn Macrobrachium in India. It has also been applied in blue shrimp L. stylirostris broodstock production (Cardona et al. 2014). That study compared two culture systems, clearwater and biofloc, and confirmed that biofloc is beneficial to the reproductive performance of blue shrimp broodstock and larval quality. Biofloc Technology and Biosecurity With emerging viral problems and rising costs for energy, biosecurity with biofloc technology appears to be an answer for sustainable production (Table 4). Large shrimp farms, which initiated biofloc technology in Sumatra, Indonesia from late 2002 to 2007, have not experienced any WSSV outbreaks (Taw 2010). As at other farms in the vicinity, Arca Biru shrimp farm, Blue Archipelago Berhad was faced with serious outbreaks from white spot syndrome virus (WSSV) before the redesign. During its first new cycle, viral incidents were common in the vicinity. On one occasion, dead WSSV positive shrimp were found within the main supply canal. Despite this, the production cycle was a success, without viral outbreaks (Taw et al. 2011) A large-scale “integrated shrimp aquaculture park” (iSHARP) project started by Blue Archipelago Berhad in Malaysia in 2009 had a goal to complete over 600 ponds and reservoirs for raising Pacific white shrimp on 1,000 ha of land at Setiu, in the state of Terengganu, northeast of Kuala Lumpur. The first stocking was initiated in October 2011. A total of 144 ponds were in operation by midNovember 2012. No incidents of white spot syndrome (WSSV) or early mortality syndrome (EMS) have been reported at the facility (Taw et al. 2013) (Fig. 6). The small family-owned shrimp farm located in Bali referred to previously has produced shrimp continuously since 2009 in a stable and sustainable way without WSSV and IMNV outbreaks (Taw and Setio 2014). TABLE 1. Basic management concepts in shrimp culture. TABLE 3. Comparative performance and technical features of intensive biofloc and greenwater systems for shrimp. TABLE 4. Biosecurity attributes of biofloc systems. TABLE 2. Desired concentrations of select water quality variables in biofloc systems applied to commercial shrimp farming. VARIABLE VALUE NOTE Salinity 20-35 ppt Temperature 25-30 C DO > 4.0 mg/L pH 7.3-8.4 Alkalinity > 70 mg/L as CaCO3 tends to reduce with duration of culture period TAN < 1.5 ppm higher than autotrophic system NH3-N < 0.1 ppm higher than autotrophic system Nitrate (NO3) < 5.0 ppm higher than autotrophic system PO4-P < 2.0 ppm
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