WWW.WAS.ORG • WORLD AQUACULTURE • MARCH 2016 15 (CONTINUED ON PAGE 16) substantially decreases hatchery production costs compared to stocking larger juveniles (20-30 g). Commercially available dry feeds with high protein (50-55 percent) and lipid (11-14 percent) content are commonly used during the nursery phase, with a transition to fresh-frozen sardines (trash fish) and/or moist diets composed of fresh-frozen sardines, commercially available high-protein feed and vitamin and mineral premix during intermediary phase and first months of the growout period. During the final 3-4 months of grow-out, cobia are fed fresh or frozen sardines to yield a high-quality fillet rich in omega-3 fatty acids. It is important to highlight that this region is one of the major landing ports of sardines in Brazil, where fresh-frozen sardines with no market value are typically disposed in public landfills. With implementation of proper management practices to avoid contamination, they can be used as a highOperators Association of Ilha Grande Bay) which produces fingerlings for local farms, research facilities and social projects. The hatchery was established in 2013-2014 with financial and technical support from two foundations, Fundação Instituto de Pesca do Estado do Rio de Janeiro (FIPERJ) and Fundação Carlos Chagas de Amparo a Pesquisa do Estado do Rio de Janeiro (FAPERJ). In the State of São Paulo, there are two private marine fish hatcheries, Maricultura Itapema and Redemar Alevinos, focusing on cobia and grouper production. Both facilities are located 6-8 hours from Angra dos Reis and commonly supply cobia fingerlings for local farmers and research centers. Grow-out. The grow-out facility is located apart from the marine finfish hatchery. Cobia are reared in a three-phase system over a 12-mo period: nursery (1.5-45 g), intermediate phase (45-500 g), and grow-out (0.5-4.5 kg). The grow-out protocol is illustrated in Figure 1 and information regarding stocking densities, cages, mesh size, and feed type is detailed in Table 1. Additional details on cobia grow-out protocols are described by Sampaio et al. (2011). Currently the grow-out facility consists of seven nearshore cages constructed of high-density polyethylene (HDPE): four are rectangular (3 × 6 m) and four are circular (three of 6-m diameter and one of 16-m diameter. A range of different feeds are used throughout the different grow-out phases (Table 1). One of the many benefits of the Angra dos Reis region is the potential to stock small juveniles (1.5-2 g) during the summer, a practice that TABLE 1. Cobia grow-out protocol. Culture phase Cage size Mesh size Useful cage Initial stocking Final stocking Feed type (m) (mm) volume (m3) density (kg/m3) density (kg/m3) 1 – nursery 3 x 6 x 2 3 30 <2 <5 Dry 2 – intermediate 6-m diameter x 3 12 90 ≈3 ≈8 Moist or trash-fish* 3 – grow-out 6-m diameter x 3 20 90 ≈5 ≈10 Moist or trash-fish* * Trash fish consists of fresh-frozen sardines (Clupeidae). Mussel (Perna perna) culture on surface longlines near cobia cages. Scallops (Nodipecten nodosus) cultured in lantern nets near cobia cages.
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