Aquaculture and Shrimp Culture :: New Aquaculture Technology

Aquaculture in general and shrimp culture in incident have recently been developing strategies of super-intensive cultureswithout water exchange. This approach addresses environmental questions raised by both society and the scientific community regarding sustainable development concepts which pauperism a convergence of ecological prudence, economic efficiency and social equity in all human activities (Bailey, 1988 Brown, 1989 Pruder, 1992 Macintosh and Phillips, 1992 Kinkelin and Michel, 1992 Pe rez, 1993 Currie, 1994 Primavera, 1994 Rosenthal, 1994 Larsson et al., 1995 Kestemont, 1995).Pioneer work such as Reid and Arnold (1992) and Williams et al. (1996) demonstrated that it is possible to produce shrimp at high density in raceway systems that use water recirculation. The recent progress made in the area of super-dense cultures, also known as suspended-growth systems (Hargreaves, 2006) and active suspension ponds (Avnimelech, 2006), reinforces the idea that it is possible to pro duce aquatic organisms in an intensive and especially bio-safe way. The absence of effluents, the step-down of utilized space, and the dramatic reduction of the introduction of infectious diseases, are the main criteria for justifying its development (McNeil, 2000 McAbee et al., 2003 Burford et al., 2003, 2004 Pruder, 2004 Sowers et al., 2005 Wasielesky et al., 2006 Azim and Little, 2008 De Schryver et al., 2008 Schveitzer et al., 2008).Although this relatively new aquaculture technology is still developing (De Schryver et al., 2008), important inquiry effortshave been made with the objective of comprehending the physical, chemical and biological phenomena present in the water that dictate the dynamic of the cultures (Hopkins et al., 1993 Moss and Pruder, 1995 Sandifer and Hopkins, 1996 Davis and Arnold, 1998 Avnimelech, 1999 Browdy et al., 2001). Some studies suggest that shrimp culture in a closed system (without water exchange) can maintain water quality considered acceptable f or these organisms (Thakur and Lin, 2003). Others suggest that the water quality, in spite of being brusk due to the large quantity of nutrients that are accumulated over time, is sufficient to guarantee the growth and survival of the animals (Burford et al., 2003). Hargreaves (2006) criticizes the majority of studies regarding these so-called suspended-growth systems, because they suggest that the role of the bacteria in reference to the maintenance and the improvement of the water quality is more important than the phytoplankton metabolism.The importance that primary productivity has in the cultures (extensive, semi-intensive, polycultures, etc.) of different organisms is well-documented (Noriega-Curtis, 1979 Laws and Malecha, 1981 Chang and Ouyang, 1988 Yusoff and McNabb,