Production Systems

Fish farming of sparids has started with the success in artificially hatched red sea bream (Pagrus major) larvae in Japan and domestication of sea bream (Sparus aurat) in the Mediterranean. Over the years the culture of these two species has developed into large-scale industries. This chapter focuses on production systems, covering with the hatchery stage, describing different rearing techniques and technologies, and finalizing with growout metabolic aspects and related environmental issues. Hatcheries of sparids include larval rearing, planktonic food chain production (both phytoplankton and zooplankton), and nursery sections. The process of larval rearing represents probably the major bottleneck of the rearing, as in all aquaculture activities. Hatcheries applying intensive or semi-intensive techniques are producing juveniles at size of 2-5 g that are transferred to an ongrowing cage or land-based systems, or may include a preongrowing period (up to a size of 10-30 g) in case of open sea cages. Floating cages in protected or semiprotected sites are the dominant technology used for the production of sea bream in the Mediterranean and are widely used for red sea bream in Japan aswell. Limited locations and increasing competition and conflicts with other users of coastal areas have promoted the development of offshore open sea cages. Land-based systems are used for sparids in Japan and in the Mediterranean for many years and developed from extensive to a modern and intensive production system, yet with limited use. The chapter also includes a quantitative description of four basic metabolic rates required for the design of a production system, using the sea bream as a model (growth; feeding; respiration of O2 and CO2; excretion of metabolites) and describes the required environment for culture in terms of water quality and photoperiod manipulations. At the last section, the impact of sparids production on environmental issues is discussed, including aspects of source impact, escapes, nutrient enrichment, and long-term sustainability issues. Finally, some future directions of research and development of sparids production systems is discussed, including further development of the mesocosm approach, advancing offshore technologies, and improving performances of land-based recirculating and integrated systems.