CONCEPTUAL DESIGN OF A SUSTAINABLE POND-BASED SHRIMP CULTURE SYSTEM

Estuaries are used as both water source and effluent disposal areas fo r shrimp farms. Feeding rates rise as stocking densities and productio n levels increase; however; much of the feed is not assimilated into s hrimp tissue, but instead becomes dissolved and particulate waste that may be discharged as shrimp pond water is exchanged or drained for ha rvesting Such nutrient enrichment of coastal waters by aquaculture eff luents may be a significant concern in some areas. In the hypothetical intensive shrimp farm described here, water is recycled within the sy stem, with discharges only to release excess water from precipitation or to maintain acceptable salinity. Water is not discharged at harvest but is held over winter between crops and then used again the next gr owing season. The primary crop of shrimp is co-cultured with oysters a nd herbivorous fish (mullet) to enhance solids removal and deposition and create other cash crops. The amount of nitrogen provided as feed i s reduced by using feeds with less protein and better feed management The farm plan is modular with each 4-ha module consisting of: (1) thre e 1.0-ha shrimp monoculture ponds; (2) one 1.0-ha oyster-mullet polycu lture and wafer treatment pond; (3) a small phytoplankton inoculation pond; (4) a solids settling basin; (5) sludge drying beds; and (6) upl and use of pond sludge to improve agricultural land. The system is des igned to produce 40 mt of whole shrimp, 7 mt of mullet, and approximat ely 0.5 million single select crysters/modtrle/year.