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Super-intensive grow-out systems |
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Ultra-intensive marine shrimp culture systems are at the opposite end
of the spectrum from extensive culture. If
extensive culture ponds can be compared with naturally balanced
ecosystems, then ultra-intensive culture systems are comparable to
factories. Ultra-intensive culture "ponds" are little more than
culture vessels through which large amounts of materials and energy are
passed under the close attention of skilled attendants and business
managers. These shrimp factories produce large amounts of shrimp on very
small land areas. Ultra-intensive systems are impressive examples of
big-engineering achievements (Fast, 1992).
Super-intensive shrimp farming takes even greater control of the environment and can produce yields of 20,000 to 100,000 kilograms per hectare per year. Thus far, super-intensive shrimp farms have achieved only marginal success. Generally, they have problems with management, diseases, crop failures, water quality and the environment. Production levels above 10,000 kilograms per hectare per year are risky (Rosenberry, 1998). Ultra-intensive culture uses stocking densities in excess of 100 late-PL or juveniles/m2, with survival similar to intensive culture (80 to 90%). PL and juveniles are all hatchery reared. It is important that hatchery production meet or exceed the PL needs to keep the growout portion of the system fully stocked. Optimal production and a constant flow of product (shrimp) through the system depends on this. A nearly complete or complete diet is fed but may by supplemented with fresh feeds. Water exchange, which may include partial recirculation, usually exceeds 100%/day. Aeration may rely in part on pure oxygen injection (Fast, 1992). | |