Intensive Shrimp Culture

Under intensive and semi-intensive forms of shrimp aquaculture, feed, seed, water and energy are injected into closed (usually concrete)ponds. The ponds have a life span of between 5 and 10 years, after which time the exhaustion of the supply of clean fresh and seawater and the build-up of pond sediments and corrosion forces farmers to relocate.

Scores of new shrimp ponds have been constructed throughout Asia as the industry has grown. Lying in their wake, however, are the older abandoned ponds. Rough estimates, based on the assumption that intensive farms are viable for 5 years and semi-intensive farms for 20 years, indicate that approximately 150,000 hectares were abandoned worldwide between 1985 and 1995- Thailand abandoned an estimated 11,000 hectares, Ecuador abandoned 2,300 hectares, Indonesia, 800 hectares and India, 600 hectares. In 1994 alone, 20,000 hectares were

abandoned. If production rates remain constant, another 100,000 hectares will be abandoned by the year 2000. This will bring the total amount of land abandoned in 15 years to 250,000 hectares. This land, mostly mangrove swamps, will be totally unproductive. Meaningful regeneration might take 20 to 30 years.

These estimates are actually quite conservative. An increase in the dispersal of disease, along with pollution and the increasing density of aquaculture, is shortening the life span of ponds. In some countries, ponds have been abandoned after less than two years. But because the price of land is not high compared with other production expenses, the general tendency to abandon farms and start all over again persists. Researchers predict that 1.5 to 3 million metric tons of cultivated shrimp could be produced globally by the year 2000. If these production levels are attained, abandonment rates are bound to rise.