Shrimp Aquaculture in Philippines

The Philippines has long been practising brackishwater aquaculture, in which milkfish was the primary species being cultured using the original extensive system. Shrimps were an incidental species in brackishwater fishponds before the 1980s.

The switch from traditional extensive systems to intensive shrimp monoculture, which began in the 1970s, triggered a significant increase in exports. From the traditional extensive and semi-intensive systems, the adoption of the intensive culture technique from Taiwan using small concrete ponds, high stocking densities, intensive feeding, water aeration, pumping in of fresh and sea water to facilitate water management, was promoted by the government and the private sector.

As the export industry grew, businesses rather than locals became dominant in the shrimp culture industry. Production rose from 1,804 metric tons (mt)in 1982, to 75,996 mt in 1992.

Exports of shrimp, mainly to Japan, the US and Europe, peaked during this period. Only about a quarter of the total production, was consumed locally.

After 1992, however, the industry has been plagued with problems of environmental pollution and degradation, resulting in poor production and mass mortality due to diseases. Areas previously practising intensive farming of shrimps have ceased operation. It is estimated that out of the 47,776 hectares (ha)of shrimp farms in 1991 only about 20,000 ha are now in operation. Only those areas practising extensive and semi-intensive farming continue to operate.

The growth of shrimp culture has contributed significantly to mangrove destruction. In the Philippines most of the brackish water ponds were constructed in mangrove areas. The mangrove forest area declined from 450,000 ha in 1920 to just 149,000 ha in 1988. While extensive shrimp farming before the 1970s destroyed most of the mangroves, the boom of the 1980s resulted in another 30,000 ha of shrimp monoculture ponds being constructed. With the destruction of mangroves, the vulnerability of coastal areas in the country to natural disasters,

such as the typhoon in November 1990 that devastated shrimp farms in central Philippines, has

increased.

The destruction of mangroves has also affected coastal fisheries, and has marginalised small-scale traditional fishers. The negative impacts of shrimp culture have been particularly severe in Negros Occidental Province, where, in some villages, people do not even have enough water for household use, due to the contamination and over-exploitation of ground water supplies by shrimp farmers. Orchards have died and rice farms have become infertile throughout much of the area as a direct result of intensive shrimp farming.

Other significant environmental problems resulting from intensive shrimp farming include organic matter overloading, nutrient enrichment and eutrophication, chemical toxicity, development of antibiotic resistance, displacement of native species, and the spread of disease through species introductions, soil and water salinisation, and land subsidence.

Despite the grave social and environmental problems resulting form shrimp farming, the Philippines and other Asian countries have received a high level of financial support from international financial institutions like the World Bank, the Asian Development Bank and the IBRD.

The Filipino Government, in response to the evident problems caused by intensive shrimp culture, is now trying to promote semi-intensive culture of shrimp using environment-friendly technology. They are also trying to promote integrated coastal area management schemes, and to formulate and implement regulations to control aspects such as the indiscriminate discharge of effluents and wastes by fishponds.