Clean shrimps after all
After a boom decade in the 1980s, world production of cultivated shrimp has fallen sharply due to intensive and polluting methods of cultivation, which encourage diseases (see Spore 82, page 4 & 5). Some say it would be best to stop such methods. But the question arises, what would happen to the shrimp farmers who have invested in the sector? In the Philippines, three new simpler methods are being tested which are less polluting. One method is to raise fish, preferably tilapia, in the shrimp ponds, in a netted-off area comprising ten per cent of the total area. This increases the amount of nitrogen in the water, which encourages the growth of less toxic micro-organisms than normal. Then air is pumped into the water through a series of pipes; this helps plankton to grow, and improves the shrimps diet; it also helps the water flow around, bringing in less polluted effluents from the edge towards the centre of the pond. There a central collector removes them regularly. The result: shrimps grow almost as fast as in the traditional intensive system, but their survival rate has risen from 70% to 85%, and the mangrove ponds are no longer asphyxiated. Southeast Asian Fisheries Development Center Aquaculture Department Tigbauan 5021 Iloilo, Philippines Fax: +63 33 335 10 08 Website: http://www.seafdec.org/ Email: devcom@aqd.seafdec.org.ph
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| Format: | News Item biblioteca |
| Language: | English |
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Technical Centre for Agricultural and Rural Cooperation
2000
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| Online Access: | https://hdl.handle.net/10568/46866 https://hdl.handle.net/10568/99590 |
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