Environment-friendly aquaculture

Aquaculture is the farming of aquatic animals (fishes, shrimps, crabs, shells) and plants. It may involve seed production (hatchery-nursery) and grow-out production phases. It may be undertaken in land-based or water-based enclosures, either in fresh, brackish and marine waters.

In the Philippines, aquaculture has steadily increased its contribution to total fisheries production from only 13.7 percent in 1978 to 25.3 percent in 1987. Milkfish and tilapia farming has contributed significantly to the domestic fish supply and shrimp farming to export earnings.

While aquaculture can have considerable economic benefits, it can also have adverse environmental (socioeconomic and ecological) effects:

· Poor farming communities become poorer, with more of the benefits accruing to those already with money.

· Former natural habitats become fragmented.

· Soil, water and landscape qualities deteriorate.

· Animal and plant diversities decline.

· Harmful chemicals and microbes get into common waters.

However, this needs not be the case if aquaculture facilities are properly planned, operated, managed and monitored. Some actions aquaculture practitioners and the general public (through advocacy) can take for environment-friendly aquaculture are as follows:

· Go for sustainable, low-input, high-yield aquaculture systems.

Integrated agriculture-aquaculture systems (fish-rice, fish-livestock, etc.).

Semi-intensive farming (with less feed, fertilizer and pesticides inputs) rather than intensive farming.

Seafarming (seaweed farms, oyster/mussel culture, fish cages in open marine waters) rather than in inland waters and mangrove swamps.

Polyculture (milk-fish with shrimp, crab with seabass), rather than single-species culture.

· Select native species that feed low on the food chain (plant feeders), grow fast, breed naturally, are disease-resistant and hardy. This obviates the need for feeds and chemicals, such as fertilizers, pesticides, antibiotics and hormones. Exotic species (which may carry diseases and pests or displace local populations) must not be farmed unless they have gone through a very stringent quarantine.

· Select proper sites for aquaculture facilities to minimize the environmental impact. Consider other uses and users of the sites. Go for sustainable and equitable development.

· Conduct a thorough, honest socioeconomic and ecological impact assessment before proceeding with the implementation. Ask who benefits or profits and who loses in terms of jobs and income; how much land, energy, water, labor and other resources are diverted from other uses; how the wastes will affect the surrounding community.

· Practice and promote proper pond/cage/tank preparation and management. Keep buffer strips of mangroves or other trees around the ponds to minimize erosion. Minimize pond tillage that exposes acid soils. If feeds are necessary, use the appropriate kind and amount.

· Oppose the clearing of mangrove forests, wetlands and other virgin areas for new ponds. Replant mangroves or other trees along the dikes of ponds.

· Oppose stream modification and massive ground water extraction for aquaculture. They can lead to flooding, land subsidence (sinking) and reduced water supply.

· Keep freshwater fishponds weed-free and well-stocked to control mosquitoes. Be aware of the waterborne diseases present in the locality and assess whether ponds significantly add to the risks of contraction by farm workers, fish handlers and consumers. Seek professional advice from public health workers.

· Support the ban of the production, sale and use of antibiotics, hormones and pesticides in food production.

· Clean (properly treat) the waste water from aquaculture facilities to prevent adverse effects on other water users. In shrimp farms, set aside some filter ponds stocked with filter-feeding mussels and nutrient consuming seaweeds. Route the waste water (with the excess feeds and other wastes) through the filter pond before disposal into coastal waters. Since antibiotics, pesticides and hormones cannot be removed from waste waters, do not use these chemicals.

Ideas for Action:

A Technology Information Kit November 23 - 28, 1992