Shrimp Farming and the Environment - Library

TABLE 4. OVERVIEW OF SHRIMP FARMING IN MAJOR PRODUCING NATIONS: 1996Country No. of Total area Production Extensive SemiintensiveIntensivefarms (ha) (head-on, MT)Belize 6 600 2,000 0% 90% 10%Costa Rica 4 800 1,000 0% 100% 0%Ecuador 1,200 130,000 120,000 60% 40% 0%Honduras 55 12,000 10,000 5% 95% 0%Mexico 240 14,000 12,000 25% 65% 10%Nicaragua 20 4,000 3,000 0% 100% 0%Peru 40 3,000 5,000 5% 90% 5%USA 30 700 1,300 0% 80% 20%Venezuela 7 800 2,000 0% 100% 0%Australia 33 400 1,700 0% 20% 80%Bangladesh 13,000 140,000 35,000 90% 10% 0%China 6,000 120,000 80,000 10% 85% 5%India 10,000 200,000 70,000 60% 35% 5%Indonesia 60,000 350,000 90,000 70% 15% 15%Malaysia 400 4,000 4,000 40% 50% 10%Philippines 1,000 60,000 4,000 40% 40% 20%Sri Lanka 900 2,500 2,000 10% 20% 70%Thailand 16,000 70,000 160,000 5% 15% 80%Vietnam 2,000 200,000 30,000 80% 15% 5%Total 110,935 1,312,800 633,000Source: Rosenberry 1996. NB: Figures are approximate only and do not include all shrimp farming nations.Ecuador is making the transition from extensive to semi-intensive farming. Northern China pursues itsown model of semi-intensive farming. Japan; Taiwan, Republic of China; the U.S.; Australia; Thailand;Sri Lanka; and some European countries concentrate on intensive shrimp farming, and intensive farmsoccur in all major shrimp farming areas of the world, but especially in Thailand, Sri Lanka, andAustralia.ScaleShrimp farms vary enormously in scale, in terms of both area used and production. Small farms inSoutheast Asia may be half a hectare or less, while semi-intensive farms in South and Central Americamay cover thousands of hectares. Small-scale operations are characterized by low investments and aninterplay with other operators, often more sophisticated and larger-scale, in their vicinity.Small farms are often thought to have limited impact on the environment. This is misleading; thecumulative impact of a large number of contiguous small farms (or those in close proximity) can be asenvironmentally damaging, or more so, than single large-scale developments. It is therefore importantto take into account the density of development, especially in relation to carrying capacity, whenconsidering the environmental impact of aquaculture.The procurement of post-larvae (PL) for larger operations is often undertaken by small-scale operators,sometimes from the wild-capture fishery. The danger involved in such operations is that the small-scaleoperator often lacks the ability to take on responsibility for this ecosystem because of a poor economicsituation and lack of training. Small operators therefore tend to focus on short-term survival of theirown operations at the expense of the environment, even when they understand the local ecosystems.Thus, such operations tend to be detrimental to the environment, and particularly to the sustainability ofboth shrimp farming and capture fisheries.Summary and conclusionsA wide range of shrimp farming technologies, production systems, and scale of enterprise are foundthroughout the world, from highly extensive systems based on passive stocking and little if anyfertilizer or feed inputs, to highly intensive systems using high stocking densities, formulated feeds,and intensive aeration. They may be located in marine, brackish, and even inland waters, but typicallyuse earthen ponds. Although the use of hatchery-produced seed is increasingly common, almost allhatcheries still depend on wild broodstock.18