Success Stories In Asian Aquaculture - Library - Network of ...

104 U.S. Amarasinghe and T.T.T. Nguyen6.1 IntroductionSri Lanka (5º55 ¢ –9º55 ¢ N; 79º42 ¢ –81º52 ¢ E) is a continental island of about65,621 km 2 in monsoonal Asia with rich water resources. There are 103 perennialrivers in Sri Lanka, most of which run radially from the central highland area anddrain into the western, southern, and eastern coasts. These river basins drain over90% of the land area. Floodplains, lagoons, and estuaries also form natural inlandwater resources of the island (NSF 2000) . There are no natural lakes in Sri Lanka,but the country has a multitude of reservoirs, including ancient irrigation reservoirsand recently constructed multipurpose reservoirs (De Silva 1988 ; Fernando 1993) .Almost all of these reservoirs are situated in the zone of the country receiving lessthan 187 cm annual precipitation (Fig. 6.1 ). This zone is located within the lowestpeneplain of the island, and covers approximately 66% of the total land area of thecountry, which holds 33% of the country’s population. Over 90% of the rural populationis directly involved in farming and the peasant community is characterizedby acute poverty and malnutrition (De Alwis 1983) .The inland fishery of Sri Lanka has been essentially a capture fishery fromperennial reservoirs (major and medium-scale irrigation reservoirs; Table 6.1 ).However, most small-sized (