Implementation Status of the Research Components (March - August 2002)

Component 1 - Profile of Key Aquaculture Technologies and Fishing Practices

Sri Lanka

Freshwater Aquaculture

Sri Lanka has vast inland water resources and coastal areas available for aquaculture. Although Sri Lanka is reported to have the highest ratio of freshwater bodies to land in the world (22.8 ha per km2 of land), the share of freshwater aquaculture production in total fish production is as low as 3%. About 50 000 seasonal tanks with an area of about 100 000 ha are available. These water bodies are constructed to hold water for dry season paddy cultivation, and at least half can be used for aquaculture. Other freshwater resources include large irrigation reservoirs (70 850 ha), minor irrigation reservoirs (39 271 ha), Mahaweli reservoirs (22 970 ha), medium irrigation reservoirs (17 004 ha), upland reservoirs and flood lakes.

The freshwater finfish species cultured are tilapia (Nile, red, Mozambique, blue and genetically improved farmed tilapia, GIFT), Chinese carps, Indian carps and the indigenous species Labeo dussumieri. Carnivorous fish are not cultured due to high costs of production.

The country does not have a tradition of fish culture either in freshwater or brackish-water. The government started a subsidy scheme to encourage pond fish culture in 1981 and over 4 000 farmers benefited. With a stocking density of 5 000 - 7 000 fingerlings perha, a 2 000 kg.ha^-1 yield was achieved after 6 - 8 months. Species included mrigal, common carps, bighead, silver carp, rohu and grass carps. Tank culture requires feed and fertilizer such as cow dung and decaying plant matter, which provide sufficient nutrients for the growth of fish. By increasing the stocking densities and with additional inputs, an average production of 2 000 kg.ha^-1 could be achieved.

Brackish-water/marine aquaculture.

Sri Lanka is endowed with 120 000 ha of brackish-water resources. Brackish-water aquaculture technologies are limited, although some culture species are undergoing experimental trials. These include the culture of marine seabass and grouper in cages, mud crabs and molten water crabs in concrete tanks, and mollusk culture in cages.

Capture fisheries

In Sri Lanka fish resources can be categorized into three major groups, namely small pelagic fish, large pelagic fish and demersal fish. Small pelagics contribute around 80% of the total production and the other 20% consists of large pelagics and demersals. The coastal inshore waters produce over 60 000 t of small pelagic fish (sardines, anchovy, herrings etc) and nearly 30 000 t of demersal finfish (snappers, breams, groupers, skates, rays etc). The crustacean catch consists of about 6 000 t of shrimp and about 1 000 t of lobsters from inshore waters. The main fishing gear used are small meshed gillnets, large meshed drift gillnet, bottom set gillnets, bottom long lines, tuna long line, beach seine, hand line and traps. The main gear used for offshore fishing are pole and line, troll, trammel nets, trawl, ring net and purse seine. There were 18 254 vessels operating in 1998: 8 625 non-mechanized boats, 863 outboard engine traditional boats, 6 600 outboard engine FRP boats, 853 inboard engine day boats and 1 313 inboard engine multi-day boats.