Technical approaches and aquaculture development alternatives

Tam Giang - Cau Hai lagoon systems covered over 22.000 ha, along coastal region from North to South of Thua Thien Hue with 70 km and more than 400.000 inhabitants are living around in lagoon systems. There are many livelihood activities as fishing, aquaculture and farming. Aquaculture systems are diversified: pond, net-closure in high and low tide systems and farmers and communities had to choose and select proper species and models for adaptation of the regions but they still have not successful, even they lost investment money and capital by environmental problems and uncorrected carrying capacity leading to diseases and low productions. Research results were showed the different technical approaches and aquaculture system alternatives for property aquaculture models in the regions. More than 267 aquaculture households of 15 communes in 5 districts that related to Tam Giang - Cau Hai lagoon were investigated and shown the figures on over 4000 ha of aquaculture water area of 33 communes: high/low tides of pond systems; cage culture in low tide systems; sandy shrimp culture system; integrated poly-culture and monoculture, while P. monodon was main species in all of systems and models. Efficiency of different alternatives were conducted in intensive of high tide was highest income, net income 100 - 700 mil. VND; semi-intensive of high tide-mono, 10 - 25 mil.; semi-intensive high tide-integrated poly-culture, 20 -40 mil.; semi-intensive-low tide-mono, 3 - 10 mil.; extensive-low tide-poly, 30 -50 mil.; marine water cage culture-poly, 25 - 35 mil., respectively. Effect of different species alternatives were on 267 households in differences, 26.99; 90.22; 221.13; 48.21, P < 0.01. The stock density and composition was conducted in differences of income and benefit for farmers, P < 0.05. Water control and management, dietary composition and feed processing, animal health management were effected on the income and benefit of aquaculture models, P < 0.01 and 0.001