Aquaculture has been significantly contributed to the development of many national economies. In Vietnam, aquaculture is an increasingly important part of the national economy. Vietnam has abundant natural resources that are favourable for the development of freshwater and coastal aquaculture. There are approximately 1.4 million ha of water surface that are suitable for aquaculture activities in Vietnam.Phu Yen province is located in South Central part of Vietnam with around 21.000 ha brackish water surface that is favourable for aquaculture activities, especially for coastal shrimp farming. Currentlly, coastal shrimp farming is considered as one of the main economic activities of the province.. Black tiger shrimp (Penaeus monodon) is being the main cultured species in coastal areas. The downstream area of Ban Thach river of Tuy Hoa district, Cu mong lagoon and Xuan Dai bay of Song Cau district are the main areas for intensive shrimp farming in coming years.Like many other coastal provinces in Vietnam, however, current activities of coastal shrimp farming in Phu Yen has been negatively impacted on natural ecosystem in coastal areas. Conversely, the outbreak of shrimp diseases resulting from environmental degradation as well as poor management of aquaculture have seriously affected the development of coastal shrimp farming activities in recent years. Sustainable shrimp farming remains a great challenge to the local governments and relevant agencies of Phu Yen province.The project VN/04/008 will be carried out in Tuy Hoa and Song Cau districts of Phu Yen province. The project has the following objectives:
1. Improving the biological wastewater treatment technique (using tilapia and seaweed as bioremediation species) for shrimp farms through carrying out experiments to determine the sizes, density of tilapia and of macroalge used in two biological treatment models.
2. Building two biological wastewater treatment models, using tilapia and seaweed to absorb waste nutrients discharged from grow-out shrimp ponds and the conversion of waste nutrients into the second crop for shrimp farms:Model 1 (applying for shrimp farms having treatment pond): Wastewater from grow-out shrimp ponds is syphoned into treatment pond rearing tilapia and seaweed.Model 2 (applying for shrimp farms without treatment pond): Tilapia is cultured in nets located inside grow-out shrimp ponds; and waste nutrients in shrimp ponds will be flowed into tilapia nets by paddle wheel.
3. Conducting monitoring and assessment on environmental and economic impact of these two models. Drawing lessons laerned and developing/compiling technical guidelines.
4. Enhancing understanding and knowledge, and building technical capcity for the local authorities, relevant agencies and communities so as to expand the model in the project areas.