Increasing extensive shrimp farm productivity by managing algae and improving water circulation at Long Khanh Commune, Duyen Hai District, Tra Vinh Province, Viet Nam

Objectives

The project aims to demonstrate inexpensive ways to increase extensive shrimp farm productivity by managing algae and improving water circulation for more sustainable practices on extensive shrimp farming. 

Background

In recent years, many households that practice extensive shrimp farming in Long Khanh commune of Duyen Hai district, Tra Vinh province have limited taking water into their ponds for fear of wastewater and shrimp diseases discharged from industrial shrimp ponds. As a result, the water becomes stagnant and creates favourable conditions for algae to grow and pollute the ponds further. Therefore it is needed that a model of effective algae management and water circulation is built to help extensive shrimp farmers. 

Target beneficiaries

• 08 households will directly participate in demonstration plots
• 75 people participate in disseminate workshop

Outputs

• 08 extensive shrimp ponds are designed and adjusted for better water circulation
• Training on extensive shrimp farming combined algae management.
• 300 copies of guideline of extensive shrimp farming and combined algae management
• Adoption rate increase by 20% 

Accomplishments and challenges

The water exchange was improved and adjusted in all eight demonstration locations. The environmental parameters (BOD, NO3^-, PO4^3-, pH, etc.) were better than before and up to standards for aquaculture.

Shrimp seeds in hatcheries of all eight demonstration locations grew well (performance gained 70-90% after 20 days of breeding/hatching), which increased the efficiency by 6-20%.

300 copies of the handbook describing the model of combined shrimp farming and algal management were delivered to the households in the project area. 75 representative households attended training workshops and learnt farming techniques.

The project has contributed to the local sustainable development through efficient aquaculture, rational use of local land and water resources and contributed to resilience to and mitigation of climate change.

The successful model has helped local women have more jobs through exploiting added values of algae: using algae to process aquaculture feed, livestock feed and make fertilizer for crops.

The project has also contributed to changing the awareness of sustainable aquaculture and rational exploitation and use of local resources.

Contributions to cross-cutting themes

• Climate change adaptation

Lessons Learned

In the project management, the close collaboration between the staff of the Institute of Tropical Biology, people in Tan Khanh Hamlet, Khanh Vinh - Long Khanh Commune and the local authorities made great contribution to the smooth operation of the project and the obtainment of the results as expected.

When gathering background information relating to aquaculture from people, there should be more detailed questions to assess the accuracy of the information received. (For example, people often give estimates of yields, so questions about total earnings, prices, the time of harvest should be included).

For near-poor households who do not have the counterpart money required for the project, the counterpart labor is needed, because it is difficult to mobilize capital from these households.

The Department of Agriculture and Rural Development needs to zone the farming area and generally manage water resources in a coherent way, thereby manage and control diseases for the whole area more effectively.