Vietnam is one of Asian leaders in aquaculture production and has experienced extraordinary growth rates in recent years, producing annually 3.2 million tons of aquaculture products. However, Vietnamese aquaculture is coping with many problems, of which disease outbreaks are among the most important concerns. Chemicals or antibiotics are applied quite extensively to control pathogens, sometimes under improper management. The application of these chemicals brings a lot of disadvantages such as their bioconcentration in cultivated organisms, human carryover, pollution, development of antibiotic resistant bacteria, destabilization of helpful bacterial populations in environment and immunosuppression in fish. Nowadays, more environmental-friendly prophylactic and preventive solutions are required and natural bio-active products are searched for to enhance the immune system and health status of cultivated animals.
However, despite a high diversity of wild plants distributed in the different eco-regions of Vietnam and the interest of a large proportion of aquaculture farmers to use alternatives to antibiotics, the actual use of natural derived products in aquaculture is not yet very popular in the country, due to a lack of knowledge regarding the existence of such bio-active products and the demonstration of their efficiency on fish.
In this project, chemical and biological technologies will help to develop effective methods for extraction, characterization, bioactivity evaluation and formulation of high-value natural derived materials for aquaculture production at affordable prices for farmers, the specific objective being to provide to key stakeholders a list of useful plant extracts with related recommendations as a feasible alternative to the overuse of chemicals in Vietnamese aquaculture. The fish species on which the compounds will be tested have been selected in order to cover two complementary fish markets of importance for Vietnam: the snakehead as a model species for the local market, and the striped catfish “pangasius” as the main exported fish.
The response strategy will be based on:
- the inventory and collection of a set of wild plants from different locations of Vietnam, that could potentially contain bio-active compounds of interest as “nutraceuticals” to be used as feed additives for stimulating the fish immune system and/or modifying its microbial flora;
- the evaluation of natural bio-active product efficiency in fish health management, including the sanitary and nutritional quality of fish flesh during the rearing phase or post-harvest and the validation of selected bio-active products in selected fish farms under different realistic culture scenarios in collaboration with Vietnamese fish farmers;
- the elaboration of recommendations, based on economic and technical feasibility analysis, on how to use the extracts or how to develop their use;
- the dissemination of existing and acquired knowledge to relevant stakeholders (scientists, extension services of the competent ministries, fish and plant extract producers, fish feed companies);
- the strengthening of local capacities to conduct further research, including the isolation and structure determination of molecules from selected plant extracts, in order to support the use of alternatives to chemicals in aquaculture.