Application of solutions to improve water resources in aquaculture (07-12-2018)
In order to increase efficiency in aquaculture, the Department of Agriculture and Rural Development (DARD) of Nam Dinh province has launched a campaign to study technical innovations aimed at protecting water resources and limiting diseases in aquaculture.
Based on that, many technical solutions have been applied in the farming areas throughout the province. Two recommended groups of technical solutions are to filter water and to use micro-biological technology to ensure sustainable farming environment.
The technical solution of water recirculation using biological technology for fish ponds in Giao Xuan commune (Giao Thuy district) has brought high economic efficiency. Accordingly, the natural sea water is put into the reservoir pond and then transferred to the filtered pond outside (in ponds containing soil, sand, grass, algae); Then the water is passing through the underground filter, through the raw filtration and then the fine filtration of biological filter pond with the filtered made from dead coral. Finally, water is supplied into the pond. This solution has the advantage of simple operation; saving water resources; Decomposition of organic substances such as dead algae, toxins in the condensate water like NH3, H2S, NO2 and other heavy metals such as iron, chromium, lead; improving the immunity of aquatic animals in general and make the number of beneficial bacteria increase. Besides, it also inhibits and limits the pathogen development; stabilizes the pH of water and the water color as almost no algae grows; increasing dissolved oxygen in water to help fish develop. This technical solution is applicable in many production scale, many kinds of aquatic products as freshwater, brackish water, saltwater, etc. It helps save the water, simple operation, reduce labor, saving the cost of water treatment. This way has created a source of clean seafood, increasing commercial value, competitiveness of products in the market, suitable with aquaculture environment in the province.
The solution of using Biofloc technology in white leg shrimp farming by the author Tong Thi Luong, Sub-Department of Fisheries has been applied successfully in the white leg shrimp farming area of Hai Hau district. Biofloc are binder clusters consisting of diatoms, large algae, protozoa, dead organic particles, bacteria. The biofloc community consists of zooplankton and nematodes that provide excellent nutritional quality for shrimp and fish. Biofloc technology has shown a lot of advantages compared to other processes such as not using chemicals and antibiotics in the farming process and not causing negative impact on pond environment as well as surrounding environment. Particularly, the reuse of shrimp waste into Biofloc seeds is a natural feed for them so the amount of sludge in pond bottom is very low, reducing the risk of environmental pollution of pond water. The feed conversion ratio is low, thus reducing the cost of raising 10 to 20% compared to other feeding processes. The use of Biofloc technology in white shrimp culture solves the two main problems is the removal of nutrients metabolized into heterostructured biomass and used as food supplement in place for the object The system also helps prevent the entry of pathogens into ponds through water exchange.
In order to bring into play the technical solutions, the farmers need to invest in the pond system in accordance with the technical process; Ensure a treatment system before discharging the ponds into the environment and increasing the use of micro-biological technology, using bio-products to reduce waste from stools, excess food, residues chemicals, antibiotics in shrimp pond, from which, reduce the amount of waste to the natural environment.