AQUACULTURE: Vannamei, a vital export commodity
Text and Photos By JHEILA Y. DIZON
FARMED prawn is a vital export commodity for the stakeholders in the Philippines.
Known as vannamei, it is a variety of prawn of the eastern Pacific Ocean which is commonly caught or farmed for food.
While production of the local industry is reportedly increasing, it is unfortunate that it is experiencing a setback due to the prevalence of certain viral diseases affecting the vannamei variety.
But despite the problems confronting the sector, production of vannamei in the country is reportedly growing.
Due to this development, several industry players have started to craft their own methods to reduce or prevent the occurrence of diseases, and to improve yield through sound management practices.
Since prawn is an important aquaculture commodity, the prawn farm of Ricky Sun in Manapla, Negros Occidental adopted sound management practices and developed its own technologies to boost the local production.
For the feed conversion ratio, a modified feeding schedule has been designed for his farm to minimize feed wastage and lower production cost.
After all, the vannamei variety is very efficient at utilizing the natural productivity of the ponds.
The prawn farm of Sun uses the Tiger L. vannamei prawn feed, which is supplemented by Amino Plus Foliar Fertilizer (APFF).
Following this development, the farm has the potential to achieve a harvest of approximately 20 tons per half hectare pond.
The Tiger L. vannamei prawn feeds and the organic APFF are distributed in the Philippines by Global Green Organic Fertilizer, Inc.
It is expected that the different modifications and technologies developed by the farm management will help boost the local industry.
Even the United Nations’ Food and Agriculture Organization (FAO) has said that commercial culture of the mentioned species in several areas showed a rapidly increasing trend, adding that Asia has seen a phenomenal increase in the production of vannamei.
But due to fears on theentry of exotic diseases, many Asian countries have been reluctant to promote vannamei farming, where its culture remains confined to experimental testing only in several, according to FAO.
It can be noted that some countries freely permit its commercial culture but have official restrictions, so that only quality and safe broodstock may be imported.
If the harvest is directly sold to exporters, specialized teams for harvesting and handling are commonly tapped to maintain quality.
Similarly, other countries have strict quarantine laws to prevent importation of exotic pathogens with new stocks.
According to the FAO, hatchery systems may range from specialized, small, unsophisticated, often inland, backyard hatcheries to large, sophisticated and environmentally controlled installations, together with maturation units, where water is regularly exchanged to maintain good environmental conditions.
Feeding normally consists of live food (like planktons), supplemented by micro-encapsulated, liquid or dry formulated diets.
At the Manapla prawn farm,the ponds can be completely drained, dried, and prepared before each stocking.
This culture system is common in Asia and some other farms that are trying to increase productivity. Ponds are often earthen, but liners can also be utilized to reduce erosion and enhance water quality.
Ponds are generally small, ranging from 0.1 to 1-hectare, and water depth is usually around 1.5-meter.
Meanwhile, the potential of the local industry remains bright, and it can create direct and indirect jobs in a certain region, and provide an opportunity for rural development.
But to attain this, it is important for shrimp farmers to practice responsible aquaculture by purchasing seed from authorized hatcheries only, implementing strict biosecurity protocols and following strict quarantine measures and best management practices in culture systems.
These safeguards are now being applied at the various farms of Ricky Sun in Negros Occidental.
Partial harvesting is also common in many parts of Asian after the first 3 months, and at the Manapla farm, the prawns are simply harvested using large scoop nets when required for processing.
After sorting, prawns are weighed and immediately dispatched using iced water to attain a prescribed temperature.
Following the harvesting process, the prawns are forwarded to the releasing area by using pulleys to ensure safety at the farm.
On the other hand, the availability of safe broodstock provides a means of avoiding diseases, although biosecurity procedures are also important, including: thorough drying/scraping of pond bottoms between cycles; reducing water exchange and fine screening of any inlet water; use of bird netting; and, placing barriers around the ponds.
Once viruses enter the ponds, FAO said there are no chemicals or drugs available to treat the infections, but good management of pond, water, feed and the health status of stocks can reduce virulence.
Because of this, farmers are becoming aware of the growing need to farm shrimp or prawn in a responsible, traceable and low impact manner, which can enhance biosecurity, help protect the environment and produce shrimp in a cost efficient manner.
In order to maintain the growth of local industry, domestic consumption should also be encouraged to supplement the erratic export markets.
Due to the rapid expansion and increasing awareness of the negative impacts of shrimp farming practices on the environment and its own production, many producing countries are now starting to create efforts to comply with the concept of responsible aquaculture as detailed in Article 9 of the FAO Code of Conduct for Responsible Fisheries.
The formulation and adoption of Good Aquaculture Practices is gaining prevalence to enhance biosecurity, increase cost efficiency, reduce chemical residues and increase traceability.
It is expected that the various technologies developed from the program will help in boosting the industry in the country.
Quoting experts from other countries, even the aquaculturemag.com has said that to achieve sustainability, it is necessary to increase and create more brood stock rearing centers.
Aeration is vital for better water circulation and oxygenation.
It is also imperative to prevent the operation of unauthorized hatcheries and rearing centers, where it is fundamental to generate protocols and guidelines for probiotic use in soil, water and feed, as well as promote the implementation of best management practices and biosecurity in the shrimp farms of the country.