Modified extensive pond culture of Litopenaeus vannamei for sustainable shrimp culture in the Philippines

The shrimp culture industry provides huge revenues to most aquaculture producing countries, but it is also beset with problems that hamper its sustainability. In the present study, we described a modified extensive pond culture method for white shrimp, Litopenaeus vannamei in the Philippines during the wet and dry months. One hectare earthen ponds were prepared and added with organic and/or inorganic fertilizers to stimulate natural food production. The ponds were stocked with L. vannamei postlarvae (PL) at a density of 4 PL m-2. A zero-water exchange system of pond management was done during the first two months of culture followed by a bi-weekly water exchange until harvest. No artificial feeding was given during the culture period, instead, the ponds were applied with inorganic fertilizer every month to ensure continuous supply of natural food. During the culture period, the shrimps appeared healthy and no disease outbreaks were observed. All the physico-chemical parameters of the water in the pond were within the optimum range required for shrimp farming and the phytoplankton population was predominantly green microalgae (Chlorophyta). The shrimps were harvested after 3 to 3.5 months of culture or when they reached an average body weight of 13-15 g, with moderate to high survival rates depending on the prevailing climatic conditions.