The modules are 24m x 24m, with the first two being set up as nurseries to introduce the fingerlings. Each cage (24 x 24) is divided into four smaller cages by walkways. As the fish grow they swim through a transfer gate to larger cages. These nets are smaller mesh and not so deep. As they mature, the fingerlings go from cage to cage with larger mesh and deeper nets, thus maintaining a steady stocking density. Suppose that 1,000 fingerlings weigh 30 grams each: in a few days they will weigh 60 grams. By the time they weigh two or three kilos they are down at the other end of the unit; the nets are deeper but the stocking density is maintained.
Type of Fish
Depending on the speed at which you want to get a fish farm up and self-funding, you might consider Tilapia as your first option (Nile perch). The best option for Vietnam might be the Taiwan Red tilapia but there are a couple of others suited to the tropics. Further down the line you could consider Barramundi: they are a high value fish but take longer to grow.
Tilapia have less value but their ease to grow and the ability to stock them very densely per cubic meter is a winner. For instance, salmon are stocked at 8-14 kilograms per cubic meter of water, Barramundi about 12-18 kg/m3 and Tilapia 30-40kg/m3 . They only need three things: 1. clean water, 2. food and 3. light. They grow extremely fast for the first 40 weeks then they slow, however, by this time they have reached plate size. This fish is accepted all around the world and especially in America where the price is much higher.
The Market
- The cost of Tilapia in USA was US$7.72 per kilo in 2015 and has been growing by 4.8% per year.
- Cost of feed could be .35 to .80 cents per kg depending on where the fish are in their growth cycle.
- Another high value market to look at is live fish sales. Boats from Japan and China travel the seas picking up live fish in well boats and the return is fairly high.