Basa is one of the most exported fish species in the world. There is a huge market in USA, Europe, Asia and Australia. This fish is very popular because the price is very low and the flesh is white with a very low flavour so it doesn’t present any “Fishy taste”. From a technical point of view, Basa also called Panga (from thew latin name Pangasius) in Europe or swai in Asia, presents the particularity to be able to be grown in huge density and resist to very low oxygen concentration. The cost of growing 1 kilogram of basa is therefore very low, it is one of the cheapest farmed fish species in the world. In Aquaculture it is farmed mainly in Asia using different techniques. The largest farms for exportation are using ponds while the smallest farms producing for the local market are using cages on floating rafts directly into the river.
We went visiting a Vietnamese farm situated into the Mekong Delta. This specific farm is equipped with 11 huge ponds. One of them contains 700 tons of fish of average 800g each. This is 875000 fish per pond! The scale of this farm is impressive, so much that it takes 10 days to harvest the whole pond. Only 15 workers are able to manage the whole production of this farm. The Vietnamese aquaculture industry remains very manual comparing to European fish farming.
Those fish are fed twice a day with 10 tons of food per day which corresponds to 1.4% of the total fish biomass per day.
Basa is a very interesting species to grow in Aquaponics even if it is recommended to remain lower in terms of density in order to avoid to stress the fish.
During the visit we had the opportunity to have a close look at the fish and could notice that most of the fins were damaged which shows that the fish are stressed due to the high density. In Aquaponics I would recommend a comfortable limit of 80 kg of fish per 1000L of fish tank.
After the visit of the farm we went visiting the processing factory. The slaughtering technique used here is the thermal choc. The fish are dipped into a very cold water and therefore their body temperature drops and they die. This technique is considered human and preserves the quality of the flesh as most bacteria species can’t develop at low temperature.
Finally I think it’s important to remind that most catfish on the market is soaked with water which means that during the processing of the fillets, they inject water into the fillet so it increase the weight of the product. Several chemical blends are used to soak the fish but STPP (Sodium TriPolyPhosophate) is the most commonly used as it link the added water to the protein of the fish. If you buy basa from your local supermarket you will realize that the fillets are almost transparent. You can see through due to the added water. If you grow basa in Aquaponics the quality of the flesh will be highly better than what you get from the market so go for it! J