The drawbacks of intensive milkfish farming
By Roberto Garcia
GENERALLY there are three methods of farming bangus in brackish water ponds: extensive wherein less than 2,000 fingerlings per hectare are stocked and depends entirely on natural feeding; semi-intensive where stocking ranges from 7,000 to 12,000 fish per hectare and a combination of natural and supplemental (commercial feeds) feeding; and intensive farming where stocking varies from 20,000 to 30,000 fish per hectare and regular feeding with commercial pellets only.
With the skyrocketing market price of bangus in Dagupan, perhaps fish farmers are encouraged to try intensive culture of the fish. But is this advisable?
According to studies conducted at the Southeast Asian Fisheries Development Center, intensive bangus farming not only requires higher stocking and feeding density but also higher levels of farm inputs. Therefore these additional expenses may cut through whatever increase in profits gained from the increase in fish production.
Furthermore, pond management, especially water exchange and dissolved oxygen maintenance, becomes more complicated with the use of water pumps and mechanical aerators. Otherwise fish kills can occur without the proper equipment to maintain the optimum water and soil quality. These two elements, water and bottom condition, actually limit the production capacity of the pond.
Another significant impact is the integrity of the environment and resources on which the bangus farming industry is dependent. The volume of waste and toxic chemicals discharged from intensive farms could dramatically alter the ecological balance that maintains good water and soil condition which, in turn, sustains aquaculture.
On the other hand, the economies of scale can bring down profits when prices go down due to oversupply of fish. This happened when fish pens abound in Dagupan rivers causing tons of fish unloaded regularly at the market.
So what would be the best and sustainable farming system appropriate in brackishwater ponds?
Aquaculture experts recommend the semi-intensive method with target production of three tons per hectare per year.