Thursday, May 29, 2014

Freshwater Farming: Business and Hobby

Dr Abe V Rotor
Living with Nature School on Blog
Paaralang Bayan sa Himpapawid with Ms Melly C Tenorio
738 DZRB AM Band, 8 to 9 evening class, Monday to Friday

Plapla, all-male tilapia through sex hormone treatment.

There are three ways freshwater fish can be cultured as pastime or business.

1. Family fishpond
2. Palay-isdaan (rice-fish culture)
3. Cage culture

Part 1 - Family Fishpond

A family fishpond is an enlarged version of a home aquarium. The requirements in taking care of the fish are basically the same – clean water, good aeration, sufficient feeds, suitable temperature range, absence of pollution – and above all, TLC (tender, love and care).

No wonder the aquarium is a source of joy to adults and children alike. And the ambiance it lends to the environment is therapeutic, especially for one who comes home after a hard day’s work. It brings the whole family together on weekends.

I missed my outdoor sports as a fisherman-enthusiast when I moved to the city some years back. To compensate for it I built a garden pond with a dimension, 4 meters long, 2 meters wide and one meter deep, and stocked it with some two dozen juvenile catfish for fattening. Three months after and the fish were ready for harvesting, I would gather the family into a backyard picnic, and how we all enjoyed inihaw na hito.

If you are living in the province, the conditions there are better. These are the things you can do.

1. You can enlarge the size of the pond so that you can raise fish for the family and the neighborhood. You can have separate ponds for tilapia, hito, gurami – or bangus, if you are living within the estuary.

2. Make use of the natural topography of the land using the lowest part (basin) as the pond. Be sure you have sufficient running water. If not, have a deep well ready to augment water supply. To reduce loss of water through leaching, compact the bottom with clay. There are now plastic sheets used as fishpond lining.

3. Stock your fishpond with fish of the same kind and size so that they will grow evenly. When  raising tilapia, avoid overcrowding. Tilapia reproduces very fast. Stocking with all male tilapia is important in obtaining even and fast growth.

4. It is cheaper to formulate your own feeds than to depend on expensive commercial feeds, especially where rice bran and fishmeal are readily available. Kitchen scraps, such as fish and  poultry entrails, are a good feed supplement. Avoid excess feed as this is likely to accumulate and decompose.

5. A pond has good natural food supply if it is rich in plankton. The color of the water is usually bright green. Plankton organisms are microscopic and highly diverse. Phytoplankton (mostly green algae) are photosynthetic, and together with the zooplankton (microscopic animals called protists), form the base of a complex food web, on which the fish ultimately obtain their nourishment. To increase plankton population fish farmers use appreciable amounts of nitrogenous and complete (NPK) fertilizer.

Care should be observed not to induce overproduction of plankton because this causes algal bloom. Plankton decomposition, exacerbated by over feeding, increases produces hydrogen sulfide and methane gas, increases carbon dioxide level, and reduces dissolved oxygen. Foul odor forewarns of disaster. Replace the foul water immediately with fresh water.

6. A fence made of nylon net is recommended during the flood season, especially in low-lying areas. This will also serve as a rail guard for the safety of children and pets.

7. For intermittent ponds, harvesting is done when water supply is low. This allows the fishpond to dry up, ready for the next season. In farming we call this fallowing or resting the land. This is true also with fishponds. For fishponds with sufficient water throughout the year, harvesting is done with lift net, selecting only the big ones, and allowing the small ones to grow. For Nile tilapia (T. nilotica), three pieces make a kilo is ideal, for hito, four pieces.


Part 2: Palay-isdaan (Rice-Fish Farming)

This technology is indigenous. What we call palay-isdaan is an innovation of a traditional way of raising fish and other freshwater organisms while the rice plant is growing in the field during the rainy season.

Many wildlife species are found in ricefields as their natural habitat. These are commonly freshwater fish like hito, dalag, gurami, martiniko, and lately, since the fifties, tilapia. Then we have ulang (freshwater lobsters), shrimps, kuhol, suso’, and tulya. Strong rains release these organisms from their hibernation, usually in carabao wallows, ponds, and river basins – or in mud where they were ensconced during summer.

The ricefields become one huge lake at the peak of the rainy season, and as the water subsides, these organisms are trapped in the paddies. Farmers pick them up for food, which is indeed a good source of protein for his family. Many find it a sport hunting them, while others find ways of protecting them until they reach maturity. The latter is the basis of palay-isdaan technology, which has these features.

1. The dike (pilapil) must be strong and high enough to prevent the fish to escape. To do this, trenches are dug around the rice field like a moat, two meter wide and one-half meter deep. The soil material is used to rebuild the dike.

2. Another model is to build a wide trench, 3 to 4 meters wide and one-half meter deep, running through the center of the rice paddy. This is usually done in low-lying areas where the water stays much longer. The trench serves as a natural trap for the fish as the surrounding water subsides.

3. A third model is recommended for irrigated areas where the rice field is managed like a fishpond. Here the farmer selects the fish he wants to grow, provides them with supplemental feeds, and gives attention more than what the other two models require. A commercial model would mean converting 30 percent of the total area into trenches.
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Palay-isdaan is a revival of a virtually lost art and indigenous industry. Since the late fifties, the introduction pesticides and chemical fertilizers and their rampant use decimated wildlife in ricefields. As a rule therefore, unless the ricefields are free of these poisons, palay-isdaan will never succeed.
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4. Because it takes time for the fish to grow to maturity it is advisable to plant traditional rice varieties which mature in 110 to 130 days. But this is feasible only where the rainy season is long and water supply is readily available. Traditional varieties generally do not need chemical spraying and fertilization - hence, safe to the fish.

Well-managed rice-fish farms in Central Luzon and other parts of the country can yield as much as 200 kg of tilapia per hectare. At P70 per kilo at source, the gross value is P14,000. While this gives 13 percent additional income, the farmer should consider a reduction in rice yield by at least 5 percent. Still palay-isdaan gives more income than rice monoculture.

Irrigated areas can have two fish crops a year, but this is not advisable because of the high cost of irrigation. Besides, it is virtually impossible to grow palagad rice (summer crop) without heavy dependence on chemical pesticides and fertilizers.

Whatever is our reason to engage in fishing, hobby or business, there is something more that we derive out of it. Let me count the ways. Fresh fish, added income, aesthetic value, clean air, sunshine, good exercise, peace of mind, companionship with nature, good health – and the thought that we are close to the Greatest Fisherman who ever lived. x X x

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