What You Require To Establish A Small Fish Pond

Small-scale farmers netting a pond, Kawala, Mbala District

Prior to a farmer starting fish farming, there are a few fundamental contemplations to guarantee success. These include:

1. Design of the Pond

When choosing the pond site and configuration, there are a few variables to be considered. Portions of these are:

Source of water to fill the pond and how the same water will be brought to the pond:

The general rule is that the pond water inflow and outflow should measure up to the pond volume over the time of a month. On the off chance that the inflow is too low, water quality may experience the ill effects of oxygen exhaustion as well as collection of toxicants. In the event that the water surge is too high, a lot of valuable green growth might be flushed out from the pond. The water should keep the pond full all through the culture period. The pond should top off in under seven days. Place screens on pond deltas and outlets to keep out predators, creepy crawlies and undesirable fish and furthermore to hold the cultured fish.

Size, shape and pond depth:

Moderately shallow ponds are profitable. In any case, the shallow end ought to be no less than 0.5m deep to keep away from invasion by weeds and predation of the fish. The size and state of the pond can shift contingent upon the fish species, fish populace and the farmer’s preferences. It is important that on the off chance that you need to produce fingerlings, you will require even more small ponds while a food fish producer requires moderately large ponds.

Slope of the pond base:

The bottom of the pond must have an adequate slant for good drainage. A slant with a drop of 2cm for each 10m along the pond bottom is appropriate. On the off chance that the slant is excessively gentle, the pond will not be easily drained. In the event that the pond is excessively steep, it might be excessively shallow toward one side or too deep at the other end. Pond ought to be drainable.

Height, width and Slope of the dyke:

The perimeter and feeder streets are required for machines movement during construction and harvest. If you intend to drive on the dykes, assemble them no less than 3m wide to top and at the base.

Soil types:

Top soil is high in organic material and ought not to be used to construct pond dykes. Land ought to be made out of good quality soil, with practically no rock, shakes on the surface, or mixed in. Areas with rocky, gravelly, or sandy soil are not suitable for pond construction. Soil that will be used to build the dykes must contain no less than 20% clay so the finished pond will hold water throughout the growing period.

2. Fish Species suitable in Most African countries

There are three major fish species, which can do well in most African climatic conditions. They are Nile tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus) and Trout.

Tilapia

This is a warm water fish and is mainly cultured in fresh water environment. It thrives well in water temperature of between 20 to 35^oC. It attains sexual maturity at two months. Tilapia feeds lower in the food chain i.e. feeds mainly on phytoplankton, zooplankton and detritus.

Stocking rates range from two to six fingerlings/m², depending on the level of management. Male tilapia are known to grow almost twice as fast as females.

It is therefore preferable to stock only males (monosex culture) to achieve the fastest growth and reach market size in the shortest possible period, resulting in more proteins and profits. A major management problem of pond-cultured tilapia is excessive reproduction and the subsequent stunting of fish due to overcrowding.

Methods of controlling overpopulation include manual sexing of fish, use of sex-reversal hormones to produce all males, and use of predators.

The success of these methods may rest with how well a fish farmer understands the techniques.

Catfish

It grows in the same agro climatic regions as tilapia. The water temperatures of between 26 to 33^oC are ideal. It attains maturity at two years of age or at 200 to 500 grams. It feeds mainly on zooplanktons. Their stocking rate is 100 to 450 fry/m².

Catfish has a drawback of high mortality of fry especially during the first 14 days after eggs hatch.

Trout

It is a cold-water fish and it is best grown in high altitude regions where water is cooler. It is presently limited by availability of seeds and quality feeds in the country.

3. Pond Preparation for Stocking

The farmer should follow the procedure below to the latter when preparing the pond for stocking. These steps will help boost the productivity of the pond.

For an old pond, drain all water and allow it to dry for 14 days. Apply lime to the pond bottom and dyke slopes. Choose agricultural limestone (CaCO₃) for application in your fishpond.

Apply organic fertiliser in the pond before filling it with water. The most common examples of organic fertilisers are animal manures (from cattle, poultry, donkeys, rabbits, sheep and goats) and decaying plant matter, such as cut grasses.

4. Fill the pond with Water

Apply inorganic fertiliser in the pond after it has been filled. Apply DAP and UREA to your fishpond at the following rates: DAP: 2g/m²/week (or weekly applications of 15 tablespoons DAP for every 100m²) UREA: 3 g/m²/week (or weekly applications of 30 tablespoons urea for every 100m²).

Stock the pond 5 to 7 days after applying fertilizer on manure. Stock the pond in the morning or evening when the temperatures are low. When stocking, leave the bag carrying the fingerlings in the pond for about 10 minutes to allow its temperature to come close to that in the pond.

Allow some little pond water to get into the bag and then let the fish swim out into the pond at their own pace. Do not pour the fingerlings into the pond water. Stock at an average rate of 5 to 10 fingerlings per square metre of water surface.

Smallholder fish pond farmers in Luwingu, Northern Province, Zambia

5. Fish Feeds

There are various feeds that can be offered to the fish in the pond. Some commonly available feeds include:

• Meals
• Crumble
• Dry sinking pellets
• Moist sinking pellets
• Floating pellets

The feeds can be formulated to meet the body requirements of the fish species. This can be done as follows:

• Cotton seed cake — 37%
• Wheat bran — 57%
• Fresh shrimp — 6%
• Vitamin premix

Feed ingredients can be hand ground or a manual grinder can be used. It is important to adhere to the four fixes (4Fs) when feeding fish. These are:

• Fixed feed quality
• Fixed feed quantity
• Fixed feeding location
• Fixed feeding time

The fish should be fed between when the water temperatures and dissolved oxygen content are reasonably high and the fish are active. Feed three times a day at (9am, 1pm and 5pm) during fingerling and early post-fingerling stage (up to 2 months). Thereafter feed only at 9am and 5pm.

Observe your fish as they feed. When the feeding rate slows down, stop adding feed into the pond as the fish will have eaten enough.

Adding excess feed in the pond will lead to waste and pollution of pond water. Add manure or fertilizers to the pond after every two weeks to boost the growth of phytoplankton. Feed at a particular time and from the same place consistently.

6. Cropping and Harvesting

Cropping is the removal of fish of market size, i.e. 150 to 300 grams to decongest the pond and thus promote growth of the remaining fish.

To crop or harvest your fish, lower the net down to the bottom of the pond, sprinkle a small amount of feed on the water above the net, lift the net as fast as possible to prevent them from escaping.

7. Marketing

There is ready market for the fish. Join a market group like fish market for ease of marketing and selling your fish.

Introducing fingerlings in the fish pond

8. Restocking the Pond

After harvesting all the fish from the pond, leave it for about two weeks before restocking. If it is not raining, this period will allow the pond floor to dry so that nearly all the organisms die. Before restocking, remove silt and other materials from the bottom of the pond. The process as described for a new pond. If it is raining, add lime to the pond and then wait for two weeks before adding fertilizers or manure and restock 1 to 2 weeks later.

Fish farming is a very profitable enterprise if done with good management. Farmers should develop passion towards this less exploited agricultural opportunity.