By Martin Wakaba – an aspiring entrepreneur who has several startup projects
Fish farming in Kenya got a huge boost in 2015 when the EU opened up its market to Kenyan commercial farmers. Before then, only fish and fish products from natural sources in Kenya were allowed into the EU region. With fish stocks in most regions falling due to the adverse effects of global warming and environmental pollution, the fish farming adventure can only get more lucrative and rewarding. This is because the supply of fish and its products has hugely decreased even as the demand for the same continues to grow. Besides, the changing eating habits have hugely benefitted the aspect of fish rearing given that studies have found out that fish have high levels of proteins that are essential for dietary functions. Locally, the situation could potentially help farmers who rear fish in ponds. As the prime form of aquaculture, fish farming entails raising fish for commercial purposes, typically for food. As a potential source of income, what does one need to start the fish farming venture? For beginners, fish farming can translate into a poverty eradication approach for local communities through job creation, provision of vital dietary proteins and as a source of income.
First, one needs a piece of land to set up the ponds – it doesn’t have to be a big chunk of land. Ideally, fish farming can be practiced even in areas where land is limited given that the venture requires small pieces of land. Clay is the best type of soil to rear fish given that it doesn’t allow huge volumes of water to sips through. As an inexpensive venture, open fish ponds are more ideal for starters. A pond is dug on a relatively level ground and then a polythene layer is fitted in the pond. Digging the pond should be done in appropriate measurements – the upper part of the fish pond should be 0.5 m deep while the lower side should be 1.5 m deep. A dyke is then built and filled with clay and compacted so as to prevent seepage. An inlet, outlet and spillway are then dug on the pond in order to allow the water to flow freely. The aim of the polythene layer is to aid in retaining the water. Hilly places may not be as advisable in that they may attract more costs by breaking the walls to level grounds. Then, some little soil is placed strategically in the bed with some plankton seeds. After this is achieved, water is poured to the pond.
Basically, a farmer has to choose between two types of fish – fresh warm water fish and fresh cold water fish. Fresh warm water fish are reared in waters that have a temperature of 18° Celsius or more. They include tilapia, cat fish, black bass, striped bass, carps, bluegill as well as Nile perch. Fresh cold water fish such as trout are found in waters that have temperatures between 10° and 15° Celsius. Of notice is that one requirement of rearing fresh cold water fish is that the water has to be flowing always. That means these types of fish are not ideal for the local farmers who prefer the low cost model of fish ponds. The farmer should get advice from the relevant agencies about the right type of fish to rear because different fish species do well in different geographical areas. The fingerlings can be obtained from hatcheries such as Bamburi Nature Trail, Sagana, Kisumu ﬁsheries, Kiganjo etc. The fingerlings are transported to the ponds in oxygenated polythene bags that have a temperature of around 10° Celsius. The farmers should take maximum care to avoid harming the fingerlings. The fingerings are lowering to the pond by tilting the polythene bags to allow them to swim away. Overstocking could bring about a decrease in yields, and hence an average of five to ten fingerlings per 5m2 area of fish pond is desirable.
After acquiring the fingerlings, the farmer should make sure that water is flowing freely in the pond to make sure that enough oxygen is supplied. For the small-scale farmers who have constrained budgets, fingerlings can be fed cheap foods such as kitchen waste, slaughter house waste, chicken manure, leaves, groundnut cake and leaves. The food should just be enough for the fingerlings as excess food can cause pollution of the pond resulting to the rotting of the fingerlings. Planktons are also a good source of food for fish, and it should be planted into the pond. Manure should be added to the pond to encourage the growth of planktons. Once mature, fish can be harvested for sale or consumption. Cropping is the harvesting of fish that have attained the marketable size. The most effective harvesting method for upcoming fish farmers is the usage of seine nets. When harvesting fish, nets measuring 3.0— 3.5 cm are used and this approach is highly effective in that only marketable fish are caught. That means the smaller fish swim back to the pond awaiting their appropriate harvesting time and they are not injured in the process.