This is six per cent of the total national export and three per cent contribution to the Gross Domestic Product (GDP).

Bigger picture

The statistics further indicate that despite the decline in fish export volumes from 39,000 metric tonnes in 2005 to 17,600 metric tonnes in 2014, export earnings increased from $104m (Shs 375.4b) to $135m about (Shs487.3b) as a result of the favourable international market price.

On the principles of management of capture and culture fisheries, Odonkonyero noted that they differ from each other.

In the case of capture fisheries, one has to attempt to harvest maximum sustainable yield by regulating fishing and by taking into account parameters of population dynamics like natural fishing mortalities and fish growth rate.

For the case of floating fish cages, things to consider in setting the cages including doing it at water shores and these way predators can be controlled easily.

It is easier raising Nile Perch in the cages because one may not feed them since they have large bodies, their cages allow smaller fish from the surrounding environment to freely swim in and out providing ready food supply for the captive Nile Perch.

A farmer has to fit the cages with lights to attract the smaller fishes.

"This research was done on Lake Victoria involving more than 2,000 cages owned by individual fish farmers. What is important to note is that the cages are raised therefore allowing fish that come to lay eggs at the shores to swim freely," he explained.

Floating fish cage farming helps in improving the situation of depleting fish stock during capture fish farming.

This is because farmers purchase the fingerlings, which are kept in the cages to grow.

Dr Anthony Taabu Munyaho, the director NaFRRI, explains that there is an enabling environment to increase production through cage fish farming.

Opportunities

There is already an initiative by the Zonal Research and Development Institutes (Zardis) to interest farmers in breeding fish through cage culture farming.

The cages to be made from metal pipes, which are placed together and held afloat using empty jerricans.

The walls of the submerged fish ponds are made from nets which are tied to the metal bars.

When the cages are assembled together they are fastened to the beach so that they cannot be swept away by the waves on the lake.
A farmer can decide to breed both sexes in the same cage or separate them.

In the study, it is illustrated that cage fish farming is the best option for a fish farmer who is already in the business or someone interested in fish farming.

A look at the figures show this. On average 419,249 metric tonnes of fish—mainly Tilapia and Nile Perch—is caught by 116,225 fishermen annually using capture system.

This suggests that on average each fish farmer produces four metric tons. Yet, if this is converted the other way, an individual farmer using cage fish farming would produce 48 metric tonnes annually.

There are 28 registered cage culture fish farmers in the country with a total of 2,135 cages operational around Lake Victoria. The limited number is because it is a relatively new technology, which can be traced to 2007.

The fish production from these cages is about 899 tonnes every six to eight months production cycle.

Most of them are concentrated in the central region—in Buikwe, Mukono, Rakai and Wakiso districts—and about 704 cages located in Jinja.

To note
Materials such as nylon, plastic, polyethylene and steel mesh which although more expensive have a longer lifespan and permit better water exchange, have superceded wood and bamboo. Most designs are of the floating type, and rely on a buoyant collar constructed either from locally available materials (for example, wood, bamboo), or from steel or plastic pipe, and from which is suspended a synthetic fibre net. Styrofoam or oil drums are frequently used for supplementary flotation.

Cages are floated in rafts, and either anchored to the lake/reservoir/river bottom, or alternatively connected to shore by a wooden walkway

Expert’s notes
It is more productive because, in most cases, the fish are fed.
You have to know the wind direction to align the cages well.
You also need to consider the nutrient content, rate of water flow and depth of the waters.