Will cage farming raise fish stocks?

By Vision Reporter

Added 28th January 2020 02:31 PM

According to Aga Ssekalala, lake cage fish farming is the way to go if the dwindling fish in Lake Victoria is to be saved.

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According to Aga Ssekalala, lake cage fish farming is the way to go if the dwindling fish in Lake Victoria is to be saved.

PHOTO: Some of the fish cages set up in Jinja

From a distance, the structures look like a bridge cutting across a section of the lake, in Namusenyi village, Buikwe district.

As you move closer, you realise that these are more than bridges, but rather a cage fish farm.

This one is owned by businessman and farmer Agha Ssekalala Sr. The setup has over 250 cages filled with fish.

This is one of the few large water body cage fish farming projects in Uganda. The other one owned by Prophet Samuel Kakande will soon be set up in Bukakata, after it was authorised by the government.

According to Aga Ssekalala, lake cage fish farming is the way to go if the dwindling fish in Lake Victoria is to be saved. His establishment is quite big, but not entirely new in Buikwe and Jinja areas.

Early research/pilot project
Cage farming is an old system across the world. In the Far East, the system has been used for years. In Africa, it was first piloted in West Africa and then on Lake Kariba in Zambia in the 1980s.

In Uganda, viability studies were started in the 90s at the National Fisheries Research Institute, Jinja. The Government, under the Uganda – China Friendship Agriculture Technology Centre introduced a sh12.8b three-year pilot cage fish farming project.

The system emphasizes proper management of fish in natural waters stocked in mesh size nets. Over 50 pilot rack cages were fixed in Lake Victoria.

A team of Chinese experts helped teach NaFIRRI experts how to manage cages, growing fish fry and manufacturing feed. Between 400 to 500 young fish per cubic metre are stocked in a 25 square metre mesh cage. The results are amazing as the cages have produced fish faster than the open lake can do.

Barry Kamira, a cage culture research scientist at NaFIRRI, says at least three tonnes of mature fish are harvested every three months.

“The yields are higher and more controlled,” Kamira said in a media interview.


Liu Guanghu, the head of the cage culture pilot project said the fish harvest has been boosted by a minimum of 12 tonnes of fish every year from 50 rack cages in Jinja alone compared to 300,000 tonnes caught from the 31,000 of Lake Victoria in 2011. It is because of this successful piloting that private investors like Ssekalala and Kakande have taken up cage farming.

How it works
Fish cages are placed in lakes, ponds, rivers or oceans to contain and protect fish until they can be harvested. The method is also called “off-shore cultivation” when the cages are placed in the lake.

Fish are stocked in cages, artificially fed and harvested when they reach market size. The cages vary in size. Each of the boxes is about 3x3 metres in size. The boxes are interlinked by pipes and a wooden bridge on which caretakers access them during harvesting and feeding. The interlinked structure can be as long as 100 metres.

Ssekalala says that before one makes a selection of a spot for the cages, serious studies must be undertaken to determine the depth of the lake at that particular area, the direction of heavy winds that may cause waves in the area, etc.

In terms of materials, the cage requires a metallic mesh, that is constructed into a box and placed in a section of the lake. The structure is fixed with floaters so that it does not sink. In the case of Ssekalala, he uses plastic drums. The cage is then covered by another mesh that is, however, opened during feeding and harvesting. The other advantage-compared to traditional pond fish farming is that there is no need for water quality control, since this water is recycled within the lake.

According to Ssekalala, the fish in cages is also very easy to feed. Ssekalala feeds his fish on pellets.

“We use floating pellets (bagiya) to feed the fish. The advantage is that the feeding is well controlled so there is no wastage,” he says.

Because of the easy and targeted feeding, the fish grow faster. “The system is good for replenishing fish stocks in the lake and at the same time increasing stocks harvested from the lake,” Ssekalala said.

In one harvest, Ssekalala got 3.5tons of fish, all of them tilapia, from an area less than 100 square metres. Ssekalala says that you can have a good harvest every after 6-7 months after stocking.

“Your production is predictable, which is not so with fishing in the wild. You may go out with 100 nets and you come back with two pieces of fish. But if you have your cage and you have looked after these fish very well, you can predict the production, and even the money that you can get from it,” he said.

Minister Nankabirwa responds
Cage farming on Uganda’s lakes has now got full approval from the Government.

The state minister for fisheries, Ruth Nankabirwa, says cage fish farming can help Uganda to increase fish stocks in its lakes.

“When the public embraces cage fish farming Uganda will be in a position to produce enough fish for both local consumption and export,” she says.

Dr. Stephen Kiwemba, the Jinja district production officer, says rack cage fish farming has a huge potential provided the farmers are guaranteed security.

“Having seen the harvests from the cages, I think it is a good system of keeping stocks of fish high in the lake,” he says.

Environmental concerns

Despite the advantages associated with cage fish farming, some Ugandans are not happy with the plan. They say it will give more power to very few individuals to own the lake, depriving other lake users of their rights.

Perhaps the biggest challenge is the cost of setting up the structures, which may not be affordable by smaller fishermen.

“Not every fisherman will afford this practice. This means that many of them will be deprived of a right as those who have money scramble for the lake,” lamented Samuel Musisi, a fisherman at Bukakata landing site.

 “The lake is a public good, so when they start demarcating it and making some portions of it no-go areas for some fishermen, then this is a case of deprivation of their rights,” says Frank Muramuzi, the executive director of the National Association of Professional Environmentalists (NAPE).

However, according to fisheries minister Ruth Nankabirwa, cages will not be set up in places where they can deprive other lake users of access to the lake.
Indeed, when you look at Ssekalala’s establishment for example, it occupies a very small section of the water and does not stop other lake users from accessing the lake.

The cages are not allowed to block any approach to a public landing site.Environmentalists believe that caging lakes may contaminate the water bodies with chemicals from fertilizers, the farmer will be using in the fish cages.

Muramuzi says, the investors might introduce alien fish species that may eat up other fish in the lake.

According to the National Environment Management Authority (NEMA), it is a pre-requisite to carry out an environmental impact assessment. NEMA boss Dr. Tom Okurut said they have carried out assessments on all the cages so far set up on the lake.

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