Electronic fishing rigs increase harvest 10 fold

Fishing rigFish farmers in Uganda are poised to grow their catches ten times with modern fishing rigs that are set to replace the traditional kerosene powered lamps as demand for the silver cyprinid fish locally known as Mukene soars due to its superior nutritional value.

According to a researcher from National Fisheries Resources Institute (NAFIRRI) Dr. Taabu Anthony, overfishing, overpopulation and increased export activities have contributed to the decline of both Nile perch and Tilapia depriving most families of the most popular fish species on their menu. As a result, some families opt for Mukene which unsurprisingly has been on the increase. “There have been an increase of both Silver cyprinid (Mukene) and Dagaa (Enkejje) in Lake Victoria and the decrease of tilapia and Nile perch, which in the 1990s, had increased to 10 per cent per micro mile,” Dr. Taabu further noted that despite the windfall of Mukene biomass in Lake Victoria supply is low and cannot sustain the current demand. This is mainly due to poor and archaic fishing technologies accessible to the farmers.

Traditionally fishermen have relied on kerosene powered pressure lamps during harvesting with the light from the lamp being used to attract and concentrate Mukene. But this method has had a toll on fish yields as light from a single lamp can only concentrate a few Mukenes. The lamps also emit hundreds of thousands of tons of carbon emissions annually into the air and the fishermans' lungs.

To save the situation, a Zimbabwean firm, Arrow Aquaculture Africa (AAA) having successfully utilized industrial fishing rigs on Lake Kariba in Zimbabwe to harvest Mukene transferred the technology to Ugandans for trials. The firm introduced the industrial rigs at Kiyindi landing site in Buikwe district.

The fishing rigs use light from electric bulbs supplied by a generator to attract and concentrate fish. While using this modern technology, the catches range from 280 – 4500 kg per rig per day according to season compared to 40 – 70 kg harvested by fishers using pressure lamps.

Its’ perceived that light intensity during Mukene harvest determines the quantity of the catch., Dr. Taabu noted that preliminary results from studies he carried out indicated a correlation between the light intensity and Mukene catch. “Fishers using 1-7 pressure lamps per group get their catch based on the intensity of their lamps signifying the importance of a reliable source of light for harvesting.”

The researcher has praised the trials of using the industrial rigs noting that it is very productive in comparison to the pressure lamps. Although the initial rigs being used in the trials at the lake ten times more expensive than the ordinary kerosene lamp units, Dr. Taabu explained that there is work in progress to offer similar innovative solutions that are affordable. The success of the rigs makes it essential for us to develop cost-effective technologies that will enable increased but sustainable exploitation of Mukene.

“Our aim is to increase sustainable fisheries production of Mukene by improving light attraction technologies through the determination of the most appropriate colour, intensity, and source of light for attraction and concentration of these small fishes. The enhancement in the use of the improved technologies to attract and concentrate these fishes will increase production to at least 50 – 60 percent, relieve pressure on other large fish stocks, and improve local revenues and the nutritional status of the poor Mukene fishing population,” said Dr. Taabu

Mukene contains phosphorous which aids brain and bone development. It has also got nutritional values such as vitamin A and E and fatty oils that prevent poor vision and promote good skin texture. Studies have shown that diets rich in Omega-3 can result in increased learning ability, problem-solving skills, focus, memory and creativity.

Statistics from the Department of Fisheries Resources show that fish exports in Uganda increased from 1,664 tonnes worth $1.4 million (about Shs3.5 billion) in 1990 to 36,615 tonnes worth $143.6 million (about Shs362.6 billion)in 2005, but dropped sharply back to 16,480 tonnes fetching $89.1m (about Shs225b) by 2011.