Feature of the Week

Fish harvester passes trial

As fish catches in Lake Malawi and other natural water bodies keep falling, Malawians are switching to fish ponds for animal protein.

Despite the increasing number of fish farmers, every person in the country consumes an average of eight kilogrammes of fish per year. The fish uptake constitutes two thirds of the expected uptake of 12 kilogrammes stipulated in the National Fisheries Policy.

This could be one of the reasons a fifth of the citizenry suffer malnutrition.

This persists at a time many farmers lack efficient harvesting props, exposing the fish to predators, thieves and stunting.    

Farmers marvel at the new fish trap developed by researchers in Domasi

“It is challenging that while we are promoting fish farming, farmers lose sizeable fish stocks due to failure to partially or fully harvest fish for their household consumption. Some lack even harvesting nets and other simple technologies,” says Geoffrey Kanyerere, deputy director of research in the Department of Fisheries.

This, the expert says, reduces farmers’ profits and nutrition security while thieves and predators prey on the fish.

A series of trials are underway at the National Aquaculture Centre in Zomba to improve fish harvesting technologies.

The department is testing the new technologies under a project funded by GIZ which seeks to enhance the aquaculture value chain for higher incomes and food security.

The researchers envisage the intermittent harvesting fish trap help farmers catch part of their stocks in the course of production.

This follows year-long experiments to determine the effectiveness of the fish trap, which is made of chicken wire mesh, on red-breasted chambo (Tilapia rendalli) and makumba (Oreochromis shiranus).

The common species in the country’s ponds were subjected to trials at the fisheries centre in Domasi and in the ponds of 23 pre-selected fish farmers in Zomba.   

According to co-researcher Buga Siyangwe, the circular-shaped fish trap is made of wire mesh with 0.7 centimeters openings. It measures 120 centimetres long with adjustable openings of five centimetres on both ends as fish entrances.

“The entrance can be adjusted depending on the targeted size of fish to harvest,” Sinyangwe explained.      

During the experiment, his team dangled maize bran and formulated floating pellets to lure the fish into the trap.

“The technology caught an average of six kilogrammes of fish per hour. However, the floating pellets capture more fish than madea due to its high palatability,” Sinyangwe explains.

The technology worked well during the day, the preliminary findings show.

The researchers urge farmers to set the traps during the period they usually feed their fish.        

Experts and fish farmers say the modified technology is user-friendly and does not involve a lot of work.

This makes it easy to use, especially for the youth and women.

The trap does not capture small fish as one can easily select the size of the targeted fish by adjusting the mouth ends.

The technology is also used to sample fingerlings and select the mature fish used for breeding purposes.

Kanyerere and Siyangwe say the harvester offers farmers the ease to achieve nutrition security and selectively catch their fish for household consumption and selling.

“A fish farmer’s household no longer has to starve while waiting for final harvesting,” says Kanyerere.

Snap surveys conducted during the experiments confirmed that both urban and rural markets consume small-sized fish species, making the fish trap relevant. 

Frazer Kumwenda, a member of Innovative Fish Farmers Network, asked the Fisheries Department to swiftly roll out the technology to all fish farmers.

However, he expressed concern that the affordable fish trap may encourage fish theft from ponds like his.

Deputy director for fisheries extension Jaqueline Kazembe hailed the researchers and fish farmers for jointly coming up with the innovation likely to increase fish consumption for a healthy nation.

She pledged continued collaboration in different fields to tackle both existing and emerging challenges affecting the fisheries sector.

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