How technology brought tilapia to chilly Nyandarua
For many years, prospective fish farmers in Nyandarua County have been grappling with breeding warm-water fish species faster in the cold region on the edge of the Great Rift Valley.
On average, such warm-water fish require temperatures of between 20 and 25 degrees Celsius to breed and grow faster to earn farmers profits.
But Nyahururu’s temperatures average 13 degrees Celsius and can hit lows of 10 degree Celsius.
The introduction of greenhouse fish farming technology by a non-governmental organisation, Tree is Life, is expected to help change the fortunes of farmers in the twin counties of Nyandarua and Laikipia.
“In a greenhouse, tilapia fingerlings can attain a weight of up to 100 grammes within three months, which is impossible under natural conditions. They feed and breed better under these controlled conditions,” says Mr David Ruhiu, one of the first farmers to try out this technology.
On his 1.5-acre farm that overlooks Lake Olborosat — a few miles from Nyahururu Town on the Nyeri-Nyahururu road — the father of four runs five fishponds, teeming with tilapia and catfish. However, inside a greenhouse next to these ponds, is another 30 by 10 metre pond he says is not only the lifeline of the other five, but also of the families in the area.
It is from this pond that he breeds his fish and raises the much-sought after table-size fish.
But why cover up an entire fishpond with a greenhouse?
“We realised that weather variability has impacted negatively on fish farming in the county. Our research showed that changed water temperature through the greenhouse can boost fish production, especially in cold counties such as Nyandarua,” says Mr Thomas Gichuru, the director of Tree is Life project.
Under the fish project funded by ACT, a national donor organisation, the county fishing department picked four farmers to start greenhouses on their farms for the piloting phase. All were chosen for their wide knowledge and experience in fish farming.
“Each had to prove that he has access to ample water supply throughout the year, dig a fish pond to the required specifications, stock it with fingerlings, and then demonstrate keen interest and initiative so that the project input would bear fruit in the long run,” says the director.
The organisation supplied selected farmers with all greenhouse building materials and dam liners that reduce seepage of the water, valued at a cost of Ksh330,000.
One of the farmers who qualified for the project, Mr David Ruhiu, dug a fishpond at a cost of Ksh18,000 and invested a further Ksh100,000 to stock it with fingerlings. He sank two wells to guarantee uninterrupted water supply to the fish ponds, especially during the dry season.
The greying clay soils on his farm made it ideal for pond construction. They are well compacted, allowing very little seepage of water for years.
The greenhouse changed the farmer’s fortunes within seven days. It has not only increased the growth of his fish stock, but also eliminated a cumbersome process of breeding.
Previously, Mr Ruhiu would mix male and female fish in the breeding ponds to mate and lay eggs. He would then squeeze the eggs out of the female mouths and carry the fertilized eggs to his house, where he incubated them under room temperature before returning the fingerlings to the main ponds.
“A lot of eggs and fingerlings would be lost in the process,” he says.
The green house fish technology has changed all that. Today, the fish hatch and incubate in cages inside the greenhouse pond. The fingerlings are raised in cages suspended in the main pond where they are fed separately from other fish although they share the water. They are also protected from bigger fish.
He is also closing the supply demand gap for fingerings, thanks to doubled hatching and the incubating rate.
Within a month, he supplied 50,000 fingerlings to other farmers and organisations at Ksh20 each, earning Sh1 million.
“With the growth of fish farming and consumption, the demand for fingerlings and fish, in general, is so high that local farmers cannot meet it,” he says.
The greenhouse fish technology is the solution to the problem that he and other fellow fish farmers have been struggling with for years. He no longer has to worry every time temperatures drop.
“Sometimes, overheating can lead to temperatures soaring to 34-38Cº, making the water dangerously hot and lethal. It becomes appropriate to roll up one side of the greenhouse canvas to allow cool air into the pond,” he says.
Better still, he can now make apt projections and timelines in his fish production calendar.
“It’s easy estimate the number of fish attaining maturity and calculate likely earnings.
It is also possible to breed and raise fish irrespective of climatic conditions,” says the project director.
The four pilot greenhouses will also be used to train more people on fish farming, promote value addition and become the source of fingerlings to future rollout of the project.
A few fish pond tips from Mr Ruhiu
- Feeding: A critical aspect of fish production is done using fish pellets that farmers can formulate on the farm to cut costs.
- Management: You can raise catfish and tilapia together without them having to cannibalise each other: “Introduce tilapia first and raise it for three months before stocking catfish. By the time the catfish have attained the size where they can start predating on the tilapia; most of the tilapia will have been harvested.”
20 kgs: Per capita fish consumption in the world annually
7 kgs: Kenya’s yearly per capita fish consumption
129,300: Number of Kenyans who derive their livelihood from fishing and fish farming
480 ha: Total area of Kenya under fish farming
23,500 tonnes: Annual production of Kenya’s fish farmers
(Source: Food and Agricultural Organisation (FAO)