Sun. Dec 10th, 2023
Despite the risks, fish farms are thriving in Africa

“It was horrific,” Alan Ochieng says of the catastrophe that struck Lake Victoria fish farmers late final yr.

Hundreds of fish died when Africa’s largest lake witnessed a pure and recurring phenomenon often called backside water rising to the floor.

This happens when deep water mixes with floor water, inflicting a sudden depletion of dissolved oxygen within the water, killing fish.

Some farmers imagine excessive algae ranges or air pollution could have performed a task.

Mr Ochieng misplaced all of his 120,000 tilapia, virtually half of which have been prepared for harvest. Many different farmers suffered comparable losses.

The businessman, with three companions, owns 24 cages, close to Ugal Seashore on the Kenyan coast, which value them round $100,000 (£80,000). They spent one other $185,000 on child tilapia, feed and delivery.

“Cage farming carries large dangers, nevertheless it may also be very worthwhile,” says Mr Ochieng, who is decided to proceed.

Because the title suggests, cage aquaculture includes elevating fish in a mesh cage. It has turn out to be one of many quickest rising meals sectors in sub-Saharan Africa, as wild fish shares have declined and demand for fish has risen.

The variety of cages elevated from 9 in 2006 to greater than 20,000 in 2019, in keeping with a latest report. Study published in Nature Food.

In East Africa, between 2017 and 2021, the dimensions of the trade tripled, in keeping with Gatsby Africa Report.

Tilapia fish at Al-Nasr Farms

In Africa, the demand for fish resembling tilapia is rising

Yalelo Zambia is the biggest tilapia producer in sub-Saharan Africa, producing a mixed 25,000 tonnes of the fish at its amenities positioned on Lake Kariba in Zambia and on the Ugandan facet of Lake Victoria.

It’s an more and more high-tech firm, says the corporate’s CEO, Ulrike Daniel.

The chief govt advised the BBC: “Whereas we’re coping with a product we can not see, as soon as it’s underwater we now have to rely closely on expertise to measure what is definitely occurring under the floor.” He provides that cage farming is extra data-rich than the poultry trade, for instance.

He says all this information may assist mitigate agricultural disasters like final yr’s.

“Backside water upwelling can occur all of a sudden, however some indicators can predict its prevalence,” says Daniel. “So, day by day we measure dissolved oxygen, pH values ​​and ammonia content material within the water.”

“As soon as we see the primary indicators of rising backside water, we will scale back the variety of fish within the cage to stop mortality.”

Victory Farms, the biggest producer of caged fish in Kenya, additionally collects a number of information.

“We measure a number of depths and places to evaluate underwater exercise and biology, assess algae within the lake as an indicator of backside water rise, and if dissolved oxygen ranges are low, we study water currents in addition to the extent of algal buildup on the floor of the water,” says CEO Joseph Rahman. .

“With a seven-year historical past of information, we will now sometimes predict whether or not there’s a excessive, medium or low danger of backside upwelling. If there’s a excessive danger, we modify stocking densities, scale back feeding, and gradual or cease fish dealing with. “Each to scale back stress.”

Harvesting fish at Al-Nasr Farms

Giant-scale farmers can afford the mandatory tools and expertise

Victory Farms has additionally developed expertise to scale back losses whereas transporting dwell eggs to the hatchery.

They’ve developed a cell incubation system, which retains the eggs shifting in oxygenated water.

The expertise arose from a venture to construct hatchery ponds on plots of land within the neighboring group.

In return, individuals are paid for the harvested fish eggs, that are then transported to Al-Nasr Farms’ ponds.

Such improvements are past the attain of the rising variety of smallholder farmers who’ve ventured into cage farming.

Small scale fish farm in Kenya

Small fish farms have gotten a well-liked rising enterprise enterprise

“Though it is very important measure oxygen ranges in cages, most smallholders don’t do it as a result of they can not afford the required tools, which prices greater than $1,000,” says Dave Okesh, president of the Kenya Cage Fish Farmers Affiliation.

One other downside, in keeping with Mr. Okesh, is the lack of understanding amongst many new farmers. “In consequence, some place their cages in water that’s too shallow, which may result in water air pollution, and may result in a excessive mortality charge if backside water rises to the floor.

“Some entrepreneurs additionally use low-quality feed that sinks, which negatively impacts the ecosystem and causes losses, as tilapia feed on floating pellets,” Mr. Okesh provides.

He believes extra exact feeding will result in more healthy fish and save farmers cash.

His firm AquaRech is at the moment engaged on a system to observe water temperature in cages.

That is an important piece of information, he says, as a result of chilly temperatures make it troublesome for tilapia to digest what they eat.

Armed with this info, his system can advise farmers on precisely how a lot feed to make use of.

“We want this type of innovation to professionalize the sector and make it extra productive and helpful for its individuals,” the Kenyan businessman provides.

More business technology:

Nevertheless, some are involved in regards to the trade’s speedy progress. There may be concern in regards to the great amount of uneaten feed and fish feces that accumulate underneath cages, and its affect on water high quality.

“The presence of those environmental points underscores the significance of inserting fish cages responsibly, in deep sufficient water with adequate water circulation,” says Chrisven Nyamuya, a analysis scientist on the Kenya Marine and Fisheries Analysis Institute.

Joe Rehman of Victory Farms says his firm and authorities officers frequently take a look at water circumstances.

“To this point, we have not had any issues with the capability to carry fish,” he says.

He factors out that overfishing has led to the depletion of untamed fish in Lake Victoria.

“If Victory Farms right this moment has 3,000 tons of biomass, we’re including to the nutrient load, however inside the pure carrying capability that existed earlier than human-driven overfishing depleted the lake.”

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