Kisumu: The Kenya Marine and Fisheries Research Institute (KMFRI) has developed a new suitability map designed to optimize cage fish farming in Lake Victoria, aiming to avert the significant fish kills that have plagued the region, affecting farmers in Kisumu and Busia counties.
According to Kenya News Agency, the initiative follows recent events where massive fish kills due to upwelling in Lake Victoria resulted in substantial financial losses for local fish farmers. Dr. Christopher Aura, KMFRI’s Fresh Water Systems Research Director, highlighted that the new map pinpoints ideal locations for cage fish farming, prioritizing maximum production and minimizing risks. “Research has informed mapping by considering factors such as water quality, depth, security, and proximity to landing sites,” Dr. Aura explained. The map also takes into account fish breeding grounds and lake currents, which contribute to upwelling, a natural phenomenon where colder, deep water rises to the surface, depleting oxygen and harming f
ish.
Dr. Aura noted that the phenomenon of upwelling has been a known issue since 1990, occurring primarily during May, June, September, and October. He pointed out that the confined nature of cage farming exacerbates the impact of oxygen shortages on fish, as they cannot escape to areas with higher oxygen levels. To mitigate this, the suitability map advises against placing cages in shallow waters, where upwelling has a more pronounced negative effect, and suggests a depth of 6-10 meters as optimal yet still vulnerable.
During his speech at the Lake Victoria Aquaculture Forum in Kisumu, Dr. Aura urged farmers to collaborate and install cages in the identified deep-water locations, which, despite requiring more resources for construction, security, and surveillance, offer the most favorable conditions for fish farming. He also stressed the importance of investing in oxygen meters to monitor water conditions and advocated for the establishment of cold storage facilities to preserve fish stocks in emergencies
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Dr. Aura’s final advice to farmers was to regularly assess water quality and make informed decisions to prevent losses, underscoring the critical nature of these measures in maintaining a sustainable and profitable aquaculture industry in Lake Victoria.