A research scientist in the Aquaculture industry has downplayed the current fish deaths being witnessed in Lake Victoria which borders Kenya Uganda and Tanzania, saying it is a periodical normal occurrence.
Speaking at Kegati Aquaculture Research Centre in Kiogoro Sub location, Kisii County during a ponds inspection exercise Wednesday, Assistant Director Fresh Water Aquaculture Dr. Paul Orina said the same experience was noted about five years ago, only that it lasted one week while the current has taken close to three weeks leaving a greater impact.
Aquaculture research centre is under the Kenya Marine and Fisheries Research institute (KEMFRI).
Dr. Orina attributed the deaths to disturbance of the structure and conditions of the lake through mixing of the top, middle and the bottom layers of water mainly due to winds, floods, inflow and outflow of water.
These, he said, affects the levels of oxygen and chemicals thus affecting the fish which have different adherence to different levels of oxygen.
He explained that Nile Perch (locally known as Mbuta) of all sizes were the most affected in the temporal lake occurrence owing to their high oxygen demand as is currently being witnessed in the counties along the lake with Siaya reporting the highest number of deaths.
He also cited Burbus (Odhadho) and Labeo (Ningu) as species with high oxygen demand, but said their deaths were lower because their numbers were few due to declining fisheries in the lake.
He termed Tilapia (Ngege), Catfish (Mumi) and lungfish (Kamongo) as resilient species which are not easily affected by the lake’s seasonal occurrence which could also be due to climate change.
However, Dr, Orina noted that one way of ensuring that oxygen levels of the lake did not vary with a big margin at different density levels was by maintaining a clean ecosystem adding it was key in ensuring the over five million people that depend on the lake continued to access clean water as per the Sustainable Development Goals (Global Goals).
“This calls for fast implementation of the water quality regulation whose objective is to prohibit discharge of effluent into the environment in a bid to preserve the aquaculture industry and wild fisheries which are critical in ensuring food security in the Country,” said Dr. Orina.
Emphasizing the need for stakeholders to implement the regulation with the same zeal they did on the plastics ban, Dr. Orina said it had reduced depletion of the environment including the water bodies referred to as the blue economy.
Dr. Orina also called for sensitization on benefits of adhering to the Water Quality Regulation which is under the Environment and Co-ordination Act (EMCA), 1999 including education on separation of waste through introduction of different bins properly labeled to dispose different kinds of waste.
Terming pollution a global menace, Dr. Orina said good agricultural practices and control of industrial waste will also prevent toxins, nutrients and radioactive matter from finding its way into water bodies through runoff and floods while eradication of water hyacinth will also increase air circulation.
He said the current situation at the lake should not be a cause for alarm as it would wane in the near future and the numbers of fish affected on the Kenyan side and neighboring countries was negligible compared to the total fish population in the lake.
by Jane Naitore/Clinton Nyamumbo