KENYA – A revised report from October 2022, conducted by four researchers, has raised concerns about the safety of fish harvested from Lake Nakuru in Kenya.
The study, led by Mary Florence Nantongo, Joseph Edebe, Elick Otachi, and Julius Kipkemboi, found that the fish from the lake still contains dangerous chemicals, rendering it unfit for human consumption.
The research involved collecting nine composite water and nine sediment samples, as well as 30 fish specimens, from five representative sampling sites within Lake Nakuru.
The findings confirmed the presence of selected organochlorine pesticide (OCP) residues in water, sediments, and Nile tilapia, posing potential health risks to those consuming the fish.
Despite the documented report warning of the dangers, the prohibited fish species continue to flood several fish markets within the country.
This rampant sale of contaminated fish is putting consumers’ lives at risk. Grace Nyambura, Chairperson of the Lake Naivasha Patrol Network, admitted in an exclusive interview with the Nation that the sale of these fish is still ongoing, urging enforcing agencies to crack down on the illegal business.
The study’s findings have not only raised health concerns but have also impacted fish operators in Naivasha.
Ms. Nyambura, also the Lake Naivasha and Oloiden Fishers Community Based Organization Chairperson, called for concerted efforts to address the issue, emphasizing that the researchers’ concerns serve as a “wake-up call” for the relevant authorities.
In response to the alarming findings, the researchers recommended that policymakers implement an environmental monitoring program and mitigation measures to reduce pollutant inputs into Lake Nakuru.
They emphasized the need for a ban on the harvesting and consumption of fish from the lake to safeguard public health.
Ken Barasa, Nakuru County Chief Officer for Environment, acknowledged the difficulty of arresting toxins flowing into the lake due to its natural resource position.
The lake’s ecosystem faces contamination from industrial waste and metals washed away from uncontrolled garages, making it challenging to address the issue effectively.
The presence of most organochlorine pesticides in the environment, though banned in Kenya, poses potential long-term health hazards to humans.
The report calls for immediate action to protect consumers and the delicate ecosystem of Lake Nakuru.
KEMFRI’s 2021 Research
The Kenya Marine and Fisheries Research Institute (KEMFRI) had earlier in 2021 conducted a research that showed that the fish animals in the lake contained dangerous chemicals. This led to a ban on all fishing activities in the lake.
The research identified alarming levels of toxic substances in the lake’s fish, warranting immediate attention.
Notably, the levels of Chromium detected exceeded the Food and Agriculture Organization’s (FAO) permissible limit of 0.14mg/l. Furthermore, toxic heavy metals were detected across all fish samples.
The presence of these substances in small concentrations may not pose an immediate health threat to consumers of fish from Lake Nakuru. However, the researchers cautioned against prolonged consumption, as the heavy metals have the potential to accumulate in the body, leading to adverse effects.
The researchers identified pollution as a significant contributor to Lake Nakuru’s distressing condition.
A startling 65 percent of untreated human waste finds its way into the lake due to inefficient transport and treatment systems. Additionally, inadequate management of solid waste, stormwater, and drainage has exacerbated the pollution crisis.
As a consequence of these factors, Lake Nakuru has become completely anoxic—a condition where oxygen levels are severely depleted—and unsupportive of life, particularly in its mid-lake region and depths below one meter from the surface.
Heavy metal menace
The 2021 study also unearthed presence of various heavy metals in the lake such as arsenic, cadmium, chromium, lead, nickel, mercury, selenium, cobalt, copper, and zinc. Worrisomely, Molybdenum metal was also found in excessive amounts.
The accumulation of chromium, copper, lead, and zinc in sediments is attributed to unregulated discharges and the lake’s unique characteristics. Lake Nakuru’s alkaline nature and lack of an outlet contribute to the concentration of heavy metals in its sediments.
The ban on fishing activities was just a first step; a comprehensive strategy that addresses pollution sources, water management, and waste treatment is urgently required. Safeguarding the lake’s ecosystem, as well as the health of those who rely on it, demands collaborative efforts to restore this vital natural resource.