44 illegal fishermen operating in Lake Nakuru have been nabbed following a crackdown mounted by a government multi-agency team appointed by President William Ruto, in an operation that saw the destruction of over 300 fishing gear.
Kenya Wildlife Service (KWS) Senior Assistant Director Joseph Dadacha who is also the multi-agency team’s chairperson further confirmed that 2,074 kilograms of fish had been intercepted, while two motor vehicles and two motorbikes, believed to have been used to facilitate the illicit trade in the protected area had been impounded.
Dadacha expressed concern that though the fish from the Lake had been declared by various research agencies as unfit for human consumption due to high traces of toxic contaminants from the sewage system, farms, settlements, and dumpsites on the water body’s catchment, unscrupulous fish mongers were sneaking them into markets within Nakuru town, Naivasha, Nairobi, Kericho, Bomet among other areas where unsuspecting members of the public buy and consume the fish.
He said illegal fishing at the water body had increased human-wildlife conflicts citing several reported cases of attacks on humans by hippos.
Dadacha noted that the practice was also a threat to endangered wildlife species adding that Lake Nakuru National Park and Bird Sanctuary was home to endangered black and white rhinos and rare bird species which could be vulnerable to poachers posing as fishermen.
The KWS Senior Assistant Director warned that Arsenic, Cadmium, Chromium, Lead, Nickel, Mercury, Selenium, Cobalt, Copper, and Zinc were reported as the most frequently occurring potentially hazardous heavy metals in Lake Nakuru water with Molybdenum metal reported as exceeding the recommended standards.
“Chromium (Cr), Copper (Cu), Lead (Pb), and Zinc have accumulated in the sediments as a result of unregulated discharges and because this alkaline lake has no outlet,” he noted.
The KWS Assistant Director who is also in charge of the Central Rift conservation area noted that although Lake Nakuru is not gazetted under fisheries laws for commercial fishing, illegal fishing started in 2020 following the swelling of the lake.
By March 2020 fishermen started migrating from Lake Naivasha with their fishing equipment, and by August 2020, over 50 fishing boats were illegally operating on Lake Nakuru.
The multi-agency team has members drawn from state agencies, including Kenya Fisheries Service, Kenya Marine and Fisheries Research Institute, Kenya Wildlife Service, National Environment Management Authority, and Water Resources Management Authority.
It is constituted at the national and county levels to develop a strategy to address issues related to the illegal fishing activities at the lake that pose a threat to human health and the wildlife and tourism industry.
Dadacha indicated that Lake Nakuru’s surface area increased from 35km² in 2013 by 100% to 71km² in 2020, a situation that led to a spillover into the neighboring villages.
He added that before its increased water volumes only salt-tolerant Magadi tilapia grahami which was introduced in 1953 existed within the soda lake and that increased water volumes over time have been linked to the increase in freshwater fish.
“The Increasing water volume attributed to heavy rainfall in the catchment contributed to the dilution of the once saline lake to a more habitable environment for freshwater fisheries. Fish is likely to have escaped from flooded fish ponds and dams in the catchment to acclimatize in the lake,” stated the conservation isn’t.
The fisherfolk at Lake Nakuru have devised ingenious ways of beating the ban with illegal fishing expeditions being carried out at dawn and night.
Mr Dadacha has now issued a stern warning against the practice.
“We have been conducting sensitization drives in areas neighbouring the lake including Baruti and Mwariki to discourage locals from engaging in illegal fishing or consuming the fish. We want to tame cases of human-wildlife conflict among other challenges that have been leading to loss of lives,” added Mr Dadacha.
The Lake Nakuru National Park is also home to lions, gazelles, baboons, zebras, leopards, and buffaloes among others.
County Chief Officer in charge of Livestock, Fisheries and Veterinary Services Dr. Michael Cheruiyot disclosed that water and fish samples independently collected fish from the lake by Egerton University, Kabete Food and Veterinary Laboratory, and Kenya Marine and Fisheries Research Institute (KEMFRI) had established the presence of heavy metals both in the lake’s water and fish.
Dr. Cheruiyot indicated that research by four scientists attached to KWS in December last year revealed that samples of fish collected from the lake had high levels of 16 different organochlorine pesticides (OCP).
The Chief Officer added that fish tissue samples from the lake also had high levels of nitrates and traces of other hazardous chemicals.
He warned the locals that fishing outside the game reserve and private farms where the lake waters have spilled over had also been outlawed.
Lake Nakuru, according to a recent study, currently has three newly introduced tilapia fish species that previously never existed.
According to a 2022 survey undertaken by KEMFRI, dominant fish species within the lake include Nile tilapia Oreochromis Variabilis, Alcolapia grahami, and Oreochromis leucostictus.
Besides Nitrate, Dr. Cheruiyot explained that the concentration of chlorophyll-a in the fish was found to be 84.49 milligrams/litre (mg-1) while others had a concentration of 77.35 mg-1.
“Some of the points within Lake Nakuru were found to have the nitrates at a concentration of 67 milligrams per litre indicative of organic and inorganic discharge into the lake, possibly originating from industrial or municipal waste. The concentration of chlorophyll-a, is indicative of the excessive nutrient loads in the water and led to an increase in algae biomass,” noted the Chief Officer.
He stated that nitrates are toxic in amounts greater than 45 milligrams/litre, and that the environmental conditions in Lake Nakuru are not optimal for the growth and reproduction of the fish.
According to the World Health Organization, the recommended level of nitrate is less than 45 milligrams/litre. Anything above the recommended levels is considered not fit for aquatic life.
“The levels of Chromium exceed the FAO limit of 0.14mg/l. The other toxic metals are of concern,” various researchers have noted.
The detection of heavy metals in the fish even in small concentrations, researchers say, may not have an immediate health threat on consumers of fish and fish products from Lake Nakuru, but will likely have adverse effects if there is prolonged consumption of the fish species since the heavy metals contents will accumulate in the body.
The researchers further blame the pollution of Lake Nakuru for the sad scenario, noting that over 65 percent of human waste ends up in the lake untreated, due to inefficient transport and treatment. Solid waste, storm water and drainage management is also limited.
This is the reason that the lake is completely anoxic and cannot support life, particularly in the mid-lake and at depths below one meter from the surface,” one report stated.
By Anne Mwale and Veronica Ngina
