Alarm over sick birds at Bogoria
Thursday, April 5, 2001
The Nation (Nairobi,Kenya) Michael Njuguna
Thousands of newly-hatched flamingo chicks are landing at Lake Bogoria from Lake Natron in Tanzania where successful breeding takes place continually. But scores of them are unable to fly, providing easy prey to marabou storks.
The good news is that adult flamingoes are building nests and laying eggs at Lake Nakuru for the first time in 65 years. About a million flamingoes, the highest number in recent times, are currently residing on the shores of Lake Nakuru, forming a glorious mass of pink against the brackish waters. The waters sustain heavy algal blooms of spirulina platensis - the blue-green algae on which lesser flamingoes feed.
The Lake Nakuru National Park, with its rhino sanctuary and a large species of birds and terrestrial animals, is the place tourists should be heading. The beauty is irresistible.
The Kenya Wildlife Service (KWS) Director, Mr Nehemiah Rotich, told reporters that the 188 square kilometre park is now one of the leading parks in income generation. It is second only to the vast Amboseli. However, there are fears that pollutants are finding their way into the lake's waters.
Dr Gedion Motelin of the Department of Animal Health, Egerton University, told the Nation that tests carried out on dead flamingoes in 1993/95 at Lake Bogoria revealed traces of heavy metals, including lead, chromium, arsenic and mercury.
Traces of organo-chlorines were also discovered in body tissues. Dr Motelin said the flamingoes must have ingested the chemicals at Lake Nakuru. Other conservationists argue that it was possible that flamingoes ingested contaminants within lakes in other countries.
Toxic chemicals such as DDT, which is banned in Kenya, is reportedly used in Ethiopia. "Flamingos have a vast home range. Some of their feeding sites in Ethiopia are close to factories, which could be discharging harmful effluent," he said.
Dr Motelin said the lesser flamingo (dominant in Rift Valley lakes) also ingest and digest other micro-organisms that grow in saline waters. These include other blue-green algae and diatoms.
The don said that during the 1993/95 period, most deaths at Lake Bogoria occurred at landing sites. There are multiple problems but the stress of flying was identified as one of the major causes of deaths. (among birds which had ingested toxic chemicals at Lake Nakuru).
The question now is, why did the birds succumb to flight stress at Lake Bogoria and not at Lake Nakuru? Organo-chlorines find their way into Nakuru water systems from nearby farms which use large quantities of fertilizers, pesticides and agro-chemicals.
Lake Bogoria is about 104 kilometres from Nakuru town (by road) but the flamingoes' flight covers about 60 kilometres. The 290 square kilometre Lake Bogoria is a comparatively clean habitat. This is partly because it is not located next to an urban area.
But organo-chlorines can enter the lake through River Sandai, which passes through farmlands in Laikipia district. Dr Motelin said two toxic alga-microcystis and anabena had also been discovered in the flamingo feeding sites.
While the Lake Nakuru National Park warden, Ms Catherine Wekesa, and her team say they are doing their best to protect flora and fauna at the park, the problems threatening the park are coming from without.
The park management can do little about the Nakuru Municipal Dump, located on a faultline on the lower slopes of Menengai Hill. It is suspected that leaching could be taking place at the dump because the wastes are not compacted.
The wastes are also not classified, nor dumped at designated sections as required.
Mr Daniel Koros of the World Wide Fund for Nature (WWF) confirms a report by another WWF researcher, Mr Jackson Raini, that traces of heavy metals have been discovered in water sources in Nakuru.
He said during a seminar on Environmental Education and Religion held at the KWS education centre recently that Lake Nakuru National Park - a wetland of international importance - had 250 species of birds, 50 different species of mammals and 350 species of plants.
He cautioned that the lake, the first in Kenya to be listed as a Ramsar site, is threatened by pollution and unprecedented deforestation of the catchment basin. Large quantities of silt is now being swept in from the forests excised in recent years to create human settlements.
The Sh800 million Nakuru Sewage Rehabilitation and Extension Project was designed to reduce the biological oxygen demand (BOD) concentration from 500 milligrams per litre to 10mg/l in the effluent for the final stage to Lake Nakuru. The project was funded by the Japanese Government and handed over to the Kenya Government in 1997.
At the time, the BOD value at the sewage intake ranged from 800 to 1,000. This was a high level of pollution. The then Japanese Ambassador to Kenya, Dr Shinsuke Horiuchi, who presided over the handing-over ceremony in March 1997, cautioned on the dangers of polluting Lake Nakuru.
"Indiscriminate discharge by factories and homes must be stopped. Some discharge at the source registered between 2,000 and 3,000 BOD, which means that all waste liquid by factories is dumped without any effort to control it."
The envoy said the new plant was a sewage plant and not a plant designed to clean industrial waste at source. "Unless the community controls the polluted effluence as required by the Trade Effluent Laws, no sewage plant can guarantee to maintain clean water in the lake."
When the Nation visited Lake Bogoria recently, an employee of the reserve said arrival of young flamingos started last month and that they had been landing at night. A couple of young birds were seen limping soon after landing in the hot water.
The flamingoes have chosen feeding sites close to the hot springs while the older birds feed farther away. About 20 dead flamingoes were counted, but there were no signs of mass deaths as was the case in 1999.
A flock of marabou storks was found feeding on dead flamingoes. No carcasses of young birds were sighted.
Previous tests on dead flamingoes revealed traces of heavy metals, including lead, chromium, arsenic and mercury