Kenya's Pink Flamingos Weighed Down by Heavy Metals
By Jennifer Wanjiru
NAKURU, Kenya, July 16, 2001 (ENS) - Veterinary pathologists in Kenya have identified heavy metals as the leading cause of massive deaths of flamingos in two Rift Valley Lakes of Kenya, and warned that the scenic pink birds of Lakes Nakuru and Bogoria remain threatened unless the lakes are cleared of pollutants.
"The presence of heavy metals in the birds tissue is alarming," cautioned Dr. Gideon Motelin, a veterinary pathologist at Egerton University who last month conducted a three-day fact finding mission in the two lakes.
Motelin is leading Kenyan researcher on flamingos. The Kenya Wildlife Service (KWS) acknowledges that Lake Bogoria is the "worst affected" but gave no data on the number of birds that have died. Journalists have counted hundreds of birds' carcasses littering the shores of both lakes.
But the wildlife agency played down pollution as the cause of deaths. "If it's a question of pollution, why is it affecting both Lakes. We could understand if it was only in Nakuru but Bogoria is far away from industries," said Daniel Njaga, a communications officer at KWS.
A group of scientists have been camping on the shores of Lake Bogoria assessing the situation and brainstorming on how to conserve it as a wetland site. But it is the continuing death of flamingos that kept the entire team on its toes.
"We are concerned because this could be a catastrophe," said Motelin. The concentration of individual elements may not be high enough to cause death he explained that "combinations of poisons could cause death as they affect different sensitive organs of the body."
"Some of the birds had lesions in the spleen and others in the kidney. The lesions suggest toxicosis as the cause of death and incapacity," Dr. Motelin explained. "If we are to arrest the situation, pollution has to cease."
Experts warn that the level of pollution in Kenyan lakes is growing due to collapse of sewage works in many urban centers and growth of industries whose effluent flow into the lakes. The rise of horticultural farms along most of the Rift Valley lakes have also caused fertilizers to run off into the lakes.
Dr. Motelin said cadmium, a metal found in the birds' tissues, as "dangerous as it replaces calcium in the bones making them brittle."
"This may be one of the reasons why birds are finding it difficult to co-ordinate in the water. The birds have become weak and cannot manage to migrate from different lakes without succumbing," said Dr. Thampy.
Flamingos can fly up to 300 kilometers in a day, and researchers also think the deaths could be as a result of "flying stress" Dr. Thampy says that the clinical signs of the current birds resemble episodes in 1993, 1995 and 2000 when similar deaths occurred. He said the current deaths began mid-May this year.
The preliminary report indicates that migration and breeding, plus organochlorines are other cause of deaths. Although Kenya Wildlife Society dismisses the allegation of pollution as the cause of death, Dr. Motelin believes the birds ingested toxic chemicals at the Nakuru Lake.
Organochlorines find their way into Lake Nakuru through water systems from nearby farms, which use large quantities of fertilizers, pesticides and agrochemicals.
Compared to Lake Nakuru, the 290 square kilometer Lake Bogoria is in a comparatively clean condition and is away from industrial pollutants. The flamingos fly the 60 kilometer distance between the two lakes regularly.
Organochlorines discovered in flamingo body tissues can enter Lake Bogoria through River Sandai, which passes through farmlands in Laikipia district. The toxic chemical DDT, which is banned in Kenya, is reportedly used in Ethiopia.
"It is true that flamingos have a vast home range. Some of their feeding sites in Ethiopia are close to factories, which could be discharging harmful effluent," said Montelin.
The Kenya Wildlife Service defends Lake Nakuru, saying the lake is not the source of these pollutants. "If that was the case it should affect other birds and animals that use the lakes as a resource," said Njaga. "In Lake Nakuru we have about 400 species of birds including the terrestrial birds.
"Why are the other water birds like the pelicans and the ducks not affected? And finally, If it is pollution why is it affecting a small number and only the lesser flamingos?" he asks.
The KWS says the situation is environmental, associated with ecology rather than pollution. Said Njaga, "I would attribute the cause of the deaths to regular changes in the water volume. Since El Nino there have been adjustments of water volume that affect water chemistry, its salinity, productivity, bio-chemical oxygen demand and even nutrients. When the water volume drops, the level of salinity rises which may render flamingos' food toxic."
Still, this does not ease WWF's concern that if the majestic birds continue to decline by 20 percent every two decades, "The entire flamingo population may be wiped out in a 100 years," the group warns.