Flamingos Die in African Rift Valley Lakes

Back to Map Page March, 2000 Lake Bogoria National Reserve, Kenya   Image source: B. Barker.   Flocks of pink flamingos are a beautiful and world-famous sight on shallow, salty Lake Bogoria in the Rift Valley of Kenya. A million of the stately birds congregate in the salty mudflats to feed on the algae that abound in the briny water. But this year, flamingos are dying by the hundreds every day. Since July of 1999, at least 30,000 of the birds have perished, according to a report in the Washington Post. Scientists believe the cause is heavy metal pollution in Lake Nakuru, another large, shallow lake, 60 miles to the south, where the flamingos have spent much of their lives. Both Lake Bogoria and Lake Nakuru are inland basins---that is, they collect rainwater and stream runoff from a large surrounding area, but they have no outlet. Water evaporates in the equatorial sun, but salts, heavy metals, pesticides---including DDT---and other contaminants remain in the lake, gradually becoming more and more concentrated. Heavy metals and pesticides, in particular, are reaching toxic concentrations. The contaminants have many sources, but an important contributor is a nearby city of 360,000 whose sewage and industrial effluent drains into Lake Nakuru. Mercury, arsenic, cadmium, lead, and chromium have all been found in the carcasses of expired birds. A battery factory, a tannery, and other industrial sites probably produced these contaminants, which have gradually poisoned the flamingoes. Even breeding activity appears to have stopped in the last 2 to 3 years, likely a response to stress and ill health. Low populations of crustaceans in Lake Nakuru appear to have driven the flamingo flocks north to Lake Bogoria since 1998, but the current deaths may result from poisoning while the birds were still at Lake Nakuru. Local industries are making efforts to clean up their effluent, and some parts of Lake Nakuru are becoming cleaner as contaminants settle into the mud and become buried. The presence of the national park in that areaŅand a keen interest in maintaining capital flow from tourismŅare incentives for restoring water quality and rebuilding the flamingo populations despite the poverty of the region. To learn more, see these related websites: Flamingo article from International Wildlife, January 1999 Conserving Lake Nakuru, story from World Wide Fund for Nature Research on Lesser Flamingos, compilation of results (a little old) Kenya information: geography, geology, etc. To read more, see: Environmental Science, A Global Concern, Cunningham and Saigo, 6th ed. Ecotourism, pp. 340-41, 344-45 Water pollution, pp. 447-55 Inorganic pollutants (metals, salts, acids), pp. 452-53 Environmental Science, A Study of Interrelationships, Enger and Smith, 7th ed. Industrial water pollution, p. 287 Preserving scenic water areas and wildlife habitats, p. 297 Water use and pollution in industrialized and developing countries, p. 289 Back to Map Page feedback form | permissions | international | locate your campus rep | request a review copy digital solutions | publish with us | customer service | mhhe home Copyright ©2001 The McGraw-Hill Companies. Any use is subject to the Terms of Use and Privacy Policy. McGraw-Hill Higher Education is one of the many fine businesses of the The McGraw-Hill Companies.