Two and a half million Lesser Flamingos may lose their breeding grounds at Lake Natron if plans go ahead to build a soda extraction facility on the lake shore, resulting in habitat loss and degradation and associated pollution.
Lake Natron in Tanzania is an important wildlife area that supports a thriving Masai community and large mammal and bird populations. It is internationally recognised as a valuable wetland site by the Ramsar Convention and as an Important Bird Area (IBA) by BirdLife International (Fishpool and Evans 2001, TME 2007). With vast isolated salt flats providing safety from predators and ready supplies of freshwater and food from lakeside springs and cyanobacteria-rich hot saline waters, Lake Natron is a perfect breeding site for Lesser Flamingo Phoeniconaias minor, classified as Near Threatened on the 2008 IUCN Red List. Indeed it is the only known site in East Africa where the species regularly nests, with 2.5 million individuals (75 % of the global population) flocking to the area every year (Koenig 2006, BirdLife International 2008). In 2007, plans were unveiled to build a soda (sodium carbonate) extraction facility on the shores of the lake, a proposition that would significantly change its hydrology and chemical composition rendering it unsuitable for Lesser Flamingo (Fishpool and Evans 2001, Burton et al. 2007).
Covering a wide area and including new road, rail and air links, a coal-fired power station and modern housing, the facility is predicted to extract more than 100,000 litres of freshwater and 550,000 litres of brine from the lake every hour and to pump back over 400 metric tons of depleted brine and 90 metric tons of mud. These effluents could significantly lower the salinity of the lake and increase its turbidity, lowering the productivity of cyanobacteria such that the lake would support fewer flamingos. Freshwater sources and the lake water itself would also become heavily polluted with domestic and industrial waste, sewage and toxic chemical seepage from storage areas. Flamingos prefer mud sites for nesting, but soda ash extraction would deepen the lake and flood these sites, making them unusable. The development would also compete for critical freshwater resources needed by the flamingos for bathing and drinking, and could cause other mudflats and wetlands surrounding Lake Natron to dry out and cease to act as predator deterrents. Lesser Flamingos would be threatened by disturbance from heavy machinery, vehicles, construction activities and aircraft noise associated with the facility. New scavenging predators, such as Marabou Stork Leptoptilos crumeniferus, could be attracted to the area and an increase in the human population twinned with improvements to the surrounding infrastructure could result in an increase in illegal poaching from nesting colonies (Koenig 2006, Burton et al. 2007, TME 2007).
The tourist industry at Lake Natron would also suffer if Lesser Flamingos—one of the chief attractions—were forced to leave, and concerns have been raised over the consequent loss of local livelihoods (Burton et al. 2007, TME 2007). Protests from local people and conservation organisations have resulted in the development being postponed for now, but Lesser Flamingos are not safe yet. Unless the developers abandon their plans for Lake Natron, the species could soon become globally threatened through the loss of its most important breeding site.
Related Case Studies in other sections
BirdLife International (2008) Soda extraction plant at Lake Natron, Tanzania, threatens East Africa's Lesser Flamingos. Presented as part of the BirdLife State of the world's birds website. Available from: http://www.birdlife.org/datazone/sowb/casestudy/153. Checked: 04/09/2015
|Key message: Infrastructure development, notably for residential and commercial purposes, threatens biodiversity|