Lake Natron, the East African Halophytic situated along the Great Rift Valley in Tanzania is a saline soda lake. This Ramsar wetland site, principally fed by Southern Ewaso Ngiro River and mineral hot springs provides a pretty inhospitable and inappropriate environment for the majority of the plants and animals by virtue of its high temperature and salinity and rapidly changing salinity post rains. This very shallow lake, which runs about 57 kilometers long and is about 22 kilometers wide is home to flocks of both lesser as well as greater flamingos which breed on the mud flats surrounding the lake regardless of its high salinity.
The blue-green algae filtered out by the lesser flamingos and the copepod larvae found in the shallow waters for the greater flamingos are its source of nutrition. The lake witnesses a very erratic rainfall pattern with most of the rainfall in between the months of December and May followed by an extended dry period with an average temperature of over 40 degree Celsius causing high rates of water loss due to high evaporation rates. This climatic desiccation over the years has caused the lake to become saline with high contents of sodium carbonate decahydrate and sodium sesquicarbonate dehydrate. Adding to the alkalinity of the lake are the sodic soils resulting from the volcanic activity that form the bed of the lakes. Lake Natron is rich in sodium carbonate and is hence highly alkaline with a pH of about 10.5 and is hence viscous to touch.
The lake is surrounded by a few halophytic plants like Cyperus laevigatus, Juncus maritimus, etc. which tend to grow on the saline soil around the lake. Though the lake lacks macrophytic vegetation but is highly productive in terms of algae with blue-green algae species like spirulina spp. dominating the saline water. The saturated salt water of this saline lake with temperature reaching as high as 41degree Celsius near the hot mineral spring and erratic rainfall causing dramatic change in pH due to flooding of the lake with cold, slightly acidic water makes the lake difficult for life to thrive in.
The mud flats too are just as difficult and inhospitable for mammals due to strong winds, extreme temperatures and scarce vegetation. However, populations of certain species are well adapted to this environment. Oreochromis alcalica or commonly known as tilapia inhabitate the lake in abundance. This small fish is found on the edges of the inlets to the hot springs. Tilapia is well acclimatized to the high salinity, temperature and changing conditions as a result of the slightly acidic rains.
Lake Natron also has distinctively high populations of many birds endemic to the wetlands. The lake having the highest concentration of the flamingos in the whole of East Africa is the only regular ground of breeding for the lesser flamingos (Phoeniconaias minor) in Africa.
The major threat surrounding Lake Natron is the hydroelectric power project on Ewaso Ngiro River by the government of Kenya. The project is likely to potentially alter the ecology and hydrology of the lake due to changed patterns in water flow and hence threaten the world’s most secure and largest breeding ground for the lesser flamingos. The lake is further threatened by the small sodium bicarbonate extraction plant. The lake is inaccessible to the extent that it was only discovered somewhere in 1954 and hence has hence in past not been subjected to human fragmentation. The lake became an active development site, for increasing tourist attraction and also for the extraction of soda ash which was greatly refuted as it greatly threatened the fragile ecosystem and the vulnerable population of the lesser flamingos.
The lake does not fall in the network of protected areas, moreover the area surrounding the lake though regulated, is allowed for hunting and hence the ecosystem lacks formal protection as a whole. The increasing danger for the lake was highlighted by renowned photographer Nick Brandt, who captured in his book “Across the Ravaged Land” haunting images of Lake Natron. He found remains of creatures like Flamingos, Bat, etc. with sharp outlining of sodium carbonate deposits around the bodies of the creatures on the shoreline of the lake. Brandt repositioned the dead creatures in living positions as though the lake converted the creatures into stoned statues.
These photographs raised an alarm against the increasing threat to the fragile breeding ground for the endangered lesser flamingos. The lesser flamingos are endangered and highly vulnerable to changes and the soda extraction plant threatens their survival and may drive it to extinction. The active participation and involvement of the villagers surrounding the lake for the protection of the lake played a major role in protection of this very fragile ecosystem. The Wildlife Conservation Society of Tanzania (WCST) hence recommended the development of the tourism industry which was sensitive to environment over the soda extraction plant proposed by a multinational company.
WCST for this reason called in for the active involvement of the government and stakeholders. The purpose of which was to enhance tourism by taking advantage of the aesthetics and beautiful biodiversity of the region to ensure sustainable income for the local community and conservation of the beautiful fragile wildlife it supports.
Anushua is currently pursuing her masters in Environment Management from Guru Gobind Singh Indraprastha University, Delhi having completed her graduation in chemistry from Sri Venkateswara College, University of Delhi. She did her schooling from Ann Mary, Dehradun which instilled in her the passion for environment. She has particular interest in energy and water pollution domain and loves to read and write about researches in the field of science.