Tanzania is endowed with salty alkaline (soda) lakes all found within the Rift Valley, which support a rich lacustrine wildlife, some of which are endemic and highly specialized to the unique environment within one particular lake. They form part of the East African Rift Valley System (EARS), a continental-scale tectonic structure that has evolved through Earths’ history to the present scenic and architectural beauty of its geo-morphological features, characterized by steep fault escarpments, deep gorges, cinder cones and craters on the rift floor, gushing geysers and hot springs.
Lake Natron is one of salty alkaline lake found in Engare Sero village. Lake Natron area is recognized as an important Ramsar Wetland internationally listed as Tanzania’s second Ramsar site in 2001. Nonetheless its importance can be traced back from early 1960s when it started to feature as the only regular breeding area for the 2-4 million Lesser Flamingos (Phoeniconaias minor) in East Africa (Soussa et al., 2010); accounting for 75% of the global population (NORCONSULT, 2007). Tourists visit Lake Natron for viewing flamingos and the surrounding ecosystem (Plate 54). Lake Natron and its surrounding ecosystem are extremely important for biodiversity conservation, ecosystem services and for supporting the livelihoods of the local communities, which depend on pastoralism, culture tourism, small mining of the soda, and small-scale irrigation.
Plate 54: Flamingos are the main attraction of the Lake Natron
The catchment area of Lake Natron has a hot climate in low altitude areas and a cooler climate in higher altitude areas. On average, temperatures range from 20°C to 35°C. Rainfall ranges from less than 500mm in lowlands to 900mm at higher elevations (NORCONSULT, 2007). Unlike for rainfall, the potential evapotranspiration increases towards the lowland area, ranging from less than 1100 mm per year at higher elevations to about 1900mm in the Lake zone. Thus Lake Natron has a high level of evaporation with high moisture deficit between June and November, making it one of the hottest and driest places in northern Tanzania. In January and February temperatures are often above 40º C. The high temperatures coupled with low rainfall within the lower Gregory Rift create a negative water balance situation of about 1400mm at the Lake floor. The system relies on inflows from both rivers and springs to maintain perennial pools of water within the Lake.
Hot Spring Water
The hot spring water occurs along the Lake Natron shore, almost 30 km from Engare Sero village. The spring effuse hot water related to the active volcano of the area. The area where the hot water are produced has approximately diameter of 10 meter square producing water of around 60º C on the surface (Plate 55). This is the only known hot water spring in the area/lake. Water produced has high content of salty which have attracted many flamingos nearly around (see Plate 54 above).
Plate 55: Hot spring water on the Lake Natron shore
Peninj is a Plio-Pleistocene sedimentary unit located in the southwest sector of Magadi-Natron basin in the south of Kenya and in the north of Tanzania. The site is composed of deep sequence fluvial and lake deposits with volcanic tuff, resting on a thick layer of basalt (Sembu lavas) that were deposited between 3.5, 2.0 and 1.9-1.77 mya (million years ago).
Early investigations by Isaac and his team (Isaac, 1965, 1967) recovered a significant assemblage of fossil mammals, Acheulian artifacts, and a hominid jaw fragment attributed to Australopithecus boisei at Peninj site (Leakey and Leakey, 1964). These materials were recovered from the Humbu Formation dated to 1.7 million bp (Manega, 1993). The archaeological, zoorachaeological and taphonomic characteristics of this site have attracted many scientists investigating our cultural history.