Current view: Text account
Site description (2022 baseline):
Site location and context
The Tana River delta is located in Tana River and Lamu Counties in Kenya’s North Coast, about 182 kilometres north of the coastal town of Mombasa. The delta is a vast wetland complex with a patchwork of palm savannah, seasonally flooded grassland, forest fragments, lakes, marine wetlands and the river itself (GRAIN et al., 2014). It is a low-lying area, triangular in shape, with its apex at Lake Bilisa (north of Garsen) and its base, a 50 km stretch of beach along Ungwana (or Formosa) Bay, stretching from Kipini in the north-east to Mto Kilifi in the south-west. The area is bound by higher land to the east, west and south by a dune system bordering the Indian Ocean. It forms the interface between the river and the ocean with fresh water, brackish lakes and streams, freshwater and saline grasslands and wetlands, and succession stages of forest and woodland on the riverbanks and the dune ridges parallel to the shore (Robertson & Luke 1993). The entire floodplain in the lower parts is covered by alluvial sediments, transported and deposited during the river’s annual flooding. These lie over quaternary sediments, including marine sands, mud, and coral breccia. The area receives rainfall ranging from 1,000 mm per year at Kipini to less than 600 mm at Garsen. Flooding in the delta results from rain falling upstream in the Aberdare Mountains (KE001), the crests of Mount Kenya (KE005), and Nyambene Hills. Significant floods typically occur in April–May, while minor floods are experienced during the short rains period experienced in October–November. Due to climate change, the flooding’s timing, extent and duration vary significantly from year to year.
See Box and Table 3 for key species.
The importance of the Tana River Delta lies in its habitats’ expanse, intactness, variety and productivity. The area hosts rich biodiversity of global importance. In recent surveys, it was found that the delta hosts more than 336 bird species. 4 CR (White-backed Vulture Gyps africanus CR, Rüppell’s Vulture Gyps rueppelli CR, Hooded Vulture Necrosyrtes monachus CR, and White-headed Vulture Trigonoceps occipitalis CR) 3 EN (Martial Eagle Polemaetus bellicosus, Bateleur Terathopius ecaudatus, and Lappet-faced Vulture Torgos tracheliotos), 1 VU (Tawny Eagle Aquila rapax), 10 NT, 316 LC, and 1 DD. The list consists of Afrotropical Migrants, Oriental Migrants, Palearctic Migrants, resident and those that only part of the population is resident, (Ronald 2020, 2021).
Large mammals have been recorded, including the Endangered African Savanna Elephant (Loxodonta africana), two Endemic and Critically Endangered primates- (Cercocebus galeritus) and the Tana River Red Colobus (Piliocolobus rufomitratus). The population range for the two critically endangered monkey species was 377 – 429 individuals for the Tana River red colobus and 671– 873 for the Tana River mangabey. The Tana River Red Colobus is among the 25 most endangered primates in the world 2002–2018 (Kivai et al., 2021; Schwitzer, et al.,2017).
A number of herpetofauna species of conservation concern are also presented- five species of threatened marine turtles, Near endemic terrestrial Tana River Leaf-toed Gecko (Hemidactylus modestus DD), the burrowing Tana Writhing Skink (Mochlus tanae LC), the semi-fossorial Mabuya-like Writhing Skink (Mochlus mabuiiforme DD), Rare coastal Endemic Kaya Mrima Tree Gecko (Hemidactylus mrimaensis). On snakes we have the burrowing Tana Worm Snake (Myriopholis tanae DD) and the Tana Delta Crowned (Meizodon krameri DD). The amphibians include the near endemic Tana Mud Caecilian (Schistometopum gregorii LC) (Malonza and Nyamache 2021).
A total of 25 species of fish have been recorded in the Tana Delta. Two species are Critically Endangered-Tana labeo (Labeo mesops). African mottled eel (Anguilla bengalensis labiata) Not Evaluated. The most abundant fish species in the Tana delta is recorded to be African sharptooth catfish (Clarias gariepinus LC), Labeo gregorii (LC) and Oreochromis spirulus. Least abundant species were Terapon jarbua (LC) and Labeo mesops (CR), Pellona ditchella, Protopterus aethiopicus (LC), Anguilla bengalensis labiata and Parailia somalensis (DD) (Edward and Joseph 2021).
103 butterfly species recorded in Tana Delta fall in two IUCN categories, with 53 under Least Concern (LC) and 44 under Not Evaluated (NE). Thirty-four (34) species of bees recorded- The bees recorded in Tana Delta are in three IUCN categories; one is of Least Concern (LC), one under Data Deficient and fourteen are under the Not Evaluated (NE) category (Esther et al., 2021).
There are 320 plant species in the Lower Tana River; 58 of them tree species, of which two are considered Critically Endangered in a global sense. Twenty one per cent of the plants are of conservation concern, (Odhengo et al., 2014a). The mangroves provide vitally important spawning and nursery grounds for many fish species and crustaceans. The extensive mangrove forests include the only significant stands in Kenya of the plant Heritiera littoralis LC , and two other plant species that are considered threatened Xylocarpus granatum LC and Bruguiera gymnorhiza LC (Field et al., 2020).
The Delta contains many habitats, including riverine forest, grassland, woodland, bushland, lakes, mangroves, dunes, beaches, estuaries and coastal waters. Small fragments of riverine forest occur along the present or former river courses. Seasonally flooded floodplain grasslands cover c.67,000 ha of the delta. West of the floodplain is diverse bushland. Wooded bushland or grassland, with fire-resistant tree species, occupies a broad swathe east of the floodplain, merging into the Boni forest vegetation to the north. Other bushland associations form a complex mosaic with the floodplain grasslands, parallel to the coast along Ungwana Bay, run lines of high dunes, some as high as 37 m above sea level. These are covered by distinctive vegetation, a dense thicket dominated by Dombeya sp. and Grewia similis. In the valleys, the thicket mingles with taller trees, including various palms. Palms are prominent in many places. Some areas, especially those cleared and burned in the past, form substantial tracts of palm-bushed grassland. Tall mangrove forest grows at Kipini in the Tana estuary and along the network of channels further south. As well as seasonal wetlands in the oxbows and floodplain depressions, the delta contains several near-permanent lakes and marshes. Some of these dry out at some time of the year, while others, like Lake Shakababo and Bilisa, maintain true aquatic plants and good populations of several species of fish.
The Tana River Delta is inhabited by three major communities – Pokomo(44%), Orma(44%) and Wardei(8%). Other ethnic groups(including Bajuni, Luo, Luhya, Wataa/Sanye, Boni, Malakote and Munyoyaya and more recently Giriama and Somali) account for the remaining 4%. The Pokomo people are subsistence farmers, while the Orma and Wardei people are pastoralists who have used the delta for centuries (Odhengo et al., 2014a). Luo and Luhya immigrants to the area are responsible for an active and thriving fishery, while Orma pastoralists use the wetlands as dry-season grazing areas for their livestock. Fishermen also camp for days or weeks while catching, salting and drying fish on the coral outcrops of Mwamba Ziwayuu, c.10 km offshore from Kipini. The Pokomo cultivate a narrow strip on either side of the river and around the seasonal and permanent wetlands (Odhengo et al., 2014).
Pressure/threats to key biodiversity
- Destruction and loss of some key habitats as a result of over-exploitation, poor land use practices, encroachment and unplanned and unregulated human settlement, and unsustainable agricultural development.
- Declining water quality due to increased pollution and siltation from the upper catchment.
- Inadequate communication, education and awareness on delta management issues.
- Uncoordinated research and monitoring programs that do not adequately inform the management of delta resources on issues affecting them.
- Inadequate mechanisms to address risk management issues affecting the delta such as climate change, drought, floods, tsunami and storm surges.
- Inadequate partnership and cooperation between government, private sector and non-governmental organizations.
- Inadequate actions to preserve and conserve natural and cultural heritage within the delta ecosystem.
Conservation responses/actions for key biodiversity
- Setting up of guiding policy framework- Tana River Delta Land Use Plan to guide development through green value chain
- support to sustainable Land Management through establishment of 116,768 Indigenous Community Conserved Area (ICCA) Forest and Landscape Restoration, that is guided by findings of Restoration Opportunity Assessment Methodology (ROAM).
- Protection of the wetlands and adjacent riparian vegetation.
- Improve biodiversity knowledge through research and surveys.
- Support establishment community structures (Site Support Groups, Community Forest Association, and Village Natural Resource Committees) to enhance sustainable landscape management.
- Promote Ecosystem Based Adaptation best practices.
- Establishment of Nature Based Enterprises as conservation incentives for local communities.
- Establishment of Green Industrial Park whose aim is promoting sustainable economic growth and protection of the environment, creating new jobs and livelihoods and boosting the regional and national economy.
- Promotion of ecotourism.
The Tana River Delta has five National Forest Reserves- Chara, Kilelengwani, Kipini, Ozi, and Hewani-Onkolde Forest Reserves where Community Forest Associations have been set up in 2020 as part of devolved forestry functions. The rest of the area falls within community management structures in the Indigenous Community Conservation Area framework.
Land in the Tana River Delta has a different land tenure and ownership system. The Tana River delta has 5 National Forest Reserves- Chara, Kilelengwani, Kipini, Ozi, and Hewani-Onkolde Forest Reserves, where Community Forest Associations have been set up. In addition, part of the delta has Community Conservancy- Lower Tana Delta Conservancy. The rest of the land area is under community land held in Trust by the Tana River County government and national government-where crop cultivation and settlement exist.
Site access / Land-owner requests
Site access/ Land-owner requests are highly dependent on the land ownership. If the site of interest is owned by an individual, then he/she will authorize it; if owned by the community, laid down community procedures will be followed.
We acknowledge efforts by the different teams of experts working tirelessly to ensure that the Tana Delta Complex ecosystem is well managed to assure a steady flow of ecosystem services and thriving of healthy biodiversity and the ecosystem at large.
Recommended citation
BirdLife International (2024) Important Bird Area factsheet: Tana River Delta (Kenya). Downloaded from
https://datazone.birdlife.org/site/factsheet/tana-river-delta-iba-kenya on 22/12/2024.
