The East African manatee according to MammalMAP
Meet the West African manatee (Trichechus senegalensis). A cousin of the dugong, manatees are found along the West African coastline between Angola and Senegal, inhabiting coastal waters and rivers. They are comfortable in both salt and fresh water, but seem to prefer shallow estuaries and swamps. These mega-herbivores feed on huge quantities of aquatic plants – up to 8000 kg/year – so much so that some have proposed that this exceptional feeding ability makes them perfect for the job of Specialised Aquatic Weed Eaters! As with many African mammals, humans are their worst enemy and greatest threat. Illegal hunting of manatees for their palatable meat, and for their skin, bones and oil has led to significant declines in numbers in some areas. Manatees sometimes also become accidentally entangled in fishing nets, which compromises their survival, even if they escape. Perhaps worse still is that – because fishing nets may get damaged when manatees are accidentally entrapped – fisherman in some areas conduct manatee hunts to prevent net damage. Manatees also clash with people when, during the rainy season, they roam on land and destroy crops. For all of these reasons, manatees are now listed as Vulnerable on CITES, and their populations need to be carefully monitored, managed and protected. For more information go to the MammalMAP virtual museum or blog.
Occurrence in major rivers from north to south including lakes within these river systems: the Senegal, Saloum, Gambia, Casamance, Cacheu, Mansoa, Geba, Grande de Bulba, Tombali, Cacine, Kogon, Kondoure, Sierra Leone, Great Scarcies, Little Scarcies, Sherbro, Malem, Waanje, Sewa, Missunado, Cavally, St. Paul, Morro, St. John, Bandama, Niouniourou, Sassandra, Comoe, Bia, Tano, Volta, Mono, Oueme, Niger, Mekrou, Benue, Cross, Pie, Katsena Ala, Deb, Okigb, Issa, Bani, Akwayafe, del Rey, Ngosso, Andokat, Mene, Munaya, Wouri, Sanaga, Faro, Chari, Bamaingui, Bahr-Kieta, Logon, Mitml, Gabon, Ogoou, Nyanga, Lovanzi, Kouilou, Lom, Congo, Loge, Dande, Bengo, Cuanza, and Longa.
Occurrence in major lakes: Lake Guiers (Senegal); Lake Volta (Ghana); Inland Niger delta (Mali); Lake Lr and Lake de Trn (Chad); Lake Togo (Togo); Lake Aheme (Benin); Lake Onangue, Lake Ezanga, Lake Mandje (Cachimba) (Gabon).
Occurrence in major lagoons: Digbou Lagoon, Tadia Lagoon, Ebri Lagoon, Fresco Lagoon, Bandama Lagoon, Comoe Lagoon, (Ivory Coast); Sakumono Lagoon, Lake Songaw Lagoon, Keta Lagoon (Ghana), Grand Popo Lagoon, Lake Nokoue (Benin); Badagry Lagoon, Yewa Lagoon, Lagos Lagoon, Lekki Lagoon (Nigeria); Nkomi (Fernan Vaz) Lagoon, Ngowe (Iguela) Lagoon, Ndogo Lagoon, Banio Lagoon (Gabon); Conkouati Lagoon (Republic of the Congo); Massabi Lagoon (Cabinda).
Trichechus senegalensis occurs along the west coast of Africa. The Senegal River marks the northern limit of their range while the Cuanza River of Angola serves as the southern boundary.
Biogeographic Regions: ethiopian (Native ); atlantic ocean (Native )
West Coast of Africa from Senegal R. to Cuanza R
Other Physical Features: endothermic ; bilateral symmetry
Catalog Number: USNM A20907
Collection: Smithsonian Institution, National Museum of Natural History, Department of Vertebrate Zoology, Division of Mammals
Preparation: Skull; Skeleton
Collector(s): P. Du Chaillu
Locality: Gabon River, mouth (see Gray 1865:134), Gabon, Africa
- Syntype: Du Chaillu, P. B. 1861. Proceedings of the Boston Society of Natural History. 7: 367.
Habitat and Ecology
West and Central Africa contain a variety of suitable habitats for Manatees ranging from large and small rivers, coastal estuaries, freshwater and saltwater lagoons, shallow quiet coastal bays, lakes and reservoirs. Like T. manatus, T. senegalensis inhabits practically every accessible habitat (Powell 1996, Dodman et al. 2008). They have been observed or recorded from coastal areas, estuarine lagoons, large rivers that range from brackish to fresh water, freshwater lakes and the extreme upper reaches of rivers above cataracts. In general, their habitat requirements seem to be similar to T. manatus and require sheltered water with access to food and freshwater (Reep and Bonde 2006, Marsh et al. 2012). They may transit areas of unsheltered coast, but they are usually rare in these areas.
Optimal coastal habitats for Manatees, based on the movements of radio-tagged Manatees in Cte dIvoire and the number of reported sightings from other areas are: a). coastal lagoons with abundant growth of mangroves, aquatic plants or emergent herbaceous growth; b). estuarine areas of larger rivers with abundant mangroves (Rhizophora racemosa, R. harrisonii, R. mangle) in the lower reaches and lined with grasses, particularly Vossia and Echinochloa further upriver; and c). shallow (<3 m depth) and protected coastal areas with fringing mangroves or marine macrophytes, particularly Ruppia sp., Halodule wrightii or Cymodocea nodosa. In riverine habitats that have major fluctuations in flow rates and water levels, Manatees seem to prefer those areas that have access to deep pools or connecting lakes for refuge during the dry season and seasonally flood into swamps, savannas or forests with abundant grasses and sedges. In central African countries including Gabon and Republic of the Congo, Manatees use coastal lagoons during the dry season and then migrate up rivers to feed in flooded forests and lakes during the rainy season (Dodman et al. 2008, Keith Diagne unpublished data). Manatees that live extremely far inland in rivers in countries such as Senegal and Mali use specific feeding areas where year round aquatic and shoreline plants occur and also feed on freshwater mussels and fish, and then spread out onto flood plains during the rainy season to feed on emergent vegetation (Keith Diagne 2014).
African Manatees feed primarily on vegetation, and over 70 species of plants have been documented to date as Manatee food throughout their range (Villiers and Bessac 1948, Powell 1996, Reeves et al. 1988, Akoi 2004, Ogogo et al. 2013, Keith Diagne 2014). Some of the species more commonly observed being eaten by Manatees include: Vossia sp., Eichornia crassipes, Polygonum sp., Crinum natans, Nymphea sp., Cyperus papyrus, Cymodocea nodosa, Ceratophyllum demersum, Azolla sp., Echinochloa sp., Lemna sp., Myriophyllum sp., Pistia stratioties, Rhizophora sp, and Halodule wrightii. In countries including Senegal (Keith Diagne 2014), Cameroon (Takoukam and Koh Dimbot pers. comm.),and Sierra Leone (Reeves et al. 1988), Manatees are also known to eat small fish captured in fishermens nets. Manatees are also reported to eat freshwater and estuarine molluscs in many countries, including Senegal, The Gambia, Mali, Gabon, and Angola, and shell remains have been found in Manatee stomachs (Powell 1996, Collins et al. 2011, Keith Diagne 2014). Stable isotope analyses examined Manatee diet using samples from Gabon and Senegal and determined that molluscs and fish comprised 10% of Manatee average lifetime diet in Gabon, and 50% of diet in both freshwater and marine systems in Senegal (Keith Diagne 2014). Therefore, the African Manatee is not strictly herbivorous, but is omnivorous, a distinct difference from the other Manatee species.
Manatees can travel freely from salt to freshwater. They appear to prefer estuarine areas where there is little disturbance and the waters are shallow and calm. They can be found in marine habitats where there is relatively calm water and a source of freshwater. For example, in Senegal, The Gambia, and Guinea-Bissau, Manatees are attracted to a large network of freshwater seeps or springs that are found in nearshore marine habitats (Powell 1990).
T. senegalensis are mostly solitary, with mothers and calves forming the principal social unit. Manatees will often rest together in loose, small groups of two to ten individuals and mating herds have been observed in Gabon, Senegal, Nigeria and Sierra Leone (E. Eniang pers. comm., Keith Diagne unpublished data). In some African countries such as Cte dIvoire, Manatees feed principally at night and travel in the late afternoon and at night (Powell 1996), but in other countries such as Gabons Ndogo and Ngowe Lagoons and in the Casamance region of Senegal they can be seen travelling and feeding during all hours of day and night (Keith et al. 2006, Keith and Collins 2007, Keith Diagne unpublished data). They usually rest during the day in water that is 12 m deep and sometimes in the middle of a watercourse or hidden in mangrove roots or under natant vegetation. They make little disturbance while swimming. The Manatees that are easily sighted during daylight hours generally occur in places where little hunting occurs.
Trichechus senegalensis are found in shallow coastal wasters and freshwater rivers. They appear to prefer large, shallow estuaries and weedy swamps, and have been reported to avoid salt water (Nowak 1991 and Nishiwaki 1984). Their range is limited by temperature. They are rarely found in waters of less than 18 degrees celsius (Nowak 1991).
Habitat Regions: tropical ; saltwater or marine ; freshwater
Aquatic Biomes: rivers and streams; coastal ; brackish water
Other Habitat Features: estuarine
Trichechus senegalensis feeds primarily on aquatic vegetation, and adults may consume up to 8000kg per year. They may also feed on overhanging bank growth, and populations living in estuarine environments are reported to feed exclusively on mangroves (Nowak 1991). In many areas, local fishermen claim that Trichechus senegalensis are responsible for stealing fish from nets. However, this behavior has yet to be confirmed (Reeves et. al. 1988). Trichechus senegalensis are dependent upon microorganisms living in their large intestines to aid in the digestion of certain plant materials (Rathbun 1990).
Life History and Behavior
Perception Channels: tactile ; chemical
Trichechus senegalensis is a poorly studied species, and much of the information about their behavior and reproduction has been inferred based on their close similarity to the very well studied Trichechus manatus. They are capable of reproducing throughout the year; however, a peak in calving tends to occur in late spring or early summer (CMC 1997). Females are sexually mature as early as three years of age. A female in estrus is joined by a dozen or more males. Together they form a mating group in which copulation appears to occur at random (Save the Manatee Club 1997). Gestation lasts about 13 months and usually a single calf is born at a time, but twins do occur occasionally. Calves are born tail first, and they can swim on their own (CMC 1997). They feed from a pair of pectoral mammary glands. Trichechus senegalensis are believed to live to about 30 years of age, and females can bear young every three to five years (Sikes 1974 and CMC 1997).
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual
IUCN Red List Assessment
Red List Category
Red List Criteria
Using survey information from Cte d'Ivoire, Gabon, Guinea-Bissau, The Gambia, Senegal and Cameroon, and inferring what is known about Manatee habitat in other range states and Manatee density data for T. manatus, it is estimated that there are fewer than 10,000 Manatees in Africa. A continuing population decline of at least 10% in a90 year three generation period,is anticipated based on continuing and increasing anthropogenic threats (Vulnerable C1).
The African Manatee therefore qualifies for listing as Vulnerable.
- 2015Vulnerable (VU)
- Vulnerable (VU)
- 2006Vulnerable (VU)
- 1996Vulnerable (VU)
- 1994Vulnerable (V)
- 1990Vulnerable (V)
- 1988Vulnerable (V)
- 1986Vulnerable (V)
- 1965Status inadequately known-survey required or data sought
IUCN Red List of Threatened Species: vulnerable
Date Listed: 10/16/1979
Lead Region: Foreign (Region 10)
Where Listed: Entire
Population location: Entire
Listing status: T
For most current information and documents related to the conservation status and management of Trichechus senegalensis , see its USFWS Species Profile
There are no population estimates based on quantitative information. Nishiwaki et al. (1982) and Nishiwaki (1984) made a number of intuitive estimates for 15 countries, based primarily on interviews rather than direct surveys. Roth and Waitkuwait (1986) and Akoi (2004) made estimates of 750-800 Manatees for Cte d'Ivoire. In 1999 a report by ABE estimated the Manatee population in Benin at 125 individuals. There are no population number estimates for other countries at this time. The first genetics analyses for the species indicated high haplotype diversity and strong population structure but included samples from few individuals (Parr 2000, Parr and Duffield 2002, Vianna et al. 2006). More recent mitochondrial DNA analyses using 63 new samples from eight countries identified sixteen new control region and nine new cytochrome-b haplotypes for the species (Keith Diagne 2014). These are the first African Manatee genetic results from Senegal, Guinea, Mali, Ivory Coast and Benin. New haplotypes were characterized by high haplotype diversity, but low nucleotide diversity, indicating expansion after a period of low effective population size (Keith Diagne 2014). Phylogenetic trees identified two clades aligned geographically, indicating regional population separation likely due to low recent dispersal (Keith Diagne 2014). Ongoing mitochondrial and nuclear genetics analyses will probably allow for population estimates for Gabon and Senegal in the near future (Keith Diagne unpublished data). The Lake Chad population has probably been extirpated. It was reported that Manatees were gone from Lake Chad by 1929 (Hatt 1934, Salkind 1998), and although reports of them occurred in the Chari, Bamingui, Bahr-Kieta, and Logone Rivers leading into Lake Chad, Salkind (1998) reported that they were gone from these waterways as well. Today the drying and desertification of Lake Chad no longer provides much suitable habitat.
Available population information by country follows:
The species occurs in the Senegal River and its tributaries (Powell 1996); this river forms the border between Mauritania and Senegal. It is an infrequent inhabitant of the Diawling National Park, a wetland reserve of interconnecting streams, lakes and ponds adjacent to the Senegal River near the Diama dam (Perrin 2001). Manatees also probably inhabit the Gorgol Marigot, a large seasonally flooded tributary east of Kaedi.
In Senegal, the Manatee was reported as close to extinction by Navaza and Burnham (1998) but more recent work indicates that this is not the case (Diop 2006, Ba et al. 2008, L. Keith Diagne and Oceanium Dakar unpublished data). In the Senegal River Manatees are permanently isolated from the coast by the Diama Dam, located in the Senegal River east of St. Louis, and upstream by the Felou Dam in Kayes, Mali which prevents them from moving further eastward. Manatees are no longer reported west of the Diama dam in the Senegal River delta near St. Louis or coastally in this region (L. Keith Diagne unpublished data ). However, Manatees are sighted throughout the Senegal River east of the dam. Manatees are frequently seen in Lake Guiers year round, and in 2005 Tocc Tocc Community Reserve was created for their protection along the northwestern shore of Lake Guiers. In February 2014, Tocc Tocc Reserve was designated as Senegals fifth Ramsar site. During the rainy season when the Senegal River floods, Manatees are regularly seen near Kanel and Matam in eastern Senegal (Oceanium Dakar and L. Keith Diagne unpublished data). As flood waters recede during the dry season, Manatees become stranded in seasonal lakes at Wendou Kanel and the local people, along with assistance from the Senegalese NGO Oceanium Dakar, have been rescuing and releasing them back into the main Senegal River since 1984. Beginning in 2008, Manatees became trapped behind a new agricultural dam at Navel, near Matam, on the Senegal River. Five Manatees died as a result of entrapment behind the dam, and dam grates were removed in 2010. Seven live Manatees were rescued in early 2009 and satellite tags were attached to three adult Manatees that were rescued and released back into the Senegal River (L. Keith Diagne et al. unpublished data). These Manatees used over 265 km of the Senegal River to the north and south of the release site and made directed trips to feeding areas (L. Keith Diagne et al. unpublished data). Manatees are also frequently sighted at freshwater springs that occur along coastal Senegal from the Delta Saloum region to the southern border of the country and beyond into Guinea-Bissau. In the Senegal portion of the Gambia River, Manatees are reported as far inland as Niokolo-Koba National Park during the rainy season (Hill et al. 1998, Ba et al. 2008, P. Brillant pers. comm.), and they are also reported in this river across the border in Guinea (Thophile et al. 2008). In the Casamance River Manatees are reported as far east as Kolda, also at Basse Casamance National Park, and near the mouth of the river they can be seen daily drinking from a freshwater spring at Point St. George (Ba et al. 2008, L. Keith Diagne unpublished data). The only reports of recent Manatee hunting in Senegal are from the Delta Saloum region (IUCN and Parc National du Delta du Saloum 2005, L. Keith Diagne unpublished data).
In The Gambia, numbers are thought to have declined, but as of 1993 the Manatee was still numerous in the Gambia River. They have been fully protected for many years but are still believed to be hunted extensively (Perrin 2001, Jallow 2008). Manatees are reported throughout the Gambia River and its tributaries, and in Niumi National Park, Bao Bolong National Park, Kiang West National Park, and the Tanbi Wetlands Complex. There are no estimates of population numbers and little current research or conservation activities. In 2014 Manatee hunting was reported in Jareng in the Niamina East, and reports of incidentally caught Manatees were reported from Jareng as well as Tendaba in the Lower River Region (D. Saine pers. comm.). Manatees are also affected by the destruction of their habitat due to deforestation of mangroves (Jallow 2008).
Guinea-Bissau is considered likely have one of the largest Manatee populations in Africa, because of the relatively undisturbed state of its mangroves, wetlands and river systems (Schumann 1995, Powell 1996). Silva and Arajo (2001) found that Manatees occupied a wide variety of habitats and were most abundant around the Bijagos Archipelago. Based on interviews, a total of 256 sightings involving 439 individuals interviewed were reported. Powell (1996) reported seeing about 20 individual sterna from Manatees hunted in the Bijagos Archipelago by a single Senegalese fisherman who seasonally fished there. In 1997, the government signed an agreement with IUCN to develop a National Plan for Conservation of the West African Manatee in Guinea-Bissau, and some training and survey work started, but the work stopped when the war started in 1998 and has never resumed (Silva and Arajo 2001). The major source of mortality before the war was accidental capture in fishing nets; they were not extensively hunted. Silva and Arajo (2001) reported 209 Manatees killed between 1990-1998, approximately 23 per year. More recently, Manatees have been advertised by a private company for export on the internet, and two were exported to the Toba Aquarium in Japan in 1996 (Asano and Sakamoto 1997, Kataoka et al. 2000).
Little information is available on the Manatee in Guinea. The country has extensive suitable habitat (Powell 1996), but no systematic studies have been carried out (Barnett and Prangley 1997). Manatees occur in the Soumba, Konkour and Fatala estuaries, Sangareyah Bay, Rio Komponi, Rio Nunez and the border area of the Guinean southern coast, notably in the Benty estuary (Thophile et al. 2008, Camara 2011). In the eastern side of Guinea, Manatees are reported in the Niger, Tinkisso and Gambia Rivers and at Haute Niger National Park (Thophile et al. 2008). In Boffa and Bok, Manatees are more easily observed during the rainy season, in channels when they are feeding (Thophile et al. 2008). Manatees are reported in the estuary at Dubrka, and a new research project will begin studying them there (O. Camara pers. comm.). In 2009 a Manatee carcass was recovered in Kanfarand (C. Kpoghomou pers. comm.), and two Manatee calves were rescued from fishermens nets and released in Dubrka and Benty in 2011 and 2013 respectively (Camara 2011, O. Camara pers. comm.). According to CITES records, six live Manatees were exported from Guinea to China in 2008.
The presence of Manatees has long been recorded throughout Sierra Leone. Early work confirmed its occurrence throughout the coastal areas of Bonthe and Pujehun districts and the Sierra Leone River estuary as well as in all rivers (Lowes 1970, Robinson 1971). Reeves et al. (1988) reported their presence widely in Sierra Leone, including the Great Scarcies, Little Scarcies, Sierra Leone, Sherbro, Wanje and Sewa river systems and Lake Mape. Manatees migrate between the Malem, Shenge, and Wange Rivers and probably move upstream near Teboh, and their presence is confirmed at Yeluba Island (Reeves et al. 1988). The southern side of the coastal area (Shenge to Sulima) is believed to contain the most important numbers of Manatees, but there are no data on population numbers (Siaffa and Jalloh 2008). Recent work by Siaffa and Jalloh (2006) reported that their occurrence in many wetlands is seasonal, with high numbers seen up rivers during the rainy season when the water level is high. They are also frequently reported devastating rice fields during the rainy season, and with the rise of the water level there is also an increase in accidental captures in fishing nets(Siaffa and Jalloh 2008). As of the late 1980s the species was still widely distributed in the country, but the catches at that time were thought to be unsustainable. The Manatees are trapped, netted and harpooned (Powell 1996). Although the Manatee is considered sacred in northern Sierra Leone, and therefore not directly hunted, when incidentally caught it is still eaten (Siaffa and Jalloh 2008). Hunting is most prevalent in the wetlands of southern Sierra Leone, where Manatee meat and oil are relatively common household food items, selling for approximately 2,500-3,000 Leone (less than 70 cents in USD) per half kg piece (Siaffa and Jalloh 2006). Heavy hunting activity is also reported in river mouths, particularly in mangrove areas (van der Winden and Siaka 2005).
Manatees have been recorded from the St. Paul River, Mesurado River, the lower Moro, St. John River, as well as the Cestos and Sankwen Rivers and in the Piso Lake region (Powell 1996). Information collected from fishermen and riparian communities in 2006 indicated that Manatees occur in the Cavalla River estuary in the southeast (Wiles and Makor 2008). The main threats to Manatees in Liberia are reported as accidental entanglement in fishing nets, direct hunting, boat collision (propeller injuries), and habitat destruction (Wiles and Makor 2008). No information is available on status and there are no current manatee studies in Liberia.
Cte d'Ivoire (Ivory Coast)
Information about Manatee distribution and relative abundance in Cte dIvoire was collected for the first time between 1978 and 1983 by the German Technical Assistance Mission (MATA), which surveyed 107 sites and estimated that the number of Manatees living in Cte dIvoire was well below 850 individuals (Roth and Waitkuwait 1986). Akoi (2004) reported that the Manatee occurs along the entire coastal region of Cte dIvoire, as well as in all main rivers and their estuaries, and almost all lagoons. According to findings of surveys and the movements of individuals monitored by VHF radio telemetry from 1986-1988 and 2000-2002 (Powell 1996, Akoi 2004), six main areas of occurrence were identified: the Aby-Tendo-Ehy lagoon complex with the estuaries of River Tanoh and River Bia; the Ebri lagoon complex with the mouth of River Como; the west Ebri lagoon complex with the mouth of River Agneby; the Tagba-Makey-Tadio-Niouzoumou lagoon complex with the mouths of River Bandama and tributaries of G and Boubo; Ngni lagoon with the mouths of River Bolo and Niouniourou; the mouths of the Sassandra, San Pedro and Cavally Rivers. Groups of 10 to 20 individuals were observed several times in the Ngni lagoon in Fresco in the month of August (Akoi 2004). Human development is believed to be the reason why Manatees have completely disappeared from waters around Abidjan (Akoi 2004). A programme of research and education led by K. Akoi from 1986 until his death in 2009 was the longest running Manatee research programme in Africa to date. The population was tentatively estimated at 750800 Manatees in five to six small, isolated populations (Akoi 2004). Illegal hunting is still a problem, as is habitat destruction including development and dams (the Kossou dam in the Bandama River and the Buyo dam in the Sassandra River). Hunting is illegal, but continues, with traps, harpoons, hook lines, baited hooks and nets all used (Roth and Waitkuwait 1986, Nicole et al. 1994, Powell 1996, Akoi 2004). There was some success in educating potential hunters and in enforcing the hunting ban in some areas (Akoi 2000), but unfortunately all programmes ended after the death of Akoi in 2009, and there are currently no research or conservation activities taking place. According to CITES records, four live Manatees were exported to Taiwan in 2004. At least two of these were sent to Farglory Ocean Park; one of these died in 2010 and the second is still in captivity at the park (T. Mignucci pers. comm.).
The African Manatee occurs in coastal and inland waterways in Ghana, particularly in the Afram arm of Lake Volta, and in the rivers Dayi, Asukawkaw, Obusum, Sene, Digya and Oti (Ofori-Danson 1995). Manatees occur in Abi, Tano and Ehy lagoons in the southwest of Ghana (Roth and Waitkuwait 1986). They are also found in the River Tano, the lagoons and swamps associated with the lower Volta and in Lake Volta (formed by construction of the Akosombo dam). There are reports of sightings in the tributaries of the river Tordzie, such as Lolo, Altra, and Hortor in the southern area of Tongu. However, there is no report of its presence in the White or Black Volta Rivers. Ofori-Danson and Agbogah (1995) concluded that the confluence of Oti could define the upper limit of the distribution area of the Manatee in Ghana. The African Manatee has become very elusive in Lake Volta under stress from declining water levels and hunting (P. Ofori-Dansen pers. comm.). In addition, environmental degradation in the Lake Volta is on the increase. The situation continues to worsen as the human population of Ghana continues to grow, urbanization and tourist development increase and human activities become diversified (P. Ofori-Dansen pers. comm.). As a result, there is growing concern to educate the populace and also to facilitate the Ghana Wildlife Division charged with the responsibility of managing the countrys terrestrial and aquatic wildlife resources to take action. Legal protection has been established for Manatees in Ghana, and the Wildlife Division prohibits trade and hunting of Manatees. However, the enforcement of wildlife laws protecting the Manatee is frustrated by a lack of resources, manpower and limited awareness of existing regulations (P. Ofori-Dansen pers. comm.). In 2007, the Earthwatch Institute supported a project entitled Enhancing conservation of the West African Manatee in Ghana. During this project, no Manatees were encountered, suggesting that the stock could be too depleted to support further removal and there is urgent need for enforcement and conservation measures (P. Ofori-Dansen pers. comm.).
Manatees were previously reported in Kpessi, Agbodrafo, Abatkop (near Anho), and in Lake Togo at Ekpui, Togoville, Kta, Akoda and Kounou, but this is no longer the case (Segniagbeto et al. 2008). The Manatee is observed in Lake Togo with its tributaries the Zio and Haho, and in the Mono River. According to the findings of surveys undertaken in 2006 among riparian communities and field observations, the Manatee population on Lake Togo is important (Segniagbeto et al. 2008). There are two concentration areas in Lake Togo: one in the south of the lake, and the other at the junction between the lake and the River Haho. The existence of these two concentration areas would justify the number of skulls observed in the villages of Amdhov and Dekpo, which are the closest to those areas. It seems that the confluence between Lake Togo and the river Haho generally supports more Manatees than in the Lake Togo-Zio area (Segniagbeto et al. 2008). All interviewed fishermen exploiting Lake Togo have confirmed this. The population in the Mono River is very sparse according to fishermen, but there is a reported area of population concentration at Adam. The northern distribution limit of the species in the Mono is in the village of Agom-Glozou. Young Manatees are regularly observed by fishermen, and in Lake Togo, mating herds are observed especially when individuals are sighted in groups during the flood period of the Haho and Zio Rivers. It is necessary to design a significant map of former and current Manatee areas to establish an efficient conservation status, and to determine any impacts of the Mono Rivers Nangbeto hydroelectric dam on Manatees (Segniagbeto et al. 2008).In March 2015, a collaboration between the Togolese NGO Alliance Nationale des Consumateurs et de lEnvironment and the Togo Ministry of Security resulted in the arrest of a Manatee hunter in Dkpo in possession of more than 20 skulls and 40 vertebrae of Manatees.
In Benin, the Manatee had been thought to be extinct (Perrin 2001). However, this is not the case (Powell 1996, Tchibozo 2002, Dossou-Bodjrnou 2003, Dossou-Bodjrnou et al. 2006). The Manatee is sporadically distributed across the whole country (Ichola and Tchibozo 2008). It occurs in coastal areas, including estuaries and coastal lagoons, in the great rivers in both brackish and fresh water, and in freshwater lakes, with reported sightings from both northern and southern wetlands (Affomasse 1999, ABE 1999, Guedegbe 2000). In the Niger valley, Manatees may be encountered in areas of medium depth at the confluences of the Mkrou-Niger and the Alibori-Niger, and in the branches of Bello Tounga and Kompa Gourou. Manatees are found in Bonou, Wbossou, Skodji Gom, Ouinhi, Agonli-Hougbo (Kpoto) and Lac Sl (Adjakpa 2002, Tchibozo 2002). They are frequently seen stranded in seasonal lakes off the Oueme River during the dry season (Tchibozo 2002, Dossou-Bodjrnou et al. 2006, Chabi-Yaour 2012). In the Mono River, Manatees are seen migrating during high water periods, and are reportedly concentrated near the village of Hv and near the beaches of Avlo in the Boucle du Roy in Benin (Dossou-Bodjrnou 2003, Ichola and Tchibozo 2008). Manatees are hunted throughout Benin for food and traditional medicines (Ichola and Tchibozo 2008).
The Manatee is distributed throughout Nigeria including the Niger, Benue and Cross Rivers and their tributaries, as well as coastally (Sykes 1974, Powell 1996, Awobamise 2008). Manatees are present in Lake Kainji above the dam and this population is isolated from other Manatees both upriver (by the Kandjadji dam under construction in northwestern Niger), and downriver by the Kainji dam (constructed in 1968). Manatees occur along the length of the Benue River and most of its tributaries, including the Gongola, Taraba, Donga Rivers, the Pie River as far as Yankari, the Katsena Ala River and the Deb River, which drains Lake Pandam, an important dry season refuge (Powell 1996, Oboto 2002, Sykes 2010). The Manatee is believed to be depleted throughout Nigeria due to hunting and incidental capture during fishing operations, including the use of explosives in rivers (Powell 1996, Oboto 2002, E. Eniang pers. comm.). It is hunted for its meat, oil and for organs used in traditional medicine (Oboto 2002, Awobamise 2008). There is no effective enforcement of protection laws. Another substantial threat is habitat destruction due to development and pollution of the Niger Delta by oil development. A fisherman of Sapele district reported that Manatees of different ages and sizes were found dead and floating after the Jesse petroleum pipeline fire incident (Oboto 2002). Several new studies of Manatees in Nigeria have begun in the last five years, including work by University of Uyo in the Cross River region (E. Eniang et al. unpublished data), a project training former Manatee hunters in aquaculture as an alternative livelihood in Lekki Lagoon near Lagos (B. Dunsin unpublished data), and a new study of Manatees in Lake Pandam (R. Gbegbaje pers. comm.).
In Cameroon, Manatees occur throughout the coastal region, from the extensive mangroves and estuarine waters of the Ndian Delta and Bakassi area in the west to the Wouri and Mungo Rivers and the Cameroon Estuary, and south to the Sanaga River and the lower sections of the Nyong and Ntem Rivers (Nishiwaki 1982, Powell 1996, Noupa 2008). Manatees are frequently observed in the Douala-Edea Wildlife Reserve, the lower Sanaga River, and Lake Tissongo (Takoukam 2012). Manatees occur in the Sanaga River as far as Edea, where there is a dam and rapids, and in Lake Ossa (connected to the Sanaga), which has been documented as an important year round sanctuary (Powell 1996, Takoukam 2012, Mayaka et al. 2015). Inland, Manatees are found in the upper Cross River, especially around the Munaya-Cross confluence, and they also occur in northern Cameroon in the Benue River, from the Faro River and the Mayo-Kebbi to Lakes Trn and Lr in Chad (Powell 1996). Manatees cannot descend the Benue into Cameroon south of the Lagdo dam. Although Grigione (1996) reported that illegal hunting was very limited in Cameroon, more recent reports have shown otherwise: Manatees are regularly hunted in the lower Sanaga region and Lake Ossa, and Manatee meat can be found in markets in Douala on a regular basis (Powell 1996, Takoukam 2012). Along the coast, incidental capture in fishing nets and habitat destruction are also problems (Takoukam et al. 2013). According to CITES records, two live Manatees were exported from Cameroon to South Korea in 2008, and four more were exported to China in 2010. A new marine mammal stranding network set up in 2013 that covers coastal Cameroon, the Wouri and lower Sanaga Rivers and Lake Ossa documented 157 Manatee sightings (comprising 349 individuals) and thirteen incidentally caught Manatees between February and October 2013 (Takoukam et al. 2013).
The African Manatee is present in the coastal areas of Equatorial Guinea on mainland Africa, but is absent from Bioko and Annobn islands (Dodman 2008c). The main areas of occurrence are in the Muni and Cogo estuaries, and it most likely occurs in the Rio Woro estuary and the Rio Ecucu near Bata, where one was captured in 1988 (Rpublica de Guinea Ecuatorial 2005). Machado (1998) considered that the Rio Muni area contained prime habitat for the Manatee. Bolobo (2001) reported that the Rio Muni supported an appreciable population of Manatees. They probably occur in the lower reaches of the Mitml River on the mainland (Powell 1996). In the southernmost part of Equatorial Guinea, Manatees are occasionally sighted in Corisco Bay and around Corisco Island where sparse seagrass beds of Halodule wrightii have been documented (Keith and Collins 2007). There are no current Manatee research or conservation activities in Equatorial Guinea.
Gabon may have one of the highest densities of Manatees remaining in Africa (Powell 1996, Keith et al. 2006, Keith and Collins 2007, Keith Diagne 2011, Keith Diagne 2014). Reports of opportunistic sightings are common in the Ngowe and Ndogo Lagoons, particularly at the northern ends and in associated rivers (Keith et al. 2006, Keith and Collins 2007). During the rainy season Manatees are also frequently sighted in seasonally flooded lakes off the Rembo Bongo north of Ndogo Lagoon, including Kivoro, Gore, Longa Longa, Mafoume, Mouaga, and Marimossi Lakes (L. Keith Diagne unpublished data). Louembet (2008) reported high Manatee seasonal use of the Abanga River and associated lakes, as well as hunting of 133 Manatees in this region from 2005-2008. Manatees are reported, but are sighted much less frequently in Mondah and Corisco Bays, the Libreville Estuary and Komo River, the lakes of the Ogooue region, and Banio and Fernan Vaz Lagoons (Mbina 2001, Endamne 2007, Keith Diagne 2011, L. Keith Diagne unpublished data). Bycatch occurs in gillnets and directed hunting is reported, primarily in the lower Ogooue River and associated tributaries and lakes in the region of Lambarn, as well as occasionally in Ndogo Lagoon (Louembet 2008, Mvele and Arrowood 2013, L. Keith Diagne unpublished data, G. Minton pers. comm.).New mitochondrial genetics results for Gabon identified eight control region haplotypes, the highest number found for the species in any African country to date, indicating high genetic diversity (Keith Diagne 2014). Additionally, seven of eight haplotypes only occurred in a single water body, which may indicate strong local adaptation and low genetic mixing (Keith Diagne 2014). Manatees traveling between major lagoons and rivers in Gabon would need to move between these sites using the ocean, which has very strong currents and a narrow continental shelf. African Manatees are rarely documented in the Atlantic Ocean off Gabon, and with abundant food resources in rivers and lagoons, generally do not need to move between freshwater habitats. Similar geophysical barriers have been hypothesized to impede movements of West Indian manatees (Hunter et al. 2012).
Republic of the Congo
Manatees occur throughout coastal rivers, lakes and lagoons of the Republic of the Congo, and have been documented in Conkouati National Park, and the Kouilou and Lom Rivers (Akoi 1994, Kaya 2005, Bal and Brheret 2007, Kaya 2008). Surveys of Conkouati Lagoon and adjacent rivers and lakes indicated that Manatees are seen primarily in the lakes and at the mouth of Conkouati Lagoon near sandbanks (Akoi 1994, Dodman et al. 2006, L. Keith Diagne unpublished data). Surveys of the Kouilou River region conducted by the NGO Renatura (Bal and Brheret 2007) confirmed Manatee presence in Lakes Nanga, Ndinga, and Katina, as well as the following tributaries of the Kouilou: the Mboukou Massi, the Loundji, and the Midounvo rivers. However, the same study concluded that Manatees were not present in Lake Youbi and presence could not be confirmed in Lake Koubambi (Bal and Brheret 2007). In the Lom River, Manatees are reported primarily in the lower river and its estuarine areas, and fishermen also reported that Manatees occur in Lake Kayo, south of the Lom, in the dry season (Kaya 2005).
The Democratic Republic of the Congo
Hatt (1934), Allen (1942) and Powell (1996) reported that Manatees were common in the lower reaches of the Congo River. Manatees are regularly reported along the coast at Parc Marin des Mangroves and a hunted Manatee was observed at Boma in 2013 (S. Mbungu pers. comm.) Status is unknown, but given the frequency of sightings reported across the river on the Angola side (Collins et al. 2011) it is possible there is a sizeable population in the lower Congo River. Powell (1996) reported that a local name for the species exists in the upper reaches of the Congo River so it may occur there as well, although other reports for this region (Allen 1942, Dodman 2008b, J. Hart pers. comm.) do not believe Manatees exist above the rapids, and today it would have to be an extremely isolated subpopulation since it is unlikely Manatees can traverse the extreme gorges in the river west of Kinshasa.
Manatees have been reported along the coast from the Congo River in the north, to the Longa River in central Angola, but little information is available on abundance or status (Powell 1996, Dodman 2008a, Collins et al. 2011). Morais (2006) found Manatees in the Longa River, extending their southernmost range to that river from the Cuanza. Manatees have been documented the length of the Cuanza River and its tributaries and lagoons from the river mouth to Cambambe dam, which, prior to construction of the dam, was characterized by steep rapids that also presented a natural barrier (Morais 2006). The Manatees distribution also extends up the Lucala River (a main tributary on the north bank) for at least 30 km upstream from the Cuanza River. Key sites of the river basin include areas at and around Cauigia Lagoon, Cabemba Lagoon, the Ta Lagoons, Quissungo Lagoon and a small extension of the Ngolome Lagoon, as well as in the Caua River and in the Massangano region (Morais 2006). Based upon boat and interview surveys conducted from 2007-2009 in the lower Congo River from the mouth to 40 km upriver, as well as numerous tributaries on the Angola side of the river, Manatees are commonly sighted in this region (Collins et al. 2011). One Manatee was sighted by the survey team in the Nzadi Caca tributary of the Congo River in 2007 and it stayed near the boat for 1.5 hours, surfacing approximately every 8-10 minutes (Collins et al. 2011). Only one local hunter was identified in all interviews of villages from the mouth to 40 km upriver, and he was interviewed by L. Keith Diagne before he passed away in 2008. The hunter estimated he had killed approximately three Manatees a week (using harpoons and nets) for the past 30 years (L. Keith Diagne unpublished data). Manatees are hunted on the Cuanza River, Manatee meat has been seen for sale in the capital of Luanda, and a fisherman from a village at a lagoon on the Bengo River reported 77 Manatees killed during 1998 (Ron 1998, Morais 2006). Xavier (2011) documented a Manatee hunted by net capture in Lake Camba.
Manatees are found throughout the entire Niger River system of Mali and in the Bani River but may have been reduced by hunting (Powell 1996, Berthe 2011). The Makala dam at Segou (constructed in 1945), another planned dam at Taoussa, as well as additional dams in Guinea and Niger, have chopped Malis Niger River Manatee populations into smaller habitat areas, and is of great concern for the conservation of the species in that country. There are no estimates of population numbers. In 2010 a Manatee carcass was recovered in Koulikoro (Timbo 2010), constituting the furthest inland record for the species, although there are reports of sightings further west from Bamako (Kienta et al. 2008). Manatees are frequently sighted in the Bani River near Djenn and Mopti, and have been documented regularly drinking from a freshwater spring near the village of Sokon (Berthe 2011). Manatees are also frequently reported in Lake Debo and the surrounding area in the inland Niger delta (Kienta 1982, Kombo and Toko 1991, Kienta et al. 2008). In western Mali Manatees occur in the Senegal River up to the Felou dam at Kayes, which prevents them from moving further upriver (L. Keith Diagne unpublished data).
Poche (1973) declared the Manatee extinct in Nigers Park W, but this is not the case. A study by Ciofolo and Sadou (1996) found Manatees throughout the Niger River in Niger. In the northern Ayorou region (extending from the border with Mali to Tounga Faire), Manatees were sighted throughout the year and a large number of skulls collected by hunters indicated heavy poaching (Ciofolo and Sadou 1996). In the region of Park W, Manatees were sighted in the main channel of the Niger River and a female was accidentally captured in 2002 (Ciofolo and Sadou 1996, Issa 2008). In 2010 a new Manatee study was initiated in this region (Boubacar 2010). In the southern Niger Boumba-Gaya section of the river, Manatees have been observed during low water periods, which may indicate migration elsewhere during other times of the year (Ciofolo and Sadou 1996). A male Manatee was captured in this area in 2004 but only survived in captivity for two weeks (Issa 2008). In June 2012, several Manatees were observed together in the Niger River in downtown Niamey near a major bridge (a possible mating herd). One female from this group was harpooned and killed by a hunter; the carcass was confiscated and biological samples were collected (Boubacar 2012). Manatees are heavily hunted throughout Niger for meat and organs (which are believed to have healing powers), and although the species is fully protected under national laws, there is little if any enforcement (Issa 2008).
Manatees were once abundant in the Chad basin including the Chari, Bamingui, Bahr-Kieta, and Logone Rivers, but became rare by 1924 and are now believed to be extinct in this region (Hatt 1934, Powell 1996, Salkind 1998). Lake Chad is greatly reduced in size and desertification is a big problem there. Today Manatees occur only in Lakes Lre and Trne, as well as the Mayo-Kebbi River which feeds the lakes from the west (Idriss 2008). In a survey in 1995, Manatees were found to be less abundant than formerly, but not uncommon in both lakes (Salkind 1998). Hunting continued on the rivers and lakes, despite enforcement efforts. The animals were sought mainly for their oil, which is shipped with dried meat to Cameroon (Perrin 2001). As of 2011 it has been reported that there are few Manatees left in Lakes Lre and Trne, and that the local people have formed militias to protect the Manatees from Nigerian poachers who come across the border to kill them at night (J. Hart and A. Wachoum pers. comms.).
Manatees inhabit all of the nations that surround Burkina Faso (Mali, Cte d'Ivoire, Ghana, Togo, Benin and Niger), but have never been reported within this country. They are present in Volta Lake above the dam (see Ghana above). However, Perrin (2001) could find no mention of its occurrence in the upper tributaries of the Volta (White Volta, Red Volta and Black Volta) or in the Mekrou River, which forms the boundary between Burkina Faso and Togo/Benin and drains the wetlands of the Parc National de l'Arly. Pending directed surveys, its occurrence there must be considered possible (Perrin 2001).
In Cte dIvoire, Powell (1996) sighted Manatees on a daily basis, but found numerous large box traps situated around the rivers and lagoons from the Ghana border to Fresco. The 4 x 1 m traps are constructed of wooden poles stuck in the bottom and a door weighted with a large rock. Powell (1996) built two of these box traps for catching Manatees to radio tag; he caught five Manatees in two traps over four days. These traps are also used in Nigeria and Ghana (B. Dunsin unpublished data, M. Yelibora pers. comm.). Manatees are also caught in special nets with large mesh used specifically for Manatees. In Guinea-Bissau, Silva and Arajo (2001) reported 209 deaths from 19901998; of these, 72% died in fishing gear, 13% were hunted, 4% stranded at low tide and 11% the cause of death was undetermined.
Incidental bycatch in fishing gear is also a major threat in all African countries, and even when captured alive, most incidentally caught Manatees are not released, but are killed. Takoukam et al. (2012) reported 13 Manatees incidentally caught and killed in fishing gear in nine months in coastal Cameroon. Cadenat (1957) recorded the deaths of five Manatees around Joal, Senegal in nets used for catching sharks. Manatees are frequently caught in monofilament nets that are now commonly used in all African countries. Manatees are occasionally killed in fishing trawls. In Cte dIvoire, stationary funnel nets are placed across the inlets of major rivers to catch shrimp swept past on tidal currents. These are strong nets that have a wide mouth that faces upstream and then narrows down to a small bag on the cod end. The tidal currents where they are usually set are often strong and several of these nets can block the entire channel. Between 1986 and 1988, three Manatees were killed in the vicinity of Grand Lahou by drowning in these nets, including one radio tagged Manatee (Powell 1996). Akoi (1992) described how Manatees in Cte dIvoire are sometimes caught in fishing weirs made of sticks. These weirs are common in Cte dIvoire and in many other areas in Africa.
In some locales there have also been reports of killings of large numbers of Manatees over a short period of time, such as 17 individuals killed in the Afram Arm of Lake Volta (Ofori-Danson and Agbogah 1995), 77 Manatees in the Cuanza River Angola in 1998 (Morais 2006), and 133 Manatees killed over three years in the Abanga River in Gabon (Louembet 2008). Johnson (1937) reported that as many as 12 Manatees a day were caught in a 100 mile (161 km) stretch of the Gambia River. Powell (1985) estimated around two Manatees a year were taken between 1978-1983 from this same area though this change cannot be attributed to less hunting pressure or reduced Manatee numbers (or both). If these large scale hunting operations are not curbed, it is entirely possible that the species will become extinct in certain places.
Due to poverty, remoteness and lack of enforcement, Manatees are taken for food and traditional medicinal products throughout their range (Powell 1996). Manatee meat is openly sold in local markets. In Cameroon, Manatee meat was sold along the roadside near Douala and could easily be spotted from a passing car. Manatee meat was seen on three out of five visits during a three month period (J. Powell pers. obs.). In the market in Lambarene, Gabon, Manatee meat was documented nine times between March 2012 and March 2013, as well as additional reports of Manatee being served in local restaurants during the same time period (Mvele and Arrowood 2013a). Manatee meat and oil is reported to move illegally in trade from Chad to Nigeria and Cameroon (Powell 1996, A. Wachoum pers. comm.). In Mali, Nigeria, and Chad, Manatee oil is more prized than the meat. The oil is used for its reputed medicinal properties to cure rheumatism and to condition the skin and hair (Kienta 1982, Reeves et al. 1988). Oil from the head is used to treat ear infections. In Mali and along the Benue River, certain cuts of the meat are considered to have particular useful properties. For example, the parts of the penis are used to cure impotency in men, and the skin can be made into whips (Kienta 1982, Powell 1996). In Sierra Leone, villagers consume all parts of the Manatee carcass except for the heavy ribs (Reeves et al. 1988). The meat is shared among villagers and any remains are sold by the trapper. The bones are used to make handles for walking sticks or spinning-tops used in a local game called cii. Little historical data exists for comparison to the present to know if decreases in catch rates are occurring over time.
Recent threats include loss of habitat due to damming of rivers, cutting of mangroves for firewood and destruction of wetlands for agricultural development. Coastal development all along the western side of the African continent is decreasing Manatee habitat.
In recent times hydroelectric and agricultural dams have also isolated Manatee populations in many major rivers, including in Lake Volta, Ghana (Akosombo Dam, constructed in 1965), the Niger River (Kainji Dam in Nigeria, constructed in 1968, and the Markala Dam in Mali, completed in 1945), and the Senegal River (Diama Dam, constructed in 1983 and the Kayes Dam in Mali). Since 2008, the Niger River Basin Authority has authorized the construction of three additional multi-purpose dams: at Fomi in Guinea, Taoussa in Mali, and Kandjadji in Niger (Diarra 2011). An additional dam has also been authorized at Kayes Mali on the Senegal River. All of these are likely to further restrict Manatee habitat in these countries and lead to genetic isolation of populations. At the Kanji dam on the Niger River, Nigeria and at the Akosombo dam on the Volta River, Ghana, Manatees have been known to be killed in the turbines and intake of the hydro-electric generator (Powell 1996). In Nigeria, for example, Isahaya (pers. comm.) reported seeing as many as six Manatee carcasses at one time below the Kainji dam. An agricultural dam constructed in 2008 at Navel, Senegal on a seasonal tributary of the Senegal River killed five Manatees within the first four years after it was built: three due to drowning against dam grates and two due to entrapment behind the dam. Seven other live Manatees were rescued from behind the same dam and released back into the Senegal River (Oceanium Dakar and L. Keith Diagne unpublished data).
In countries including Benin, Senegal, and Angola, Manatees can become trapped in small lakes as rivers and flooded areas dry up in the dry season (Dossou-Bodjrnou et al. 2006, Morais 2006, Oceanium Dakar unpublished data). In some cases, such as during a severe drought in Lake Guiers in the 1970s, Manatees died due to stranding (Dupuy and Maigret 1978). In other cases, becoming trapped in these smaller bodies of water makes Manatees more vulnerable to hunting.
Coastal development near Abidjan, Cte dIvoire resulted in loss of habitat and increased human disturbance contributing to the disappearance of Manatees in the area. Although still rare in Africa, increases in motorized boats and large vessel traffic in some of the rivers and lagoons may also pose a threat from collisions with watercraft, the highest known cause of death in Florida and Belizean Manatee populations. A pregnant female Manatee was struck and killed by a boat at a natural gas port at the mouth of the Congo River in Angola in 2007, and residents of nearby villages report a large decrease in Manatee sightings in the area since construction on the large facility began (L. Keith Diagne unpublished data).
National and international trade in live Manatees exists. In Nigeria and Mali Manatees have been captured for exhibit in local zoos. These Manatees usually die after a short time in captivity because their caretakers have not been properly trained and/or did not provide them enough food. Between 2000 2010, CITES records show that a total of 28 live Manatees were exported from four African countries (Cameroon, Guinea, Guinea-Bissau, and Cte dIvoire) to aquaria in Asia (Japan, Korea, China, and Taiwan). Wild caught Manatees from Guinea-Bissau are offered for sale on the internet (River Zoo Farms). However, with the up-listing of the species to CITES Appendix I in March 2013, international trade is no longer legal.
The species is believed to be in decline throughout much of its range, but without accurate baseline information it is impossible to know how to conserve these Manatees, and conservation is also unlikely without capacity building. A lack of long-term, committed funding, as well as the difficulty of accessing the extremely remote regions where African Manatees live, murky water habitat throughout their range, and the animals elusiveness, have severely limited studies. This species is only likely to be conserved through a network of grassroots, localized efforts by African researchers dedicated to long-term conservation and education efforts in their countries, and through increased funding to conservation activities.
Cte dIvoire had one of the most important Manatee conservation programs from 19892009 (Akoi 1992, Akoi 1994, Akoi 2000, Akoi 2004) but unfortunately it ended with the death of its leader, K. Akoi. Akois staff were left with no support when funding was withdrawn after his death. This was a hard lesson that too often Manatee programs in Africa are dependent on the work of individuals. More people need to be trained and efforts need to be integrated into broader conservation programs so that Manatee conservation initiatives do not end if one person is no longer able to continue the work.
Many new African Manatee conservation initiatives have begun since 2008. From 20072009 the Earthwatch Institute (UK) funded annual training workshops for African biologists interested to begin Manatee research and conservation activities. The workshops were held at Lake Volta, Ghana and were led by P. Ofori-Danson, C. Self-Sullivan, and L. Keith Diagne. Over three years 33 participants from 17 African countries were trained, and equally importantly, a spirit of collaboration was born. When Earthwatch funding ended, L. Keith Diagne continued the training workshops in other countries, and built an African Manatee researcher network to increase and sustain communication between researchers in different countries, increase data collection, conservation activities, and educational awareness programs. The long-term strategy is to create a sustainable and cohesive network of African researchers who will determine population sizes and status of African Manatees in a majority of the 21 range countries, as well as develop and implement management plans for conservation of the species. The network continues to try to identify collaborators from all 21 countries. As of 2015, L. Keith Diagne has conducted five additional training workshops in Gabon, Mali, The Gambia, and Guinea-Bissau for 80 African biologists from 19 countries. In May 2010, Wetlands International Africa (WIA) conducted a training workshop in Senegal with a modular course given by P. Ofori-Danson to17 local experts and wildlife managers from six African countries. General recommendations for this initiative were presented afterwards (Morales-Vela and Castelblanco-Martinez 2011). In 2013 and 2014, A. Kamla Takoukam also conducted two training workshops in Cameroon for 30 biologists. Year-round Manatee research now occurs in nine countries.
Current African Manatee research and conservation projects include:
- Senegal Manatee conservation at Tocc Tocc Community Natural Reserve, a protected area at Lake Guiers, which was named Senegals fifth Ramsar site in early March 2014 (L. Keith Diagne and Diagne unpublished data), a countrywide status and distribution study by L. Keith Diagne, and a national marine mammal stranding network implemented in 2015 (Mullie, Diagne, Keith Diagne, and Djiba, unpublished data);
- Guinea cultural practices and Manatee conservation in the Forcariah estuaries (O. Camara Masters thesis research);
- Ghana Dr. P. Ofori-Dansens long-term study of Manatees in Lake Volta;
- Mali in the Bani River and inland Niger delta, Soumaila Berthe is building a local Manatee monitoring network and determining Manatee important use areas through habitat assessments and sightings. This project is also conducting extensive educational outreach programmes in the region;
- Nigeria conservation of the African Manatee through community based aquaculture development in Ise Community, Lagos is training former Manatee hunters in aquaculture as an alternative livelihood (B. Dunsin unpublished data), Bio-ecology of West African Manatees in the Badagry and Yewa Lagoons of southwestern Nigeria (U. Ejimadu unpublished data), threats, occurrence and distribution of the West African Manatee in the Niger Delta region of Nigeria: what anthropogenic factors affect their population and what prospects exist for their conservation? (E. Eniang L. Luiselli, F. Petrozi, E. Egwali and A. Nchor unpublished data), habitat quality and hydrobiological factors influencing the occurrence of Manatees in the Lower Qua Iboe and Eniong Rivers (E. Egwali doctoral research), ecology and conservation of West African Manatee in Eniong Creek, implications for sustainable conservation (O. Nkameyin Masters research);
- Niger biology and distribution of Manatees in Parc W (B. Boubacar doctoral research);
- Cameroon assessing the distribution, bycatch and strandings of Manatees on the Cameroon coast and at Douala-Edea Wildlife Reserve, and Manatee research training for biologists and university students (A. Takoukam doctoral research), habitat use and seasonal availability of African Manatee in Lake Ossa Wildlife Reserve, Littoral Region of Cameroon (R. Ngafack Masters thesis research);
- Gabon countrywide Manatee status and distribution (Keith Diagne), Manatee surveys and habitat use of Ndogo Lagoon (C. Nkollo Masters thesis research), Manatee bushmeat surveys and educational outreach campaign of the Ogooue River and Lakes region (Mvele and Arrowood 2013b);
- Angola Manatee use of the Dande River and associated lakes (M. Xavier);
- Range-wide phylogenetics, feeding ecology and age determination studies of the African Manatee (L. Keith Diagne).
List of protected areas in western Africa where Trichechus senegalensis is known to occur:
- Cameroon Campo Ma'an National Park, Douala-Edea Wildlife Reserve, Lake Ossa Wildlife Reserve, Korup National Park;
- The Democratic Republic of the Congo Parc Marin des Mangroves;
- Republic of the Congo Parc National de Conkouati;
- Gabon Akanda National Park, Loango National Park, Mayumba National Park, Pongara National Park;
- Gambia Baboon Island National Park, Bao Bolong Wetland Reserve, Niumi National Park, Kiang West National Park, Tanbi Wetlands Complex;
- Ghana Digya National Park;
- Guinea National Park of Upper Niger;
- Guinea-Bissau Cantanhez Forest National Park, Orango Islands National Park, Joao Vieira Poilao Islands Marine National Park;
- Ivory Coast Azagny National Park, Iles Eotiles National Park;
- Mauritania Diawling National Park;
- Nigeria Kainji Lake National Park, Pandam Wildlife Park, Jos Wildlife Park, Obudu Game Reserve;
- Niger Le Parc du W;
- Senegal Parc National de Basse Casamance, Parc National du Delta du Saloum, Parc National des Oiseaux de Djoudj, Reserve Naturelle Communitaire de Tocc Tocc, Parc National du Niokolo-Koba, and Sanctuaire Ornithologique de la Pointe de Kalissaye.
Relevance to Humans and Ecosystems
Villagers in Sierra Leone consider Trichechus senegalensis a major pest of rice crops. Fishermen believe these animals are responsible for removing fish from nets, but this is unconfirmed (Reeves et. al. 1988).
Villagers in Sierra Leone and Nigeria hunt Trichechus senegalensis for their meat (Reeves et. al. 1988). They have developed elaborate means of trapping the animals which they eventually kill with harpoons or guns (Sikes 1974 and Robinson 1971). In contrast to this, villagers in Cameroon have a different perception of Trichechus senegalensis. They do not like the taste of the meat and they believe that Trichechus senegalensis are fierce animals that become violent when attacked. Nigerian fishermen are often responsible for the poaching of Trichechus senegalensis in Cameroon (Grigione 1996). It has also been reported that the skin of Trichechus senegalensis has medicinal and therapeutic properties (Reeeves et. al. 1988).
The African manatee (Trichechus senegalensis) is a species of manatee and is the least studied of the four species of Sirenians. Photos of African manatees are very rare; although very little is known about this species, scientists think they are similar to the West Indian manatees. They are found in coastal marine and estuarine habitats and in fresh water river systems along the west coast of Africa from the Senegal River south to the Kwanza River in Angola, including areas in Gambia, Liberia, Guinea-Bissau, Guinea, Sierra Leone, Côte d'Ivoire, Ghana, Mali, Nigeria, Cameroon, Chad, Gabon, Republic of the Congo, and Democratic Republic of the Congo. Although crocodiles and sharks occasionally kill manatees in Africa, their only significant threats are from humankind, such as poaching, habitat loss, and other environmental impacts.
They live as far upstream the Niger River as S gou, Mali. Although rare, they occasionally get stranded as the river dries up at the end of rainy season and are cooked for a meal. The name in Songhai, the local language, is "ayyu". A landlocked colony of manatees also lives in Lake Lere in southwestern Chad near the Cameroonian border something of an anomaly given that the lake is hundreds of miles inland and not connected to the sea in any way.
Manatees roam the Urasi River in the Okija-Ihiala-Oguta area between Anambra and Imo States of Nigeria. These animals are normally in the area between July through November when the Urazi River is heavily flooded. It is believed that they roam from the Oguta Lake in Oguta, Imo State downstream to the River Niger in Onitsha, Anambra State upstream. Sometimes, they run aground and are killed for meat by local people. They are also hunted for the meat, although the Nigerian Government is believed to have outlawed killing the animals. Locally, in Okija, manatees are called "Emei.'
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