• The abundance, biomass and composition of pelagic ciliates in East African lakes of different salinity and trophy

      Yasindi, A. W.; Taylor, W. D. (2006)
      Planktonic ciliates were studied in 17 tropical East African lakes of different salinity and trophic status. Oligotrichs (e.g., Strombidium, Strobilidium and Halteria) and scuticociliates (e.g., Cyclidium, Pleuronema, Cristigera), dominated the ciliate communities. Conductivity and trophic status were the most important environmental variables influencing the distribution of ciliate species in East African lakes. Herbivorous oligotrichs were important in oligotrophic and mesotrophic lakes, as they are in temperate and subtropical lakes, but their importance decreased with increasing chlorophyll a concentration and conductivity. On the other hand, the importance of scuticociliates (primarily bacterivores) increased with increasing chlorophyll a and conductivity. Mean ciliate abundance ranged from 2 to 1,220 ciliates.mL-1 while the biomass range was from 1.9 to 1, 900 ~kg C.L-1 respectively from oligotrophic to eutrophic lakes. Abundance and biomass had positive relationships with phytoplankton biomass. The ciliate abundance and biomass were higher than those reported in temperate (Quebec) and subtropical (Florida) lakes of similar trophic status. However, regression models predicting abundance and biomass of ciliates from chlorophyll suggest that temperate (Quebec), subtropical (Florida) and tropical (East Africa) lakes have similar ciliate abundance and biomass per unit chlorophyll except some saline tropical lakes which have very high abundance and biomass of ciliates relative to chlorophyll.
    • Accessing Funding for Conservation and Research Work in Kenya: presented at a workshop on 'Writing Funding Proposals and Communcating Results', National Museums of Kenya 10-12 May 2004.

      Ruhiu, J.M. (CDTF, Biodiversity Conservation Programme (BCP)Kenya, 2004)
      Developing countries have limited financial resources to support conservation and research and even where finances are incorporated in government budgets, these are inadequate. Kenya has a diverse assemblage of natural resources requiring huge financial resources. Although wildlife tourism generates up to US$ 27 million annually and a third of foreign exchange earnings, contributing up to 10% to formal employment and 5% to GDP, little of this fund is ploughed back either to support conservation or to benefit communities which support conservation. Most of the generated income is repatriated to developed nations and up to 55% of generated resources is believed to remain in developed nations where booking and marketing are carried out. Conservation has both public and private costs. Management costs are estimated at US$ 25 million and opportunity cost of conserving wildlife habitats in terms of alternative land uses forgone estimated at US$200 million per year. Wildlife related damage is estimated at 35-45 of total production in wildlife areas. As conservation sites do not generate enough financial returns to cover huge costs involved, there is a huge gap between the generated financial returns and conservation costs. The worst hit is the forest sector where it is estimated that Kshs. 100 is allocated towards conservation of one hectare of indigenous forests. In order to finance forest conservation, indigenous forest should be made financially self supporting where income generated from the forest should finance conservation directly. Recurrent cost to conservation is largely from the government while development support is mainly from donors. Based on the financial resources to wildlife and forest sectors, it is apparent that conservation is not self supporting as huge financial resources are required. Low financial allocation to conservation is attributed to; varied interests – corporate, government, individuals, foundations, trusts; weak policy for conservation fund raising; failure to match up allocation to conservation with other sectors and inability of conservation initiatives to sustain themselves. 2 Funding to conservation is from the central government through royalties & fees; multilateral and bilateral donors and private sector funding; Charities; Trusts and Foundations; United Nations Agencies; Multinationals, Trans-nationals and Corporate World; Private sector funding and endowments. Funding to conservation and research can be enhanced through; improving existing sources; developing new ones; encouraging conservation investment and soliciting private donations. Fundraising can be through; funs, walks and runs advertisements; social corporate responsibilities; exhibitions & trade fairs; donations and membership. Project sustainability is paramount if it will offer both conservation and community benefits. Initiatives of ensuring sustainability include; enterprise related activities; endowment fund, through collection of conservation fee; royalties; village conservation fund; institutionalization of user fees and moderate taxation for conservation support – policy shift; information and community sensitivity on conservation and capacity development as an element of ensuring conservation support and awareness.
    • Advocacy on Mangroves Restoration: Tanzania Case Study

      Rweyemamu, Chrysostom (East Africa Wildlife Society, 1998)
      The mangrove forests' ecological importance is largely responsible for the existence of communities living around the forests. Mangroves are not only the habitat of the unique fauna and flora which make them important in the eyes of conservationists, but also serve as feeding grounds and nursery for marine fisheries; stabilize the coastline by preventing coast erosion; prevent siltation of the economically important coral reefs by trapping sediments; build land through accumulation of silt and the production of detritus; preserve the purity of the water by absorbing pollutants from coastal upland sources and serve as windbreakers for the agricultural hinterland.
    • Allometric Models for Estimating Standing Volume of a Replanted Mangrove Plantation in Kenya

      Lang'at, J.K.S.; Bosire, J.O.; Karachi, M.; Kairo, J.G.; Muchiri, M.N.; Kamondo, B.; Ochieng, D.; Tuwei, P.; Wanjiku, J. (Kenya Forestry Research InstituteNairobi, Kenya, 2009-06)
      Allometric equations were developed and used to estimate standing volume of a l2-year old Rhizophora mucronata Lam. plantation at Gazi bay, Kenya. Twenty two plots, each measuring 10 x 10m2, were established in six belt transects laid perpendicular to the waterline. Fifty trees of diameters varying from 2.5 to 11.5 cm were selected within the plots and harvested. Merchantable volume of the harvested trees was calculated using the Smalian's formula while the nonmerchantable volume was derived from weight-volume conversation ratios. The total stand volume was estimated as 100.4 m3 ha-1 with an annual increment of 8.4 m3 ha-1yr-1 ; giving a biomass expansion factor (BEF) of 2.04 ± 0.74 t m-3. A local volume table based on stem diameter and height was constructed, which allows quick estimation of tree volume.
    • Application of Thermal Remote Sensing for Geothermal Mapping, Lake Naivasha, Kenya.

      Pastor, Michael S. (International Geothermal AssociationBochum, Germany, 2010)
      Remote sensing of the earth‘s surface records energy reflected or radiated by an object at different wavelengths of the electromagnetic spectrum. The wavelength region of 3-14 μm is called thermal infrared region. The Landsat Thematic Mapper (TM) band 6 usually referred to as the thermal band operates in the wavelength of 10.4-12.5 μm with ground resolution of 120 meters. The tone of a thermal image expresses surface radiant temperature. Radiation emitted by the ground objects is measured for temperature estimates. Lake Naivasha, a freshwater lake, and the geothermal areas surrounding it lie on the central part of the Kenya Rift Valley (KRV). Its water is being used not only for domestic water supply and agriculture but also for the exploitation of geothermal energy. Surface manifestations, in the form of hot springs, fumaroles, solfatara, altered grounds and other volcanic-related features that are common in geothermal areas are present in Lake Naivasha and are indications of the presence of geothermal resource at depth. A qualitative and quantitative interpretation of the thermal image south of Lake Naivasha shows that thermal manifestations and structural features in general show a relation with high heat flow. Geothermal manifestations including the wells show up on the image as scattered points with high temperature pixels with values ranging from 20-40 oC. They appear to be restricted on the west side of the main thermal divide in a NE-SW direction especially along the Olkaria Fault Zone that cuts through the geothermal area.
    • Aquatic Resource Management in the Western Indian Ocean African Region.

      Ruwa, R.K.; Annala, J.H. (International Center for Living Aquatic Resources Management (ICLARM)Makati City, Philippines, 1997)
      In multidisciplinary studies of aquatic systems, water must be considered as a resource as well as one with biological and physical resources. Prominent for communities living around aquatic systems are their fisheries resources. These resources play an important role in providing them with employment; they also play an important part in their nutrition.
    • Assessment of Infiltration Using a Mini Rainfall Simulator in the River Njoro Watershed.

      Okelo, M.O.; Onyando, J.O.; Shivoga, W.; Miller, S.N. (International Lake Environment Committee FoundationShiga, Japan, 2008)
      Hydrological changes in many watersheds worldwide have been attributed to land use change. In the River Njoro watershed, vast forested land has been replaced by other land uses including agriculture and grazing. This has led to decrease in infiltration in many parts of the watershed. The study was aimed at establishing the effects of land use• change on infiltration in the watershed. The study was done on runoff plots, which was used to assess infiltration in the watershed. There was a randomized block design with fi\c land use treatments and three replicates (sites) per treatment. The site plots were mapped using Global positioning System (GIS) and plotted in a Geographical Information System (GIS) environment. A rainfall simulator having dimensions of 0.4m by 0.25m was used to simulate rainfall on plot size of 0.1 m2. In every site rainfall was applied at an average rate of 10mm/h on three plots using a rainfall simulator. Infiltration, the difference between applied rainfall and runoff, generated from three sites in each land use was measured. The soil properties including bulk density, texture, organic matter content and pH were measured in every site. The highest infiltration was on indigenous forest and decreased in the order of plantation forest, deforested area, agricultural and grazing land. The mean infiltration rates for each land use were 43.5, 37, 26.2, 25.4 and 20.2 mm/hr. Statistical analysis (P< 0.05) showed that their were significant differences in infiltration between forested areas and all other land use areas. The land under forested cover registered high infiltration whereas areas of the watershed characterized by intensive interference of land cover and soil surface conditions experienced low infiltration. It is evident from the results that afforestation needs to be encouraged in the watershed.
    • Biodiversity and sustainable management of a tropical wetland lake ecosystem: A case study of Lake Kanyaboli, Kenya

      Rasowo, J.O.; Abila, R.; Manyala, J.; Ministry of Water and Irrigation, Nairobi (Kenya) (2006)
      Lake Kanyaboli and the surrounding Yala swamp wetland has been recognized as an important biodiversity hotspot. Recent population genetic and phylogenetic studies confirm the evolutionary importance of Lake Kanyaboli (Kenya) in preserving the cichlid fish fauna of Lake Victoria. The adjoining Yala swamp harbours the endangered swamp antelope Sitatunga (Tragecephalus spekii) and several papyrus endemic birds. The lake and adjoining swamp play a critical role in the livelihood of the local communities who heavily depend on the wetland resources. Current ongoing large scale land use changes within the swamp threaten the ecological integrity and functioning of this highly dynamic wetland ecosystem. It is therefore imperative that proper management and conservation measures be put in place to protect Lake Kanyaboli and associated Yala swamp wetland. This paper presents a review of the biodiversity of Lake Kanyaboli and the associated wetland and the threats the lake ecosystem faces. Polycultural ‘finger ponds’ aquaculture, tourism and papyrus based industries as well as an all stakeholders driven management plan are suggested as a step towards achieving sustainable management, utilization and conservation of the Lake Kanyaboli ecosystem.
    • Biological control of water hyacinth on Lake Victoria, Kenya.

      Ochiel, G.R.S.; Mailu, A.M.; Gitonga, W.; Njoka, S.W. (1998)
      The Kenya Agricultural Research Institute (KARI) imported 12 800 curculionid weevils (Neochetina spp.) from Benin, Uganda, South Africa and Australia for biological control of water hyacinth between 1993 and1998. In 1996, KARI’s rearing and quarantine facility at the National Agricultural Research Centre, Muguga, provided initial “breeding stock” to another rearing facility at the National Fibre Research Centre, Kibos, near Lake Victoria. To date, 36 500 weevils and 42 000 weevil eggs have been produced from Kibos. About 2000 weevils were produced each month from plants grown in plastic basins, galvanized corrugated iron sheet tanks and a polypropylene rearing pool. Between January 1997 and August 1998, KARI released 36 250 Neochetina weevils at 27 sites and redistributed 7 800 weevils along the Kenyan Lake Victoria shoreline. Visual observations and a pre- and post release sampling protocol have been used to monitor the establishment, spread and impact of Neochetina weevils on water hyacinth. Weevils are established at 5 sites and have spread as far as 50 km away from release sites. Preliminary quantitative data from 5 sites indicate a reduction in leaf length, lamina area and fresh weight at several sites and general increases in larval mining, feeding scars and adult weevil density.
    • The biology and distribution of Haplochromis spp in the Nyanza Gulf prior to the total invasion of the Gulf of Nile perch, Lates niloticus (L)

      Mwalo, O.M. (ICIPE SCIENCE, 1994)
      The work reported was conducted during the watershed period of 1976 when Nile perch (Lates niloticus) started to replace Haplochromis spp. in dominance in the Nyanza Gulf of Lake Victoria. Seventy four "groups" of Haplochromis species flock obtained from a stock assessment survey of that year were used in the study. The length of fish examined varied between 57 and 237 mm total length, and between 1 and 182 g wet weight, with means of 101.05 mm and 18.53 g respectively. Frequency distribution curves for both sexes were unimodal with a maximum between 70 and 130 mm. The t-test showed that the two sexes came from the same population. Clutch size per fish (mean weight 25.3 g and mean total length 106.7 mm) was 78 eggs. The minimum size at maturity was 89 mm for males and 93 mm for females. Living condition coefficient was highest at developing stages. Sex ratio calculations per "group" were found illogical as most "groups" were exclusively monosexual. Most of the Haplochromine "groups" fed on phytoplankton (41%), others on molluscs (21%), fish material (12%), insect larvae (9%), adult insects (8%), macrophytic detritus including sand grains (7%) and zooplankton (4%). Feeding competition was lowest among the grazers on the abundant phytoplankton and highest among the adult aquatic insect eaters. Nematode parasitic infestation was common among female fish. Haplochromis spp. were collected in all the hauls and usually in greatest concentrations from a depth of 4 m through to 49 m. Over 80% of the 74 "groups" were represented in the 4-9 m depth interval, 59% in the 10-19 m depth interval, 68% in the 20-29 m depth interval, 30% in the 30-49 m depth interval and only about 10% of the groups were represented in the deepest 50-69 m depth interval.
    • The Co-existence between Oreochromis niloticus and Lates niloticus in Lake Victoria (Kenya Sector).

      Ogari, J.; Bwathondi, P.O.J. (Kenya Marine and Fisheries Research InstituteMombasa, Kenya, 1990)
      The present study was undertaken to try and find out why Lates niloticus and Oreochromis niloticus have managed to co-exist in Lake Victoria (Kenya sector). The study is considered to be of tremendous scientific value not only because lates has been accused of preying on the cichlid stocks in L.Victoria but also for considering suitable management approaches to maintain viable fishery resources on long-term basis. The results presented are preliminary and the final detailed results will be presented later when the survey will have been accomplished.
    • Coastal Aquaculture Potential of East Africa

      Bwathondi, P.O.; Institute of Marine Sciences (1981)
      Studies on the aquaculture potential of East African coast has been given. Due to the large expanse of mangrove areas in the region, it has been suggested that the culture of penaeid prawns, particularly Penaeus indicus (H. Milne Edwards), P. monodon (Fabricius), P.semisulcatus (De Haan) and Metapenaeus monoceros (Fabricius) be attempted in the mangrove areas and creeks. Such rearing experiments should be run concurrently with experiments involving the breeding of the prawns in the laboratory. Experiments carried out on the rearing of mollusks show that the region does not support any appreciable growth of oysters, particularly the commercial species. The dominant genera in the region are Ostrea and Crassostrea. The former genus has a slow growth rate and little meat yield. Experiments are underway to determine the aquaculture potential of mussels. Fish culture, particularly the culture of rabbitfish Siganus spp. has a promising future in the region. Rearing experiments carried out at the Institute of Marine Sciences, University of Dar es Salaam, Zanzibar, have indicated that the fish can be cultured to maturity size of 23.4 cm total length within about 8-9 months. The growth rate of this fish has also been determined by the author. Other fish which have a promising aquaculture potential in the region are milkfish Chanos spp; and Epinephelus spp. The study of seaweeds of Tanzania has reached an advanced stage. Already researches are underway to open seaweed farms both in Zanzibar and Pemba Islands and along the coast of Tanzania Mainland. One of the most valuable seaweeds which has attracted great attention in the region is Eucheuma spp.
    • Community involvement in fish harvesting around Lake Victoria (Kenya)

      Omwega, R.N.; Ministry of Water and Irrigation, Nairobi (Kenya) (2006)
      Benefits accruing to fishing communities have not marched increases in fish yields. This has affected the disadvantaged groups especially women who rely on processing and marketing fish for their livelihood. The aim of this study was to asses the extent of community involvement in fish harvesting activities, the benefits accruing, perceptions towards fisheries regulations and their constraints in regard to threats and risks they face in Lake Victoria. Sampling was conducted on 25 landing beaches between August and November 2000 and a total of 229 fishers interviewed. Data was obtained using a structured survey questionnaire on fish production and personal interviews. Seventy two percent felt that their occupation was not sustainable due to low prices of fish, 70% of fishers joined the fishery for period between 1 to 10 years, 81% operated on full-time basis, while 19% operated on parttime. During the Government of Kenya retrenchment exercise, there was a short-term influx into the fishery. In a good week, a fisher could earn an average of Kshs.7, 750. In a bad week one could earn approximately Kshs.1, 822. Fishers sampled were familiar with fisheries laws and regulations applied in the management of Lake Victoria fisheries 90%. The results show most fishers have no alternative occupation apart from fishing with men dominating in the harvesting sector while women only owned fishing gears and equipments. Although majority of fishers worked on full-time basis, they have limited or no influence on the levels of benefits they receive from the activity and this can be supported by the unemployment caused by the fish processing factories that fish directly by providing efficient gears and boats to fishermen.
    • A comparative study on the feeding habits of Oreochromis niloticus (Linnaeus) in Nyanza Gulf Lake Victoria and sewage fish ponds

      Getabu, A. (ICIPE SCIENCE, 1994)
      Gut content analysis of Oreochromis niloticus from the Nyanza Gulf, Lake Victoria showed that the bulk of the food items ingested constituted bottom deposits and blue green algae. Among the live food items ingested, blue green algae (Cyanophyceae) constituted 53.6%, the diatoms (Bacillariophyaceae) 19.7%, aquatic invertebrates (mainly Copepoda, Cladocera, and Rotifera) 12.9%, desmids (Desmidaceae) 7.7% and lastly the green algae (Chlorophyceae) 6.2%. The most preferred food items were: Spirulina laxisma and Nitzschia accicularis. The least preferred food items were: Lyngbya circumcreta, Microcystis aeruginosa and Pediastrum simplex. The quantity of food eaten by O. niloticus to satiation ranged from 0.016-4.5% body weight. The high growth performance index of the fish is attributed to the food on which it feeds on. The results obtained from the Gulf are compared with those of ealier work done on the food of the species in sewage fish ponds which discharge their effluent into the lake.
    • The composition and structure of the plankton community in the Tudor creek, Mombasa, Kenya.

      Okemwa, E. (Swedish Agency for Research Cooperation with Developing Countries (SAREC)Stockholm, Sweden, 1993)
      This study was undertaken with a view to describing the species composition and the community structure of copepods in the Tudor Creek, Mombasa, Kenya. The first quantative study of the pelagic zooplankton community of the Tudor Creek was undertaken from December 1984 to December 1987. Between December and March 1985 a Bongo plankton net of. 335 ~km mesh size was used from the vessel ”R.V. Maumba”. From April 1985 to December 1987 a conical plankton net was used from a small canoe equipped with an outboord engine. The net, with a mesh aperture size of 335 ~km, a length of 1 m, and 45 cm in diameter at the mouth, was fitted with aflow meterat the mouth. Surface plankton samples were taken from September 1985 to August 1986 using a small canoe at each of five permanent stations during day-and night-time, at one neap and one spring tide each month. Thereafter only day-time neap and spring tide samples were taken from September 1986 to December 1987 at the five stations. 24hours cycle sampling was occasionally done at stations 1and 5 simultaneously. Results from the study shows that zooplankton are rich and abundant. Over 51 taXil were recorded. Close to74 % of the zooplankton comprised copepods of which the most important were calanoids followed by cyclopoids, poecilostomatoids, harpacticoids and monstrilloids. The most commonly encountered calanoid species were Centropages orsinii, Acrocalanus longicornis, Clausocalanus tarrani, Temora turbinata, Paracalanus aculeatis, P. simplex, Canthocalanus pauper, Undinula vulgaris, Acartia danae, Euchaeta marina and Eucalanus spp. The most common cyclopoid and harpacticoid species encountered were Corycaeus specious, Oncaea venusta, Copilia mirabilis, Sapphirina laetens. Oithona plumifera, O. setigera, O. simplex and Microsetella rosea, Euterpina acutifrons. Macrosetella sracilis respectively. Only occasionally did copepods of the order Monstrilloida appear in the samples. Some 99 copepod species, representing 41 genera and 30 families, have been identified. Amongst these,17 species were dominant but 6 of these including; Calanus darwini. Labidocera laevidentata, Paracalanus crassirostris, P.indicus. P.tropicus and Sapphirina lactens, were recorded for the first time in the Western Indian Ocean off the Kenyan coast.
    • Conflict management in Mombasa Marine National Park and Reserve, Kenya: a spatial multicriteria approach.

      Tuda, A.; Rodwell, L.; Stevens, T.; Edwards, Alasdair; Hooper, Tara (University of Newcastle and Marine Education TrustNewcastle-upon-Tyne, 2007)
      Multiple uses of the marine and coastal environment inevitably lead to spatial conflicts. This paper examines a methodology designed to inform management decisions on conflict management by identifying conflict hotspots and determining optimal feasible use patterns. The methodology involves three stages: multicriteria decision analysis (MCDA), geographical information systems (GIS) and integer goal programming (IGP). We use the case study of Mombasa Marine National Park and Reserve to illustrate how the methodology can be implemented. We make suggestions of further work that is needed in order to validate and improve the methodology developed here.
    • Conservation efforts of the East African Whale Shark Trust in Kenya.

      Bassen, V.; Irvine, T.R.; Keesing, J.K. (CSIRO Marine and Atmospheric ResearchAustralia, 2007)
      While it is known that the highly migratory nature of whale sharks results in the world’s largest fish being found in the waters of Kenya, minimal research has been conducted into their distribution and abundance along the Kenyan coast. The whale shark is listed on Appendix II of the Convention on International Trade in Endangered Species (CITES) and the Convention on Migratory Species (CMS), however the species is not protected by law in Kenya and whale sharks fishing remains unchecked. The East African Whale Shark Trust (EAWST) was established in 2005; it is a non-profit organisation concerned with the conservation and research of the whale shark. This paper describes what is presently known about whale sharks in Kenya and the goals of the EAWST.
    • The Cowries of the East African Coast (Kenya, Tanganyika, Zanzibar and Pemba).

      Verdcourt, B. (1954)
      All the species known to occur on our coasts are included in this present paper. Rarities have been included since they are needed for the museum collections.
    • Degradation of the riparian wetlands in the Lake Victoria basin - Yala swamp case study.

      Thenya, Thuita; Wassmann, Reiner; Verchot, Louis; Mungai, David (2006)
      Land degradation is as a result of broad range of scales and factors, which include biophysical, climatic, demographic and socio-economic. The aim of this paper was to provide an analysis of wetland utilisation, ecosystem degradation and their effect on the Lake Victoria (Kenya) ecosystem. This involved analysis of socioeconomic and remote sensed data. The main sources of wetland degradation in the Lake Victoria basin were identified as (1) farming activities, (2) grazing and macrophyte harvesting and (3) coupled with catchment degradation-deforestation. These factors were closely related to the demographic dynamics and unsustainable land utilisation practices. Socio-economic data provided valuable insight on the pattern of wetland utilisation and possible sources of degradation pressure. For example, there is high dependence of the local indigenous livelihood directly on the swamp for subsistence needs including farming, grazing and income generation. Farming is the most important wetland utilisation activity, which takes 95% of the households wetland land holding mainly for subsistence use. In addition, there has been progressive degradation of the catchment area through deforestation, overgrazing and low furrow period. This results in high sediments transport and other pollutants to the lake ecosystem due to the removal of buffering effect of the macrophytes in the swamp especially along river Nzoia systems. Remote sensing data indicated progressive opening of the swamp especially in the high population and more accessible northern side of the swamp. In conclusion, the unsustainable use of natural resources in the basin has had significant negative effect on the Lake ecosystem including water pollution siltation and increase of floating biomass.
    • Distribution and association of Tilapine unit stocks in the Lake Victoria catchment (Kenya)

      Jembe, B.T.; Boera, P.N.; Okeyo Owuor, J.B.; Ministry of Water and Irrigation, Nairobi (Kenya) (2006)
      The Lake Victoria Catchment (Kenya) harbours six species of tilapia. Two species Oreochromis variabilis (L) and Oreochromis esculentus (L) are endemic while four species Oreochromis niloticus, Oreochromis leucostictus, Tilapia zillii(Gervais) and Tilapia rendalli(Gervais) were variously introduced in 1950s and early 1960s. The existence of six tilapia species in the same geographical range has had significant ecological and economical implications. The study investigated the ecological impacts by determining species diversity, distribution, association (allopatric, sympatric and parapatric) and habitat preferences for the six-tilapia species. Shannon-wiener index was used to determine diversity, while species distribution was evaluated on the basis of 39 habitats (dams and satellite lakes) within the catchment. Species associations were determined using Cole’s Cab index. The Shannon Weiner function values of 2.44-2.7 indicate relatively high species diversity in 15% of 33 habitats where Tilapia were resident. Cole’s Cab indices showed significant relationships in O. esculentus X O. variabilis, O.leucostictus X O. esculentus, O. niloticus X O. variabilis and O. niloticus X O. leucostictus at P < 0.05. Habitat preference for the six species is provided.