Department of Environmental Studies

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Environmental assessment of the East African Rift Valley lakes
(Aquatic Sciences, 2003) Odada, Eric, O.; Olago, Daniel, O.; Bugenyi, Fred; Kulindwa, Kassim; Karimumuryango, Jerome; West, Kelly; Ntiba, Micheni; Wandiga, Shem; Aloo-Obudho, Peninah; Achola, Pius
An assessment of the East African Rift Valley lakes was initiated by the United Nations Environment Programme (UNEP) with funding from Global Environment Facility as part of the Global International Waters Assessment (GIWA). The purpose of GIWA was to produce globally comparable assessments and examine stresses on international waters: marine, coastal and fresh; surface and groundwaters. The assessment of the East African Rift Valley lakes was undertaken from the perspective of water quality and quantity, associated biodiversity and habitats, their use by society and societal causes of the regionally identified issues and problems. Assuming intrinsic values of aquatic ecosystems, the assessment of social perspective focused on human use of water and considered the incremental costs of measures to encourage sustainable development. The assessment identified the major concerns facing the East African Rift Valley lakes. By and large, pollution and unsustainable exploitation of fisheries and other living resources emerged as critical concerns attributable to human activities. East Africa has a very high concentration of humans and economic activities. Pollution is from uncontrolled discharge of wastes directly into the lakes. Unsustainable exploitation of fisheries and other living resources is caused by over-fishing, destructive fishing practices, and introduction of non-native species that affect the composition of the native communities, resulting sometimes in the collapse of certain species and dominance by resilient ones. Loss of biodiversity also was identified as a major concern; and the issues of excessive by-catch and discards are also relevant. Trawling using undersized mesh-nets for target species and indiscriminate fishing gear or poison is serious, in most cases resulting in indiscriminate catches, including juvenile fish. Given the transboundary nature of the issues identified in this assessment, appropriate multilateral policy and institutional arrangements need to be established in East Africa to address the main concerns of these large lakes. Riparian countries must pay attention to the regional management of these transboundary water bodies, and appropriate planning of human population sizes and their settlement, land-use and waste disposal to control pollution. Although East African lakes contribute relatively little emission of greenhouse gases, there is a need to reduce the rate of deforestation and even restore cleared areas since forests serve as sinks of greenhouse gases towards mitigating adverse climatic changes.
Biological diversity of the Yala Swamp lakes, with special emphasis on fish species composition, in relation to changes in the Lake Victoria Basin (Kenya): threats and conservation measures
(Biodiversity & Conservation, 2003-05) Aloo-Obudho, Peninah
During the second half of the last century, the Lake Victoria ecosystem has undergone drastic ecological changes. Most notable has been the decline in the populations of many endemic cichlid fishes. The lake has lost nearly 200 haplochromines and one tilapiine, Oreochromis esculentus. The above changes have been attributed to effects of species stocking and, in particular, from predation pressure by the introduced Nile perch, Lates niloticus. Other factors that have led to the decline of the endemic species include intensive non-selective fishing, extreme changes in the drainage basin, increased eutrophication, and the invasion of the lake by the water hyacinth, Eichhornia crassipes. However, the remnants of some species that had disappeared from Lake Victoria occur abundantly in the Yala Swamp lakes (Kanyaboli, Sare and Namboyo). This paper discusses the biodiversity of the swamp and the three lakes and gives suggestions for their conservation.
Metazoan Parasites of Some Commercially Important Fish along the Kenyan Coast
(WIOMSA, 2004) Aloo-Obudho, Peninah; Anam, R.O.; Mwangi, J.N.
The parasitic fauna of some commercial fish species along the Kenyan coast was investigated at four localities between August 2001 and March 2002. The study was carried out to establish the extent of parasitisation of different fish species and quantify the relationship between the parasites and their fish hosts. Fish samples were collected once a month from four landing beaches. Sixteen fish species were examined out of which only eight were infested with ecto-and endo parasites. The infested fish species included: the rabbitfish (Siganus sutor), the mackerels (Selar crumenophthalmus, Scomberomorus commerson and Rastrelliger kanarguta), parrot fish (Leptoscarus vagiensis), sardine (Sardinella gibbosa), tuna (Thunnus sp.) and needle fish (Hemiramphus far). Of the eight species, Si. sutor was most infested with parasites while Sardinella and Leptoscarus were primarily infested with ectoparasites (isopods). Intensity of infestation increased with age (size), especially in Si. sutor, where very young fish had a low infestation rate, while adults were heavily infested (P < 0.01). No significant differences were observed in the intensity of infestation between sexes in Si. sutor (P > 0.05).
Lake Baringo: Addressing threatened biodiversity and livelihoods
(Lakes & Reservoirs: Research & Management, 2006-12) Odada, Eric, O.; Onyando, Japheth, O.; Aloo-Obudho, Peninah
Lake Baringo is a shallow, internal drainage, freshwater lake located in the Kenyan Rift Valley. The lake is an important source of water for humans and livestock, as well as a significant income source for local communities through activities such as tourism, biodiversity conservation, and fish sold in local markets. The lake has been subject to overfishing, as well as to greatly enhanced sedimentation as a result of land use changes in the drainage basin. This paper provides an analysis of the conditions prevailing at Lake Baringo, and examines in detail the management response to the problems facing the lake. The roles of the many and varied institutions in the lake basin's management are discussed, and an analysis of internationally funded projects designed to ameliorate the situation is provided.
The risk of pathogenic intestinal parasite infections in Kisii Municipality, Kenya
(BMC Public Health, 2008-07) Nyarango, Robert, M.; Aloo-Obudho, Peninah; Kabiru, Ephantus, W.; Nyanchongi, Benson, O.
Background: Intestinal parasitic infections are among the most common infections worldwide. Various epidemiological studies indicate that the prevalence of intestinal parasites is high especially in developing countries, although in many of these, the environmental risk factors have not been clearly elucidated. The objective of this study was to determine the risk of pathogenic intestinal parasites infections in Kisii Municipality. Methods: Random sampling was used in the selection of the study samples. Stool parasitological profiles of food handlers were done by direct smear and formalin-ethyl acetate sedimentation method. Both vegetable and meat samples were examined for the presence of intestinal parasites. The storage and meat handling practices of the various butcheries were observed. Results: Types of samples examined for occurrence of intestinal parasites includes, a total of 84 vegetable, 440 meat and 168 stool samples. Fifty five (65.5%) vegetable, 334 (75.9%) meat and 69 (41.1%) of the stool samples were found positive for intestinal parasites indicating a high overall risk (66.18%) for intestinal parasite infections. Of the parasites detected, the most common parasites infesting the foodstuffs and infecting the food handlers were Ascaris lumbricoides and Entamoeba histolytica. Parasites were significantly less likely to be present on meat that was refrigerated during display than meat that was displayed at ambient temperature. Conclusion: There is a high risk of infection with intestinal parasites in the sampled Municipal markets. About half of the food handlers surveyed (41.1 %) at the Municipal Hospital had one or more parasitic infections. Furthermore, meat (65.5%) and vegetables (75.9%) sold at the Municipal market were found to be contaminated with parasites hence the inhabitants requires a need for education on food safety, good distribution practices and improvement on sanitary conditions.
Comparative performance of invasive alien Eichhornia crassipes and native Ludwigia stolonifera under non-limiting nutrient conditions in Lake Naivasha, Kenya
(Hydrobiologia, 2010-09) Njambuya, Josephine; Triest, Ludwig
The ability of Ludwigia stolonifera to thrive in the presence of Eichhornia crassipes was investigated in Lake Naivasha, Kenya. L. stolonifera (indigenous) and E. crassipes (invasive alien) were grown in outdoor experimental boxes in monocultures and mixtures under non-limiting nutrient conditions. An additive series design with eight combinations of planting densities and four replicates was used. Competitive interactions between the two species were determined by assessing the final total biomass and above–below-ground biomass allocation after 98 days of growth. Biomass accumulation and allocation were significantly affected by competition in relation to species, with L. stolonifera accumulating more biomass than E. crassipes. ANOVA analysis indicated that there was no significant difference in Relative Growth Rate (RGR) and root/shoot ratio between monocultures and mixtures with E. crassipes. However, significant differences in RGRs were observed between monocultures and mixtures of L. stolonifera. Multiple regressions on species RGRs revealed that increasing initial biomass of a conspecific neighbour resulted to a greater reduction in species RGR in relation to increasing initial biomass of a hetero-specific neighbour. Thus, a stronger intrathan inter-specific competition coupled with the significantly higher RGR of L. stolonifera relative to that of E. crassipes enabled L. stolonifera to outperform E. crassipes
Financing provision of environmental services in Mt. Elgon region for the protection of watersheds
(VDM Dr Muller Gmbh and co, 2011-01) Sumukwo, Joel; Kipkoech, Anderson K.; Roba, Adano W.; Mwima, Polycarp M.; Omondi, Humhprey; Kairu, Gerald; Osano, Odipo; Matere, Stella
This study examined direct payments for environmental services (PES) as a program for supporting the conservation of forest resources and services where environmental conservation is financed on the basis of beneficiaries pay for the environmental services (ES) they enjoy, while contributors to these services are compensated for their provision. The objective of the study was to determine distribution of forest resource benefits among different interest groups and assess impacts of PES on conservation efforts and total value of forest utilisation in terms of improved environmental service provision. Data was obtained through administration of a questionnaire to 376 households in two districts adjacent to Mt. Elgon forest. Data was analyzed using SPSS. Results show that conservation impacts are indirect and realized with considerable efforts only in the long term. In order to implement PES schemes, there is need to build a strong legal and institutional frameworks that consider land use decisions affecting both forest and non-forest land cover. Payments for restoration and conservation would help landowners have long term obligation to accelerate forest re-growth and gains in water services. The other benefit of PES includes lessening competition between conservation efforts and improving local community welfare.
Competition between Lemna minuta and Lemna minor at different nutrient concentrations
(Plant Biology and Nature Management (APNA) Elsevier, 2011-02) Njambuya, Josephine; Stiers, Iris; Triest, Ludwig
We investigated the differential responses of invasive alien Lemna minuta and native Lemna minor to nutrient loading as well as the mechanism of competition between the species. The role of nutrients, species identity, species influence in determining the outcome of competition between the species was estimated using the Relative Growth Rate Difference (RGRD) model. The two species differed in their response to nutrient loading. The native L. minor responded indifferently to nutrient loading. The species Relative Growth Rate (RGR) was 0.10 d−1, 0.11 d−1 and 0.09 d−1 in high,medium and low nutrients, respectively. On the other hand, the invasive L. minuta responded opportunistically to high nutrient availability and had an RGR of 0.13 d−1, 0.10 d−1 and 0.08 d−1 in high, medium and low nutrients, respectively. As a result, the invasive species was dominant in high nutrient availability but lost to the native species at low nutrient availability. The invader formed approximately 60% and less than 50% of the stand final total dry biomass in high and low nutrient availability, respectively. Species RGR were reduced by both intra- and interspecific competition but intraspecific effects were stronger than interspecific effects. On the overall, the species significantly differed in their constant RGR. These differences in RGR between the species (species identity) and the differential response to nutrient loading were the main determinant of change in final biomass composition of these species in mixture. Species influence (competition) only had a small influence on the outcome of competition between the species. The observed species response to nutrient loading could be targeted in management of the invasive species. Lowering nutrients can be proposed to reduce the impact of the invasive L. minuta.
Dryland Farming and Food Security in Kenya: Challenges and Research Priorities
(Elixir, 2011-06) Mwenzwa, Ezekiel
Agriculture is the backbone of Kenya and employs the highest proportion of the population, accounts for approximately a quarter of the country’s Gross Domestic Product (GDP) and close to two-thirds of total exports, hence its importance in poverty alleviation. Despite the importance of the sector, about four-fifths of the country’s land area is arid and semi-arid (ASAL), making rain fed agriculture largely enviable. As such, livestock and dry land farming are elevated to the highest among livelihood options for resident communities who are largely nomadic pastoralism and agro-pastoralists. While weather patterns are largely responsible for low crop yields and therefore food insecurity, there are other factors that come into play to escalate want in these areas including socio-cultural dynamics and institutional bottlenecks. This paper looks at the challenges of dryland farming in semi-arid areas of Kenya and henceforth points at possible research gaps that need to be bridged to alleviate food insecurity and enhance national development and the achievement of the UN Millennium Development Goal 1 of eradicating extreme poverty and hunger
Competitive abilities of invasive Lagarosiphon major and native Ceratophyllum demersum in monocultures and mixed cultures in relation to experimental sediment dredging
(Aquatic Botany, 2011-06) Steirs, Iris; Njambuya, Josephine; Triest, Ludwig
Competitive abilities of Lagarosiphon major (Ridley) Moss (invasive in Belgium) and native Ceratophyllum demersum L. were assessed experimentally in relation to sediment dredging. We mimicked these conditions by taking undisturbed sediment (‘before dredging’ treatment) and by using restored sediment where the uppermost nutrient rich top layer was removed (‘after dredging’ treatment). Both the species were allowed to grow for seven weeks in monocultures and mixed cultures at different planting densities. Overall, invasive L. major performed better than native C. demersum independent of the characteristics of the growth environment. L. major achieved a higher relative growth rate (RGR) in both treatments based on total length (0.17–0.21 week−1) and weight (0.10–0.19 week−1) compared to C. demersum (length: 0.04–0.07 week−1; weight: 0.03–0.17 week−1). The better performance of L. major was due to a high plasticity under stressful conditions of low free CO2 and high pH. Intraspecific competition and niche partitioning were observed between the two species indicating that species coexistence is favoured instead of competitive exclusion. L. major performed better in the ‘after dredging’ treatment. Consequently, we deduce that sediment dredging will not lead to a decline of the invasive L. major
Faecal Bacterial and Parasitic Contamination of Drinking Water in Eldoret Municipality, Kenya
(2012) Olunga, Maureen Stella
Faecal contamination of water can introduce a variety of pathogens into water ways, including bacteria, viruses, protozoans and parasitic worms. Poor excreta disposal is often associated with lack of adequate water supplies, poor sanitation facilities and low economic status populations. In this study water samples were collected from wells, taps and harvested rain water containers in Kimumu area of Eldoret municipality in Kenya and analyzed using standard bacteriological and parasitological methods. The quality of tap and rain water was found to be acceptable. The presence of Escherichia coli in well water was an obvious indication of faecal contamination. Faecal parasites observed were Entamoeba histolytica, Ascaris lumbricoides, Giardia lamblia, Necator americanus, Ancyclostoma duodenale, Fasiola hepatica, Taenia saginata and Taenia solium. To control infestations with faecal intestinal parasites, provision of treated piped water to all homesteads, consultation of water engineers and/or health inspectors before well construction and creation of public awareness are recommended. Scholars of microbiology and parasitology and parasitologists will find this book resourceful.
Prevalence of intestinal parasitic infections in certified food-handlers working in food establishments in the City of Nairobi, Kenya
(Journal of Biomedical Research, 2012-03) Kamau, Paul; Aloo-Obudho, Peninah; Kabiru, Ephantus; Ombacho, Kepha; Langat, Bernard; Mucheru, Obadiah; Ireri, Laban
Most intestinal parasites are cosmopolitan with the highest prevalence in the tropics and subtopics. Rural-to-urban migration rapidly increases the number of food eating places in towns and their environs. Some of these eating estabishments have poor sanitation and are overcrowded, facilitating disease transmission, especially through food-handling. Our investigations in Nairobi, therefore, were set to determine the presence of intestinal parasites in food-handlers with valid medical certificates. Direct and concentrated stool processing techniques were used. Chisquare test and ANOVA were used for data analysis. The parasites Ascaris lumbricoides, Entamoeba histolytica and Giardia lamblia were observed in certified food-handlers. Significant difference was found in parasite frequency by eating classes and gender (χ2 = 9.49, P = 0.73), (F = 1.495, P = 0.297), but not in parasite occurrence between age brackets (χ2 = 6.99, P = 0.039). The six-month medical certificate validity period may contribute significantly to the presence of intestinal parasites in certified food-handlers.
Pre-Disposing Factors Contributing to the Prevalence of Intestinal Parasitic Infections (IPI) among the HIV/AIDS Patients in Bungoma County, Kenya
(International Journal of Science and Research (IJSR), 2014-12) Wanyama, F.W.; Wanjala, A.M.; Oyoo-Okoth, E.
The role of HIV infection on the pathognomomic of HIV infections is not clearly understood. The aim of the current study was to determine the epidemiology of IPI and predisposing factors among HIV/AIDS patients in Bungoma County Hospital. This study was a cross-sectional study on 240 HIV(+ve) and 60 HIV(-ve) individuals. Stool samples were observed for intestinal parasites. Differences in prevalence and intensity of parasites were analyzed using Pearson Chi-square test. Factors causing observed differences in the prevalence and intensity of the parasites were analyzed using Chi-square test to identify significant factors responsible for observed prevalence. Significantly (χ2 = 23.764, df = 1, p = 0.002) higher prevalence of IPI occurred among HIV/AIDS patients (33.4%) compared to in HIV-ve patients (19.3%). Protozoan and helminthic parasites were the main parasites identified. Age, levels of education, income levels, smoking and drinking habits as well as dietary habits contributed significantly (p < 0.05 to increased prevalence of Intestinal parasitic infection among the HIV/AIDS patients. The study demonstrate that infection with HIV exacerbate intestinal parasitic infections (IPI). It is recommended that routine examination of stool samples for parasites would significantly benefit HIV infected and uninfected individuals by contributing to reduce morbidity
Farmers role in environmental conservation within the tea growing areas: A case of Rainforest Alliance
(2015) Kori, A.G.
SWEA-Dataveg – vegetation of small wetlands in East Africa
(2015-09-30) Kamiri, Hellen; Miguel, Alvarez; Bodo, Maria Möseler; Josko, Matthias; Becker, Mathias; Langensiepen, Matthias; Gunter, Menz; Beate, Böhme; Oyieke, Helida; Handa, Collins; Misana, Salome; Mwita, Emiliana; Mogha, Neema; Sakané, Nomé
SWEA (agricultural use and vulnerability of small wetlands in East Africa) is a multidisciplinary project which task is to evaluate the effects of land use on the ecological and socio-economical functions of small wetlands in Kenya and Tanzania. In order to allow the availability of the collected data for further studies we stored them into SWEA-Dataveg (GIVD ID AF-00-006), a database stored in Microsoft Access (mdb-format). Because this project is dealing not only with vegetation science but also with geography, soil science, hydrology and socio-economy, the database also contains information related to these research fields. Additionally, some functional traits of the plant species occurring in the relevés are included in the species list. The sampling areas are concentrated in four localities, two of them in Kenya (Karatina and Rumuruti) and two in Tanzania (Malinda and Lukozi). The vegetation ecology group is dealing in the project with the classification of the vegetation according to species composition, the correlation of plant communities with environmental factors and land uses, and the survey of potential indicator species for the determination of the resilience of wetlands. Once finished the storage, we are considering an adaptation of SWEA-Dataveg into a TURBOVEG-format as well as its extension to further projects (e.g. SWEA phase II) and relevés collected from publications.
Combined effects of photoperiod and temperature on growth and survival of African catfish (Clarias gariepinus, Burchell 1822) larvae under laboratory conditions
(Taylor and Francis, 2016) Okoth, Elijah Oyoo; Orina, Paul Sagwe; Rasowo, Joseph; Musa, Safina; Munguti, Jonathan M.; Karisa, Harrison Charo
The effect of photoperiod (24L:00D, 12L:12D, and 00L:24D) and temperature (22 ± 1°C and 28 ± 1°C) on performance of Clarias gariepinus larvae was tested. Larvae weighing 3.2 ± 0.24 mg were cultured in aquaria at a stocking density of 20 fish L−1 and fed twice a day on catfish starter diet (40% CP) at 10 % BW day−1. Highest mean weight gain (31.00 mg), SGR (7.56% day−1), and survival (83%) were achieved at photoperiod and temperature combination of 00L:24D and 28 ± 1°C. Percent survival of larvae differed significantly (p < .05) among treatments with optimal survival of (83%) in treatment combination of 28 ± 1°C and 00L:24D, while lowest survival (40%) in treatment combination of 22 ± 1°C and 24L:00D.
Species Richness and Abundance of Birds in and Around Nimule National Park, South Sudan
(The science publisher, 2016) Okoth, Elijah Oyoo; Simon, Gift Sarafadin
Impact of human activities on land degradation IN Lugari subcounty, Kakamega county, Kenya
(E3 Journals, 2016-10) Kinyanjui, Mwangi James; Wanjala, Wanyonyi Raphael
This study investigated the impact of human activities on land degradation in Lugari Sub-County, Kakamega County in Kenya. The study sought to analyze the extent of land degradation; identify the causative factors for land degradation and analyze the effect of implemented land conservation measures and propose sustainable land use options in Lugari Sub-County. The study used four Landsat satellite images; A Multi Spectral Scanner (MSS) of 1973, Landsat Thematic Mapper, TM of 1988, Enhanced Thematic Mapper, ETM of 2003 and Enhanced Thematic Mapper Plus, ETM+ of 2010 to develop time series land use and land use change maps of Lugari SubCounty. Data was confirmed by historical data and ongoing human activities from a socio economic survey and secondary sources. Soil erosion, soil fertility loss and pollution of the environment were associated with land use change. Correlations and regression were used to identify the human activities that have significant contribution to land cover change. Findings revealed that poor cultivation methods and traditional livestock grazing methods are the major factors contributing to land degradation. The study proposes the adoption of modern agricultural technologies to meet the nutritional, developmental and energy demands of the rural communities and ensures sustainable productivity of the land.
Environmental Determinants of Choice of Sustainability Strategies Adopted by Group Ranches in Samburu County, Kenya
(2017) Kithumbu, Eustace N.; Huho, Julius M.; Omondi, Humphrey R.
The group ranch system is one of the best land ownership and livestock production strategies Page | 153 in the dry lands of the world where the potential for rain-fed agriculture is limited. This has resulted in numerous studies on the establishment of group ranches, their dissolution and coping strategies but with less focus on the sustainability of the group ranches. It is against this background that this study investigated environmental characteristics influencing choice of sustainability strategies adopted by group ranches in Samburu County, Kenya. The investigation adopted a descriptive survey research design employing use of Questionnaires, Key Informant Interviews, Focus Group Discussions and observation as primary data collection methods. The study used content validity and Cronbach’s alpha methods to measure validity and reliability of the research instruments, respectively. The target population for the study was the 16,611 registered members in 38 group ranches spread out in the County. The study sampled twelve group ranches with approximately 5,643 members from which 374 respondents were systematically sampled. Purposive sampling was used to select Key Informants and the participants in the Focus Group Discussions. The study employed Multi-linear Regression to analyse environmental characteristics determining choice of sustainability strategies. The Analysis of Variance (ANOVA) was used to test the hypothesis and p-value of 0.00 was obtained, indicating that environmental characteristics significantly determined choice of sustainability strategies adopted by group ranches in the County. Overall, rainfall patterns were the predominating environmental characteristic with a regression coefficient of 0.317 while diseases had the least influence on choice of sustainability strategies adopted by group ranches in Samburu County, with a regression coefficient of 0.029. The study recommended integration of environmental characteristics in formulating policies for sustainability of group ranches.
Spatial scales influence long-term response of herbivores to prescribed burning in a savanna ecosystem
(CSIRO PUBLISHING, 2017-01) Kimuyu, Duncan M.; Sensenig, Ryan L.; Chira, Robert M.; Githaiga, John M.; Young, Truman P.
Both wild and prescribed fire in savanna ecosystems influence habitat use by herbivores by creating or maintaining spatial and temporal heterogeneity in forage quality and vegetation cover. Yet little is known about how spatial scales influence long-term persistence of fire effects. We examined changes over a 6-year period in herbivore preference for experimentally burned patches that varied in spatial extent and grain. Avoidance for the burns by elephants andpreferencefortheburnsbyimpalaandGrant’sgazelledecreasedsignificantly.Fortherestofthespecies(zebra,eland, oryx, hartebeest, warthog and hare), there were no significant changes in preference for the burns. Changes in preference for the burned areas depended on the spatial extent and grain of the burn, with intermediate-size (9-ha) burns and large (8-ha) patchy burns being more preferred 6–7 years after fire. Grain, but not the spatial extent of the burned area, influenced changes in grass height. Fire resulted in a delayed reduced tree density irrespective of the spatial scale of the burn. Results of this study indicate that, depending on the scale of fire prescription, the impacts of fire on herbivores may last longer than previous studies suggest