Browsing by Author "Abila, Romulus"
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Publication Genetic diversity and population structure of the African catfish, Clarias gariepinus (Burchell, 1822) in Kenya: implication for conservation and aquaculture(Belgian Journal of Zoology, 2017-10) Barasa, James E.; Mdyogolo, Sinebongo; Abila, Romulus; Grobler, Johannes Paul; Skilton, Robert A.; Bindeman, Hesmari; Njahira, Moses Ndotono; Chemoiwa, Emily J.; Dangasuk, Otto G.; Kaunda-Arara, Boaz; Verheyen, ErikAfrican catfish, Clarias gariepinus, is an important species in aquaculture and fisheries in Kenya. Mitochondrial D-loop control region was used to determine genetic variation and population structure in samples of C. gariepinus from 10 sites including five natural populations (Lakes Victoria (LVG), Kanyaboli (LKG), Turkana (LTA), Baringo (LBA) and Jipe (LJP), and five farms (Sangoro Aquaculture Center (SAN), Sagana Aquaculture Centre (SAG), University of Eldoret Fish Farm (UoE), Kibos Fish Farm (KIB), and Wakhungu Fish Farm (WKU)) in Kenya. Similarly, samples from eight localities (four natural populations: LVG/LKG, LTA, LBA, and four farmed: SAN, SAG, KIB, UoE) were genotyped using six microsatellite DNA loci. For the D-loop control region, samples from natural sites exhibited higher numbers of haplotypes and haplotype diversities compared to farmed samples, and 88.2% of haplotypes were private. All except LJP and LTA shared haplotypes, and the highest number of shared haplotypes (8) was detected in KIB. The 68 haplotypes we found in 268 individuals grouped into five phylogenetic clades: LVG/LKG, LTA, LBA, LJP and SAG. Haplotypes of farmed C. gariepinus mostly have haplotypes typical of LVG/LKG, and some shared haplotypes of the LBA population. Microsatellite analysis showed farmed samples have higher numbers of alleles than natural samples, but higher observed and expected heterozygosity levels were found in samples of natural Belg. J. Zool. 147 (2): 105–127 (2017) 106 populations. Fifteen pair-wise comparisons had significantly different FST values. All samples were in Hardy-Weinberg equilibrium. Samples from the eight localities grouped into four genetic clusters (LVG/ LKG, LTA, LBA and SAG), indicating genetically distinct populations, which should be considered for aquaculture and conservation
Publication Integrating stakeholder preferences into ecosystem services mapping in Yala wetland, Kenya(Taylor & Francis group, 2022-03-11) Githiora-Murimi, Yvonne Wambui; Owuor, Margaret Awuor; Abila, Romulus; Olago, Daniel; Oriaso, SilasWetlands such as the Yala swamp in Kenya are among the most important and increasingly threatened ecosystems globally due to their ecological significance and complexity, and the importance of the ecosystem services (ES) they provide to wetland communities. Appropriate governance and management of wetlands thus require the use of interdisciplinary tools that take into account both ecological and social considerations. This study used the matrix model combining social preferences with GIS-based maps of land use/land cover (LULC) to analyse the capacity of the Yala swamp to supply ES (flows). We engaged a total of 132 participants who manage and use natural resources in the wetland through a participatory process to identify ES, map LULC, and score the flow of ES on a scale of 0 to 5 using the matrix model. We also analysed the impacts of stakeholder characteristics (gender, environmental expertise, and location) on the scoring of the matrix. Results showed high average scores (score of 4) for trees and shrubs, papyrus, and water bodies across a range of provisioning, regulating and cultural services. The study found that gender and location had little influence on the respondents’ scores, while environmental conservation experts provided scores significantly higher than local resource users (farmers/fishermen) across the ES types. Overall, the study contributes to understanding: 1) the importance of linking LULC with ES provision to inform landscape management and 2) the need to incorporate a range of stakeholder perspectives in studies making use of expert knowledge and preferences, for inclusive management.Publication Perceptions, trends and adaptation to climate change in Yala wetland, Kenya(International Journal of Climate Change Strategies and Management, 2023-09-06) Githiora, Yvonne Wambui; Owuor, Margaret Awuor; Abila, Romulus; Oriaso, Silas; Olago, Daniel O.Purpose Tropical wetland ecosystems are threatened by climate change but also play a key role in its mitigation and adaptation through management of land use and other drivers. Local-level assessments are needed to support evidence-based wetland management in the face of climate change. This study aims to examine the local communities’ knowledge and perception of climate change in Yala wetland, Kenya, and compare them with observed data on climate trends. Such comparisons are useful to inform context-specific climate change adaptation actions. Design/methodology/approach The study used a mixed methods approach that combined analysis of climate data with perceptions from the local community. Gridded data on temperature and rainfall for the period from 1981 to 2018 were compared with data on climate change perceptions from semi-structured questionnaires with 286 key informants and community members. Findings Majority of the respondents had observed changes in climate parameters – severe drought (88.5%), increased frequency of floods (86.0%) and irregular onset and termination of rains (90.9%) in the past 20 years. The perceptions corresponded with climate trends that showed a significant increasing trend in the short rains and the average maximum temperature, high incidence of very wet years and variability in onset and termination of rainfall between 1981 and 2018. Gender, age and education had little influence on knowledge and awareness of climate change, except for frequency of floods and self-reported understanding of climate change. The community perceived the wetland to be important for climate change adaptation, particularly the provision of resources such as grazing grounds during drought. Research limitations/implications The study faced challenges of low sample size, use of gridded climate data and reproducibility in other contexts. The results of this study apply to local communities in a tropical wetland in Western Kenya, which has a bi-modal pattern of rainfall. The sample of the study was regional and may therefore not be representative of the whole of Kenya, which has diverse socioeconomic and ecological contexts. Potential problems have been identified with the use of gridded data (for example, regional biases in models), although their usefulness in data scarce contexts is well established. Moreover, the sample size has been found to be a less important factor in research of highly complex socio-ecological systems where there is an attempt to bridge natural and social sciences. Practical implications This study addresses the paucity of studies on climate change trends in papyrus wetlands of sub-Saharan Africa and the role of local knowledge and perceptions in influencing the management of such wetlands. Perceptions largely influence local stakeholders’ decisions, and a study that compares perceptions vs “reality” provides evidence for engagement with the stakeholders in managing these highly vulnerable ecosystems. The study showed that the local community’s perceptions corresponded with the climate record and that adaptation measures are already ongoing in the area. Originality/value This study presents a case for the understanding of community perceptions and knowledge of climate change in a tropical wetland under threat from climate change and land use change, to inform management under a changing climate.Publication Physico-chemical and bacteriological quality assessment of shallow wells in Kitui town, Kenya(Journal of Water Resource and Protection, 2012-01) Abila, Romulus; Mutemi, Muthangya; Mutuku, Eunice; Mutati, Kennedy; Munguti, Mutinda; Musyoka, CeciliaKitui town, a small but fast growing town in arid south-eastern Kenya faces unreliable water supply and residents are highly dependent on shallow wells as the main source of water for domestic use. A study was carried out to assess the physical-chemical and bacteriological quality of water from shallow wells within the town's main residential areas. 96 water samples were collected from 8 main residential estates within the town between May and July 2011 and analysed for physical-chemical characteristics and bacterial quantity and species. Water analysis revealed presence of 9 pathogenic genera including Salmonella, Escherichia coli, Vibrio, Listeria, Staphylococcus, Streptococcus, Enterobacter, Klebsiella and Pseudomonas. Multiple-tube fermentation technique was used to enumerate coliform bacteria in water. Total aerobic bacterial load ranged from 3.70 x10 2 to 2.352 x10 3 CFU/ml. E. Coli was isolated from Majengo and Mjini estates only and the bacterial load estimated as 1.10 x10 2 CFU/ml and 0.20 x10 2 CFU/ml respectively while Salmonella sp. was isolated from water samples from Kunda Kindu, JICA and Mjini estates. Conductivity and pH levels were above World Health Organization acceptable levels for drinking water in all samples. All samples tested did not meet the WHO bacteriological standards for drinking water. The presence of Salmonella, Vibrio, Listeria and E. Coli should particularly raise serious public health concerns over the quality of the town's shallow wells water. Intervention measures including creating awareness and educating residents on shallow well construction, citing and care, boiling of water and improving sanitation should be urgently instituted. There is also need to construct sewerage works for the rapidly expanding Kitui town to reduce incidences of contamination from septic tanks.Publication The role of the Yala swamp lakes in the conservation of Lake Victoria region haplochromine cichlids : Evidence from genetic and trophic ecology studies(Wiley, 2008-05-04) Abila, Romulus; Salzburger, Walter; Ndonga, Millicent; Owiti, Dickson; Barluenga, Marta; Meyer, AxelLake Kanyaboli, an isolated satellite lake of Lake Victoria, has been suggested as a potential refugium for haplochromine cichlids that have gone extinct in the main basin of Lake Victoria. Mitochondrial DNA (mtDNA) molecular markers, as well as feeding ecology studies, were employed in this study to re-evaluate the evolutionary and ecological significance of six common Lake Kanyaboli haplochromines. The mtDNA marker revealed high genetic variability within four of the six haplochromine cichlids. Five haplotypes were discerned in Astatoreochromis alluaudi (n = 27), seven in Lipochromis maxillaris (n = 29), five in Astatotilapia nubila (n = 12) and 11 in the endangered Xystichromis phytophagus (n = 205). A haplotype genealogy suggests that Lake Kanyaboli harbours mtDNA haplotypes that could have been lost or not sampled in Lake Victoria, or could have arisen in situ. Lipochromis maxillaris appears to have undergone a recent demographic expansion. The pairwise FSTs indicated that only the comparison between X. phytophagus and A. nubila led to a non-significant FST value. All other comparisons were significant at the 0.01 level, indicating the genetic distinctiveness of the haplochromines in the satellite lake. This could suggest that the lake harbours 'pure' relict populations of the haplochromines and therefore that Lake Kanyaboli can be considered a 'genetic reservoir'. Gut content analysis of the six haplochromine species revealed that eight different food items were consumed. No single species fed exclusively on a single food item, but certain food items contributed higher proportions of the fish diet for each fish species. Resource partitioning therefore could be discerned within this haplochromine community. Thus, Lake Kanyaboli and similar satellite lakes provide an opportunity for conservation of both genetic and trophic diversity threatened by introduction of exotics in the Lake Victoria basin. Lake Kanyaboli should be recognized and conserved as important evolutionary significant units for Lake Victoria region haplochromine species.