4 research outputs found
Contribution of Wetland Resources to Household Incomes of Riparian Communities of Katonga Wetland in Mpigi District, Uganda
Katonga wetland which lies to the western part of Lake Victoria covers an area of 237.4 km2. Although the wetland is known to contain flora and fauna that support livelihoods, there has been lack of information on the economic value of these resources and their contribution to livelihoods particularly of the rural riparian communities. The objective of the study was to generate information on the vital wetland resources, the economic value and contribution of these resources to riparian community livelihoods. The study was carried out in Nkozi and Kituntu sub-counties in Mpigi District-Uganda; it covered six parishes through which the wetland runs and involved 120 respondents. The study established that resources in the wetland are collected for subsistence and direct commercial extraction. The most important resource derived from the wetland for subsistence use was water for rural domestic use with each household using an average of 188l per day (23l per person) and was estimated at an annual economic value of Uganda shillings (Ushs) 490,191 (U 1,900.6) per person. These activities particularly collection of water and fuel wood are undertaken throughout the year, while harvesting of craft materials is mainly done during the dry season (January-March and June-August). Fishing is done mainly in the wet season (March-May and September-November).he wetland is a source of income for at least 74% of the respondents. The majority of respondents, 57.5%, were among low income groups earning up to Ushs 600,000 per respondent annually. Fishing provides the highest gross incomes per respondent Ushs 200,000 per month hence the high value of the wetland to its riparian communities. It was noted that 30% of respondents depend on both the wetland and other activities with the wetland providing a buffer income source. It is recommended that the wetland hydrology which is vital for the sustainability of these activities be maintained through catchment improvement while sustainable harvesting levels be established for fishing activities. Environment management structures should be strengthened to sustainably manage the wetland. Local communities should also be sensitized about the importance of this wetland so that they can appreciate its ecosystem services and participate in its sustainable management
Occurrence of Microcystin-Producing Cyanobacteria in Ugandan Freshwater Habitats
Microcystins (MCs) are cyclic heptapeptides, which are the most abundant toxins produced by cyanobacteria in freshwater. The phytoplankton of many freshwater lakes in Eastern Africa is dominated by cyanobacteria. Less is known, however, on the occurrence of MC producers and the production of MCs. Twelve Ugandan freshwater habitats ranging from mesotrophic to hypertrophic conditions were sampled in May and June of 2004 and April of 2008 and were analyzed for their physicochemical parameters, phytoplankton composition, and MC concentrations. Among the group of the potential MC-producing cyanobacteria, Anabaena (0-107 cells ml-1) and Microcystis (103-107 cells ml-1) occurred most frequently and dominated in eutrophic systems. A significant linear relationship (n = 31, r2 = 0.38, P < 0.001) between the Microcystis cell numbers and MC concentration (1.3-93 fg of MC cell-1) was observed. Besides [MeAsp3, Mdha7]-MC-RR, two new MCs, [Asp3]-MC-RY and [MeAsp3]-MC-RY, were isolated and their constitution was assigned by LC-MS2. To identify the MC-producing organism in the water samples, (i) the conserved aminotransferase domain part of the mcyE gene that is indicative of MC production was amplified by general primers and cloned and sequenced, and (ii) genus-specific primers were used to amplify the mcyE gene of the genera Microcystis, Anabaena, and Planktothrix. Only mcyE genotypes that are indicative of Microcystis sp. were obtained via the environmental cloning approach (337 bp, 96.1-96.7% similarity to the Microcystis aeruginosa strain PCC7806). Accordingly, only the mcyE primers, which are specific for Microcystis, revealed PCR products. We concluded that Microcystis is the major MC-producer in Ugandan freshwater