Browsing by Author "Muyodi, Fredrick J."

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    Effect of water hyacinth on distribution of sulphate-reducing bacteria in sediments of Lake Victoria
    (Water SA, 2004) Muyodi, Fredrick J.; Rubindamayugi, Mugassa S. T.; Semesi, Adelaide K.
    The effect of the water hyacinth, Eichhornia crassipes (Mart.) Solms-Laub, on the distribution of populations of sulphate-reducing bacteria (SRB) in sediments from various stations on the shores of Lake Victoria around Mwanza Municipality, Tanzania, was studied. Lactate-utilising SRB were observed to be the dominant species in sediments covered by the water hyacinth and at the Mirongo River mouth while acetate-utilising SRB dominated in the offshore open water sediments. Sediments from offshore open waters had the lowest most probable numbers (MPNs) for all the SRB types investigated, more than 100 times less that observed in areas covered by the water hyacinth and the Mirongo River mouth. Lactate-utilising SRB were almost absent in sediments from offshore open waters. A positive correlation between the total populations of SRB and nutrients in sediments was observed. Results showed that sulphate concentration was very high in sediments underneath the water hyacinth at the lakeshore but was minimal in sediments from offshore open waters. It is suggested that water hyacinth decomposition formed lactate, which supported large populations of lactate-utilising SRB.
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    Experiences and lessons learned from interventions in the Lake Victoria Basin: The Lake Victoria Environmental Management Project
    (Lakes & Reservoirs: Research & Management, 2010) Muyodi, Fredrick J.; Bugenyi, Fredrick W. B.; Hecky, Robert E.
    The Lake Victoria basin has experienced a myriad of environmental changes leading to its degradation, and necessitating various interventions to be implemented. The purpose of this study was to review early development initiatives, past and ongoing interventions in order to document experiences and lessons learned from them. The methods used in this study include review of published articles, project reports, and personal opinions of experts and project implementers in the lake basin. There are numerous threats to the lake basin, the major ones being poor land use and agricultural practices, catchment deforestation, destruction of wetlands, pollution loading, fishing malpractices and invasion by exotic aquatic weeds. These threats have resulted in rampant land and wetland degradation, leading to poor water quality and consequent water loss, a decline in the diversity of the commercial fisheries, and the lake’s biodiversity in general, unsustainable use of natural resources, increased poor human health and food insecurity, with high levels of poverty among the riparian communities. Initiatives for socio-economic development within the lake basin began as early as the turn of the 20th century, while intervention studies started as early as the 1920s. Current lake management intervention projects, such as the Lake Victoria Environmental Management Project (LVEMP), undertaken by the riparian states of the East African Community, have invested heavily in the lake basin, with the goal of addressing the above-noted threats to the lake. Some pilot projects undertaken through the LVEMP include: (i) water quality and quantity monitoring; (ii) industrial and municipal management; (iii) fisheries studies; (iv) water hyacinth control; (v) wetlands; (vi) land use; (vii) catchment afforestation; and (viii) micro-projects to alleviate poverty, to cite a few examples. Phase 1 of the LVEMP was a major effort in the history of the lake basin; hence, its critical examination. To this end, this study highlights, in chronological order, the experiences, achievements, challenges and lessons learned with regard to Phase 1 of the LVEMP.
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    Occurence of Culturable Vibrio cholerae from Lake Victoria, and Rift Valley Lakes Albert and George, Uganda
    (Lakes & Reservoirs: Research & Management, 2012) Kaddumukasa, Martha; Nsubuga, David; Muyodi, Fredrick J.
    Vibrio cholerae, a bacterium that causes cholera, poses a human health risk when consumed via untreated or contaminated water. Monthly investigations into the presence of V. cholerae from Lakes Albert, George and Victoria were conducted, with the goal being to examine the relationship between the occurrences of V. cholerae with various water quality parameters at fish landing sites in major water bodies in Uganda. The pH, temperature and electrical conductivity were measured at three fishing sites in each of the three study lakes; namely Gabba in Lake Victoria, Butiaba in Lake Albert and Kayanzi in Lake George. The pH values varied from 7.76 to 9.36 at Butiaba, 8.68 to 9.85 at Kayanzi and 6.6 to 9.88 at Ggaba. The temperature ranged from 17.9 to 32.3 C at Butiaba, 22.5 to 29 C at Kayanzi and 18.2 to 30.5 C at Ggaba. The electrical conductivity ranged from 129.2 to 984 lS cm)1 at Butiaba, 658 to 1090 lS cm)1 at Kayanzi and 119 to 218 lS cm)1 at Ggaba, for Lakes Albert, George and Victoria, respectively. Enrichment techniques were used to detect culturable V. cholerae on TCBS culture media. Seventy-five (75%) of the samples (n = 90) were positive for V. cholera. The occurrence of V. cholerae was positively associated with water quality parameters over the 10-month period of study. Vibrio cholerae was more frequently detected during the dry season (warmer) than during the wet season. These study results suggest the investigated study lakes are natural reservoirs for V. cholerae.
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    Trends in health risks from water-related diseases and cyanotoxins in Ugandan portion of Lake Victoria basin
    (Research & Management, 2009) Muyodi, Fredrick J.; Hecky, Robert E.; Mukisa Kitamirike, Jackson; Odong, Robinson
    Studies to examine the prevalence of water-related diseases, cyanobacteria toxins and other health risks at landing beaches in the Ugandan portion of the Lake Victoria basin were carried out. Based on surveillance studies and other data sources in the region, water samples were analysed for indications of faecal contamination. The coliform numbers were generally high for most sampling sites, indicating significant water contamination. The wet seasons exhibited significantly higher coliform counts than the dry seasons for all lakeshore sample sites. This seasonal variation in coliform counts correlated positively with the incidence of waterborne diseases, which are typically higher in the wet season. The water supply for domestic consumption for the Lake Victoria riparian communities is mainly the lake itself. The most prevalent diseases associated with the landing sites include malaria, dysentery, diarrhoea and bilharzia. Malaria was most prevalent, followed by dysentery, in all the studied districts. Many people in the catchment dispose of faecal wastes in lakeshore area bushes, or in polythene bags, contaminating water sources with faecal material, and resulting in waterborne diseases. The vulnerability of lakeside communities to water-related diseases is further aggravated by low accessibility to health facilities and personnel. Further, cyanobacteria (potentially toxic to humans and animals) dominate other algal species in Lake Victoria, contributing >50% of the algal biomass. Algal blooms occurred frequently in Murchison Bay, a source of drinking water for the city of Kampala and surrounding urban centres. Algal blooms can cause unpleasant odours and tastes in domestic water supplies, clog pump and machinery filters, increase chlorine demands for water disinfection, and necessitate more complex and expensive treatment processes. The findings of this study suggest improved water quality, changes in sanitation and hygiene behaviour could significantly reduce the prevalence of water-related diseases and cyanotoxins in the Ugandan portion of the Lake Victoria basin