Recent Submissions

  • Impact of dead and sunken water hyacinth on biotic communities, the aquatic environment and socioeconomic activities

    Ogutu-Ohwayo, R.; Balirwa, J.S.; Twongo, T.; Mugidde, R.; Odongkara, C. (Fisheries Resources Research InstituteJinja, Uganda, 2002)
    The mobile water hyacinth, which was produced in growth zones, especially Murchison bay, was mainly exported to three sheltered storage bays (Thruston, Hannington and Waiya). Between 1996 and May 1998, the mobile form of water hyacinth occupied about 800 ha in Thruston bay, 750 ha in Hannington bay and 140 ha in Waiya bay). Biological control weevils and other factors, including localised nutrient depletion, weakened the weed that was confined to the bays and it sunk around October 1998. The settling to the bottom of such huge quantities of organic matter its subsequent decomposition and the debris from this mass was likely to have environmental impacts on biotic communities (e.g. fish and invertebrate), physico-chemical conditions (water quality), and on socio-economic activities (e.g. at fish landings, water abstraction, and hydro-power generation points). Sunken water hyacinth debris could also affect nutrient levels in the water column and lead to reduction in the content of dissolved oxygen. The changes in nutrient dynamics and oxygen levels could affect algal productivity, invertebrate composition and fish communities. Socio-economic impacts of dead sunken weed were expected from debris deposited along the shoreline especially at fish landings, water abstraction and hydropower generation points. Therefore, environmental impact assessment studies were carried out between 1998 and 2002 in selected representative zones of Lake Victoria to identify the effects of the sunken water hyacinth biomass.
  • Socio-economic aspects of the fisheries of Nabugabo lakes and implications for management

    Lubuulwa, M. (Fisheries Resources Research InstituteJinja, Uganda, 2002)
    Fisheries are very important to Uganda's economy. The sector provides a vital source of food, recreation, trade and socioeconomic well being for the people and community globally. The fisheries of small lakes are important for producing fish for local populations who are not near the large lakes. These satellite lakes support important fisheries and other economic activities like fishing, water for domestic purposes and tourism, besides socio-cultural values. A number-of fish;-species, some of which were found only in Lake Victoria have been depleted through over-exploitation, introduction of exotics especiaily Nile perch and environmental degradation. Some of these fishes have been observed to survive in satellite lakes in the Victoria and Kyoga Lake basins. The Nabugabo satellite lakes (Manywa, Kayugi and Kayanja) contain endemic Cichlid fish species acting as reservoirs and therefore very important for conservation of fish biodiversity.Despite the socio-economic importance and uniqueness of these satellite lakes little research on socio-economic studies has been carried out. The sustainability of the lake is being threatened by increasing human activities. The fish stocks and species diversity are declining and this poses a threat to the livelihood of the people who depend on fish for food and income. Arising from this need a study was carried out to establish the socio-economic aspects of Nabugabo fisheries and implications for management, on which basis resource users would be made aware of the impacts of their activities. It was hoped that this would go further to ensure wise use and management of the resources by the users. The specific objectives were identifying activities around the lake, establishing socioeconomic values attached to the lake, identifying problems of the lake and resource users and examining existing local based management institutions.Results show that the activities taking place around the lakes include fishing, farming, watering of animals, deforestation and charcoal burning, brick making, resort beach development and food and refreshment. The major problem facing the lake was found to be encroachment of Hippo grass (Vossia) on the lake, which is decreasing the size of the lake, and limiting open waters for fishing (this only applied to Lake Nabugabo). Other important problems include use of illegal fishing methods, declining fish stocks and loss of cultural identity. The resource users are most pressed by the low incomes resulting from poor fish catches, theft of gears and lack of market. On examining the resource base for the lakes, it was only Lake Nabugabo that had a Landing Management Committee. The other three lakes did not have leadership institutions in place except the local councils for the respective villages. This was probably due to observed limited fisheries activities. Majority of the respondents agreed that Government and other service providers should work jointly to supplement local beach management committees in the management of the lakes resources. This is a good gesture because with increase in fishing effort and rampant use of illegal fishing methods, there is need to strengthen management institutions present on the lake. This would require Government, local community and other service providers to work together in a participatory way to control environment-degrading activities and stop the use of illegal fishing methods. Burning of vegetation on the lake should be stoppedsince it enhances growth of this grass. Finally, traditional taboos; which are present on some of the Nabugabo lakes, should be enhanced, as away ofpreserving them.
  • Contribution of biological control in management of water hyacinth

    Ogwang, J.; Molo, R. (Fisheries Resources Research InstituteJinja, Uganda, 2002)
    Biological control was foreseen as the long-term strategy for controlling water hyacinth in Uganda. Two species of weevils, Neochetina eichhorniae and Neochetina bruchi were imported into Uganda from Benin (West Africa) in 1993. A total of 600 weevils of each species were imported. The weevils were tested for specificity using key agricultural crops including maize, beans and bananas and were found to be water-hyacinth specific for their food and reproduction.
  • Environmental factors influencing composition, abundance and distribution of water hyacinth

    Mugidde, R.; Wanda, F. (Fisheries Resources Research InstituteJinja, Uganda, 2002)
    Relationships between nutrient concentrations and water hyacinth biomass and composition have been studied in the shallow inshore bays of lakes Victoria, Kyoga and Albert. Additional information was obtained from Victoria Nile, Albert Nile and Kagera River. In this section, seasonal changes in nutrients and oxygen concentrations are used to explain changes in water hyacinth composition, biomass and distribution in Lake Victoria. Lake Victoria is of particular interest because it experienced strong hyacinth infestations in 1995, a sink in 1998 and resurgence in 2001. The lake has also been extensively sampled and provides time series data in nutrient, oxygen, mixing and thermal stratification which provide an opportunity to relate water hyacinth distribution and biomass to environmental factors. The possible origins and impacts of nutrient loads into Lake Victoria are also discussed in relation to water hyacinth proliferation and distribution especially in relation to known 'hot-spots'.
  • Knowledge, perceptions, impacts and role of lakeside communities and institutions in the sustainable control of water hyacinth.

    Odongkara, K.O.; Kyangwa, M.; Kulyayingi, V. (Fisheries Resources Research Institute (FIRRI)Jinja, Uganda, 2002-04)
    The massive water hyacinth mats that covered water bodies in the 1990s had serious social and economic impacts. They affected fishing, transportation, water quality and health of fishing communities as well as production of goods and services of lake-based institutions (commercial establishments). At peak infestations, the communities and institutions were aware of and participated readily in control effort. However, after the major collapse of hyacinth in 1998, some of them relaxed in their control efforts. The status of knowledge, perception, impacts, preparedness and role of the lakeside communities and institutions to control the weed has, therefore, been monitored since the major resurgence of the weed to find out if the lakeside communities and institutions still perceive water hyacinth as a problem and the extent to which they are prepared to sustain control
  • Impact of dead and sunken water hyacinth on biotic communities, the aquatic environment and socio-economic activities

    Ogutu-Ohwayo, R.; Balirwa, J.S.; Twongo, T.; Mugidde, R.; Odongkara, O. (Fisheries Resources Research InstituteJinja, Uganda, 2002)
    The mobile water hyacinth, which was produced in growth zones, especially Murchison Bay, was mainly exported to three sheltered storage bays (Thruston, Hannington and Waiya). Between 1996 and May 1998, the mobile form of water hyacinth occupied about 800 ha in Thruston Bay, 750 ha in Hannington Bay and 140 ha in Waiya Bay). Biological control weevils and other factors, including localised nutrient depletion, weakened the weed that was confined to the bays and it sunk around October 1998. The settling to the bottom of such huge quantities of organic matter its subsequent decomposition and the debris from this mass was likely to have environmental impacts on biotic communities (e.g. fish and invertebrate), physico-chemical conditions (water quality), and on socio-economic activities (e.g. at fish landings, water abstraction, and hydro-power generation points). Sunken water.hyacinth debris could also affect nutrient levels in the water column and lead to reduction in the content of dissolved oxygen. The changes in nutrient dynamics andoxygen levels could affect algal productivity, invertebrate composition and fish communities. Socio-economic impacts of dead sunken weed were expected from debris deposited along the shoreline especially at fish landings, water abstractionand hydropower generation points. Therefore, environmental impact assessment studies were carried out between 1998 and 2002 in selected representative zones of Lake Victoria to identify the effects of the sunken water hyacinth biomass
  • Poverty within the fisheries: indicators, causes and interventions. Draft 2

    Odongkara, O.K. (National Fisheries Resources Research Institute (NaFIRRI)Jinja, Uganda, 2002-05)
    The study is prompted by the poverty that has persisted among the fishing communities of Lake Victoria at a time of considerable cash inflow into the fisheries from the development of the fish processing industry. There has been need for an understanding of the poverty and what strategies would be most appropriate for its reduction. This study has attempted torespond to the need by identifying the nature and distribution of the poverty within thefisheries of Lake Victoria, Uganda, the factors responsible for it and the options for povertyreduction intervention.
  • Assessment of the pre-project situation and; implementation process of LVEMP micro-projects

    Namisi, P.W.; Lubuulwa, M.; National Agricultural Research Organisation; Lake Victoria Environment Management Project (Fisheries Resources Research Institute (FIRRI)Jinja, Uganda, 2002-05)
    Micro-projects is a component of the LVEMP project that aims at improving thelivelihoods of the poor communities around the lake's basin through empowering thecommunities to construct and rehabilitate their basic socio-economic infrastructuresfrom which the communities can benefit and; empowering them to safeguard theirresources. Twenty micro-projects under LVEMP in Uganda were assessed to establishthe pre-project situation, the process of implementation, planning and sustainability ofthe micro projects.
  • Institutional arrangements for management of water hyacinth. FIRRI Technical Document, Draft 2, April 2002

    Ogutu-Ohwayo, R. (National Fisheries Resource Research InstituteJinja, Uganda, 2002-04)
    Institution arrangements for the control and management of water hyacinth took at least three years to take effect probably because the original Government objective was to formulate an eradication-focussed strategy.
  • Appropriate fishing gears for exploiting Nile Perch, Nile Tilapia and Mukene

    Ogutu-Ohwayo, R.; Wandera, S.B.; Kamanyi, J.R. (National Fisheries Resource Research InstituteJinja, Uganda, 2002-04)
    Catch effort data on which fisheries management regulations are sometimes basedare not available for most lakes in Uganda. However, failure to regulate fishing gearsand methods has been a major cause of collapse of fisheries in the country. Fisherieshave been damaged by destructive and non-selective fishing gears and methods suchas trawling and beach seining, by use of gill nets of mesh size which crop immaturefish and by introduction of mechanised fishing. Selectivity of the gears used to cropLates niloticus L. (Nile perch), Oreochromis niloticus L. (Nile tilapia) and Rastrineobolaargentea (Mukene) which are currently the most important commercial species inUganda were examined in order to recommend the most suitable types, sizes andmethods that should be used in exploiting these fisheries. Gill nets of less than 127mm mainly cropped immature Nile tilapia and Nile perch. To protect these fisheries,the minimum mesh size of gill nets should be set at 127 mm. Seine nets of 5 mm docatch high proportions of immature Mukene while those of 10 mm catch mainly matureMukene. When operated inshore, both sizes catch immature Nile perch and Niletilapia as by-catch. To protect the Mukene fishery and avoid catching immature byecatch,a minimum mesh size of the Mukene net should have been 10 mm operated asLampara type net offshore but since most fishermen have been using the 5 mm seinefor over five years the minimum size should not be allowed to drop below 5 mmpending further thorough investigations. Beach seining, trawling and are destructive tofisheries and should be prohibited until data that may justify their use is available.
  • Economic losses/gains attributed to the water hyacinth

    Kulyanyingi, V. (Fisheries Resources Research Institute (FIRRI)Jinja, Uganda, 2002)
    This is the report of a research study aimed at providing an understanding of the fishing communities and institutions about the water hyacinth problem and how it impacts on their activities. Its also provides strategies for sustainable control of the weed.The research reports are intended to disseminate the findings of the studies carried out under the Socio-economics Sub-component of LVEMP to a wide spectrum of users, including policy makers, stakeholders and researchers.
  • Technical guidelines for management of fisheries resources, biodiversity and environment of Victoria basin lakes

    Ogutu-Ohwayo, R.; Mugidde, R.; Balirwa, J.S. (Fisheries Resources Research Institute (FIRRI)Jinja, Uganda, 2002)
    Lake victoria is the second largest lake in the world.the lake is shatred between three East African countries (Kenya,Uganda and Tanzania) the lake basin is estimatedto have about 30 million people who depend on it as a source of fish for food,employment,income and recreation.the lake is transport locally and regionally is used for recreation and is recongnised internationally for its high fish species diversity of ecological and scientific value.This document in the first in a series to be produced on different fish production systems in Uganda and should stimulate discussions and comments to guide application of scientific findings into the policy environment.
  • Socio-cultural influences on sanitation, fish handling and artisanal fish processing within the fishing communities

    Odongkara, K.O.; Kyangwa, I.; Nasuuna, A. (Fisheries Resources Research InstituteJinja, Uganda, 2002)
    The fishery sector in Uganda has seen important changes in the last two decades. Among the changes registered, is the expansion of fish markets locally, regionally and internationally. Upon which, remarkable benefits have been realized at local and national levels, for instance, it is estimated that an average of 40m$ is being earned annually as foreign exchange. Besides, presently fish accounts for over 50% of total animal protein in take. However, it is argued that sustaining these gains has become an up hill task due to failure to maintain fish quality as a result of the rudimentary and inappropriate sanitary, fish handling and artisanal fish processing practices that both directly and indirectly affect the quality of fish and fish products.Therefore, against this background, a study of 507 respondents was undertaken among the Lake Victoria Communities specifically in Wakiso, Mayuge and Mukono districts. The study examined the perceptions of fishers on the social cultural practices of sanitation, fish handling and artisanal fish processing and consequently identified factors that influenced these practices.