16,911 research outputs found
Women and gender participation in the fisheries sector in Lake Victoria
No full textRole of women, Fisheries, GENDER, Lake Victoria,
The invasion of an introduced predator, Nile perch (Lates niloticus, L.) in Lake Victoria (East Africa): chronology and causes
No full textNile perch, a large predatory fish, was introduced into Lake Victoria in 1954. The upsurge of Nile perch in Lake Victoria was first observed in the Nyanza Gulf, Kenya, in 1979. In Ugandan waters this occurred 2¿3 years later and in the Tanzanian Mwanza Gulf 4¿5 years later. At the beginning of the upsurge in the Mwanza Gulf in 1983/1984 only sub-adult and adult fishes were found. The first juveniles appeared in 1985, suggesting that the initial increase of Nile perch was mainly caused by migration of sub-adults and adults. Shortly after the onset of trawl fishery in the area in 1973, haplochromines in the Mwanza Gulf started to decline. The final disappearance of the haplochromines, in 1987, only occurred after the Nile perch boom, and despite the abandoning of the haplochromine fishery in 1986. We hypothesize that the decline of haplochromines decreased predation on and competition with juvenile Nile perch and then facilitated survival of these juveniles. Consequently the immigration of sub-adult and adult Nile perch in an area may have paved the way for successful recruitment. Over-exploitation of haplochromine cichlids in the 1970s in the Nyanza Gulf, where the Nile perch upsurge was first observed, may have played a similar role
Final Report on establishment of the Lake Victoria fisheries database
No full textThe Lake Victoria Environmental Management Project (LVEMP) funded by theGEF, World Bank and the three East African Partner States (Kenya, Tanzaniaand Uganda) established a Regional Task Force (RTF) on Lake Victoria fisheriesin September 1999. The Task Force was charged with the responsibility ofidentifying and elaborating methodologies for setting up a Lake Victoria FisheriesDatabase. The Task Force comprised of individuals drawn from key fisheriesagencies in the region and information specialists from the LVEMP NationalSecretariats in Kenya, Tanzania and Uganda
A Predator-Prey Model with an Application to Lake Victoria Fisheries
No full textGreater complexity in renewable resource models is achieved by acknowledging that species interact through a predator-prey relationship in which both species are harvested. The price of greater complexity is that traditional concepts, such as maximum sustained yield (MSY), have to be revised dramatically. Moreover, having chosen greater complexity, fishery biologists and other researchers must choose an explicit value for each fish, a rate of exchange of one species for every other species. Policy makers and social scientists in Tanzania, Kenya, and Uganda with a keen interest in Lake Victoria fisheries regard the resource as a tool for furthering socioeconomic goals, such as foreign exchange earnings, employment for women, and nutrition. Comparative analysis allows policy makers to understand the consequences of choosing these goals in addition to economically efficient resource use. Foreign exchange earnings, employment for women, and healthy people are other goals promulgated by Tanzania, Kenya, and Uganda in the management of Lake Victoria Fisheries. The conflicts among social goals are evident in the bioeconomic predator-prey model: a goal favoring a particular species reduces the sustainable harvest of another species. Data from Kenya are used to estimate the population dynamics equations.predator-prey, bioeconomic model, Lake Victoria, Resource /Energy Economics and Policy, Q22, Q28,
Impacts of irrigation and hydroelectric power developments on the Victoria Nile in Uganda
No full textThis research aimed at increasing the understanding of the water resources of
the Victoria Nile basin and assessing the impact of irrigation and hydropower
developments on the Victoria Nile under different rainfall regimes. A Bayesian
Network constructed with the HUGIN expert researcher software version 6.9 was
used as the decision tool. The Network used a mixture of data, information from
previous studies and consultation with experts/stakeholders. A network consisting
of 21 nodes was developed and run to determine the impacts of different
development scenarios.
The Victoria Nile basin in Uganda is the first recipient of the river Nile flow as it
leaves Lake Victoria. In this basin, there is potential for 5 large hydroelectric
power plants and the basin consists of 70% of the irrigation potential in Uganda
and yet it is one of the most lacking in hydrological data in the Nile basin. Further
downstream of this basin are two riparian states, Egypt and Sudan which
according to the prevailing legislation on the use of the Nile share amongst
themselves the entire river flow.
The research shows that Irrigation and hydropower developments have modest
effects on lake levels and river flows exiting the basin. Rainfall occurrence on the
other hand has the largest effect on the lake levels and Victoria Nile river flow
exiting the basin. It is shown that in situations of very high water demand, which
occurs when annual rainfall is less than 1,200 mm, full irrigation potential is
utilized and all 5 hydroelectric power plants are developed, irrigation water need
is not more than 7% of the Nile flow from the basin. The effects of hydropower
plants are manifested mainly in the socioeconomic impacts in their vicinity, which
are found to be large and to increase with the number of plants developed. The
current mode of operation of outflows from Lake Victoria which is based on an
international agreement between Uganda and Egypt is a satisfactory means of
control only during moderate rainfall events and lake levels. However, for
extreme conditions of lake levels outside the range of 10.8-11.6 m it is
inadequate under increasing demands of hydroelectric power generation
Strategic Action Programme (SAP) for the Lake Victoria Basin 2006
No full textThe Lake Victoria Basin (LVB) has a size of 193 000 km2, with the Lake surface covering anarea of 68,800 km2 (Fig. 1). The basin area is shared between riparian states of Tanzania(44%), Kenya (22%), Uganda (16%), Burundi (7%) and Rwanda (11%). The Lake itself isshared between Kenya (6%), Tanzania (51%) and Uganda (43%). LVB has recentlydisplayed a massive ecosystem change in a relatively short (three decade) period(Kaufman1992; Goldschmidt et al 1993; Goldschmidt 1996; Verschuren et al. 2002). Thechanges have been induced by natural factors coupled with human activities mainlyassociated with increasing population, economic growth and governance
Lake Victoria Fisheries Service Annual Report 1959/60
No full textThe Annual report provides information on work carried out on Lake Victoria by the Lake Victoria Fisheries Service during the period 1959/60. It provides annual catch statistics, fisheries control and legislation
Growth, mortality and recruitment of Nile perch Lates niloticus (L. Centropomidae) in the Nyanza Gulf of Lake Victoria: an evaluation update
No full textA reassessment of the estimates of growth, mortality and recruitment patterns of Nile Perch, Lates niloticus was made based on data from commercial landings collected during the Catch Assessment Survey Programme. Two sets of length frequency data, one each from beach seining and hook and line fisheries, were analyzed. Values of L8 = 169 and 230 (cm TL) and K= 0.18 yr-1 and 0.195 yr-1 were obtained. The total mortality estimates from the catch curve analysis were Z = 0.72 yr-1 and 0.94 yr-1, respectively, with a natural mortality M of about 0.35 for a mean environmental temperature of 27oC. The highest peak for recruitment was in November, December and January with a minor one in June, indicating recruitment of two cohorts per year. These results are discussed and compared to previously available information on L. niloticus in Lake Victoria.Growth, Mortality, Recruitment, Kenya, Victoria L., Nyanza Gulf, Lates niloticus
A review of herbicide use in the control of water hyacinth with recommendations on possible use in Lake Victoria
No full textLake Victoria, which is socioeconomically important to the riparian states of Kenya, Uganda, Tanzania, and to the global global community, has a surface area of 68,000 km2while the adjoining lake catchment area measures 184,000 km2. The gross domestic product of the catchment is estimated at US $ 3-4 billion and supports an estimatedpopulation of 25 million people. The lake is used as a source of food, hydropower, drinking and irrigation water, transport and tourism. Major threats facing Lake Victoria include the problem of pollution and water hyacinth
Low Malnutrition but High Mortality: Explaining the Paradox of the Lake Victoria Region
No full textExploiting DHS data from 235 regions in 29 Sub-Saharan Africa countries, we find that the combination of low levels of malnutrition together with dramatically high rates of mortality, encountered in Kenya\'s Lake Victoria territory, is unique for Sub-Saharan Africa. This paper explores the causes of this paradox for the Kenyan context. Our identification strategy consists of two parts. First of all, we apply multilevel regression models to control simultaneously for family and community clustering of the observed malnutrition and mortality outcomes. Secondly, to address unobserved but correlated factors, we exploit information from GIS and malaria databases to construct variables that capture additional components of children\'s geographic, political and cultural environment. Our analysis reveals that beneficial agricultural conditions and feeding practices lead to the observed sound anthropometric outcomes around Lake Victoria. In contrast, high mortality rates rest upon an adverse disease environment (malaria prevalence, water pollution, HIV rates) and a policy neglect (underprovision of health care services). Nonetheless, a significant effect of the local ethnic group, the Luo, on mortality remains.Child mortality, undernutrition, poverty, multilevel modeling, Sub-Saharan Africa
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