Lake Victoria

Abstract: In Lake Nabugabo, Uganda, a small satellite of the equatorial Lake Victoria, approximately 50% of the indigenous fish species disappeared from the open waters subsequent to establishment of the introduced predatory Nile perch (   Lates niloticus ). However, several of these species persisted in wetland refugia. Over the past decade, Nile perch in Lake Nabugabo have been intensively fished. Herein we report a resurgence of some indigenous species in open waters. In a multiyear study, we used annual transects in inshore and offshore waters of exposed ( no wetland ) and wetland habitats to document the pattern of resurgence. In 1995, haplochromine cichlids were largely confined to inshore areas, particularly wetland ecotones, and were rare in Nile perch stomachs, as were most other indigenous species. By 2000 haplochromine cichlids were abundant in inshore and offshore areas of both exposed and wetland transects. Several indigenous noncichlids also reappeared in the main lake, including three of the four original mormyrid species. Between 1995 and 1999, there was a dramatic increase in the proportion of haplochromines in the diet of Nile perch. When haplochromines were rare ( 1995 ), Nile perch switched from an invertebrate-dominated diet to piscivory at a large size ( 30 cm total length ). In 2000, however, Nile perch were strongly piscivorous by 5–10 cm total length. The pattern of faunal loss and recovery in Lake Nabugabo demonstrates the importance of refugia in providing the seeds of resurgence and provides a model with which to understand some changes in Lake Victoria.Resumen: En el Lago Nabugabo, Uganda, un pequeño satélite del lago ecuatorial Victoria, el 50% de las especies indígenas de peces, aproximadamente, desaparecieron de aguas abiertas después del establecimiento de la perca del Nilo (   Lates niloticus ); una especie depredadora introducida. Sin embargo, varias de estas especies persistieron en refugios de humedales. En el transcurso de la última década la perca del Nilo en el lago Nabugabo ha sido pescada intensivamente. En este documento presentamos información sobre el resurgimiento de algunas especies indígenas en aguas abiertas. En un estudio, a lo largo de varios años, usamos transectos anuales en aguas cercanas a la orilla y en aguas abiertas de hábitats expuestos (no humedales) y hábitats de humedal para documentar el patrón de resurgimiento. En 1995, los cíclidos haplocróminos fueron en su mayoría confinados a las áreas cercanas a las orillas, especialmente ecotonos de humedal, y fueron raros en los estómagos de perca del Nilo, así como lo eran la mayoría de las otras especies nativas. Para el año 2000 los cíclidos haplocróminos fueron abundantes tanto en las áreas cercanas a las orillas como en aguas abiertas de transectos expuestos y humedales. Muchas especies no-cíclidos también reaparecieron en el lago principal, incluyendo tres de las cuatro especies de mormíridos. Entre 1995 y 1999, hubo un dramático aumento en la proporción de haplocróminos en la dieta de la perca del Nilo. Cuando los haplocróminos fueron raros ( 1995 ), la perca del Nilo cambió de una dieta dominada por invertebrados a una dieta fuertemente piscívora a un tamaño grande ( 30 cm de longitud total ). Sin embargo, en el año 2000, la perca del Nilo fue fuertemente piscívora entre los 5 y 10 cm de longitud total. El patrón de pérdida de fauna y recuperación del lago Nabugabo demuestra la importancia de refugios para proveer las semillas del resurgimiento y provee un modelo para entender algunos cambios en el Lago Victoria.Resumen: En el Lago Nabugabo, Uganda, un pequeño satélite del lago ecuatorial Victoria, el 50% de las especies indígenas de peces, aproximadamente, desaparecieron de aguas abiertas después del establecimiento de la perca del Nilo (   Lates niloticus ); una especie depredadora introducida. Sin embargo, varias de estas especies persistieron en refugios de humedales. En el transcurso de la última década la perca del Nilo en el lago Nabugabo ha sido pescada intensivamente. En este documento presentamos información sobre el resurgimiento de algunas especies indígenas en aguas abiertas. En un estudio, a lo largo de varios años, usamos transectos anuales en aguas cercanas a la orilla y en aguas abiertas de hábitats expuestos (no humedales) y hábitats de humedal para documentar el patrón de resurgimiento. En 1995, los cíclidos haplocróminos fueron en su mayoría confinados a las áreas cercanas a las orillas, especialmente ecotonos de humedal, y fueron raros en los estómagos de perca del Nilo, así como lo eran la mayoría de las otras especies nativas. Para el año 2000 los cíclidos haplocróminos fueron abundantes tanto en las áreas cercanas a las orillas como en aguas abiertas de transectos expuestos y humedales. Muchas especies no-cíclidos también reaparecieron en el lago principal, incluyendo tres de las cuatro especies de mormíridos. Entre 1995 y 1999, hubo un dramático aumento en la proporción de haplocróminos en la dieta de la perca del Nilo. Cuando los haplocróminos fueron raros ( 1995 ), la perca del Nilo cambió de una dieta dominada por invertebrados a una dieta fuertemente piscívora a un tamaño grande ( 30 cm de longitud total ). Sin embargo, en el año 2000, la perca del Nilo fue fuertemente piscívora entre los 5 y 10 cm de longitud total. El patrón de pérdida de fauna y recuperación del lago Nabugabo demuestra la importancia de refugios para proveer las semillas del resurgimiento y provee un modelo para entender algunos cambios en el Lago Victoria.

Water hyacinth (Eicchornia Crassipes) is a noxious weed that is renowned worldwide for the immediate havoc that it wreaks on waterways, dams, irrigation schemes and water supply intake points; this eventually leads to social, economic and environmental problems for the communities that make their living off of the affected water bodies....

Africa is a continent with a variety of important geographic features that have sculptured its surface giving it an all times scenic beauty as well as providing the continent with the scarce natural resources.
These features have proved to be of much importance that the continent seems lifeless without them! This paper looks at the drainage system together with the few geologic signatures and their importance to the African continent and its aggressively growing population.

During the past eight years of the LVEMP project (Phase I) the various components have been able to collect considerable amounts of data and information. The outputs, however, in the form of the analyses, results, reports and papers, are to a large extent isolated to just cover the activity of the individual component, and much of the findings are of a descriptive nature (e.g. LVEMP 2005). Results therefore become fragmented and analytical output is rarely integrated across disciplinary boundaries. Lack of prioritisation in research has lead to a large output of activities and papers that in some cases duplicates already known work. The research activities have not as yet lead to strategic conclusions on the future focus of research, monitoring, investments and preventive measures, nor has it been translated into a holistic understanding of the ongoing processes or integrated management actions.

This report is a first attempt to systematically compile and consolidate available data – over as long a time frame as possible - into 56 selected indicators. The indicators cover the physical environment, the primary and secondary biological levels, the fish faunal composition, life-histories and abundance, the fishery in terms of yields, effort and catch rates, economics and management. Aquaculture and Database indicators are included as well. Together they represent and illustrate the most comprehensive picture of the present status and the past trends and changes of the Lake Victoria ecosystem and fisheries based on the best available data. Not all indicators are complete, and it is hoped that gaps and missing information can be added in the future. Some indicators are covering the history of the lake over the past 4 decades, while others are based on relatively new research work and only show the latest development. Only when viewed in combination has it been possible to derive an evidence based understanding of the processes that drive the Lake Victoria ecosystem.

This study was meant to generate information on the effectiveness of Beach Management Units on sustainable fishery management on Lake Victoria. The study intended specifically to; assess the status of fishery practices, examine institutional and managerial challenges and suggest mechanisms to make the BMUs sustainable. The study was conducted in the Musoma Rural District’s BMUs. A total of three (3) BMUs (Kigeraetuma, Mugango and Etaro) were involved in the study.
Data were collected by using three main methods; a questionnaire-based survey involving a total of 120 respondents; Key informant interviews with the BMU leaders and fishery officers and Focus Group Discussions, with different groups at each site. After fieldwork data were entered in SPSS version 16.0 and analyzed by using simple descriptive statistics as a uni variate analysis interms of frequencies and percentage.  Data were presented in terms of frequency and percentages. Results have shown that; the status of illegal fishing was moderate to high, this phenomenon, was attributed by income poverty within the studied areas and the high fish demand.  Findings proclaim that, BMUs institutional and managerial performance was poor to very poor, mainly because of lack of the government support and non-enforcement of regulations. However, suggestions were made for the government and other fishery stakeholders to provide relevant training and sensitization, financial support for both BMUs committees and the fishermen to curb the illegal fishing problem as well as a provision of necessary facilities and equipment. The study recommends that, the Government should continue to provide assistance on fisheries development, through appropriate Policy and Legislation in collaboration with Local Authorities, BMUs, fishing communities, Community Based Organization, Non-Government Organizations and the Private Sector, so that the fishery resources of Lake Victoria are sustainable managed, harvested and developed for the benefit of the riparian communities.

1Centre for Water Research, University of Western Australia, Crawley, WA, 6009, Australia 2KARI/LVEMP Coordination Office, Re-Insurance Plaza, 2nd Floor, Kisumu 40100, Kenya 1Email: antenucc@cwr.uwa.edu.au ... Abstract Winam Gulf is a large (surface area ~ ...

The malacofauna of the Nile is poor compared to that of the Congo and its degree of endemicity is lower. While the highest species richness of the Congo Basin is in stenotopic taxa that live in the rivers and lakes, the highest diversity in the Nile Basin occurs in eurytopic taxa living in fringe habitats such as temporary pools. The paucity of endemics that need perennial waters as well in the Lower Nile as in the White Nile confirms the geological evidence indicating instability and discontinuity in water supply during Plio-Pleistocene times. The fauna of the Nile is predominantly Afrotropical in the Lower Nile and exclusively Afrotropical south of the junction of the White Nile and Blue Nile. Of all sub-basins, the degree of endemicity (either zero or two species) is lowest in the Equatorial Nile, indicating that the perennial aquatic environment in this sub-basin is young (probably Holocene) and lending support to the idea that the Bahr el Arab and White Nile Transcontinental Rift System were hydrologically unstable, with endorheic, alkaline lakes during most of the Plio-Pleistocene (Salama, 1997). In the Lower (Egyptian) Nile and in the Ethiopian Highlands palaearctic faunal components occur, consisting of widespread species and of a limited number of endemics of palaearctic origin, related to Levantine species. Most of these taxa first appear in the fossil record around 2.5 Ma. There is no evidence that the Nile functioned as an invasion route for Eurasiatic species prior to that time. Only Theodoxus niloticus is possibly of Paratethyan origin and may have invaded in the Late Miocene. The main invasion of freshwater molluscs into Africa appears to have occurred via the Horn of Africa in Middle and Late Miocene times. In the East African Rift, a diversified fauna occurs that only shares a fraction of species with the Nile Basin north of the Albert Nile (> ~5° N). In the equatorial headwaters, some species from southern Africa reach their northern limit, but the main community consists of species that are either endemic to one of the rift lakes or endemic to the region stretching from Turkana to the Kivu Basins. There hence exists a distinct East African bio-province, that was already recognisable in Pliocene assemblages and that had developed before the present lakes formed in the Late Pleistocene. Concerning the young age of Lake Victoria and the occurrence of an endemic cichlid superflock in the lake, the fossil molluscan record points to a persistence in the East African Rift of freshwater bodies sufficiently extensive to harbour a molluscan community — and ipso facto also fish — during periods of aridity/hyperaridity. The hypothesis of Verheyen et al. (2003, 2004), that the stem lineages of the East African haplochromines, presently inhabiting Lakes Victoria, Kyoga, Rukwa, Albert, George, Edward and surrounding waters, already existed during the Late Pliocene is consistent with the fossil evidence. The location of the area(s) of refuge (around Mount Elgon?) remains hypothetic, however. The fossil records of the Turkana Basin, Tugen Hills and Albertine Basin show that around the Miocene/Pliocene boundary, two distinctive tropical molluscan palaeo-bioprovinces existed in equatorial Africa: an East African and a Congolian province. Regular incursions in both provinces during the Pliocene by elements of a third group, the so-called ‘Nilotic’ community, indicate the presence of a third distinctive Afrotropical palaeo-bioprovince situated more to the north. The molluscan community of the Chad Basin contains the same ‘Nilotic’ species (or closely related forms) as found in the Egyptian and Sudanese Nile but is more diverse, particularly in unionoids. Considering the climatic instability in the region of the different Nile Basins north of ~5° NL, the Neogene Chad-Eosahabi/Palaeosahabi system sensu Griffin (2006) is considered the most likely region of origin of the ‘Nilotic’ malacofauna, while the southern part of the Chad Basin (Chari-Logone system) may have acted as a refuge of this ‘Nilotic’ fauna during arid phases. During Late Pliocene and Pleistocene wet phases the White Nile may have contained a perennial hydrological system, creating opportunities of exchange of aquatic faunas with Chad and the East African Rift System.

The Lake Victoria Basin is home to the most extensive wetlands in Eastern Africa and these wetlands support remarkably high levels of floral biodiversity. Freshwater plants have a diverse range of uses, with variations in use depending on the plant part and life stage. Medicinal use of plants is very common in rural communities, as there is often no access to modern medical facilities, and investigations of the medicinal properties of plants have been conducted for centuries.

Given these attributes, Lake Victoria (and its basin) is uniquely central to curbing problems of both malnutrition and poverty if measures can be put in place to ensure sustainable use of its biodiversity. In this chapter, we provide a summary of our detailed assessment of the use and livelihoods value of the freshwater fishes and plants of the Lake Victoria Basin. The aim of this assessment was to collate information on the many and varied uses of these species, in order to increase awareness of their great importance to the livelihoods of the communities of the Lake Victoria Basin, and demonstrate that conservation of this biodiversity is of vital importance.

Poverty is a pervasive issue in small-scale fisheries. Not only does it affect a substantial population, it is also a complex problem that is difficult to define, explain and solve. Thus, poverty in small-scale fisheries constitutes what in the planning literature is sometimes identified as a ‘wicked problem’. This paper applies the interactive governance framework to identify the limits of, and conditions for, governability and how they affect poverty, using the Lake Victoria small-scale fisheries in Tanzania as an illustrative case. More specifically, the paper first uses the three systems model of the interactive governance framework, i.e., the system-to-be-governed, the governing system, and the governing interaction, to explore poverty as a ‘wicked problem’ involving challenges pertaining to governability. Secondly, the paper suggests ‘governance elements’ that are fundamental for addressing poverty through the first, second, and third orders of governance. The paper emphasizes the importance of social values as crucial entry points in addressing poverty in small-scale fisheries.

A Benthic Index of Biotic Integrity (B-IBI) was developed for the Moiben River. The index assesses effects of human disturbance on the biotic condition of stream macroinvertebrate communities. Eight stations were selected to represent different land use types including forestry, settlement, grassland and mixed farming, practiced at different intensities. A total of 22 metrics were correlated against habitat quality and water quality parameters to determine their interrelationships. Ten metrics were shown to be responsive to changes in water and habitat quality, so could be used to separate sites according to levels of degradation. These were taxa richness (of Ephemeroptera, Plecoptera, Trichoptera and intolerant taxa richness), assemblage composition (percentage Ephemeroptera + Plecoptera + Trichoptera [EPT] individuals, and percentage of individuals in dominant taxa), pollution tolerance (percentage of tolerant individuals) and three functional feeding group metrics (ratio of scraper:filterer individuals, percentage gatherer genera, and percentage predator individuals). We calculated B-IBIs by summing metrics for each site, after transforming them to a discrete 1, 3, 5 scale. Values for the final index correlated well with measures of human influence based on qualitative assessment of habitat quality (Pearson’s r2 = 0.88). This preliminary benthic macroinvertebrate B-IBI shows promise for developing biological standards, which would facilitate long-term monitoring of streams in the upper reaches of Lake Victoria Basin.

Water resources systems are designed and operated on assumption of stationary hydrology. Existence of trends and other changes in the data invalidates this assumption, and detection of the changes in hydrological time series should help us revise the approaches used in assessing, designing and operating our systems. In addition, trend and step change studies help us understand the impact of man’s activities (e.g. urbanisation, deforestation, dam construction, agricultural activities, etc.) on the hydrological cycle. Trends and step changes in the seasonal and annual total rainfall for 20 stations in the Lake Victoria basin were analysed. The seasonal rainfall for any station in a given year was defined in two ways: (1) fixed time period where the rainy seasons were taken as occurring from March–May (long rains) and from October–December (short rains); and (2) variable periods where the rainy seasons were taken as the three consecutive months with maximum total rainfall covering the period of January–June (long rains) and July–December (short rains), to take into account the fact that the onset of rainy seasons within the basin varies from year to year and from one station to the next. For each station, sub datasets were derived covering different periods (all available data at the station, 1941–1980, 1961–1990, 1971–end of each station’s time series). The trends were analysed using the Mann-Kendall method, while the step changes were analysed using the Worsley Likelihood method. The results show that positive trends predominate, with most stations showing trend being located in the northern part of the basin, though this pattern is not conclusive. In all, 17% of the cases have trends, of which 67% are positive. The 1960s represent a significant upward jump in the basin rainfall. Seasonal rainfall analysis shows that the short rains tend to have more trends than the long rains. The impact of the varying month of onset of the rainy season is that the results from analyzing the fixed-period and variable-period time series are rarely the same, meaning the two series have different characteristics. It may be argued that the variable-period time series are more reliable as a basis for analysing trends and step changes, since these time series reflect more closely the actual variability in rainy seasons from one year to the next. The fixed-period analysis would, on the other hand, find more practical use in planning.