A baseline fish survey and water quality assessment of Butiaba-Wanseko area on Lake Albert

This report gives the baseline information specifically on water quality (physical/chemical, nutrient and phytoplankton biomass status) of the open part of the lake, a river flowing into the lake and a lagoon, within Butiaba-Wanseko area. Oil and gas exploration in the Albertine Graben are on-going activities by Tullow Oil Plc, and Heritage Oil and Gas (Heritage). Part of the activities involve 2-D TZ seismic surveys in exploration area Block 2 (Butiaba-Wanseko area) in Buliisa District. A study of the transition zone (basically along the shoreline was undertaken by National Fisheries Resources Research Institute (NaFIRRI) on behalf of Environmental Assessment Consult Ltd (EACL) during September 2007. A major objective of the study was to carry out a baseline survey of the fisheries and water quality of the lake shore between Wanseko and Butiaba prior to the proposed 2-D Seisimic investigation.

Migration of fishermen and its impacts on fisheries management on Lake Victoria, Uganda

The purpose of the study was to investigate migratory movements of fishermen on lake victoria.To identify the cuases of fishrmen migration with a view to establishing the paterns of migration;determining season of migration and assessing the impacts of migration on fisheries management and development.

Social and economic implications of the fishery distribution patterns on Lake Victoria, Uganda

The fisheries of Lake Victoria have undergonea dramatic transformation during the last two decades. From being a locally based fishery with little intervention and capital investment from outside,the present fishery is dominated by national and international capital penetrating the industry. It is explosion in the growth of nile perch and the strong demand devloped for this fishin the global markets, which have transformed the fisheries of the Lake victoria. This report presents the results of a survey carried out between October 2001 and February 2002 about the fishery distribution patterns and their impacts on fisher communities of Lake Victoria. The fisheries distribution pattern of the lake is described as well as the flows and benefits from the fisheries resource and the resource constraints and sustainability options. A major part of the paper discusses some of the socio-economic impacts of the rapid changes that are responsible for the present fisheries. It particularly focuses on the effect of the Nile perch boom, its globalization and the development of the fish industry in Uganda, on food security and employment for the local population.

A report on frame and catch assessment surveys on Nabugabo lakes, north west, Lake Victoria Basin, Uganda

The Nabugabo lakes are an important source of affordable protein food in the form of fish, income, water for domestic and commercial purposes (aquaculture farm and Hotels), handcraft materials (mats, hats, roof thatch) and fishing floats and rafts. Nabugabo lakes provide employment, income and export earnings to Uganda that flow from the act of harvesting the fish. In Uganda the fisheries sector directly employs 350,000 people and indirectly 1.2 million people. In 2005, it is estimated that about 370,000 mt fish export (97-98% Nile perch) earned Uganda US $ 143 Million up from US $ 103 million in 2004 .and up from US $ 45 million in 1996. , making it almost become the first non' traditional export commodity. The Nabugabo lakes are also import for cultural values and fish species from these lakes are important in evolutionary studies. The fishery sector is therefore very important in Uganda's socio-economic life. Despite the above values to the communities and global biodiversity roles, the amount of fish caught and the number fishing fleets operating on the Nabugabo lakes to guide management of the lake are lacking. The fishery that exists in these lakes is largely for subsistence and commercial purposes specific for Lake Nabugabo based on introduced species (Nile perch and Nile Tilapia). The fish is caught using mainly gill nets and long line hooks.

Management of the nile perch, Lates niloticus, fishery in Lake Victoria in light of the changes in its life history characteristics

Nile perch, Lates niloticus Linnaeus, 1758, is a predatory fish of high commercial and recreational value. It can grow to a length of 2 m and a weight of 200 kg. In Uganda, Nile perch was originally found only in Lake Albert and the River Nile below Murchison Falls. The species is, however, widely distributed in Africa, occurring in the Nile system below Murchison Falls, the Congo, Niger, Volta, Senegal and in Lakes Chad and Turkana (Greenwood 1966).

Priorities for research and management on Lake Victoria

Under the worrisomely changing situation in fish species diversity, water environment characteristics, socio-economic dimensions and other ecosystems variables in Lake Victoria, there is an urgent need to put in place effective research and management packages aimed at safe guarding the sustainability of the vast resources of the lake. Priority in have been out-lined to develop strategies which would promote biological productivity and diversity, and socio-economic returns. But given the size of the lake (69,000 km2) and the complexity of dynamic forces which are driving the changes, coordinated approach for research and management among the riparian states and the international scientific community will be required. The task is not only extensive but urgent as well.

Geographic and economic setting of Lake Victoria

Lake Victoria, besides being the second largest in the world after Lake Superior, is the largest tropical lake. Its waters are shared by Kenya (6% of the surface area), Uganda (43%), and Tanzania (51%). Before dramatic structural and functional changes manifested in the lake's ecosystem especially in the 1980s, fish life flourished in the lake's entire water column at all times of the year. Currently, the situation is much more different from what it was in the past. The exponential increase in the introduced Nile perch (Lates niloticus) and Nile tilapia (Oreochromis niloticus) stocks, siltation, wetland degradation and eutrophication have characterised the lake ecosystem. The two exotic species and the small native cyprinid (Rastrineobola argentea) form the basis of the commercial fishery that was once dominated by two native tilapiines (Oreochromis esculentus and Oreochromis variabilis) and five other large-bodied endemic fishes. Severe deoxygenation observed at shallow depths (Ochumba 1990; Hecky et al., 1994) indicates that a large volume of the lake is unable to sustain fish life. The Lake Victoria catchment is one of the most densely populated areas in East Africa, encompassing a population of about 30 million people. Widespread poverty resulting from high inflation rates, lack of opportunities and general unemployment have characterised the lakeside communities over much of the last two decades. The biophysical environment in which Lake Victoria exists makes the lake particularly susceptible to changes that occur as a result of human modification to the watershed or the lake itself, thus rendering benefits from the lake unsustainable.

The nutritional status of fishing and non-fishing communities of Lake Victoria basin

We examined socio-economic variables that contribute to malnutrition in selected communities in the Lake Victoria basin during 2001. The study was carried out in nine districts and hinterland communities up to 25 km awayfrom the beach were used as the reference population. The main variables examined were: feeding habits, income and intra-household food distribution and living standards. Others included disease and health, sanitation and hygiene, childcare and mothers' age and workload, weaning practices, agricultural production and food availability, care during pregnancy and food taboos.

Distribution of endangered native fish fauna and their conservation in Lake Victoria

Lake Victoria in East Africa, supports socio-economically important fisheries for more than 30 million inhabitants in the lake basin. The lake had until the 1970's a diverse fish assemblage dominated by haplochromines species which formed at least 83% of the fish biomass (Kudhongania & Cordone 1974). The more than 500 haplochromine species in Lake Victoria, over 99% of them endemic, exploited virtually all the food sources in the lake (Witte and van Oijen 1990). Each species had its own unique combination of food and habitat preference (Goldschmidt et al., 1990).

Nutrient status and thermal stratification in Lake Victoria

Worldwide, human activity in the watershed has been found to induce lake responses at various levels, including at population and ecosystem scale. Recently, Carignan and Steedman (2000) reported on disruptions of biogeochemical cycles in temperate lakes following watershed deforestation and lor wildfire and Carignan et al., (2000 a, b) concluded that water quality and aquatic biota are strongly influenced by disturbances in the watershed. Similarly, Lake Victoria is no exception as people in its catchment have exploited it for the last hundred years or more, but have now begun to understand the extent to which they have thrown the lake into disorder and how their increasing activity in the watershed have driven some environmental changes within and around the lake.

Wetlands and riparian zones as buffers and critical habitats for biotic communities in Lake Victoria

Despite their ecological and socio-economic importance, Lake Victoria's adjoining "swamps" and lake interface are among the least investigated parts of the lake. The "swamps" a term commonly equated to "wastelands" and the difficult working environment they present in comparison to open water, are major factors for the low level of attention accorded to shoreline wetlands. Moreover, definitions of wetlands highlighted for example in the Ramsar Convention as "areas of marsh, fern, peatland or water, whether natural or artificial, permanent or temporary, with water that is static or flowing, fresh or brackish, or salt, including areas of marine water, the depth of which does not exceed six metres" (Ramsar, 1971) were designed to protect birds (water fowl) of international importance. The Ramsar definition, which also includes oceans, has till recently been of limited use for Lake Victoria, because itdoes not fully recognise wetlands in relation to other public concerns such as water quality, biodiversity and the tisheries that are of higher socioeconomic priority than waterfowl. Prior to 1992, fishery research on Lake Victoria included studies of inshore shallow habitats of the lake without specific reference to distance or the type of vegetation at the shore. Results of these studies also conveniently relied heavily on trawl and gill net data from the 5-10 m depth zones as the defining boundary of shallow inshore habitats. In Lake Victoria, such a depth range can be at least one kilometre from the lake interface and by the 10m depth contour, habitats are in the sub-littoral range. Findings from these studies could thus not be used to make direct inferences on the then assumed importance of Lake Victoria wetlands in general.

Effects of cage fish culture on water quality and selected biological communities in northern Lake Victoria, Uganda

Growing of fish in cages is currently practiced in Uganda and was first introduced in northern Lake Victoria in 2010. An environment monitoring study was undertaken at Source of the Nile, a private cage fish farm, in Napoleon gulf, northern Lake Victoria. In-situ measurements of key environmental (temperature, dissolved oxygen, pH and conductivity) and biological (algae, zooplankton, macro-benthos) variables were made at three transects: Transect 1- the site with fish cages (WC); transect 2- upstream of the fish cages (USC-control) and Transect 3- downstream of the cages (DSC). Upstream and Downstream sites were located approximately 1.0 km from the fish cages. Environment parameters varied spatially and temporally but were generally within safe ranges for freshwater habitats. Higher concentrations of SRP (0.015-0.112 Mg/L) occurred at USC during February, September and at DSC in November; NO2-N (0.217- 0.042 mg/L) at USC and DSC in February and November; NH4-N (0.0054- 0.065 Mg/L) at WC and DSC in February, May and November. Algal bio-volumes were significantly higher at WC (F (2,780)=4.619; P=0.010). Zooplankton species numbers were consistently lower at WC with a significant difference compared to the control site (P=0.032). Macro-benthos abundance was consistently higher at the site with cages where mollusks and low-oxygen and pollution-tolerant chironomids were the dominant group. Higher algal biomass, concentration of low-oxygen/pollution-tolerant macro-benthos and depressed zooplankton diversity at WC suggested impacts from the fish cages on aquatic biota.

The decline of Alestes baremose Boulenger, 1901 and Hydrocynus forskahlii (Cuvier, 1819) stocks in Lake Albert: implications for sustainable management of their fisheries

The fish stocks of Lake Albert face immense exploitation pressure which has led to “fishingdown” of their fisheries, with some larger species having been driven to near-extinction, while others such as Citharinus citharus have almost disappeared. Both A. baremose (Angara) and H. forskahlii (Ngassia) historically formed the most important commercial species in Lake Albert until the early 2000s but recent Catch Assessment Surveys (2007-2013) revealed a sweeping decline in their contribution to the commercial catch from 72.7% in 1971 to less than 6% in 2013. The catch per unit effort also registered a two-fold decline from 45.6 and 36.1 kg/boat/day to 22.6 and 18.1 kg/boat/day for A. baremose and H. forskahlii respective between 1971 and 2007. Over 50% of illegal gillnets, below the legal minimum limit of four inches (101.6 mm) used on Lake Albert target the two species. Gillnet experiments found the three inch (76.2 mm) gill net mesh size suitable for sustained harvest of the two species. The study concludes that optimal utilization of the two species and probably other non target fish species is achievable through species specific management strategies, coupling species specific licensing, and controlling harvest of juvenile individuals, overall fishing effort and fish catch on Lake Albert and protecting the vulnerable fish habitats.

Characterization of genetic biodiversity of Nile perch, Lates niloticus, Tilapiines, Haplochromine flock and Ningu (Labeo victorianus) in the Victoria Lake Basin: an overview

Genetic biodiversity is the vaflatlOn among individuals within and between units of interbreeding individuals (populations) of a species. It includes inheritable and transmittable differences that occur between individuals andlor popuhitions of a given species through reproductive interaction. There exists enormous variability among individuals andlor populations of a species for most living organisms, and most of this variation is inheritable. differences among individuals arise through mutation and via recombination of genes during meiosis. These ifferences are then transmitted to successive generations through sexual reproduction and maintained in the populations through processes such as natural selection and genetic drift. Unfortunately much of this variation is normally threatened and often in danger of extinction because most focus in conservation of natural resources is put at saving species or habitats than varieties or strains of a species