Reverine fish studies

Rivers and streams play an important role in the biology of many cichlid and non-cichlid fishes. Some of these species are purely riverine while others are anadromous (potamodromous?). Reverine fish investigations therefore are broad and mainly ecological studies on riverine and lake aspects in the life histories of those fishes concerned

The fish stocks in Uganda aquatic systems: opportunities and challenges for transformation

The status of fish stocks in a water body at any one time is a function of several factors affecting the production of fish in that water body. These include: total number (abundance) and biomass(weight) present, growth (size and age), recruitment (the quantity of fish entering the fishery) including reproduction, mortality which is caused by fishing or natural causes, Other indirect factors of major importance to the status of the stocks include production factors (water quality and availability of natural food for fish), the life history parameters of the different species making up the stocks (e.g. sex ratios, condition of the fish, reproductive potential (i.e. fecundity) etc), Changes in fish stocks do occur when any of the above listed factors directly influence aspects of growth, reproduction and mortality and therefore, numbers and standing stock (biomass). In the exploited fisheries, major research concerns regarding stocks relate to the listed factors especially: estimates of stock abundance/biomass, the quantity of fish being caught,where the fish are caught, which species are caught (relative abundance)when the fish are caught, how the fish are caught. The balance between stock abundance and amount of fish caught provides the basis for intervention. Due to the diverse characteristics of the physical water environment, fishes are in general, not evenly distributed throughout a water body. Shallow and vegetated areas tend to support higher abundance and diversity of fish species. In addition, seasonal variations in fish abundance are so strong that fluctuations in catch have to be expected at fish landings

Promotion of fish farming for poverty alleviation and protein food supplies: a presentation to SPEED

Annual fish harvested from production systems (lakes and rivers) in Uganda is about 300,000 mt. Fish production from aquaculture contributes about 0.02% (i.e. less than 100mt) of total fish production. Fish is currently one of the two most important agricultural export commodities from Uganda with factory-processed fish (mostly Nile perch) exported mainly to Europe, South East Asia and the Middle East worth at least USD 100 m annually. Regional fish exports to Kenya, Tanzania, Rwanda, Sudan, DR Congo and some parts of Central Africa are also important contributing about USD 20m annually. All recorded fish exports rely heavily (95%) on factory-processed Nile perch with the Nile tilapia increasingly entering the export market chain. Regional fish exports are more diversified in terms of species and include Nile tilapia, Nile perch, "mukene", Tiger fish and "Angara", the last two fished from Lake Albert

The water hyacinth problem and the biological control option in the highland lake region of the upper Nile basin: Uganda's experience

The rapid proliferation and extensive spread of water hyacinth Eichhornia crassipes (Mart) Solms in the highland lakes of the Nile Basin within less than 15 years of introduction into the basin in the 1980s pauses potential environmental and social economic menace if the noxious weed is not controlled soon. The water weed has spread all round Lake Victoria and, in Uganda where infes tation is mos t severe, water hyacinth estimated at 1,330,000 ton smothers over 2,000 ha of the lakeshore (August,1994). Lake Kyoga which already constantly supplies River Nile with the weed is infested with over 570 ha, while over 80% of the river course in Uganda is fringed on either side with an average width of about 5m of water hyacinth. As the impact of infestation with water hyacinth on water quality and availability, transportation by water, fishing activities, fisheries ecology, hydro-power generation etc becomes clear in Uganda, serious discussion is under way on how to control and manage the noxious weed. This paper pauses some of the questions being asked regarding the possible application of mechanical and chemical means to control the water weed.Uganda has already initiated the use of biological control of water hyacinth on Lake Kyoga with a strategy to use two weevils namely Neochetinabruchi and Neochetina eichhorniae. The strategy to build capacity and infrastructure for mass multiplication and deployment of biological control of the weevils in the field developed in Uganda by the Fisheries Research Insti tu te (FIRI) and the Namulonge Agricultural and Animal production Research Insti tute (NAARI) is proposed in outline for evaluation. Plans to deploy this strategy on lake Kyoga are under wa

Fisheries research in Uganda

Evolution of fisheries research and FIRRI The earliest approach to fisheries research in Uganda dates from the first fisheries survey of Lake Victoria by Michael Graham between 1927 and 1928 (Graham, 1929). Based on references to the rich fisheries that were reported to Graham, it appears that during the 18th Century, catch per net per night averaged 300 tilapia, a revelation that led Graham to conclude that Lake Victoria is a tilapia lake. The "tilapia" later came to be known as Tilapia esculenta and T variabilis (Oreochromis esculentus and O. variabilis) respectively

The history of fish communities, biodiversity and environment of Lake Victoria and the lessons learnt

The first fishery survey of Lake Victoria was conducted between 1927 and 1928 (Graham 1929). Atthat time, the lake had a diverse fish fauna and the fishery was dominated by two endemic tilapiine cichlids; Oreochromis esculentus (Graham 1929) and O. variabilis (Boulenger 1906). There were a number of other species such as Protopterus aethiopicus Heckel 1851, Bagrus docmac (Forsk.) 1775, Clarias gariepinus (Burchell), Barbus species, mormyrids, Synodontis spp, Schilbe intermedius (Linn.) 1762 and Rastrineobola argentea Pellegrin, 1904 that were also abundant in the lake most of which made a significant contribution to the fishery (Graham 1929, Worthington 1929, 1932, Kudhongania & Cordone 1974). Haplochromine cichlids were represented by at least 300 species more than 99% of them endemic (Greenwood, 1974; Witte et al., 1992 a & b). The fishery of Lake Victoria was similar to that of lakes Kyoga and Nabugabo (Worthington 1929; Trewavas 1933; Greenwood 1965, 1966; Beadle 1962, 1981). There were also important fisheries on the inflowing rivers of Lake Victoria, the most important of which were Labeo victorianus and Barbus altianalis (Cadwallader 1965). The small sized species notably Rastrineobola argentea and haplochromines cichlids were not originally commercially exploited

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

The Fishes and Fisheries of the Victoria Nile

Rivers have formed nuclei for human civilization from the origin of mankind. They provide drinking and irrigation water, supply fish , serve as human and industrial waste depositories, and help in transport from one point to another. In East Africa, riverine ecosystems are recognised more as sources of food (fish) and water than any other use. Fish in Uganda is the cheapest source of (and accounts for 50%) animal protein supply (Bugeny

Smallholder dairy farmer characteristics and their relationships with type of breeds kept in Uganda

Smallholder dairy farming is increasingly becoming an important source of livelihoods for farmers in Lake Victoria agro-ecological Zones (LVZ) in Uganda. This study was carried out in 3 major milk producing regions in Uganda. The main objective was to establish relationships between household characteristics with type of dairy breeds (technology) and also identify the factors that influence choice of a given dairy breed technology. Data came from 236 dairy producing households obtained from a secondary data set of the Uganda National Household Survey (UNHS) for year 2009. The data generated were analyzed using both descriptive statistics (ANOVA tests and chi-square tests) and a multinomial logistic model. The results revealed that out of the 236 studied households 166 had local dairy cows, 58 had improved dairy cows and 12 mixed breeds (both local and improved). The average milk yield was significantly different across households by type of dairy breed. The highest average milk yield was observed among households keeping improved dairy breeds (4.1l/day), 3.5l/day for households keeping mixed breeds and those keeping local had the lowest average milk yield (2.1l/day). The multinomial logistic model further revealed that the choice of improved dairy breeds for milk production over local dairy cows was significantly influenced by access to veterinary services, bicycle ownership and being located in the south western region at 1% level, education and age of the household head at 5% level, ownership of a motorcycle and market access at 10% level. Adoption of mixed breeds over local breeds is strongly influenced by household size, market access and farmer being located in the south western region at 5% level. The study evidently indicated the need to promote improved cows and local cows alongside improved cows (mixed) for sustainable dairy subsector development through extending veterinary services and training of dairy households especially among elderly household heads to adopt better dairy management practices. Keywords: Smallholder farmers; dairy technology; multinomial logistic, choice of breeds

Evolution of the tilapia fishery with specific reference to the Nile tilapia (Oreochromis niloticus Linne)

As a fishery, the immensely large (c. 68,800 km2 ) Lake Victoria is a unique ecosystem which together with a riverine connection to the Lake Kyoga basin share a common endemic "Victorian" fish fauna (Greenwood 1966). Until the 1950s, the single socio economically most important species of fish in these two lakes was the native Oreochromis esculentus Graham (Graham 1929) even though the lake also contained a second native tilapiine, 0reochromis variabilis , and over 300 other fish species (Beauchamp, 1956)