Global commodity chains and the development of poor fisherfolk in Uganda

The Ugandan fishery, heavily influenced by the emergence of global markets, is extremely dynamic. In recent years a major export trade, principally in Nile perch fillets from Lake Victoria, has expanded markedly. The growth of this factory based processing industry has had a marked impact on the pre-existing artisanal fishery, which has become increasingly dependent on supplying the export market instead of its traditional local small-scale markets. The industrial fishery developed as a response to the liberalisation of the management of the Ugandan economy and the consequent opening up of the export markets in North America and Europe. The emergence of the export industry has resulted in the creation of a dual structure in the fisheries sector, with the Nile perch catching and processing chain operating to European standards, whilst the artisanal sub-sector still utilises traditional methods. This dual structure is a potential source of disadvantage to the artisanal fishery which has command over fewer financial assets than the export fishery.

Farming a new economically viable fish species: Kisinja (Barbus altianalis)

Kisinja (Barbus altianalis)is an indigenous omnivorous fish, of high economic value in Uganda. It was widely distributed in most lakes and rivers in the country but its stocks were depleted due to overfishing and degradation of its natural habitat. 1t can grow up to a maximum length of 120m and a weight of 15kg in the wild and grows faster, attains larger size than commonly farmed fishes in Uganda, including the Nile tilapia, the African catfish, and mirror carp. Kisinja is a highly valuable table fish with good taste and aroma especially when smoked. Increased production of Kisinja is therefore necessary to meet economic and nutritional benefits of the communities and conservation of the spedes.

The purpose, costs and benefits of fish introductions: with specific reference to the great lakes of Africa

A reduction in native fish stocks and the need to increase fish production for food, recreation, ornamental purposes and to control disease vectors and weeds have often justified and led to introduction of non-native fishes. Some of these introductions have been followed by benefitial and others by undesirable consequences. For instance introduction of the Nile perch Lates niloticus L. and several tilapiine species into lakes Victoria and Kyoga, and the clupeid Limnothrissa miodon into lakes Kariba and Kivu have resulted in increases in the quantity of fish available to the people around them. Predation by Nile perch and competition with introduced tilapiine species in lakes victoria and Kyoga have caused a severe decline and in some cases total disappearance of many of the native fish species.therefore the concern about fish introductions arises

Manual for production of live feed (Moina) for African catfish fry

The African catfish (Clarias gariepinus) is a commercially farmed fish in Uganda, second in importance after the Nile tilapia (Oreochromis niloticus). This catfish has gained rapid popularity in aquaculture because of its faster growth and higher pond yields attaining average weight of over one kg with pond yields as high as 3.0 kg/m2 in six months compared to an average weight of 500g and pond yields of 1.2 kg.m2 for the Nile tilapia

Capture fisheries in Uganda: why Bujagali hydro-power project and ecological monitoring?

Human use of water resow-ces in Uganda has grown and intensified along with population growth and increasing demand to meet the diverse human needs. In the case of Uganda's rivers, the main uses include fisheries, hydropower generation, abstraction for potable water supply, discharge of sewage and navigation. All these uses can disrupt the integrity of the aquatic ecosystem and may affect the survival of the diversity of organisms. In consideration of the need to increase electricity to meet demand, the Bujagali Hydro-power Project (BHPP) and the National Environment Management Authority (NEMA) recognised the importance of safeguards to mitigate impacts of the project. The National Fisheries Resources Research Institute (NaFIRRI) was assigned the role of providing baseline information on the aquatic ecosystem of the Upper Victoria Nile and to follow up the findings with a monitoring framework during construction and post-commissioning phases.

Framework for cage fish culture development in Uganda

This research work involved a review of scientific and technical literature on cage based fish culture technology, and assessment of the natural and socio-economic potential of thiS technology. The research also reviewed secondary data on aquaculture production from the pilot cage culture facilities at Jinja; the requirements of key targeted species for cage based fish production - the Nile tilapia; the feed requirements and implication for management; the physiochemical parameters for optimal performance of fish production in cages; and preliminary production and operational costs of cage fish production.

The evolution of the fishery of Oreochromis niloticus (Pisces : Cichlidae) in Lake Victoria

The Lake Victoria ecosystem has experienced changes associated fishing levels, arise in lake level of the 1960s, fish introductions and human activities in the drainage basin. Following the fish introductions of the 1950s and 1960s, niloticus has become the most abundant and commercially important species among the tilapiines. It appears to be the only species which has managed to co-exist with the Nile perch not only in Lake Victoria but also in Lake Kyoga where the two species were also introduced. There is, however, little published information on the biology and ecology of the species in the habitats. It has therefore been found necessary to initiate studies as have been developed for Lates niloticus, especially as the two species have assumed major role in the lake's fisheries.

A study of Rastrineobola argentea in the Ugandan lakes

Increased stocks of mukene Rastrineobola argentea and the subsequent interest in its fishery on Lake Victoria has been attributed to the poor performance of the endemic fishery as a result of introductions into this lake of foreign fish species Lates niloticus and Oreochromis niloticus. R. argentea now remains the only endemic fish species of economic importance ranking second to the Nile perch in this lake. Despite this importance, biological information on the species and knowledge of its fishery is scanty. Preliminary observations on the species in the Ugandan waters indicate that R. argentea feeds mainly on zooplankton (copepods) during daylight hours. Small quantities of aquatic insect larvae/pupae (chironomids and chaoborids) are also eaten mainly at night. These fishes breed just after the rainy seasons and the young eventually mature at between 43-44 mm standard length. Growth and population parameters show a rate of growth (K) of 0.92 with L of 64.5 mm S.L. Natural mortality (M) is given at 2.371 and total mortality (2) of 3.594. Two mesh size nets 10 and 5 mm are in use in the lake. The smaller mesh size which is more preferred by the artisanal fishermen however tends to capture many immature fishes. There is therefore need for a unified lakewide data collection on the species and its fishery in order to obtain more reliable biological information necessary proper management of this fast developing fishery.

A study of Rastrineobola argentea (Pellegrin), (Pisces : Cyprinidae) and its importance in the fisheries of Lake Kyoga and the northern waters of Lake Victoria

Rastrineobola argentea is the only native fish species which is still abundant in Lakes Victoria and Kyoga, the others being two introduced species; Lates niloticus and Oreochromis niloticus. It forms an important commercial fishery in Lake Victoria and is very important as food of Lates niloticus in both lakes. The depletion of the originally abundant insectivorous and zooplanktivorous hap lochromines due to predation by Lates niloticus appears to have favoured it by reducing potential competitors for food. It now consumes a wide range of invertebrate organisms that originally used to be eaten by different specialised species of haplochromines which include: larvae and pupae of chironomids and chaoborids, copepods and ostracods. Its size in Lake Kyoga (where the Nile perch was introduced earlier) has, however, decreased and is smaller than that in Lake Victoria probably due to high predation pressure. The twin effect of predation and fishing are likely to exert heavy pressure on the species. Research is therefore required to provide information for its management.

The present-day fishery of the Uganda waters of Lake Victoria

The Uganda waters of Lake Victoria comprise an area of 28,500 square kilometres with a shore line of 2,380 kilometres extending from the Uganda/Tanzania border in the west to the Uganda/Kenya border in the east. A large part of the Uganda waters of the lake is less than 60 metres deep, waters deeper than 60 metres being on the eastern side of the lake. Thus the Uganda part of the lake is tilted towards the east. A number of rivers drain into the lake from the north and the River Nile flows out of the lake towards the Mediterranean Sea. The Ssese, Kome, Buvuma and Busoga Islands form a very distinctive feature of the lake. These are perhaps the remaining high hills which survived the drowning of the northern valleys during the formation of the lake. In fact, in T. P. O'Brien's book 'The Prehistoric Uganda Protectorate (1939)', Solmon gives a critical summary of the work on the formation of Lake Victoria and shows that the northern part of the lake has numerous drowned valleys, a feature which provides varying habitats for particular species of fish and which may have an effect on the species composition reflected in the catches in different areas along the northern shore of the lake. It is interesting to note that although Lake Victoria as a whole has a number of rivers draining into it, Halbfass (1923) calculated and found that 76 per cent of the water entering the lake is precipitation on the lake surface.

Notes on growth and feeding of Crocodilus niloticus

The Uganda Fisheries Department had for some time, kept Nile crocodiles in captivity, and had thus collected a considerable amount of data on growth and feeding rates. It had also devised marking and handling techniques, and a system of pens and enclosures to deal with crocodiles up to 3 m. long. The following account describes these techniques and results, which followed a study of a proposed commercial crocodile farm.

Observations on the taxonomy and biology of Lates (Cuvier 1828) in Lake Albert

Both in terms of commercial landings and biological importance, the Nile Perch is one of the most prominent fish in Lake Albert. It can bear considerable further exploitation, is the source of stockings elsewhere, and it is, therefore, important to know whether more than one species is being dealt with, and, if so, what differences there are in the ecology of the different species.

Increase in fish production achieved by stocking exotic species (Lake Kyoga, Uganda)

The Lake Kyoga complex lies towards the north of Uganda, at 311 altitude of 3,400 feet, between 10 and 2° north of the Equator. The lake is extremely elongate and digitate, shallow (1 metre-7 metres), and almost all the coast-line is swampy, with many papyrus beds. Floating islands of sud are a feature. At its eastern extremity, it breaks up into many swampy, isolated lakes. The Nile from its source at Jinja enters Lake Kyoga on its southern side, and leaves the lake at its western extremity, and winds on through to Lake Albert and the Sudan. The Kyoga/Salisbury /Kwania complex covers 2,354 sq. km. of water. Geologically, the lake is a series of flooded river valleys, probably resulting from the uplifting of the western edge of the basin in the Pliocene and the Pleistocene ages aud the endemic fish fauna is very similar to that of Lake Victoria, although Kyoga has not developed the species flocks of haplochromis which characterise the larger lake. The Victoria fauna extends down-stream of Lake Kyoga to the Murchison Falls on the Nile, which forms an almost complete barrier between Kyoga and the typical nilotic fauna of the Nile below Murchison and Lake Albert.

Freshwater medusae in Lake Kyoga

Freshwater medusae have been observed in Lake Kyoga by several members of the Fisheries Department on a few isolated occasions over the past two years. Sightings have been made at Lwampanga at the western end of the lake, at Bukungu near the inlet of the River Nile into Lake Kyoga, and at Lalle, on the eastern extremity of the main lake. Most sightings have been made near the margin of the lake under very calm conditions. At Lalle and Lwampanga large numbers of medusae have been seen swimming near the surface; on these occasions, the medusae were pulsating regularly and maintained a position within a few inches of the surface. Apart from noting that sightings have occurred under calm conditions near the lake margin, no other observations to indicate when medusae are likely to be seen have been made. Most of the medusae are of similar size, the largest being 12 mm in diameter.

East African Freshwater Fisheries Research Organization Annual Report 1970

The Annual report presents activities carried out by the Organization during the reporting period 1970. It explains the scientific work carried out by the Organization which includes: bottom trawl survey, a limnological survey of Lake Victoria for the period January to December 1970, maturity, sex ration and fecundity of lung fish (protopterus aethiopicus Heckel) from Lake Victoria, On the fish species of Lake Baringo, identification of organisms in Lake Victoria responsible for ecosounder traces, further observations on the ecology of the Nile perch (Lates niloticus Linne) in Lake Victoria and Lake Kioga, fishery economics studies, The African journal of Tropical Hydrobiology and fisheries and observation on fish marketing experiments in Tanzania