A report of the gillnet survey in the Ugandan waters of Lake Victoria under IFMP (January to March 2006)

Under the Implementation of the Fisheries Management Plan (IFMP) for Lake Victoria Result area 4, quarterly gillnet surveys are undertaken to monitor changes in fish stocks and environmental parameters in the shallow nontrawlable areas of the lake For purposes of monitoring surveys, the Ugandan sector of Lake Victoria is divided into 3 zones as shown in Figure 1. During the second quarter of APE2, two gillnet surveys were undertaken in zones 1 and 3 in February and March 2006 respectively. The purpose of the surveys was to monitor changes in the fish stocks and their biological characteristics, water quality, algal dynamics and invertebrate communities; as detailed in the various sections of the report. The surveys followed those conducted in November and December 2006 in the same zones. Results of the surveys showed that the number of fish taxa was higher in the near-shore fleets (0-100m) decreasing towards offshore. The near-shore areas were also associated with high primary productivity and hence secondary production to which Caridina and other invertebrates are part. These organisms are an important source of food for the fish and this may partly account for the high number of fish species recorded in this area of the lake. It was also observed that although Nile perch was the most dominant fish species recorded in all the stations during the surveys, haplochromines, Brycinus sadleri, Brycinus jacksonii Oreochromis niloticus and various mormyrid species contributed significantly to the fish biomass. The presence of many fish species and their coexistence with the predator, Nile perch is attributed to the presence of macrophyte cover and rocky habitats which serve as refugia in the shallow inshore habitats of Lake Victoria. In addition, the vegetated habitats are an important source of food for the fishes. As reported in macro-invertebrate studies, big populations of Caridina and other invertebrates were recorded among macrophyte beds. Caridina is an important source of food for juvenile Nile perch and other fish species so are the other invertebrates especially chironomid larvae, odonata nymphs and molluscs. Resurgence in haplochromine cichlids was observed during the surveys. The presence of haplochromines cichlids in all the sites especially Thruston Bay where it ranked the second by percentage contribution in number, is evidence of the recovery of this group of fishes which had declined largely due to predation by L. niloticus. Caridina nilotica has also increased in biomass and is a major component of the Nile perch diet. This could have reduced predation pressure on the haplochromines by Nile perch and has possibly contributed to recent resurgence in haplochromines cichlids in the lake in the shallow nontrawlable areas of the lake Rastrineobola argentea was found to be an important prey item for Nile perch and other fish species such as Clarias gariepinus. Measures should therefore be taken to ensure sustainable harvesting of Dagaa so that there is enough left to sustain the fishery of Nile perch and other species.

A report of the fisheries catch assessment survey in the Ugandan waters of Lake Victoria for the March 2007 survey

This report presents findings of the CAS conducted in the Ugandan waters of Lake Victoria in March 2007. The results of the previous seven CASs conducted under the same programme in July/August/September/November 2005, and March/August/December 2006 are included to show the emerging trends.

Report on the frame survey of Lake Albert conducted in May 2012

Lake Albert and Albert Nile are a major source of fisheries resources sustaining the riparian communities in Uganda and the Democratic Republic of Congo (DRC). Like all shared bodies of Uganda Lake Albert and Albert Nile fisheries are faced with immense exploitation pressure one time described as the tragedy of the commons. In Uganda, the lake is shared by five riparian districts namely: Buliisa, bundibugyo, Hoima, Kibaale and Nebbi. The lake covers a total estimated surface area of 5,270 km2 with approximately 60% within Ugandan waters (Walker, 1972). It is located in the western part of the great rift-valley at an altitude of 618 m above Sea level. The central parts of the lake are characterized by steep escarpments whereas the northern and southern parts lie in a plain of the rift valley. The plains are gently sloping, resulting in shallow swampy inshore waters in many places. The major inflowing rivers are the Semliki and Kafu in the south, and the Victoria Nile at the northern tip. The lake has a diverse fish fauna with a gradient of multi-species fisheries in different parts of the lake.

Report of the baseline survey undertaken on the Chinese cage site in Napoleon Gulf, Northern Lake Victoria, 12 March 2012

The government of the People's Republic of China through a 2007 agreement with the Government of the Republic of Uganda, has establishment of an Agricultural Technology Demonstration Center (ATDC). The first phase covering the building of aquaculture infrastructure at Kajjansi ARDC is complete and the second operation phase has started in which facilities for cage culture have been set up in the Napoleon gulf, northern Lake Victoria near Jinja. The cage facility is aimed at boosting fish farming within the lake as a diversification to the traditional pond fish culture technology. NaFIRRI scientists as well as Chinese experts undertook a baseline survey in the chosen cage site on 12 March 2012. The survey covered determination of water depth, water transparency, measurement of selected physical-chemical parameters (temperature,dissolved oxygen, conductivity and pH; determination of the nutrient status and study of algae, invertebrate and fish communities at the site. Materials and methodologies used in the survey were based on the Standard Operating Procedures (SOPs) of NaFIRRI. The study area was divided into three study sites. Site 1 (upstream) was at 8.9 metre depth while site 2 (proposed cage site) and site 3 (downstream) were 6 and 4.3 metres deep respectively. Water transparency was lowest at site 1 (1.58 m) and highest at site 3 (1.64 m). Dissolved oxygen at the three sites ranged from 6.0 to 8 mg/I. Water temperature profiles fluctuated within narrow limits between 26.5 and 27.5 DC. Measurements of pH were between 7 (neutral) and 8 (alkaline) while electrical conductivity was between 98 and 101 uS/em. These observed physical-chemical parameters at the study site were considered suitable for cage fish rearing purposes. Nitrite-nitrogen levels varied within narrow limits from 0.043 to 0.0453 mgtl. Similarly, Ammonia-nitrogen varied between 0.015 and 0.0185 mg/1. Soluble reactive phosphorus (SRP) level was highest at site 3 (O.012mgll) compared to that at sites 1 and 2 (0.009mgll). Total suspended solids (TSS) were higher at site 1 (83.3mgll), thereafter decreasing to lower levels at sites 2 (24.8mgtl) and 3 (19.8mgl) respectively. The nutrient level results observed here all fall below the maximum permissible limits by NEMA and therefore the site is recommended for cage culture The algal community was constituted by four major groups: Blue greens,Greens, Cryptophytes, and Diatoms with blue greens as the common and dominant group. High algal biomass (19944961 ugtL) of the dominant blue green algae was observed at site 1 compared site 2 and 3 (58655.2 & 27487. 7 ugtL) respectively. Occurrence of toxicin producing algae: microsytis and cylindrospermopsis in the proposed cage area was considered to be of not much significance as their concentrations were below harmful levels. However, monitoring their presence, biomass and seasonality will be critical in order to follow when and where they occur and at what time of the year for ease of management of the cages

A report of the fisheries catch assessment survey in the Ugandan waters of Lake Victoria for the March 2006 survey

This report presents findings of the CAS conducted in the Ugandan waters of Lake Victoria in March 2006. The results of the CASs in July, August, September, and November 2005 are also included to show the emerging trends. The findings indicate stable production of Nile perch and tilapia but large fluctuations in the Mukene fishery. The estimates from the March 2006 data show a monthly catch of 12,360.2 t worth shs12.8 billion of direct gross income to the fishers. Out of this, 36% (4479.4 t) of the catch was Nile perch which was worth shs 9.3 billion (73%) of the direct gross revenue of the fishers. The catches of tilapia contributed 19% of the total catch and 18% of the gross revenue from the catches at the beach. The catches of Mukene, a low value fish, contributed 44% of the weight of the total catches but yielded only 8% of the estimated gross income of fishers.

A report of the fisheries catch assessment survey (CAS) in the Ugandan waters of Lake Victoria for July 2005

This report presents findings of the first CAS in the Ugandan waters following the agreed SOPs, carried out in July 2005. The findings indicate a total fish catch of 15,047.5 t for July 2005, contributed by Mukene/Dagaa (39.5%), Nile perch (33.1%), Tilapias (17.1%), Haplochromines (9.2%) and other fish species 1.2%. This information gives a new perspective of the estimates of fish production in the Ugandan waters of the lake which are based on field observations. Continuation of support to the CAS programme will certainly get rid of the uncertainties about the fish production levels of the lake which have been there for a long time. This information is vital for fisheries development and fisheries management endeavours.

Report on Lake Wamala fisheries catch assessment survey 2012

Lake Wamala is one of the small lakes in Uganda, and lies between latitudes 0o 15; and 0o 25' N 31o 45' to longitude 32o 00' E, longitude and at an altitude of 1000m above sea level. Following ths 1961 heavy rains the lake expanded from about 100 to 118 sq. km and the swamps covered almost 60 sq km (Okaranon 1993). This lake was first stocked with Oreohromis niloticus eduardianus populary known as Oreohromis niloticus then Oreochromis leucostictus and then Tilapia zillii then after that it was officially opened for commercial fishing in 1960. Despite of the commercial fishery there used to be subsistance fishing that was mainly by the use of wires and hooks and targeted the Clarias and Protopterus species. The lake fishery used to be highly profitable after the opening in 1960; though in 1970s the fishers started complaining of the declining state of the fishery. At that time the O. niloticus had gone down to less than 1 kg per net per night by 1975 (Okaranon 1993). Due to it led to scientists undertake fisheries surveys in 1975/78 and later 1988/92 then later on there subsquent survey in 2003. Since that time there has been no work done until March 2012 that both catch assessment and frame surveys undertaken to ensure that management issues are addressed concerning this riparian water body. The main objectives of the survey were:- To assess fish production levels in the commercial fisheries of Lake Wamala (Catch Assessment). To assess the fishing effort and facilities available at the fish landings that supports the fisher folks.

National report of the frame survey 2012 on the Uganda side of Lake Victoria

This is a report on the results of the Frame Survey conducted in the Uganda side of Lake Victoria during August 2012 by the LVFO Institutions, namely: the Department of Fisheries Resources (DFR) Uganda and the National Fisheries Resources Research Institute (NaFIRRI) in close collaboration with the District Fisheries offices of Busia, Bugiri, Namayingo, Mayuge, Jinja, Buvuma, Buikwe, Mukono, Kampala, Wakiso, Mpigi, Kalungu, Masaka, Kalangala and Rakai. In the 2012 Frame survey some indicators of fishing effort including e.g. number of fishers, fishing crafts and long line hooks increased; whereas others like the number of gillnets less than 5 inches decreased by 10.4% from that recorded in 2010. The other indicators of fishing effort, which showed decrease in 2012 included illegal beach seines and undersized gillnets (<5 inch mesh size). However, a large proportion (66%) of long line hooks recorded in the 2012 survey were in the smallest size range (hook size >10), which target small Nile perch. The number of other illegal gears, i.e. cast nets and monofilament gillnets showed modest increases (25%) between 2010 and 2012 while beach seines decrease by 15%. Recent crackdown on illegal fishing activities as part of measures for recovery of the Nile perch stocks which are faced with depletion appear to have had an impact but much more needs to be done to eradicate illegal fishing. The fisheries in the Ugandan waters have remained predominantly near shore with 61% of all fishing crafts using paddles out of which 17% were tiny three plank, flat bottomed boats locally known as parachutes. The 2012 survey shows an increase in the number of fishing crafts using sails by 65% from 682 in 2010 to 1125 in 2012. This is an encouraging trend as more fishers are able to access distant fishing grounds using free wind power. The Mukene fishery in the Ugandan waters of Lake Victoria remained underdeveloped comprising only 15.2% of all fishing crafts, of which 31% were motorised which is a great improvement from the situation recorded in 2010. The Catamarans increased to 18 with a majority in Buikwe district where there is a private investor fishing specifically for Mukene. The Catamarans in Kalangala were reported not to be working because of the high operating cost compared to ordinary Mukene fishing boats.

Report of Lake Wamala fisheries frame survey 2012

Lake Wamala, a small lake (180 km2) located in Central Uganda and believed to have been part of the main Lake Victoria and only got separated about 4000 years ago, has already undergone different levels of fisheries evolution that warrant using it as a case study to inform changes in other systems. Using resources provided by the Lake Victoria Environmental Management Project (LVEMP) II, under the Applied Research Facility, we evaluated the fishing inputs, socio-economic infrastructure and analyzed trends in fishery benefits to guide evolution of management advice. A frame survey was conducted on the entire lake (13th - 23rd March 2012) enumerating all fishing factors and enlisting available and accessible socio-economic infrastructure along the shores of the lake. The lake traverses districts (Gomba, Mityana, and Mubende) with its largest portion lying in Mityana. There are 26 established fish landing sites and about 600 fishers with a similar number of boats on the lake. The total number of boats on the lake is almost equal to the number of fishers; illustrating the common type (paracute) and size (Small, about 4 m) of boats and hence a fishing crew structure of one fisher per boat. Main fishing gears are Gillnets targeting the tilapia (Ngege) and long line hooks (Protperus, Mamba, and Clarias, Male). Almost equal number of boats used the two main gears on the lake (about 300 each). 97% of the gill nets on the lake are small (3.5” (8.9 cm – 4.5” – 11.4 cm) stretched mesh size while 98% of the hoots are large (< size 10). The implication is gill net fishers target small tilapia while long line fishers aim at the large mamba and male. Generally the lake has poor socio-economic infrastructure compared to other lakes of Uganda probably due to its geo-morphological setting. The lakes fishing factors have continued to expand with the ever increasing population. There may be need to check the continued entry into the fisheries especially if the increasing effort does not translate into increase in fishery yield.

Issues of HIV/AIDS/ health among the fisher communities of Lake Albert and Kyoga

The fisheries resources of Lakes Albert and Kyoga present a high potential for economic growth, food, employment and foreign earnings. However, livelihoods appear to be compromised with the emergence and rapid spread of HIV/AIDS in the fisher communities of L. Albert and Kyoga. HIV/AIDS is considered a silent epidemic that is unique, posing a great challenge to the fisheries managers, health service providers, development planners and the resource users themselves. Fishers have high HIV prevalence, as well as AIDS-related illnesses and mortality rates. The high HIV prevalence rates among the fishing communities in Uganda is between 10-40% compared to the national rates which lie between 6% and 7%. This indicates that the national programmes have not adequately addressed the plight of the fishing communities of Lakes Albert, and Kyoga and the consequences have been devastating. Men and women living in fishing villages across the world have been found to be between five and ten times more vulnerable to the disease than other communities (Tarzan et al 2005, FAO, 2007). The present prevalence rates among the fishing communities stands at 10 to 40 % (LVFO, 2008). Meanwhile the same fishing communities are the essential labour for the Lakes’ fishery industry which is thriving nationally and internationally. That resource potentially can alleviate poverty and the HIV/AIDS threat. Fishing communities are the hidden victims of the disease, mixing patterns with the general population could act as a reservoir of infection that could spill over into the general population to drive the epidemic. On L. Albert, a quarter of the fisher folk were HIV-positive by 1992 compared to 4% in a nearby Agricultural village. Since then, there have been no targeted studies to address or monitor the prevalence rates eight years later, yet the multiplicity factor is high. HIV/AIDS can be linked to unsustainable fisheries, as the labour force available would not go to deep waters to fish, instead would fish in the shallow waters as a coping mechanism. A further effect is the loss to National and local economies and reduced nutritional security for the wider population. HIV/AIDS remains a significant challenge that has created a mosaic of complexity in the fishery sector. This needs to be addressed. It is, therefore, paramount that a comprehensive study was under taken to address this pandemic and the phenomenon of HIV/AIDS based on the study objectives. 1. To determine the trend in HIV/AIDS infection among fishing communities and the factors affecting it 2. To assess the impacts of HIV/AIDS on fish production and the implications for fisheries management.

Final report of the fisheries catch assessment survey in the Ugandan waters of Lake Victoria for the March 2010 survey

This report presents findings of the CAS conducted in the Ugandan waters of Lake Victoria in March 2010. The results of the previous ten CASs conducted under the same programme in July, August, September and November 2005; in March, August and December 2006; in March, and August 2007; in February and December 2008 are included to show the emerging trends. The report also presents total annual catch estimates for the Ugandan part of the lake from 2005 to 2010.

An instance of cyclonic upwelling in the southern offshore waters of Lake Victoria

Evidence is presented that cyclonic upwelling took place in the southern offshore waters of Lake Victoria on the 22nd to the 23rd March, 1969. Before this, the main upper thermocline was tilted downwards in the leeward northern half of the lake in response to the accumulation of epilimnetic water. Cyclonic upwelling might be quite common because of the frequent occurrence of storms on Lake Victoria, and probably on other tropical African lakes. However, to my knowledge, it has never been reported from any lake.

Chemical, microbiological and sensory examinations of dried Lake Tanganyika sardine presently marketed in Zambia

Proximate composition, PH, total aerabic counts, coliform counts, appearance and taste of dried Lake Tanganyika sardine (Limnothrissa miodon and Stolothrissa tanganicae) sampled at Lusaka markets were analysed for the period July 1969 to February 1970. Water content for the dried sardine varied between 7 and l4% and oil content between 8 and 14% according to season. Flavour of the cooked sardine was scored as good to fair, which discredits the common belief that is poor in quality. Cooked fish scores correlated poorly to the oil content and bacterial counts of the dried fish.

The feeding of three commercially important fish species in Lake Chilwa, Malawi

The diets of the three species of fish that predominate in the Lake Chilwa fishery are described in relation to various parameters using a semi-quantitative method of analysis of the digestive tract contents. Barbus paludinosus Peters fed during the day on zooplankton, non-filamentous green algae and some higher plant material; small fish fcd predominately on zooplankton but with increasiug size the diet was more varied. Clarias mossambicus Peters fed throughout the day and night and had a highly varied diet with fish becoming the major food item in large fish, Tilapia shirana chilwae Trewawas fed mainly during the day on higher plant material, filamentous green algae and zooplankton; smaller fish fed predominately on zooplankton. The importance of flexibility in the diet of the three fish species is stressed.