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 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.

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.

Report of the catch assessment survey: fishery survey of Kyoga Lakes August 1990 - March 1991

This report presents the information obtained during catch assessment surveys made by the ADP Fishery Survey of Lake Kyoga and Lake Kwania between August 1990 and July 1991. It supersedes previous interim reports on these surveys. The Kyoga lakes had not been surveyed in a long time. Information on the state of the stocks was largely confined conclusions drawn from data collected along the southern shore of L.Kyoga proper. The effect of harmful/illegal gear types on the stocks was not documented. Part I provides a description of the survey. Part II comprises a review of the fishing strategies. Parts III and IV present the principal results obtained on L.Kyoga and L.Kwania. Part V presents a discussion of the main conclusions.