National Agricultural Research Organisation. Fisheries Resources Research Institute Annual Report 2004/2005

About 18% of Uganda’s surface area is covered with water from which about 300,000 metric tonnes of fish are produced. Fish are currently the second most important export commodity generating approximately US$100 million annually. Fish provides 50% of protein diet for the 20 million people translating into per capita consumption of 12 kg. Close to the production system, this figure rises to 50 – 100 kg. It is estimated that fishery-related activities employ at least one million people countrywide (i.e. 5% of the population). Fish exports to regional markets are worth at least US $ 20 million annually. Fish flesh contains an anticholesterol which assists in reducing heart diseases. Some fishes are of medicinal value e.g. haplochromines (Nkejje) are used to treat measles. Most of the fish in Uganda is got from lakes Victoria, Kyoga, Albert and Albert Nile, Edward and George production systems as well as from the 160 minor lakes and rivers and the associated wetland systems. Capture fisheries based in these systems contribute up to 99% of the fish production in Uganda but aquaculture is also picking up. The fishing industry employs up to one million Ugandans

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.

The biology, ecology and impact of the Nile perch, Lates niloticus in lakes Victoria, Kyoga and Nabugabo and the future of the fisheries

Nile perch (Mputa), Lates niloticus was introduced into Lakes Victoria and Kyoga from lake Albert to increase fish production of these lakes by feeding on and converting the small sized haplochromines (Nkejje) which were abundant in these lakes into a larger table fish. It was, however, feared that Nile perch would prey on and deplete stocks of the native fishes and affect fish species diversity. Nile perch became well established and is currently among the three most important commercial species. It is presently the most important export fish commodity from Uganda. Considerable changes have taken place in fishery yield, and in life history characteristics of the Nile perch itself since the predator got established in Lakes Victoria and Kyoga.

Study of effect Rosmarinus officinalis oil and nisin on the growth of Streptococcus iniae in lab conditions and fillets of rainbow trout (Oncorhynchus mykiss)

Fish are an important part of a healthy diet since they contain high quality protein, but typically present a low fat percent when compared to other meats. Fish is an extremely perishable food commodity. On the other hand, food borne diseases are still a major problem in the world, even in well-developed countries. The increasing incidence of food borne diseases coupled with the resultant social and economic implications means there is a constant striving to produce safer food and to develop new antimicrobial agents concerns over the safety of some chemical preservatives and negative consumer reactions to preservatives they perceive as chemical and artificial, have prompted on increased interest in more ‘‘naturalgreen’’ alternatives for the maintenance or extension of product shelf-life. Particular interest has focused on the potential applications of plant essential oils. However, to establish the usefulness of natural antimicrobial preservatives, they must be evaluated alone and in combination with other preservation factors to determine whether there are synergistic effects and multiple hurdles can be devised. In this study, were evaluated the effects of different concentrations of Rosmarinus officinalis and nisin and storage time (15 days) on growth of Streptococcus iniae GQ850377 in a lab conditions and a food model system (fillets of rainbow trout) in 4 and 8 °C. In addition, we also studied multi factorial effects of four different concentration of rosemary, three different concentrations of nisin, two different levels of pH in 3 temperature 4,15 and 37 °C on log% of S.iniae during 43 days in BHI broth. The results on growth of S. iniae were evaluated using SPSS 20.0 statistical software and analyzed the logarithm of total count of the bacterial by Tukey Test. Results were considered statistically significant when P<0.05. MIC and MBC values of rosemary and nisin were 0.03, 0.075 % and 5, 40 μg/mL, respectively. The growth of S. iniae was effected significantly (P<0.05) by rosemary and nisin and also combination of rosemary and nisin in 4 and 8 °C. Samples treated with 0.135 and 0.405 % of rosemary showed a significant decrease on the growth of the bacteria compared with control sample(P<0.05). The most ١٤٦ inhibitory effects were seen in samples treated with 0.135 and 0.405% of rosemary until 9 days after storage. Also, the synergism effects of rosemary and nisin on the growth rate of bacteria was significant (P<0.05) compared with untreated samples and samples treated with the rosemary or nisin, only. Synergistic effects was observed at concentration of 0.405% rosemary and 0.75 μg/mL nisin in both temprature. Results of this study showed that different concentration of rosemary a significant inhibitory effect (P<0.05) on log% of S. iniae, in BHI broth in pH 5.5 and 7 in 4,15 and 37 °C during 43 days. In concentration of 0% rosemary (control) in pH 5.5 and 7 and 37°C, log% were 1.099 and 3.15, whereas in concentration of 0.015% rosemary were -4/241 and 1.454, respectively. The use of essential oils may improve food safety and overall microbial quality. If essential oils were to be more widely applied as antibacterials in foods, the organoleptic impact would be important. In addition, it is recommended to apply essential oils or their compounds as part of a hurdle system and to use it as an antimicrobial component along with other preservation techniques. Thus essential of R. officinalis with high antibacterial activity selected in this study could be a potential source for inhibitory substances against some food-borne pathogens and they may be candidates for using in foods or food-processing systems.

Chemical, bacteriological and sensory examination of split, dried, smoked bream on the market in Zambia

A critical examination of the market quality of split, dried and smoked bream (Tilapia spp.) was chemically, bacteriologically and organoleptically conducted for the period of August 1968 to January 1969. The aim of this survey was to obtain basic information for the development of national quality standards for the commodity. Relationships of cooked meat score to pH, fish size, appearance and smell score, and water content wcre significantly correlated and responsive. Therefore, these parameters were proposed to be used as indices for the quality standards of the products.