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ItemRichness and distribution of Benthic Macroinvertebrates in selected waterbodies, Uganda(Makerere University, 2025)Benthic macroinvertebrates are important in the functioning of freshwater ecosystems, as they regulate primary production, cleanse water, decompose organic matter, translocate materials in water, form key links in food webs, and are invaluable indicators of stream degradation. However, most of the biological conservation measures present are for other groups of aquatic organisms, like vertebrates, with limited measures present for macro-invertebrates. Legislative and institutional shortcomings regarding the protection of benthic macroinvertebrates in Uganda pose a severe threat to their protection, for they exacerbate the effects of the primary threats of pollution and habitat loss by failing to provide robust and enforceable mechanisms for their conservation and effective monitoring. The Legislative and institutional shortcomings are due to lack of organized and centralized macroinvertebrate data which hinders evidence-based policymaking and adaptive management. This study aimed at contributing information leading to the development of the first national checklist of benthic macroinvertebrates in Uganda, so as to provide reference baseline information for guiding conservation and sustainable use of aquatic ecosystems in the country. To achieve this, the study mobilized data on occurrence records from datasets available in Global Biodiversity Information Facility (GBIF), archives of biodiversity surveys conducted at the National Fisheries Resources Research Institute (NaFIRRI) in Uganda, and publications of benthic macroinvertebrate studies done in Uganda. A total of 9860 records of benthic macro-invertebrates were retrieved from 65 waterbodies, with 85% of the records from the major lakes namely: Victoria, Kyoga, Albert, George and Edward, and with 15% from the minor/satellite water bodies in the country. This study also revealed that the macroinvertebrates in the country belong to five phyla namely; Annelida, Arthropoda, Mollusca, Nematoda, and Platyhelminthes, with majority of the records belonging to Phylum Arthropoda, and Nematoda and Platyhelminthes having the least records. Also, majority (58%) of the records were identified to Genus level. In terms of diversity, more families were recorded in large waterbodies, with Victoria basin having higher taxa richness. For the records identified to species level, majority of the species with known conservation status were found to be of least concern status hence are not under threat. The study also revealed that the environmental variables that predict maroinvertebrate assemblages in Ugandan water bodies are: DO, SRP, salinity, SRSI, conductivity, SD, Turbidity, Salin, TSS, pH, NO2, Chla, TP, TN, TD, Temperature, and NH4. Regarding hotspots for biodiversity conservation at broader taxonomic levels (phylum and class), extensive systems like the Kibale swamp-river system and Lake Albert exhibited the highest diversity. At family level however, the Bwindi Impenetrable National Park rivers emerged as a unique hotspot with highest of level diversity. Also, the high proportion (58%) of geographically restricted macroinvertebrate families in Uganda indicates that Uganda's waters host many rare macroinvertebrate families. This indicates that they are extremely vulnerable, and those specific waterbodies need immediate protection to ensure these indigenous species survive. Also, the high number of Not Evaluated (NE) species (highest in Lake Victoria) points to significant knowledge gaps in basic taxonomic assessment of benthic macroinvertebrates in the country.
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ItemEffectiveness of salt and propolis combinations in preservation of Brycinus nurse from Lake Albert, Uganda(Makerere University, 2026)Brycinus nurse from Lake Albert takes long period of time from 3-7 days to dry. This compromises its quality, often resulting in its diversion to animal feed rather than human consumption. The study was designed to hasten drying rate and therefore reduce the percentage of B. nurse being channeled to feed production. This study investigated the effectiveness of salt and honeybee propolis (HBP) combinations in preservation of Brycinus nurse (Ruppell, 1832) from Lake Albert, Uganda. In order to achieve this, B. nurse samples were subjected to sixteen (16) different concentrations of salt, propolis, and salt-propolis combinations and sun-drying. During 150 days of storage at room temperature, samples were evaluated every 30 days for sensory, chemical, and microbial characteristics to determine the overall acceptability. The results indicated that, the most effective salt and HBP concentrations for preserving B. nurse were 20% and 15% respectively. B. nurse samples preserved with HBP were rejected earlier than those of salt, indicating that salt is a stronger preservative than HPB. Effective combination of HBP and salt was 20% Salt + 15% HBP for both sensory, microbial and chemical quality as it exhibited higher sustained acceptability scores than the rest of the samples throughout the storage time. However the study found out that 20% salt + 10% HBP, 20% salt + 15% HBP 30% salt + 5% HBP, 30% salt + 10% HBP, and 30% salt + 15% HBP combinations preserved the fish samples for 150 days. It can be concluded that Salt-HBP combination is more effective in preservation of B. nurse compared to salt and HBP. This study provides the first systematic evaluation of salt–HBP combinations for fish preservation in Uganda, demonstrating their synergistic effect in extending shelf life, and enhancing fish marketability. Introducing propolis, a locally available, underutilized natural preservative, this research advances existing knowledge on sustainable fish preservation technologies and offers practical solutions for reducing post-harvest losses and improving livelihoods among fishing communities around Lake Albert. The study recommends using propolis and salt combinations of 20% salt + 15% HBP due to their synergistic effect in maintaining sensory, microbial, chemical properties and its acceptability, marketability and profitability. Key words: Brycinus nurse, Salt, Honeybee propolis, Alestidae
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ItemThe regeneration potential and conservation of excelsa coffee, coffea liberica w. bull var. Dewevrei (de wild. & t. Durand) lebrun, in selected sites of Uganda(Makerere University, 2025)Sustainability of the coffee sector and livelihood of the communities that are dependent on this crop in Uganda will require exploration of nature-based solutions as climate continues to change. This study intended to assess the regeneration potential and conservation of wild excelsa coffee in selected sites of Uganda. The aim was to investigate excelsa coffee natural stock and recruitment capability and its potential for on-farm growing. Five study areas previously known or expected to harbor excelsa coffee were surveyed but, only Zoka Central Forest Reserve and Semuliki National Park had wild excelsa coffee sighted. Forty-seven quadrats of 20 m x 20 m were used for measurement of trees with >10cm diameter at breast height (DBH). In the quadrat were nested smaller ones of 10 m x 10 m, 5 m x 5 m and 2 m x 2 m for measurement of poles, saplings and seedlings respectively. In the same quadrat of 20m x 20 m, all plant species were identified and, unidentified ones collected as vouchers. The stand curves of both Semuliki and Zoka exhibited an Inverse-J curve implying healthy populations of Excelsa coffee that can sustain themselves through natural regeneration. The large number of seedlings dominated over the mature excelsa coffee trees in all study areas. In Ziroobwe farms, an irregular inverted J curve, a fairly good regeneration status was obtained.The number of seedlings was greater than saplings, thus showing a healthy population. The plant species closely associated with excelsa coffee in Zoka CFR were: Cola gigantea, Rinorea dentate, Cordia africana, Argomuellura macrophylla, Coffea canephora and Olyra latifolia. In Semuliki NP, it was associated with Desplatsia dewevrei, Marantochloa purpurea,Celtis mildbraedii Elaeis guineensis and Markhamia lutea plants species. In Ziroobwe Farms, it was associated with; Milicia exclesa, Argeratum conyzoides, Cordia africana, Coffea canephora and Markhamia lutea plants species. Settlement, logging and agriculture were the leading threats to conservation in Zoka Central Forest Reserve and Semuliki National Park. Generally, sustainable regeneration status of excelsa coffee was exhibited in Zoka Central Forest Reserve and Semuliki National Park. In Ziroobwe farms, the pattern was not definite, probably owing to management practices by the farmers who take interest in agronomical aspects such as spacing and how these influence yield. The population of coffee gives a high chance for breeding. Priority should focus on both in situ andex situ conservation strategies.
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ItemEffect of ground salt and crop residue ash filtrate on retention and bioavailability of selected micronutrients in vegetables(Makerere University, 2025)Leafy vegetables form part of the diet of most people in tropical Africa. Different processing and preparation methods are used to prepare a vegetable meal including use of ground salt and crop residue ash filtrates. However, the effect of the use of ground salt and crop residue ash filtrates on the nutrient profile of the leafy vegetables is not well understood. This study examined the effect of use of ground salt, crop residue ash filtrate from simsim and bean husks on the retention of micronutrients, antinutrient factors and mineral bioavailability in the black-eyed pea leaf vegetable, pumpkin leaf vegetable and ‘malakwang’. The micronutrients studied were iron, zinc, calcium, phosphorus and magnesium based on the foundation of their public health importance. Polyphenols, tannins and phytates were the antinutrition factors analyzed because of their ubiquitous nature in vegetables. The vegetables were analyzed for iron, zinc, magnesium, calcium and potassium content using AAS and spectrophotometry for potassium. The antinutrition factors were analyzed using spectrophotometry. The bioavailability of iron and zinc was assessed using in-vitro digestion method. pH of the ground salt and crop residue ash filtrate was measured using a pH meter. The retention of micronutrients was dependent on the quantities of that particular micronutrient in the salt treatment. Retention of iron of 108.8% in ‘boo’ boiled with simsim ash filtrate indicates possibility of supplementation from the salt treatments. Simsim ash filtrate had the highest iron concentration of 5.58mg/g. Highest pH of 10.37 was in simsim ash while ground salt had the lowest at 10.18. The alkaline cooking environment introduced by use of salt treatments was probably responsible for leaching into cooking water, autooxidation, flavonoid acylation, formation of tannin complexes affecting the levels of antinutrition factors. Additionally, polyphenol oxidase being inactivated at alkaline pH had an impact on the levels of polyphenols in these vegetables. Denaturation of fiber in the alkaline cooking water probably explains higher percentage mineral bioavailability in ‘malakwang’ and pumpkin leaf vegetables boiled with the salt treatments. This study provides evidence-based insights into the effect of ground salt and crop residue ash filtrates in vegetables that guide nutrition education efforts towards optimization of the traditional cooking methods in the context of improving dietary quality and combating micronutrient deficiencies.
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ItemBees and their contribution to the yield of robusta coffee and pumpkins in selected districts of central Uganda(Makerere University, 2025)Bees play a vital role in enhancing the yields of flowering crops like Robusta coffee and pumpkins through pollination. This study investigated how cultivation practices influence bee diversity, abundance, and their contribution to the yields of Robusta coffee and pumpkins in the southern Kyoga basin district of Kayunga and central Lake Victoria Crescent districts of Luwero and Nakaseke. The research was conducted between July 2020 and April 2022. The study focused on Robusta coffee grown under shaded and open sun conditions, as well as pumpkin plots located at distances of ≤ 3 km and > 3 km from potential natural or semi-natural bee habitats. Bee diversity and abundance were assessed twice between December 2020 and October 2021 using pan trans and sweep nets across 100 m² plots established on each study site for the respective crops. Pollination exclusion treatments were undertaken to assess the impact of pollination on fruit set and yield. Statistical analysis using one-way ANOVA and logistic regression revealed that shaded Robusta coffee plots and pumpkin plots ≤ 3 km had significantly higher bee diversity, abundance, and crop yield. Hypotrigona sp. and Lasioglossum sp., were more prevalent in shaded conditions. Pumpkin plots ≤ 3 km exhibited higher fruit set, larger fruit mass, and greater seed counts than those > 3 km. In contrast, completely bagged flowers resulted in the complete absence of fruit production, underscoring the absolute dependence of pumpkins on insect pollination. The findings emphasize the critical role of agroforestry systems and the proximity of crops to pollinator habitats in enhancing pollination services and optimizing crop yields and hence the promotion of sustainable agriculture in Uganda.