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Abstract Background The tigerfish (Hydrocynus forskahlii) is an important food fish in different regions of Africa. As such, interest in its performance and nutritional requirements as a potential candidate for aquaculture is increasing. Characterization of the morpho-histological features and functions of the gut provides valuable insights into the feeding physiology and digestive system of fish species. Result An investigation of the morpho-histological features of the gastrointestinal tract of H. forskahlii captured from Lake Albert was conducted over an eight-month period. The digestive tract of H. forskahlii is characterised by a short oesophagus, well-developed and distensible stomach and moderately long intestine. The oesophagus had a higher abundance of mucous-secreting goblet cells compared to other digestive tract tissues. The stomach had a bag-like shape for swallowing large prey and was distinguishable into the cardiac, fundic and pyloric regions. Both the cardiac and fundic regions of the stomach had numerous gastric glands, whereas the pyloric region had large compound folds consisting of pseudo-stratified columnar epithelium. Many goblet cells were also observed in the mid and posterior regions of the intestine. The relative length of the gut of the H. forskahlii was 1.27 ± 0.03 cm, and it had a total of 20–22 pyloric caeca. The liver was observed to be divided in lobules by a central vein contained within connective sheets. Irregular cords of hepatocytes were also visible throughout the parenchyma. Conclusions The histological features of the H. forskahlii gut observed in the present study are consistent with those of carnivorous and omnivorous fish.

Background: The tigerfish (Hydrocynus forskahlii) is an important food fish in different regions of Africa. As such, interest in its performance and nutritional requirements as a potential candidate for aquaculture is increasing. Characterization of the morpho-histological features and functions of the gut provides valuable insights into the feeding physiology and digestive system of fish species. Result: An investigation of the morpho-histological features of the gastrointestinal tract of H. forskahlii captured from Lake Albert was conducted over an eight-month period. The digestive tract of H. forskahlii is characterised by a short oesophagus, well-developed and distensible stomach and moderately long intestine. The oesophagus had a higher abundance of mucous-secreting goblet cells compared to other digestive tract tissues. The stomach had a bag-like shape for swallowing large prey and was distinguishable into the cardiac, fundic and pyloric regions. Both the cardiac and fundic regions of the stomach had numerous gastric glands, whereas the pyloric region had large compound folds consisting of pseudo-stratified columnar epithelium. Many goblet cells were also observed in the mid and posterior regions of the intestine. The relative length of the gut of the H. forskahlii was 1.27 ± 0.03 cm, and it had a total of 20–22 pyloric caeca. The liver was observed to be divided in lobules by a central vein contained within connective sheets. Irregular cords of hepatocytes were also visible throughout the parenchyma. Conclusions: The histological features of the H. forskahlii gut observed in the present study are consistent with those of carnivorous and omnivorous fish. [ABSTRACT FROM AUTHOR]

Abstract Background Urogenital schistosomiasis caused by the parasitic blood fluke Schistosoma haematobium is the most common form of that constitutes a majority of over 240 million schistosomiasis cases. The enigmatic absence of urogenital schistosomiasis in Uganda has, until now, been attributed to the absence of substantial populations of suitable snail intermediate hosts. Methods Malacological surveys were carried out in 73 sites southeast of Lake Albert, Uganda in October and November 2020. Collected snails were transported to the laboratory for identification. The snails were identified using partial mitochondrial cytochrome c oxidase subunit one and nuclear internal transcribed spacer barcoding. Schistosome infections in snails were also assessed using cercarial shedding and rapid diagnostic PCR techniques. Results We found Bulinus globosus and Bulinus nasutus productus, the main intermediate species in the transmission of S. haematobium in mainland East Africa. In this survey, B. globosus was more common than B. nasutus productus, with the former reported at four sites (total count = 188) and the latter reported at one site (total count = 79). Molecular testing revealed a high prevalence of Schistosoma bovis in B. nasutus productus (16%), but no S. haematobium infections were found. Conclusions Given the abundance of snail hosts and the risky human water contact behaviours observed, we highlight the potential for urogenital schistosomiasis transmission in the region. Graphical Abstract

Background: Urogenital schistosomiasis caused by the parasitic blood fluke Schistosoma haematobium is the most common form of that constitutes a majority of over 240 million schistosomiasis cases. The enigmatic absence of urogenital schistosomiasis in Uganda has, until now, been attributed to the absence of substantial populations of suitable snail intermediate hosts. Methods: Malacological surveys were carried out in 73 sites southeast of Lake Albert, Uganda in October and November 2020. Collected snails were transported to the laboratory for identification. The snails were identified using partial mitochondrial cytochrome c oxidase subunit one and nuclear internal transcribed spacer barcoding. Schistosome infections in snails were also assessed using cercarial shedding and rapid diagnostic PCR techniques. Results: We found Bulinus globosus and Bulinus nasutus productus, the main intermediate species in the transmission of S. haematobium in mainland East Africa. In this survey, B. globosus was more common than B. nasutus productus, with the former reported at four sites (total count = 188) and the latter reported at one site (total count = 79). Molecular testing revealed a high prevalence of Schistosoma bovis in B. nasutus productus (16%), but no S. haematobium infections were found. Conclusions: Given the abundance of snail hosts and the risky human water contact behaviours observed, we highlight the potential for urogenital schistosomiasis transmission in the region. [ABSTRACT FROM AUTHOR]

Abstract Introduction Schistosomiasis poses a serious public health problem and a social challenge affecting over 240 million people, the majority of whom live in sub-Saharan Africa. The World Health Organization (WHO) recommends praziquantel (PZQ) drug treatment through regular mass drug administration (MDA) accompanied by social mobilisation and health education and sensitisation. With social mobilisation and health education and sensitisation, there is bound to be increased demand for the PZQ, especially in the case of endemic communities. However, it is not clear where communities go for PZQ treatment in the absence of PZQ MDA. We explored the health-seeking behaviours regarding schistosomiasis treatment among communities along Lake Albert in Western Uganda when MDA had delayed, to inform a review of the implementation policy for the achievement of the WHO’s 2030 target of 75% coverage and uptake. Methods and materials We conducted a community-based qualitative study in Kagadi and Ntoroko, an endemic community in January and February 2020. We interviewed 12 individuals: local leaders, village health teams, and health workers, and conducted 28 focus group discussion sessions with 251 purposively selected community members. The audio recordings of the data were transcribed and analyzed using a thematic analysis model. Results Generally, participants seldom seek medication for schistosomiasis-related signs and symptoms from government hospitals and health centres II, III and IV. Instead, they rely on community volunteers such as VHTs, private facilities, such as clinics and drug shops nearby, or traditional sources (e.g. witch doctors and herbalists). Results show that factors influencing people to seek treatment from sources other than the government are: the absence of PZQ drugs in the government health facility; health workers’ negative attitude towards patients; long distances to the government hospitals and health facilities; poor and inaccessible roads; medication-related costs; and negative perceptions of the PZQ drug. Conclusions Availability and accessibility of PZQ seem to be a big challenge. PZQ uptake is further hampered by health systems and community-related and socio-cultural factors. Thus there is a need to bring schistosomiasis drug treatment and services closer to endemic communities, stock nearby facilities with PZQ and encourage endemic communities to take the drug. Contextualised awareness-raising campaigns are needed to debunk myths and misconceptions surrounding the drug.

Introduction: Schistosomiasis poses a serious public health problem and a social challenge affecting over 240 million people, the majority of whom live in sub-Saharan Africa. The World Health Organization (WHO) recommends praziquantel (PZQ) drug treatment through regular mass drug administration (MDA) accompanied by social mobilisation and health education and sensitisation. With social mobilisation and health education and sensitisation, there is bound to be increased demand for the PZQ, especially in the case of endemic communities. However, it is not clear where communities go for PZQ treatment in the absence of PZQ MDA. We explored the health-seeking behaviours regarding schistosomiasis treatment among communities along Lake Albert in Western Uganda when MDA had delayed, to inform a review of the implementation policy for the achievement of the WHO's 2030 target of 75% coverage and uptake. Methods and materials: We conducted a community-based qualitative study in Kagadi and Ntoroko, an endemic community in January and February 2020. We interviewed 12 individuals: local leaders, village health teams, and health workers, and conducted 28 focus group discussion sessions with 251 purposively selected community members. The audio recordings of the data were transcribed and analyzed using a thematic analysis model. Results: Generally, participants seldom seek medication for schistosomiasis-related signs and symptoms from government hospitals and health centres II, III and IV. Instead, they rely on community volunteers such as VHTs, private facilities, such as clinics and drug shops nearby, or traditional sources (e.g. witch doctors and herbalists). Results show that factors influencing people to seek treatment from sources other than the government are: the absence of PZQ drugs in the government health facility; health workers' negative attitude towards patients; long distances to the government hospitals and health facilities; poor and inaccessible roads; medication-related costs; and negative perceptions of the PZQ drug. Conclusions: Availability and accessibility of PZQ seem to be a big challenge. PZQ uptake is further hampered by health systems and community-related and socio-cultural factors. Thus there is a need to bring schistosomiasis drug treatment and services closer to endemic communities, stock nearby facilities with PZQ and encourage endemic communities to take the drug. Contextualised awareness-raising campaigns are needed to debunk myths and misconceptions surrounding the drug. [ABSTRACT FROM AUTHOR]

[Display omitted] • We studied the diversification of monogenean gill parasite Dolicirroplectanum lacustre infecting introduced Nile perch. • Parasite co-introduction led to reduced morphological and genetic diversity in Lake Victoria. • High morphological diversity in Lake Albert indicates a phenotypic plasticity of D. lacustre. • Intraspecific diversification in D. lacustre was demonstrated by the presence of two morphotypes. • Mitonuclear discordance indicates an incomplete reproductive barrier between the morphotypes. The Nile perch (Lates niloticus) is a notorious invasive species. The introductions of Nile perch into several lakes and rivers in the Lake Victoria region led to the impoverishment of trophic food webs, particularly well documented in Lake Victoria. Additionally, its parasites were co-introduced, including Dolicirroplectanum lacustre (Monogenea, Diplectanidae). Dolicirroplectanum lacustre is the single monogenean gill parasite of latid fishes (Lates spp.) inhabiting several major African freshwater systems. We examined the intra-specific diversification of D. lacustre from Lates niloticus in Lake Albert, Uganda (native range) and Lake Victoria (introduced range) by assessing morphological and genetic differentiation, and microhabitat preference. We expected reduced morphological and genetic diversity for D. lacustre in Lake Victoria compared with Lake Albert, as a result of the historical introductions. We found that D. lacustre displayed high morphological variability within and between African freshwaters, with two morphotypes identified, as in former studies. The single shared morphotype between Lake Albert and Lake Victoria displayed similar levels of haplotype and nucleotide diversity between the lakes. Mitonuclear discordance within the morphotypes of D. lacustre indicates an incomplete reproductive barrier between the morphotypes. The diversification in the mitochondrial gene portion is directly linked with the morphotypes, while the nuclear gene portions indicate conspecificity. Based on our results, we reported reduced genetic and morphological diversity, potentially being a result of a founder effect in Lake Victoria. [ABSTRACT FROM AUTHOR]

Trematodiases strongly reduce the welfare of humans and animals causing a great decline in health and productivity. Insufficient data on the extent of trematode infection in definitive hosts and associated risk factors remain a great threat to its control. A cross-sectional study was conducted to establish the; prevalence of liver flukes and schistosomes in livestock and wild mammals and the socio-ecological risk factors associated with their spread. Fresh dung samples were collected opportunistically (n = 865) and examined using formal ether sedimentation and microscopy for parasite eggs. Twelve abattoir visits were conducted to examine the livers of animals killed for mature flukes. Key informants (n = 110) including farmers, butchers, game rangers, and herders were interviewed to document the socio-ecological risk factors. In the abattoirs, 57.1%(CI 0.422-0.712) of cattle were infected with Fasciola flukes and not sheep and goats. Cattle dung had the highest prevalence (56% CI 0.518-0.604) of Fasciola eggs, followed by sheep (50%, CI 0.319-0.681) and goats (28.2%, CI 0.218-0.353). Among wild mammals, hippos' dung (66%; 95% CI 0.53-0.777) had the highest prevalence of Fasciola followed by warthogs (8%; 95% CI 0.002-0.385) and baboons (6.7%; CI 0.002-0.319). No Fasciola eggs were observed in elephant dung (n = 21) and monkeys (n = 2). Schistosoma bovis was found in cattle dung from Mpeefu (2.6%; 95% CI 0.007-0.066) and Ndaiga (4.3%; 95% CI 0.022-0.075) while S. mattheei in goats' (1.4%; 95% CI 0.00-0.075) and cattle (0.39%; 95% CI 0.00-0.021) dung samples from Ndaiga. Key informants had moderate knowledge of fasciolosis (62.7%), highest among butchers (89.7%), and lowest among herders (31.8%). Only veterinary officers knew about schistosomiasis in animals. Free-range grazing and unsafe water sources for livestock, shared with wild animals, were the risky practices by most farmers (66-100%). Fasciola was prevalent in livestock and wild mammals, while Schistosoma in cattle and goats., Competing Interests: No conflict of interest., (© 2024 The Authors.)

Schistosomiasis is a tropical parasitic disease affecting more than 200 million people worldwide, predominantly in Africa. The World Health Organization recently highlighted the importance of targeted control of the freshwater snails acting as intermediate hosts for the parasites causing schistosomiasis. However, because of a shortage of trained experts and resources, detailed information on spatiotemporal snail distributions, which is needed for targeted control measures, is often missing. We explore the potential of citizen science to build these much-needed datasets through fine-grained, frequent snail sampling. We trained a network of 25 citizen scientists to weekly report on snail host abundances in 77 predefined water contact sites in and around Lake Albert (western Uganda). Snail abundance, together with marked GPS locations, water chemistry parameters, and photographs of the identified snails are recorded and submitted using the freely available mobile phone application KoBoToolbox. Trained researchers then engage in remote, semi-automatic validation of the submissions, after which there is an opportunity to provide targeted feedback to the citizen scientists. Five months after the operationalisation of the network, a total of 570 reports were submitted and personalized feedback was given, resulting in lasting improvements in subsequent reporting and snail genus identification. The preliminary results show the possibility of citizen science to independently obtain reliable data on the presence of schistosome snail hosts. We therefore argue that citizen-driven monitoring on a high spatiotemporal resolution could help to generate the much-needed data to support local targeted snail control measures in remote and/or resource-limited environments.

Schistosomiasis is a tropical parasitic disease affecting more than 200 million people worldwide, predominantly in Africa. The World Health Organization recently highlighted the importance of targeted control of the freshwater snails acting as intermediate hosts for the parasites causing schistosomiasis. However, because of a shortage of trained experts and resources, detailed information on spatiotemporal snail distributions, which is needed for targeted control measures, is often missing. We explore the potential of citizen science to build these much-needed datasets through fine-grained, frequent snail sampling. We trained a network of 25 citizen scientists to weekly report on snail host abundances in 77 predefined water contact sites in and around Lake Albert (western Uganda). Snail abundance, together with marked GPS locations, water chemistry parameters, and photographs of the identified snails are recorded and submitted using the freely available mobile phone application KoBoToolbox. Trained researchers then engage in remote, semi-automatic validation of the submissions, after which there is an opportunity to provide targeted feedback to the citizen scientists. Five months after the operationalisation of the network, a total of 570 reports were submitted and personalized feedback was given, resulting in lasting improvements in subsequent reporting and snail genus identification. The preliminary results show the possibility of citizen science to independently obtain reliable data on the presence of schistosome snail hosts. We therefore argue that citizen-driven monitoring on a high spatiotemporal resolution could help to generate the much-needed data to support local targeted snail control measures in remote and/or resource-limited environments. [ABSTRACT FROM AUTHOR]

A new product in the form of edible fish powder was developed from small pelagic fish (Brycinus nurse) which constitutes one of the major commercial fisheries in Lake Albert, Uganda. The objective of the study was to determine the proximate and mineral composition of the newly developed fish powder and also to compare it with Nile tilapia powder already on market. Results indicated that the changes in the amount of protein and ash were found to be significantly higher (p < 0.05) in fish powder than in fried samples. The increase in fat content of fried fish samples was found to be significant compared to other fish samples. No significant changes (p > 0.05) were observed in carbohydrate content for raw, fried, and powdered samples. Vitamin A decreased significantly in powdered samples. Comparing the B. nurse powder and tilapia powder (made from juvenile tilapia as raw material), the results indicated that B. nurse had higher levels of iron and manganese. Extracting proteins from B. nurse provides an opportunity to increase the utilization of harvested catch. Brycinus nurse, Fish powder, Lake Albert, Pelagic fish [ABSTRACT FROM AUTHOR]

Abstract: Drought significantly shifts the mix of functional groups present in river ecosystems and abundances of many aquatic fauna decline. The consequences of drought for fish often include the decline of ecological specialists and the predominance of generalist species. However, factors influencing the restructuring of littoral fish assemblages following prolonged drought in heavily regulated rivers are poorly understood. We compared the restructuring of littoral fish assemblages in 2 large connected lakes, which differ in hydrology and habitat availability, after 15 years of drought in their catchment. The once‐abundant and diverse fish assemblages showed limited signs of postdrought recovery after 5 years. There were differences between the 2 lakes related to the species present, their abundances, and the functional groups within fish assemblages. The functional groups present also shifted through time from alien‐dominated to freshwater generalist‐dominated. Only 2 of 5 native fish functional groups (freshwater generalist and diadromous) had increasing abundances (used as a proxy for recovery) following the drought, and these increases only occurred in the lake with the greater connectivity and diversity in habitat and hydrology. In contrast to patterns observed for natives, abundances of alien fishes in the littoral zone of the lakes declined after an initial spike in numbers associated with substantial river flows immediately following drought. This study shows that the recovery of native fish populations following prolonged drought in a heavily regulated semiarid river occurs over a time scale of years and recovery of some extant ecological specialists was incomplete after as many as 5 years. [ABSTRACT FROM AUTHOR]

The early Pliocene fan delta complex developed in the south of Lake Albert Basin which is located at the northern end of the western branch in the East African Rift System. The stratigraphy of this succession is composed of distributary channels, overbank, mouthbar and lacustrine shales. Limited by the poor seismic quality and few wells, it is full of challenge to delineate the distribution area and patterns of reservoir sands. Sedimentary forward simulation and basin analogue were applied to analyze the spatial distribution of facies configuration and then a conceptual sedimentary model was constructed by combining with core, heavy mineral and palynology evidences. A 3D geological model of a 120 m thick stratigraphic succession was built using well logs and seismic surfaces based on the established sedimentary model. The facies modeling followed a hierarchical object-based approach conditioned to multiple trend constraints like channel intensity, channel azimuth and channel width. Lacustrine shales were modeled as background facies and then in turn eroded by distribute channels, overbank and mouthbar respectively. At the same time a body facies parameter was created to indicate the connectivity of the reservoir sands. The resultant 3D facies distributions showed that the distributary channels flowed from east bounding fault to west flank and overbank was adhered to the fringe of channels while mouthbar located at the end of channels. Furthermore, porosity and permeability were modeled using sequential Gaussian simulation (SGS) honoring core observations and petrophysical interpretation results. Despite the poor seismic is not supported to give enough information for fan delta sand distribution, creating a truly representative 3D geomodel is still able to be achieved. This paper highlights the integration of various data and comprehensive steps of building a consistent representative 3D geocellular fan delta model used for numeral simulation studies and field development plan. [ABSTRACT FROM AUTHOR]

Micronutrient deficiencies and food insecurity constitute major threats to human health across Africa. With decreasing availability of large-bodied fishes (>20 cm), strategies have developed to target small pelagic fish (SPF) species (<20 cm total length) to improve the food availability; yet little is known regarding their nutritional content. Three species of SPFs - Engraulicypris bredoi (muziri), Brycinus nurse (ragoogi) and Rastrineobola argentea (mukene) - were collected from lakes Albert, Victoria, and Nabugabo in Uganda, East Africa. The content of essential elements (Ca, Fe, K, Mg, Na, P, Se, and Zn) and non-essential, potentially toxic elements (Cd and Pb) were measured and compared in fishes across landing sites within lakes Victoria (R. argentea) and Albert (B. nurse, E. bredoi) and between lakes (R. argentea). Rastrineobola argentea was the most nutritious of the fishes examined, although some variation was present in their elemental concentration among landing sites. Overall, all three species contain high levels of essential nutrients and fall within a safe range for non-essential, toxic elements based on current consumption habits. These SPFs can play an important role in addressing nutritional deficiencies in Uganda, and effort should be made to increase the availability, accessibility, and consumption of these under-utilized small fishes. • Quantification of the content of elements in small fishes in Uganda. • Species analyzed provide high levels of vital elements (Ca, Fe, Zn). • Some differences are apparent in elemental concentrations within and between lakes. • Species analyzed are low in non-essential elements (Cd, Pb). • Nutritional value of species is highly relevant for human health and food security in East Africa. [ABSTRACT FROM AUTHOR]

The Holocene turbidite systems of Lake Kivu and the Pliocene turbidite systems of Lake Albert in the East African Rift were examined using high-resolution 2-D and 3-D seismic reflection data and sediment core information. Based on investigations of seismic facies and lithofacies, several key turbidity-flow depositional elements were observed, including channels, overbank levees with sediment waves, and depositional lobes. Analyses of the sources of the recent and ancient turbidite systems in these two extensional basins suggest that flood-induced hyperpycnal flows are important triggers of turbidity currents in lacustrine rift basins. From source to sink, sediment dispersal, facies distribution, and depositional thickness of the turbidite systems are strongly influenced by rift topography. The Lake Kivu and Lake Albert rifts serve as excellent analogues for understanding the sedimentary patterns of lacustrine turbidites in extensional basins. [ABSTRACT FROM AUTHOR]

Abstract: New biomarker analyses from Lake Albert, East Africa spanning ~15–9ka show the most extreme, abrupt, multi-stage climate and environmental shifts during the last deglacial transition of anywhere in Africa. Records of hydroclimate expressed in compound specific δD values from terrestrial leaf waxes and a TEX86 paleotemperature record support multiple stages of pronounced drying and cooling from 13.8 to 11.5ka and demonstrate the dynamic behavior of the low latitude tropics during the deglaciation. The vegetation response, illustrated by compound specific δ13C values and fossil pollen records, was an expansion of C4 grassland when the region was cool and arid. These results advance our understanding of a spatially and temporally complex regional response to global climate forcing, suggesting weakening of the Indian Ocean monsoon at the end of the Pleistocene that coincides with a minor decrease in the rate of the Atlantic Meridional Overturning Circulation (AMOC) and during a time of stepwise cooling in the northern high latitudes. [Copyright &y& Elsevier]

Abstract: In order to investigate the capacity of being intermediate host for Schistosoma mansoni, the Ugandan F1 generation of Biomphalaria snail species that were laboratory-bred from parent populations originally collected from either Lake Victoria or Lake Albert was challenged with sympatric and non-sympatric S. mansoni isolates. After a prepatent period of 20 days, a daily 10-hourly snail shedding for cercariae was done to determine the infection rate, cercarial production per hour and survival period of infected snails. The study suggests that when parasite strains from a different geographical origin is used for infection, survival of infected snails increase, leading to an increased transmission potential. Although earlier literature had indicated that the Lake Victoria Biomphalaria sudanica is refractory to S. mansoni, we showed that all Ugandan Biomphalaria spp., including B. sudanica from all locations, were highly susceptible to the S. mansoni isolates. Thus if B. choanomphala, which is an efficient intermediate host in Lake Victoria, is given an opportunity to occupy Lake Albert, it will most likely be compatible with the Albertine S. mansoni parasites. Equally, if B. stanleyi, currently restricted to Lake Albert invades Lake Victoria, it is likely to act as an efficient intermediate host. Future work should concentrate on intraspecific population-level differences in compatibility. [Copyright &y& Elsevier]

The article presents a study that used mitochondrial DNA sequence variations to characterize the snail populations of the Bulinus truncatus/tropicus complex sampled in Lake Albert in western Uganda. Included in the study were 39 snail samples collected from five populations, Booma, Bugoigo, Piida, Toonya, and Walukuba. Based on analysis of patterns of sequence variations and evolutionary relationships within localities using a 612 basis point (bp) fragment of the mitochondrial cytochrome oxidase subunit gene, the authors discovered five unique haplotypes defined by 21 polymorphic sites.

Lakes and reservoirs (impoundments) are often viewed as a sink for nutrients within the river continuum. To date, most studies on nutrient retention within impoundments are derived from the temperate climate zones of Europe and North America, only consider one nutrient, and are often short-term (1–2 years). Here, we present a long-term (17 year) data set and nutrient (nitrogen, phosphorus and silica) budget for two connected semi-arid lakes (the Lower Lakes) at the terminus of the River Murray, Australia. Most of the filterable reactive phosphorus and nitrate entering the lakes were retained (77 and 92%, respectively). Total phosphorus (TP) was also strongly retained (55% of the annual TP load on average) and the annual TP retention rates could be predicted as a function of the areal hydraulic loading rate (annual lake outflow/lake surface area). On average, there was a slight net retention (7%) of the annual total nitrogen (TN) load but a slight net export (6% of the load) of organic N. TN retention as function of the areal hydraulic loading rate was lower than expected from existing models, possibly because of high nitrogen fixation rates in the Lower Lakes. Silica was retained (39%) at similar rates to those observed in previous studies. There was also a marked increase in the TN:TP and TN:Si ratios within the lake (TN:TP~30 and TN:Si~0.67) compared to those entering (TN:TP~15, TN:Si~0.45), as a consequence of the relatively low net retention of nitrogen. [ABSTRACT FROM AUTHOR]

The three known sympatric Biomphalaria species that occur in Lake Albert; B. choanomphala, B. stanleyi and B. sudanica, were studied using both molecular (COI, 16S and ITS) and shell morphometric data. An unidentified sample of 18 Biomphalaria specimens from Lake Albert were divided in three morphotypes according to aperture height and coiling rate and subsequently identified through molecular inferences and morphometry. The 18 specimens were identified as follows; six specimens were identified as B. sudanica, seven species as B. stanleyi, four as B. cf. choanomphala and a single specimen as B. pfeifferi. The latter was inferred with strong molecular support only, since it had similar shell morphology to typical B. stanleyi snails, thus it might be an ecophenotypic form of B. pfeifferi adapted to a lacustrine environment. Biomphalaria stanleyi exists in forms that resemble B. choanomphala, and B. choanomphala has further overlap in morphology with B. smithi. However, the results showed some disagreement between molecular and morphometric identification, hence making it difficult to rely on shell morphology alone in identification. Overall the morphometric analysis divided Biomphalaria in two possible ecophenotypes i.e. a lacustrine type with rapidly increasing whorls and relatively high apertures and a non-lacustrine type (including snails inhabiting lake edges) with slowly increasing whorls and low apertures. [ABSTRACT FROM AUTHOR]

Fish consumption in subsistence fishing community is a life style associated with lead and mercury uptake for humans. Fish consumption is influenced by sociocultural factors, exposure and health risks. Unfortunately, no sociocultural study in the Lake Albert fishing community in light of lead and mercury exists. A cross-sectional sociocultural study was carried out between March and June 2015. A total of 270 household heads in four landing sites in Hoima district completed structured questionnaires and data analyzed using SPSS version 20. The majority of the households (74.8%) had primary education or below, 51.1% drank unboiled water, and 30% perceived lake water safe for drinking. Children under five ate soup (15%) and middle piece of the fish (29%). The Poisson general linear model predicting weekly fish consumption amounts against sociocultural factors showed that household size ( p  = 0.047), male child presence ( p  = 0.007), methods of preparation i.e. salting ( p  < 0.0001), fish parts consumed by adults ( p  < 0.0001), fish preference ( p  < 0.0001), awareness about the beach management unit ( p  < 0.0001), and income from charcoal selling ( p  < 0.0001) were positive predictors. The negative predictors of weekly fish consumption amounts were awareness about fish consumption benefits ( p  < 0.0001), eating young fish ( p  = 0.002), donor agency presence ( p  < 0.0001), and frying as the method of fish preparation ( p  = 0.002). In conclusion, knowledge of the sociocultural factors associated with fish consumption determines the amounts and frequency of the predominant fish eaten. Therefore, to establish and adopt fish consumption guidelines for lead and mercury in the Lake Albert, the sociocultural factors should be integrated in the message disseminated.