African Great Lakes Research Articles

Elemental composition of small pelagic fishes in three East African lakes: Implications for nutritional security

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.

Strategizing research and development investments in climate change adaptation for root, tuber and banana crops in the African Great Lakes Region: A spatial prioritisation and targeting framework

CONTEXTGiven the significance of climate change impacts on farming communities, large investments are made by research and development actors, including farmers themselves, to adapt agricultural systems. A data-driven approach is required to guide these investments and maximize their impact. In the African Great Lakes Region (GLR), root, tuber and banana (RT&B) crops are a vital component of smallholder farming systems, but little is known about strategies to mitigate climate change impacts on these crops. OBJECTIVEThe objective of this study was to develop a spatial prioritisation and targeting framework based on the risk of climate-related impacts to guide research investments and prioritisation in CSA for RT&B crops in the GLR. METHODSClimate change impact data on crop suitability were layered onto other spatially-explicit biophysical and socio-economic data to map clusters of homologous regions, called socio-agroeocological homologues (SAHs). The SAHs were defined by the risk of climate-related impacts, resulting from the interaction of hazards, exposure and vulnerability. The framework was applied to RT&B crops (banana, potato, cassava and sweetpotato) in the African GLR. Its utility was illustrated by elaborating adaptation scenarios for selected SAHs of one long-duration (banana) and one short-duration (potato) RT&B crop. RESULTS AND CONCLUSIONFour SAHs were identified for banana, potato and sweetpotato and five for cassava. For each crop, SAHs were prioritised for investment in climate change adaptation based on the level of risk of climate-related impacts. Scenario analysis showed that the introduction of drought-tolerant varieties would increase suitability for banana from 0.30 to 0.47 under baseline conditions and from 0.54 to 0.71 under future climates in a prioritised SAH with low to moderate suitability for typical varieties. For potato, the introduction of heat-tolerant genotypes, intercropping with legumes or the combination of both would allow compensating negative impacts of climate change on crop suitability in two SAHs representing important mid-altitude potato growing areas, from an average of −0.19 and −0.16 to an average of up to +0.25 and + 0.15 respectively. Scaling approaches should consider the difference in socio-economic conditions between the two SAHs. SIGNIFICANCEWe envision the framework to be useful for a diverse range of users throughout the innovation and scaling continuum to understand where climate change impacts are expected to be most severe, what type of innovations are needed to help farmers adapt, and how these innovations should be scaled to enable uptake by considering socio-economic drivers of adoption.

Prevalence of Autotrophy in Non-humic African Lakes

Heterotrophic respiration of organic matter (OM) is thought to dominate over aquatic primary production (PP) in most freshwater lake ecosystems. This paradigm implies that lateral transport of OM from the terrestrial biosphere subsidize the major fraction of aquatic respiration and that many lakes are a net source of carbon dioxide (CO2) to atmosphere. Nevertheless, African lakes were absent of the datasets upon which this paradigm was built. Here, we report a comprehensive and methodologically consistent data set of pelagic PP and community respiration (CR) obtained over the last decade in contrasting non-humic African lakes including 5 of the East African Great lakes (Tanganyika, Kivu, Edward, Albert, Victoria) and smaller shallow lakes located in Eastern Africa. Also, we determined the partial pressure of CO2 in surface waters and examined the sources and dynamics of organic and inorganic carbon by means of stable isotope tools across a wide range of physical and chemical conditions and productivity status. Our observations revealed that the threshold value at which the equivalence between PP and CR is met is substantially lower in Africa (10 mmol C m−3 d−1) than at higher latitude (25 mmol C m−3 d−1), suggesting that non-humic African lakes tend to be more autotrophic than expected from empirical relationships derived from data collected in boreal and temperate regions. Integrated at the regional scale, we estimate that PP is about 20 times higher than the organic carbon burial in sediments. It implies that a large fraction (< 90%) of PP is effectively recycled in the warm water column of non-humic African lakes.

Citizen scientist monitoring accurately reveals nutrient pollution dynamics in Lake Tanganyika coastal waters

Several studies in Lake Tanganyika have effectively employed traditional methods to explore changes in water quality in open waters; however, coastal monitoring has been restricted and sporadic, relying on costly sample and analytical methods that require skilled technical staff. This study aims in validating citizen science water quality collected data (nitrate, phosphate and turbidity) with those collected and measured by professional scientists in the laboratory. A second objective of the study is to use citizen scientist data to identify the patterns of seasonal and spatial variations in nutrient conditions and forecast potential changes based on expected changes in population and climate (to 2050). The results showed that the concentrations of nitrate and phosphate measured by citizen scientists nearly matched those established by professional scientists, with overall accuracy of 91% and 74%, respectively. For total suspended solids measured by professional and turbidity measured by citizen scientists, results show that, using 14 NTU as a cut-off, citizen scientist measurements of Secchi tube depth to identify lake TSS below 7.0 mg/L showed an accuracy of 88%. In both laboratory and citizen scientist-based studies, all measured water quality variables were significantly higher during the wet season compared to the dry season. Climate factors were discovered to have a major impact on the likelihood of exceeding water quality restrictions in the next decades (2050), which could deteriorate lake conditions. Upscaling citizen science to more communities on the lake and other African Great Lakes would raise environmental awareness, inform management and mitigation activities, and aid long-term decision-making.

The future of education and training in aquatic science within African Great Lakes

The African Great Lakes (AGL) harbor over 25% of the world’s unfrozen freshwater, and provide essential services to over 62 million people. Understanding the ecological functioning and social–economic values of these resources is critical to inform their mid- and long-term sustainable use. Management and protection of the lakes also depends on riparian communities’ involvement and knowledgeable experts that can address issues that arise, yet freshwater education and training in Sub-Saharan Africa suffer major challenges. This study reviewed and analyzed quantitative data from publications on AGL from between January 2010–2021, and investigated institutional websites and links to aquatic science programs in 10 countries. The study also evaluated qualitative data on expert judgement and student perception on challenges and hindrances to studying aquatic science in the region. The ascertained challenges included limited specialized academic programs, low uptake of academic programs, lack of timely informational access, the absence of career guidance, limited availability of skilled human resources, infrastructure, inadequate funding, and weak governance along with inadequate research. In the ten riparian countries of the AGL region, freshwater training was primarily offered as units in undergraduate programs, but rarely at postgraduate level. To bridge the gap between funding, highly motivated candidates, education, and training in freshwater science, we suggest pragmatic solutions such as the establishment of a global network of academic and training institutions, experts, and academic programs within the region and abroad to strengthen research, education, and training in aquatic science in the AGL region.

The Land–Water–Energy Nexus of Ruzizi River Dams (Lake Kivu Outflow, African Great Lakes Region): Status, Challenges, and Perspectives

Hydroelectric power (HP) represents the main source of electricity in Africa, including the Democratic Republic of Congo. The demand for new dam construction is high, and major projects are currently progressing through planning and implementation stages. New HP dams should comply with both past and emerging environmental requirements. River systems need water to maintain hydraulic and ecological functions. Flow regime disturbance can prevent rivers from providing their ecosystem services and disrupt riparian communities. Most dammed rivers in Africa are understudied, however, in terms of their environmental flow requirements. This study analysed the hydrological regime and water quality of the Ruzizi River. The research investigated conditions of minimum water flow and hydropeaking at the Ruzizi I HP dam in terms of land management constraints and ecological impacts. According to Gumbel’s hydrological model, a discharge of ∼130 m3/s showed the longest return period (12 years) among the most recurrent flows. By contrast, the maximum recorded discharge of 143 m3/s showed a return time of 76 years. Any discharge between 46 and 120 m3/s could occur at any time within three years. The discharge–hydropower production relationship for the power plant provided a possible minimum environmental flow of 28 m3/s (i.e., 25%). Drinking water quality was assessed according to WHO water quality index (WQI) standards. Turbidity (i.e., total suspended solids) upstream and downstream of dams correlated strongly with rainfall (r = 0.8; n = 12) and land use. WQI values observed in excess of WHO drinking water standards indicate that the Ruzizi River is currently unsuitable for drinking water purposes.

Limnospira fusiformis harbors dinitrogenase reductase (nifH)-like genes, but does not show N2 fixation activity

East African soda lakes (EASLs), some of them world-renowned for their large flocks of flamingos, range amongst the most productive aquatic ecosystems worldwide. The non-heterocytous filamentous cyanobacterium Limnospira fusiformis (formerly Arthrospira fusiformis or Spirulina platensis), forming almost unialgal blooms, is supposed to be a key driver in those ecosystems and is gaining increasing attention because of its nutritional value. Compared to phosphorus and carbon availability, these lakes show reduced nitrogen supply. We studied the possibility of molecular nitrogen (N2) fixation in Limnospira, as contradictory statements have been published, and some closely related taxa were confirmed as N2 fixers (diazotrophs). We cultivated nine isolates originating from various EASLs under nitrate-rich and nitrate-depleted conditions. We detected dinitrogenase reductase (nifH)-like genes in all strains; however, the genes grouped within nifH cluster IV that mostly contains nitrogenases not functioning in N2 fixation. Accordingly, incubations with 15N2 gas did not support N2 fixation activity of the investigated strains. Under laboratory conditions, all strains faded during nitrate-depleted growth after approximately three weeks. Both phycocyanin and chlorophyll-a dropped to a threshold, and chlorophyll fluorescence indicated a severe problem with nitrogen supply. In summary, our data indicate that the investigated Limnospira fusiformis strains are not capable of N2 fixation.

Geocultural variation in correlates of psychological distress among refugees resettled in the United States.

Attention to cultural variability in mental health symptoms could inform intervention targets; however, this is currently a neglected area of study. This study examined whether the associations between common mental health disorder (CMD) symptoms and predictors of CMDs varied cross-culturally. Participants were 290 refugees from three geocultural regions (Afghanistan, Great Lakes region of Africa, and Iraq and Syria) who recently resettled in the United States and completed assessments of CMD symptoms and predictors. Multilevel generalized linear modeling was used to examine the interactions between correlates of depressive, anxiety, and posttraumatic stress disorder (PTSD) symptoms and each of the three cultural reference groups. Relative to refugees from other regions, Iraqi and Syrian participants demonstrated stronger associations between the number of reported traumatic experiences and both depressive, B = 0.01, SE = .003, p = .003, and anxiety symptoms, B = 0.01, SE = .003, p < .001; Afghan participants showed a stronger association between physical quality of life and PTSD symptoms, B = 0.02, SE = .011, p = .037; and African participants demonstrated stronger associations between gender and symptoms of all three CMDs, Bs = 0.11-.020, SEs = .04-.06, ps = .005-.008, and weaker associations between traumatic event exposure and CMD symptoms, Bs = -0.01--0.02, SEs = .003-.006, ps = .000-.002. CMD symptoms likely present differently across cultures, with various predictors more salient depending on cultural backgrounds and differential experiences that vary based on context. These findings have implications for cross-cultural assessment research and mental health.

Sediment organic matter properties facilitate understanding nitrogen transformation potentials in East African lakes

East African lakes include the most productive and alkaline lake group in the world. Yet, they generally receive fewer nutrient inputs than the densely populated subtropical and temperate lakes in the northern hemisphere. In these lakes with insufficient supplies of inorganic nitrogen, the mineralization of benthic organic matter can play an important role in driving the nutrient cycle and nitrogen loss. Using a suite of stable 15N isotope dilution and tracer techniques, we examined five main processes of the sediment nitrogen cycle in 16 lakes and reservoirs of Tanzania and Kenya, East Africa: gross nitrogen mineralization, ammonium immobilization, dissimilatory nitrate reduction to ammonium (DNRA), and the dinitrogen (N2) production via denitrification and anaerobic ammonium oxidation (anammox). Gross nitrogen mineralization and ammonium immobilization showed the maximum values of 9.84 and 12.39 μmol N kg−1 h−1, respectively. Potential DNRA rates ranged from 0.22 to 8.15 μmol N kg−1 h−1 and accounted for 10 %–74 % (average 25 %) of the total dissimilatory nitrate reduction. Potential nitrate reduction rates in most lakes were dominated by denitrification with a contribution of 26 %–85 % and a mean of 65 %. We further found that the sediment nitrogen transformations were driven mainly by benthic organic matter properties and water column phosphate concentrations, reflecting microbial metabolic responses to the changing carbon and nutrients availability. For instance, autochthonous production of protein-like organic matter attributed to active sediment nitrogen mineralization, DNRA, and denitrification. In contrast, the high degree of humification caused by the inputs of terrestrial humic-like substances slowed down the sediment nitrogen transformations. The contribution of DNRA to total dissimilatory nitrate reduction was significantly positively correlated to sediment C: N ratios. These results indicate that predictions of sediment N supply and loss in East African lakes can be improved by incorporating sediment organic matter properties.

Outbreaks of Foot-and-Mouth Disease in Burundi, East Africa, in 2016, Caused by Different Serotypes.

Burundi is a small, densely populated country in the African Great Lakes region. In March 2016, several hundreds of cattle were reported with vesicular lesions, suggesting foot-and-mouth disease (FMD). Epithelial samples, saliva, and blood were collected in six of the affected provinces spread over the country. The overall seroprevalence of FMD virus (FMDV) in the affected herds, as determined by antibodies against FMDV non-structural proteins, was estimated at 87%. Antibodies against FMDV serotypes O (52%), A (44%), C (19%), SAT1 (36%), SAT2 (58%), and SAT3 (23%) were detected across the provinces. FMDV genome was detected in samples from five of the six provinces using rRT-PCR. FMDV was isolated from samples from three provinces: in Cibitoke province, serotypes A and SAT2 were isolated, while in Mwaro and Rutana provinces, only serotype SAT2 was isolated. In Bururi and Cankuzo provinces, the serological profile suggested a recent incursion with serotype SAT2, while in Bubanza province, the serological profile suggested past incursions with serotype O and possibly serotype SAT1. The phylogenetic assessments showed the presence of topotypes A/Africa/G-I and SAT2/IV, similarly to previously characterized virus strains from other countries in the region, suggesting a transboundary origin and necessitating a regional approach for vaccination and control of FMD.

Genetic architecture of adaptive radiation across two trophic levels.

Evolution of trophic diversity is a hallmark of adaptive radiation. Yet, transitions between carnivory and herbivory are rare in young adaptive radiations. Haplochromine cichlid fish of the African Great Lakes are exceptional in this regard. Lake Victoria was colonized by an insectivorous generalist and in less than 20 000 years, several clades of specialized herbivores evolved. Carnivorous versus herbivorous lifestyles in cichlids require many different adaptations in functional morphology, physiology and behaviour. Ecological transitions in either direction thus require many traits to change in a concerted fashion, which could be facilitated if genomic regions underlying these traits were physically linked or pleiotropic. However, linkage/pleiotropy could also constrain evolvability. To investigate components of the genetic architecture of a suite of traits that distinguish invertivores from algae scrapers, we performed quantitative trait locus (QTL) mapping using a second-generation hybrid cross. While we found indications of linkage/pleiotropy within trait complexes, QTLs for distinct traits were distributed across several unlinked genomic regions. Thus, a mixture of independently segregating variation and some pleiotropy may underpin the rapid trophic transitions. We argue that the emergence and maintenance of associations between the different genomic regions underpinning co-adapted traits that evolved and persist against some gene flow required reproductive isolation.

From a pair to a dozen: the piscivorous species of Haplochromis (Cichlidae) from the Lake Edward system

Piscivory is a common trophic niche among cichlids of the East African Great Lakes, including Lakes Edward and George. From these two lakes, we examined the taxonomic diversity of cichlid species with a piscivorous morphology. Prior to this study, two piscivorous species were formally described, Haplochromis squamipinnis and H. mentatus. We redescribe both species and describe an additional ten new species of Haplochromis with a piscivorous morphology: H. latifrons sp. nov., H. rex sp. nov., H. simba sp. nov., H. glaucus sp. nov., H. aquila sp. nov., H. kimondo sp. nov., H. falcatus sp. nov., H. curvidens sp. nov., H. pardus sp. nov., and H. quasimodo sp. nov. All twelve species differ in dominant male colour pattern (unknown for H. latifrons sp. nov. and H. curvidens sp. nov.) and morphological traits. The species can be divided into two morphological groups: the macrodontic piscivores and the microdontic piscivores. This division potentially reflects an ecological differentiation in habitat use, hunting technique, prey species, and prey size. We conclude that some 12–20% of the species from the cichlid assemblage of Lake Edward have a piscivorous morphology.

Altérité meurtrière et imaginaire antirwandophone au cœur de la discrimination xénophobe à travers le détournement des sigles et acronymes en RD Congo

Within the context of contemporary afro-pessimism, the African Great Lake Countries imaginary has been defined as a behavioral credo relation of mistrust, aggression and the logical extermination of the other. This study analyses the phenomenon of rwandophone alterity murderer resulting through the abuse of abbreviations and acronyms of DR Congo. The latter is about victimization lunacy as the basis of a xenophobe discrimination within the scapegoat process. This strategy operates as an expressive means of exorcization of individual and collective fantasy having the construction effect or the awakening of nationalist conscience.

Covid-19 Riskscapes: Viral Risk Perceptions in the African Great Lakes

ABSTRACT In this article we explore Covid-19 riskscapes across the African Great Lakes region. Drawing on fieldwork across Uganda and Malawi, our analysis centers around how two mobile, trans-border figures – truck drivers and migrant traders – came to be understood as shifting, yet central loci of perceived viral risk. We argue that political decision-making processes, with specific reference to the influence of Covid-19 testing regimes and reported disease metrics, aggravated antecedent geographies of blame targeted at mobile “others”. We find that using grounded riskscapes to examine localised renditions of risk reveals otherwise neglected forms of discriminatory discourse and practice.

Molecular phylogeny and speciation patterns in host-specific monogeneans (Cichlidogyrus, Dactylogyridae) parasitizing cichlid fishes (Cichliformes, Cichlidae) in Lake Tanganyika

Cichlidogyrus (including Scutogyrus) is the most speciose dactylogyridean monogenean genus known from African and Levantine cichlid fishes (Cichlidae). While its taxonomy is well established, little is known about the phylogenetic relationships and evolutionary history of this ectoparasite, especially from hosts belonging to one of the most impressive vertebrate radiations, the cichlid fishes from the East African Great Lakes and surrounding hydrological systems. Phylogenetic inference based on DNA sequences of the nuclear 18S, internal transcribed spacer 1 and 28S rDNA genes revealed that Cichlidogyrus parasitizing mainly West African cichlid tribes is paraphyletic with respect to species parasitizing hosts belonging to the East African cichlid radiation, which constitute a well-supported monophylum. Members of Cichlidogyrus from tylochromine and oreochromine hosts that colonised Lake Tanganyika only recently, cluster with their non-Lake Tanganyika relatives, indicating that they colonised Lake Tanganyika with their current host species, and did not jump over from any of the many cichlid species already present in the lake. The diversification of Cichlidogyrus in Lake Tanganyika seems to be driven by failure to diverge in old lineages of cichlids, cospeciation in more recently evolved ones, and host switching followed by parasite duplication at the level of the various host tribes. Evaluation of host specificity and structural evolution of haptoral and reproductive organs in Lake Tanganyika Cichlidogyrus revealed that strict specialist species together with larval hook size represent the ancestral state of haptor configuration, suggesting that members of Cichlidogyrus in this system evolved from a very simple form to a more complex one similarly to their West African congeners. Generalist species among Cichlidogyrus with a sclerotized vagina parasitizing ancient Lake Tanganyika lineages seem to have developed a different hook configuration, most probably to ensure successful colonisation of new, phylogenetically unrelated hosts.

Rapid Parallel Morphological and Mechanical Diversification of South American Pike Cichlids (Crenicichla).

Explosive bouts of diversification are one of the most conspicuous features of the tree of life. When such bursts are repeated in similar environments, it suggests some degree of predictability in the evolutionary process. We assess parallel adaptive radiation of South American pike cichlids (Crenicichla) using phylogenomics and phylogenetic comparative methods. We find that species flocks in the Uruguay and Iguazú River basins rapidly diversified into the same set of ecomorphs that reflect feeding ecology. Both adaptive radiations involve expansion of functional morphology, resulting in unique jaw phenotypes. Yet, form and function were decoupled such that most ecomorphs share similar mechanical properties of the jaws (i.e., jaw motion during a feeding strike). Prey mobility explained 6- to 9-fold differences in the rate of morphological evolution but had no effect on the rate of mechanical evolution. We find no evidence of gene flow between species flocks or with surrounding coastal lineages that may explain their rapid diversification. When compared with cichlids of the East African Great Lakes and other prominent adaptive radiations, pike cichlids share many themes, including the rapid expansion of phenotypic diversity, specialization along the benthic-to-pelagic habitat and soft-to-hard prey axes, and the evolution of conspicuous functional innovations. Yet, decoupled evolution of form and function and the absence of hybridization as a catalyzing force are departures from patterns observed in other adaptive radiations. Many-to-one mapping of morphology to mechanical properties is a mechanism by which pike cichlids attain a diversity of feeding ecologies while avoiding exacerbating underlying mechanical trade-offs. [Adaptive radiation; ecological opportunity; feeding kinematics; functional trade-off; hybridization; introgression.].

Need for harmonized long-term multi-lake monitoring of African Great Lakes

To ensure the long-term sustainable use of African Great Lakes (AGL), and to better understand the functioning of these ecosystems, authorities, managers and scientists need regularly collected scientific data and information of key environmental indicators over multi-years to make informed decisions. Monitoring is regularly conducted at some sites across AGL; while at others sites, it is rare or conducted irregularly in response to sporadic funding or short-term projects/studies. Managers and scientists working on the AGL thus often lack critical long-term data to evaluate and gauge ongoing changes. Hence, we propose a multi-lake approach to harmonize data collection modalities for better understanding of regional and global environmental impacts on AGL. Climate variability has had strong impacts on all AGL in the recent past. Although these lakes have specific characteristics, their limnological cycles show many similarities. Because different anthropogenic pressures take place at the different AGL, harmonized multi-lake monitoring will provide comparable data to address the main drivers of concern (climate versus regional anthropogenic impact). To realize harmonized long-term multi-lake monitoring, the approach will need: (1) support of a wide community of researchers and managers; (2) political goodwill towards a common goal for such monitoring; and (3) sufficient capacity (e.g., institutional, financial, human and logistic resources) for its implementation. This paper presents an assessment of the state of monitoring the AGL and possible approaches to realize a long-term, multi-lake harmonized monitoring strategy. Key parameters are proposed. The support of national and regional authorities is necessary as each AGL crosses international boundaries.

Calcemia, Vitamin D and seasonal influences in preeclampsia in Goma

Background: The etiology of preeclampsia remains less well known. It is noted that low vitamin D levels are associated with a high risk of preeclampsia (PE). Calcium (Ca2+) levels during pregnancy appear to be involved in pregnancy-induced hypertension. Recent studies indicate that serum calcium levels may have a role in preeclampsia. Vitamin D promotes absorption of proper concentration of calcium in the blood which helps to lower blood pressure. The complications associated with calcium deficiency during a normal pregnancy are numerous and have not been extensively studied in Goma. Objective: To assess blood calcium levels (ionic and total) in preeclamptic women and to analyse the seasonal influence on preeclampsia in Goma. Method: A prospective case-control study (without matching) of 190 pregnant women without cardiovascular or endocrine diseases for a case-control ratio of 1∶1 was conducted in six hospitals in Goma. Blood ionogram was performed by an automated system directly after blood sampling and vitamin D was measured using enzyme-linked immunosorbent method. Results: The mean ionised calcium level in preeclamptic woman was 1.24±0.16 mmol/L (0.48-1.59) compared to 1.27±0.17 mmol/L (0.88-2.30) in normal pregnant woman (p=0.214). A slight negative correlation between blood calcium and blood pressure was observed in pregnant women. Low vitamin D levels were associated with preeclampsia. Hypovitaminosis D in the preeclamptic group was more observed during the rainy season than during the dry season. Pregnancies complicated by PE were from fertilisations occurring during the rainy season while the dry season was characterised by a high admission of preeclamptics. Conclusion: The study found that preeclamptic women in Goma had hypocalcemia. There was also a weak negative correlation between blood pressure and serum calcium levels. The majority of preeclamptics were diagnosed during the dry season, while conception with a PE complication occurred during the rainy season. As this is a first study in this area for the Great Lakes region of Africa, a more in-depth study with a larger sample size is desired.

Status and changes of water quality in typical near-city zones of three East African Great Lakes in Tanzania.

Tanzania is the only country bordering all three transboundary East African Great Lakes, i.e., Lake Victoria, Lake Tanganyika, and Lake Nyasa (Lake Malawi). This study investigated the spatiotemporal variability of basic physicochemical parameters of nearshore surface waters in Mwanza Gulf (Lake Victoria), Kigoma Bay (Lake Tanganyika), and Wissmann Bay (Lake Nyasa). Water quality was evaluated using the water quality index (WQI) method. Results showed that N and P nutrient pollution was relatively severe in central and southern parts of Mwanza Gulf owing to external agricultural emissions and internal release associated with physically disturbed sediment resuspension. External inputs from inflowing surface runoffs from the city of Mwanza typically enhanced N loading in northern parts of the gulf during the rainy season. Poor water quality was found in central and southern parts of Mwanza Gulf, especially in the rainy season. Algal blooms and NH4+-N (total P and total N) were the main factors driving water quality degradation in the rainy (dry) season. Kigoma Bay and Wissmann Bay both had good water quality, except in river mouth areas in Lake Nyasa during the rainy season. The degradation in water quality was caused primarily by increased land-based nutrient and turbidity inputs. To respond to challenges associated with climate change and local socioeconomic development, long-term monitoring of the lacustrine environment and systematic limnological studies will be required, not only in the three bays but also more widely throughout the three lakes and their basins.

THE AFRICAN GREAT LAKES REGION: Obstacle and asset to the implementation of the African Continental Free Trade Area Agreement in the Democratic Republic of the Congo (DRC)

This paper aims to demonstrate why the geopolitics of the African Great Lakes region canbe both an obstacle and an asset to the effective implementation of the AfCFTA in the DRC. It begins by noting the negative factors unfavourable to the successful