Kenya's Lake Research Articles

Effect of Supplier Appraisal on Performance of Construction Projects of Counties in Lake Region Economic Bloc, Kenya

Procurement Laws and Regulations 2015 are a yard stick that directs how buying of goods, services, and works by governments and state-owned businesses should be conducted (Thiankolu, 2019). However, there exists an absence of compliance to these laws as envisaged by its framers which results to bias and uncompetitive bidding, evaluation and award of contracts process something that compromises the effectiveness of the project's accomplishment (Kagume & Wamalwa, 2018). The primary objective relating to this research entailed investigating the effect of supplier appraisal on performance of construction projects of counties in Lake Region Economic Bloc, Kenya. The study adopted a descriptive research design with stratified random sampling technique being applied to select a sample of 342 respondents from a total population of 2346 county officials that include finance and procurement officers. A survey instrument was utilized for gathering data, using questions that were both open and closed-ended. The survey instrument was piloted in Marsabit County. It was conducted to ensure that the instrument is both valid and reliable. SPSS was used to perform analysis of data. Supplier appraisal was established to have a positive and significant correlation on the performance of counties in Lake Region Economic Bloc with a co-efficient of correlation R value of 0.816 and P<0.05. Supplier appraisal with a coefficient of determination (R2=0.700, P<0.05) could account for 70% of variation in the performance of construction projects if other factors were to be held constant. Specifically, when Supplier appraisal increases by a single unit, there will be a subsequent increase in performance of construction projects by 0.885 units (β1=0.885, P<0.05). This suggests a positive and strong correlation between supplier appraisal and performance of construction projects and thus the study suggests that evaluating suppliers using technical, financial, and legal criteria might help construction projects succeed in Kenya's Lake Region Economic Bloc.

Biogeography of freshwater plants in four major lakes in Kenya

Freshwater plants play a pivotal role in the health and functioning of freshwater ecosystems, and they also offer a variety of benefits to humans. Despite their importance, there is a significant gap in our understanding of the macroecology of freshwater plants in tropical regions, where biodiversity is typically high, and ecosystems face substantial pressures from human activities. To bridge this knowledge gap, we conducted extensive field surveys and applied statistical methods to understand the patterns of distribution, density, and diversity of freshwater plants and their relationship with abiotic components in four freshwater lakes in Kenya. We aimed to answer four key questions: (1) How many freshwater plant species occur in these lakes? (2) What proportion of these freshwater plant species are native and alien to Kenya? (3) What proportion of these species have a history of being invasive somewhere in the world, including in Kenya? (4) Which water and sediment characteristics are significantly associated with the presence, density, and diversity of freshwater plants in the lakes? We inventoried a total of 163 freshwater plant species, of which 114 were native to Kenya and 49 were alien. Online database searches revealed that 114 species had a history of invasion globally, with 22 species already invasive in Kenya. Our statistical analysis showed that the presence and density of plant species were positively correlated with pH and turbidity, but negatively correlated with soluble reactive phosphorus in both water and sediments, ammonia-nitrogen in sediments, and nitrate-nitrogen in water. Shannon-Wiener diversity of the plant species was positively correlated with ammonia-nitrogen in water and nitrate-nitrogen in sediments but negatively correlated with longitude and electrical conductivity of the water. Pielou’s evenness within the communities showed positive correlations with soluble reactive phosphorus in both water and sediments, ammonia-nitrogen in sediments, and nitrate-nitrogen in water but was negatively correlated with water turbidity and pH. The number of species with a history of invasion was positively correlated with longitude and electrical conductivity but negatively correlated with ammonia-nitrogen and nitrate-nitrogen in water. This extensive inventory not only enriches our understanding of the biodiversity within these freshwater plant communities but also highlights the potential risks posed by species with a history of being invasive. The findings regarding environmental variables linked to the presence, density, diversity, and invasive potential of these species underscore the complexity of freshwater ecosystems and the array of factors influencing the composition of freshwater plant communities.

Assessment of Relationship Between Human Resource Planning Strategies and Job Satisfaction in the Lake Region Economic Bloc County Governments in Kenya

Human resource planning encompasses predicting quantity, quality and category of human resources requirements in organizations to ensure that they are suitably redeployed and utilized optimally by organizations. Accurate predictions ease the rationalization of staff to improve its performance and create a conducive working environment. In that regard, organizations in the public and private sectors are formulating and deploying several strategies to enhance employee job satisfaction and gain a competitive edge. Despite the emphasis on job satisfaction, a review of available literature indicated limited focus on the relationship between human resource planning strategies and job satisfaction. This paper assessed the relationship between human resource planning strategies and job satisfaction in Kenya's Lake Region Economic Bloc County Governments. The study used the equity theory and the target population was all employees engaged by the 14 counties in Kenya's Lake Region Economic Bloc County Governments. Three counties: Kisumu, Bomet and Kakamega, which had employed 14,361 workers were sampled. The study sample consisted of 374 respondents, who arrived at the study using the Morgan and Krejcie sampling formula. A questionnaire was used to collect data analysed using SPSS for descriptive and inferential statistics and presented using tables. Regression analysis indicated that human resource planning strategies are positively and significantly related to job satisfaction (B = 0.939, p = .000). Thus, the study concluded that a significant relationship exists between human resource planning strategies and job satisfaction in Kenya's Lake Region Economic Bloc County Governments. The study recommends that county governments in the Lake Region Economic Bloc in Kenya emphasize implementing forecasting and restructuring strategies objectively and rationally to enhance employees' job satisfaction

STAKEHOLDER-INVOLVEMENT IN WATER RESOURCE RELATED CONFLICT MANAGEMENT IN LAKE TURKANA BASIN OF KENYA

Lake Turkana is the largest permanent desert lake in the world and a crucial water source in Turkana County, sustaining thousands of livelihoods. The ethnic groups are primarily nomadic pastoralists. The region is heavily prone to perennial water resources related conflict resulting into perennial displacement of human beings and animals. Prior studies established that perennial resource conflict is fuelled by stakeholders. The study aimed to determine stakeholders' participation in managing water resource conflict in Kenya's Lake Turkana Basin. A descriptive research design anchored on negotiation theory was applied. A sample of 36 respondents were contacted through a structured questionnaire, Key Informant Interview (KII) schedule, observation guide and Focused Group Discussions (FGDs). The study revealed limited stakeholder exposure to conflict management and biased participation. The study concluded that stakeholder involvement and poor stakeholder identification bred water resource related conflict. In matters conflict management, the under-developed road structures and poor communication facilities make it difficult to mobilize people in the vast lake basin The study recommends broader stakeholder inclusion in future conflict management, applying Alternative Dispute Resolution (ADR) methods such as enhanced traditional dispute resolution mechanism, mediation and negotiation.

The Isolation, Screening, and Characterization of Polyhydroxyalkanoate-Producing Bacteria from Hypersaline Lakes in Kenya

Extremophilic microorganisms such as those that thrive in high-salt and high-alkaline environments are promising candidates for the recovery of useful biomaterials including polyhydroxyalkanoates (PHAs). PHAs are ideal alternatives to synthetic plastics because they are biodegradable, biocompatible, and environmentally friendly. This work was aimed at conducting a bioprospection of bacteria isolated from hypersaline-alkaliphilic lakes in Kenya for the potential production of PHAs. In the present study, 218 isolates were screened by Sudan Black B and Nile Red A staining. Of these isolates, 31 were positive for PHA production and were characterized using morphological, biochemical, and molecular methods. Through 16S rRNA sequencing, we found that the isolates belonged to the genera Arthrobacter spp., Bacillus spp., Exiguobacterium spp., Halomonas spp., Paracoccus spp., and Rhodobaca spp. Preliminary experiments revealed that Bacillus sp. JSM-1684023 isolated from Lake Magadi had the highest PHA accumulation ability, with an initial biomass-to-PHA conversion rate of 19.14% on a 2% glucose substrate. Under optimized fermentation conditions, MO22 had a maximum PHA concentration of 0.516 g/L from 1.99 g/L of cell dry weight and 25.9% PHA conversion, equivalent to a PHA yield of 0.02 g/g of biomass. The optimal PHA production media had an initial pH of 9.0, temperature of 35 °C, salinity of 3%, and an incubation period of 48 h with 2.5% sucrose and 0.1% peptone as carbon and nitrogen sources, respectively. This study suggests that bacteria isolated from hypersaline and alkaliphilic tropical lakes are promising candidates for the production of polyhydroxyalkanoates.

Assessment of Rising Water Levels of Rift Valley Lakes in Kenya: The Role of Meteorological Factors

The impacts of increased water levels in Kenyan lakes are a major problem that is affecting communities and their livelihoods. Upsurge in water levels of the Rift Valley Lakes is one of the recent climate extremes witnessed over Eastern Africa where the rises appear to be consistent with the occurrence of enhanced seasonal rains between 2016 and 2020. Considering that many explanations have been provided as possible causes, there is still little empirical evidences. This study aimed at assessing the link between meteorological factors and the rises in lake levels in order to see if these can explain the causes. Further using surface observations potential to predict the water levels was examined. Datasets on rainfall, temperature and water levels from four Lakes in Kenya were used to establish the changes in these variables using statistical methods. Generalized Linear Models were used to predict the water levels in the study lakes. Results indicate that rainfall and temperature as well as other climate drivers has been changing over the last recent years with increased precipitation being consistent with the observed high stands in the Rift Valley lakes. Specifically, the results of the forecasted levels indicate substantial and slight increase for lake levels in Naivasha while the Lake Baringo levels are predicted to rise sharply within the study data periods.

Physicochemical Properties and Heavy Metal Concentration in Borehole Water of Boko Haram Affected Areas of Madagali and Michika, Adamawa State, Nigeria

The impacts of increased water levels in Kenyan lakes are a major problem that is affecting communities and their livelihoods. Upsurge in water levels of the Rift Valley Lakes is one of the recent climate extremes witnessed over Eastern Africa where the rises appear to be consistent with the occurrence of enhanced seasonal rains between 2016 and 2020. Considering that many explanations have been provided as possible causes, there is still little empirical evidences. This study aimed at assessing the link between meteorological factors and the rises in lake levels in order to see if these can explain the causes. Further using surface observations potential to predict the water levels was examined. Datasets on rainfall, temperature and water levels from four Lakes in Kenya were used to establish the changes in these variables using statistical methods. Generalized Linear Models were used to predict the water levels in the study lakes. Results indicate that rainfall and temperature as well as other climate drivers has been changing over the last recent years with increased precipitation being consistent with the observed high stands in the Rift Valley lakes. Specifically, the results of the forecasted levels indicate substantial and slight increase for lake levels in Naivasha while the Lake Baringo levels are predicted to rise sharply within the study data periods.

Water quality assessment, multivariate analysis and human health risks of heavy metals in eight major lakes in Kenya

This study evaluates water quality, concentrations and health risks of heavy metals (HMs) in eight major lakes in Kenya namely Naivasha, Elementaita, Nakuru, Baringo, Bogoria, Turkana, Victoria and Magadi. Water quality was assessed using water quality index (WQI) and pollution evaluation index (PEI), while human health risk associated with ingestion and dermal contact of HMs was assessed using hazard quotients (HQ) and hazard index (HI). Principal component analysis (PCA) and hierarchical cluster analysis (HCA) were used to deduce the probable sources of the HMs. The average concentration of aluminium (Al), molybdenum (Mo), manganese (Mn), nickel (Ni), arsenic (As), zinc (Zn), selenium (Se), lead (Pb), chromium (Cr), mercury (Hg), cobalt (Co) and cadmium (Cd) in the eight lakes was 824.6, 66.1, 58.9, 16.2, 8.40, 7.84, 6.91, 4.65, 2.66, 0.86, 0.78 and 0.46, respectively, all in μg/L. Al, Mn, As, and Mo were relatively high in Rift Valley lakes and exceeded the maximum permissible levels for drinking water. Notably, high HM concentrations were recorded at the entry points of rivers and areas with high human activities. Lake Magadi had the highest average WQI of 158.8 followed by lake Elementaita (128.4), Bogoria (79.5), Nakuru (73.3), Turkana (57.6), Victoria (52.3), Baringo (42.6) and Naivasha (25.5). Lake Magadi also had the highest average PEI of 40.0 followed by Elementaita (30.1), Bogoria (16.2), Nakuru (15.7), Victoria (10.8), Baringo (9.57), Turkana (9.53) and Naivasha (5.12). Based on WQI, Lake Naivasha water was excellent for drinking, Lake Victoria, Turkana, Baringo, Nakuru, and Bogoria had good water, but water from Lake Elementaita and Magadi was of poor quality. PEI classified the lakes as minimally polluted except Lake Magadi. Multivariate analysis concluded that Pb, Cr, Ni and Se had anthropogenic sources, mainly agricultural and urban runoff, but other HMs had natural influence. Although the HMs did not pose any health risks through dermal contact, HQingestion was >1 for adults and children consuming water from Lake Elementaita, Nakuru, Bogoria and Magadi due to non-carcinogenic risks associated with As, Zn and Mo. These results are important for formulating the necessary remediation policies to improve water quality in the eight lakes.

Predation on planktonic ciliates in Kenyan soda lakes

Ciliated protozoa are important components of the plankton of aquatic systems with ability to recycle nutrients and to link microbial food webs to metazoans. This is because they are numerous and have higher growth rates compared to other unicellular eukaryotes of similar size. Predation and competition are some of the factors that negatively affect their abundance and growth. Studies documenting the impact of predation by zooplankton on ciliates have been conducted in marine and freshwaters waters but are lacking in tropical waters especially soda lakes in Kenya. In this study, growth rates of planktonic ciliates were estimated in four soda lakes, Lakes Bogoria, Elmenteita, Simbi and Sonachi, using predator exclusion experiments. In the experiments, ciliate populations increased faster in incubations of lake water with the >40 µm fraction removed than in untreated controls. The difference in these rates was taken as an estimate of predation by zooplankton >40 µm (Mz), and ranged from 0.091 to 3.171 d−1. Our best estimates of growth rates for particular ciliates abundant enough to derive estimates for ranged from 0.18 to 4.78 d−1. When removing the >40 µm fraction did not result in increased numbers of ciliates relative to controls, we hypothesized that this was due to predators within the <40 µm fraction (Mc) and their release from zooplankton predators. We assessed and supported this hypothesis by looking at the production of ciliates in different feeding guilds. The significance of predation on ciliates to the food webs of soda lakes is discussed.

Linkages between land cover change, lake shrinkage, and sublacustrine influence determined from remote sensing of select Rift Valley Lakes in Kenya

The Great Rift Valley system is home to many volcanic and tectonic lakes including some of the world's oldest and deepest lakes. These lakes host a rich heritage of biodiversity that is endangered by recent drastic hydrologic changes due to multiple natural and anthropogenic stressors in the catchment areas of some of the lakes. This study utilized Landsat TM, ETM+, and OLI data to conduct a systematic investigation of the relationship between hydrological dynamics in the basins of four Rift Valley lakes (Nakuru, Baringo, Bogoria, and Elementaita) and recent land cover and land-use change. The Modified Normalized Difference Water Index (MNDWI) proved to be more accurate and robust for delineating water surface areas when compared to the output of Normalized Difference Vegetation Index (NDVI) and classification algorithms. NDVI was successful when delineating water surface at Lake Baringo but not in Lakes Bogoria, Nakuru, and Elementaita, whose surfaces were dominated by algae. All the lakes expanded substantially after 2010 submerging surrounding areas leading to disruption of livelihoods, property damage, and displacement of thousands of people. The recent drastic hydrologic changes have multiple causations including land cover and land use change, increase in rainfall, and possible change in geogenic water input due to tectonic activity. The rapid rise in water levels appears to have altered the biogeochemical balance of the hypersaline lakes with severe ramifications on the rich biodiversity that is supported by the lakes.

Gendered perceptions of power and decision‐making in rural Kenya

AbstractDevelopment policies and programmes rest on assumptions about what constitutes power and how to change power dynamics. However, they rarely consider local understandings of power. In this article we ask how these common assumptions correspond with socially and culturally specific ideas about what power is, who can hold power, and how power can be transferred, in rural communities in Kenya's lake region. We find that men and women are constantly negotiating for power in the household, within the bounds of their gendered limitations. And the predominant zero‐sum conception of power may undermine common development approaches to empowerment. However, the results also highlight some exceptions to this conceptualization, as well as the value of taking a whole‐family approach to empowerment.

New archaeological investigations at the Lothagam harpoon site at Lake Turkana

The Lothagam harpoon site in north-west Kenya's Lake Turkana Basin provides a stratified Holocene sequence capturing changes in African fisher-hunter-gatherer strategies through a series of subtle and dramatic climate shifts (Figure 1). The site rose to archaeological prominence following Robbins's 1965–1966 excavations, which yielded sizeable lithic and ceramic assemblages and one of the largest collections of Early Holocene human remains from Eastern Africa (Robbins 1974; Angel et al. 1980).

Impacts of Mau Forest Catchment on the Great Rift Valley Lakes in Kenya

Remote sensing and GIS applications are being widely used for various projects relating to natural resource management. Forests are very important national assets for economic, environmental protection, social and cultural values and should be conserved in order to realize all these benefits. Kenya’s forests are rapidly declining due to pressure from increased population, technological innovation, urbanization human development and other land uses. Mau forest is one of the major forests in Kenya that is a catchment area for many Great Rift Valley lakes within the country and faces a lot of destruction. Continued destruction of the Mau forest will cause catastrophic environmental damage, resulting in massive food crises and compromising the livelihoods of millions of Kenyans, and the possible collapse of the tourism industry. The purpose of this research was to investigate the relationship between the increasing rate of deforestation and the reduction of the volumes of water in the neighboring lakes between the years 1989 to 2010. Satellite images from Landsat-5 Thematic Mapper (TM) and Landsat-7 Enhanced Thematic Mapper (ETM+) were used for the detection of changes in the Mau forest and the dynamics of the neighboring water bodies that included lakes: Naivasha, Baringo, Nakuru, Elementaita and Bogoria. The research showed that from a period of 1989 to 2010 Mau forest has been decreasing due to deforestation and the water bodies have irregular dynamics in that, from 1989 to 2000, there was rise in the volume of water, this is attributed to the El Nino rains experienced in the country during the year 1997 and 1998. But between 2000 and 2010 the volume decreased as the forest is also decreasing. It is recommended that the government creates awareness to sensitize the public on the importance of such forests as catchment areas in Kenya.

Making protection of biodiversity count

Conservation![Figure][1] Kenya's Lake Nakuru National Park PHOTO: BJORN CHRISTIAN TORRISSEN/WIKIMEDIA COMMONS Global protected areas aim to protect biodiversity, but they do not currently protect threatened species very well. Venter et al. report that 85% of threatened vertebrates need

Once and Future Climate Change

[Changing Climates Special Issue Index][1] ![Figure][2] Wet to dry. Kenya's Lake Magadi, now alkaline and mostly dry, once teemed with freshwater fish; a core drilled here will reveal ancient climate swings. CREDIT: © STEVE BLOOM IMAGES/ALAMY Anthropogenic climate change is now a part of our reality. Even the most optimistic estimates of the effects of contemporary fossil fuel use suggest that mean global temperature will rise by a minimum of 2°C before the end of this century and that CO2 emissions will affect climate for tens of thousands of years. A key goal of current research is to predict how these changes will affect global ecosystems and the human population that depends on them. This special section of Science focuses on the current state of knowledge about the effects of climate change on natural systems, with particular emphasis on how knowledge of the past is helping us to understand potential biological impacts and improve predictive power. Four News stories focus on past and future impacts of climate change and the techniques that researchers are using to study them. Gibbons examines the role of climate variability in hominin evolution in Africa, and Pennisi profiles an effort to use sediment cores to document that variability. Kintisch explores whether coastal wetlands will be able to outclimb rising seas. And Pennisi offers a snapshot on the use of historical photographs to study climate impacts. Four Reviews discuss recent research on the current and future effects of climate change as informed by our understanding of changing climates in the paleorecord. Diffenbaugh and Field review the physical conditions that are likely to shape the impacts of climate change on terrestrial ecosystems, showing that they will face rates of change unprecedented in the past 65 million years. Norris and colleagues review the Cenozoic history of oceanic change; despite some short-lived past analogs, the oceans will also experience more rapid change than ever before. Turning to ecology, Blois and colleagues discuss how climate changes can affect biotic interactions and how these insights might inform our understanding of future interactions. Moritz and Agudo discuss the prospects for species survival, weighing the evidence for persistence versus catastrophic decline. Three Reviews focus on more specific impacts of climate change. Its influence on infectious disease is considered by Altizer and colleagues, who use examples from a wide range of host-pathogen systems to assess whether we are close to a predictive understanding of climate-disease interactions and their potential future shifts. Wheeler and von Braun assess the prospects for human food security, with particular attention to potential impacts on food supply in the world's more impoverished countries . Finally, Post and colleagues take a regional focus, reviewing the ecological consequences of current sea ice decline in the polar regions, the part of the world where the reality of changing climate is perhaps at its most stark. [1]: http://www.sciencemag.org/site/special/climate2013/index.xhtml [2]: pending:yes

Ecology and community structure of ciliated protists in two alkaline–saline Rift Valley lakes in Kenya with special emphasis on Frontonia

GEOFFREY ODHIAMBO ONG’ONDO1,2*, ANDREW WAMALWAYASINDI1, STEVE OMONDI ODUOR1, STEFFEN JOST2, MICHAEL SCHAGERL3, BETTINA SONNTAG4 AND JENS BOENIGK2 1 EGERTON UNIVERSITY, PO BOX 536, 20115 EGERTON, KENYA, DEPARTMENT OF GENERAL BOTANY, UNIVERSITY DUISBURG ESSEN, UNIVERSITATSSTR. 5, D-45141 ESSEN, GERMANY, DEPARTMENT OF LIMNOLOGY, UNIVERSITY OF VIENNA, ALTHANSTRAsE 14, A-1090 VIENNA, AUSTRIA AND RESEARCH INSTITUTE FOR LIMNOLOGY, MONDSEE, MONDSEESTRASSE 9, A-5310 MONDSEE, AUSTRIA

Using ICT for fish marketing: the EFMIS model in Kenya

Small-scale fisheries in developing countries often perform sub-optimally owing to lack of vital market information, leading to inefficiencies, inequity, and post-harvest losses. The mobile phone, which is the fastest growing communications media in Africa, may be most suited for addressing market information gaps. The Enhanced Fish Market Information Service (EFMIS), an ICT pilot project based on mobile phones, has been implemented in Kenya's Lake Victoria fisheries for 3 years. The objective of the project is to enhance fish trade and incomes for the fisher community through improved access to market information. Through the system, data from fish landing sites and inland urban markets is continuously relayed to a central database where it is appropriately packaged into a format that users can access in real time by sending a query through mobile phone SMS. The system is automated and responds within 10 seconds. Market information is also disseminated through monthly electronic bulletins. The EFMIS mode...

Hidden diversity in diatoms of Kenyan Lake Naivasha: a genetic approach detects temporal variation

This study provides insights into the morphological and genetic diversity in diatoms occurring in core sediments from tropical lakes in Kenya. We developed a genetic survey technique specific for diatoms utilizing a short region (76-67 bp) of the ribulose-1,5-bisphosphate carboxylase/oxygenase large subunit (rbcL) gene as genetic barcode. Our analyses (i) validated the use of rbcL as a barcoding marker for diatoms, applied to sediment samples, (ii) showed a significant correlation between the results obtained by morphological and molecular data and (iii) indicated temporal variation in diatom assemblages on the inter- and intra-specific level. Diatom assemblages from a short core from Lake Naivasha show a drastic shift over the last 200 years, as littoral species (e.g. Navicula) are replaced by more planktonic ones (e.g. Aulacoseira). Within that same period, we detected periodic changes in the respective frequencies of distinct haplotype groups of Navicula, which coincide with wet and dry periods of Lake Naivasha between 1820 and 1938 AD. Our genetic analyses on historical lake sediments revealed inter- and intra-specific variation in diatoms, which is partially hidden behind single morphotypes. The occurrence of particular genetic lineages is probably correlated with environmental factors.

Lake Naivasha, Kenya: Ecology, Society and Future

Abstract We examine the degradation of the natural capital and ecosystem services of an important tropical lake, Kenya's Lake Naivasha, in the context of human activities and exploitation since the mid-20th century. These factors have culminated in the recent emergence of innovative governance arrangements with potential contributions to the future sustainability of the lake ecosystem. Lake Naivasha maintains high ecological interest and biodiversity value despite its food web being controlled, at three trophic levels, by alien species for the past 40 years. The lake now has very high economic value, being the centre of Kenya's floricultural industry, itself the top foreign exchange earner for the country. It became internationally-renowned in 1999 as one of the first wetland sites worldwide to be nominated by the government for Ramsar status as a result of local action, guided by the Lake Naivasha Riparian Association (LNRA). This led, in 2004, to gazettement by the Kenyan Government for the management o...

FLUCTUATING ALGAL FOOD POPULATIONS AND THE OCCURRENCE OF LESSER FLAMINGOS (PHOENICONAIAS MINOR) IN THREE KENYAN RIFT VALLEY LAKES1

The last two decades have witnessed increasing episodes of lesser flamingo die‐offs in East Africa. Based on data on phytoplankton composition, biomass, and flamingo population density in three alkaline‐saline lakes of Kenya (Bogoria, Nakuru, and Oloidien) in 2001–2010, this study explored the link between sudden flamingo deaths and fluctuations in algal food quantity and quality. The phytoplankton biomass ranged from 13 to 768 mg · L−1. Similarly, flamingo numbers varied widely from <1,000 to >500,000 individuals in the study lakes. The dominance of the cyanobacterium Arthrospira fusiformis (Woron.) Komárek et J. W. G. Lund was interrupted at irregular intervals in each lake and replaced partly by populations of different species of the nostocalean Anabaenopsis or by the picoplanktonic chlorophyte Picocystis salinarum Lewin. The populations of Anabaenopsis have the potential of blocking the flamingo food filtration system with their large and slimy colonies; moreover, they are able to produce cyanotoxins. Estimates of flamingo populations suggest that low flamingo numbers coincided with periods of low algal food quantity and/or poor quality. A food deficit can be theorized to have two effects on the flamingos: (i) it weakens them to the point of being susceptible to attacks of infective diseases, such as the ones caused by Mycobacterium avium and Pseudomonas aeruginosa, and (ii) it predisposes them to poisoning by cyanotoxins and pollutants, by reducing their capacity to handle toxic substances. This study therefore concludes that the challenges facing the flamingos are associated with changes in their environment, which affect food and water supply.