The study was conducted in Lake Baringo, Kenya, and determined quantitative relationships between... more The study was conducted in Lake Baringo, Kenya, and determined quantitative relationships between water‐level changes, water quality, and fishery production for purposes of evidence‐based lake basin management. Long‐term data on water level (1956–2020), water quality (2008–2021), and fisheries yields (1982–2021) from Lake Baringo were analysed using a combination of statistical methods. Linear and waveform regression analyses were used to describe patterns of lake‐level fluctuations over time, while Pearson's correlation was applied to determine the concordance of lake level changes with water quality parameters, landings, and condition of fish species. Principal components analysis (PCA) results grouped the study period into different years based on annual water quality variable levels. Locally weighted scatter plot smoothing (LOWESS) analysis showed the annual lake level amplitude declined over time with peak values in 1964 (8.6 m) and 2008 (9.4 m). The waveform regression sig...
Lakes & Reservoirs: Science, Policy and Management for Sustainable Use, 2021
Lacustrine and riverine ecosystems provide important goods and services, including being habitats... more Lacustrine and riverine ecosystems provide important goods and services, including being habitats for aquatic biodiversity, local micro‐climate moderation and a source of economic livelihoods for riparian communities. At the same time, however, they fact continuing anthropogenic and natural threats that can affect their water quality, ecological integrity and biodiversity. The present study focused on assessing spatio‐temporal variations in water quality and trophic status of Lake Baringo, a Ramsar site in Kenya. A number of physicochemical parameters, including nutrient loads, trophic status and organic pollution indices, were evaluated for the lake from water samples collected from March 2008 to December 2020. The results of the present study indicated five parameters (turbidity, fluoride, , total phosphorus and DO) exceeded the permissible limits for drinking water based on WHO standards. The water quality index (WQI) values ranged between 556.04 and 693.54, being well above the ...
Conservation and Rehabilitation of Lake Kanyaboli Wetland, Kenya Phillip Okoth Raburu Department ... more Conservation and Rehabilitation of Lake Kanyaboli Wetland, Kenya Phillip Okoth Raburu Department of Fisheries, Moi University, PO Box 3900 ... Fellow researchers to whom l am greatly indebted include the late Peter Ochumba, Omondi Akech, Otieno Manyalla, and technicians ...
One of the most important issues in the world, both for present and future genera-tions, concerns... more One of the most important issues in the world, both for present and future genera-tions, concerns natural resource management. With a growing global population and the threat of climate change, issues relating to natural resource management will grow in importance with time. One fundamental aspect of natural resource management is how people perceive and value the environment. The value that is ascribed to natural resources will be one of the determinants in the choices that people face in regards to their management. A wide range of approaches have been suggested to approach environmental values. This thesis focuses on analys-ing the assessment of environmental values under different circumstances and needs. This is done by exploring the ways various theories have and can be used to approach natural resource valuation in different wetland management situations in Kenya. In the developing world the value of natural resources can, theoreti-cally, be seen as even higher than in the developed world, due to poor peoples’ direct dependency on their natural resources and the ecosystem services and goods that they provide. The point of departure in this thesis is six wetland areas with different management strategies and with multiple users. It examines how local communities, governmental authorities, industries and tourists perceive the value of the wetlands. By applying an arena perspective, that emphasises the need of interdisciplinarity, this thesis discusses the economic value of the environment and applies other methods such as, emergy analysis, stakeholder analysis, cultural theory and risk analysis, to enrich the valuation of environment.
Factors influencing the spatio-temporal dynamics of plankton communities in small tropical lakes ... more Factors influencing the spatio-temporal dynamics of plankton communities in small tropical lakes are not well-understood. This study assessed plankton communities in response to spatial (six sampling sites) and seasonal (wet vs. dry seasons) changes in environmental variables in Lake Kanyaboli, a small satellite lake on the northern shores of Lake Victoria, Kenya. Water quality variables, including pH, conductivity (EC), dissolved oxygen (DO), temperature, Secchi depth (SD), nitrates (NO3-), nitrites (NO2-), ammonium (NH4+), soluble reactive phosphorus (SRP), total nitrogen (TN), total phosphorus (TP), and chlorophyll-a(Chl-a), were monitored monthly at six sites spread throughout the lake for 1 year. Phytoplankton and zooplankton samples were collected and analyzed for taxon composition and abundance. Two-way ANOVA showed no significant interaction between site and season for all variables. Likewise, there were no significant spatial differences for all variables except Chl-a. At-t...
Lakes & Reservoirs: Science, Policy and Management for Sustainable Use, 2022
Small waterbodies are the most threatened freshwater habitats because of the large ratio between ... more Small waterbodies are the most threatened freshwater habitats because of the large ratio between their size and the catchment they drain. The present study assessed the current and historical changes in the physical, chemical and biological variables of Lake Kanyaboli, a satellite lake on the northern shores of Lake Victoria in western Kenya. Primary and secondary data on pH, electrical conductivity (EC), dissolved oxygen (DO) concentration, temperature, Secchi depth (SD), and nitrate (), nitrite (), ammonium (), soluble reactive phosphorus (SRP), total nitrogen (TN), and total phosphorus (TP) and chlorophyll‐a (Chl‐a) concentrations were utilized in the present study. The results indicated Secchi depth and chlorophyll‐a were the most erratic of all the analyzed environmental variables studied, exhibiting a range of 0.69 ± 0.29–0.87 ± 0.34 m and 9.03 ± 0.81–34.97 ± 3.36 µg/L respectively. Two‐way ANOVA yielded no significant interactions between sampling sites and seasons for all th...
The purpose of the study was to investigate the potential use of diatoms as biological monitors o... more The purpose of the study was to investigate the potential use of diatoms as biological monitors of environmental quality in Urban R. Sosianiin view of diatom distribution being affected by chemical, biological and physical characteristics of an aquatic system. In determination of Abundance, distribution and diversity of diatoms in relation to changing water quality variables, diatoms from benthic substrate in the riffle, littoral and the run with physical and chemical data were collected for a duration of six months from four strategically located sites covering a variety of anthropogenic activities along the river. Water quality parameters for instance total nitrogen whose changes are accounted for by the changing human activities but affecting diatom population were studied. During the study, a total of 9 diatoms genera unevenly distributed along the river were identified. In the upstream, the highest species diversity and relative abundance at 36.19% were recorded reducing to a r...
Globally, anthropogenic activities continues to pose wide spread pollution into the aquatic ecosy... more Globally, anthropogenic activities continues to pose wide spread pollution into the aquatic ecosystems such as rivers. This study set out to assess the sensitivity of Chironomus species to justify their use in monitoring of riverine ecosystems in the Lake Victoria Basin, Kenya. Chironomid midges were sampled from upstream and downstream of paper mill factory in the River Nzoia and sugar cane factory in the River Mbogo for toxicity tests in the laboratory. In the laboratory, midges were exposed to different dilutions of paper-mill factory effluents and sugar cane factory effluents. They were observed for mortality after every one hour for 24 hours and in case of any mortality, the dead midge was removed and counted. Sensitivity was then calculated as a percentage of the total number that died over the total midges exposed for each test. Results for all the tests were evaluated for variability among treatment effects and control using analysis of variance (ANOVA). There were significa...
The Lake Victoria Basin (LVB) is a global hotspot of aquatic biodiversity, but aquatic ecosystems... more The Lake Victoria Basin (LVB) is a global hotspot of aquatic biodiversity, but aquatic ecosystems are under threat from multiple stressors. Most studies on fish have focused on Lake Victoria, while patterns of fish diversity, distribution, and assemblage structure in influent rivers remain poorly understood. To assess threats and conservation status of riverine fishes, we used sampling surveys and searches of published and gray literature to compile data on diversity, distribution, and abundance. In total, 72 fish species were found to inhabit Kenyan rivers and associated wetlands and lakes (excluding Lake Victoria). Low‐order streams (first to third order) in headwaters of rivers are species‐poor and dominated by small‐bodied cyprinids (Enteromius spp.) and clariids (Clarias spp.). A small number of fishes are endemic to rivers, and species turnover across river basins is low. Species dominance is high, with 10 species accounting for >90% of all individuals and weights. Two cypr...
King’wal wetland, at the upper catchment of Lake Victoria, is undergoing anthropogenic disturbanc... more King’wal wetland, at the upper catchment of Lake Victoria, is undergoing anthropogenic disturbances which degrade its health. In this study, the wetland's health was assessed using water quality parameters and wetland macrophytes, sampled monthly at five stations from November 2010 to February 2011, and the health was evaluated using the Plant Index of Biotic Integrity. Mean dissolved oxygen and biological oxygen demand were significantly different among the stations (F = 10.67, p = 0.000 and F = 10.12, p = 0.000, respectively). Correlation matrix in principle component analysis for stations and the two mean measurements were negative in stations 3, 4 and 5 with component 1 at 62.3% variance and component 2 at 33.9% variance, and positive for mean TN and TP in the same stations indicating a nutrient rich environment. Anthropogenic activities including agriculture, livestock grazing, human settlement and urbanization were the main threats to the health of King’wal wetland. The in...
The study was conducted in Lake Baringo, Kenya, and determined quantitative relationships between... more The study was conducted in Lake Baringo, Kenya, and determined quantitative relationships between water‐level changes, water quality, and fishery production for purposes of evidence‐based lake basin management. Long‐term data on water level (1956–2020), water quality (2008–2021), and fisheries yields (1982–2021) from Lake Baringo were analysed using a combination of statistical methods. Linear and waveform regression analyses were used to describe patterns of lake‐level fluctuations over time, while Pearson's correlation was applied to determine the concordance of lake level changes with water quality parameters, landings, and condition of fish species. Principal components analysis (PCA) results grouped the study period into different years based on annual water quality variable levels. Locally weighted scatter plot smoothing (LOWESS) analysis showed the annual lake level amplitude declined over time with peak values in 1964 (8.6 m) and 2008 (9.4 m). The waveform regression sig...
Lakes & Reservoirs: Science, Policy and Management for Sustainable Use, 2021
Lacustrine and riverine ecosystems provide important goods and services, including being habitats... more Lacustrine and riverine ecosystems provide important goods and services, including being habitats for aquatic biodiversity, local micro‐climate moderation and a source of economic livelihoods for riparian communities. At the same time, however, they fact continuing anthropogenic and natural threats that can affect their water quality, ecological integrity and biodiversity. The present study focused on assessing spatio‐temporal variations in water quality and trophic status of Lake Baringo, a Ramsar site in Kenya. A number of physicochemical parameters, including nutrient loads, trophic status and organic pollution indices, were evaluated for the lake from water samples collected from March 2008 to December 2020. The results of the present study indicated five parameters (turbidity, fluoride, , total phosphorus and DO) exceeded the permissible limits for drinking water based on WHO standards. The water quality index (WQI) values ranged between 556.04 and 693.54, being well above the ...
Conservation and Rehabilitation of Lake Kanyaboli Wetland, Kenya Phillip Okoth Raburu Department ... more Conservation and Rehabilitation of Lake Kanyaboli Wetland, Kenya Phillip Okoth Raburu Department of Fisheries, Moi University, PO Box 3900 ... Fellow researchers to whom l am greatly indebted include the late Peter Ochumba, Omondi Akech, Otieno Manyalla, and technicians ...
One of the most important issues in the world, both for present and future genera-tions, concerns... more One of the most important issues in the world, both for present and future genera-tions, concerns natural resource management. With a growing global population and the threat of climate change, issues relating to natural resource management will grow in importance with time. One fundamental aspect of natural resource management is how people perceive and value the environment. The value that is ascribed to natural resources will be one of the determinants in the choices that people face in regards to their management. A wide range of approaches have been suggested to approach environmental values. This thesis focuses on analys-ing the assessment of environmental values under different circumstances and needs. This is done by exploring the ways various theories have and can be used to approach natural resource valuation in different wetland management situations in Kenya. In the developing world the value of natural resources can, theoreti-cally, be seen as even higher than in the developed world, due to poor peoples’ direct dependency on their natural resources and the ecosystem services and goods that they provide. The point of departure in this thesis is six wetland areas with different management strategies and with multiple users. It examines how local communities, governmental authorities, industries and tourists perceive the value of the wetlands. By applying an arena perspective, that emphasises the need of interdisciplinarity, this thesis discusses the economic value of the environment and applies other methods such as, emergy analysis, stakeholder analysis, cultural theory and risk analysis, to enrich the valuation of environment.
Factors influencing the spatio-temporal dynamics of plankton communities in small tropical lakes ... more Factors influencing the spatio-temporal dynamics of plankton communities in small tropical lakes are not well-understood. This study assessed plankton communities in response to spatial (six sampling sites) and seasonal (wet vs. dry seasons) changes in environmental variables in Lake Kanyaboli, a small satellite lake on the northern shores of Lake Victoria, Kenya. Water quality variables, including pH, conductivity (EC), dissolved oxygen (DO), temperature, Secchi depth (SD), nitrates (NO3-), nitrites (NO2-), ammonium (NH4+), soluble reactive phosphorus (SRP), total nitrogen (TN), total phosphorus (TP), and chlorophyll-a(Chl-a), were monitored monthly at six sites spread throughout the lake for 1 year. Phytoplankton and zooplankton samples were collected and analyzed for taxon composition and abundance. Two-way ANOVA showed no significant interaction between site and season for all variables. Likewise, there were no significant spatial differences for all variables except Chl-a. At-t...
Lakes & Reservoirs: Science, Policy and Management for Sustainable Use, 2022
Small waterbodies are the most threatened freshwater habitats because of the large ratio between ... more Small waterbodies are the most threatened freshwater habitats because of the large ratio between their size and the catchment they drain. The present study assessed the current and historical changes in the physical, chemical and biological variables of Lake Kanyaboli, a satellite lake on the northern shores of Lake Victoria in western Kenya. Primary and secondary data on pH, electrical conductivity (EC), dissolved oxygen (DO) concentration, temperature, Secchi depth (SD), and nitrate (), nitrite (), ammonium (), soluble reactive phosphorus (SRP), total nitrogen (TN), and total phosphorus (TP) and chlorophyll‐a (Chl‐a) concentrations were utilized in the present study. The results indicated Secchi depth and chlorophyll‐a were the most erratic of all the analyzed environmental variables studied, exhibiting a range of 0.69 ± 0.29–0.87 ± 0.34 m and 9.03 ± 0.81–34.97 ± 3.36 µg/L respectively. Two‐way ANOVA yielded no significant interactions between sampling sites and seasons for all th...
The purpose of the study was to investigate the potential use of diatoms as biological monitors o... more The purpose of the study was to investigate the potential use of diatoms as biological monitors of environmental quality in Urban R. Sosianiin view of diatom distribution being affected by chemical, biological and physical characteristics of an aquatic system. In determination of Abundance, distribution and diversity of diatoms in relation to changing water quality variables, diatoms from benthic substrate in the riffle, littoral and the run with physical and chemical data were collected for a duration of six months from four strategically located sites covering a variety of anthropogenic activities along the river. Water quality parameters for instance total nitrogen whose changes are accounted for by the changing human activities but affecting diatom population were studied. During the study, a total of 9 diatoms genera unevenly distributed along the river were identified. In the upstream, the highest species diversity and relative abundance at 36.19% were recorded reducing to a r...
Globally, anthropogenic activities continues to pose wide spread pollution into the aquatic ecosy... more Globally, anthropogenic activities continues to pose wide spread pollution into the aquatic ecosystems such as rivers. This study set out to assess the sensitivity of Chironomus species to justify their use in monitoring of riverine ecosystems in the Lake Victoria Basin, Kenya. Chironomid midges were sampled from upstream and downstream of paper mill factory in the River Nzoia and sugar cane factory in the River Mbogo for toxicity tests in the laboratory. In the laboratory, midges were exposed to different dilutions of paper-mill factory effluents and sugar cane factory effluents. They were observed for mortality after every one hour for 24 hours and in case of any mortality, the dead midge was removed and counted. Sensitivity was then calculated as a percentage of the total number that died over the total midges exposed for each test. Results for all the tests were evaluated for variability among treatment effects and control using analysis of variance (ANOVA). There were significa...
The Lake Victoria Basin (LVB) is a global hotspot of aquatic biodiversity, but aquatic ecosystems... more The Lake Victoria Basin (LVB) is a global hotspot of aquatic biodiversity, but aquatic ecosystems are under threat from multiple stressors. Most studies on fish have focused on Lake Victoria, while patterns of fish diversity, distribution, and assemblage structure in influent rivers remain poorly understood. To assess threats and conservation status of riverine fishes, we used sampling surveys and searches of published and gray literature to compile data on diversity, distribution, and abundance. In total, 72 fish species were found to inhabit Kenyan rivers and associated wetlands and lakes (excluding Lake Victoria). Low‐order streams (first to third order) in headwaters of rivers are species‐poor and dominated by small‐bodied cyprinids (Enteromius spp.) and clariids (Clarias spp.). A small number of fishes are endemic to rivers, and species turnover across river basins is low. Species dominance is high, with 10 species accounting for >90% of all individuals and weights. Two cypr...
King’wal wetland, at the upper catchment of Lake Victoria, is undergoing anthropogenic disturbanc... more King’wal wetland, at the upper catchment of Lake Victoria, is undergoing anthropogenic disturbances which degrade its health. In this study, the wetland's health was assessed using water quality parameters and wetland macrophytes, sampled monthly at five stations from November 2010 to February 2011, and the health was evaluated using the Plant Index of Biotic Integrity. Mean dissolved oxygen and biological oxygen demand were significantly different among the stations (F = 10.67, p = 0.000 and F = 10.12, p = 0.000, respectively). Correlation matrix in principle component analysis for stations and the two mean measurements were negative in stations 3, 4 and 5 with component 1 at 62.3% variance and component 2 at 33.9% variance, and positive for mean TN and TP in the same stations indicating a nutrient rich environment. Anthropogenic activities including agriculture, livestock grazing, human settlement and urbanization were the main threats to the health of King’wal wetland. The in...
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