This is a study of the changing status of the Ombeyi wetlands in Kisumu County, Western Kenya, an... more This is a study of the changing status of the Ombeyi wetlands in Kisumu County, Western Kenya, an area used for crop production and grazing livestock, as well as providing ecological services and supporting local livelihoods through resources such as papyrus products, fish, and water supply. The increased demand for agricultural commodities has put pressure on the Ombeyi wetlands due to its high agricultural productivity at relatively low costs. The chapter describes the pressure building up due to commercialization of agriculture (rice, sugar cane), the introduction of new and profitable but environmentally disadvantageous crops (such as arrowroot) and the resulting problems. Due to tedious work and the high cost of operation in rice production and poor markets for rice some farmers have shifted to growing other crops with better markets such as sugarcane and arrowroots. Arrowroot cultivation has led to water use conflicts, declining rice yields and low soil fertility due to poor agronomic practices. Based on team-fieldwork findings, the chapter demonstrates the need for integrating sustainable wetland management and agriculture in Ombeyi regarding wetland hydrology, ecology and socio-economics in order to avert the degradation of the wetlandsand maintain the delicate balance between wetland ecological processes and local livelihoods in the Ombeyi watershed.
A macroinvertebrate-based Index of Biotic Integrity (M-IBI) was developed to monitor ecological i... more A macroinvertebrate-based Index of Biotic Integrity (M-IBI) was developed to monitor ecological integrity of the Nyando River and its tributaries. Macroinvertebrates were sampled with a scoop net between September and December 1999 from 12 stations selected to correspond with different human activities in the catchment. The samples were hand sorted in the field, preserved in 70 % alcohol before transportation to the laboratory for identification and counting. The stations were grouped into three condition categories (reference, moderate and impaired) according to the level of water and habitat quality. Twenty metrics representing the structural and functional organization of macroinvertebrates were evaluated for range, response to disturbance and stream size differences and redundancy with each other. Ten metrics met the test criteria and were used to provide the final scores for developing the M-IBI. Metrics values at both reference and impaired sites were used to establish the sco...
Journal of ecology and the natural environment, 2015
Wetlands support livelihoods of communities living around them as in the Nyando Papyrus Wetland i... more Wetlands support livelihoods of communities living around them as in the Nyando Papyrus Wetland in Kenya. The Nyando Papyrus Wetlands provide multiple resources hence there are multiple uses and users who often overlap spatially and seasonally causing conflicts. More claims are being exerted on these wetland resources from different sides and institutional levels with different actors. The actors involved refer to various legal systems and mechanisms, and frequently create new hybrid law as in the case in the Nyando papyrus wetlands. These institutions, in various degrees of transformation, still have an important role in determining how resources are used. The objective of this study is to find out about the institutions affecting wetland resource use in the past and in the present and to determine the dynamics of specific natural resource-related institutions in four sub-locations in the Nyando Papyrus Wetlands, Kenya. The study shows that there is legal pluralism in the Nyando We...
We studied the oviposition site preference and egg hatchability of Anopheles gambiae Giles with w... more We studied the oviposition site preference and egg hatchability of Anopheles gambiae Giles with water collected from farmlands, forests, and natural wetlands. Water types significantly affected oviposition preference. Mosquitoes deposited significantly more eggs in rainwater in both the dry and wet seasons than waters from forests and wetlands, suggesting that An. gambiae prefers water with few impurities for oviposition. In the dry season, An. gambiae females also deposited significantly more eggs in waters from farmlands than those from forests and natural wetlands, but these differences were not statistically significant during the wet season. In both indoor and natural conditions, egg mortality in natural wetland habitats was significantly higher than in farmland habitats. The average water temperature in natural wetland habitats was significantly lower than farmland habitats in the natural conditions, but it remained the same under indoor experimental conditions, suggesting that factors other than water temperature play an important role in egg hatchability. Together with the findings from previous studies on the effects of land cover on larval survivorship, our results support the hypothesis that variations in habitat conditions induced by different land cover types contribute to the heterogeneous spatial distribution of An. gambiae larvae in the western Kenya highland.
Length frequency data collected from 1998 to 2001 from commercial landings was used to estimate a... more Length frequency data collected from 1998 to 2001 from commercial landings was used to estimate asymptotic length (L∞), growth coefficient (K), mortality (Z, F, M), growth performance index (φ ′) and exploitation rate (E) of Oreochromis niloticus from the Nyanza Gulf of Lake Victoria, Kenya. Studies on the diet of O. niloticus collected by demersal trawl and seining between 1998 and 2000 were also conducted. Length frequency data were analyzed using the FISAT software (an FAO-ICLARM Stock Assessment Tool package). The L∞ had a mean value (± S.D) of 58.78 ± 2.42 cm TL, K of 0.59 ± 0.05 yr− 1, Z of 2.16 ± 0.40 yr− 1, M of 1.00 ± 0.06 yr−1, F of 1.12 ± 0.34 yr−1, E of 0.48 ± 0.11 and φ ′ of 3.31 ± 0.04. Length at first entry into the fishery (L50) was observed at 26.18 ± 12.50 cm TL. Recruitment occurred throughout the year, with two peaks corresponding with the rainy seasons. A comparison with previous studies in the gulf indicates that O. niloticus is now caught at a smaller mean siz...
CROSS CUTTING ISSUES IN PAYMENT FOR ENVIRONMENTAL SERVICES... 59
The Mt Elgon ecosystem straddles the frontier between Kenya and Uganda and a major catchment for ... more The Mt Elgon ecosystem straddles the frontier between Kenya and Uganda and a major catchment for Lake Victoria, the Nile River system and Lake Turkana. It supplies a range of ecosystem goods and services to over 2 million people in Kenya and Uganda. Most of the people are poor, and place tremendous pressure on the integrity of the ecosystem. This has seen conflicts arising from competition for dwindling natural resources in fast degrading landscape. The government agencies in both countries have heightened ...
This is a study of the changing status of the Ombeyi wetlands in Kisumu County, Western Kenya, an... more This is a study of the changing status of the Ombeyi wetlands in Kisumu County, Western Kenya, an area used for crop production and grazing livestock, as well as providing ecological services and supporting local livelihoods through resources such as papyrus products, fish, and water supply. The increased demand for agricultural commodities has put pressure on the Ombeyi wetlands due to its high agricultural productivity at relatively low costs. The chapter describes the pressure building up due to commercialization of agriculture (rice, sugar cane), the introduction of new and profitable but environmentally disadvantageous crops (such as arrowroot) and the resulting problems. Due to tedious work and the high cost of operation in rice production and poor markets for rice some farmers have shifted to growing other crops with better markets such as sugarcane and arrowroots. Arrowroot cultivation has led to water use conflicts, declining rice yields and low soil fertility due to poor agronomic practices. Based on team-fieldwork findings, the chapter demonstrates the need for integrating sustainable wetland management and agriculture in Ombeyi regarding wetland hydrology, ecology and socio-economics in order to avert the degradation of the wetlandsand maintain the delicate balance between wetland ecological processes and local livelihoods in the Ombeyi watershed.
A macroinvertebrate-based Index of Biotic Integrity (M-IBI) was developed to monitor ecological i... more A macroinvertebrate-based Index of Biotic Integrity (M-IBI) was developed to monitor ecological integrity of the Nyando River and its tributaries. Macroinvertebrates were sampled with a scoop net between September and December 1999 from 12 stations selected to correspond with different human activities in the catchment. The samples were hand sorted in the field, preserved in 70 % alcohol before transportation to the laboratory for identification and counting. The stations were grouped into three condition categories (reference, moderate and impaired) according to the level of water and habitat quality. Twenty metrics representing the structural and functional organization of macroinvertebrates were evaluated for range, response to disturbance and stream size differences and redundancy with each other. Ten metrics met the test criteria and were used to provide the final scores for developing the M-IBI. Metrics values at both reference and impaired sites were used to establish the sco...
Journal of ecology and the natural environment, 2015
Wetlands support livelihoods of communities living around them as in the Nyando Papyrus Wetland i... more Wetlands support livelihoods of communities living around them as in the Nyando Papyrus Wetland in Kenya. The Nyando Papyrus Wetlands provide multiple resources hence there are multiple uses and users who often overlap spatially and seasonally causing conflicts. More claims are being exerted on these wetland resources from different sides and institutional levels with different actors. The actors involved refer to various legal systems and mechanisms, and frequently create new hybrid law as in the case in the Nyando papyrus wetlands. These institutions, in various degrees of transformation, still have an important role in determining how resources are used. The objective of this study is to find out about the institutions affecting wetland resource use in the past and in the present and to determine the dynamics of specific natural resource-related institutions in four sub-locations in the Nyando Papyrus Wetlands, Kenya. The study shows that there is legal pluralism in the Nyando We...
We studied the oviposition site preference and egg hatchability of Anopheles gambiae Giles with w... more We studied the oviposition site preference and egg hatchability of Anopheles gambiae Giles with water collected from farmlands, forests, and natural wetlands. Water types significantly affected oviposition preference. Mosquitoes deposited significantly more eggs in rainwater in both the dry and wet seasons than waters from forests and wetlands, suggesting that An. gambiae prefers water with few impurities for oviposition. In the dry season, An. gambiae females also deposited significantly more eggs in waters from farmlands than those from forests and natural wetlands, but these differences were not statistically significant during the wet season. In both indoor and natural conditions, egg mortality in natural wetland habitats was significantly higher than in farmland habitats. The average water temperature in natural wetland habitats was significantly lower than farmland habitats in the natural conditions, but it remained the same under indoor experimental conditions, suggesting that factors other than water temperature play an important role in egg hatchability. Together with the findings from previous studies on the effects of land cover on larval survivorship, our results support the hypothesis that variations in habitat conditions induced by different land cover types contribute to the heterogeneous spatial distribution of An. gambiae larvae in the western Kenya highland.
Length frequency data collected from 1998 to 2001 from commercial landings was used to estimate a... more Length frequency data collected from 1998 to 2001 from commercial landings was used to estimate asymptotic length (L∞), growth coefficient (K), mortality (Z, F, M), growth performance index (φ ′) and exploitation rate (E) of Oreochromis niloticus from the Nyanza Gulf of Lake Victoria, Kenya. Studies on the diet of O. niloticus collected by demersal trawl and seining between 1998 and 2000 were also conducted. Length frequency data were analyzed using the FISAT software (an FAO-ICLARM Stock Assessment Tool package). The L∞ had a mean value (± S.D) of 58.78 ± 2.42 cm TL, K of 0.59 ± 0.05 yr− 1, Z of 2.16 ± 0.40 yr− 1, M of 1.00 ± 0.06 yr−1, F of 1.12 ± 0.34 yr−1, E of 0.48 ± 0.11 and φ ′ of 3.31 ± 0.04. Length at first entry into the fishery (L50) was observed at 26.18 ± 12.50 cm TL. Recruitment occurred throughout the year, with two peaks corresponding with the rainy seasons. A comparison with previous studies in the gulf indicates that O. niloticus is now caught at a smaller mean siz...
CROSS CUTTING ISSUES IN PAYMENT FOR ENVIRONMENTAL SERVICES... 59
The Mt Elgon ecosystem straddles the frontier between Kenya and Uganda and a major catchment for ... more The Mt Elgon ecosystem straddles the frontier between Kenya and Uganda and a major catchment for Lake Victoria, the Nile River system and Lake Turkana. It supplies a range of ecosystem goods and services to over 2 million people in Kenya and Uganda. Most of the people are poor, and place tremendous pressure on the integrity of the ecosystem. This has seen conflicts arising from competition for dwindling natural resources in fast degrading landscape. The government agencies in both countries have heightened ...
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