This paper reports on the levels of 8 organochlorine pesticide residues and metabolites in three fish species; Tilapia （Oreochromis leucostictus）. Common carp （Cyprinus carpio） and Mirror carp （Cuprinus spectacul...This paper reports on the levels of 8 organochlorine pesticide residues and metabolites in three fish species; Tilapia （Oreochromis leucostictus）. Common carp （Cyprinus carpio） and Mirror carp （Cuprinus spectacularlus） from Lake Naivasha, Kenya. p,p＇-DDT, p,p＇-DDE, p,p＇-DDD, heptachlor, heptachlor epoxide, aldrin, dieldrin and methoxychlor were analyzed in fish specimens collected from Lake Naivasha during the months of November - December in 2008. The pesticide concentrations （in ~ag/Kg, wet weight） ranged within 0.42-4.185 p,g/Kg, for Heptachlor, BDL-0.291 Heptachlor epoxide, 0.433-4.733 Aldrin, BDL -0.341 Dieldrin, p,p＇ DDT, BDL-6.691 p,p＇ DDE, BDL-27.153 p,p＇ DDD, and BDL-28.867 methoxychlor. The pesticide residue levels varied widely between and within species. C. spectacularhts showed high pesticide levels followed by C. carpio and O. leueostictus respectively; this was attributed to the trophic position and age/size of fish. The occurrences of the pesticides indicate recent use in the catchment. The mean values and ranges of residues found in fish ware below the FAO/WHO maximum acceptable limits in fish and sea food however increased monitoring is recommended to detect any changes.展开更多
Human activities in the Lake Naivasha catchments pose serious ecological threats to sustainable freshwater ecosystem management. The future hangs on the balance of economic exploitation and sustainable watershed conse...Human activities in the Lake Naivasha catchments pose serious ecological threats to sustainable freshwater ecosystem management. The future hangs on the balance of economic exploitation and sustainable watershed conservation. Water abstraction volumes, embedded water/virtual water and chemical analysis of wastewater discharges were assessed. Dissolved oxygen, temperature, Secchi disc depth, benthic organisms＇ population and pesticides used in the farms were determined. The study found that abstraction exceeds safe water yield, farms have also encroached on the riparian lands and connected to the lake through canals allowing effluents to flow directly to the lake. Benthic community populations are low at points where discharge canals enter the lake, indicating inflow of materials are toxic. Canal samples show high contaminant levels of actions for sustainable exploitation of the resource is essential. compared to other sites. Wise use of the resource and implementation The determination of ecological and water footprints are recommend.展开更多
A survey to identify constraints and design strategies to improve the camel milk and meat value chains was conducted in northern Kenya using Participatory Integrated Community Development （PICD）, Focus Group Discuss...A survey to identify constraints and design strategies to improve the camel milk and meat value chains was conducted in northern Kenya using Participatory Integrated Community Development （PICD）, Focus Group Discussions （FGD）, among other methods. In a second step, field testing of an intervention on milk and meat hygiene was carried out at household level. Survey results indicated that about 50% of marketable camel milk was not sold, 30% of marketed camel milk per annum was sold in sour state at US$ 0.13 lower that the price of a litre of fresh milk while processed meat got spoiled along the chain. Annual economic losses associated with milk spoilage were estimated at US$ 961,538.5. Preliminary findings of the field testing indicated that an additional 3 million litres of camel milk was sold in fresh state, giving an annual saving of US$ 384,615.4. Increased profitability of up to 60% compared to 30% before the intervention was reported among nyirinyiri processors. In conclusion, economic potential of the camel could be fully exploited by facilitating adoption of interventions such as hygiene, among others at all levels of the camel milk and meat value chains.展开更多
文摘This paper reports on the levels of 8 organochlorine pesticide residues and metabolites in three fish species; Tilapia （Oreochromis leucostictus）. Common carp （Cyprinus carpio） and Mirror carp （Cuprinus spectacularlus） from Lake Naivasha, Kenya. p,p＇-DDT, p,p＇-DDE, p,p＇-DDD, heptachlor, heptachlor epoxide, aldrin, dieldrin and methoxychlor were analyzed in fish specimens collected from Lake Naivasha during the months of November - December in 2008. The pesticide concentrations （in ~ag/Kg, wet weight） ranged within 0.42-4.185 p,g/Kg, for Heptachlor, BDL-0.291 Heptachlor epoxide, 0.433-4.733 Aldrin, BDL -0.341 Dieldrin, p,p＇ DDT, BDL-6.691 p,p＇ DDE, BDL-27.153 p,p＇ DDD, and BDL-28.867 methoxychlor. The pesticide residue levels varied widely between and within species. C. spectacularhts showed high pesticide levels followed by C. carpio and O. leueostictus respectively; this was attributed to the trophic position and age/size of fish. The occurrences of the pesticides indicate recent use in the catchment. The mean values and ranges of residues found in fish ware below the FAO/WHO maximum acceptable limits in fish and sea food however increased monitoring is recommended to detect any changes.
文摘Human activities in the Lake Naivasha catchments pose serious ecological threats to sustainable freshwater ecosystem management. The future hangs on the balance of economic exploitation and sustainable watershed conservation. Water abstraction volumes, embedded water/virtual water and chemical analysis of wastewater discharges were assessed. Dissolved oxygen, temperature, Secchi disc depth, benthic organisms＇ population and pesticides used in the farms were determined. The study found that abstraction exceeds safe water yield, farms have also encroached on the riparian lands and connected to the lake through canals allowing effluents to flow directly to the lake. Benthic community populations are low at points where discharge canals enter the lake, indicating inflow of materials are toxic. Canal samples show high contaminant levels of actions for sustainable exploitation of the resource is essential. compared to other sites. Wise use of the resource and implementation The determination of ecological and water footprints are recommend.
文摘A survey to identify constraints and design strategies to improve the camel milk and meat value chains was conducted in northern Kenya using Participatory Integrated Community Development （PICD）, Focus Group Discussions （FGD）, among other methods. In a second step, field testing of an intervention on milk and meat hygiene was carried out at household level. Survey results indicated that about 50% of marketable camel milk was not sold, 30% of marketed camel milk per annum was sold in sour state at US$ 0.13 lower that the price of a litre of fresh milk while processed meat got spoiled along the chain. Annual economic losses associated with milk spoilage were estimated at US$ 961,538.5. Preliminary findings of the field testing indicated that an additional 3 million litres of camel milk was sold in fresh state, giving an annual saving of US$ 384,615.4. Increased profitability of up to 60% compared to 30% before the intervention was reported among nyirinyiri processors. In conclusion, economic potential of the camel could be fully exploited by facilitating adoption of interventions such as hygiene, among others at all levels of the camel milk and meat value chains.
