Contribution of fish farmers to conservation of endangered Lake Victoria Basin fish species - the case of Oreochromis variabilis and O. esculentus.

2020 ◽  
Author(s):  
Harrison Charo-Karisa ◽  
Jacob Maithya
Keyword(s):  
Growth Performance ◽  
Fish Species ◽  
Lake Victoria ◽  
Culture Conditions ◽  
Water Bodies ◽  
Lake Victoria Basin ◽  
Endangered Fish ◽  
Small Water ◽  
Course Of Action

Abstract This paper discussed the conservation efforts of fish farmers of two endangered fish species in Lake Victoria namely Oreochromis variabilis and O. esculentus. Highlights focused on the determination of their growth performance under culture conditions, assessing their suitability for aquaculture, recruiting farmers to culture the species and testing the suitability of new dams and ponds for aquaculture. Both species breed easily under culture conditions. Therefore production of the fingerlings and their subsequent stocking in ponds, small water bodies and other larger water masses, including Lake Victoria, was a course of action implemented by the fish farmers to bring about their restoration.

scholarly journals Effect of Eichhornia crassipes on coliforms load in small water bodies within Lake Victoria basin, Kenya

2015 ◽  
Vol 9 (10) ◽  
pp. 736-740
Author(s):  
Ombwa Veronica ◽  
Orwa Patrick ◽  
Mutie Alice ◽  
Omondi Reuben ◽  
Werimo Kenneth ◽  
...  
Keyword(s):  
Eichhornia Crassipes ◽  
Lake Victoria ◽  
Water Bodies ◽  
Lake Victoria Basin ◽  
Small Water ◽  
Small Water Bodies

Determination of chlorophyll content of small water bodies (kettle holes) using hyperspectral airborne data

2011 ◽  
Vol 13 (6) ◽  
pp. 912-921 ◽  
Author(s):  
Rahmatulla M. Igamberdiev ◽  
Goerres Grenzdoerffer ◽  
Ralf Bill ◽  
Hendrik Schubert ◽  
Martin Bachmann ◽  
...  
Keyword(s):  
Chlorophyll Content ◽  
Water Bodies ◽  
Small Water ◽  
Small Water Bodies

scholarly journals Assessment of the Ecological Health of Afrotropical Rivers Using Fish Assemblages: A Case Study of Selected Rivers in the Lake Victoria Basin, Kenya

2021 ◽  
Vol 2 ◽  
Author(s):  
Alfred O. Achieng ◽  
Frank O. Masese ◽  
Tracey J. Coffey ◽  
Phillip O. Raburu ◽  
Simon W. Agembe ◽  
...  
Keyword(s):  
Water Quality ◽  
Fish Species ◽  
Fish Assemblages ◽  
Lake Victoria ◽  
Principal Component ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
Lake Victoria Basin ◽  
Anthropogenic Pressures ◽  
Species Tolerance

Streams and rivers are globally threatened ecosystems because of increasing levels of exploitation, habitat degradation and other anthropogenic pressures. In the Lake Victoria Basin (LVB) in East Africa, these threats are mostly caused by unsustainable land use; however, the monitoring of ecological integrity of river systems has been hampered by a lack of locally developed indices. This study assessed the health of four rivers (Nzoia, Nyando, Sondu–Miriu and Mara) on the Kenyan side of the LVB using physicochemical water quality parameters and a fish-based index of biotic integrity (IBI). Fish tolerance ranking was derived from principal component analysis of water quality parameters, and the concept of niche breadth (NB). The relationship between fish species and water quality parameters was examined with canonical correspondence analysis, whereas community metrics and stressors were evaluated through Pearson network correlation analysis. Fish species richness, trophic structures, taxonomic composition and species tolerance were used to generate the metrics for fish-based IBI. NB showed that most of the fish species were moderately tolerant to poor water. Moderately tolerant and intolerant fish species were negatively correlated with a high level of organic loading in the Mara River. Fish-based IBI scores for the rivers ranged from 26 to 34, with Sondu–Miriu scoring the lowest. Our results show that the cumulative effect of stressors can adequately rank fish species tolerance according to the disturbance gradients and further develop regional metrics to assess river health. Despite the fact that fish communities are declining, continual management and enforcement of environmental regulations are important, with conservation and management of headwaters and low-order streams being essential while they are still species rich.

scholarly journals Land Use and Land Cover Change as an Indicator of Watershed Urban Development in the Kenyan Lake Victoria Basin

2021 ◽  
Vol 16 (2) ◽  
pp. 335-345
Author(s):  
Dancan Otieno Onyango ◽  
Christopher O. Ikporukpo ◽  
John O. Taiwo ◽  
Stephen B. Opiyo
Keyword(s):  
Land Use ◽  
Land Cover ◽  
Agricultural Land ◽  
Lake Victoria ◽  
Water Bodies ◽  
Natural Environments ◽  
Land Use Land Cover ◽  
Lake Victoria Basin ◽  
Ecological Value ◽  
Bare Land

The socio-economic and ecological value of Lake Victoria is threatened by significant regional development and urbanization. This study analyzed spatial-temporal land use/land cover changes in the Kenyan Lake Victoria basin from 1978–2018 using Landsat 3, 4-5 and 8 imagery, with a view to identifying the extent and potential impacts of urbanization on the basin. Supervised image classification was undertaken following the Maximum Likelihood algorithm to generate land use/land cover maps at ten-year intervals. Results indicate that the basin is characterized by six main land use/land cover classes namely, agricultural land, water bodies, grasslands and vegetation, bare land, forests and built-up areas. Further, the results indicate that the basin has experienced net increases in built-up areas (+97.56%), forests (+17.30%) and agricultural land (+3.54%) over the last 40 years. During the same period, it experienced net losses in grassland and vegetation (-37.36%), bare land (-9.28%) and water bodies (-2.19%). Generally, the changing landscapes in the basin are characterized by conversion of natural environments to built-up environments and driven by human activities, urban populations and public policy decisions. The study therefore recommends the establishment of a land use system that creates a balance between the ecological realm and sustainable development.

scholarly journals Retention efficiencies of halogenated and non-halogenated hydrocarbons in selected wetland ecosystem in Lake Victoria Basin

2015 ◽  
Vol 4 (2) ◽  
pp. 38-52 ◽  
Author(s):  
Shadrack Mule ◽  
Charles Nguta ◽  
Geoffrey Kamau ◽  
Gilbert Ongera ◽  
Phanice Wangila ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Mass Spectrometer ◽  
Lake Victoria ◽  
Anthropogenic Activities ◽  
Halogenated Hydrocarbons ◽  
Lake Victoria Basin ◽  
Plant Materials ◽  
Wetland Ecosystems ◽  
Percentage Retention

The determination of retention efficiencies of halogenated and non-halogenated hydrocarbon in selected wetland ecosystems in Lake Victoria basin was carried out. Qualitative and quantitative determination of the presence of residual hydrocarbons in Kigwal/Kimondi, Nyando and Nzoia wetland ecosystems using Gas Chromatography - Mass Spectrometer (GC-MS) instrument indicated the presence of residual organochlorines, organophosphorus, carbamates and synthetic pyrethroid hydrocarbons in water, sediment and plant materials. In order to compare the retention efficiencies of the wetlands, the wetland ecosystems were divided into three different sections, namely: inlet, mid and outlet. Calculations of mass balances of residual halogenated and non-halogenated hydrocarbons at the respective sections was done taking into account the partition of the studied compounds in samples of water, sediments and papyrus reed plant materials and analyzed using validated Gas Chromatography - Mass Spectrometer (GC-MS) method. From the analysis, several residual hydrocarbons namely: bendiocarb, benzene hexachloride (BHC), carbaryl, cypermethrin, decis, deltamethrin, diazinon, dieldrin, DDT, DDD, DDE, malathion, propoxur, sumithion, 5-phenylrhodanine, 1,3,5-trichlorobenzene, 1-(2-phenoxybenzyl)hydrazine were detected and quantified. The levels of the selected residual hydrocarbons in water samples were used to calculate the retention efficiencies of a specific hydrocarbon and the values recorded. Generally, River Nyando wetland recorded mean percentage retention efficiencies of 76 and 94% for dry and rainy seasons respectively; Kigwal/Kimondi wetland had seasonal mean percentage retention efficiencies of 63 to 78%. River Nzoia also had calculated seasonal mean percentage retention efficiencies of between 56 to 88%. Dry season had lower mean percentages retention efficiencies as compared to rainy season in the three wetlands of interest during the period of study. The study observed that retention efficiencies of tropical wetland ecosystems is greatly affected by its concentration within the wetland tank systems, anthropogenic activities, physical properties of the hydrocarbon, and environmental conditions among others. There are several anthropogenic activities which contributed to the presence of hydrocarbons in the wetlands and they included: agricultural, municipal, industrial and public health activities. DOI: http://dx.doi.org/10.3126/ije.v4i2.12623 International Journal of Environment Vol.4(2) 2015: 38-52

scholarly journals Assessments at multiple levels of biological organization allow for an integrative determination of physiological tolerances to turbidity in an endangered fish species

2016 ◽  
Vol 4 (1) ◽  
pp. cow004 ◽  
Author(s):  
Matthias Hasenbein ◽  
Nann A. Fangue ◽  
Juergen Geist ◽  
Lisa M. Komoroske ◽  
Jennifer Truong ◽  
...  
Keyword(s):  
Fish Species ◽  
Biological Organization ◽  
Endangered Fish ◽  
Physiological Tolerances ◽  
Multiple Levels
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