Spatio‐temporal trends of nutrients and physico‐chemical parameters on lake ecosystem and fisheries prior to onset of cage farming and re‐opening of the Mbita passage in the Nyanza Gulf of Lake Victoria

Many large lake ecosystems are experiencing increasing eutrophication and persistent cyanobacteria‐dominated algal blooms affecting their water quality and ecosystem productivity because of widespread non‐point and point nutrient sources. Accordingly, the present study utilized data of July 2003 and January–February 2004, as well as previous measurements of nutrients and physico‐chemical variables (electrical conductivity, dissolved oxygen, temperature, pH, turbidity and chlorophyll‐a), to characterize the spatial and temporal trends, as a means of better understanding the factors influencing lake environmental conditions, as support tools for long‐term ecosystem management and for better understanding the long‐term trends and effects. Inshore gulf areas were found to represent zones of maximum nutrient concentrations, compared to the deep main lake zones, with significant inter‐parameter correlations. Phosphorus, silicon and chlorophyll‐a concentrations were significantly correlated. Water electrical conductivity was also significantly and positively correlated with soluble reactive silicon (SRSi), alkalinity hardness DO, while exhibiting a negative association with water transparency. Water turbidity and transparency, electrical conductivity, and SRSi concentrations clearly describe a gradient from the gulf into the main lake. For such a shallow gulf, these findings suggest primary productivity is influenced mainly by the availability of nutrients, light transparency and the extent of availability of resuspended nutrients. The increasing eutrophic state of Lake Victoria is a serious concern since it contributes to an increased potential of more frequent occurrences of cyanobacterial blooms, a potential public health risk to both humans and wildlife. Improved understanding of influences from previous fish species introductions and concomitant changes in indigenous fish species, increased lake basin population and anthropogenic activities, water hyacinth resurgences, sustainability of biodiversity, and current interests in cage farming, are among the major concerns and challenges facing the contemporary Lake Victoria. The trends regarding nutrients and physico‐chemical characteristics are intended to support better monitoring efforts and data to promote the lake's ecosystem services and the sustainable management of the lake ecosystem.     

The impacts of hydropower development on rural livelihood sustenance

The existing reservoirs on the River Tana (Kenya) were mainly constructed for hydropower generation, with inadequate consideration of the long-term impacts on downstream livelihoods. We investigated the impacts of the reservoirs on people's livelihoods downstream. The results showed a few positive impacts in the vicinity of the reservoirs and numerous negative impacts downstream (i.e. reduced flood-recess agriculture and floodplain pastoralism, and escalating resource-use conflicts). Inadequate stakeholders' consultation during reservoir development was also observed. We recommend a detailed basin-wide socioeconomic assessment for future reservoir developments and controlled flood release to simulate the natural flow regime, thereby restoring indigenous flood-based livelihoods while retaining sufficient reserves for power generation.     

Consumer willingness to pay for chicken welfare attributes in Kenya

Abstract

This study provides new insights on consumer preferences for chicken welfare attributes in a developing country context. Further, the inclusion of chicken transportation methods as an attribute is a useful contribution to empirical literature. Choice experiment survey data from 200 chicken consumers in Kenya were analyzed using random parameter logit model. Consumers had a positive preference for use of certified transportation, humanely slaughtered chicken and welfare labeling. However, there was a negative preference for using antibiotics in chicken production. Relative to the current price of chicken meat, consumers were willing to pay a premium of 30% for use of certified transport, 72% for animal welfare labeling, 135% for humane slaughter, 236% for nonuse of growth hormones and 40% less for chicken reared in confined systems.     

Toward a product-based typology for nature-based tourism: a conceptual framework

The traditional view of nature-based tourists as a relatively homogeneous group has been questioned, and several scholars have suggested various segmentation typologies. This paper discusses market and industry changes and notes key trends, as Fordist tourist products have been replaced by post-Fordist and neo-Fordist products, with both McDonaldization and McDisneyization developments. A range of visitor-based typologies are reviewed, and the conflict between capturing the diversity of today's nature-based tourists while offering management bodies simple tools to segment visitors, identify core groups and improve their marketing is noted. In an attempt to overcome this conflict, the paper presents a conceptual framework which focuses on nature-based tourism products instead of tourist types, therefore incorporating aspects of both the demand and supply sides of the nature-based tourism industry market. A two-dimensional matrix is suggested, linking four basic travel motivations (nature conservation, nature experience, sports/adventure and hedonistic) to four different types of tourist products (independent, à la carte, customized and standardized), giving a total typology of 16 different types. The matrix should help protected area managers to better understand tourist needs, suggest management measures and help to create more sustainable forms of tourism. Empirical testing is suggested as a next step.     

Agricultural Commercialisation and Nutrition in Smallholder Farm Households

Commercialisation of smallholder agriculture is important for rural economic growth. While previous studies have analysed effects of commercialisation on productivity and income, implications for farm household nutrition have received much less attention. We evaluate the effects of commercialisation on household food security and dietary quality with a special focus on calorie and micronutrient consumption. We also examine transmission channels by looking at the role of income, gender, and possible substitution effects between the consumption of own-produced and purchased foods. The analysis uses survey data from farm households in Kenya and a control function approach. Generalised propensity scores are employed to estimate continuous treatment effects. Commercialisation significantly improves food security and dietary quality in terms of calorie, zinc and iron consumption. For vitamin A, effects are insignificant. Commercialisation contributes to higher incomes and increased nutrients from purchased foods, but it does not reduce the consumption of nutrients from own-produced foods. Enhancing market access is important not only for rural economic growth, but also for making smallholder agriculture more nutrition-sensitive.     

Trace metal concentration in water and sediments of satellite lakes within Lake Victoria (Kenya) basin

Lakes Kanyaboli, Sare and Namboyo are three important freshwater satellite lakes in the northern region of the Lake Victoria (Kenya) basin. Lake Simbi, a small alkaline -saline crater-lake is located near the southern shoreline of the Nyanza Gulf of Lake Victoria. The three freshwater lakes provide unique aquatic habitats for the important indigenous fish species and other aquatic biodiversity, as well as serving as water resources for the surrounding communities. Surface and sediment samples were collected and examined to characterize these lake systems. Metal partitioning among the various defined geochemical phases also was determined. Based on the measured concentrations, the satellite lake waters are relatively uncontaminated with regard to Al (aluminium), manganese (Mn), zinc (Zn), copper (Cu) and chromium (Cr). Levels of most elements were below detection limits, as well as being well below the desirable drinking water guideline values proposed by the World Health Organization. The exception was the elevated iron (Fe) contents (>300 μg L⁻¹). The sediments exhibited a relatively low level of contamination with regard to heavy metals. The mean values of the measured metals in the sediments were compared to levels in adjacent Lake Victoria. The study results from these poorly-studied, and relatively unperturbed ecosystems, compared to the main body of lake Victoria, highlight their importance as conservation areas, despite the small-scale fishery activity, potential threats from human activities and their sensitivity to fluctuating environmental conditions.     

Level of Coherence Among Ethics Program Components and Its Impact on Ethical Intent

Journal of Business Ethics - Three ethics program components, a code of ethics, ethics training initiatives and ethics-oriented performance appraisal content, were examined for their relationship...     

Variations in trace elements in bottom sediments of major rivers in Lake Victoria's basin, Kenya

River sediments collected between March 1994 and January 1995 were analysed for iron (Fe), manganese (Mn), zinc (Zn), lead (Pb), copper (Cu), chromium (Cr), aluminium (Al) and cadmium (Cd) in the less than 63 μm grain‐size fraction. The river sediments were characterized by a sandy texture, with a relatively low organic matter (as percentage loss on ignition), ranging 3.5–9.6%. The metal mean range values in μg/g dry weight for the river sediments were: Mn (836–2.10 × 10⁴), Fe (1.09 × 10⁴–9.22 × 10⁴), Al (2.86 × 10³–7.77 × 10³), Zn (34–130), Cu (11–78), Cr (not detected ND–125); Pb (ND–100) and Cd (ND). Temporal variations were significant for Zn, Cr and Pb. There were no significant longitudinal differences in all the elements in rivers Nyando, Nzoia, Yala and Sondu‐Miriu, apart from sediment Fe contents. Relatively high sediment Fe, Mn, Zn, Cr and Al were observed in river Kasat. River Kasat was considered polluted with respect to Mn, Zn and Cr, which were comparatively higher than unpolluted sediments and geochemical background values. This supports similar results on surface water trace element levels. Most of the rivers drain an area of relatively similar lithological characteristics. Therefore, apart from the direct waste input into Kasat river from municipal and industrial sources, lack of specific point sources indicate lithological metal origins with localized variations. A final comparative evaluation of the river sediments’ trace metal pollution was made from the study results. The data is vital for pollution management of the lake as information about metal loadings into the lake ecosystem is lacking.     

Application of phytoplankton community structure for ranking the major riverine catchments influencing the pollution status of a lake basin

The present study demonstrates the application of a multi‐metric Phytoplankton Index of Biotic Integrity (PIBI) approach for ranking of major river catchments in the Kenyan part of Lake Victoria on the basis of their pollution status. The index utilizes water quality and zooplankton data, phytoplankton diversity, abundance and attributes, as well as literature information. The rivers were sampled from 2016 to 2018 during the wet season (March) and dry season (July). The separation power of the Mann–Whitney U test (p < .05) qualified eight discriminant metrics for phytoplankton samples into a scoring system of 1, 3 and 5, based on high, fair and slight deviation from the best site, respectively, in development of the final PIBI. The Kuja and Sondu‐Miriu rivers had the highest PIBI, signifying least pollution influence on the lake. In contrast, the Yala and Nzoia rivers exhibited the lowest PIBI, representing the catchments with a higher pollution influence on the lake. The fair to poor integrity classes for the major river catchments in the region signified a deteriorating lakescape. The present study presents the preliminary results of using phytoplankton metrics for development of the Index of Biotic Integrity (IBI) approach in the region as a decision‐making support tool for the effective management and sustainable use of water resources in the lake basin.