Spatio-Temporal Impacts of Lake Victoria Water Level Recession on the Fringing Nyando Wetland, Kenya

Abstract

Nyando is the second largest and one of the most economically important wetland ecosystems fringing Lake Victoria, Kenya. Lake level fluctuations and a range of anthropogenic activities degrade its ecological integrity, reduce its area and the quality of goods and services it provides. This study investigated the impacts of spatio-temporal variations in the lake’s water levels on the wetland. Satellite images, ground truthing and semi-structured questionnaires were used to collect data on land use and community perceptions respectively. Results indicate that the shoreline receded significantly (t-stat = 5.5328; p-value < 0.0052) with the wetland area decreasing by 31 % between 1984 and 2010. Lake level recession exposed 752 ha of new land at an annual rate of 29 ha/year. The vulnerability of the wetland is worsened by the majority of respondents (60 %) being unable to associate the lake level recession with the wetland degradation. Eighty-six percent cultivate the exposed land for agricultural production with only 4 % of the respondents considering the land as ecologically sensitive and thus needing conservation. Development of a comprehensive and participatory wetland management plan, diversification of agricultural and fisheries production and introduction of ecologically sensitive alternative livelihood activities are recommended to ensure sustainable management.