Effectiveness of UNESCO biosphere reserves in achieving management objectives in Ethiopia: the case of Lake Tana

Abstract Biosphere reserves are established to conserve biodiversity, ensure sustainable use of natural resources, and promote the development of local communities. Over the past decade, Ethiopia has designated five distinct biosphere reserves across its national territory. The Lake Tana Biosphere Reserve, established in 2015, is located in northwestern Ethiopia and aims to conserve biodiversity and promote sustainable development. However, the effectiveness of biosphere reserves in achieving their stated objectives has not been adequately addressed. Therefore, this article aims to evaluate the effectiveness of Lake Tana Biosphere Reserve in achieving its established management objectives. Specifically, it aimed to assess and evaluate the biodiversity status and analyse the land use and land cover changes within the biosphere reserve. This was achieved by reviewing relevant published literature and analyzing land use and land cover changes in the biosphere using satellite data. Lake Tana biosphere reserve harbors 27 mammal species, 437 bird species, 28 fish species, 19 amphibian species, and 35 reptile species. However, the results of satellite image classification showed that the biosphere reserve has experienced notable changes in its land use and land cover. The most significant changes observed were an expansion of agricultural and build-up area, as well as the infestation of exotic aquatic plants (i.e. water hyacinth) covering the surface of the lake. The area of cultivated land and built-up land increased from 339,782.32 ha and 2,025.15 ha in 2014 to 343,134.32 ha and 8,124.39 ha in 2024, respectively. Similarly, 2,330.17 ha of the Lake Tana surface area was covered by water hyacinth in 2024. In contrast, there has been a significant decline in the extent of forests, water bodies, wetlands, and grazing lands within the biosphere reserve over the past decade. The integration of research findings has highlighted the importance of sustainable land management practices and effective community engagement for the conservation and preservation of the biosphere reserve. In light of this, improved management of these resources is recommended, necessitating a deeper understanding of the cause-effect relationships between anthropogenic impacts and environmental components.