Fish Community Structure and Ecological Threats in the Albertine Graben, East Africa. Balancing Conservation and Economic Development

Abstract

This study assessed the fish community assemblages and potential threats to fish biodiversity within the Murchison Falls-Albert Delta Wetland System (MFADWS), a biodiversity hotspot in the Murchison Falls National Park, Albertine Graben. The MFADWS, extending from Murchison Falls to the Albert Delta in Uganda, supports diverse species, including fish, birds, reptiles, amphibians and mammals, all of which are vital to the livelihoods of surrounding communities. Sampling was conducted in three sections: upstream (Zipper), midstream (Delta) and downstream (Lake Albert) from April 2013 to March 2014 and October 2017 to September 2018. A total of 52 fish species were recorded, with the Zipper and Delta exhibiting greater diversity compared to Lake Albert. Among the recorded species, 43 were classified as Least Concern, seven as Not Evaluated, two as Data Deficient and one (Lates macrophthalmus), endemic to Lake Albert as vulnerable. The Shannon-Weaver diversity index (H′) was highest in the Zipper (3.4 ± 009), followed by the Delta (2.94 ± 0.31) and lowest in Lake Albert (2.19 ± 0.0). The higher biodiversity in the Zipper and Delta underscores the ecological significance of these protected areas. However, the study identified potential threats to the fish biodiversity, including illegal fishing, invasive aquatic weeds and the expansion of oil and gas developments in the Albertine Graben. To safeguard the region's biodiversity, strict enforcement of existing regulations, strengthened monitoring, control and surveillance measures, implementation of biodiversity action plans and protection of critical fish habitats are proposed, to balance biodiversity conservation with local livelihoods and economic developments.