Assessment of the distribution and conservation status of non-haplochromis fish species in Uganda.

Abstract

Assessing the conservation status of species according to their extinction risk is a major step in conservation planning and resource prioritization. To date, most of the assessments have been conducted on global level; yet, most conservation efforts are best conducted at national or local levels. Also, the global assessments often do not fit individual countries whose biodiversity may have unique threats that are specific and distinct from those at the global level. Elsewhere, this problem has been addressed by developing national red lists; in Uganda, this approach is also taking root, except that it has only focused on terrestrial biota, with limited attention to freshwater biodiversity. To address this gap, this study used species occurrence data, integrated with expert knowledge and literature, to revise the list and distribution of non-Haplochromis fish species native to Uganda, determine the national range of these fishes relative to the global range, and assess the extinction risk of these fishes at national level. The study showed that at least 110 non-Haplochromis fish species, belonging to 11 orders, 21 families, and 48 genera exist in Uganda. Species diversity was higher in large water bodies than small waterbodies, which is expected due to diverse habitats in the former, although it could also be attributed to sampling bias with more studies focusing on large waterbodies than small water bodies. The geographical range for 51 fish species (46% of the total number of species) was greater than 50% of the global range, suggesting that they are geographically restricted and are at a higher extinction risk. In terms of conservation status, 31 species (28%) were threatened with extinction at the national level compared to 10 species (9%) which were listed as threatened at global level as of 2021. This variation between national and global assessments suggests that the conservation status for fish species can differ, irrespective of geographical restrictedness of the species. Elsewhere, studies have shown that this scenario is likely to be abated by ensuring flow of information and data between the two assessment frameworks. The data and information from this study can, therefore, be used to improve the global assessments. In addition, this study highlights areas where surveys should be enhanced to improve our knowledge of the distribution and occurrence of the non-Haplochromis fish species. For the ease of future assessments, it is important that baseline data collection is prioritized in areas or basins where there are no occurrence records or where species are listed as Data Deficient.