Abstract

The global decline of eel populations due to habitat fragmentation, pollution, parasites, and overexploitation has driven existing management efforts. However, assessing the conservation value of fish within local aquatic ecosystems is essential for informed policy support and requires further evaluation. This study evaluated conservation values in local ecosystems by examining fish diversity, migratory patterns, endemism, and the International Union for Conservation of Nature (IUCN) status. Eels and sympatric fish were monitored in the Athi and Ramisi Rivers from April 2021 to May 2022 using glass and double fyke nets. Fish diversity and occurrence data, combined with Likert-scored data on migration, IUCN status, endemism, and ecological importance, were analyzed and compared using one-way ANOVA. Results indicated significantly higher fish diversity (df = 2856, t = 22, p < 0.05) in Ramisi (0.16 ± 0.003) compared to Athi (0.09 ± 0.001), with downstream sites harboring significantly higher diversity (F = 205, p < 0.05). Among eels, Anguilla mossambica (0.67 ± 0.003), Anguilla bengalensis, and Anguilla bicolor (0.631 ± 0.001) exhibited the highest conservation ranks due to their elevated IUCN status and migratory behavior compared to sympatric fish species. Ramisi had a notably higher conservation score (0.46 ± 0.002) than Athi (0.42 ± 0.001) (df = 2473, t = 17, p < 0.05). The study highlights the importance of composite metrics, incorporating endemism, migration, and IUCN status over individual species data, advancing the understanding of Kenyan river conservation and contributing to global aquatic habitat management.

Key words: Conservation value, ecological importance, endemism, invasive species, International Union for Conservation of Nature (IUCN), migratory lifestyles.