2026/05/01 by G. Glenn Wilson, Wassie Anteneh, Martin de Graaf +11 · 1 voice
Environmental Science · #Aquatic Ecosystems and Biodiversity #Aquatic Ecosystems and Phytoplankton Dynamics #Fish biology, ecology, and behavior
paper · doi:10.1002/aqc.70381
openalex publication_date 2026/05/01 · openalex created_date 2026/05/22 · openalex updated_date 2026/07/26
ABSTRACT Freshwater fish biodiversity faces immense pressures, especially in tropical developing regions where it provides critical protein and income. Effective conservation strategies require knowledge of species at scales matching their distribution and life history. Lake Tana and its inflowing rivers contain the most diverse flock of cyprinid ( Labeobarbus ) fishes globally, most of which are endemic to this ecosystem and of heightened extinction concern. We collated Labeobarbus abundance datasets from this aquatic biodiversity hotspot from 1992 to 2020 to allow spatial prioritization of future conservation actions. Percentage abundance data were compared across multiple spatial scales, between endemism and IUCN Red List categories and by proximity to weirs. The overall species contribution of endemics to assemblages was half that of those presumed nonendemics and far less for IUCN data deficient, vulnerable or endangered species than those of Least Concern status. Assemblages varied significantly between geomorphic habitats, between catchments and in relation to weirs, driven foremost by habitat‐generalists and lake‐specialists. Multiple habitats in various catchments require protection to conserve river‐dependent species, especially those at a higher extinction risk. Species designated as vulnerable or endangered were particularly associated with specific river mouths and main river channels. For freshwater fishes in which spawning aggregation and migration appear to be obligatory life‐history traits, details such as these at the scale of their distribution are essential for determining where best to implement conservation measures. Future barrier construction and fishing closures should account for patterns in Labeobarbus species segregation to minimize disruption of migratory spawning events and avoid species losses. Statement of Significance We collated 17 Labeobarbus abundance datasets from Ethiopia’s Lake Tana and its inflowing rivers and a 28‐year period. This allowed the first assessment at a whole‐of‐drainage scale of how these high‐endemicity assemblages were distributed and where best to implement conservation measures. Relative abundance of endemic species was half that of those presumed non‐endemic, and Vulnerable and Endangered species were highly segregated within and between rivers. However, sites upstream of weirs were dominated by a single habitat‐generalist species. Locating weirs and fishing closures must consider species’ uneven distributions to avoid species losses and reduced assemblage diversity. These findings contribute to a stronger understanding of this Africa‐wide genus, and provide a template for managing tropical lake fishes for improved conservation outcomes.