Freshwater Fish Assemblages Across Protected Areas in South Africa: A Baseline for Biodiversity Conservation and Invasion Surveillance

Abstract

ABSTRACT Protected freshwater areas often fail to conserve fish biodiversity when they exclude catchment connectivity and invasion pathways. This study aimed to inventory freshwater fish species across six protected areas in South Africa and examine patterns in assemblage composition across different waterbody types, biogeographic settings and the occurrence of non‐native species. Fish surveys were carried out across six protected areas in South Africa. A total of 29 species (> 3400 individuals) from 12 families were recorded. Species richness varied among sites, with Kruger National Park sites recording the highest richness (22 species), followed by Barberton Nature Reserve (18 species), Songimvelo Nature Reserve (7 species) and the South African National Biodiversity Institute sites (5 species). The lowest species richness was recorded at Ohrigstad and Skertspruit Nature Reserves, each with only 2 species. Assemblages reflected regional biogeography, connectivity and habitat conditions, including rheophilic upland taxa and lowland omnivores and grazers. Threatened native species included Chiloglanis bifurcus , Anguilla mossambica and Oreochromis mossambicus . Only one non‐native species, Xiphophorus helleri , was detected and confined to an urban‐facing botanical garden site.