Biological Connectivity in Freshwater Ecosystems: Evaluation of Spatial and Temporal Anomalies in a River Basin

Efforts to protect freshwater ecosystems, and the biodiversity that supports their essential services, are increasing globally, yet biological connectivity still receives less attention compared to physical or chemical connectivity. This study piloted a basin-scale assessment of biological connectivity in the Seomjin River basin, Korea, which recently experienced an extreme flood, using biodiversity indicators (species richness and similarity). Results show that the flood affected freshwater fish at smaller spatial scales and benthic macroinvertebrates at larger scales, while impoundments disrupted upstream–downstream biological connectivity. Expanded monitoring, standardized methods and integration with multispecies conservation will further strengthen this approach for holistic water management.