In Taiwan, fishways are widely used to mitigate longitudinal barriers in river systems. However, very few studies have evaluated the effectiveness of fishways. In this study, we developed a standardized protocol for monitoring
the performance of various fishways. We integrated data derived through upstream fish-passage surveys, biological
community assessments, and hydraulic measurements to analyze barrier effects from the perspectives of species
composition and population structure. Monitoring of 10 fishways over a 3-year period revealed that structural and
hydraulic problems, such as excessive drop height, high flow velocity, and ineffective resting zones, impeded the
movement of aquatic organisms. Considerable intersite variations were noted in species richness and composition.
Metrics such as community barrier index and body length distribution were used to measure potential barrier effects.
Our protocol supports standardized evaluation, design, and improvement of fishways and holds promise for broader
application.
Key Words : Fishway, barrier effect, performance monitoring.