Abstract: Fish integrity biotic indexes (F-IBIs) are indicators of river health status evaluation oriented to
fishes as research object. This study has developed a system of 12 F-IBIs for the upper Min River (Sichuan)
reaches, based on the Fausch-modified indexes and the fish survey data extensively collected over these
reaches, covering five aspects of the fishes, i.e. their composition, tolerance, nutrition structure, richness
index, species number, and health. Expectation and evaluation standard of these F-IBIs were specified for
the existing river status of hydropower development, and the F-IBIs were evaluated using the survey in 2011.
The results show that in the upper Min river, fish biological integrity is changing from average to poor state,
indicating a decrease in fish species. Species composition and expectations tend towards single, with exotic
species increasing and no top carnivorous. Several indexes are dropping, including age class, quantity,
growth, and physical fitness; fish resources are declining, and fish-catching individuals are smaller. All these
indicate deterioration in fish resources caused by the construction of hydropower projects in these reaches,
and thus we suggest further studies on fish pass facilities and their design and on ecological flow and
ecological regulation.