Climate Change and Species Invasion Drive Decadal Variation in Fish Fauna in the Min River, China

Freshwater fishes are threatened by increasing environmental changes and human disturbances. The Min River, the largest river in Southeastern China, contains unique fish fauna for the Oriental realm. Due to environmental changes brought by forty years of economic growth, fish numbers have dramatically declined. The average taxonomic distinctness in the 1970s was significantly higher than that in 2015, while no significant differences were found in the variation in taxonomic distinctness between the two periods. Due to the river network and habitat diversity, fish fauna composition showed significant spatial differences but lower variation than the decadal variation. Precipitation was determined to be the most influential factor in determining the spatial pattern of fish fauna, followed by temperature. Species introduced for aquaculture have invaded the endemic fish community after escape and should be reconsidered in the trade-offs between economic development and ecological protection.