Human impacts on global freshwater fish biodiversity

No waters left untouched We are increasingly aware of human impacts on biodiversity across our planet, especially in terrestrial and marine systems. know less about fresh waters, including large rivers. Su et al. looked such systems globally, focusing several key measures fish biodiversity. They found that half all river have been heavily affected by activities, with only very tropical basins receiving the lowest levels change. Fragmentation non-native species also led to homogenization rivers, many now containing similar fewer specialized lineages. Science , this issue p. 835