Fish are adapting to rivers shaped by dams and barriers, and that may be changing how man-made rivers function over time

For decades, river restoration has focused on returning waterways to conditions that existed before dams, weirs and large-scale human intervention. But new research suggests fish living in altered rivers may already be adapting to those environments. The findings raise a new challenge for conservationists: if fish populations are evolving in response to human-made rivers, restoring habitats alone may no longer be enough.