New Delhi, July 29 -- THE MIGHTY Yangtze, running 6,300km from the Tibetan plateau to Shanghai, is sometimes known as China's "mother river". Yet it was not always treated with much respect. Sewage and industrial waste were poured into its waters. Millions of tonnes of fish were dragged out. Mega-dams clogged up its channels. It was all too much for some of the Yangtze's most wondrous inhabitants. The baiji, a white-bellied, nearly sightless dolphin, is probably extinct; so is the gigantic, sword-nosed paddlefish. But not all the damage is permanent. Asia's longest river is now making a remarkable comeback.

Sweeping protection measures in place since 2021 seem to be aiding a recovery. Fish biomass (the estimated total weight of all the f...