Fifty years of environmental policies like the Clean Water Act have successfully restored freshwater ecosystems, a new study finds. Analyzing data from 1970 to 2023 across seven major U.S. river basins, researchers linked falling heavy metal levels to the expansion of 71 fish and 171 insect species.

Fifty years of environmental policies like the Clean Water Act have successfully restored freshwater ecosystems, a new study finds. Analyzing data from 1970 to 2023 across seven major U.S. river basins, researchers linked falling heavy metal levels to the expansion of 71 fish and 171 insect species.