India, Nov. 3 -- Sometimes the best news about nature can show up in tiny traces. NOAA Fisheries says scientists have found signs that river herring are using habitat in Maryland's Patapsco River that had been closed to them. The turning point came with the removal of the large dam in 2018. Years later, tiny traces of DNA and two adult fish show herring finding their way back. It's a small but hopeful sign that rivers can recover if we clear the way.

The Bloede Dam was located on the Patapsco River near Baltimore. For over 100 years, it was the first obstacle that fish met when swimming upstream from the Chesapeake Bay. The old dam had also been a significant threat to public safety for many years, officials say. In 2018, NOAA and partne...