Something is amiss in our global world water supply: Striped bass are succumbing to flesh-eating bacteria in Chesapeake Bay; seabird chicks are starving in Hawai‘i; coral reefs are weakening under a growing assault of invisible contaminants and an increasing variety of aquatic animals are showing signs of developmental disorders. Experts and citizens are racing to find clues to the causes—and the solutions. Find out how we all can make a difference.