Fewer worms live in mud littered with lots of microplastics
Despite growing concerns over tiny bits of plastic filling the world’s waterways, the long-term environmental effects of that debris remain murky. Now an experiment on freshwater sediment communities exposed to microplastics for over a year helps clarify how harmful this pollution can be. Researchers embedded trays of sediment littered with different amounts of polystyrene particles — ranging from 0 to 5 percent plastic — in the bottom of an outdoor canal where bugs, snails and other critters colonized the mud. After 15 months, fewer organisms were found living in the trays with 5 percent polystyrene than in trays with less plastic, largely because fewer Naididae worms lived in the most polluted mud. The trays with 0 to 0.5 percent microplastic averaged between about 500 and 800 worms per tray, while mud with 5 percent plastic averaged fewer than 300, researchers report January 31 in Science Advances. That reduction in Naididae worms suggests that...