Fish struggle when plastic bits and pesticides team up

Scientists tested what happens when tiny plastic fibers and a common insect killer show up together in the water where young tilapia live. Over six weeks, fish exposed to both pollutants grew less and ate food less efficiently than fish exposed to just one or none at all. Their guts showed damage too—fewer mucus-making cells and shorter finger-like projections that normally help absorb nutrients. Inside the fish, three growth-related genes nearly shut down, suggesting the duo of pollutants blocks the signals that tell young fish to grow bigger.The team also noticed the problems weren’t separate; they piled on top of one another. When the data were plotted on a graph, fish that grew poorly usually had the worst gut damage and the quietest genes, all at the same time. That pattern hints the pollutants work together to stress the fish in ways they wouldn’t if left alone.