By 2050, about 99.8% of the species studied will have eaten plastic, the researchers report online today in the Proceedings of the National Academy of Sciences. Consuming plastic can cause myriad problems, Wilcox says. For example, some types of plastics absorb and concentrate environmental pollutants, he notes. After ingestion, those chemicals can be released into the birds’ digestive tracts, along with chemicals in the plastics that keep them soft and pliable. But plastic bits aren’t always pliable enough to get through a gull’s gut. Most birds have trouble passing large bits of plastic, and they build up in the stomach, sometimes taking up so much room that the birds can’t consume enough food to stay healthy.