Microplastics are pieces of plastic less than 5 mm in diameter and are a global marine pollutant. A study by Stephanie Wright from the University of Exeter found that if ocean sediments* are heavily contaminated with microplastics, marine lugworms eat less and their energy levels suffer. A separate report from Mark Anthony Browne shows that ingesting microplastic can also reduce the health of lugworms because it delivers harmful chemicals, including hydrocarbons, antimicrobials, and flame retardants to them.