When oily plastic and glass, as well as rubber, washed onto Florida beaches in 2020, a community group shared the mystery online, attracting scientists' attention. Working together, they linked the black residue-coated debris to a 2019 oil slick along Brazil's coastline. Using ocean current models and chemical analysis, the team explains in Environmental Science & Technology how some of the oily material managed to travel over 5,200 miles (8,500 kilometers) by clinging to debris.