Despite spending millennia exploring and traversing our planet’s oceans, they continue to hold secrets, both below and above water. While we’ve long known that discarded plastic ends up in large bodies of water, along with numerous studies on its origins, a new study adds insights to the composition and path of ocean garbage.

Published in the journal Nature Sustainability, the study, led by Marine Litter Lab at the University of Cádiz fellow Carmen Morales-Caselles, found that plastic comprises about 80 percent (±18%) of all ocean pollution.

Researchers also discovered that the type of plastic found depended on the type of environment, and for coastal plastic, on the surrounding socio-economic conditions. The prevalence of single-use items was found between the 50th and 30th longitude lines and included much of the continental US and Western Europe.