Abundance, provenance, and characteristics of plastic beverage bottles in human settlements and on beaches of the Latin American Pacific region: a citizen science study

Plastic pollution is a global issue affecting both urban and natural environments. On coastlines, bottles and loose caps, either locally sourced or carried by ocean currents, represent a major share of this pollution. Identifying their sources is essential for developing measures to reduce and prevent this environmental threat. In this study, citizen scientists sampled plastic beverage bottles and loose caps, using product information to determine their abundance, provenance, and characteristics across 38 human settlements, 92 continental beaches, and 15 island beaches spanning ∼12,000 km of coastline in 10 Latin American Pacific countries. Human settlements and beaches in Central American countries had higher bottle pollution, driven mainly by high beverage consumption and deficiencies in waste management. Of the items with identifiable origin, 59 % came from within the Latin American Pacific countries. Most items found in human settlements and on continental beaches were from national sources, but Central American beaches had a higher contribution from other countries. The latter are likely transported by ocean currents, as also indicated by a high frequency of bottles with high-to-medium wear, epibionts, and older age. Island beaches had more plastic bottles from Asia, likely dumped from ships. Among all analyzed items, 26 % were manufactured by The Coca-Cola Company, followed by PepsiCo and the Aje Group. Since locally operated production plants of multinational companies and single-use individual-sized bottles are the main contributors to this type of littering, shifting to reusable bottles with a standardized format across the region could substantially reduce plastic pollution along Pacific shorelines. • Study engaged ∼1000 volunteers and 74 institutions from 10 Latin-American countries. • Bottle pollution was higher on beaches and in cities of Central American countries. • ∼60 % of the bottles found on streets and beaches originated from local producers. • Island beaches receive many Asian bottles, likely from ships and ocean currents. • Switching to standardized reusable bottles could reduce plastic pollution regionally.