Analyzing the origins of allochthonous marine debris in protected area: The Fishermen’s village as a case study

Abstract

The study area is one of the world’s largest contiguous mangrove system and is located within a Protected Area that includes key ecosystems such as dunes, mangroves, restinga, and estuaries. This study hypothesizes that allochthonous marine litter found in the region are primarily the result of illegal dumping from ships, and that the presence of older bottles is influenced by coastal dynamics. To test this hypothesis, ten campaigns were made between April 2023 and January 2024, during spring tides over an area of 75,000 m². A total of 712 items were collected, 98 % of which were plastic bottles. Of these, 664 had identifiable brands from 41 countries across Africa, the Americas, Asia, and Europe. The presence of allochthonous waste is largely linked to illegal ship discharges, as indicated by the age and state of the bottles. Over 63 % of the collected bottles were new (> 2022), with the primary sources being China and Mauritania. Additionally, the absence of animal bite marks and the low occurrence of epibiontic organisms (only 8 %) further support this conclusion. Monthly analyses showed that during strong winds and low rainfall, debris could become buried in sediment in dune and restinga areas. Conversely, during periods of heavy rainfall or high hydrodynamic energy, erosion exposes older debris, explaining the presence of older bottles, though in smaller quantities. The lack of waste management services on Amazonian beaches within protected areas exacerbates debris accumulation, posing significant environmental challenges and negatively impacting the quality of life of traditional communities.