Microplastics in Brazilian coastal environments: a systematic review

Abstract

This systematic review aimed to evaluate the current scenario of research on microplastics (MPs) in Brazilian coastal environments, considering beaches and also environments not yet reported in previous reviews, such as estuaries, mangroves, and reefs. Five databases were consulted, and 102 articles on the subject published between 2018 and 2023 were selected. The universities and research institutions that most published in this period were from the Southeast region (37.3% of the articles), followed by the Northeast region (34.3%). Universities in the states of Rio de Janeiro (15.7%) and Pernambuco (15.7%) lead the number of publications, followed by São Paulo (11.8%), Rio Grande do Sul (11.8%), and Espírito Santo (7.8%). About the coastal environments studied, 70% of the studies evaluated the presence of MPs on beaches, 26% on mangroves, 2% on estuaries, and 2% on coral reefs. Studies that evaluated its presence in marine biota corresponded to 43% of the articles, sediment (42%), and water (14%). The most studied organisms were bony fish (42%), bivalves (17%), crustaceans (7%), seabirds (7%), turtles (7%), and microfauna (5%). Despite growing, the distribution of study locations is still uneven and not related to the length of the coastline of each state. As for the origin, the works compiled in this study infer that the main sources of PMs are tourism, fishing, and river discharge, while the action of waves and winds contributes to the dispersion of these particles to less urbanized beaches and remote locations.