Anthropogenic microparticles accumulation in small-bodied seagrass meadows: The case of tropical estuarine species in Brazil

Seagrass meadows have recently been highlighted as potential hotspots for microplastic and anthropogenic microparticles (APs). This study assessed AP accumulation in shallow sediments vegetated by small-bodied seagrass species (Halodule wrightii, Halophila decipiens, and H. baillonii) and in the adjacent unvegetated area in a tropical estuary on the East Coast of South America, Brazil, over the seasonal cycle. Anthropogenic microparticles were detected in 80 % of the samples, with a mean abundance of 142 ± 140 particles kg dw (N = 80). Particles were predominantly blue (51 %), fiber (73 %), and smaller than 1 mm (80 %). We observed that seagrass sediments retained APs, although no significant variation was observed between seagrass and the unvegetated area, nor between the dry and rainy seasons. A positive correlation was found between sediment grain size and AP abundance. This study represents the first record of AP contamination in seagrasses from the Tropical Southwestern Atlantic bioregion.