Anthropogenic microparticles ingestion patterns in fish across trophic guilds in mangrove estuaries

The ingestion of anthropogenic microparticles by fish is an emerging global concern, with significant knowledge gaps in ecosystems such as mangroves. We analyzed the gastrointestinal tract contents of 736 juvenile fish representing 20 species from different trophic guilds across three estuaries, sampled during two seasons (dry and rainy), within the largest mangrove area in South America. A total of 1516 food items were identified, of which 128 (~ 10%) were classified as anthropogenic particles. Among these particles, 109 were microparticles, 18 were mesoparticles, and one was a macroparticle. Most particles were filaments (84%), predominantly blue and black, across all estuaries and seasons. The occurrence of anthropogenic microparticles averaged 26.07% during the rainy season and 21.25% during the dry season. Fish from all trophic guilds showed ingestion of anthropogenic particles. Our findings reveal the widespread presence of plastic- and textile-derived contamination in juvenile fish, even in remote mangrove ecosystems, highlighting the need for further investigation and mitigation efforts in both impacted and relatively pristine environments.