Presença e efeitos da poluição plástica em peixes marinhos e de água doce

The increase in plastic production and consumption in recent decades has been accompanied by a proportional increase in its disposal and accumulation in the environment, particularly in its potentially most polluting form, the microplastic (particles <5mm). The presence of this emerging pollutant in the environment invariably results in its interaction with organisms, potentially generating multiple effects on wildlife and human health. The scientific community has invested significant efforts to better understand such effects. However, some aspects are still unclear, while others are underexplored, especially at broader ecological scales involving ecosystem approaches and multiple levels of biological organization simultaneously. Studies in this context offer necessary advances to broaden the understanding of the threat of plastic pollution. Therefore, this thesis is organized into three chapters that investigate the plastic contamination in aquatic organisms, using fish as model organisms, and evaluate the potential effects of this contamination on physiological, functional and ecological aspects. Additionally, we will address the issue of food security, related to human consumption of potentially microplastic-contaminated marine species. In the first chapter, we tested whether exposure to microplastic can affect the health and performance of freshwater fishes, assessing biological factors from molecular to organismal level. In the second chapter, we conducted an in-situ experiment to test whether the presence of plastic in the environment influences the herbivory pressure of reef fishes, and consequently, their ecosystem function. And in the third chapter, we seek to estimate the degree of contamination in commercially relevant species in NE Brazil in order to point out the ecological and socioeconomic impacts of plastic pollution. With this thesis, we hope to contribute to the construction of a broader and more solid foundation regarding the impacts of plastic and microplastic on aquatic organisms and ecosystems.