Microplastic (MP) wastes at sea poses a risk to marine organisms. These particles (<5mm) are ingested with consecutive impacts on physiology such as reproductive effects. Nanoplastics (NP) would have the ability to pass through the cell membrane causing irreversible damage. This project proposes to study the impact of MP and NP on the biomineralisation and the reproduction of the pearl oyster Pinctada margaritifera, with a focus on the quality of the pearl in a context where plastics are used extensively in aquaculture. The contamination of pearl and non-pearl lagoons will be characterized in task 1 to estimate the environmental exposure of pearl oysters. Then, the impact of MP on the pearl oyster and the quality of the pearl will be addressed in task 2, according to a realistic scenario by assessing the main functions of energy metabolism, biomineralization and reproduction, up to consequences to the next generation. Finally, in task 3, the effects of nanobeads and nanofibers, potentially more impacting, will be addressed. The results obtained will provide understanding of the effects of MP and NP in pearl oyster and estimate the risks for the pearl industry in French Polynesia.