Subchronic exposure to high-density polyethylene microplastics alone or in combination with chlortoluron significantly affected valve activity and daily growth of the Pacific oyster, Crassostrea gigas

Nowadays, pesticides and microplastics (MPs) are commonly found in coastal waters worldwide. Due to their widespread use, persistence toxicity, they may induce adverse effects on physiology behaviour of marine organisms such as the Pacific oyster (Crassostrea gigas). This study explored growth valve activity juvenile oysters exposed for 24 days two frequently detected pollutants Pertuis Charentais (South West, France): a herbicide (chlortoluron, 85 µg.L−1) high-density polyethylene microparticles (HDPE 20-25 µm, 112 MP.mL−1) alone or combination (cocktail condition; 97 µg.L−1 chlortoluron + 108 MP. mL−1). The recorded by using High Frequency Non-Invasive valvometer (HFNI) was characterized three parameters: number micro-closures (VMC), Valve Opening Amplitude (VOA), Duration (VOD). Additionally, daily shell rhythm were assessed. exposure MPs led significant increase VMC decrease VOD growth. showed VOA VMC. In with MPs, still increased decreased but also reduced Chronobiological analysis did not reveal any both contaminants. work highlighted high environmental concentrations Chlortoluron oyster.