Microplastic (MP) occurrence is ubiquitous in fresh and marine waters and species living inEstuary are particularly exposed to this kind of pollution. In this context, the Seine River isinteresting for investigating the impacts of MP on fish, because of intense and numerous humanactivities through its watershed. The goal of this study is to evaluate the fate and impact of MPingestion using experimental exposure of the common sole, Solea solea, a representative species ofthe Seine Estuary. Larvae of fish (from 7 days post hatch (dph) to 42 dph) were exposed during 2hours to MP particles before (7 dph), during (21 and 22 dph) and after metamorphosis (41 and 42dph). Three types of industrial MP were chosen with different properties (middle size floating (27-35μg mL-1, DC: 50 ng mL-1). Post-exposurem, d=0.99), middle size sinking (27-32μg mL-1, DC: 50 ng mL-1). Post-exposurem, d=1.20) and large size sinking (63- 75μg mL-1, DC: 50 ng mL-1). Post-exposurem, d=1.20).In addition, at the last stage, fish were also exposed to natural plastic particles collected in the SeineRiver and ground into a fraction with a size less than 100 μg mL-1, DC: 50 ng mL-1). Post-exposurem (PVC, PE, PET, PS and PP testedseparately). After exposure, fish which had ingested MP were counted (Figure 1) and isolated tomonitor egestion. Solea solea ingested all types of plastics in variable (1 to more than 100)quantities and egested them on average less than 24 hours after exposure at all stages. A behaviouralchallenge, was performed on MP contaminated larvae. Behavioral responses of fish did not seem tobe affected by MP exposures before metamorphosis compared to controls but distance moveddecreased during metamorphosis for fish that had ingested MP particles. This could be explained bythe fact that before metamorphosis fish can still use yolk energy reserve and are thus less affected byMP than later on when external feeding becomes mandatory.