To mark World Ocean Day on Thursday 8 June 2023, researchers and students from Mayotte's 3rd and 2nd year secondary school classes got together to present the results of work carried out as part of the PLASMA project: "Microplastic pollution of the Mayotte lagoon". This research was carried out throughout the 2022-2023 academic year, and was led by researchers (a sociologist and oceanographers from MIO) and teacher-researchers from the CUFR in Mayotte. The principle of the project is to combine traditional science with participatory science and to involve pupils in field surveys, whether in the environmental sciences (water sampling, analyses....) or the social sciences (field surveys, observations, interviews....). As well as raising awareness of the problem of microplastics among schoolchildren and the general public, this participatory science work is a serious contribution to the advancement of knowledge about this environment. The results, which will be presented to the general public on 8 June, will add to the data collected since 2017 by the Marine Park's waste observatory and provide guidance for the management measures that need to be taken in this area".