Abstract
Japanese-French Oceanographic Society of Japan had planned to hold the 18th Japanese-French Oceanography Symposium in 2020 to celebrate its 60th anniversary. However, this was postponed due to the COVID-19 pandemic. In 2021 a web-based symposium was available, and the 18th Japanese-French Oceanography Symposium was held between 19-23 October 2021. In order to disseminate the results obtained by the exchanges between French and Japanese researchers working on oceanography and fisheries science at this symposium to the public, Maison franco-japonaise and Japanese-French Oceanographic Society of Japan organised a public symposium on the theme of "Transforming our society facing the changing sea - Microplastics in the ocean -" with the co-organiser the Société franco-japonaise des Techniques Industrielles（SFJTI）as the Natural Science Lecture Series of Maison francojaponaise on 23 October 2021. This paper outlines the reasons for choosing this theme for the lecture, the basic knowledge of the microplastics issue and the summary of each presentation. Presenters were Dr François Galgani of Ifremer, Dr Katsunori Fujikura of JASMTEC, Dr Sylvain Agostini University of Tsukuba, Ms Cristina Barreau of Surfrider Foundation Europe, two high school students and Teacher Mr Takashi Inoue of Sanyo Gakuen Juniro and Senior High School and Professor Tadahisa Iwata of SFJTI/the University of Tokyo.
