ABSTRACT This research was conducted in January 2022. Calculations the density and sampling of seagrass were carried out in Dusun Jati, Tuapejat, North Sipora District, Mentawai Islands Regency and seagrass sample analysis was carried out at the Marine Chemistry Laboratory, Faculty of Fisheries and Marine Affairs, Riau University. The objective of study is to analyze the density of seagras…