Biomass and carbon storage of Sargassum sp. in Poncan Gadang Island, North Sumatera Province

One of the efforts made to reduce the increase in CO₂ is to use coastal vegetation such as macroalgae. This research was conducted in Poncan Gadang island, North Sumatera. The purpose of this research is to know the density and biomass of macroalgae Sargassum sp. and to estimate carbon storage in the macroalgae Sargassum sp. in the waters of Poncan Gadang island. The results showed that the biomass and carbon stores in Sargassum sp. are quite large and varied from 2.82 kg C m^-2, 4.80 kg C m^-2, and 4.63 kg C m^-2 in every sampling point with an average of 4.08 kg C m^-2. This means Sargassum sp. has the potential in mitigating climate change through carbon sequestration. Differences in the value of carbon stored in the biomass of Sargassum sp. are affected by biomass density and different carbon content at each sampling point due to environmental conditions.