Carbon stock assessment of mangrove ecosystem in Totok Bay, southeast Minahasa Regency, North Sulawesi, Indonesia

This study aims to analyze the blue carbon potential of mangrove ecosystem in Totok Bay waters, Southeast Minahasa Regency, North Sulawesi, using line transect method with 10 × 10 m2 quadrat placed seaward perpendicular to the shore. Preliminary survey observation found 3 species of mangrove, Rhizophora mucronata, Avicennia alba and Bruguiera gymnorhiza. Vegetation analysis was to determine the role of mangrove species using Important Value Index (IVI). IVI obtained was 147.47% for R. mucronata, 60.99% for A. alba, and 91.53% for B. gymnorhiza, respectively. Biomass measurements provided information on carbon stock. Data obtained was analyzed using allometric equation. Results showed that mean carbon stock of the mangrove biomass in Totok Bay was 17.1 kg MgC ha-1. Physical and chemical parameters analyses were also conducted as supporting data of carbon stock. Mean total carbon sink in mangrove sediment was 286.18 Mg ha-1. Mean blue carbon potential absorption was 193. 28 ton C ha-1. This research showed that mangrove ecosystem in Totok Bay held sufficiently high carbon stock. Nevertheless, the future study needs to be directed to carbon stock comparison with other locations in North Sulawesi.