Assessment of Blue Carbon Stock of Mangrove Ecosystem in Telok Bangko Bontang

Abstract Mangroves have high primary productivity so they are known as good carbon storage and absorbers (carbon sequestrators). This ability plays a very important role in the regulation of climate mitigation because the ability of mangrove sequestrators can be utilized to absorb CO 2 anthropogenic emissions. Telok Bangko, Loktuan Village, North Bontang, East Kalimantan is an area that has a mangrove ecosystem area, but is also surrounded by industrial areas and settlements. For this reason, this study aimed to assess the mangrove tree species, information on biomass, potential carbon stocks, and CO 2 absorption values at that location. Sampling was carried out using the crossed quadrant transect method. At each location the transect was carried out four times. Each transect has four crossed quadrants measuring 10 m x 10 m. In each quadrant, species identification was carried out and then the circumference of the trunk at breast height (Diamter at Breast Height) for mangrove trees (diameter > 4 cm) was measured using a tape measure. Calculation of estimated stored biomass in mangroves using allometric equations using DBH data. Next, estimates of carbon stocks and carbon uptake are calculated. These results will be presented quantitatively descriptive. From this study, 11 species were found, namely Rhizophora mucronata, Avicennia marina, Sonneratia alba, Sonneratia ovata, Derris trifoliata, Ceriops tagal, Lumnitzera racemosa, Xylocarpus granatum, Terminalia catappa, Thespesia populnea , and Wedelia biflora . The results of estimating the carbon stock of the mangrove ecosystem in Bangko Bay were 2236.36 tonnes/ha with a biomass value of 4819.74 tonnes/ha. While in the HGB area, the results of carbon stocks were 2980.48 tonnes/ha with a biomass value of 6423.44 tonnes/ha. Estimated mangrove CO 2 absorption in Bangko Bay was 8207.44 tons/ha. Meanwhile, mangrove CO 2 absorption in HGB land was 10938.35 tons/ha.