Estimating Blue Carbon Stock: Mangrove and Seagrass Biomass Assessment in Tunda Island, Serang, Banten, Indonesia

Abstract

Tunda Island is one of the islands at the northern tip of Banten Province, with natural and well-maintained seagrass and mangrove ecosystems. Even though its location is close to an urban area, the use of aquatic resources such as fishing and cultivation is small compared to other islands. However, developing issues such as sand mining plans will undoubtedly impact the surrounding coastal ecosystems, such as mangroves and seagrass in Tunda Island. Related to their role in reducing the impact of climate change, these two ecosystems need to be protected because coastal ecosystems are ten times more effective at sequestering carbon dioxide per area than boreal, temperate, or tropical forests. Therefore, this study aimed to determine the potential of seagrass and mangrove biomass for blue carbon storage on Tunda Island as baseline data for managing small islands that are still natural. Calculation of the area of mangrove and seagrass ecosystems on Tunda Island was obtained by classifying high-resolution imagery from Unmanned Aerial Vehicle (UAV) Drones. The potential for blue carbon storage was calculated using the allometric equation on seagrass (percent cover and density) and mangroves (DBH and wood density). The results showed that Tunda Island had six species of seagrass, which were dominated by Thalassia hemprichii, and six species of mangrove, which Rhizopora apiculata dominated. Based on the results of the UAV Drone image classification, the mangrove and seagrass ecosystem area was 14 and 398 ha. After that, it can be calculated that the potential value of blue carbon stores in Tunda Island is 160,38 tons C, with the most significant carbon stock being 60% in the mangrove ecosystem biomass and 40% in seagrass biomass. These results mean that blue carbon stock in Tunda Island has a small value compared with Indonesia's average mangrove and seagrass carbon data.