460 / 2024-09-17 15:14:26

Assessing seagrass carbon stock and sequestration in an aquaculture area of the Sumberkima Bay, Bali, Indonesia

seagrass,carbon stock,sequestration,aquaculture,Sumberkima Bali Indonesia

Seagrass meadows provide various coastal ecosystem services, one of which is carbon storage and sequestration. This ecosystem plays an essential role in climate change mitigation since they are responsible for large carbon sinks. Here, we observed the potential carbon stock and sequestration of seagrass meadow coexist with an intensive aquaculture area in the semi-enclosed bay of Sumberkima, Buleleng Regency, Bali. We performed 36 line transects on 12 stations to observe seagrass coverage and species composition. The Sentinel-2 satellite imagery data were analyzed to assess the seagrass extents. Six seagrass species were observed in the study area, namely Enhalus acoroides (Ea), Thalassia hemprichii (Th), Halophila ovalis (Ho), Halophila minor (Hm), Cymodocea rotundata (Cr), Halodule uninervis (Hu), Halophila pinifolia (Hp), and Syringodium isoetifolium (Si). Among the species, Cr is the dominant species since found in all the stations. The average seagrass cover in Sumberkima Bay ranged from 20.3 to 84.2%, covering 97.03 Ha. Using coverage-based modelled equations, the seagrass meadows in the study area have potential carbon stock and sequestration of 94.41 tC and 5.63 tC ha-1 yr-1, respectively. Below-ground carbon (BGC) showed 70.02% higher (64.60 gC/m2) compared to Above-ground carbon (AGB) which only 27.67 gC/m2 or 29.98%. This study implied that seagrass meadows in the location of intensive aquaculture activities have the potential to store and sequester carbon and need to be maintained to protect their ecosystem functions. If the activities in the bay are being further intensified in the future, attention should be paid not to suppress seagrass ecosystems above the threshold level.