Building Blue Carbon Projects - An Introductory Guide

8.5 Exploring Seagrass Climate Change Mitigation Potential in Thailand and Australia

One of the key Blue Carbon knowledge gaps for seagrass ecosystems is that the current scientific literature for seagrass carbon is mainly based on research from temperate areas, and extending such knowledge into tropical marine regions is vitally needed. Consequently, a study titled Nature- based climate change mitigations through management and restoration of seagrass meadows: quantifying the potential has explored seagrasses for their climate change mitigation potential at two tropical locations: the seagrass beds of Haad Chao Mai National Park, Trang Province, Andaman Sea, Thailand and Cairns Harbour, the Great Barrier Reef World Heritage Area (GBRWHA), Queensland, Australia. The study was implemented by the IUCN Global Marine and Polar Programme (GMPP) in close collaboration with the University of Technology in Sydney (UTS) with funding from the TOTAL foundation. The project supported an international PhD student from UTS, who executed the research, using both laboratory and field-based experiments and observations. This work provided insights into the carbon storage of tropical seagrasses. The project examined carbon in the sediments of pristine and degraded seagrass meadows and determined how much the loss and degradation of these systems affected their carbon storage capacity. The project showed that tropical seagrass meadows are equally important as temperate seagrass meadows for Blue Carbon storage, providing evidence that tropical living seagrasses are potentially one of the largest pools of organic carbon storage compared to global seagrass areas. This research also confirmed that the below-ground biomass of seagrasses plays a more important role as a carbon stock than the above ground parts, storing five times more carbon in the roots than in the leaves and stems. This research illustrated the first estimate of changes in the organic carbon stock stored in sediment after seagrass loss. Estimation of carbon stock showed that the carbon value of degraded sediment was five times lower than sediment from pristine seagrass beds. These results confirmed that seagrass loss results in carbon stock loss from the sediment. The study also produced the first emission factor for seagrass meadows, conveying what amount of stored carbon would be lost during habitat conversion. These numbers are extremely useful for resource managers when considering the impact of coastal development application. This project is the first of its kind in Thailand, and possibly one of only three in Southeast Asia, including the Philippines and Indonesia. It contributed to the ongoing process of enhancing the capacity of professionals and in developing appropriate climate change policy, financing, and management mechanisms in Thailand. It extended current scientific understanding of the role of seagrasses in climate change mitigation, and provided new Blue Carbon data for a region lacking significant data. Furthermore, this data informed the global community about carbon stocks in tropical regions, which is relatively underrepresented in the current global databases.

Building Blue Carbon Projects An Introductory Guide

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