Evaluation of Carbon Sequestration in Seagrass Meadows of Kenting: A Comparative Study With Penghu and Dongsha Island

Abstract

This study investigates the controlling factors of carbon sequestration (CS) in seagrass bed sediments across three distinct environments in Taiwan: the Kenting (KT) coastal area, the Penghu (PH) open inner bay, and the Dongsha (DS) Atoll lagoon. Actual measurements of the substrate depth beneath the sediment and ground-penetrating radar (GPR) scans of the beach reveal that the coral reef bedrock in KT slopes landward. A field survey of the seagrass area in KT was conducted, and three cross-sectional profiles were analyzed to determine their topography, yielding a median sediment thickness of 88.2 cm. Based on these measurements, the sediment volume was estimated at 5.16pound 1010 cm3. By analyzing the total organic carbon (TOC) content of seagrass sediments, this study provides insights into how regional environmental conditions influence carbon storage in Taiwan's seagrass meadows. Our results reveal significant regional variability, with sediment carbon storage reaching 49.0 MgC/ha in KT, over 13.2 MgC/ha in PH, and an exceptional 145.7 MgC/ha in the extensive seagrass meadows of DS. These findings underscore the critical role of environmental stability in enhancing carbon sequestration. In particular, the Dongsha Islands exemplify how regions with low wave energy offer favorable conditions for maintaining high carbon storage. Additionally, our analysis suggests that carbon from aquatic plant sources may have potential contributions in the KT area. Finally, this study also compares the global and regional contributions of seagrass beds to carbon storage, including examples from the Mediterranean region, Japan, Taiwan, and Thailand. Preliminary findings indicate that the carbon sink capacity of seagrass meadows in Asia is significantly lower. This observation warrants further investigation and continued research.