Organic Carbon Storage in the sediment Upo Wetland revealed by using the 13C Fingerprinting Technique of Essential Amino Acids

The use of fossil fuels for global energy production has increased the concentration of CO₂ released into the atmosphere. Consequently, there has been an increase in the concentration of anthropogenic greenhouse gases in the atmosphere, which contributes to the increase in global average temperature. Therefore, carbon sinks and storage have been investigated to mitigate atmospheric CO₂ concentrations and reduce average temperature increases. This study aims to determine the potential of wetlands as a new carbon sink using stable isotope ratios. Four core samples were collected at Upo Wetland in June and August 2023. Radiocarbon, total organic carbon concentration, and stable carbon isotope of essential amino acids (δ¹³C_EAA) were analyzed from the sediment core samples. Cores No. 3, 4, and 5 indicate that sediment depths of approximately 0.2-0.4m were deposited over about 100 years, whereas core No. 2 showed the equivalent time to 1m sediment depth. Moreover, all four cores displayed organic carbon content exceeding 1% at deeper depths than 3m, indicating that Upo Wetland has the potential to store organic carbon for a long time. The each basal source contribution of organic carbon was determined using ¹³C fingerprinting of essential amino acids δ¹³C_EAA, with the freshwater phytoplankton, terrestrial plants, fungi, and bacteria serving as end-members. The sediments were found to be primarily composed of organic carbon from phytoplankton, accounting for over 90% of the total organic carbon source. Terrestrial plants contributed 0.7-5.3%, while bacteria and fungi contributed 0.4-2.3% and 0.6-3.8%, respectively. This indicates that the organic matter in the sediment of Upo Wetland is predominantly derived from phytoplankton. As a result, Upo Wetland seems to be a long term depository of organic carbon produced by the microalgal community.

Primary Presenter: Minhwa Gu, Hanyang university (alsmin317@gmail.com)

Authors:

Minhwa Gu, Department of Marine Sciences and Convergent Technology, Hanyang University  (alsmin317@gmail.com)

Sang Deuk Lee, Nakdonggang National Institute of Biological Resources  (diatom83@nnibr.re.kr)

Mirye Park, Nakdonggang National Institute of Biological Resources  (mirye@nnibr.re.kr)

Chae Hong Park, Department of Environmental Science water Environment & Ecology lab, Konkuk University  (qkrcoghd2@gmail.com)

Dae Ryul Kwon, Nakdonggang National Institute of Biological Resources  (kdyrevive@nnibr.re.kr)

Jihae Park, Department of Environmental Technology, Ghent University  (jihae.park@ghent.ac.kr)

Hoil Lee, Korea Institute of Geoscience and Mineral Resources  (hoillee@kigam.re.kr)

Kyung-Hoon Shin, Department of Marine Sciences and Convergent Technology, Hanyang University  (shinkh@hanyang.ac.kr)