Organic carbon stocks of the surficial sediments in the territorial waters of Korea

Abstract

Shallow marine environments, including the continental shelf, are important in the global carbon cycle in which organic carbon is transported from land, produced within the ocean, and buried in sediments. The territorial waters of Korea (Republic of Korea) encompass predominantly shallow continental shelves. This study examined the organic carbon distribution of surficial sediments in the territorial waters of Korea to approximate the carbon stocks in the surficial sediments of the seafloor at a national scale. For the estimation, the reported data (mean grain size (MGS), total organic carbon (TOC) content, and dry bulk density) around the Korean Peninsula were documented and organized to evaluate the potential for carbon sequestration in the territorial waters of Korea. The distribution of the MGS and the TOC content in surficial sediments varied regionally according to the depositional processes, but they exhibited the typical characteristics of marine sediments whose TOC content increased as the MGS decreased. Among the four zones (A, B, C, and D) in the territorial waters of Korea, the estimated total carbon stock was highest (2.27×10^6 Mg C) in zone A and lowest (1.04×10^6 Mg C) in zone C, despite zone C having the highest carbon stock per unit area (1.64 Mg C/ha). However, for a precise assessment of long-term carbon stock and sequestration rates, more comprehensive and robust data along with representative sedimentation rates and the vertical profiles of the TOC content are essential at a national scale.