UUV–USV 협력 미션을 위한 광–음향 하이브리드 수중 무선 통신시스템 개발

강진일 국립한국해양대학교 해양과학기술전문대학원 2025 국내박사

In recent years, cooperative operations between unmanned underwater vehicles (UUVs) and unmanned surface vehicles (USVs) have gained significant attention in various maritime applications such as ocean surveillance, underwater infrastructure inspection, and autonomous exploration. These missions require a reliable and real-time communication infrastructure that can autonomously adapt to the highly dynamic and three-dimensional marine environment. Conventional underwater acoustic communication offers long-range capability but suffers from low data rates and high latency. On the other hand, underwater wireless optical communication (UWOC) enables high-speed and low-latency transmission but is limited by short range and the need for precise optical beam alignment. To address these limitations, this paper proposes AquaLink, a hybrid underwater wireless communication system that integrates optical and acoustic communication technologies. Based on this system, a cooperative UUV–USV communication architecture is designed and implemented, and its performance is evaluated through both tank and open-sea experiments. AquaLink consists of five core hardware modules: (1) optical modem, (2) acoustic modem, (3) underwater environmental sensing system, (4) optical beam tracking and alignment system, and (5) integrated control system. The optical modem incorporates a high-power LD array transmitter and a SiPM-based high-sensitivity receiver, while the acoustic modem utilizes a BPSK modulation scheme for robust long-range communication. The system performs real-time optical beam alignment using relative position information derived from USBL and AHRS data, combined with received optical power measurements. Environmental sensing modules monitor turbidity, illumination, and depth to predict channel conditions and determine the feasibility of optical communication. An FSM-based adaptive communication control algorithm dynamically switches between optical and acoustic modes by evaluating real-time channel quality metrics such as SNR, PER, and received power. Moreover, an asymmetric communication protocol is implemented, allowing the UUV to uplink sensor and video data at high speeds, while the USV transmits control and command data with high reliability. The performance of the AquaLink system is validated in two experimental settings. In a controlled tank environment, quantitative measurements were conducted to evaluate BER, optical alignment accuracy, and communication throughput under varying turbidity and range conditions. In open-sea field tests, cooperative communication scenarios involving both stationary and mobile UUV–USV configurations were performed to assess link stability, mode switching delay, and directional robustness. The proposed system demonstrated superior performance over single-mode systems, achieving a 92% packet success rate, 1.6-second average mode switching latency, and over 93% alignment stability, even during mobile operations. This study successfully implements a practical underwater hybrid communication architecture capable of adapting to diverse and challenging marine conditions. The proposed AquaLink platform is expected to serve as a foundational technology for future applications in autonomous maritime collaboration, persistent underwater exploration, naval surveillance, and ocean resource monitoring. 최근 해양 감시, 수중 구조물 검사, 자율 해양 탐사 등 다양한 응용 분야에서 수중무인로봇(UUV)과 무인수상선(USV) 간의 협력 운용이 활발히 연구되고 있다. 이러한 협력 미션은 수중과 수상 간의 실시간, 고신뢰성 통신 인프라를 전제로 하며, 특히 동적 환경 변화에 능동적으로 적응할 수 있는 통신 시스템의 구현이 핵심 과제로 부상하고 있다. 기존 수중 통신 기술 중 하나인 음향통신은 장거리 전송이 가능하다는 장점을 갖지만, 낮은 전송 속도와 높은 지연(latency)으로 인해 실시간성 확보에 한계가 있으며, 광통신은 고속 데이터 전송과 저지연 특성이 장점이지만 전송 거리의 제한과 광축 정렬의 민감성으로 인해 활용에 제약이 있다. 본 논문에서는 이러한 한계를 극복하기 위해 광통신과 음향통신의 장점을 융합한 광–음향 하이브리드 수중 무선통신 시스템인 AquaLink를 제안하고, 이를 기반으로 한 UUV–USV 협력 통신체계를 설계 및 구현하였으며, 수조 및 실해역에서의 성능 검증을 통해 그 실효성을 입증하였다. AquaLink는 광통신 모뎀, 음향통신 모뎀, 수중 환경 센서시스템, 광축 추적 및 정렬 시스템, 통합 제어시스템 등 5개의 핵심 하드웨어 모듈로 구성되며, 고출력 LD 송신기 및 SiPM 수신기를 활용한 광통신 시스템과, BPSK 기반 장거리 음향통신 모뎀을 하나의 플랫폼에 통합하였다. 본 시스템은 USBL 및 AHRS 기반의 상대 위치정보와 수신 광파워 정보를 융합하여 2축 또는 3축 광축 정렬을 실시간으로 수행하며, 탁도·조도·수심 측정값을 기반으로 링크 상태를 예측하고, 통신 가능성을 판단하여 광–음향 간 통신모드를 자율적으로 전환한다. 이를 위해 개발된 통신모드 전환 알고리즘은 FSM(Finite State Machine) 기반의 구조로 설계되었으며, 실시간 채널 품질(SNR, PER, 수신파워 등)을 종합적으로 평가하여 링크 유지 및 전환 여부를 결정한다. 또한, 플랫폼 간 비대칭 통신 특성을 반영하여 UUV는 영상 및 센서 데이터를 고속 업링크하고, USV는 명령 및 제어 신호를 저속이지만 안정적으로 전송할 수 있도록 비동기 구조를 구현하였다. AquaLink 시스템의 성능 검증은 실내 수조 환경에서의 정량 평가와 실해역 실험을 통해 이루어졌다. 수조 실험에서는 다양한 거리 및 탁도 조건에서 광통신 링크의 BER, 수신파워, 정렬 정밀도를 측정하였고, 해상 실험에서는 정박 및 이동 상태에서의 하이브리드 통신 운용 시나리오를 적용하여 통신 거리, 모드 전환 시간, 링크 유지율 등의 항목을 평가하였다. 실험 결과, 광–음향 하이브리드 시스템은 기존의 단일 모드 대비 높은 링크 안정성(92%), 짧은 전환 지연 시간(1.6초), 광축 정렬 유지율(93.5%)을 달성하였으며, 특히 이동 중에도 안정적인 광통신 링크 유지가 가능함을 확인하였다. 결론적으로, 본 연구는 수중 환경의 가변성과 제한 조건을 고려한 실시간 적응형 통신 시스템을 실용적 수준에서 구현하였다는 데에 의의가 있으며, 향후 해양 자율 협력 시스템, 장기 수중 탐사, 해양 국방 감시 체계 등 다양한 응용 분야에서의 기반 기술로 활용될 수 있을 것으로 기대된다.

고수온 프록시의 이용 적절성 평가 : TEX86과 유공충의 산소안정동위원소비

고태욱 국립한국해양대학교 해양과학기술전문대학원 2025 국내박사

TetraEther indeX of tetraethers with 86 carbon atoms (TEX86) and the stable oxygen isotope ratios of planktonic foraminifera (δ18Opforam) are widely used paleo-temperature proxies for reconstructing past sea surface temperatures. However, these proxies are influenced by various ecological and physical factors, including the habitat depth, seasonality, vertical migration behavior of the source organisms, and the resuspension of sediments. Such factors introduce uncertainty regarding the depth and seasonality of the water temperatures recorded by these proxies. In this study, seawater samples were collected under varying seasonal, vertical, and diurnal conditions, and the temperature signals of each proxy were assessed based on the analysis of isoprenoid glycerol dialkyl glycerol tetraethers (i-GDGTs) for TEX86 and δ 18Opforam. To evaluate the applicability of TEX86 as a seawater temperature proxy, suspended particulate material (SPM) samples were collected from the northern East China Sea at three-month intervals within the upper 100 m of the water column. The distributions of i-GDGTs in surface and subsurface water samples were analyzed to calculate TEX86 values. TEX86 values were compared with measured in situ temperatures. In the western part of the study area, where the water depth was shallower than 100 m, i-GDGT concentrations were elevated near the seafloor. The calculated TEX86 temperatures deviated from the measured temperatures. These results support the possibility of sediment resuspension. In contrast, in the deeper eastern area, i-GDGT concentrations peaked at the depth of 20–50 m. The TEX86-derived temperatures closely matched the in situ temperatures. These findings indicate that TEX86 reflects the temperature of the main GDGT production depth (20–50 m) rather than the sea surface. This highlights the need to consider region-specific vertical GDGT distribution patterns when interpreting TEX86-based reconstructions. To evaluate the limitations of δ18Opforam as a temperature proxy, seawater samples were collected in the tropical western Pacific. Samples were collected at various depths (0–600 m), during spring, summer and winter, at day and night. δ18Opforam was measured in multiple planktonic foraminiferal species. Calcification depths were estimated by comparing δ18Opforam values with in situ temperature and seawater δ18O. These depths were also compared with habitat depths estimated from species-specific abundance data reported in previous studies. Calcification depths based on δ18Opforam were generally consistent with habitat depths estimated from foraminiferal abundance. The results show that δ18Opforam values responded sensitively to depth-related and seasonal changes in the thermocline. This suggests that δ18Opforam can be used not only to calculate SST but also to reconstruct vertical temperature structure. This study quantitatively compared the depth sensitivity, seasonality, and environmental responses of the TEX86 and foraminiferal δ18O proxies. It highlights the importance of prior evaluation of regional and biological factors when applying these proxies for seawater temperature reconstruction. The findings are expected to provide a basis for future proxy-based reconstruction strategies of past sea temperatures and vertical temperature structures. Key words: Paleo-temperature proxy, TEX₈₆, foraminiferal δ18O, production depth, habitat depth, seasonality

산업부산물 기반 Vaterite형 CaCO3 생산을 위한 간접탄산화 공정의 경제성 향상에 관한 연구

조원 국립한국해양대학교 해양과학기술전문대학원 2025 국내석사

This study aims to enhance the economic feasibility of indirect carbonation processes by utilizing industrial by-products to produce high-purity vaterite-type CaCO3) In the first part, a seawater desalination brine was used as a solvent, and Ca(OH)2, a cost-effective alternative to conventional alkali agents such as NaOH, was employed. To improve the solubility of Ca(OH)2, sucrose was added, resulting in significantly increased CaCO3 yield and purity (96–98%) while reducing production costs by up to 53%. In the second part, flue gas desulfurization gypsum was subjected to indirect carbonation under ambient temperature and pressure conditions. By applying a low-concentration ammonium acetate solution with additives such as NaOH, sucrose, and NaF, high-yield, fine-particle vaterite-type CaCO3 was successfully synthesized. Compared to conventional high-temperature and high-pressure processes, the proposed method significantly reduced chemical usage and energy demand. Collectively, both studies demonstrate the potential of industrial waste valorization and process optimization for sustainable and economically viable carbon capture, utilization, and storage (CCUS) technologies. Keywords : CCUS, indirect carbonation, pH-swing, vaterite, Industrial by-products, Resource recycling

복사 전달 모델 기반 하향 확산 감쇠 계수의 불확도 분석에 관한 연구=

이한빛 국립한국해양대학교 해양과학기술전문대학원 2025 국내석사

The diffuse attenuation coefficient for downwelling irradiance (Kd) is an apparent optical property (AOP) that describes the exponential decrease of light with depth due to scattering and absorption by constituents in the seawater. It is one of the key products used to study of ocean turbidity, primary production, and other bio-optical processes. For large-scale oceanic applications, Kd is commonly retrieved using remote-sensing reflectance (Rrs) derived from ocean color satellite. Recently, semi-analytical models based on radiative transfer theory have been developed to estimate Kd from inherent optical properties (IOPs), and are widely applied. However, such models may not fully account for varying environmental conditions, leading to estimation errors than depend on specific variables. In this study, we employed HydroLight simulations to evaluate the impact of four major environmental variables—solar zenith angle (SZA), wind speed, aerosol type, and aerosol optical depth (AOD)—by setting their minimum and maximum values across three water types (clear, intermediate, and turbid conditions). The impact of each variable was analyzed by comparing the Kd derived from a semi-analytical model using IOPs obtained from the simulation. The results showed that SZA had the most significant impact across all water types, with the percentage error varying from 10.21% in clear waters to 28.17% in turbid waters. While AOD had a relatively smaller effect, its influence increased with turbidity, reaching up to 17.93%. In contrast, wind speed and aerosol type showed minimal impact, with maximum error differences of 2.75% and 0.05%, respectively. In particular, significant errors occurred due to SZA, despite it being already accounted for in the semi-analytical Kd model, suggests a limitation of the Kd model and indicates the need to consider turbidity as an additional factor. To improve the accuracy of Kd estimates, the development of additional correction algorithms that better correct for the influences of SZA and turbidity is necessary. This study provides a quantitative assessment of Kd errors under various environmental conditions based on radiative transfer model and serves as a foundational reference for developing more accurate Kd algorithms applicable to diverse marine environments. Keywords : Diffuse Attenuation Coefficient for Downwelling Irradiance, Radiative Transfer Model, HydroLight Simulation, Uncertainty Analysis

Ra 동위원소를 활용한 연안 해수에서의 페놀 거동 연구

유해인 국립한국해양대학교 해양과학기술전문대학원 2025 국내석사

We investigated the concentrations of total phenol in seawater (11) and river water (1) collected in Sacheon area, where a thermal power plant is located, in South Korea. The concentration of phenol was analyzed using gas chromatography-mass spectrometry (GC-MS), ranging from 0.3 to 1.3 (0.6±0.3) µg/L. These values were significantly lower than the permissible discharge standards of water pollutants for phenol in water(< 1,000 µg/L). As phenol exists in seawater as dissolved state, the accuracy of the analysis was improved by using dissolved substances instead of traditional methods for analyzing particular substance behavior. Radium (Ra) isotopes, present in seawater in a form similar to phenol, were used to estimate the residence time. The concentration of the naturally occurring radioactive Ra-223 and Ra-224 were analyzed using a radium delayed coincidence counter (RaDeCC). The residence time of seawater in the Sacheon coastal area, calculated using the Ra-224 and Ra-223 activity ratio model, was ~2.7 (1.3±1.0) days. The results provide important data for predicting the rate of phenol and other dissolved substances in coastal spill incidents and assist in developing appropriate response strategies. Keywords Phenol, Ra isotopes, Residence time, Sacheon, Industrial facilities 본 연구에서는 화력발전소가 위치한 사천 연안에서 해수 (11개 정점)와 하천(1개 정점)의 페놀(phenol)의 농도를 측정하여 그 거동에 관한 연구를 수행하였다. 사천 해역 내 페놀 거동을 분석하기 위해 기체크로마토그래피-질량분석기(GC-MS)를 활용하여 해수 중 페놀의 농도를 분석하였다. 사천 연안의 해수 중 페놀 농도는 0.3–1.3 (0.6±0.3) µg/L으로 국내 페놀의 수질 오염 배출 허용기준(<1,000 µg/L)보다 현저히 낮았다. 농도 분포를 분석한 결과, 사천 해역 내 페놀 농도는 평균적으로 낮은 농도이지만, 일부 정점에서는 상대적으로 높은 농도가 확인되었다. 하천 주변에 농지와 같은 비점오염원이 위치하여 페놀 배출 관리가 상대적으로 어려워 해수 중 페놀의 농도(0.3–0.8 µg/L)보다 하천에서의 페놀 농도(0.9 µg/L)가 더 높게 나타났다. 또한 일부 정점에서는 해수의 저층에서 페놀 농도를 확인한 결과, 수심이 깊어질수록 페놀 농도가 증가하는 경향을 보여, 페놀이 침강하는 형태로 존재함을 확인할 수 있었다. 해수 중 페놀은 주로 용존 상태로 존재하므로, 기존의 입자상 물질을 기반으로 한 분석 방법보다 용존 물질을 활용하는 방식이 정확도를 높일 수 있을 것으로 판단된다. 이를 위해 해수에서 페놀과 유사한 형태로 존재하는 Radium (Ra)의 동위원소를 활용하여 체류시간을 산정하였다. radium delayed coincidence counter (RaDeCC)를 사용하여 자연 방사성물질인 Ra 동위원소 중 Ra-223와 Ra-224의 농도를 측정하고, 이들의 농도비를 이용하여 연구 지역 내 물의 체류시간을 계산하였다. Ra-224와 Ra-223의 농도비를 이용하여 산정된 체류시간은 평균 1.3±1.0일이었다. 이 결과를 통해 페놀 및 다른 용존 화학물질의 연안 유출 사고 발생 시, 해수 중 해당 물질의 체류시간을 산정하여 물질의 거동을 예측하고 적절한 대응 방안을 수립하기 위한 유용한 기초 자료로 활용될 수 있을 것으로 판단된다.

Benthic respiration and heavy metal benthic fluxes in artificial Shihwa Lake : Approaching in situ measurement

조유현 국립한국해양대학교 해양과학기술전문대학원 2024 국내석사

Since the 1990s, heavy metals, organic compounds, and nutrients from the industrial complexes have contributed to the deterioration of Shihwa Lake’s ecosystem. However, benthic processes that significantly control water quality have received less attention. This study assessed the impact of intensive human activities on organic matter (OM) and heavy metal cycles in Shihwa Lake, South Korea. Sediment oxygen demand (SOD), benthic nutrient flux (BNF), and benthic heavy metal flux were estimated using in situ benthic chambers. The combined analysis of sediment trap and SOD showed that vertical supply of OM was a major controlling factor for benthic respiration, The BNF accounted for 35–144% and 32–184% of the N and P requirements, respectively, for primary production (PP) in the water column. The higher SOD may have also accelerated the release of Mn, Fe, Co, and Ni from the sediment. Benthic fluxes of Cr, As, Cd, Pb, Cu, and Zn were the highest near the industrial complex, with ranges of 1.3 ± 0.9, 6.4 ± 4.9, 0.2 ± 0.1, 0.5 ± 0.4, 7.7 ± 1.4, and 452 ± 133 mmol m–2 d–1, respectively. Mn, Fe, Co, As, Pb, Ni, and Cu contributed more than 10 % of the sediment to the current standing stock at Shihwa Lake. 본 연구에서는 시화호 내의 퇴적물에서 유기물 분해 특성, 퇴적물로부터의 영양염과 중금속 용출 및 주요 조절요인을 파악하기 위해 유기탄소산화율 및 영양염과 중금속 용출율을 측정하였다. 연구정점은 시화호 내측 산업단지 인근 정점 (SH1, SH2), 중간지점 (SH3), 농업단지 인근 정점 (SH4), 시화호 외측 (SH5)으로 선정하였다. 퇴적물-수층 경계면에서의 산소소모율, 영양염 및 중금속 용출율은 현장관측장비를 통해 측정하였다. 시화호 내에서 유기탄소산화율은 침강입자 플럭스가 가장 큰 정점에서 가장 높았으며 (R2=0.99), 이는 유기물의 수직적 공급이 저층 호흡률을 결정하는 주요 요인인 것으로 생각된다. 시화호 내에서 퇴적물로부터 용출된 무기질소와 무기인은 각각 일차생산자가 요구하는 무기질소와 무기인의 35–144%와 32–184%를 공급하는 것으로 나타났다. 산업단지 인근 정점 SH1, SH2에서 Cr, As, Cd, Pb, Cu, Zn의 퇴적물로부터 용출율이 가장 높았으며, 각각 1.3 ± 0.9, 6.4 ± 4.9, 0.2 ± 0.1, 0.5 ± 0.4, 7.7 ± 1.4, and 452 ± 133 mmol m–2 d–1 였다. 반대로 정점 SH4에서 퇴적물로부터 용출된 Mn, Fe, Co, Ni가 가장 높았으며, 이는 유기탄소산화율과 상관성이 매우 높은 것으로 나타났다. 퇴적물로부터 Mn, Fe, Co, As, Pb, Ni, Cu의 용출농도는 시화호 내에서 존재하는 수층 중금속 농도에 10% 이상을 기여하고 있었다.

Impact of seasonal hypoxia on sediment geochemistry, organic carbon budget, and benthic nutrient flux in a semi-enclosed bay

정현정 국립한국해양대학교 해양과학기술전문대학원 2025 국내석사

Benthic dissolved inorganic carbon, total alkalinity, and nutrient fluxes were measured at stations H (hypoxia) and C (control) using an in situ benthic chamber in April, June, September, and December 2023 to assess the effect of seasonal hypoxia on sediment biogeochemistry in Jinhae Bay (JB). The concentrations of dissolved oxygen in the bottom water and sediment geochemistry are influenced by a combination of stratification and rates of organic carbon (OC) oxidation, which leads to a significant accumulation of reduced compounds (NH4 +, PO4 3−, and HS−) in June and September. The rates of organic carbon oxidation (OCox) in the sediment showed a positive correlation with the concentration of chlorophyll-a in the surface sediment, indicating that labile organic material stimulates OCox. The suspended particle materials by resuspension and/or rainfall precipitation are a key factor in regulating a series of OC cycles and sustaining hypoxic conditions in the bottom water. The combination of low oxygen concentration in the bottom water and higher OCox at station H promotes the release of benthic nutrients, which regulates nutrient dynamics and ecosystems in JB.

Antarctic marine actinomycetes from the Amundsen sea : An unexplored source of secondary metabolites for marine natural products

강수진 국립한국해양대학교 해양과학기술전문대학원 2025 국내석사

This study explores the diversity of actinomycetes isolated from the Amundsen Sea in Antarctica and investigates their potential to produce secondary metabolites. Actinomycetes have long been recognized as a major microbial source of diverse secondary metabolites in natural product research. The Antarctic marine environment, with its extreme conditions and limited exploration, offers a promising opportunity for discovering novel bioactive compounds. Marine sediment samples were collected from 17 different sites in the Amundsen Sea by the icebreaking research vessel ARAON. From these samples, a total of 25 actinomycetes were isolated in the laboratory. These isolates belonged to eight different genera, indicating a high level of phylogenetic diversity. Crude extracts of the isolated strains were evaluated for antibacterial activity and cytotoxicity, and several strains exhibited bioactivity. Among them, strain LMA743 showed weak activity in the initial screening. However, it demonstrated strong antibacterial and cytotoxic effects in the fractionated extracts obtained through large-scale fermentation. This study highlights the potential of Antarctic marine actinomycetes as a valuable source of bioactive secondary metabolites. In addition, it emphasizes the importance of further natural product research on Antarctic marine-derived actinomycetes.

A study on the diversity of marine benthic diatoms in the sand flats of Northeast Asia

Kim, Hyesuk 국립한국해양대학교 해양과학기술전문대학원 2025 국내박사

Diatom communities were investigated in seven sand flats in Northeast Asia (Korea, China, and Japan). Surface sediments were collected from three sites in Korea (Goraebul, Sinduri, and Myeongji sand flats), two sites in Bohai Bay in China (Qinhuangdao and Weifang sand flats), and two sites in Japan (Hakata and Arao sand flats). To observe diatom shells, the collected sediment samples were treated with hydrochloric acid and hydrogen peroxide to remove calcium carbonate and organic matter. For optical microscopy, a permanent preparation was made with resin, and 300 diatom valve per site were observed using an Olympus BX53 light microscope equipped with a Zeiss Axiocam 208 color camera. A Tescan Clara electron microscope was used for precise identification of the observed diatoms. Adobe Photoshop 2020 program was used for the illustration work. A total of 257 species belonging to 49 genera were observed at seven stations in the Northeast Asian sand flats. Dominant genera included Navicula, Amphora, and Planothidium. On the other hand, dominant species included Catenula adherens, Navicula spartinetensis, Navicula sp. 23, Catenula sp. 1, Nitzschia sigma, and Halamphora cf. wisei. Based on the distribution of diatoms and the grain size of sediments, the seven stations were divided into two groups. First, the sand flats of Goraebul, Shinduri, Hakata, and Arao, which had sand contents of more than 90%, were grouped together. Catenula adhesa, which is well known to inhabit sandy environments, was dominant at these stations. On the other hand, the sand flats of Mingchi, Qinhuangdao, and Weifang were grouped together as sand flats mixed with mud with sand contents of less than 80%. Navicula spartinetensis was dominant in these areas with relatively high mud contents. Navicula spartinetensis is well known as a species that prefers muddy environments. New species were observed in the sand flats of Northeast Asia. One new genus (Moregramma) and seven new species (one species of Moreneis, one species of Petroneis, one species of Cavinula, one species of Cocconeiopsis, and three species of Navicula) were identified in this study. Keywords: Marine Benthic Diatoms, Northeast Asia, sandy tidal flats, diatom communities, diatom distribution, phenology, new species

Sedimentary organic carbon and nutrient cycles in the continental shelf of the southern Yellow Sea

Baek, Ju-Wook 국립한국해양대학교 해양과학기술전문대학원 2025 국내박사

The continental shelf is important component for global carbon cycle. Because the significant influxes of organic matter driven by its high primary productivity and inputs from adjacent land, high organic matter decomposition and burial are occurred in continental shelf sediment. Also, nutrients are remineralized during the decomposition of organic matter and released from the sediments along gradient between sediment and water column. The release of nutrient from sediment potentially serving as a nutrient source for primary producers. The examining of behavior of organic matter in continental shelf sediment is essential for understanding the marine organic carbon cycle. The Yellow Sea is a semi-enclosed shelf sea in the western Pacific, surrounded by the Korea and the China. The Yellow Sea characterized by high input of organic matter due to two organic matter sources such as high primary production and rivers and deltas and its relatively shallow depth allowing settling of organic matter into the benthic layers. The interaction between hydrodynamics (currents, tides, and wave) with organic matter sources, resulting in a complex grain size and organic carbon composition and contents in the Yellow Sea. The development of the Yellow Sea Cold Water Mass in the benthic layer of Yellow Sea has increase the fine-grain sediment and organic carbon content, which occurred the spaital variation of sediment organic carbon dynamic. As a result, spatial and temporal variation sediment organic carbon flux was controlled by physical and chemical interactions. Meanwhile, benthic nutrient fluxes affected by the variation of sediment organic matter remineralization in the Yellow Sea shelf. However, studies on benthic organic carbon and nutrient fluxes on the Yellow Sea continental shelf have been limited to specific areas. The aims of this study to investigate the sedimentary organic carbon and nutrient cycles on the Yellow Sea continental shelf through the following approaches:(1) estimating the characteristics of organic matter decomposition and decomposition pathways, as well as benthic nutrient release fluxes, between Yellow Sea cold water mass (CWM) and non-Yellow Sea cold water mass on the Yellow Sea continental shelf, (2) assessing the sediment organic carbon budget and evaluating benthic-pelagic coupling based on the spatiotemporal variability of sediment organic carbon and benthic nutrient fluxes on the Yellow Sea continental shelf, (3) identifying the spatial variability of sediment oxygen consumption rate and benthic nutrient flux in across the southern Yellow Sea, including South Korean territorial waters, during the spring. (1) Sediment organic carbon oxidation and benthic nutrient flux in the continental shelf of the southern Yellow Sea We investigated the total sediment O2 uptake, sulfate reduction rate, and benthic nutrient flux at the Yellow Sea cold water mass sediments (N3509 and N3507) and the coastal sediment (N3503) in the southern Yellow Sea. The organic carbon content increased from coarse- to fine-grained sediment, which was by far the highest at N3503 (0.89% and 6.1 Ø), followed by N3509 (0.72% and 4.5 Ø) and N3507 (0.15% and 3.0 Ø). The bottom water temperature at N3503 (16.0°C) was 6-7°C higher than N3509 (10.2°C) and N3507 (9.0 °C). The total sediment O2 uptake and sulfate reduction rate at N3503 were 24.5 ± 5.0 mmol O2 m–2 d–1 and 6.5 mmol S m–2 d–1, 3 - 6 times higher than the values measured at N3509 and N3507 (5.5 ± 0.2 and 4.2 ± 0.3 O2 mmol m–2 d–1 and 0.9 and 0.7 mmol S m–2 d–1, respectively). The total sediment O2 uptake showed a positively correlated with both the organic carbon content and the bottom water temperature (R= 0.71, p &lt; 0.001). The behthic nutrient flux at N3503 (3.4 mmol N m–2 d–1, 0.5 mmol P m–2 d–1, 3.8 mmol Si m–2 d–1) was 3-37 times higher than the values measured at N3509. The behthic nutrient flux account for 72-179% of the nutrients required for primary production at N3503, whereas the contribution of behthic nutrient flux was less than 30% at N3509. (2) The sedimentary organic carbon budget and benthic-pelagic coupling in the continental shelf sediments of the southern Yellow Sea. We investigated sediment organic carbon (OC) flux and benthic nutrient flux (BNF) to estimate the sedimentary OC budget and benthic-pelagic coupling in the continental shelf of the southern Yellow Sea. During the spring to autumn seasons, sediment oxygen flux, BNF, sediment grain size, OC content, and sedimentation rates were analyzed in the Yellow Sea Cold Water Mass (YSCWM; N3513 and N3509) sediment and non-Yellow Sea Cold WaterMass (N-YSCWM; N3503) sediment. Sediment OC burial flux ranged from 0.4 to 2.8 mmol C m–2 d–1, and the highest values were found at N3513 with fine-grained and high OC content and sedimentation rates. The TOU measured by in situ experiments ranged from 5.83 ± 0.03 to 24.5 ± 4.99 mmol O2 mmol m–2 d–1. Except for spring, TOU in the N-YSCWM sediment was approximately 2–5 times higher than in the YSCWM sediment in summer and autumn. Sediment OC oxidation flux was significantly correlated with temperature variations (r = 0.83, p &lt; 0.01). The sediment OC oxidation efficiency (76–95%) was relatively higher than the OC burial efficiency (4–24%), which indicates that almost all the OC introduced to sediment was remineralized. The BNF in the N-YSCWM sediment ranged from 0.4 ± 0.04 to 3.17 ± 0.95 mmol N m–2 d–1 and from 0.04 ± 0.01 to 1.80 ± 0.09 mmol P m–2 d–1, which is 8–30 times higher than those measured at YSCWM sediments. As a result, BNF in the N-YSCWM sediment contributed 2–179% of the nutrients required for PP, while those in the YSCWM sediments accounted for less than 30% 3) Spatial variability of sediment oxygen consumption and benthic nutrient fluxes in the continental shelf of the southern Yellow Sea during Spring To understand the factors controlling organic carbon (OC) cycling in continental shelf sediment, we estimated total sediment oxygen uptakes (TOU) and benthic nutrient fluxes (BNF) in the southern Yellow Sea (SYS) during spring. The TOU ranged from 11.9 ± 0.02 to 20.5 ± 0.03 mmol O2 m-2 d-1, depending on the spatial distribution of OC content, with higher values in finer sediments. Sediment OC oxidation rates varied between 9.14 and 15.8 mmol C m-2 d-1, accounting for 5–87 % of primary production in surface waters. The BNFs were comparable with other continental shelves, with dissolved inorganic nitrogen and dissolved inorganic phosphate fluxes contributing 1 to 33% and 2 to 14%, respectively, of the nutrients required for primary production. The findings suggest that sediment OC quantity and quality, influenced by sediment type, are major factors controlling the spatial distribution of benthic OC cycles in the SYS. However, the benthic–pelagic coupling in the SYS during spring was weak, primarily because of low sediment OC oxidation and BNF rates. This study highlights the need for further research on temporal variability to fully understand the biogeochemical cycles in the Yellow Sea Keywords: Total sediment oxygen uptake, Benthic nutrient flux, Organic carbon, sediment type, Continental shelf, Yellow Sea