Core Insights - The "Xiangzhou Cloud" scientific research vessel completed its first scientific expedition of 2026, focusing on the organic carbon cycle in the Pearl River Estuary [1] - The expedition involved collaboration among multiple institutions, including the Laoshan Laboratory, Ocean University of China, Sun Yat-sen University, and the Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) [1] Group 1 - The expedition took place from January 13 to January 17, 2026, and involved 13 researchers and students [1] - The research aimed to analyze the organic carbon cycle processes in the Pearl River Estuary and adjacent waters [1] - Key parameters such as temperature, salinity, and chlorophyll were measured using a Conductivity-Temperature-Depth (CTD) profiler [1][2] Group 2 - The team collected water samples for subsequent analysis of particulate organic carbon (POC) and dissolved organic carbon (DOC) [1] - Surface sediment samples were obtained using a box corer, and various instruments were employed to capture data on particle distribution and microbial imagery [1] - A significant amount of samples and continuous observation data were gathered, laying the foundation for understanding the organic carbon cycle mechanisms in the region [3]