Marine Ecosystem Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea.
Marine Ecosystem Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea; Department of Convergence Study on the Ocean Science and Technology, Ocean Science and Technology School, Korea Maritime and Ocean University, Busan 49112, Republic of Korea.
Sci Total Environ. 2022 Feb 10;807(Pt 3):151781. doi: 10.1016/j.scitotenv.2021.151781. Epub 2021 Nov 19.
The central-eastern Yellow Sea is an important region for transporting organic matter (OM) to the Pacific Ocean, however, there is limited information available regarding the characteristics and sources of OM in this area. The present study investigated the concentrations and stable isotopic compositions of carbon (δC) and nitrogen (δN) for particulate matter and sediment in the central-eastern Yellow Sea during April 2019. The physicochemical properties (i.e., salinity, temperature, fluorescence, and nutrients), size-fractionated phytoplankton biomass (Chl-a), and concentration and fluorescence characteristics of dissolved organic matter (DOM) were also determined. The satellite SST and Chl-a data indicated that mixing cold and warm water masses were observed. Phytoplankton blooms occurred a few days before our sampling campaign. Considering the high concentration of suspended solids in the bottom layer, resuspended sediment caused by tidal currents could be a major source of OM in coastal areas. The δC values of particulate organic matter (POM) in the coastal area were higher (-23 to -22‰) than those of OM from terrestrial sources (approximately -28 to -27‰). Instead, the lowest δC values were observed in the central part of our study area, where the relative abundance of picophytoplankton was high. These results indicated that phytoplankton-derived OM after phytoplankton spring blooms in the coastal area could be the primary source of OM rather than terrestrial origins. In addition, the source of OM that presented low δC values could be picophytoplankton-derived OM. The characteristics of DOM were related to biological processes (mediated by phytoplankton and bacteria) and resuspension of sedimentary organic matter. We did not detect an influx of large amounts of terrestrial OM in coastal sediments. Overall, the source and characteristics of OM appeared to be influenced by the hydrodynamics and the distribution properties of lower trophic-level organisms in the central-eastern Yellow Sea during the spring season.
黄海中部和东部是向太平洋输送有机物质（OM）的重要区域，但该区域 OM 的特征和来源的信息有限。本研究调查了 2019 年 4 月黄海中部和东部的颗粒物和沉积物中碳（δC）和氮（δN）的浓度和稳定同位素组成。还测定了理化性质（即盐度、温度、荧光和营养物质）、大小分级的浮游植物生物量（Chl-a）以及溶解有机物质（DOM）的浓度和荧光特征。卫星 SST 和 Chl-a 数据表明，观测到冷暖和温水混合。浮游植物大量繁殖发生在我们采样之前的几天。考虑到底层悬浮固体的浓度较高，潮流引起的再悬浮沉积物可能是沿海地区 OM 的主要来源。沿海地区颗粒有机物质（POM）的 δC 值较高（-23 至-22‰），而陆地来源的 OM 约为-28 至-27‰。相反，在我们研究区域中部观察到最低的 δC 值，那里的微微型浮游植物相对丰度较高。这些结果表明，沿海地区浮游植物春夏季大量繁殖后产生的浮游植物衍生 OM 可能是 OM 的主要来源，而不是陆地起源。此外，具有低 δC 值的 OM 的来源可能是微微型浮游植物衍生的 OM。DOM 的特征与生物过程（由浮游植物和细菌介导）和沉积物中有机物质的再悬浮有关。我们没有在沿海沉积物中检测到大量陆地 OM 的涌入。总体而言，春季黄海中部和东部的水动力和低营养级生物的分布特性似乎影响了 OM 的来源和特征。
