Changes in the characteristics of organic matter associated with hydrodynamics and phytoplankton size structure in the central-eastern Yellow Sea

Yeonjung Lee; Dong Han Choi; Howon Lee; Myung Jin Hyun; Giyeong Kim; Haeun Lee; Wonseok Yang; Jihoon Kim; Jongseok Won; Kongtae Ra; Hyeryeong Jeong; Jin Young Choi; Seok Lee; Moonkoo Kim; Jae-Hoon Noh

doi:10.1016/j.scitotenv.2021.151781

Changes in the characteristics of organic matter associated with hydrodynamics and phytoplankton size structure in the central-eastern Yellow Sea

Sci Total Environ. 2022 Feb 10;807(Pt 3):151781. doi: 10.1016/j.scitotenv.2021.151781. Epub 2021 Nov 19.

Authors

Yeonjung Lee¹, Dong Han Choi², Howon Lee¹, Myung Jin Hyun³, Giyeong Kim², Haeun Lee¹, Wonseok Yang², Jihoon Kim², Jongseok Won², Kongtae Ra⁴, Hyeryeong Jeong⁴, Jin Young Choi⁵, Seok Lee⁶, Moonkoo Kim⁷, Jae-Hoon Noh⁸

Affiliations

¹ Marine Ecosystem Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea.
² 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.
³ Marine Ecosystem Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea; Department of Ocean Science, University of Science and Technology, Daejeon 34113, Republic of Korea.
⁴ Department of Ocean Science, University of Science and Technology, Daejeon 34113, Republic of Korea; Marine Environmental Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea.
⁵ Marine Environmental Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea.
⁶ Ocean Circulation and Climate Research Center, Korea Institute of Ocean Science and Technology, Busan 49111, Republic of Korea.
⁷ Department of Ocean Science, University of Science and Technology, Daejeon 34113, Republic of Korea; Risk Assessment Research Center, Korea Institute of Ocean Science and Technology, Geoje 53201, Republic of Korea.
⁸ 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. Electronic address: jhnoh@kiost.ac.kr.

PMID: 34801494
DOI: 10.1016/j.scitotenv.2021.151781

Abstract

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 (δ¹³C) and nitrogen (δ¹⁵N) 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 δ¹³C 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 δ¹³C 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 δ¹³C 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.

Keywords: Hydrodynamics; PARAFAC; Physical-biogeochemical interactions; Stable isotope ratio; Yellow Sea.

MeSH terms

Dissolved Organic Matter
Hydrodynamics*
Pacific Ocean
Phytoplankton*

Substances

Dissolved Organic Matter