72 / 2024-09-05 15:18:31
Behaviors of dissolved trace elements associated with humic dissolved organic matters of different origins in coastal seawater
Humic substances,Scavenging,Trace elements,Coastal ocean
Session 10 - The biogeochemistry of trace metals in a changing ocean
Abstract Accepted
Xiaoyu Chen / Seoul National University;Korea Institute of Ocean Science and Technology
Hyeong Kyu Kwon / Seoul National University
Guebuem Kim / Seoul National University
Intae Kim / Korea Institute of Ocean Science and Technology
The biogeochemical cycling of bio-essential trace elements in coastal seawater regulates their fluxes to the open ocean hence influencing the marine primary production. In this study, the behaviors of dissolved trace elements, Rare Earth Elements (REEs), and humic dissolved organic matters (DOMH) of terrestrial versus marine origins were investigated in the surface waters of two coastal regions in Korea. Despite the occurrence of intensive scavenging processes revealed by the REE behaviors and rapid removal of particle-reactive 234Th as well as significant biological removal processes, our results showed that both terrestrial and marine origins of DOMH would associate with dissolved trace elements, especially with Mn, Fe, and Cu, which would protect these elements from being removed by particle scavenging or biological uptake. This association process could result in a longer residence time for these trace elements in the water columns, hence travelling longer distances. Moreover, this study discovers that the stabilization of trace elements by different sources of DOMH could be variable depending on the biogeochemical processes. Thus, the association of trace elements with DOMH seems to play a key role in the shuttling of bio-essential trace elements to the open ocean via coastal oceans.