제목: Microbially Mediated Biogeochemical Processes in Coastal Sediments under Varying Water Column Hypoxia: Interactions among C-Fe(Mn)-S-P​​​​​​​​​​​

​​

​​​​​​​​​​​​​​​​​​연사: 현정호 교수 (한양대학교)​​​​​​

​

장소: 과학관 B101호​​

Abstract:

Ocean deoxygenation is a growing ecological and oceanographic concern globally. In coastal ecosystems, water column hypoxia (WCH), defined as a dissolved oxygen (DO) concentration < 63 µM or 2 mg L-1, is primarily caused by a combination of physically stagnant water conditions and enhanced nutrient inputs from land-based fertilizers and wastewater.

This seminar presents how changing WCH alters biogeochemical element cycles in coastal sediments. Firstly, we conducted fine-scale investigation on the partitioning of major organic carbon (Corg) mineralization processes, the reduction of manganese (MnR), iron (FeR) and sulfate (SR), and resulting Mn-Fe-S-P dynamics at two geochemically contrasting coastal sites with different manganese content. Secondly, to further clarify WCH effects on the Mn distributions and benthic flux, and precipitation of Mn minerals in coastal sediments enriched with Mn, we combined sediment incubation experiments with X-ray absorption near edge structure (XANES) analysis.

Overall results provide crucial information to elucidate cause-effect relationships behind observed phenomena on the distributions and flux of elements in coastal environments where WCH is expanding due to climate change and excessive human activities.​