98%
921
2 minutes
20
We investigated the source, composition, and reactivity of particulate organic carbon (POC) in two contrasting Korean estuary systems, a closed estuary (Geum) (i.e., with an estuary dam at the river mouth) and an open (Seomjin) estuary. A dual isotope (δC and ΔC) approach was applied to surface water samples collected along a salinity gradient in August 2016. Our results indicate that phytoplankton-derived POC was the main contributor to the total POC pool in the reservoir of the Geum estuary, while terrestrial-derived POC predominated the upper Seomjin estuary. A simple binary mixing model using ΔC revealed a higher modern POC contribution (87-90%) in the Geum estuary reservoir than that (77%) of the upper Seomjin estuary. Accordingly, it appears that an estuary dam can alter the source and reactivity of POC in a reservoir, which can be transferred to the adjacent coastal ecosystem.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.marpolbul.2019.110719 | DOI Listing |
Mar Environ Res
September 2025
Department of Marine Ecology and Environment, Gangneung-Wonju National University, Gangneung, 25457, Republic of Korea. Electronic address:
The river transports dissolved and particulate matter to the estuary, where physical and biogeochemical transitions occur. In the river-estuary transition zone (RETZ), phytoplankton response is an effective indicator of environmental variability with their immediate responses. Here, we examine summer-monsoonal variability in productivity and nitrogen uptake of phytoplankton in three major Korean rivers and their estuaries: the Han, Geum, and Yeongsan.
View Article and Find Full Text PDFMar Pollut Bull
March 2024
Division of Environmental Science and Ecological Engineering, Korea University, Seoul 02841, Republic of Korea; OJEong Resilience Institute, Korea University, Seoul 02481, Republic of Korea. Electronic address:
The supply and sources of N and Hg in the Geum estuary of the western coast of Korea were evaluated. Triple isotope proxies (δN, ΔO and δO) of NO combined with conservative mixing between river and ocean waters were used to improve isotope finger-printing methods. The N pool in the Geum estuary was primarily influenced by the Yellow Sea water, followed by riverine discharge (821 × 10 mol yr) and atmospheric deposition (51 × 10 mol yr).
View Article and Find Full Text PDFMar Pollut Bull
February 2024
School of Earth and Environmental Sciences & Research Institute of Oceanography, Seoul National University, Seoul 08826, Republic of Korea. Electronic address:
This study investigated the relationships between phytoplankton assemblages and water contamination by persistent toxic substances (PTSs) and nutrients in an estuary with an artificial dam over one year. The distribution of PTSs, including 15 polycyclic aromatic hydrocarbons, 6 alkylphenols, and 8 metal(loid)s, along with nutrients, exhibited relatively high concentrations with irregular temporal fluctuations in the inner estuary. During winter and spring, phytoplankton communities showed good ecological quality, with an average of 28 species and a density of 1750 cells L.
View Article and Find Full Text PDFEnviron Pollut
December 2021
Department of Marine Sciences and Convergence Engineering, Hanyang University, Ansan 15588, Republic of Korea.
Here, we investigated the characteristics of the environmental multimedia distribution of microcystins (MCs) introduced from freshwater discharge through the estuary dam of the Geum River. In addition, the applicability of a passive sampling device (polar organic chemical integrative sampler, POCIS) for monitoring MCs was evaluated. Surface water, suspended solids (SS), sediments, and oysters were collected from the inner and outer estuary dam.
View Article and Find Full Text PDFMar Pollut Bull
July 2021
Hanyang University, ERICA campus, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan-si, Gyeonggi-do 15588, South Korea. Electronic address:
We investigated a sediment core collected from the Geum Estuary through sedimentological and geochemical analyses. Three lithological units were classified based on sedimentological characteristics. Unit 1 and Unit 3 were geochemically distinct, while Unit 2 was the transitional phase between them.
View Article and Find Full Text PDF