Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South Korea
In this study, surface water samples were collected at sites located in the lowest reaches of closed (Geum) (i.e. with an estuary dam at the river mouth) and open (Seomjin) estuary systems between May 2016 and May 2018. We analyzed concentrations and stable isotopes of particulate organic carbon (PO...
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2019-12-01
|
| Series: | Environment International |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0160412019318811 |
| _version_ | 1811309814921297920 |
|---|---|
| author | Sujin Kang Jung-Hyun Kim Daun Kim Hyeongseok Song Jong-Sik Ryu Giyoung Ock Kyung-Hoon Shin |
| author_facet | Sujin Kang Jung-Hyun Kim Daun Kim Hyeongseok Song Jong-Sik Ryu Giyoung Ock Kyung-Hoon Shin |
| author_sort | Sujin Kang |
| collection | DOAJ |
| description | In this study, surface water samples were collected at sites located in the lowest reaches of closed (Geum) (i.e. with an estuary dam at the river mouth) and open (Seomjin) estuary systems between May 2016 and May 2018. We analyzed concentrations and stable isotopes of particulate organic carbon (POC) and dissolved organic carbon (DOC) to assess OC sources, to estimate fluxes of riverine OC, and to assess some of the factors driving OC exports in these two contrasting Korean estuary systems. Our geochemical results suggest that the contribution of the phytoplankton-derived POC to the total POC pool was larger in the Geum River than in the Seomjin River. Notably, a heavy riverine algae bloom occurred in the Geum River in August 2016, resulting in a high carbon isotopic composition (−19.4‰) together with low POC/PN ratio (<10) and POC/Chl-a ratio (<100). In contrast, potential DOC sources in both the Geum River and the Seomjin River were a mixture of C3-derived forest soils and cropland organic matter. During the study period, the catchment area-normalized fluxes of POC and DOC were 0.40 × 10−3 tC/km2/yr and 6.5 × 10−2 tC/km2/yr in the Geum River and 5.2 × 10−4 tC/km2/yr and 8.6 × 10−4 tC/km2/yr in the Seomjin River, respectively. It appears that the POC flux was more weakly associated with the water discharge in the Geum River than in the Seomjin River, but the DOC fluxes were in general controlled by the water discharges in both rivers. Accordingly, the estuary dam of the Geum River might be one of the most strongly influencing factors on seasonal patterns in POC fluxes into the adjacent coastal seas, strongly modifying water residence times and thus biogeochemical processes. Keywords: Estuary dam, Riverine organic carbon, Geum River, Seomjin River |
| first_indexed | 2024-04-13T09:47:38Z |
| format | Article |
| id | doaj.art-7e52aeb10c814614bed338c148250020 |
| institution | Directory Open Access Journal |
| issn | 0160-4120 |
| language | English |
| last_indexed | 2024-04-13T09:47:38Z |
| publishDate | 2019-12-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Environment International |
| spelling | doaj.art-7e52aeb10c814614bed338c1482500202022-12-22T02:51:41ZengElsevierEnvironment International0160-41202019-12-01133Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South KoreaSujin Kang0Jung-Hyun Kim1Daun Kim2Hyeongseok Song3Jong-Sik Ryu4Giyoung Ock5Kyung-Hoon Shin6Hanyang University ERICA, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan-si, Gyeonggi-do 15588, South KoreaKOPRI Korea Polar Research Institute, 26 Songdomirae-ro, Yeonsu-gu, Incheon 21990, South Korea; Corresponding authors.Hanyang University ERICA, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan-si, Gyeonggi-do 15588, South KoreaGraduate School of Analytical Science and Technology, Chungnam National University, Daejeon 34134, Republic of KoreaDepartment of Earth and Environmental Sciences, Pukyong National University, Busan 48513, Republic of KoreaDivision of Ecosystem Assessment, National Institute of Ecology, Seocheon 33657, Republic of KoreaHanyang University ERICA, 55 Hanyangdaehak-ro, Sangnok-gu, Ansan-si, Gyeonggi-do 15588, South Korea; Corresponding authors.In this study, surface water samples were collected at sites located in the lowest reaches of closed (Geum) (i.e. with an estuary dam at the river mouth) and open (Seomjin) estuary systems between May 2016 and May 2018. We analyzed concentrations and stable isotopes of particulate organic carbon (POC) and dissolved organic carbon (DOC) to assess OC sources, to estimate fluxes of riverine OC, and to assess some of the factors driving OC exports in these two contrasting Korean estuary systems. Our geochemical results suggest that the contribution of the phytoplankton-derived POC to the total POC pool was larger in the Geum River than in the Seomjin River. Notably, a heavy riverine algae bloom occurred in the Geum River in August 2016, resulting in a high carbon isotopic composition (−19.4‰) together with low POC/PN ratio (<10) and POC/Chl-a ratio (<100). In contrast, potential DOC sources in both the Geum River and the Seomjin River were a mixture of C3-derived forest soils and cropland organic matter. During the study period, the catchment area-normalized fluxes of POC and DOC were 0.40 × 10−3 tC/km2/yr and 6.5 × 10−2 tC/km2/yr in the Geum River and 5.2 × 10−4 tC/km2/yr and 8.6 × 10−4 tC/km2/yr in the Seomjin River, respectively. It appears that the POC flux was more weakly associated with the water discharge in the Geum River than in the Seomjin River, but the DOC fluxes were in general controlled by the water discharges in both rivers. Accordingly, the estuary dam of the Geum River might be one of the most strongly influencing factors on seasonal patterns in POC fluxes into the adjacent coastal seas, strongly modifying water residence times and thus biogeochemical processes. Keywords: Estuary dam, Riverine organic carbon, Geum River, Seomjin Riverhttp://www.sciencedirect.com/science/article/pii/S0160412019318811 |
| spellingShingle | Sujin Kang Jung-Hyun Kim Daun Kim Hyeongseok Song Jong-Sik Ryu Giyoung Ock Kyung-Hoon Shin Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South Korea Environment International |
| title | Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South Korea |
| title_full | Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South Korea |
| title_fullStr | Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South Korea |
| title_full_unstemmed | Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South Korea |
| title_short | Temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems: Geum and Seomjin, South Korea |
| title_sort | temporal variation in riverine organic carbon concentrations and fluxes in two contrasting estuary systems geum and seomjin south korea |
| url | http://www.sciencedirect.com/science/article/pii/S0160412019318811 |
| work_keys_str_mv | AT sujinkang temporalvariationinriverineorganiccarbonconcentrationsandfluxesintwocontrastingestuarysystemsgeumandseomjinsouthkorea AT junghyunkim temporalvariationinriverineorganiccarbonconcentrationsandfluxesintwocontrastingestuarysystemsgeumandseomjinsouthkorea AT daunkim temporalvariationinriverineorganiccarbonconcentrationsandfluxesintwocontrastingestuarysystemsgeumandseomjinsouthkorea AT hyeongseoksong temporalvariationinriverineorganiccarbonconcentrationsandfluxesintwocontrastingestuarysystemsgeumandseomjinsouthkorea AT jongsikryu temporalvariationinriverineorganiccarbonconcentrationsandfluxesintwocontrastingestuarysystemsgeumandseomjinsouthkorea AT giyoungock temporalvariationinriverineorganiccarbonconcentrationsandfluxesintwocontrastingestuarysystemsgeumandseomjinsouthkorea AT kyunghoonshin temporalvariationinriverineorganiccarbonconcentrationsandfluxesintwocontrastingestuarysystemsgeumandseomjinsouthkorea |