Nitrate flux at the sediment-water interface in the West-Nakdong river estuary SCOPUS KCI

Title
Nitrate flux at the sediment-water interface in the West-Nakdong river estuary
Author(s)
Lee T.-H.; Lee T.
KIOST Author(s)
Lee, Taehee(이태희)
Publication Year
2004
Abstract
Chronic outbreaks of green tide in the Nakdong estuary toll a heavy socioeconomic cost. The paper investigates the influence of sediments on the nitrogen eutrophication, being claimed as the primary cause of green tide. To measure the flux of nitrate at the sediments-water interface, sediment cores were taken in Jan., Mar., May and Sep., 2000 at Noksan located in the West-Nakdong river estuary. The dissolved oxygen was profiled and then the pore water was extracted in situ. Core samples were analyzed for their textural characteristics. Cores were incubated by a novel technique to measure the fluxes of nitrate (NO3 -) and ammonia (NH4+) at the sediment-water interface. The dissolved oxygen was depleted usually within several millimeters in the top sediments. Nitrate started to decrease drastically at the layer where dissolved oxygen was nearly depleted. Nitrate was also exhausted within several centimeters, followed by ammonia build up rapidly. The flux at the sediments-water interface calculated from the pore water concentrations revealed that nitrate was removed from the water column into the sediments. The sediment incubation experiment confirmed the above result. On the other hand ammonia were released from the sediment to the water column. As the incubation went on, however, the nitrate concentration in the overlying water was dropped below that of a top sediment. Then the flux is reversed, i.e., nitrate was released from the sediments to the water column. The implication is that the sediment can supply nitrate to the water column if it falls below a certain level. Thus it is likely that sediments in the eutrophicated river buffers the nitrate concentration in the water column, which leads to a prolonged green tide.
ISSN
1598-141X
URI
https://sciwatch.kiost.ac.kr/handle/2020.kiost/5316
DOI
10.4217/OPR.2004.26.4.635
Bibliographic Citation
Ocean and Polar Research, v.26, no.4, pp.635 - 646, 2004
Publisher
Korea Institute of Ocean Science and Technology
Subject
ammonia; estuarine environment; eutrophication; green alga; nitrate; porewater; sediment-water interface; Asia; Eastern Hemisphere; Eurasia; Far East; Korea; Nakdong River; South Korea; World
Keywords
Ammonia; Flux; Nitrate; Pore water; Sediment incubation; West-Nakdong river
Type
Article
Language
Korean
Document Type
Article
Publisher
Korea Institute of Ocean Science and Technology
Related Researcher
Research Interests

Marine Geochemistry,Marine Environment,Oceanography,해양지화학,해양환경,해양학

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