• Korean Journal of Ichthyology
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• v.26 no.4
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• pp.322-330
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• 2014

The fish species and groups were investigated at the four streams in Goseong from September 2011 to August 2012. During the survey period, 17 species from Goseong stream, 18 species from Maam stream, 20 species from Guman stream, and 15 species from Baedun stream of fish were collected. Four creek downstreams were classified into 2 groups which were categorized by the effects of seawater. Group A is Guman and Maam streams with no estuary barrage, with the exchange of freshwater and seawater. On the other hand, group B is Goseong and Beadun streams which was blocked by the estuary barrage and submerged weir. The former group was mainly consisted of peripheral freshwater fish species such as Tridentiger brevispinis, Gymnogobius castaneus, Mugli cephalus, and Acanthogobius flavimanus. The latter one was composed of primary freshwater fish species such as Zacco koreanus, Squalidus gracilis majimae, and Pseudorasbora parva. These results suggest that estuary barrage and submerged weir in the stream could change the natural flow of seawater and freshwater, resulting in change of fish species and groups.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.16 no.2
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• pp.81-96
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• 2011

Sediment oxygen demand(SOD) and denitrification rates were measured in four major estuaries(Suncheon Bay, Seomjin river estuary, Goseong stream estuary and Masan Bay) in south coast of Korean peninsula from March of 2009 to May 2010 to estimate organic matter cleaning capacity. SOD was estimated from the temporal dissolved oxygen concentration change and isotopic pairing technique was employed to measure denitrification. Sediment oxygen demand(SOD) was ranged from -5.1 to 24.6 mmole $O_2m^{-2}d^{-1}$ and denitrification rate was ranged from 0.0 to 3.9 mmole $N_2m^{-2}d^{-1}$in the study area. SOD was the highest in Masan Bay(-2.2 to 19.2, average = 10.2 mmole $O_2m^{-2}d^{-1}$) and Suncheon, Goseong, Tae-an and Seomjin followed. Denitrification was also the highest in Masn Bay(0.0 to 3.9, average = 1.0 mmole $N_2m^{-2}d^{-1}$) and Goseong, Seomjin, Suncheon and Taean followed. The effect of benthic photosynthesis by microphytobenthos on denitrification was evident in some season of Tae-an, Seomjin, and Masn Bay. The increased oxygen level produced by photosynthesis stimulated nitrification without severe adverse effect on denitrification and, as a result, coupled nitrification and denitrification was enhanced in these areas. A difference of seasonal patterns of denitrification at each site depended on relative importance of denitrification on different nitrate source($D_w$: nitrate from water column and $D_n$: nitrated produced during nitrification). Denitrification was maximum during spring in Goseong, Suncheon and Masan Bay. On the contrary, denitrification was the highest during summer in Tae-an and Seomjin estuary.