• Journal of Korean Society of Coastal and Ocean Engineers
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• v.21 no.6
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• pp.453-461
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• 2009

Camera monitoring of topographical changes of intertidal flat was performed at Daehang-ri mud flat outside Semangeum sea dike No. 1, where creation of mud flat was reported after sea dike construction. Ground survey on the mud flat is often limited only to points or few line surveys because of difficulty of walking and limitation of working hours by flood/ebb. This study uses natures of tide that the water lines moving on the intertidal flat during a flood indicate depth contours between low and high tide. Ground coordinates for the water lines extracted from the consecutive images of intertidal flat are calculated and information of topography is acquired by integrating all the water line data. Analysis of 6 camera monitoring data between September 2005 and September 2009 shows 0.127 m deposition per year on the average and variation of deposition/erosion in space and time.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.2
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• pp.75-83
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• 2009

In order to understand the impacts of the construction of artificial sea dikes on carbon cycle in Samangeum area being a closed environment after April, 2006, we had measured suspended particulate matters, particulate and dissolved organic carbon in the surface water of inner Saemangeum dike from 2003 to 2006. The significant inputs of suspended particulate matter and organic carbon were mainly occurred during the wet season which suggests that most organic matter loading is concentrated within a short period of time inside the dike. The concentrations of particulate matter and organic carbon have gradually increasing every year inside of dike from the Mangyeong river estuary to Saemangeum dike, which has been closed since 2003 after the construction of the 4th dike. The particulate organic carbon increased due to the phytoplankton blooms by eutrophication. If the large portion of particulate organic matter produced in the surface water sink to the bottom sediment, this will cause the anoxic condition in this closed environment.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.3
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• pp.191-199
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• 2007

Seasonal variation in species composition of fish in the Saemangeum Reservoir was determined using seasonal samples collected by an otter trawl from April 2006 to February 2007 after the dike construction, and compared with the data obtained during the dike construction in 2001-2002. A total of 35 species, 8,960 individuals and 53,084.4 g of fish were collected during the study. Of the fish collected, brackish and coastal fishes such as Konosirus punctatus, Synechogobius hasta and Repomucenus lunatus, and migrant fishes such as Engraulis japonicus and Scomberomorus niphonius predominated in abundance accounting for 95% in the total number of individuals. Fish species composition and abundance showed a similar seasonal trend to those in the other western coastal waters of Korea. The resident species were mainly collected in spring and in autumn. The number of species and biomass were high in summer by the large amount of catch of migrating species. Catch was low in winter and only 2 species were collected. A brackish and coastal fish, K. punctatus and two migrant fishes, E. japonicus and S. niphonius were abundantly collected after the dike construction. However, the dominant fishes during the dike construction such as Leiognathus nuchalis, Neosalanx jordani and Chaeturichthys stigmatias were rarely collected. Fish density was $1,149\;inds./10,000m^2\;and\;12,644g/10,000m^2$ during the dike construction, and increased 6 times in the number of individuals ($7,467\;inds./10,000m^2$) and 3 times in biomass ($44,237g/10,000m^2$) after the dike construction. Annual species richness (R) and species diversity (H') decreased from R=0.0160 and H'=2.47 during the dike construction in 2001-2002 to R=0.0038 and H'=1.11 after dike construction in 2006-2006, respectively. These changes seemed to be related to the reduction of the saline area and degradation of water quality in Semangeum Reservoir after the dike construction.