• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.17 no.4
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• pp.203-224
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• 2012

Definition of estuary and its administrative boundaries is needed for the practical management of estuarine environment. However, the majority of Korean estuaries are lack of scientific data required for defining the administrative boundaries. For this reason, a systematic way to set the boundaries has not been developed so far. This study proposed adaptive and comprehensive criteria in defining the boundary of an estuary based on the available data which includes physiochemical, geographical and topographical characteristics and regional data such as land uses and socio-economic conditions. An estuary boundary is defined with a sequential manner. First of all, according to the estuarine circulation pattern, 463 estuaries in Korea were classified into open estuaries and closed estuaries. Then an individual belonging to each type of estuary is defined an water zone boundary considering the physiochemical, geographical and topographical characteristics and land uses. Finally, a land zone boundary is set along the catchment. According to the proposed criteria, we have delineated 274 estuarine management zones in Korea on a trial basis and found that it was possible to set a boundary reasonably considering the difference of level of available data and regional characteristics in each estuary.

• Proceedings of the KAIS Fall Conference
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• 2009.12a
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• pp.358-362
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• 2009

The coastal zone is the transitional area between land and sea. It plays an important role in the land-sea ecosystem. Unfortunately, most of the world's coastal areas are polluted due to the human being activities. Pollution and development are changing coastal habitats, and feeding and nursery areas are being destroyed, reducing fish and wildlife populations. The pollution in coastal areas is becoming a global environmental problem, more and more attention has been paid to coastal areas. America passed the Coastal Zone Management Act (CZMA) in 1972, and from then, CZMA outlined and conducted the National Coastal Zone Management Program and the National Estuarine Research Reserve System which including 34 projects. And England established "the Crouch & Roach Estuary Project" in 2003, and "South East Coastal and Marine Project" was started in 2007 in responding to the non-point pollutants challenge.

• Korean Journal of Ecology and Environment
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• v.40 no.1
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• pp.40-49
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• 2007

For effective watershed management, we must understand the complex and dynamic relationships of land uses and water quality. Despite numerous studies investigated the relationships between water quality and land use, there are increasing concerns on the geographical variation and lack of spatial integrations in previous studies. We investigated the relationships between land use and water quality characteristics in the Hwa-Sung estuarine reservoir watershed in Korea, which has spatially integrated land uses. The spatial variations of these relationships were also examined using zonal analysis. Water quality parameter were correlated positively with residential and forest and negatively with paddy and upland especially during base flow in the near buffer zone. During storm flow, correlation between land use and water quality was less apparent. Population and livestock density was correlated well to water quality parameter than just number of population and livestock. Relationships across zones, distinguished by distances from streams, were inconsistent and erratic, suggesting that the relationships between remote land uses and water quality may be affected more significantly by sub-basin characteristics than by the land use itself. The watersheds studied are mainly non-urban and their land uses are similar to typical watershed of other estuarine reservoirs, therefore, the correlation developed in this study might be helpful to manage other watersheds of estuarine reservoir. This methodology could be applied to other areas where the watershed characteristics are not significantly different from the study area.

• Ecology and Resilient Infrastructure
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• v.10 no.4
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• pp.171-183
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• 2023

Estuarine wetlands, which form a distinctive brackish water zone, serve as important habitats for organisms that have adapted to and thrive in this environment. Nonetheless, excessive development and utilization result in artificial disruptions that alter the distinctive functions and attributes of estuarine wetlands. To collect the basic data for the conservation of estuarine wetlands with excellent ecosystems, we investigated the vegetation distribution characteristics and biota status of the Taehwagang River Estuarine Wetland. Data from vegetation surveys have shown that 25 plant communities of six physiognomic vegetation types, including willow vegetation, lotic and lentic herbaceous vegetation, floating/submerged vegetation. In the upper reaches, where topographical diversity was high, various types of wetland vegetation were distributed. In terms of biodiversity, a total of 696 species, including 7 endangered wildlife species, were identified. Due to good ecological connectivity, tidal rivers are formed, brackish water species including various functional groups are distributed around this section. The inhabitation of various water birds, such as diving and dabbler ducks, were confirmed according to the aquatic environment of each river section. The collection of ecological information of the Taehwagang River Estuarine Wetland can be used as a framework for establishing the basis for conservation and management of the estuarine ecosystem and support policy establishment.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.4
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• pp.351-361
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• 2010

Among common estuarine submerged plants, seagrasses are the most extensively studied due to their ecological importance in estuarine ecosystems. Seagrass meadows are important biological habitats for a wide variety of marine animals and plants. They are a source of organic carbon for commercially important animals. Furthermore, seagrasses act as nutrient filters in estuarine and coastal marine ecosystems. As such, mapping the distribution of seagrass beds is important for management and conservation strategies. In order to survey the seagrass distribution within the Seomjin Estuary, We directly observed seagrass beds in Kwangyang and Hadong using SCUBA. The distribution area, species composition, morphology, density, biomass and productivity of seagrass meadows were examined. Seagrass meadows were distributed in the intertidal and subtidal zones of the Galsa tidal flats, and in the subtidal zone of the neighboring POSCO area. Patches of Zostera japonica was found at patches at the Galsa tidal flats intermediate point. The total estimated seagrass distribution area of the Seomjin Estuary was $1.84\;km^2$. Of the total, $1.83\;km^2$ was Zostera marina (eelgrass) and $0.01\;km^2$ was Zostera japonica (dwarf eelgrass). Zostera japonica was found in intertidal zones. Zostera marina was found from the intertidal to subtidal zones at a 2 m mean sea level (MSL) depth. The leaf productivity of Zostera marina was $4.47g\;DW\;m^{-2}\;day^{-1}$. The annual production of eelgrass was $1,632\;g\;DW\;m^{-2}\;yr^{-1}$, which corresponds to $731g\;C\;m^{-2}\;yr^{-1}$. The total production of eelgrass was $3,002\;tons\;DW\;yr^{-1}$, which corresponds to $1,343\;tons\;C\;yr^{-1}$.

• Journal of Wetlands Research
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• v.20 no.2
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• pp.181-189
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• 2018

This study was performed to analyze the dynamics and distributional condition of biological community and to support the basic information about the estuarine ecosystem management by using the intensively surveyed results by each taxon experts around Tamjin river. We analyzed the biological diversity, abundance, correlation among species, and ecological characteristics about 11 taxa groups including vegetation, fish, birds, mammals, etc. in the Tamjin river estuarine ecosystem. We classified vegetation types into 7 physiognomic types and 18 communities according to habitat conditions with the physical environments and salinity. In total, 1125 species including 9 species of endangered species were identified in research area. The species composition and distributional characteristics of each taxon were corresponded to the environmental characteristics of the estuarine ecosystem. Especially, the species diversity and distribution were clearly distinguished in the river according to the difference of the environmental factors such as flow rate, salinity, and soil. Despite the disturbance factors such as barrage and levees, the biodiversity and its distribution were evaluated to be high level under the current environmental conditions. However, loss or reduction of wildlife habitat due to reclamation, embankment, barrage installation and expansion of farmland has been identified as a major threat to the diversity and health of the local ecosystem. The results of this study can be used as a basic data to cope with various development pressure and damage crisis of the whole estuaries including Tamjin river.

• Korean Journal of Environmental Biology
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• v.29 no.3
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• pp.212-224
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• 2011

The Yeongsan River estuary, located in the south west coast, was a typical estuary before a dike was constructed in December 1981. After the construction, the water quality and plankton communities are expected to change. We investigated the change of phytoplankton community and environmental properties in the Yeongsan River estuary by comparing the data collected recently with the results reported before and/or shortly after the construction. Concentrations of $NH_4$-N were significantly increased in the freshwater zone. Concentrations of DO at the surface, $NO_2+NO_3$ and $NH_4$-N were increased while the concentrations of $PO_4$ at the surface were decreased in the seawater zone. The number of green algae species was decreased in the freshwater zone. The number of diatom species was decreased while the numbers of green algae and dinoflagellates were increased in the seawater zone. This study can provide information for better management of the Yeongsan River estuary since no comparison study has been documented between the phytoplankton community before and after the construction of the dike in the estuary.

• Journal of the Korean Society for Marine Environment & Energy
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• v.9 no.3
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• pp.131-140
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• 2006

Suspended particulate matter and organic carbon were measured in the Mankyoung river estuary in February, May, July and August 2003. There was a large variance in river discharge between the dry season of February and May and the wet season of July and August. The influx of dissolved organic carbon into the estuary was $8.16{\times}10^2tonC\;month^{-1}$ in the dry season and $5.77{\times}10^3tonC\;month^{-1}$ in the wet season. The influx of particulate organic carbon was $9.37{\times}10^2tonC\;month^{-1}$ and $3.14{\times}10^4tonC\;month^{-1}$ in the dry and wet seasons, respectively. Especially, dissolved organic carbon in the northern part of the site inside the dike was increased in July when torrential rainfall was high. In the research, the distribution of dissolved organic carbon showed conservative behavior with the salinity gradient in the estuary, suggesting that physical mixing between seawater and freshwater dominates the distribution pattern of the dissolved organic carbon in the system. However 60 to 90% of the particulate organic carbon introduced into the estuary was removed from the surface water at the upper estuarine mixing zone of low salinities, showing non-conservative behavior similar with suspended particulate matte r. The completion of the Saemangum Dike is likely to inhibit the exchange of materials between open sea and the Mankyoung estuary. This suggests that the oxidation of organic carbon in the bottom of the estuary may exhaust dissolved oxygen in the confined environment.