• Korean Journal of Ecology and Environment
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• v.47 no.3
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• pp.202-213
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• 2014

More than half of all the tidal flats and islands in South Korea are located in Jeonnam. Shinangun accounts for a large amount of these tidal flats and island. This study assessed the value of ecosystem services for 14 administrative units (2 'eup' and 12 'myeon') that have around 1,000 islands in Shinangun, using the method described by Costanza et al. (1997). The assessment involved examining the land use types in Shinangun in relation to ecosystem services value. The finding showed that the tidal flat areas had the highest value of ecosystem services in most of the islands of Shinangun, in particular in Aphae-eup and Jido-eup. The study illustrates how quantitative analysis of land use patterns can help local governments like Shinangun to formulate policy for conservation and sustainaable use of ecosystem services. Especially, tidal flat areas are unique and fragile ecosystem, so it is very importat to make strategies for sustainable development in bioculturally diverse areas. Some suggestions regarding landscape planning in Shinangun are provided.

• Journal of Wetlands Research
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• v.21 no.1
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• pp.84-94
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• 2019

The Seocheon and Yubu Island mudflats in Geum Estuary are important stopover sites for migratory birds as energy supplementation area in the East Asia-Australasian Flyway. Benthic invertebrates in the tidal flats are important food resources for the migratory birds. In other words, benthic invertebrates in the tidal flats play an important ecological role in energy flow. This study was conducted to investigate the relationship between benthic invertebrate assemblages and environmental factors in Seocheon and Yubudo tidal flats in the Geum Estuary. As a result of the benthic invertebrate assemblage during the fall migration season, the total species number was 147, density and biomass were $1,772{\pm}1,342individuals/m^2$ and $445.1{\pm}807.6g/m^2$, respectively. Based on the appearance species and the density data, the result of analysis of mutual similarity among sampling sites was divided into two groups. Group A was the Macrophthalmus-Heteromastus community and Group B was the Spio-Urothoe-Mandibulophoxus community. Group B showed higher mean species number, density and biomass than Group A. The BIO-ENV analysis showed that the benthic invertebrate assemblages were most affected by the combination of sand content % and sediment sorting (${\rho}=0.500$). The variables of significant relationship with species number and biomass were sediment sorting (p=0.015) and the pore water DO(Dissolved Oxygen, p=0.003) in sediment, respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.28 no.4
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• pp.143-157
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• 2023

This study confirmed the characteristics of macrobenthic community due to anthropogenic environmental changes in the Boryeong Jugyo tidal flat, where the habitat of manila clam (Ruditapes philippinarum) and mud shrimp (Upogebia major) is separated. The total number of occurring species was 55 during the study period with an average habitat density of 338 ind./m² and a biomass of 212.2 gWWt/m². The number of occuring species increased from 27 species at the upper flat to 37 species at the lower flat, and the dominant species differed by tide levels (Upper: Leonnates persica, Middle: Heteromastus filiformis, Lower: R. philippinarum). The macro-benthic community sturctures of the top 10 species using cluster analysis and nMDS were divided into two groups, focusing on Manila clam culture farm of lower flats and middle flats with high habitat density, reflecting the influence of specific species. The sediment composition of the U. major habitat space fluctuated highly, but it was maintained annually, and the sorting coefficient was 2.1 𝜑, and the proportion of the same particle size was increased. In particular, because the middle flat has a dense anthropogenic impact, a dominant species, H. filiformis dominated and revealed a relationship with the density of burrow holes of U. major, which is considered to be a biological interaction between these two macrofauna in this tidal flat.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.48 no.1
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• pp.104-115
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• 2015

This study was conducted during April-June in 2008 and 2010, following the Taean Oil Spill. We measured year-to-year changes in benthos species abundances and composition in 16 intertidal zone regions of Chungcheongnam-do. In total, 154 species were found 2008 and 134 in 2010; the mean abundance per area was $403ind./m^2$ and $242ind./m^2$, respectively. In 2008, the 10 dominant species included four species of arthropods, three species of annelids, and three species of mollusks. In 2010, dominant species included five species of annelids, three species of mollusks, one species of arthropods, and one other species. We used bray-curtis similarity to group species and found two groups in 2008 and five in 2010, complementing our NMDS analysis. Finally, we tested correlations between abiotic and biotic factors, and implemented a BIO-ENV analysis, which showed that sediment type, MZ (Phi), and organic content are important environmental factors affecting benthos in the Chung-nam tidal flats.

• Journal of Environmental Science International
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• v.16 no.7
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• pp.847-853
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• 2007

In Korean coastal areas, land reclamations are main development projects that should be based on environmental impact assessment(EIA), because those human interventions can change coastlines, damage tidal flats, and pollute adjacent areas to threat seafood safety and devaluate overall ecosystem service value. Existing procedures of the EIA for land reclamation projects were diagnosed and evaluated to enhance them. Problems were identified in the designation of survey areas, the consistency in survey sites and periods, the standardization of survey methods and reports, the confidence of survey results and the verification of predictions. Lack of integration was noticeable and could be improved by synthesizing different assessments from topography geography, marine physics, marine chemistry and marine biology. We suggest that successful precautionary marine environment management requires readjusting the cost of EIA, recruiting experts in marine environment, constructing database and establishing specialized assessment system.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.1
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• pp.1-12
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• 2008

The prohibition of usage of tributyltin (TBT) compounds and the legal usage of new antifouling agents have changed the Korean costal environments in recent. 39 sampling sites of southwestern tidal flats were chosen in order to investigate the concentration of antifouling agents, and results in 2006 were compared with previous results in 1998. The concentrations of TBT compounds in most of sites except Incheon (It1) have been drastically decreased. Interestingly, In Jebudo (Jt2), Mokpo(MOt4) and Suncheon(SUt3) sites were detected as below the limit of detection and it is because of the legal restriction of TBT compounds. However, in most of the sampling sites in Korea, new antifouling agents, viz. Irgarol 1051, Dichlofluanid and Chlorothalonil, were detected. In particular, Irgarol 1051 was detected with high concentrations. In Jebudo (Jt4), a high concentration of Irgarol 1051 of 159.45 ng $g^{-1}$(dry wt) was detected. We were able to observe that the concentration of TBT compounds are has gradually been reduced whereas the new major antifouling agents are easily detected in most Korean tidal flats.

• Journal of Wetlands Research
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• v.6 no.1
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• pp.57-72
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• 2004

Macrobenthic fauna were studied on a tidal flat in Garolim Bay in July 2002, in order to understand their spatial distribution with the surface sediment types. Forty-nine stations were set on the tidal flat. A total of 147 species was sampled with the mean density of $1,140ind./m^2$ and the mean biomass of $157.2g/m^2$. The polychaetes were speices- and density-dominant faunal group with 64 species and the mean density of $791ind./m^2$. Mollusks were biomass-dominant faunal group with $132.0g/m^2$. Major dominant species were two polychaetes, Mediomastus californiensis with the mean density of $374ind./m^2$ and Heteromastus filiformis with $224ind./m^2$. Also mollusks such as Umbonium thomasi, Batillaria cumingi and Ruditapes philippinarum was relatively high in the mean density, showing the density of 45, 42, $32ind./m^2$ respectively. Especially, U. thomas was distributed in the mouth of the bay, where sediment grain size is rather coarse, and R. philippinarum at near tidal channel. Based on the cluster analysis, the macrobenthic community on the tidal flat was classified into seven station groups depending on the benthic environmental parameters(sediment types). Compared with other Korean tidal flats, species richness of Garolim tidal flats is more and less low.

• Journal of the Korean Society of Marine Environment & Safety
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• v.23 no.7
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• pp.869-877
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• 2017

Recently, Gomso Bay saw a decrease in the production of manila clam, which accounted for 17.8 % of production across the whole country in 2015, while Geunso Bay saw an increase that raised its contribution to 49.1 %. The tidal flats in these bays are inhabited by various benthos, and material flows in and out according to the tide. It is essential to understand the mass balance of these regions while giving consideration to the characteristics of these tidal flats. In this study, we compared areas where aquaculture farms were located in Gomso Bay with those without from May to August 2015. We divided the region into three sea areas (Sector I, Sector II, and Control), and the mass balance was estimated using the LOICZ model. As a result, the DIP of Sector II in Gomso Bay and another region in Geunso Bay, where a manila clam farm was located, were found to be -207.2 kg/day and 77.2 kg/day. The DIN was -4,996.7 kg/day and 926.6 kg/day. These results suggest that Gomso Bay han a higher density than Geunso Bay, which is thought to be mainly due to the feeding action of organisms. Therefore, in order to maintain a healthy tidal flat ecosystem and to sustain the production of manila clams, sustainable management to reduce the high density of tidal flat farms is necessary.

• Korean Journal of Remote Sensing
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• v.40 no.3
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• pp.295-305
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• 2024

This study aims to analyze the micro-sedimentary structures of the Hwangdo tidal flats using ultra-high resolution unmanned aerial vehicle (UAV) data. Tidal flats, located in the transitional area between land and sea, constantly change due to tidal activities and provide a unique environment important for understanding sedimentary processes and environmental conditions. Traditional field observation methods are limited in spatial and temporal coverage, and existing satellite imagery does not provide sufficient resolution to study micro-sedimentary structures. To overcome these limitations, high-resolution images of the Hwangdo tidal flats in Chungcheongnam-do were acquired using UAVs. This area has experienced significant changes in its sedimentary environment due to coastal development projects such as sea wall construction. From May 17 to 18, 2022, sediment samples were collected from 91 points during field surveys and 25 in-situ points were intensively analyzed. UAV data with a spatial resolution of approximately 0.9 mm allowed identifying and extracting parameters related to micro-sedimentary structures. For mud cracks, the length of the major axis of the polygons was extracted, and the wavelength and ripple symmetry index were extracted for ripple marks. The results of the study showed that in areas with mud content above 80%, mud cracks formed at an average major axis length of 37.3 cm. In regions with sand content above 60%, ripples with an average wavelength of 8 cm and a ripple symmetry index of 2.0 were formed. This study demonstrated that micro-sedimentary structures of tidal flats can be effectively analyzed using ultra-high resolution UAV data without field surveys. This highlights the potential of UAV technology as an important tool in environmental monitoring and coastal management and shows its usefulness in the study of sedimentary structures. In addition, the results of this study are expected to serve as baseline data for more accurate sedimentary facies classification.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.4
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• pp.500-509
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• 2021

This study investigated the characteristics of a macrobenthos community and sediment environment and assessed the health of tidal flats along the west coast of Korea. A survey was conducted from Ganghwa-do to Mokpo, Jeollanam-do in April (spring) and August (summer) 2017, and April (spring) 2018. The sediment grain sizes in the Chungcheongnam-do region were coarser, and the sediment in the Gyeonggi-do·Incheon, Jeollanam-do, and Jeollabuk-do regions were finer. A total of 140 macrobenthic species were collected from this study and using a cluster similarity analysis of the macrobenthos community, they were divided into four groups. Group2 was associated with Manila clam farm stations, and Ruditapes phillipinarum, Nephtys polybranchia and Lumbrineris nipponica were dominant. Group4 included some sites with finer sediment composed relatively, and Eteone longa and Nemertea unid. appeared at a high frequency. From the health assessment of the western tidal flat, the ISEP and BHI indices had a "High status," and the AMBI index had a "Good status." In conclusion, the tidal flats along the west coast of Korea have good ecological health. However, pollution indicator species such as Theora lata and Capitella capitata have appeared in some areas. Therefore, periodic administration and interventions are necessary to prevent deterioration of the tidal flat environment.