• Title/Summary/Keyword: coastal environment

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Screening of Differentially Expressed Genes in Diesel Oil-exposed Marine Fish Using DD-PCR

  • Woo, Seon-Ock;Yum, Seung-Shic;Yim, Un-Hyuk;Lee, Yaek-Kyun
    • Molecular & Cellular Toxicology
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    • v.2 no.4
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    • pp.251-256
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    • 2006
  • The exploration of genes which expressions are changed by exposure to ecotoxicants or pollutants can provide the important information about the reaction mechanisms in the body as well as adaptation to exterior stimulus or environmental changes. Also they can be developed as biomarkers for the detection of environmental pollution. Differential display polymerase chain reaction (DD-PCR) technique has been usefully used to hunt the clones which expressions are up-regulated or down-regulated by exterior changes and this study aimed to search for those clones in diesel oil-exposed rockfish (Sebastes schlegeli) using DD-PCR. The RNA isolated from liver of 20 ppb diesel oil-exposed rockfish was used for screening of the differentially displayed genes and total 44 differentially expressed genes (DEG) are detected then their nucleotide sequences were analyzed. The present data provided the general information about the effect of diesel oil contamination on marine organism and further more the primary step in development of new biomarkers for marine environmental pollution or ecotoxicological stresses.

Sediment Toxicity of Industrialized Coastal Areas of Korea Using Bioluminescent Marine Bacteria

  • Choi, Min-Kyu;Kim, Seong-Gil;Yoon, Sang-Pil;Jung, Rae-Hong;Moon, Hyo-Bang;Yu, Jun;Choi, Hee-Gu
    • Fisheries and Aquatic Sciences
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    • v.13 no.3
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    • pp.244-253
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    • 2010
  • The quality of marine sediments from the industrialized coastal areas of Korea (Ulsan Bay, Masan Bay, and artificial Lake Shihwa) was investigated using a bacterial bioluminescence toxicity test. Sediment toxicity results were compared with the levels of chemical contamination (trace metals, organic wastewater markers, acid volatile sulfides, total organic carbon). Effective concentration 50% (EC50) of sediments ranged from 0.014 to 1.126 mg/mL, which is comparable to or lower than values in contaminated lakes, rivers, and marine sediments of other countries. Sediment reference index (SRI) ranged from 13 to 1044, based on the EC50 of the negative control sample. Mean average SRI values in Masan Bay and Lake Shihwa were approximately 8 and 9 times as high as that in Ulsan Bay, indicating higher sediment toxicity and greater contamination in the two former regions. Sediment toxicity were strongly associated with the concentrations of some chemicals, suggesting that this test may be useful for determining potential chemical contamination in sediments.

Influence of roadkill during breeding migration on the sex ratio of land crab (Sesarma haematoche)

  • Ryu, Mi;Kim, Jae Geun
    • Journal of Ecology and Environment
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    • v.44 no.4
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    • pp.207-211
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    • 2020
  • Adult land crabs generally live on land while their larvae live in the sea. In the case of Sesarma haematoche, female crabs migrate from land to sea to release the larvae at the high tide of syzygy night. Artificial structures along coastal areas are being obstacles for the migration of land crabs and causing synchronized roadkills on coastal roads during breeding migration. In this research, we compared the sex ratios of crab populations in coastal areas with coastal roads and uninhabited island areas with no road. The proportion of females in inland habitats with coastal roads was significantly smaller than island habitats. In particular, females are exposed to the risk of annually repeated roadkills, and the proportion of females decreases rapidly with their growth. If this tendency is general for land crab populations in the coastal areas with roads, significant road mortality of female land crabs during breeding migration can lead to severe population decline in coastal areas. Therefore, it is necessary to take an action to save land crabs crossing coastal roads.

The Mitigating Effects of Seaward Dune Reinforcement Against Coastal Erosion in Dasa-ri, Chungcheongnam-do, South Korea (해안사구 모래보강을 통한 해안침식 저감 효과 - 충청남도 다사리 사구를 사례로 -)

  • Kong, Hak-Yang;Park, Sung-Min;Shin, Young Kyu;Choi, Kwang Hee
    • Journal of The Geomorphological Association of Korea
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    • v.25 no.4
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    • pp.37-47
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    • 2018
  • Coastal sand dunes have been regarded as natural defenses to protect hinterland from disasters such as storm surge and typhoons. However, many dunes are not well-deserved in South Korea because of imprudent land development or inappropriate measures after coastal erosion. Lately, beach nourishment and dune reinforcement are emphasized as the effective and environmentally sustainable solution for the coastal protection. They are regarded good strategies to keep landscapes for a time, with little side effects. However, there is little knowledge on the construction methods including proper design and time plans for the best results.In addition, the effects of dune reinforcement in the field should be tested.In thisstudy, we performed sand filling in an eroded dune scarp and surveyed topographic changes in the beach-dune system, which is located along Dasa-ri coast, Chungnam Province, South Korea. Using a network RTK-GPS and drone-based aerial photographs, we analyzed the temporal and spatial changes in the area, before and after the reinforcement. As a result, the dune reinforcement seems to be helpful to mitigates the coastal erosion and to prevent the coastline retreat at least for one year.

Coastal upwelling observed off the East coast of Korea and variability of passive sound detection environment (동해 연안에서 관측된 용승현상과 수동 음탐환경의 변화)

  • Sang-Shin, Byun;Chang-Bong, Cho
    • The Journal of the Acoustical Society of Korea
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    • v.41 no.6
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    • pp.601-609
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    • 2022
  • In August 2007, coastal upwelling occurred off the east coast of Korea, and vertical water temperature and salinity data were obtained from a real-time surface ocean buoy. Based on the time series observation data, a vertical sound velocity structure was calculated before, during, and after the occurrence of the coastal upwelling, and how the coastal upwelling affects the sound propagation and detection environment through acoustic modeling considering the horizontal scale and actual seabed topography. As a result of comparing and analyzing the low-frequency (500 Hz) sound transmission loss and the target detection range by depth using the parabolic equation model, it was analyzed that if coastal upwelling occurs, a detection gain of up to about 10 dB can be expected. In addition, through this study, it was confirmed that the characteristics of sound propagation can be greatly changed even in a short period of about 2 to 3 days before and after coastal upwelling.

Numerical Simulation of Effects of Atmospheric Flow Fields Using SurFace Observational Data on Dispersion Fields of Air Pollutants in Gwangyang Bay (광양만권역에서의 자료동화된 대기 유동장이 대기 오염 물질의 확산장에 미치는 영향에 관한 수치모의)

  • Lee Hwa Woon;Won Hye Young;Choi Hyun-Jung;Kim Hyun Goo
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.2
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    • pp.169-178
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    • 2005
  • A critical component of air pollution modeling is the representation of atmospheric flow fields within a model domain, since an accurate air quality simulation requires an accurate portrayal of the three-dimensional wind fields. The present study investigated data assimilation using surface observational data in the complex coastal regions to simulate a realistic atmospheric flow fields. Surface observational data were categorized into three groups (Near coastal region, Far coastal region 1, Far costal region 2) by the locations where the sites are. Experiments were designed according to the location of observational stations and MM5/CALPUFF was used. The results of numerical simulation of atmospheric flow fields are used as input data for CALPUFF which predicts dispersion fields of air pollutants. The result of this study indicated that data assimilation using data in the far coastal region 2 provided an attractive method for generating realistic meteorological fields and dispersion fields of air pollutants in Gwangyang area because data in the near coastal region are variable and narrow representation.

Long-term Paradigm Analyses of Chlorophyll a and Water Quality in Reservoir Systems

  • Bach, Quang-Dung;Shin, Yong-Sik;Song, Eun-Sook
    • Korean Journal of Ecology and Environment
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    • v.42 no.4
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    • pp.432-440
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    • 2009
  • During the period of past fifteen years (1992~2006), variations of chlorophyll a in relation with water quality in freshwater reservoirs were investigated. This study compared total nitrogen (TN), total phosphorus (TP), chlorophyll a, Secchi depth (SD) and total suspended solids (TSS) between terrestrial freshwater reservoir and coastal freshwater reservoir systems based on their location. Regression analyses (linear and non-linear regressions) were applied for all study sites to examine relationship and interaction of these factors in the freshwater systems from in-land to coasts. The results demonstrated that chlorophyll a was significantly correlated to total phosphorus ($R^2=0.94$, P<0.0001) and was remarkably related to TSS increase ($R^2=0.63$, P<0.0001) in the selected reservoirs. The TN : TP ratio in the reservoir systems was higher than Redfield ratio (16 : 1) indicating that the reservoirs are potentially experiencing P limitation. Water quality of coastal freshwater reservoir system was more significantly decreased than the reservoirs located in in-land during the past fifteen years. The strict management of nutrient discharge into freshwater systems should implemented in the coastal reservoirs since the freshwater is introduced into coastal estuarine systems.

A Study on the Cost Benefit Analysis Model of Vessel Traffic Services(II) (선박교통관리제도의 비용편익분석모델에 관한 연구(II))

  • 정재용;박진수
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.7 no.3
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    • pp.29-40
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    • 2001
  • The introduction of coastal vessel traffic services enables vessels in coastal waters to navigate in safety or to get her position with ease and prevents the vessel from becoming cause of casualties. But it needs relatively huge amount of cost to construct and operate and maintain. Thus we must be checked with economical adequacy of the the proposed coastal vessel traffic services by comparing the cost of the construction, operation and maintenance with the expected benefit made by the expected decrease in marine casualties. In previous paper, a proper cost-benefit analysis model for the Korean practice will be suggested. In this Paper, the proposed the cost-benefit analysis model of coastal vessel traffic services was applied to the Koje coastal waters 20mi1es from the top of Maemul-Do and Yokchi-Do. As the result, we confirmed the propriety of the cost-benefit analysis with the application of the proposed model to Koje waters. Also, it is verified that the introduction of coastal vessel traffic services, as proposed, is adequate and economical. The cost-benefit analysis model proposed in this study could be used to investigate the economic Propriety of new aids to navigation and traffic safety facilities in the future.

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Risk assessment for fisher's safety in coastal composite fishing vessels (연안복합 어선원의 안전 위험도 평가)

  • LEE, Yoo-Won
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.55 no.2
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    • pp.145-151
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    • 2019
  • The coastal composite fishery has the highest rate of around 30.0% in registered fishing vessels of Korea for the last three years. The risk analysis for the fisher's safety of coastal composite fishing vessels was conducted to serve as a basic data for improving the healthy and safe working environment of fisher using fisher's occupational accidents of the national federation of fisheries cooperatives (NFFC) from 2016 to 2018 (n = 1,105). As a result, the occupational accident occurrence rate of coastal composite fishery was 3.76% in all industries, 7.8 times the rate of that. In addition, death and missing rate was found to have a serious level management to 10.10‱. Among the accidents, 76.0% occurred at sea. The slipping, others and contact with machinery or fishing gear occurred more frequently in order in the frequency of accident occurrence pattern. In the risk assessment using frequency and severity, slipping, contact with machinery and others showed high risk during fishing. The results are expected to contribute to identification and assessment of safety hazard occurred in coastal composite fishing vessels.