• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.2
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• pp.295-307
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• 2021

The Korean Peninsula is surrounded on three sides by the East Sea, West Sea and South Sea which are connected to many rivers and streams, thereby facilitating easy inflow of debris from land. Furthermore, excessive debris inflow to the sea because of active fishing and various recreational activities. Debris entering the sea are weighted over time and settle in the seabed, thus, making direct monitoring of debris impossible and its collection difficult. Uncollected submerged marine debris affects the seabed ecosystem and water quality and can cause ghost fishing and ship accidents, especially due to waste net ropes and waste fishing gears. Therefore, understanding the debris distribution characteristics is necessary to assist quick collection of these debris (waste net ropes and waste fishing gears). Thus, this study conducted a survey of debris deposited in the seas of 39 ports. Furthermore, distribution characteristics and compositions of submerged marine debris were identified by a map prepared through GIS-based spatial analysis of the East Sea. Consequently, 58% of waste tires in the East Sea were concentrated in breakwaters and ship berthing facilities. Moreover, 26 % of waste plastics were distributed outside the port. Identifying the distinct distribution characteristics of submerged marine debris was difficult; however, compared with others, the distribution of waste plastics was possible outside the port. The findings of this study can serve as baseline data to assist the collection of submerged marine debris using the distribution characteristics.

• Journal of Microbiology
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• v.40 no.3
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• pp.234-236
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• 2002

A blue pigment-producing bacterium, Vogesella indigofera, was isolated and quantified for the relationship between its synthesis of a blue pigment and exposure concentrations of $Cr^{6+}$. The concentration of $Cr^{6+}$ and the percentage of blue colonies on agar plates was negatively correlated ($r^{2}$ =-0.8683). Critical concentrations inhibiting bacterial pigment production were found to be between 100-150 $\mu\textrm{g}$ $Cr^{6+}$/ml on agar plates and 200-300 $\mu\textrm{g}$ $Cr^{6+}$/ml in liquid culture. As the blue color is characteristic and easily observable, the bacterium Vogesella indigofera may have potential applications in the detection and monitoring of environmental pollution.

• Journal of the Korean Society of Marine Environment & Safety
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• v.15 no.2
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• pp.79-89
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• 2009

For preliminary diagnosis on current fishing ground environment and basic information for establishment of effective and rational management policy in fisheries resources protection area, water and sediment quality and changes of total area in the 10 marine protection areas designated for fisheries resources management in Korea were assessed. Results showed that environmental quality in these areas has been degraded by pollution sources, coastal utilization and development stress, etc. The pattern and degree of contamination differed by protection areas, suggesting that it is necessary for optimum environmental management plan considering the regional characteristics. The total designated area of protection areas in 2003 changed by $-22.9{\sim}2.4%$, on average -6.4%, compared with the first year of designation; Wando-Doam Bay showd the highest increase rate (2.4%), and Hansan Bay has the highest decrease rate (-22.9%) Decrease rate of land and sea in total area showd 6.1% and 6.6%. An integrated management of environmental data in protection areas is required for systematic assessment. Therefore, the suitable environmental and information management is needed specifically considering the environment characteristics such as development and utilization conditions of land and sea area Furthermore, bemuse urbanization and industrialization threats the junctions of the protection areas, authorized ministry (MIFAFF) should develope and establish monitoring and management procedures based on the related laws.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2019.11a
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• pp.230-232
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• 2019

There is an accelerating need for ocean sensing where autonomous vehicles can play a key role in assisting engineers, researcher and scientists with environmental monitoring and collecting oceanographic data. This paper is performed to develops an autonomous sailing drone to be used as a sensor carrying platform for autonomous data acquisition at Sea. From a sailing drone design viewpoint, it is important to establish reliable prediction methods for sailing drone's resistance. The required power for the propulsion unit depends on the ship resistance and speed. There are three solutions for the prediction of ship resistance as follow analytical methods, model tests in tanks and Computational Fluid Dynamics (CFD). The present paper aims at simulating sailing drone friction resistance using numerical method. The dynamic mesh motion is used to describe the sailing drone movement.

• Journal of the Korea Concrete Institute
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• v.21 no.3
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• pp.359-366
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• 2009

A new life-cycle cost (LCC) evaluation scheme for marine reinforced concrete structures is proposed. In this method, unlike the conventional life-cycle cost evaluation performed during the design process, the life-cycle cost is updated successively whenever new information of the chloride penetration is available. This updating is performed based on the Bayesian approach. For important structures, information required for this new method can be obtained without any difficulties because it is a common element of various types of monitoring systems. Using the new method, the life-cycle maintenance cost of structures can be estimated with a good precision.

• Journal of the Korean Society for Marine Environment & Energy
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• v.17 no.4
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• pp.274-282
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• 2014

The Korean government is considering the implementation of the marine debris pollution abatement technology program (MDPATP) to mitigate the negative impacts of marine debris and systematically manage marine debris through scientific researches such as monitoring and environmental impact assessment of marine debris. In this regard, this study attempts to analyze the economic feasibility of the MDPATP in order to provide policy-maker with useful information. To this end, the indices for economic feasibility such as net present value (NPV), benefit/cost (B/C) ratio, and internal rate of return (IRR) are presented. The results show that NPV, B/C ratio, and IRR are computed to be 45.7 billion won, 2.72, and 17.12%, respectively, which are bigger than 0, 1.0, and 5.5%, and that the MDPATP passes the cost-benefit analysis. Thus, it is concluded that it is socially profitable to conduct the MDPATP.

• Korean Journal of Environmental Biology
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• v.37 no.4
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• pp.474-482
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• 2019

Disease monitoring in wild aquatic animals is necessary to obtain information about disease occurrence, disease agents, and the transmission of diseases between wild and cultured species. In this study, we monitored viral diseases in wild marine fish and crustacea caught by trawl in Korea in April and October 2018. We monitored the viral diseases in 977 fish from 39 different species and 287 crustacea from 14 different species. In fish, we collected kidney and spleen to detect viral hemorrhagic septicemia virus (VHSV), red sea bream iridovirus (RSIV), marine birnavirus (MABV), hirame rhabdovirus (HRV), and lymphocystis disease virus (LCDV). In crustacea, we monitored white spot syndrome virus (WSSV), infectious hypodermal and hematopoietic necrosis virus (IHHNV), taura syndrome virus (TSV), infectious myonecrosis virus (IMNV), yellowhead disease virus (YHDV), and white tail disease virus (WTDV) using pleopods, pereiopods, gills, muscle, and hepatopancreases. Although none of the viral diseases tested in this study were detected in the samples, these results will help disease control between aquaculture species and wild aquatic animals.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.39 no.spc1
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• pp.214-222
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• 2006

Dominant species of macrobenthos were analyzed based on differentiation of three distinct methods: the density based method, the biomass based method and LeBris method, by considering the frequency of occurrence using quantitative data collected over 5 years (1993-1998) at 21 stations in Chonsu Bay. Sedimentary environments as well as species composition and diversity showed the spatial and temporal distribution patterns. The ranks of dominant species as determined by the density based method were more similar to the results by the LeBris method than to those from the biomass based method. Considering the temporal variation, LeBris method were more efficient than any other methods for the determination of dominant species in Chonsu Bay. Lumbrineris longifolia, Theora fragilis, and Moerella jedoensis were recognized by all three methods. A one-way analysis of variance indicated spatial distributions patterns among most of the dominant species. These species showed positive correlations to sedimentary parameters such as mean grain size. However, T. fragilis and Paraprinospio pinnata showed the temporal patterns in their distribution, and were also correlated to the benthic environment, organic content and dissolved oxygen. Some dominant species, e.g., T. fragilis, S. scutata, G. gurjanovae proved to be useful benthic indicators based on the environmental variations determinated by long-term benthic ecological monitoring in Chonsu Bay.

• Korean Journal of Environmental Biology
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• v.35 no.4
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• pp.677-683
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• 2017

The Korean aquaculture industry was generally began in the 1970s and has gradually increased. Now, the number of households is about 7,068 and the scale of an aquaculture farm is about 248,014 ha; the value of all production in the industry is estimated to be about 1602.2 billion won. The aquaculture industry is very valuable and important for future food resources. However, the aquaculture industry was damaged by several marine ecological disturbance causing organisms. The Ascdiella aspersa colonized on the shell of scallop and then scallops were detached from rope. The patterns of damage in the aquacultures were observed in Tongyeong (oyster), Geojedo (oyster), and Gangneung (sea squirt) in June, 2017, as well as in Tongyeong (oyster) in November, 2017 by SCUBA divers. The species Halichondria bowerbanki, Bugula neritina, Mytilus galloprovincialis, Balanus amphitrite, Ascidiella aspersa, Ciona intestinalis, Didemnum sp, Styela plicata in Tongyeong, M. galloprovincialis, A. aspersa, C. intestinalis, D. vexillum, S. plicata in Geojedo, and M. galloprovincialis in Gangneung were all usually found in their farms. The marine ecological disturbance causing organisms gave rise to a reduced number of aquaculture products.

• ALGAE
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• v.23 no.4
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• pp.301-310
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• 2008

The marine benthic algal flora and biomass of Chuja Island, southern coast of Korea, was investigated. The collections of intertidal marine algae were made at two sites, Yecho of Hachujado and Hupo of Sangchujado, from October 2006 to July 2007. A total of 162 species, including 15 green, 47 brown and 100 red algae, were identified in this study. The occurrence of species according to season was abundant during spring to summer and less in autumn. The vertical distribution of intertidal zone in Chujado was characterized by Gloiopeltis spp., Myelophycus simplex, Ishige okamurae, Chondrus ocellatus, Grateloupia elliptica, Hizikia fusiformis and Sargassum spp. The average biomass of macroalgae was measured as 400 g wet wt m$^{-2}$. The dominant species based on the biomass were Sargassum yezoense, S. coreanum and Hizikia fusiformis. ESG II (ecological state group) as an opportunistic species, including sheet form, filamentous form, and coarsely branched form, occurred 85.8% in the intertidal seaweeds. These results provide a baseline for future monitoring studies in the Chuja Island.