• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.467-479
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• 2021

The distribution and abundance of fish eggs and larvae were investigated from February to December 2020 along the coastal waters of Korea. The eggs and larvae were identified using the mitochondrial DNA cytochrome c oxidase subunit I (mtDNA COI) and 16s rRNA gene. During the study period, eggs of overall 45 taxa belonging to 26 families were collected and larvae of overall 39 taxa belonging to 23 families were collected. In Yeongil Bay, eggs of Engraulis japonicus, which accounted for 83.9% of the total population, was the most dominant species, followed by Sardinops sagax (4.0%), Repomucenus valenciennei (3.8%) and E. japonicus larvae, which accounted for 34.9% of the total population. These were followed by Sebastiscus marmoratus (31.0%). In Gomso Bay, E. japonicus eggs accounted for 61.7% of the total population, followed by Sillago japonica (14.0%), Johnius grypotus (8.8%) and Pholis fangi larvae, which accounted for 53.5% of the total population, followed by Ammodytes personatus (34.1%). In Jinhae Bay, E. japonicus eggs accounted for 86.0% of the total population, followed by Leiognathus nuchalis (4.1%), Konosirus punctatus (3.7%) and E. japonicus larvae, which accounted for 48.7% of the total population, followed by Parablennius yatabei (21.6%).

• Ocean and Polar Research
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• v.43 no.3
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• pp.179-192
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• 2021

In this study, an integrated wave model from global to coastal scales was developed to improve the operational wave prediction performance of the Korean Meteorological Administration (KMA). In this system, the wave model was upgraded to the WaveWatch III version 6.07 with the improved parameterization of the source term. Considering the increased resolution of the wind input field and the introduction of the high-performance KMA 5^th Supercomputer, the spatial resolution of global and regional wave models has been doubled compared to the operational model. The physical processes and coefficients of the wave model were optimized for the current KMA global atmospheric forecasting system, the Korean Integrated Model (KIM), which is being operated since April 2020. Based on the sensitivity experiment results, the wind-wave growth parameter (β_max) for the global wave model was determined to be 1.33 with the lowest root mean square errors (RMSE). The value of β_max showed the lowest error when applied to regional/coastal wave models for the period of the typhoon season when strong winds occur. Applying the new system to the case of August 2020, the RMSE for the 48-hour significant wave height prediction was reduced by 13.4 to 17.7% compared to the existing KMA operating model. The new integrated wave prediction system plans to replace the KMA operating model after long-term verification.

• Ocean and Polar Research
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• v.43 no.4
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• pp.255-267
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• 2021

To understand the composition and community changes of benthic species by water depth (5 m, 20 m, 30 m) in the cage facilities, net substrate made of fish cages were installed at intervals of 2 months from March to September 2019, which is the main period of sessile organism recruitment. Water temperature and salinity varied in the ranges of 1~5℃ and 1~4 mg/L at 5 m from June to August, respectively, and less difference was observed according to water depth in other investigation periods. A total of 37 benthic animals were recruited, and Kamptozoa unid., Caprella scaura and Jassa slatteryi were verified during the entire study period. Mytilus galloprovincialis, a Mediterranean mussel, showed seasonality dominant only from spring to early summer (March to July). The community structure classified by temporal and spatial factors, and Bugula neritina, Kamptozoa unid., and Sertularella sp. contributed to the formation of the community. The depth of 5 m was exposed to environmental changes in water temperature and salinity temporally, so there was a seasonal variation in the composition of the sessile organism, but at depths of 20 m and 30 m, there was less significant environmental change and it showed relatively stable than 5 m.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.566-573
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• 2021

In this study, safety management procedures were developed based on domestic and foreign guidelines and related maritime law to ensure the safe development and implementation of smart autonomous ship technology and Samsung Heavy Industry. The safety management procedure was developed according to the guidelines for (MASS) sea trials (MSC.1/Circ.1604, Annex: Interim guidelines for MASS trials), proposed by International Maritime Organization (IMO) for the relevant authorities and stakeholders of MASS to properly conduct tests of systems and infrastructure related to safety and environmental protection. The developed safety management procedure applies to the maritime demonstration test of a system applying autonomous navigation element technology mounted as a navigation aid on a ship operating under a watch system, while complying with the environmental protection and navigation safety of the coast of Korea.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.5
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• pp.639-646
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• 2021

In this study, we located concrete substratum covered by oyster shells in the coastal area of Gijang-gun, Busan, South Korea, and monitored changes in coverage of macroalgae for approximately a year from January 2020 to determine the potential for sea forest restoration and resourceization of the oyster shells. At the start of monitoring, we observed that macroalgae coverage of the oyster-shell-covered concrete substratum (treatment) was 10 - 80 %, whereas no macroalgae were attached to the normal concrete substratum (control). By November, macroalgae coverage of the treatment had increased by 49 % compared to that of the control. We concluded that covering oyster shell on a sea forest reef can promote macroalgae establishment and the possibility of sea forest restoration by the resourceization of oyster shells.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.4
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• pp.397-403
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• 2021

Polycyclic Aromatic Hydrocarbons (PAHs) were analyzed and safety evaluation was carried out in Korean coastal area. The target congeners were benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene, and chrysene. The method of analysis was significant. The highest PAHs 4 congener concentrations (12.2 ㎍/kg) was found in the mussel of Gangwon area. Comparison among the average concentration of PAHs for each congener showed that, benzo[a] anthracene was found in mussel (0.276 ㎍/kg), oyster (0.463 ㎍/kg), ark shell clam (1.92 ㎍/kg), and chrysene was found in mussel (0.848 ㎍/kg), oyster (1.36 ㎍/kg), scallop (0.489 ㎍/kg), sea squirt (3.07 ㎍/kg), and ark shell clam (0.449 ㎍/kg). In addition, benzo[b]fluoranthene was found in mussel (0.253 ㎍/kg), scallop (0.244 ㎍/kg), and sea squirt (1.64 ㎍/kg). The most hazardous benzo[a]pyrene was found in mussel (0.147 ㎍/kg), and scallop (0.244 ㎍/kg), it was not detected in the other shellfishes. However, all the PAHs levels recorded in this study did not exceed international MRLs. There was no significant difference among the PAHs concentration in shellfish based on sampling area or species. Body exposure was calculated based on PAHs concentration and intake rate. The results of this study indicated that PAHs in shellfish were within acceptable safe levels.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1229-1234
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• 2021

GOCI-II, which succeeded the mission of GOCI, was successfully launched in February 2020 and is in operation. GOCI-II is expected to be highly useful in a wide range of fields, including detailed changes in the coastal seawater environment using improved spatial and spectral resolution, increased number of observation and full disk observation mode. This special issue introduces the assessment of the current GOCI-II data quality and the studies on the accuracy improvement and applications at this time of one year after launch and data disclosure. We expect that this issue can be an opportunity for GOCI-II data to be actively utilized not only in the ocean but also in various fields of land and atmosphere.

• Korean Journal of Ichthyology
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• v.33 no.1
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• pp.31-36
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• 2021

In order to understand the age and growth characteristics of Pacific anchovy, Engraulis japonicus, the 506 otoliths of individuals collected in the southern waters of Korea in 2004 were analyzed. Monthly age of anchovies was estimated based on the age determined through the year rings and their collection date. The growth parameters obtained using the monthly folk lengths were a theoretical maximum body length of 132.9 mm, a growth coefficient of 0.1079/month and a theoretical age of 0.0262 month when the fork length is zero. The growth equation of von Bertalanffy presented by the growth parameters was L_t=132.9(1-e^{-0.1079(t-1.0262)}). The estimation of growth parameters based on the monthly age established through year ring and collection date was deemed appropriate for understanding the growth characteristics of anchovies.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.54 no.4
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• pp.324-332
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• 2018

We conducted a questionnaire survey to analyze the current status of the coastal composite fisheries, as well as the improvement point in designing a new type coastal composite fishing boat suitable for Korean fishing environments from April to August 2017. The questionnaire composed of 20 questions about the features of the coastal composite fishing boat and fishing work. The survey sites were selected to cover all parts of the country by considering the geographical position. The significance testing for the response results was accessed by ${\chi}^2$ test and ANOVA. The results revealed that more than half (59.1%) of the fishermen operated one day per voyage and operating alone topped with 22.5% in the number of crews, followed by 2 persons (20.3%) and 5 persons (22.1%). The navigation devices had a high rate of installation and GPS plotter ranked first in the devices. In addition, fish finder ranked first in fishing equipment, followed by net hauler. The most inconvenient work that they felt during the fishing operation was fish handing at 49.8% and other general fishing works like setting and hauling line, deck cleaning accounted for about 25%. The hardest work was the accident by ropes wrapped around propeller and the engine trouble came in second. The most inconvenient facilities to the present design of fishing boat was wheelhouse (76.7%), followed by fish hold (38.5%), and deck (35.1%). Furthermore, inconvenient points related to the movement of fishing gear, noise and vibration of engine, slippery deck and small fish hold exceeded 50%.