• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.447-448
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• 2004

• Proceedings of the Korean Aquaculture Society Conference
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• 2004.05a
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• pp.449-450
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• 2004

• Ocean and Polar Research
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• v.41 no.2
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• pp.47-61
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• 2019

The Dokdo coast is known for its high biodiversity. However, few studies have examined the biodiversity and macrobenthic community on the subtidal soft-bottom. Therefore, we collected macrobenthos (> 1 mm) using a Smith-McIntyre grab ($0.1m^2$) at 15 stations along the Dokdo coast in September 2016. The sediments consisted of badly sorted (1.7) coarse sand with gravel and the mean sediment grain size was $-0.4{\phi}$. In total, 177 macrobenthic species were collected; their mean density was $1,566ind./m^2$. The number of species and density of macrobenthic fauna decreased significantly with the mean grain size. The dominant species were the amphipods Melita denticulata (16.5%) and Melita shimizui (5.5%), polychaete Salvatoria clavata (5.4%), bivalve Glycymeris aspersa (4.4%), and ophiuroid Ophionereis dubia (4.3%). The dominant macrobenthos species on the subtidal soft-bottom differed from the coastal areas of the East Sea, suggesting that the difference in the sediment grain size affected the macrobenthos. Cluster analysis was performed to divide the study area into four groups, and environmental factors which correlated with species composition and distribution in the study area were the combination of the four parameters of salinity, dissolved oxygen, total organic carbon and depth. A future seasonal investigation is needed to understand the species composition and characteristics of the Dokdo macrobenthos.

• Ocean and Polar Research
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• v.42 no.3
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• pp.195-210
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• 2020

The observed time series from the Korea Ocean Research Stations (KORS) in the Yellow and East China Seas (YECS) have various sources of noise, including bio-fouling on the underwater sensors, intermittent depletion of power, cable leakage, and interference between the sensors' signals. Besides these technical issues, intricate waves associated with background tidal currents tend to result in substantial oscillations in oceanic time series. Such technical and environmental issues require a regionally optimized automatic quality control (QC) procedure. Before the achievement of this ultimate goal, we examined the approach of the Ocean Observatories Initiative (OOI)'s standard QC to investigate whether this procedure is pertinent to the KORS. The OOI QC consists of three categorized tests of global/local range of data, temporal variation including spike and gradient, and sensor-related issues associated with its stuck and drift. These OOI QC algorithms have been applied to the water temperature time series from the Ieodo station, one of the KORS. Obvious outliers are flagged successfully by the global/local range checks and the spike check. Both stuck and drift checks barely detected sensor-related errors, owing to frequent sensor cleaning and maintenance. The gradient check, however, fails to flag the remained outliers that tend to stick together closely, as well as often tend to mark probably good data as wrong data, especially data characterized by considerable fluctuations near the thermocline. These results suggest that the gradient check might not be relevant to observations involving considerable natural fluctuations as well as technical issues. Our study highlights the necessity of a new algorithm such as a standard deviation-based outlier check using multiple moving windows to replace the gradient check and an additional algorithm of an inter-consistency check with a related variable to build a standard QC procedure for the KORS.

• Korean Journal of Ichthyology
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• v.33 no.2
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• pp.142-147
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• 2021

A single specimen (52.5 mm SL) of Neoclinus chihiroe, belonging to the family Chaenopsidae, was firstly collected from Dokdo, East Sea of Korea on 9 December 2020. This species was characterized by a black spot between the first and the second dorsal spines, and a black spot on upper part of opercular membrane. The species was morphologically similar to N. okazakii, but distinctly distinguished by pectoral fin base without a black dot. This study documents the first record of N. chihiroe in Korean waters and suggests the new Korean name 'Dong-hae-bi-neul-be-do-la-chi' for the species.

• Ocean and Polar Research
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• v.37 no.4
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• pp.369-383
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• 2015

The purpose of this study is to ascertain the demands for developing marine science technology to reduce fatalities caused by marine accidents. For this purpose, we analyzed the contents of about 77,000 news articles posted for a month after the tragedy of the Sewol (April 16~May 15) to identify keywords and then we used the Social Network Analysis (SNA) for each keyword. The findings of the analysis show that there are five networks and that each one reveals different aspects about technology development to prepare for marine accidents. Based on these findings, we categorized three kinds of demands for technology development from the perspective of marine science technology: provision of the information about the marine environment, development of equipment and technology to overcome extreme environments, and the establishment of a field support system.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.20 no.1
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• pp.29-35
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• 2015

Dissolved nutrients in seawater are recognized as an essential biogeochemical factor for detecting global environmental changes. The importance of nutrient reference material for seawater has been increased greatly for the comparison of nutrient data, measured in different time and space in global ocean by various researchers with different levels in nutrient analysis skill. In this study, we described the homogeneity and stability of nutrient reference material for seawater using natural seawater, collected at a station of Shihwa Lake, at a coastal station near Uljin (surface water), and at a station over the Ulleung Basin (surface water and 1500 m depth water) and sterilized. Based on the homogeneity data, the nutrient reference materials has similar homogeneity compared to other nutrient reference materials. During 3-13 month period, there was no unidirectional trend of increase or decrease in nutrient concentration of newly developed nutrient reference material for seawater. However, a sustained measurement is required to check stability for longer period.

• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.131-131
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• 2018

• Proceedings of KOSOMES biannual meeting
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• 2017.04a
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• pp.97-97
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• 2017

• Proceedings of KOSOMES biannual meeting
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• 2017.11a
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• pp.244-244
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• 2017