• Journal of Marine Bioscience and Biotechnology
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• v.12 no.1
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• pp.11-19
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• 2020

This study aims to review the progress of biotechnological applications of sea cucumber and presents fundamental validation data on a range of methods and applications to determine the most promising fields for future exploitation and application. Sea cucumbers from different regions, subjected to numerous industrially applicable drying methods, were evaluated for their biochemical composition. The study highlights the nutritional excellence of Jeju red sea cucumber, particularly the high amino acid and fatty acid composition of its intestinal organs and the possibility of the industrial utilization of these organs. In addition, an efficient extraction method to extract collagen and chondroitin sulfate from red sea cucumber was established. The extracted collagen and chondroitin sulfate can be used as commercially valid biomaterials. Accordingly, the red sea cucumber was confirmed as a valuable source of raw food material of varied functionality and bioactivity. Upon conducting an analysis of patents thus far relating to the sea cucumber, it was found that the associated technology was limited to some parts of primary and secondary industries. Therefore, there is a clear need for the strategic development of technologies to produce specialized functional products from sea cucumber's raw materials, with a view to promote other related industries.

• Journal of Navigation and Port Research
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• v.37 no.3
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• pp.245-250
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• 2013

As maritime traffic increases and ships get bigger and faster, the risk of maritime accident increases. According to the recent reports on maritime accidents, more than 80% of the maritime accidents occur due to navigational mistakes and/or human errors. Even though many kinds of navigation systems based on new technology have been developed to reduce maritime accidents, we need to research the method for expressing and providing information. The efficient navigation system should be able to display information simply and intuitively to make decision quickly and accurately. In this paper, we proposed augmented reality based navigation system which can be utilized in bridge of the ships and described the services for navigational safety.

• Korean Journal of Environmental Biology
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• v.37 no.3
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• pp.389-395
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• 2019

In this study, we aimed to assess the toxicity of biocide present in antifouling paint on embryos of sea urchin, Mesocentrotus nudus. Three types of biocide (Sea-nine 211, Diuron, and Irgarol 1051) were selected for the exposure experiment. The EC₅₀ of Sea-nine, Diuron, and Irgarol on the fertilization rate of sea urchin were 32.8 ㎍ L^-1, 7,975 ㎍ L^-1 and 6,995 ㎍ L^-1, respectively. The EC₅₀ of Sea-nine, Diuron, and Irgarol on the development rate of sea urchin were 31.6 ㎍ L^-1, 3,044 ㎍ L^-1, and 2,267 ㎍ L^-1, respectively. The highest toxicity was observed in the presence of Sea-nine.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.3
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• pp.217-225
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• 2013

It is time to develop new renewable energy that could fundamentally replace fossil fuel, which has been increasingly needed due to environmental pollution and energy security. Korean marine bio-energy development project is planned to produce 50% of total bioenergy. This study attempts to measure the greenhouse gas emission reduction benefits of marine bio-energy development project through contingent valuation method. Single bounded dichotomous choice (SBDC) is applied with spike model. The results show that the average willingness to pay are estimated to be KRW 4,190 at SBDC, per household per year. If the result has been expanded to the region which is survey conducted, KRW 50.1 billion annually. These quantitative information can be usefully utilized in the cost benefit analysis to implement project and policy-making for the industrialization of marine bio-energy development project.

• Ocean and Polar Research
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• v.35 no.1
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• pp.27-37
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• 2013

The western coast of Anmyeondo is open toward the Yellow sea and the northern and southern coasts are sandy and have simple coastlines. In this study, we investigated the spatial distribution and community structure of the macrobenthos that inhabit the sandy shore of Anmyeondo. For the study, we chose 8 sites encompassing 44 stations. In total, we have recorded 62 species, and collected 747 inds./$m^2$ on average. Zonation pattern did not appear because the mean grain size and organic contents of the study sites were similar among the macrobenthos. Polychaetes were most frequently recorded, but amphipods appeared in higher mean density. Macrobenthic community is classified into 3 groups largely based on the density difference among the dominant species and the groups were not influenced by environmental factors. The aggregated distribution of macrobenthos did not show a clear regional spatial difference but exhibited classification pattern emphasizing the density difference of the dominant species. The sandy shores of Anmyeondo are relatively more influenced by waves compared to other regions and the sediment moves more due to strong winds, etc. at low tide. We presume that the movement of sediment resulted in a relatively even sedimentary environment and consequently weakened environmental variables that change with the tide level. We concluded that the macrobenthic community does not show the zonation pattern in the sandy shores of Anmyeondo due to such influences.

• Ocean and Polar Research
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• v.35 no.1
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• pp.15-26
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• 2013

The toxic, Harmful Algal Blooms (HABs) caused by the Cochlodinium polykrikoides have a serious impact on the coastal waters of Korea. In this study, the acoustic detection system was developed for rapid HABs detection, based on the acoustic backscattering properties of the C. polykrikoides. The developed system was mainly composed of a pulser-receiver board, a signal processor board, a control board, a network board, a power board, ultrasonic sensors (3.5 and 5.0 MHz), an environmental sensor, GPS, and a land-based control unit. To evaluate the performance of the system, a trail was done at a laboratory, and two in situ trials were conducted: (1) when there was no red tide, and (2) when there was red tide. In the laboratory evaluation, the system performed well in accordance with the number of C. polykrikoides in the received level. Second, under the condition when there was no red tide in the field, there was a good correlation between the acoustic data and sampling data. Finally, under the condition when there was red tide in the field, the system successfully worked at various densities in accordance with the number of C. polykrikoides, and the results corresponded with the sampling data and monitoring result of NFRDI (National Fisheries Research & Development Institute). From the laboratory and field evaluations, the developed acoustic detection system for early detecting HABs has demonstrated that it could be a significant system to monitor the occurrence of HABs in coastal regions.

• Ocean and Polar Research
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• v.39 no.1
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• pp.23-34
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• 2017

This study was carried out to investigate the spatial distributions of the macrobenthic communities in the Seomjin River estuary from May, 2015 to May, 2016. The number of species was 163, the mean density was $1,865ind.m^{-2}$, biomass was $204g{\cdot}wet\;m^{-2}$ during this study period. The highest number of species and density appeared among polychaetes whereas the most biomass was contributed by mollusks due to the presence of Corbicula japonica in every season. The study area was divided into 3 regions with similar benthic fauna responding to the gradient of the salinity. Praxillella praetermissa was the dominant species in regions of over 30 psu during all seasons. C. japonica and Hediste diadroma were dominant in the upper regions of the Seomjin River where the salinity was less than 10 psu. Heteromastus filiformis showed the broadest distributional range and dominated in all seasons except for the most upper stream at st. 7. From the result of the Bio-Env analysis, salinity was the most important environmental factor affecting the formation of macrobenthic communities in the study area, and salinity and TOC were the highest contributors to the macrobenthic communities. From the correlation analysis between major dominant species and environmental factors, C. japonica, Prionospio japonica and H. diadroma showed a negative correlation with salinity, while P. praetermissa and Scolectoma longifolia showed a positive correlation. H. filiformis was little affected by salinity but showed a positive correlation with TOC or silt content of sediment.

• Ocean and Polar Research
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• v.37 no.1
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• pp.37-47
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• 2015

The effects of low salinity (fertilization success and larval survival) on the limpet Cellana grata were studied at early stages of development using the marine bioassay technique. It was shown that, under normal conditions for development from fertilization to the post veliger stage, the salinity must be not less than 20.0~35.0 psu. However, the fertilization rate and larval survival of C. grata was obviously reduced at 5.0 psu and 10.0 psu, respectively. Mass mortality was estimated to occur at <20.0 psu (48-h $EC_{50}=19.54psu$) and the survival rate of normal veliger larvae decreased with experimental time during exposure. No observed effective concentration (NOEC) and lowest observed effect concentration (LOEC) of post veliger were estimated at 30.0 psu and 25.0 psu, respectively, during 48-h exposure. The tolerance limits of the test species to salinity revealed various concentration ranges of salinity, which may reflect the physiology and ecology of the initial development stages of C. grata. These results demonstrate that reduced salinity is detrimental to the reproductive success and larval survival of C. grata, and if salinity is lowered by natural or anthropogenic sources during spawning, this would lead to decreased reproductive success and larval settlement.

• Ocean and Polar Research
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• v.37 no.3
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• pp.189-200
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• 2015

Mesozooplankton biomass including total biomass and size-fractionated biomass and the abundance of major taxonomic groups of copepods were studied in the Northwestern Subtropical Pacific Warm Pool (NSPWP) and the Northern East China Sea (NECS) from 2006 to 2014. Mesozooplankton biomass ranged from 0.69 to $3.08mgC/m^3$ (mean $1.12mgC/m^3$) in the NSPWP and from 10.60 to $69.10mgC/m^3$ (mean $30.33mgC/m^3$) in the NECS with higher values in spring than fall. Percent composition in the biomass of each size group of mesozooplankton varied interannually both in the NSPWP and in the NECS. The smallest size group (0.2~0.5 mm) contributed the least to total biomass in both regions, but significantly higher in the NSPWP than in the NECS. The percent composition in abundance of copepod taxonomic groups (i.e. Calanoida, Cyclopoida, and Poecilostomatoida) also fluctuated interannually. Mean composition of calanoid copepods was higher in the NECS than in the NSPWP, but the opposite pattern was observed for poecilostomatoid copepods. Mesozooplankton biomass both in the NSPWP and in the NECS was negatively correlated with Oceanic $Ni{\tilde{n}}o$ Index (ONI), indicating declines in biomass during El $Ni{\tilde{n}}o$ periods and vice versa during Na $Ni{\tilde{n}}a$ period. The effect of El $Ni{\tilde{n}}o$ on variation of mesozooplankton biomass was more prominent in the NSPWP than in the NECS. These results suggest that mesozooplankton biomass both in the NSPWP and in the NECS responded to El $Ni{\tilde{n}}o$ events, although the biological process that explain the reduced mesozooplankton biomass might be different in both regions.

• Ocean and Polar Research
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• v.36 no.4
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• pp.437-445
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• 2014

A time-series sediment trap was operated at a water depth of 4950 m from July 2003 to May 2004 at KOMO station ($10^{\circ}30^{\prime}N$, $131^{\circ}20^{\prime}W$) in the northeastern equatorial Pacific, with the aim of understanding the temporal variation of planktonic foraminifera assemblages in response to the seasonal shift of Inter-Tropical Convergence Zone (ITCZ). A total of 22130 planktonic foraminifera specimens belonging to 30 species and 11 genera were identified, which shows a distinct seasonal variation with high values (125~288 specimens $m^{-2}day^{-1}$) in the winter to spring (December-May) and low values (16~23 specimens $m^{-2}day^{-1}$) in the fall (September-November). In addition, seasonal ecological differences of foraminifera assemblages are distinctly recognizable: omnivorous foraminifera occurred predominantly during the summer season, whereas herbivorous ones were dominant during the winter season. Such seasonal variations correspond to the seasonal shift of the ITCZ. Enhanced occurrence of herbivorous species during the winter-spring season seems a result of surface water mixing generated by the southward shift of the ITCZ. The increase in omnivorous species during the summer season may be due to the northward movement of the ITCZ caused by weakened wind speed, resulting in the intensification of water column stratification and nutrient-poor environment. A significant reduction of planktonic foraminifera specimens during the fall is attributed to heavy precipitation and reduction in light intensity.