East Sea Research Institute

Uljin, South Korea

East Sea Research Institute

Uljin, South Korea

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Oh S.-Y.,Tong Yeong Marine Living Resources Research and Conservation Center | Oh S.-Y.,Korean University of Science and Technology | Kim C.-K.,Marine Ecosystem Research Division | Jang Y.-S.,East Sea Research Institute | And 2 more authors.
Ocean and Polar Research | Year: 2014

The effect of salinity on the survival, oxygen consumption and blood physiology of Korean rockfish Sebastes schlegelii (body weight 97.4 ± 1.7 g, mean ± SD) was investigated at nine different salinities of 33.4 (control), 33.1, 32.8, 32.2, 31.0, 28.7, 23.9, 14.5 and 3.8 psu, respectively. Survival and blood physiology were measured at each salinity in two separate trials of 96 and 24 hr duration, respectively. Oxygen consumption rate (OCR) was determined at stepwise salinity exposure (33.4→33.1→ 32.8→32.2→31.0→28.7→23.9→14.5→3.8 psu) with an interval of 24 hr for each salinity. No death of fishes were observed in the range of 33.4 to 14.5 psu, but the survival rate was reduced to 26.7% at 3.8 psu after 96 hr. The OCRs were not significantly different in the range 33.4 to 28.7 psu (p > 0.05), but significantly increased until 14.5 psu and then drastically decreased at 3.8 psu compared to the control (p < 0.05). The concentrations of plasma Na+ and Cl- were significantly lower in fish exposed at 3.8 psu compared to the control (p < 0.05). The results of this study provide evidence that S. schlegelii exposed to concentrations below 23.9 psu show significant physiological responses to tolerate salinity changes under the experimental conditions we established.


Kang H.-S.,Jeju National University | Hong H.-K.,Jeju National University | Yang H.-S.,East Sea Research Institute | Park K.-I.,Kunsan National University | And 3 more authors.
Ocean and Polar Research | Year: 2015

Spatial variation in the reproductive effort of Manila clam Ruditapes philippinarum is often closely associated with variation in the seawater temperature and food availability, which determines gonad maturity and the quantity of gamates produced during spawning. Previous studies also have reported that severe infection by the protozoan parasite Perkinsus olseni exerts a negative impact on clam reproduction, retarding gonad maturation or decreasing the reproductive effort. In the present study, we investigated impacts of P. olseni infection on the reproductive condition of Manila clam during a spawning season. Histology revealed that 54% of female clams in Wando off the south coast were in spawning, while only 10% of the female from Gomso and 0% of the female from Seonjaedo in Gyeonggi bay off the west coast were engaged in spawning at the end of May in 2004. Ray’s fluid thioglycollate media (RFTM) assay was applied to assess P. olseni infection and indicated that the infection intensity in Wando (3,608,000 ± 258,000 cells/g wet tissue) was significantly higher than the levels in Gomso (1,305,000 ± 106,000 cells/g wet tissue) and Seonjaedo (1,083,000 ± 137,000 cells/g wet tissue, p < 0.001). The size of the ripe female follicle determined from histology was significantly smaller in Wando (0.032 mm 2) compared to the sizes in Gomso (0.059 mm 2) and Seonjaedo (0.052 mm2, p < 0.05). Accordingly, the number of ripe eggs in the follicle was significantly fewer among clams in Wando (14) compared to the numbers determined in Gomso (23) and Seonjaedo (22). The absolute quantity of egg in ripe clams from Wando (31.01 mg) was also significantly smaller than Seonjaedo (61.79 mg) and Gomso (133.3 mg). Quantity of total protein, carbohydrate, and lipid in the tissue in the Wando samples was significantly smaller than the quantities determined in Gomso and Seonjaedo (p < 0.001). The observed poor reproductive condition and proximate tissue composition of the females in Wando were, in part, explained by the extremely high level of the parasites, sapping the ability to store energy in the host tissues, which is used in tissue growth and the egg production. © 2015, Korea Ocean Research and Development Institute. All rights reserved.


Hong G.H.,Ocean Circulation and Climate Research Division | Yang D.B.,Special Marine Areas Management Center | Lee H.-M.,Special Marine Areas Management Center | Yang S.R.,Gwangju University | And 7 more authors.
Ocean Science Journal | Year: 2012

Korean Geostationary Ocean Color Imager (GOCI) and Moderate Resolution Imaging Spectroradiometer (MODIS) Aqua observations of the variation in ocean color at the sea surface were utilized to monitor the impact of nutrient-rich sewage sludge disposal in the oligotrophic area of the Yellow Sea. MODIS revealed that algal blooms persisted in the spring annually at the dump site in the Yellow Sea since year 2000 to the present. A number of implications of using products of the satellite ocean color imagers were exploited here based on the measurements in the Yellow Sea. GOCI observes almost every hour during the daylight period, every day since June 2011. Therefore, GOCI provides a powerful tool to monitor waste disposal at sea in real time. Tracking of disposal activity from a large tanker was possible hour by hour from the GOCI timeseries images compared to MODIS. Smaller changes in the color of the ocean surface can be easily observed, as GOCI resolves images at smaller scales in space and time in comparison to polar orbiting satellites, e. g., MODIS. GOCI may be widely used to monitor various marine activities in the sea, including waste disposal activity from ships. © 2012 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.


Yang H.-S.,East Sea Research Institute | Hong H.-K.,Jeju National University | Donaghy L.,Jeju National University | Noh C.-H.,East Sea Research Institute | And 3 more authors.
Ocean Science Journal | Year: 2015

Mytilus coruscus is a cold water mussel commonly occurring on shallow subtidal rocky substrata along the east coast of Korea. Despite its abundance, there have only been a few studies conducted reporting on its biology and ecology. In this study, we investigated the immune-related activities of hemocytes of M. coruscus using light microscopy and flow cytometry. Based on the morphology and cellular activities, 3 types of hemocytes were identified, as granulocytes, hyalinocytes, and blast-like cells. Granulocytes, containing numerous intra-cytoplasmic granules, were intermediate-size (11.8μm) and the most abundant cells (70.2%), while hyalinocytes were the largest cells (16.0μm), with no or few granules in their cytoplasm. The granulocytes exhibited higher lysosomal content, phagocytosis activity and oxidative capacities than the hyalinocytes. In contrast, the blast-like cells were the smallest cells (6.4μm) and displayed a lack of phagocytosis and oxidative capacities. In M. coruscus, the granulocytes appear as the major cell type involved in cellular defense, whereas the blast-like cells may not be directly involved in cell-mediated immune response. © 2015, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.


PubMed | Daegu Haany University, East Sea Research Institute, KIOST, Gyeongbuk Institute for Marine Bio Industry and Korea Institute of Oriental Medicine
Type: | Journal: Evidence-based complementary and alternative medicine : eCAM | Year: 2015

We evaluated the preventive effects of four types of seawater collected in Republic of Korea on hairless mice with 2,4-dinitrochlorobenzene- (DNCB-) induced allergic/atopic dermatitis (AD). The anti-inflammatory effects were evaluated by measuring tumor necrosis factor- (TNF-) and interleukins (ILs). Glutathione (GSH), malondialdehyde (MDA), superoxide anion, and inducible nitric oxide synthase (iNOS) were measured to evaluate the antioxidant effects. Caspase-3 and poly (ADP-ribose) polymerase (PARP) were observed to measure the antiapoptotic effects; matrix metalloproteinase- (MMP-) 9 levels were also evaluated. Mice with AD had markedly higher clinical skin severity scores and scratching behaviors; higher TNF- and ILs (1, 10, 4, 5, and 13) levels; higher MDA, superoxide anion, caspase-3, PARP, and MMP-9 levels; and greater iNOS activity. However, the severity of AD was significantly decreased by bathing in seawaters, but it did not influence the dermal collagen depositions and skin tissue antioxidant defense systems. These results suggest that bathing in all four seawaters has protective effects against DNCB-induced AD through their favorable systemic and local immunomodulatory effects, active cytoprotective antiapoptotic effects, inhibitory effects of MMP activity and anti-inflammatory and antioxidative effects.


Min W.,East Sea Research Institute | Kim D.,East Sea Research Institute | Decraemer W.,Royal Belgian Institute Of Natural Sciences | Decraemer W.,Ghent University | Rho H.S.,East Sea Research Institute
Ocean Science Journal | Year: 2016

A new species of free-living marine draconematid nematode, Dracograllus trukensis sp. nov., is described based on the specimens collected from the sediments of a intertidal seagrass bed from Chuuk Islands, Micronesia. Dracograllus trukensis sp. nov. differs from other species of the genus by the combination of the following characteristics: the presence of numerous minute spiny ornamented body cuticular annules in both sexes, eight cephalic adhesion tubes inserted on the head capsule in both sexes, the presence of stiff posteriorly directed setae anterior to posterior adhesion tubes in both sexes, the shape (large, elongated, open loop-shaped in male and large, elongated, closed loop-shaped in female) and position (longer ventral arm extending to the first body annule in male) of amphideal fovea, shorter spicule length (34–42 μm), the presence of sexual dimorphism in shape and length of the non-annulated tail terminus, and number of posterior sublateral adhesion tubes (10 in male and 13–15 in female) and posterior subventral adhesion tubes (8–10 in male and 9–11 in female). A comparative table on the biogeographical and ecological characteristics of the species of Dracograllus is presented. This is the first taxonomic report on the genus Dracograllus from Chuuk Islands, Micronesia, central western Pacific Ocean. © 2016, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.


Rho H.S.,Royal Belgian Institute Of Natural Sciences | Rho H.S.,East Sea Research Institute | Min W.G.,East Sea Research Institute | Decraemer W.,Royal Belgian Institute Of Natural Sciences | And 2 more authors.
Marine Biology Research | Year: 2010

A draconematid nematode Prochaetosoma dokdoense sp. nov., first discovered in December 2006 at a subtidal zone of Dokdo, Korea, the northwest Pacific Ocean, is described. This new species was obtained from coarse detritus and shell gravels. Prochaetosoma dokdoense sp. nov. differs from all the species hitherto described by the following combination of characteristics: longer slender body (910 1175 mm), elongate loop-shaped amphidial fovea in male (distal end of ventral arm slightly curved anteriorly), eight cephalic adhesion tubes in both sexes positioned just anterior to swollen pharyngeal region, number of posterior sublateral adhesion tubes (6 in male and 6 10 in female) and posterior subventral adhesion tubes (7 8 in male and 8 9 in female), longer spicule length (78 86 mm), long cylindro-conoid tail (114 131 mm in male and 116 131 mm in female) and higher ratio c? (6.5 7.5 in male and 7.4 9 in female). A table comparing the major differential diagnostic characteristics of the species of the genus Prochaetosoma Micoletzky, 1922 is presented. For a reliable understanding of the geographic distribution and species identification of the genus Prochaetosoma, a pictorial key showing the relative length of non-annulated tail terminus to total tail length in both sexes is included, together with a dichotomous species identification key based on adults and fourth-stage juvenile as far as known. This is the first record of the genus Prochaetosoma in the northwest Pacific Ocean. © 2010 Taylor & Francis.


Cho M.L.,East Sea Research Institute | Lee D.-J.,Gangneung - Wonju National University | Lee H.-S.,Global Bioresources Research Center | Lee Y.-J.,Global Bioresources Research Center | You S.G.,Gangneung - Wonju National University
Ocean Science Journal | Year: 2013

The nitric oxide inhibitory (NOI) and antioxidant (ABTS and DPPH radical scavenging effects with reducing power) activities of the ethanol (EtOH) extracts and solvent partitioned fractions from Scytosiphon lomentaria, Chorda filum, Agarum cribrosum, and Desmarestia viridis were investigated, and the correlation between biological activity and total phenolic (TP) and phlorotannin (TPT) content was determined by PCA analysis. The yield of EtOH extracts from four brown seaweeds ranged from 2.6 to 6.6% with the highest yield from D. viridis, and the predominant compounds in their solvent partitioned fractions had medium and/or less polarity. The TP and TPT content of the EtOH extracts were in the ranges of 25.0-44.1 mg GAE/g sample and 0.2-4.6 mg PG/g sample, respectively, which were mostly included in the organic solvent partitioned fractions. Strong NOI activity was observed in the EtOH extracts and their solvent partitioned fractions from D. viridis and C. filum. In addition, the EtOH extract and its solvent partitioned fractions of D. viridis exhibited little cytotoxicity to Raw 264.7 cells. The most potent ABTS and DPPH radical scavenging capacity was shown in the EtOH extracts and their solvent partitioned fractions from S. lomentaria and C. filum, and both also exhibited strong reducing ability. In the PCA analysis the content of TPT had a good correlation with DPPH (r = 0.62), ABTS (r = 0.69) and reducing power (r = 0.65), however, an unfair correlation was observed between the contents of TP and TPT and NOI, suggesting that the phlorotannins might be responsible for the DPPH and ABTS radical scavenging activities. © 2013 Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.


Cho M.,East Sea Research Institute | Yoon S.J.,East Sea Research Institute | Kim Y.-B.,East Sea Research Institute
Ocean and Polar Research | Year: 2013

The proximate composition, free amino acid composition and mineral contents from Undariopsis peterseniana were determined, and the antioxidant activities of ethanol (EtOH) and hot water extracts of U. peterseniana were investigated using DPPH (1,1-diphenyl-1-picrylhydrazyl), ABTS (2,2'- azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)) radical scavenging effects and reducing power. The contents of moisture, ash, protein, lipid and carbohydrate were 12.5%, 23.1%, 9.7%, 0.2% and 54.5%, respectively, and alginic acid content was 12.3%. The major free amino acid contents were alanine, phenylalanine, aminoethanol, valine, glutamic acid and phosphoserine. Ca (1589.1 mg) was the largest mineral followed by Na (344.6 mg), Mg (74.3 mg), Zn (10.2 mg) and Fe (1.5 mg). The total phenolic contents of EtOH and hot water extracts were exhibited at 15.7 and 4.3 mg GAE/g sample, respectively. The antioxidant activity of EtOH extract exhibited strong ABTS and DPPH radical scavenging activities with reducing power, and hot water extract also demonstrated strong ABTS radical scavenging effects. Therefore, the results of this study suggest that U. peterseniana contained an abundance of naturally occurring nutrients (free amino acids and minerals), and the strong antioxidant activities of EtOH and hot water extracts from U. peterseniana could be good sources of natural antioxidants for healthcare products.


Song K.-H.,Marine Chemistry and Geochemistry Research Center | Choi K.-Y.,East Sea Research Institute | Kim C.-J.,Marine Chemistry and Geochemistry Research Center | Kim Y.-I.,East Sea Research Institute | Chung C.-S.,Marine Chemistry and Geochemistry Research Center
Ocean Science Journal | Year: 2015

As with many countries, the Korea government has made a variety of efforts to meet the precautionary principle under the London Convention and Protocol acceded in 1994 and 2009. However, new strategies for the suitable marine dumping of waste materials have since been developed. In this study, the distribution and contamination of heavy metals including Al, Fe, Mn, Li, Co, Cr, Ni, Cu, Zn, As, Cd, Pb and Hg in bottom sediments were analyzed and compared to various criteria in order to evaluate the effectiveness of the management of the East Sea-Jung (ES-Jung) dumping site by the Korea government. The results indicate that the average metal concentrations were significantly lower than Effects Range Low (ERL) values, and generally similar to or lower than the Threshold Effect Levels (TEL) from the Sediment Quality Guidelinces (SQGs). According to analyses of various metal contamination indexes (Enrichment Factor: EF, Pollution Load Index: PLI and the Index of Geoaccumulation: Igeo), most areas were found to be uncontaminated by heavy metals with the exception of several moderately contaminated stations (ESJ 33, 54, 64 and ESJR 20). Heavy metal concentrations in areas grouped as G1, G2, DMDA, N-Ref and S-Ref which showed similar characteristics between 2007-2013 and 2014, were compared. Unexpectedly, most concentrations in the northern reference area (N-Ref) were much higher than those in the actual dumping areas (G1 and G2), may be due to the influences from nearby cities to the west of the ES-Jung site, rather than from the dumping site itself. Additionally, heavy metal concentrations in the dredged material dumping area (DMDA) were found to be low although they have slightly increased over time and those in the southern reference area (S-Ref) were found to have gradually decreased with year. The concentrations of most metals in the East Sea-Jung dumping site were similar to or less than those in the Earth’s crust and approximately the same as those in continental sediments. As a result, this site can be considered as uncontaminated or slightly contaminated. This implies that the efforts made by the Korea government to manage and govern the dumping site through various policies, including ‘the focal point system’, ‘the responsibility zones system’ and ‘the principle of pollution causing party liability’, have been successful. © 2015, Korea Ocean Research & Development Institute (KORDI) and the Korean Society of Oceanography (KSO) and Springer Science+Business Media Dordrecht.

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