• Korean Journal of Fisheries and Aquatic Sciences
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• v.9 no.3
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• pp.155-162
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• 1976

Forty one samples from thirty three species of algae (19 from 15 species of Rhodophyceae, 18 from 14 species of Phaeophyceae, 3 from 3 species of Chlorophyceae, and 1 of marine Phanerogams) collected from several locations on the east, west and south coast of Korea, were analyzed for their contents of crude protein, fat, cellulose, ash, nitrogen free extract, amino nitrogen, and total amino acids. For the examination of extractability of algal protein with water, 4 species of algae, Sargassum thunberggi, Grateloupia filicina, Phyllospadix japonica, and Sargassum confusum, were analyzed. And the effect of some precipitation treatments for isolation of algal protein was also tested. As a matter of fact, Rhodophyceae showed high content in crude protein and low in crude fat while the case was opposite for Phaeophyceae and Chlorophyceae. Refering to the content of crude protein and total amino acids, the recommendable algae for protein sources were Sargassum thunbergii, Acrosorium flabellata, Phacelocarpus japonicus, Laurencia okamurai, Laurencia intermedia, Grateloupia filicina, Chondrus ocellatus, Gloiopeltis furcata, Gigartina tenella, Dictyota dichotoma, and Scytosiphon lomentaria. Methanol treatment appeared most effective in precipitation isolation of protein from water extracts whereas pH control method did not so beneficial. The precipitation rate of protein was particularity higher in the extract of Sargassum confusum ana the lowest was makted from the extract of Sargassum thunbergii.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.7
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• pp.1041-1051
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• 2005

In order to assure the safety of the seaweeds, we measured the contents of the trace metals in the seaweeds harvested from Korean coastal area. We collected 620 marine algal samples from fourteen areas, and then analyzed the trace metals such as Hg, Cd, Cr, Cu, Mn, Ni, Pb and Zn. The contents of Hg, Cd, Ni and Mn were higher in the seaweeds collected from Chungnam Taean area. The contents of Cr and Cu were higher in the seaweeds collected from Yeongdeok and Tongyeong area, respectively. And Pb and Zn were highly detected from the seaweeds of Ulsan area. The mean levels of trace metals were high in the order of Zn $(48.02\pm41.20{\mu}g/g)\;>\;Mn (34.63\pm38.95{\mu}g/g)\;>\;Cu(6.29\pm6.52{\mu}g/g)\;>\;Ni(2.17\pm4.00{\mu}g/g)\; >\;Cr(1.61\pm2.35{\mu}g/g)\;>\;Pb(1.28\pm2.37{\mu}g/g)\;>\; Cd(0.67\pm0.75{\mu}g/g)\;>\;Hg(0.02\pm0.02{\mu}g/g)$. Zn was consistently most abundant metal in all samples, followed by Mn and Cu, which are very important for human health. There were higher contents of Hg and Cd in brown algae, the contents of Cr, Cu, Mn, Ni and Pb in green algae, the content of Zn in red algae among them. Additionally, significant linear correlations were observed between a total 28 different pairs of metals, of them, the correlation factor between Cr and Ni showed the highest (r=0.374, p<0.001). The trace metal contents of seaweeds varied with habitats and kinds of samples, nevertheless they showed very safe level in edible seaweeds tested. Scytosiphon lomentaria, which has been known as a little use of food, have shown a clear selectivity for Cr and Pb. Among non-edible seaweeds, Sargassum thunbergii for both Cd and Mn, Lomentaria hakodatensis for Ni and Grateloupia prolongata for Zn have shown a clear selectivity, respectively. Therefore, these seaweeds could be useful as bioindicator for each trace metal pollution.

• Journal of the Korean Society of Food Science and Nutrition
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• v.13 no.3
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• pp.307-312
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• 1984

The dried pure shells deprived of soft tissues were subjected to analysis of chitin-protein complexes from 5 species of marine crustaceans, including 2 species of crabs and 3 species of shrimps. The protein fractions were obtained from chitin-protein complexes under the varying conditions of extractions and the crude chitin was prepared from the shells by the sulfurous acid process. The crude chitin was purified through the extraction with several organic solvents such as dimethyl-acetamide, N-methylpyrrolidone. The purified chitin was also examined using the phase contrast microscope. Total protein contents of the shells were diverse, showing 9.6% for Portunus trituberculatus, 3.1%, Charybdis bimaculata, 9.4%, Penaeus japonicus, 10.9%, Metapenaeus intermedius and 5.8%, Squilla oratoria. Covalently bound protein varied with species from 2.1% for Charybdis bimaculata to 9.9% for Metapenaeus intermedius. The puified chitin contents of the shells were shown to 21.1% for Portunus tritube rculatus, 6.2%, Charybdis bimaculata, 20.2%, Penaeus japonicus, 27.1%, Metapenaeus intermedius and 25.5%, Squilla oratoria. Exceptionally low analytical value obtained with Charybdis bimaculata are supposed to be due to the very young subjects. The ratios of chitin to covalently bound protein in the shells were various such as 2.7 to 1 for Portunus trituberculatus, Penaeus japonicus and Metapenaeus intermedius, 3.1 to 1, Charybdis bimaculata and 6.1 to 1, Squilla oratoria. The microscope finding of the purified chitin showed the filamentous form in all the specimen.

• Journal of the Korean Geophysical Society
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• v.2 no.1
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• pp.27-38
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• 1999

The errors between track segments or at the cross-over points of shipborne gravity were successfully reduced by applying a cross-over error adjustment technique using satellite gravity. The integration of shipborne and satellite altimeter-implied free-air gravity anomalies after the cross-over error adjustment resulted in a high resolution gravity map which contains both short and long wavelength components. The successful adjustment of the cross-over errors in the shipborne gravity using the satellite gravity suggests that the shipborne gravity can be combined with the satellite anomalies characterized by a stable and long wavelength component. The resulting free-air anomaly map is evenly harmonized with both short and long wavelength anomalies. Thus the corrected anomaly map can be better used for the geological interpretation. Free-air anomalies with more than 140 mGal in total variations generally correspond to the seafloor topographic changes in their regional patterns. A series of gravity highs are aligned from the Korea Plateau to the Oki Island, which are interpreted to be caused by seamounts or volcanic topographies. The gravity minima along the western and southern shelf edge are associated not only with the local basement morphology and thick sediment fill at the continental margin, but also possibly with the crustal edge effect known for passive continental margins. Series of NE-trending linear anomalies are possibly caused by a swarm of volcanic intrusions followed the initial opening of the Ulleung Basin. The linear high anomalies in the Ulleung Plateau are terminated by the straightly NNW-trending anomalies with a sharp gradient in its western boundary which indicates a fault-line scarp. The opposite side adjoined with the fault-line scarp shows no correlation with the fault-line scarp in geometry indicating that the block might be horizontally slided from the north. A gravity high in contrast to the deepening in seafloor toward the northeastern central Ulleung Basin is probably responsible for the thin crust and shallow seated mantle. The gravity minima along the western and southern shelf edge are associated not only with the local basement morphology and thick sediment fill at the continental margin, but also possibly with the crustal edge effect known for passive continental margins. Series of NE-trending linear anomalies are possibly caused by a swarm of volcanic intrusions followed the initial opening of the Ulleung Basin. The linear high anomalies in the Ulleung Plateau are terminated by the straightly NNW-trending anomalies with a sharp gradient in its western boundary which indicates a fault-line scarp. The opposite side adjoined with the fault-line scarp shows no correlation with the fault-line scarp in geometry indicating that the block might be horizontally slided from the north. A gravity high in contrast to the deepening in seafloor toward the northeastern central Ulleung Basin is probably suggestive of a thin crust and shallow seated mantle.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.35 no.6
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• pp.595-600
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• 2002

Comparison of blood properties in juvenile black seabream (Acanthopans schlegeli) between transfer from seawater to freshwater (sFW) and transfer from freshwater to seawater (fSW) were investigated for 60 days. Plasma cortisol levels in sFW were significantly increased from 34.2 $\pm$ 28.6 ng/mL at the beginning to 365.6 $\pm$ 136.0 ng/mL at 3 hours, and decreased to the beginning level at 24 hours. However, in fSW, no significant differences in the cortisol levels were recognized throughout experimental period. No significant difference was found in the glucose levels between sFW and fSW. The transfer from seawater to freshwater of juvenile black seabream resulted in reduced $Na^{+}\;and\; Cl^{-}$ concentrations for 24 hours (decreasing from 165.3 $\pm$ 2.5, 146.0$\pm$ 2.2 to 118.3 $\pm$ 12.3, 78.0$\pm$ 7.0 mEq/L, respectively), but these were completely recovered the beginning levels at 30 days. Total protein and AST showed no significant differences between the two rearing conditions, while ALT was markedly elevated at 3 hour in sFW and at 24 hours in fSW. Ht in sFW was increased from 18.5 $\pm$ $0.6\%$ at the beginning to 25.3 $\pm$ $4.0\%$ at 12 hours, and was decreased to the beginning level at 24 hours. Ht, RBC and Hb in fSW were also significantly higher at 12 hours, but recovered to their initial levels at 24 hours. All fish were dead until 50 days in sFW while survival rate in fSW was $85\%$ at the end of experiment.

• Economic and Environmental Geology
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• v.56 no.1
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• pp.55-63
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• 2023

Variations in geochemical and mineralogical properties of the ferromanganese(Fe-Mn) crust reflect environmental changes. In the present study, geochemical and mineralogical analyses, including micro X-ray fluorescence and X-ray diffraction, were utilized to reconstruct the paleo-ocean environment of western Pacific Magellan seamount cluster. Samples of the Fe-Mn crust were collected using an epibenthic sledge from the open seamount XX (151° 51.12' 7.2" E and 16° 8.16' 9.6" N, 1557 meters below sea level) in the Western Pacific Magellan Seamount. According to the structure and phosphating status, the Fe-Mn crust of the OSM-XX can be divided into the following: phosphatizated (L4-L5), massive non-phosphatizated (L3), and porous non-phosphatizated (L1-L2) portions. All ferromanganese layers contain vernadite, and owing to the presence of carbonate fluorapatite (CFA), the phosphatizated portion (L4-L5) is rich in Ca and P. The massive non-phosphatizated section (L3) contains high Mn, Ni, and Co, whereas the porous non-phosphatizated portion (L1-L2), which comprises detrital quartz and feldspar, is rich in Fe. Variations in properties of the Fe-Mn crust from the OSM-XX reflect changes in the nearby marine environment. The formation of this crust started at approximately 51.87 Ma, and precipitation of the CFA during the global phosphatization event that occurred at approximately 36-32 Ma highlights an elevated sea level and low temperature during the associated period. The high Mn, Ni, and Co concentrations and elevated Mn/Fe ratios of samples from the massive phosphatizated portion indicate that the oxygen minimum zone (OMZ) was enhanced, and reducing conditions prevailed during the crust formation. The high Fe and low Mn/Fe ratios in the porous portion indicate a weak OMZ and dominantly oxidizing conditions. These data reflect environmental changes following the end of the Mi-1 glacial period in the Miocene-Oligocene boundary. Subsequently, Mn/Fe and Co/Mn ratios increased slightly in the outermost part of Fe-Mn crust because of the enhanced bottom current and OMZ associated with the continued cooling from approximately 9 Ma. However, the reduced carbonate dissolution rate in the Pacific Ocean from approximately 6 Ma decreased the growth rate of the Fe-Mn crust.

• Korean Journal of Environmental Biology
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• v.41 no.4
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• pp.637-656
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• 2023

River estuaries are dynamic and productive ecosystems with high regional biodiversity. Environmental DNA (eDNA) has become a useful approach to assessing biodiversity in aquatic ecosystems. This study was conducted to investigate fish community characteristics and species diversity in two river estuary ecosystems, the Taehwa River and Changwon Stream. We further compared conventional and eDNA metabarcoding analyses of the fish communities. The conventional survey was performed in May, July, and October 2022, while the eDNA analysis was conducted only in May. We observed various fish species with different life histories, including carp, goby, and marine fish. We also found that migratory fish, such as dace Tribolodon hakonensis, sweetfish Plecoglossus altivelis, and eel Auguilla japonica, occurred in the Taehwa River, suggesting high river connectivity. Marine fish species were predominant in the Changwon Stream, as this river is located close to the sea. The diversity indices showed that the Taehwa River generally had higher species richness, evenness, and diversity values than the Changwon Stream. A total of 9-19 species were detected in the conventional survey for the three sites, whereas 11-18 species were found from eDNA analysis. The findings indicate that the sensitivity of eDNA was similar to or higher than that of the conventional method. Our study findings suggest the efficiency and efficacy of eDNA-based fish community monitoring, although with some shortcomings in applying the genetic marker to Korean fish, including no clear-cut distinction for Korean endemic species and/or genetically closely related species groups.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.2
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• pp.270-284
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• 1997

Effects of dietary carotenoids were investigated on the metaboβsm and body pigmentation of rainbow trout(Salmo gairdneri), masu salmon(Oncorhynchus macrostomos), eel(Anguilla japonica), rock fish(Sebastes inermis) and black rock fish(Sebastes schlegeli). Three weeks later after depletion, these fishes were fed diet supplemented with ${\beta}-carotene$, lutein, canthaxanthin', astaxanthin or ${\beta}-apo-8'-carotenal$ for 4 to 5 weeks, respectively. Carotenoids distributed to and changed in integument were analyzed. In the integument of rainbow trout. zeaxanthin, ${\beta}-carotene$ and canthaxanthin were found to be the major carotenoids, while lutein, isocryptoxanthin and salmoxanthin were the minor carotenoids. In the integument of masu salmon, zeaxanthin was found to be the major carotenoids, while triol, lutein, tunaxanthin, ${\beta}-carotene$, ${\beta}-cryptoxanthin$ and canthaxanthin were the minor carotenoids. In the integument of eel, ${\beta}-carotene$ was found to be the major carotenoids, while lutein, zeaxanthin and ${\beta}-cryptoxanthin$ were the minor carotenoids. In the integument of rock fish, zeaxanthin, ${\beta}-carotene$, tunaxanthin$(A{\sim}C)$ and lutein were found to be the major carotenoids, while ${\beta}-cryptoxanthin$, ${\alpha}-cryptoxanthin$ and astaxanthin were the minor carotenoids. Likely in the integument of black rock fish, ${\beta}-carotene$, astaxanthin and zeaxanthin were found to be the major carotenoids, whereas ${\alpha}-cryptoxanthin$, ${\beta}-cryptoxanthin$, lutein and canthaxanthin were the minor contributor. The efficacy of body pigmentation by the accumulation of carotenoids in the integument of rainbow trout and masu salmon were the most effectively shown in the canthaxanthin group and of eel, rock fish and black rock fish were the most effectively shown in the lutein group. Based on these results in the integument of each fish, dietary carotenoids were presumably biotransformed via oxidative and reductive pathways. In the rainbow trout, ${\beta}-carotene$ was oxidized to astaxanthin via successively isocryptoxanthin, echinenone and canthaxanthin. Lutein was oxidized to canthaxanthin. Canthaxanthin was reduced to ${\beta}-carotene$ via isozeaxanthin, and astaxanthin was reduced to zeaxanthin via triol. In the masu salmon, ${\beta}-carotene$ was oxidized to zeaxanthin. Lutein was reduced to zeaxanthin via tunaxanthin. Canthaxanthin was reduced to zeaxanthin via ${\beta}-carotene$. and astaxanthin was reduced to zeaxanthin via triol. In the eel, ${\beta}-carotene$ and lutein were directly deposited but canthaxanthin was reduced to ${\beta}-carotene$, and cholesterol lowering effect by Meju supplementation might be resulted from the modulation of fecal axanthin, astaxanthin and ${\beta}-apo-8'-carotenal$ were oxidized and reduced to tunaxanthin via zeaxanthin. In the black roch fish, ${\beta}-carotene$ was oxidized to ${\beta}-cryptoxanthin$. Lutein was reduced to ${\beta}-carotene$ via ${\alpha}-cryptoxanthin$. Canthaxanthin was reduced to ${\alpha}-cryptoxanthin$ via successively ${\beta}-cryptoxanthin$ and zeaxanthin. Astaxanthin converted to tunaxanthin via isocryptoxanthin and zeaxanthin, and ${\beta}-apo-8'-carotenal$ was reduced to ${\alpha}-cryptoxanthin$ via ${\beta}-cryptoxanthin$ and zeaxanthin.

• Journal of the Korean Society of Food Science and Nutrition
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• v.12 no.4
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• pp.407-419
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• 1983

In this study, the lipid components of three species of shellfish included oyster(Crassostrea gigas), top shell(Turbo cornutus) representing salt water shellfish and corb shell(Corbicula fluminea producta) representing flesh water shellfish were analysed and nutriontional significances were discussed. Analysed the total lipid composition, and the fatty acid and sterol composition of total lipid were determined. The lipid was fractionated into three lipid classes neutral, glyco and phospholipid by column chromatography. The fatty acid composition of each lipid class and sterols were determined by gas liquid chromatography. The lipid components of total lipid and neutral lipid were estimated by thin layer chromatography and TLC scanner. The results were as follows: Total lipid contents of shellfish were 1.8% in oyster, 0.4% in top shell and 4.0% in corb shell. The contents of total fatty acid in total lipid were 80.7, 71.2 and 73.2%; and the contents of unsaponifiable matters were 15.4, 18.1 and 23.1% respectively. Total lipids were mainly composed of triglycerides, polar lipid-pigments and sterols as major component, and hydrocarbon-esterified sterols were determined in each sample. The major fatty acids in total lipid were palmitic(37.0%), eicosapentaenoic(13.5%) and linoleic acid(11.2%) in oyster, Octadecatetraenoic(15.8%), palmitic(11.2%), oleic(8.6%) and linoleic acid(8.1%) in top shell, but palmitic(34.0%), linoleic(12.3%) and paimitoleic acid(9.8%) in corb shell. Particularly, the contents of eicosapentaenoic acid of oyster and top shell were higher than those of corb shell. Sterol composition from three species of shellfish were mainly consisted of cholesterol (42.7~64.0%), brassicasterol(15.6~24.7%) and 24-methylenecholesterol (4.7~21.9%). But sitosterol (5.3%) was detected only in oyster and 22-dehydrocholesterol(12.9%) was only in top shell. The contents of fractionated neutral lipid was commonly higher than that of polar lipid in each sample. Glycolipid and phospholipid in polar lipid showed similar in quantity. The neutral lipids were composed of triglycerides(33.0~36.7%), free sterols(25.7~31.2%), esterified sterol(12.4~23.7%) and free fatty acids(5.1~11.7%). The contents of triglycerides and free sterols were higher than those of free fatty acids and esterified sterols. The major fatty acids in neutral lipid were palmitic(28.4~26.4%) eicosapentaenoic(18.6~21.9%) and linoleic acid(9.0~5.4%) in oyster and corb shell but octadecatetraenoic(14.5%), eicosapentaenoic (13.5%) and palmitic acid(12.3%) in top shell. The major fatty acids in glycolipid were eicosenoic(10.2%), palmitic(12.1%) and linolenic acid (10.2%) in oyster, Eicosenoic(26.0%), octadecatetraenoic(14.6.%) and eicosadienoic acid(12.9%) in top shell. But eicosadienoic(21.4%) stearic(14.6%), octadecatetraenoic(8.5%) and eicosenoic acid(8.5%) in corb shell. The major fatty acids in phospholipid were myristic(16.0%), stearic(10.6%), eicosenoic(10.5%) and palmitic acid(10.3%) in oyster, Oleic(22.2%), stearic(20.7%) and linolenic acid (11.8%) in top shell but eicosapentaenoic(25.1%), myristic(8.7%) and arachidonic acid(8.3%) in corb shell.