• Korean Journal of Ecology and Environment
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• v.39 no.1 s.115
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• pp.93-99
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• 2006

Primary productivity was determined by using $^{13}C$ tracer according to different cell size of phytoplank-ton through in situ incubation experiments in upper stream of the Lake Shihwa. The average concentration of chlorophyll a was 14 ${\mu}g\;L^{-1}$ demonstrating an eutrophic water. The ratio of POC/Chl-a was lower than 30, reflecting that the origin of organic matter might be mainly phytoplankton. The primary productivity was 93.9 mgC m^{-2}\;d^{-1}$ at St. 1, which was about 40-fold lower than the average value of the lake (3,972 mgC m^{-2}\;d^{-1}$) determined by Choi et al. (1997) before opening of gate but it was higher than the average primary productivity (3.98 mgC m^{-2}\;d^{-1}$) reported by KOWACO in 1993 before constructing dam. The fractionated size (20 ${\sim}$ 53 ${\mu}m$) of phytoplankton community account for 51% of total primary productivity, indicating the highest assimilation rate. This study suggest that $^{13}C$ tracer methodology should be applied as a useful approach for the water ecological research in the future.

• Journal of the Korean association of regional geographers
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• v.17 no.6
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• pp.649-665
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• 2011

Estuary of River Nakdong(in south-eastern coast of Korean Peninsula) is the most representative site of delta in Korea. This study is to elucidate morpho-structural background associated with the embayment area and sedimentation processes, having allowed development of the delta. In this area, Great morphological trait of the embayment area had been formulated by differential erosion exploiting regional fracture system(NNE-SSW, NNW-SSE, E-W,...) of tectonic origin. For this reason, outline of the embayment basin shows quadrangular plan, and ridges and dissected valleys of neighbouring mountains draw frequently morphological lineament pattern. At the last glacial age when delta deposit had not yet filled the actual embayment basin of the Nakdong, mechanical weathering(frost shattering) and mass-movement processes had provided detritus materials composed of blocks, boulders on bottom the basin. With the postglacial transgression in the Holocene, the basin had been submerged, then began to be filled with fluvio-marine deposits from Kimhae-Yangsan area toward actual estuarine zone, so that Nakdong delta have been formed. Analysis and synthesis of from hundreds of boring data of the delta area reveal that progression of delta formation have been accompanied with the development of barrier islands. If the barrier islands had grown as forming a plural row, then their intervals have posteriorly filled with another fluvio-marine deposits. Besides, it shows that delta deposits are essentially alluvial. However, at the periphery of the delta, intervention of fine marine deposits is frequently found.

• The Korean Journal of Petroleum Geology
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• v.6 no.1_2 s.7
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• pp.37-43
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• 1998

Chemical components of water, chemical and isotopic compositions of extractable gases were analyzed to characterize the properties of the natural gases which are dissolved in ground water in the Pohang area. Amount of total extracted gases ranges from 27 ml/l to 50.1 ml/l. Hydrocarbon gases are composed of methane ($27{\~}376,420 ppm$) and ethane ($19{\~}127 ppm$). Amount of total hydrocarbon gases is related to the lithology and geological factors around the reservoir. Quantity of hydrocarbon gases tends to increase in the Tertiary reservoirs and in the reservoirs where the Tertiary formations are thick enough. According to the relationship between hydrocarbon gases and total solids in the ground water, it is believed that the hydrocarbon gases were dissolved in the Tertiary formation water. Based on the methane content ($>99.9\%$) and isotopic composition (${\delta}C^{13};-73.1\%_{\circ}{\~}-43.22\%_{\circ}$), we interpret the gases to be of predominantly biogenic origin which were generated by the methanogenic bacterial processes under the low temperature and anoxic conditions.

• Food Engineering Progress
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• v.22 no.4
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• pp.337-343
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• 2018

Coffee is a commonly consumed beverage that contains anti-inflammatory compounds such as caffeine, chlorogenic acid, cafestol, trigonelline, and kahweol. Lactobacillus plantarum is a lactic acid bacterium most frequently used in the fermentation of food products of plant origin. L. plantarum is able to degrade some food phenolic compounds and provide high value-added compounds such as powerful antioxidants or food additives approved as flavouring agents. In this study, we investigated the anti-inflammatory effects of coffee extract fermented by L. plantarum on RAW264.7 macrophages. In lipopolysaccharide-stimulated RAW264.7 cells, these coffee extracts exhibited anti-inflammatory activities through the reduction of nitric oxide (NO) production and inducible NO synthase expression. Fermented coffee extracts significantly decreased the expression of inflammatory cytokines such as tumor necrosis factor ${\alpha}$, interleukin $1{\beta}$, interleukin 6, and interferon ${\gamma}$. Cyclooxygenase-2, which is one of the key biomarkers for inflammation, was significantly suppressed. These results might be helpful for understanding the anti-inflammatory mechanism of fermented coffee extract on immune cells and, moreover, suggest that fermented coffee extract may be a beneficial anti-inflammatory agent.

• Fisheries and Aquatic Sciences
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• v.27 no.4
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• pp.213-224
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• 2024

Betta rubra, classified as endangered fish species by the International Union for Conservation of Nature (IUCN), has been successfully bred and raised in captivity for two generations under laboratory conditions. This study aimed to provide comprehensive information on the captive breeding of B. rubra, focusing on various parameters crucial for ex-situ conservation and domestication. The research involved breeding trials, embryo and larvae observation, first feeding experiments, larva and fry rearing trials, and the evaluation of growth and reproduction in two generations. The study revealed that the female B. rubra, with an average total length of 5.17 ± 0.15 cm and weight of 1.61 ± 0.06 g, produced an average of 73.67 ± 7.09 eggs, 34.33 ± 5.13 total larvae, and exhibited a hatching rate of 46.67 ± 5.77%. The embryogenesis process commenced on the day of spawning (dps) and continued until the eggs hatched at 6 dps. Larvae development and yolk absorption occurred from 0 to 6 days post-hatching (dph). The study also examined the impact of different initial feeding options, with chopped Tubifex resulting in the most significant in- crease (p < 0.05) in length. The growth pattern of B. rubra larvae showed slow initial growth during the first seven days, followed by a rapid exponential growth phase from day 8 to day 39. Two generations of B. rubra (G1 and G2) were successfully bred in captivity, with G2 showing a better tendency for growth in length and weight compared to G1. Notably, there were no significant differences (p > 0.05) in reproductive success between the wild-origin broodstock (G0), G1, or G2. This research contributes valuable insights into the captive breeding of B. rubra and its early life stages, offering critical information for the conservation and sustainable management of this endangered species. Further research is needed to explore the long-term effects of domestication on behavior, physiology, and phenotypic diversity.

• Journal of Fisheries and Marine Sciences Education
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• v.14 no.2
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• pp.191-212
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• 2002

The economic and social bad influences of the illegal fishery bring about the results of the fishery resources exhaustion, of the fishery disorder and of the obstruction to sound management for fishery. The typical illegal fishery conducted in the coastal and offshore area of Korea can be divided as follows; fishery conducted by legally unauthorized method, fishery without permission from the Government, and fishery conducted in contravention of the laws and regulations concerning the fishing vessel, fishing gear and fishing method etc. The major reasons of origination of the illegal fishery in the coastal and offshore area of Korea are; Firstly, almost of the fishermen are poorly equipped in economical scale, Secondly, it is very easy to approach the illegal fishery because the domiciliation condition of the fishing village is deteriorated. Thirdly, almost of the fishermen are lacking in lawabiding spirit. Fourthly, the insolvent and unstable fisheries management policy with the lukewarm enforcement of the fisheries laws and regulations by the Government. Fifthly, the small scale family supporting fisheries are widespreaded. Sixthly, to retrieved the economical difficulties the fishermen are easily led astray the illegal fishery. As a conclusion the authors made some suggestions to stamp out the illegal fishery by this study. For the first, temptation fishermen into lawabiding fishery through intensification of the penal regulations is required. Second, simplification of the fishery type through combination of resemble fishing methods is required. Third, actual improvement of the fundamental fishery permission regime is required. Fourth, Introduction of the self-regulating or co-management system for the fishery management is required.

• Korean Journal of Ichthyology
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• v.28 no.3
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• pp.207-212
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• 2016

Sixteen specimens of Artediellus fuscimentus, belonging to the family Cottidae, were collected from the coastal waters off Samcheok and Donghae, Korea, in December 2010 and February 2015, respectively. The specimens are characterized by four preopercular spines, 12~13 second dorsal fin rays, 10~12 anal fin rays, a first preopercular spine with no minute spine on the inner side, and pectoral fin extending past the origin of the anal fin. We also analyzed 600 base pairs of the mitochondrial DNA cytochrome b sequence to confirm the taxonomic status of the specimens. The sequences of our specimens corresponded completely to those of Japanese A. fuscimentus, but differed from those of A. atlanticus (d=0.057~0.061). We propose the new Korean names "Eom-ji-hoet-dae-sok" for the genus Artediellus and "Eom-ji-hoet-dae" for the species A. fuscimentus.

• Journal of Aquaculture
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• v.20 no.4
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• pp.255-259
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• 2007

Genetic diversity among four populations of Chinese shrimp Fenneropenaeus chinensis from Narodo, Yeonggwang, Taean and Chinese Bohai Bay was assessed by amplified fragment length polymorphism (AFLP) DNA fingerprinting. Total numbers of AFLP bands generated (ranging from 251 to 254) and average percent of polymorphic bands (27.1 to 28.1 %) were similar in the four populations. Heterozygosity and genetic diversity within or among the populations were very low for the populations with average values ranging from 0.1177 to 0.1288 and from 0.1099 to 0.1194, respectively. Analyses of pairwise distance, Fst index and genetic similarity among the populations also revealed the similar results with very low genetic differentiation each other. These results suggest that all the wild populations tested in the present analysis may be belonging to the same genetic origin, and also that they may have a close relationship in genetic structure without any significant differentiation.

• Ocean and Polar Research
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• v.32 no.4
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• pp.351-359
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• 2010

This study examined extensive patches of floating green macroalgal (Ulva prolifera) mats in the northern East China Sea (ECS) using satellite images from mid May through July 2008 and field observation made during early August 2008 cruise. It was previously reported that the massive macroalgal blooms occurred in the coastal areas of Qingdao in China. During our field survey, researchers noticed widely distributed floating patches of macroalgal mats ranging in size from tens of centimeters to a few hundred meters in diameter. Meteorological data in the northern ECS showed high irradiance, high air-temperature, and predominant southerly winds in summer. In the study area during the survey period, surface waters were characterized by the Changjiang Diluted Water (CDW) mass, which contained high concentrations of nitrate and phosphate. The internal transcribed spacer (ITS) sequence of U. prolifera found in the northern ECS was the same as those of U. prolifera sampled from Qingdao blooms, suggesting a possibility that U. prolifera found in two regions would be derived from the same origin. We suggest that U. prolifera in the nearshore Jiangsu Province drifted into the northern ECS and proliferated under favorable meteorological and oceanographic conditions during the summer of 2008.

• Economic and Environmental Geology
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• v.29 no.1
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• pp.25-33
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• 1996

Stable isotopic ratios of the carbonate rocks and chemical compositions of the matrix of pebble bearing phyllitic rocks known as the Hwanggangri Formation, which are in hot debate on their origin such as tillite, debris flow and turbidite, were determined to interpret their depositional environment. Argillaceous matrix of the pebble bearing phyllitic rocks has a high content of CaO (av. 19.5%) and MgO (av. 8.3%), corresponding to calcareous sandy shale. No difference of chemical compositions including trace elements and REE is in the matrices between the Hwanggangri and the Kunjasan Formations. Carbonate rocks from the Okchon zone and outside of the zone range $-2.5{\sim}+6.1$‰ in ${\delta}^{13}C$ and $+5.8{\sim}+25.9$‰ in ${\delta}^{18}O$, indicating normal marine limestone. However, unusally $^{13}C$ enriched carbonate rocks might be deposited in the highly evaporated sedimentary basin. A wide variation of ${\delta}^{18}O$ values is responsible for metamorphism with a $^{18}O$ depleted meteoric water. Isotopic equilibrium temperatures by graphite-calcite geothermometer show a higher metamorphic temperature ($547{\sim}589^{\circ}C$) in the Okchon zone than those ($265{\sim}292^{\circ}C$) in the Samtaesan Formation of the Chosun group. Rhythmic alternation of relatively thin shale with thin limestone in the Kounri Formation is not cherty layer but thin limesilicate bed by metasomatic replacement. Judging from the isotopic and chemical compositions of the carbonate rocks and calcareous matrix of the pebble bearing phyllitic rocks, the Hwangganari Formation was deposited in the shallow marine environment favorable to debris flow.