• Journal of Life Science
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• v.21 no.2
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• pp.176-182
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• 2011

Deep seawater (DSW) generally refers to seawater at depths equal to or greater than 200 meters. DSW is rich in inorganic materials which have attracted attention for its various applications. In this study we investigated the effects of the DSW upwelled from the East Sea, offshore Yang Yang (KangWon-do, Korea), on the expression of ${\mu}$-opioid receptor (MOR) of cultured rat hippocampal neurons. Neurons were grown in a minimal essential medium containing 10% (v/v) fetal bovine serum and either 25% (v/v) distilled water, or hardness (H) 800, or H 1000 DSW. Cultures grown in the presence of DSW with H 800 and H 1000 exhibited robust MOR immunoreactive signals in both neurons and astrocytes. Interestingly, the increase in MOR immunoreactive signals was more dramatic in astrocytes than in neurons. Statistical analysis revealed that the relative intensities for MOR clusters increased approximately 4-fold in astrocytes cultured in H 800 and H 1000 media. These increases were statistically very significant (p<0.001). In contrast, the increase in intensities for MOR immunoreactive signals was relatively less dramatic in neurons, where only the increase in the H 1000 culture was statistically very significant (p<0.001). These results indicated that DSW promotes expression of MOR in both neurons and astrocytes, and more significantly in the latter.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.13 no.6
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• pp.315-319
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• 2003

The quality, quantity, color, and characteristics were found out cultured seawater pearls and freshwater pearls. In the XRF measurement Ca chemical combinations were the main elements and Sr was detected at higher levels for the sea-water pearl and Si, S, Ca, Mn, P and other elements were found at higher levels for the fresh-water pearls. Such differences is judged to be caused by the ion diluted in sea and fresh water which affects the pearl elements. Although near similar structural peak was shown for the FT-IR measurement, the fresh-water pearl showed a lower peak for the 2344 wave. For the results of PL, the peak for fresh-water measured with Hd-Cd Laser at 455 nm was higher and with the Ar-ion Laser measurements, peaks were high at 545 nm and 570 nm for fresh-water pearl and sea-water pearls respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.23 no.4
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• pp.339-344
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• 1990

The composition of muscle lipids and their fatty acid composition of two groups of tilapia, cultured in fresh and seawaters, were investigated. The total lipid(TL) of seawater culture group is a little richer than that of freshwater culture. The neutral lipid(NL) is the most abundant in muscle lipids of two groups, followed by the phospholipid(PL) and glycolipid (GL). The increment of TL content seemed to depend upon triglyceride(TG) fraction, because large portions of lipids are consisted of TG. Phosphatidyl choline(PC), phosphatidyl ethanolamine and sphingomyelin were identified in PL, and the content of PC was the highest. The principal fatty acids of muscle lipids were 14 : 0, 16 : 0 and 18 : 0 as for saturated fatty acids, and 16 : 1, 18 : 1, 18 : 2 and 22 : 6 as for unsaturated fatty acids. In particular, high contents of 16 : 0 and 18 : 1 were observed in TL, NL and GL. However, low contents of 18 : 1 and 18 : 2 were observed in PL, while they were high in polyunsaturated fatty acids with 20 : 4, 20 : 5 and 22 : 6. In the meantime, no significant difference was observed in the composition of muscle lipids and their fatty acids between two groups cultured in seawater and freshwater.

• The Korean Journal of Malacology
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• v.26 no.2
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• pp.107-114
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• 2010

To evaluate the culture conditions in oyster-farming waters, chemical and biological measurements were made in seawater and oysters from six bays around Tongyeong in November and December 2003. Nutrient levels in the seawater were higher in the western area than in the eastern area, in contrast to particulate organic matter and dissolved oxygen levels. The mean total polycyclic aromatic hydrocarbon ({\sum}PAH) content of the oysters was 194.5-375.9 ng/g dry weight, with four-ring compounds constituting 34.1%-79.6% of PAH. Despite wide temporal variations, a "western > eastern" spatial distribution of PAH was apparent. These low concentrations of PAHs indicate that Tongyeong waters are pristine in terms of PAH contamination. Among the hemocytic biomarkers, only lysosomal activity was significantly reduced in Hansan-Goje Bay, but did not correlate closely with PAH content. This finding indicates that the impact of PAH on cultured oysters is negligible around Tongyeong waters.

• Journal of the Mineralogical Society of Korea
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• v.28 no.1
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• pp.9-16
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• 2015

A mineralogical analysis on the factors affecting the luster of pearls was carried out using gravity measurement, optical microscope observation, X-ray diffraction analysis, and scanning electron microscopy. We divided the seawater cultured pearls from Tongyeong into the following four types based on luster and shape; good luster and round (LR), lackluster and round (LLR), lackluster and baroque (LLB), and lackluster and two nucleus (LTN) pearls. Pearls with high-quality luster had slightly lower specific gravity as compared to pearls with low-quality luster, but both these types of pearls are within the specific gravity range of commercial pearls. Regarding the cross-sectional thickness of the mother-of-pearl layer, LR pearls showed a uniform thickness of about 0.3 mm in average. On the other hand, LLR pearls were characterized by relatively thinner, but uniform thickness. LTN and LLB pearls showed a tendency of significantly large variation in thickness even within a single pearl. For the surface of pearls, pearls with high-quality luster showed narrower and clearer growth lines of aragonite crystals as compared to pearls with low-quality luster. Pearls with high-quality luster were characterized by fewer aragonite crystal lattice defects as compared to pearls with low-quality luster, and the former showed parallel arrangement, thinner thickness, and less difference in thickness on the surface and inside. If a pearl has a prismatic layer, it is composed of aragonite with calcite in the prismatic and nacreous layer, and calcite content is very high in the lackluster pearl. Pearls without a prismatic layer were devoid of calcite irrespective of their quality of luster, and were composed of aragonite.

• Proceedings of the Microbiological Society of Korea Conference
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• 2005.05a
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• pp.28-32
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• 2005

Epifluorescence microscopy and direct viable counting methods have shown that only 0.01-0.1% of all the microbial cells from marine environments form colonies on standard agar plates. To culture novel marine microorganisms, high throughput culturing (HTC) techniques were developed to isolate cells in very low nutrient media. This approaches was designed to address microbial metabolic precesses that occur at natural substrate concentrations and cell densities, which are typically about three orders of magnitude less than in common laboratory media. Approximately 5000 cultures of pelagic marine bacteria were examined over the course of 3 years. Up to 14% of cells from coastal seawater were cultured using this method, a number that is 1400 to 140-fold higher than obtained by traditional microbiological culturing techniques. Among the cultured organisms are many unique phylogenetic lineages that have been named as new phyla (7), orders (2, 5, 12), families (3), and genera (1, 4, 6). Over 90% of the cells recovered by this method do not replicate in standard agar plating, the most common method of microbial cell cultivation.

• The Korean Journal of Malacology
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• v.32 no.3
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• pp.157-164
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• 2016

For the hygienic production of oyster at Goseong bay, this study investigated the marine bacteriological condition of the area from 2008 to April 2009. Average seawater temperature and salinity ranged $2.8-19.3.0^{\circ}C$ and 32.61-34.91 psu, respectively. The coliform group and fecal coliform of seawater ranged < 1.8-4,900 MPN/100 mL and < 1.8-700 MPN/100 mL, respectively. The coliform group of oyster (Crassostrea gigas) ranged < 1.8-13,000 MPN/100 g. Fecal coliform of oyster ranged and < 1.8-310 MPN/100 g. Only one of 140 samples was exceeded in the U.S NSSP standard (> 230 MPN/100 g) of fecal coliform. Fecal coliform in seawater was on the level of clean sea, below the U.S. NSSP standards, and the contents of fecal coliform and heavy metals in cultured oyster were also below the U.S. NSSP, heavy metal standards, showing that the sea area is bacteriologically safe.

• Korean Journal of Veterinary Research
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• v.47 no.3
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• pp.299-302
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• 2007

Neoheterobothrium hirame (N. hirame) is a large blood-feed gill-worm infecting the highly prized olive flounder. The present study was reported the occurrence and elimination of Neoheterobothrium infection from young cultured oliver flounder in the western coast of Korea. Flounder (weight 18-25 g, length 10-15 cm) were obtained from a cultured farm at Taean of Korea at May 2006. A lot of flounder died with serious anemia. We isolated N. hirame from the buccal cavity wall of dead flounder. Adult parasites were 5-15 mm in total length, with 4 pairs of clamps on the pedunculated haptor and isthmus region embedded in host tissue, while immature and sub-adults were identified the attachment to the gill filaments, rakers and arches with the clamps. All fish with infection were treated with 8% NaCl-supplemented seawater for 1 and 10 min at $22^{\circ}C$, respectively. The significant reduction in mortality (6.7%) was observed among fish treated with 8% salt water for 10 minutes, when compared with that of non-treatment group (100%).

• Environmental Analysis Health and Toxicology
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• v.14 no.3
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• pp.75-79
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• 1999

Due to increasing marine pollution there is a great possibility that seaweed is contaminated with polycyclic aromatic hydrocarbons (PAHs). To investigate the effect of processing on PAM removal from Porphyra tenera (laver) contaminated PAH, laver was contaminated with fluoranthene known to have a strong photoinduced toxicity, followed by washings and drying, which are usual processes for dried laver preparation. Sample at each step was collected and its toxicity was evaluated using cultured animal cells as well as analyzing PAH contents. Fluoranthene level in laver was significantly lowered by sequential washings with sea water and distilled water, but not by drying. Fluoranthene content in raw laver right after contamination was 221 ppm and decreased to 130 ppm by washings with seawater plus distilled water while its level was not lurker lowered by drying process. Cytotoxicity and photoinduced cytotoxicity in mammalian cells were significantly elevated in laver extracts containing fluoranthene. Cellular arylhydrocarbon hydroxylase (AHH), one of the biomarkers for cellular accumulation of PAH, was greatly induced by laver extract contaminated with fluoranthene. These results suggest that photoinduced toxicity and AHH activity can be used to monitor contamination of seafood by PAHs. Fluoranthene accumulated in laver was efficiently removed by sequential washings with seawater and tap water for 24 hrs and 12 hrs, respectively.

• Korean Journal of Ichthyology
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• v.29 no.1
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• pp.75-79
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• 2017

About 10% mortality occurred in cultured rainbow trout Oncorhynchus mykiss at a marine farm in Jeju in 2014. Diseased fish showed markedly abdominal distension and distended stomach. Although parasites, bacteria or viruses were not isolated from diseased fish, numerous Candida sp. were isolated from distended stomach. In experimental infection with Candida sp., mortality was not observed in most fish and clinical sign of distended stomach was not observed in the fish. These results suggest that Candida sp. may not be the etiologic agent of stomach distension syndrome. This is the first report of stomach distension syndrome in seawater farmed rainbow trout in Korea.