• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.139-143
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• 2014

This study was conducted to investigate the germination and growth response by Salinities of Spergularia marina Griseb grown in the western coastal region in South Korea. The germination was investigated for 10 days at temperature $10^{\circ}C$, $15^{\circ}C$, $20^{\circ}C$, $25^{\circ}C$ in order to examine the germination of Spergularia marina Griseb by NaCl concentration 0.0, 0.3, 0.5, 1.0, 2.0%. The germination of NaCl concentration 0.0~1.0% was 90% over at $15^{\circ}C$ treatment, but the germination of NaCl concentration 2.0% was 0% at all temperature treatments. To identify the growth response of Spergularia marina Griseb according to the salinity, Spergularia marina Griseb was cultivated for 8 weeks in Hoagland culture medium and sea water. In nutrient solution culture, growth was best in NaCl 50mM among 0~400 mM concentrations and in 0, 12.5, 25, 50, 100% of sea water, growth was best in 12.5% (dilution ratio with fresh water) treatment. Spergularia marina Griseb's inorganic component contents according to salinity showed that $Na^+$ content increased, but contents of $K^+$, $Ca^+$, $Mg^+$ decreased. As a result, appropriate condition for Spergularia marina Griseb's germination is considered to be maintained at $15^{\circ}C$ and in less than NaCl 1.0% of salinity. When nutrient solution culture, NaCl 0.3% of treatment level is considered to be the optimum salinity.

• Journal of the Korean Society of Food Science and Nutrition
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• v.42 no.10
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• pp.1664-1672
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• 2013

Solar salt is manufactured naturally, and therefore, it contains insoluble substances such as sandy compounds. This study is performed in order to effectively produce clean sea salt by removing the impurities in sea salt through filtration and evaporation in a vacuum condition. Brine was concentrated and crystallized at $90^{\circ}C$ by a rotary vacuum evaporator, which was then recovered as salt crystals by filtration, and then the salt was dehydrated. Manufacturing yields were determined by the amount of water evaporation. Brine was concentrated to 40%, 50% and 60% of the initial volume of brine and manufactured salt were designated as 40S, 50S and 60S, respectively. The salt produced by this process is called ESBS (evaporated salt with brine from salt-farm). The yield of 40S, 50S and 60S were 7.22%, 10.79% and 15.06%, respectively. The NaCl concentration of 40S and 50S were 90.38% and 91.16%, respectively. From a sensory evaluation analysis, the most tasty salt was 40S and the bitter salt was 60S. The average contents of sand compound and insoluble substances in ESBS were 0.001~0.012% and 0.067~0.12%, respectively. The mineral compositions, such as Na, Mg, K, and Ca of 40S and 50S were similar with those of the natural solar salt. In solubility tests, the solubility (g of salt/100 mL $H_2O$/sec) of 40S, 50S, and 60S was 0.69, 0.70, and 0.69, respectively. On the other hand, the solubility of natural solar salt was 0.47. By comparing the water reabsorption rate analysis results, water reabsorption rate of 40S and 50S was about 3 to 5 times lower than that of the solar salt. In the aspects of physical and chemical properties, such as minerals, impurities, solubility and moisture re-absorption rate, salts developed in this study are judged to be better than that of the general solar salt.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.1
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• pp.15-22
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• 1995

To study ecological properties of Vibrio cholerae non-Ol and Vibrio mimicus which have been described as new food poisoning bacteria recently, the influence of factors such as temperature, salinity, pH and chemical oxygen demand (COD) on detection rate and density of these bacteria were evaluated. Fifty four seawater samples and 49 bottom deposit samples from estuary of Kum river from March 26th, 1993 to February 22nd, 1994 were used for this study. The detection rate of V cholerae non-O1 were $16.7\%$ for seawater and $10.2\%$ for bottom deposit, respertively. The total detertion rate of V. cholerae non-O1 $(11.7\%)$ was a little higher than V mimicus $(10.7\%)$. Both V choierae non-O1 and V. mimicus were mainly detected in estuary water of which showed temperature $24^{\circ}C$ above and salinity $10\%o$ below. These bacteria were also detected in bottom deposit on January when the water temperature was $3.5^{\circ}C$. From these results, we supposed that temperature, salinity and organic material were important factors to growth of V. cholerae non-O1 and V. mimicus. V cholerae non-O1 might be grown better than V. mimicus under the fluctuating aquatic environmental condition such as salinity.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.2
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• pp.296-301
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• 1998

The physical and chemical characteristics were examined in the southern sea of Korea including the Cheju Strait, and the entrance of the Korea Strait in the period of May 30 to June 8, 1995. The results are as follows. Firstly, the variation ranges of the temperature and salinity at the Cheju Stratit during 24 hours observation were larger in the surface layer than that in the deep layers. Secondly, daily variations of nutrients show that total inorganic nitrogen, phosphate phosphorous, and silicate silicon concentration are higher at night than at day. Thirdly, water temperature and salinity distributions show highest values at the entrance of Korea Strait, which is thought to be influenced directly by Tsushima Warm Current, while they show the lowest values in Cheju Strait. This means that the surface waters in Korea Strait are greatly influenced from the entrance of Korea Strait and bottom waters is greatly influenced from Cheju Strait. Fourthly, nutrients distribution shows highest values in Korea Strait but dissolved oxygen shows lowest values in the area. These seem to be caused by the oxygen consumption used in the inorganization of nutrients to decompose organisms and the liquidation of nutrients.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.3
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• pp.317-319
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• 1999

The ciliate, Vorticella was often observed in the rotifer mass culture tanks as common co-existing organism. This Vorticella performed as a predator for aquatic bacteria population in the rotifer mass culture tanks. This study was carried out to investigate a cyst formation medium of Vorticella in the laboratory for keeping Vorticella seed. The test organism Vorticella sp. was isolated from culture water of rotifer mass culture tanks. The cyst of Vorticella was formed by dried-method for the formation and maintainance of cyst. MCCF (Marine Ciliate Cyst Formation) medium was used for cyst formation (incystment), preservation and return to moving cell (excystment) of the marine ciliate, Vorticella sp. The cyst shape and size were ellipical type and $30.51 \pm1.98\;\mu$m (Avg. $\pm$ SD) of minor axis and $28.89 \pm2.12\;\mu$m (Avg. $\pm$ SD) of minor axis (n=10), The Vorticella cyst was kept in the room temperature ($10\~35^{\circ}C$) and total dark condition (24D:0L) during 1 year. The preserved cyst was transferred to moving cell state (excystment) only by the addition of fresh sea water in the MCCF medium. The five Vorticella sp. moving cells of excysted from cysts showed the growth up to 912$\pm$64 cells/10 ml in MCCF medium during the culture period of 16 days. This MCCF medium was very useful tool for cyst formation and species preservation of marine ciliate Vorticella.

• Korean Journal of Plant Resources
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• v.21 no.4
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• pp.299-303
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• 2008

Two-year-old seedlings of Ilex rotunda were grown under control (full sunlight) and three different shading condition. Those conditions were full sunlight (PPFD 1600${\mu}mol\;m^{-2}\;s^{-1}$), 30% (PPFD 400${\mu}mol\;m^{-2}\;s^{-1}$), 50% (PPFD 250${\mu}mol\;m^{-2}\;s^{-1}$) and 70% treatment (PPFD 100${\mu}mol\;m^{-2}\;s^{-1}$). Total chlorophyll contents were inverse proportion to light intensity. Seedlings under full sunlight showed the highest photosynthetic activity such as photosynthetic rate, intercellular $CO_2$ concentration and water use efficiency. Photosynthetic activity trend was increased at the higher light intensity than the lower treatment over PPFD 500${\mu}mol\;m^{-2}\;s^{-1}$. Especially, seedlings under 70% treatment showed the worst photosynthetic activity at high light intensity. That result was regular for adapted plant in low intensity environment. Leaf area was also inverse proportion to light intensity, while dry weight per leaf area was shown the opposite trend.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.10 no.3
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• pp.164-170
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• 2005

To investigate the aquatic environmental factors and processes controlling primary production in the Seomjin River estuary, chlorophyll a, nutrients, pH, SS, DO, temperature, salinity and primary productivity were measured in February, April, August and October, 2001. Primary productivity values ranged between 50.7 and 14,120.3 mg C $m^{-3} day^{-1}$ during the sampling period. In contrast to other estuaries, light condition did not seem to be the important limiting factor far primary production due to high water-column transparency during most of the time. The autumn bloom occurred in regions where salinity values ranged between 10 and 20 psu. This phenomenon appeared to develop every year and deserves further investigation. The behavior of nutrients, which is one of the major factors controlling the primary productivity, appeared to be governed by salinity regimes. The main source of nitrogenous nutrients seemed to be the freshwater runoff from the Seomjin River. However, that of phosphorus seemed to be from the industrial wastewater in Gwangyang area. The primary pro-duction of phytoplankton in the study area varied with space and time, showing a close correlation with water column transparency, and exhibited higher values compared to those of adjacent coastal regions in Gwangyang Bay.

• Journal of fish pathology
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• v.26 no.3
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• pp.283-287
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• 2013

The susceptibility of marine medaka, Oryzias dancena to fish pathogenic viruses (infectious pancreatic necrosis virus (IPNV), viral hemorrhagic septicemia virus (VHSV), hirame rhabdovirus (HIRRV), infectious hematopoietic necrosis virus (IHNV), and lymphocystis disease virus (LCDV)) was investigated. The cumulative mortalities of fish immersed with IPNV (experimental condition: $15^{\circ}C$ sea water (SW)), VHSV ($15^{\circ}C$ SW), HIRRV ($15^{\circ}C$ fresh water (FW)) were 30%, 40% and 60%, respectively. In the fish immersed with IPNV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), VHSV ($15^{\circ}C$ FW, $18^{\circ}C$ FW and SW), HIRRV ($15^{\circ}C$ SW), IHNV ($15^{\circ}C$ FW and SW), LCDV ($15^{\circ}C$ FW and SW, $18^{\circ}C$ FW and SW), and mock-challenged group, mortality rate was less than 10%. IPNV, VHSV and HIRRV were re-isolated from the dead fish. These results suggest that marine medaka is susceptible to IPNV, VHSV and HIRRV, although their susceptibility depends on the environmental conditions.

• Journal of Practical Agriculture & Fisheries Research
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• v.24 no.1
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• pp.5-13
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• 2022

Sunbigi tree(Vitex rotundifolia L.f.), which grows wild in the southern part of Korea and along the coast of the West Sea, has a lot of useful value in terms of resource utilization. Since ancient times, it has been used as folk medicine or herbal medicine in the private sector. Although the leaves and stems have a strong scent, the fruit also has a strong scent, so there are some studies on extracting essential oil from the fruit of Sunbigi tree and analyzing the ingredients, but there are few studies on the fragrance component by extracting hydrosol. The reason is that the fruits are hard and it is difficult to identify the active ingredients contained in the general extraction method. Therefore, in this study, the results of analyzing the components contained in the fragrance of hydrosol obtained by extracting hard fruits at high temperature by different extraction methods are as follows. 1. The extraction condition with the highest flavonoid content was 30.57 mg/g with ethanol, followed by hot water extract at 18.26 mg/g and water extract at 9.69 mg/g with the lowest. 2. As a result of distillation extraction from the fruit of Sunbigi tree, the fragrance of hydrosol is 3-Methyl-2-butenoic acid, cyclobutyl ester, Eucalyptol, L-alpha-Terpineol, 1H-Cycloprop[e]azulen-7-ol, decahydro-1 ,1,7-trimethyl-4-methylene-, [1ar-(1a.alpha.,4a.alpha.,7.beta.,7a.beta.,7b.alpha.)] were found to be many.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.370-379
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• 2007

Short-term variations of phytoplankton community structure in the southeast coastal waters of Korea from July to September in 2006 were investigated with data set of phytoplankton, chemical and physical water properties, and meterological data. A total of 11 sampling sites of 4 different depths (surface, 5 m, 10 m, and bottom) were visited on July 11-14, July 24-26, August 7-10, August 21-24 and September 5-8. We identified 151 species in 63 genera of phytoplankton in which diatoms were the most diverse group composed of 92 species in 37 genera. Dinoflagellates were the second diverse group of 52 species in 22 genera. The other groups include 7 species in 4 genera including Raphidophytes, and Euglenophyta. After rainy season, excessive nutrients from adjacent streams to the stratified water column proliferates Chaetoceros group in July. But biomass of phytoplankton and nutrient concentrations were decreased during the period of a drought in August. However, Chaetoceros was the most dominant genera in all depths of the first, second, third and fifth cruises, except the 4th cruise on August 21-24 when dominant group were dinoflagellates including Gymnodinium spp. and Cochlodinium polykrikoides. The characteristic of phytoplankton community and environment condition during summer 2006 can be summarized as: 1) low concentration of nutrients caused by a long lasting drought in August 2) no summer outbreak of C. polykrikoides because the strength of offshore waters was weak than other years, and 3) Chaetoceros spp. was the dominant species despite short period appearance of dinoflagellates.