• Korean Journal of Fisheries and Aquatic Sciences
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• v.17 no.3
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• pp.219-229
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• 1984

Physical and chemical survey on western channel of the Korea Strait was made using oceanographic data from July 25 to July 31, 1983. Four water types were distinguished at western channel: runoff of the Nakdong River, Tsushima Current Waters, Keoje Coastal Waters, and Ulsan Coastal Waters. Influence of the Nakdong River was greater at Southern East Coast near Yeong-Do Island in Pusan than at Keoje Coast. General characteristics of these four water types were as follows : For runoff of the Nakdong River, transparency was within 3 m, water colour chinese yellow (number 11), surface temperature $18{\sim}19^{\circ}C$, salinity less than $31\%0$, surface dissolved oxygen (D.O.) $4.5{\sim}5.0ml/l$, contents of phosphate $0.25{\sim}0.5{\mu}g-at./l$ ; these values were the highest among these four water types. For Tsushima Current waters, transparency was greater than 15 m, waters color blue (number $2{\sim}4$), surface temperature about $23^{\circ}C$, salinity $32{\sim}33\%0$, and surface D.O. greater than 5,0 ml/l. Phosphate, nitrate and silicate were less than 0.25, 2.0, and $2.5{\mu}g-at./l$, respectively; these values were the lowest among these four water types. Keoje Coastal Waters had low temperature ranging $20{\sim}21^{\circ}C$ at surface, and high salinity greater than $33\%0$. D.O. was less than 5.0 ml/l, phoshpate, $0.5{\mu}g-at./l$ nitrate and silicate were less than $3.5{\mu}g-at./l$. Ulsan Coastal Waters had the lowest surface temperature among these four types; surface temperature was less than $16^{\circ}C$, salinity greater than $33.5\%0$, and D.O., phosphate and nitrate had very high values. It seems that these high values resulted from upwelling phenomena.

• Journal of Aquaculture
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• v.14 no.3
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• pp.181-195
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• 2001

To stabilize the lantern cage culture system of Patinopecten yessoensis(Jay) in the eastern coast of Korean peninsula, optimum conditions such as time of transplantation, rearing density and depth, and time of harvest were identified. During the period from January 1991 to December 1998, the water temperature ranged from 4.7 to 21.4$^{\circ}C$ at 15-30 m depth and 4.9 to 25.7$^{\circ}C$ at the surface; these thermal ranges were within the optimal ranges (5-23$^{\circ}C$) prevailing at 15-30 m depth at surface water. Annual thermal changes indicated that the prevailing temperature during the years 1993 and 1996 was near optimum, but higher during the years 1994, 1997 and 1998, when mass mortality and growth retardation occurred. Salinity (32.0- 34.4$\textperthousand$) and dissolved oxygen (4.14 -8.11 $\mu\textrm{g}$/l) at 15 m depth were well within the optimum ranges. The chlorophyll concentrations (0.06 - 2.73$\mu\textrm{g}$/l) indicated that the study area was oligotrophic, although mass mortality did occur, when chlorophyll concentrations were high, especially in summer. Hence water temperatures and chlorophyll concentration are major factors related to survival and growth of the scallop. In terms of the shell height maximum growth occurred during spring (March-May; 8 - l3$^{\circ}C$) and fall (October-December; 11-l7$^{\circ}C$) in the lantern cage culture. Slow growth was recorded during late winter January-february; less than 7$^{\circ}C$) and mid-summer (August- September; more than 18$^{\circ}C$). Daily growth of shell height and total weight were 0.02∼0.24 mm and -0.07∼0.90 g at the rearing density of 12 individuals per net. Optimal .earing density in the lantern cage (ø50${\times}$20 cm) was 10∼15 individuals with the shell height of 5∼6 cm. The fastest growth rates were observed at 15∼20 m depth; however, it is recommended that 20∼30 m would be optimal. The scallops require 22 months to attain the commercial size of 10 cm shell height and 140 g total weigh, and are best harvested and sold during March-April.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.49-60
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• 2024

A region can be divided into cultivation zones based on homogeneity in weather variables that have the greatest influence on crop growth and yield. This study classified the cultivation zone of soybean using weather indices as a prior study to classify the agroclimatic zone of soybean. Meteorological factors affecting soybeans were determined through correlation analysis over a 10 year period (from 2013 to 2022) using data from the Miryang and Suwon regions collected from the soybean yield trial database of the Rural Development Administration, Korea and the meteorological database of the Korea Meteorological Administration. The correlation between growth characteristics and the minimum temperature, daily temperature range, and precipitation were high during the vegetative growth stages. Moreover, the correlation between yield components and the maximum temperature, daily temperature range, and precipitation were high during the reproductive growth stages. As a result of k-means clustering, soybean cultivation zones were divided into three zones. Zone 1 was the central inland region and southern Gyeonggi-do; Zone 2 was the southern part of the west coast, the southern part of the east coast, and the South Sea; and Zone 3 included parts of eastern Gyeonggi-do, Gangwon-do, and areas with high altitudes. Zone 1, which has a wide latitude range, was further subdivided into three cultivation zones. The results of this study may provide useful information for estimating agrometeorological characteristics and predicting the success of soybean cultivation in South Korea.

• Clean Technology
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• v.19 no.2
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• pp.95-104
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• 2013

Onsan Industrial Complex located in a nearby the Ulsan Petrochemical Complex and in the east of the coast. For this reason, air pollution substances emitted by Onsan Industrial Complex especially tend to have an effect on meteorological factors such as sea breeze. In this study, we assessed the frequency of sea breeze and mist using the meteorological data, and analyzed potential temperature and upper wind condition for assessment of atmospheric pollution concentration influenced by meteorological phenomena in a nearby the Onsan industrial complex. From an analysis results, when mist and sea breeze happened, each higher concentration phenomenon of $PM_{10}$ and $SO_2$ appeared each 57.2%, 71.8% and 46.6%, 57.7% respectively. Hence, we confirmed that meteorological phenomena such as mist and sea breeze had an effect on high concentration of air pollution substances in the research area. Analytical result of meteorological data in upper layer using potential temperature and wind condition, we confirmed that advection of air pollution substances emitted in Ulsan Petrochemical Complex by sea breeze have an effect on high concentration in Onsan Industrial Complex and nearby the residential area. In particular;concentration in Onsan Industrial Complex were higher than the average concentration by a factor of more than over 1.5 times when sea breeze by stable condition in atmospheric layer appeared.

• Strategy21
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• s.31
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• pp.142-163
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• 2013

Ieodo is a submerged rock within a Korea's Exclusive Economic Zone(EEZ) in the East China Sea with its most shallow part about 4.6m below the sea level which has no specific rights for the EEZ delimitation. The United Nations Convention on the Law of the Sea (UNCLOS) stipulates that any coastal state has the rights to claim an EEZ that stretches up to 200 nautical miles from its shore, except where there is an overlap with a neighboring country's claims. Korea claims that Ieodo is within its EEZ as it sits on the Korean side of the equidistant line and the reef is located on the Korea section of the continental shelf. China does not recognize Korea's application of the equidistance principle and insists that Ieodo lies on its continental shelf. According to UNCLOS, Ieodo is located in international waters, rather than one country's EEZ as the two countries have failed to reach a final agreement over the delimitation of the maritime border. This study seeks to understand the evolution of the People's Liberation Army Navy(PLAN) strategy as main obstacles for the EEZ delimitation between Korea and China. PLAN's Strategy evolves from "coastal defense" to "offshore defence", since the late 1980s from a "coastal defence" strategy to an "offshore defence" strategy which would extend the perimeter of defence to between 200 nm and 400 nm from the coast. China's economic power has increased It's dependence on open trade routes for energy supplies and for its own imports and exports. China want secure Sea Lane. PLAN's "offshore defence" strategy combines the concept of active defence with the deployment of its military forces beyond its borders. China's navy try to forward base its units and to achieve an ocean going capability. China's navy expects to have a 'Blue Water' capability by 2050. China insists that coastal states do have a right under UNCLOS to regulate the activities of foreign military forces in their EEZs. China protests several times against US military forces operating within It's EEZ. The U.S. position is that EEZs should be consistent with customary international law of the sea, as reflected in UNCLOS. U.S. has a national interest in the preservation of freedom of navigation as recognized in customary international law of the sea and reflected in UNCLOS. U.S. insists that coastal states under UNCLOS do not have the right to regulate foreign military activities in their EEZs. To be consistent with its demand that the U.S. cease performing military operations in china's EEZ, China would not be able to undertake any military operations in the waters of South Korea's EEZ. As such, to preserve its own security interests, China prefers a status quo policy and used strategic ambiguity on the Ieodo issue. PLAN's strategy of coastal defence has been transformed into offensive defence, Korea's EEZ can be a serious limitation to PLAN's operational plan of activities. Considering China'a view of EEZs, China do not want make EEZ delimitation agreement between Korea and China. China argues that the overlapping areas between EEZs should be handled through negotiations and neither side can take unilateral actions before an agreement is reached. China would prefer Ieodo sea zone as a international waters, rather than one country's EEZ.

• Korean Journal of Ichthyology
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• v.5 no.2
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• pp.151-159
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• 1993

Greeling, Hexagrammos otakii Jordan et Starks is commonly found at the coastal waters of Korea and Japan. The authors carried out the artificial insemination in the laboratory on Dec, 17, 1987, and reared the hatched larvae in an aquarium. The eggs were demersal and adhesive, and their diameters were 2.00~2.15mm. Color of yolk was light yellow in the early stage, and then turned to orange before hatching. The yolk had numerous tiny oil globules. Hatching began about 477hours after insemination under water temperature of $10.0{\sim}14.5^{\circ}C$. The newly hatched larvae were elongate in shape and 7.48~8.25mm in total length(TL) with 49~50 myomeres. The larvae absorbed the yolk material and oil globules completely in 5days after hatching and became postlarvae. In 17days after hatching, mean total length of the larvae was 9.85mm, and the caudal notochord flex at $45^{\circ}$. In 23days, total length reached 10.54mm. The part of the fin-fold of the future dorsal and anal fins became high. Spawning season of the Greenling is known to be from November to January in the southern coast of Korea.

• Journal of fish pathology
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• v.5 no.1
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• pp.29-35
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• 1992

This study was carried out in order to identify the biochemical and serological characteristics of Edwardsiella tarda isolated from cultured flounder, Paralichthys olivaceus in the east and south coast of Korea. During the year of 1990 and 1991, the number of isolated E. tarda were 131 strains. To identify the biochemical characteristics of them kinds of tests were conducted. The results represented that all the strains had the same biochemical characteristics, and their biochemical characteristics were no differences among strains. A serological analysis was carried out based on agglutination test with antiserum belonging to E. tarda serotype a (E-22), b (SU-138), c (SU-100) classfied in japan. The selected 10 isolates showed agglutinin titer of 5120-2560, 40-80 and below 40 against E. tarda serotype a, b and c, respectively. Sodium dodecyl sulfate polyacrylamide gel electrophoresis(SDS-PAGE) profiles of cell proteins of selected 10 isolates were showed no differences in kinds and volumes of proteins among strains.

• Microbiology and Biotechnology Letters
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• v.36 no.4
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• pp.268-275
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• 2008

In order to develop the multi-functional rhizobacteria that can exert positive effect on the growth of plants growing in the coastal sand dune located along East Coast of Korea, rhizospheral bacteria of 11 different plants from this area were isolated 1,330 rhizobacteria. Among these, 23 strains were able to produce auxin and had spectrum of antagonism toward various phytopathogenic microbes. To know the mechanism of this antifungal activity, these 23 strains were subjected to further analyses; 19 strains of these produced siderophore as determined by color reaction on CAS-blue plate, 4 strains produced antifungal cellulase as judged by color change on CMC-Congo red plate, 17 strains were able to utilized insoluble phosphate salts, also determined by clear zone formation on PVK medium. Identification of the strain was assigned to all 23 strains by l6s rDNA sequence analysed, and all were identified to be in the genus of Bacillus and Pseudomonas. One strain of these, denoted Pseudomonas fluorescens IB4-14, showed ACC deaminase activity which is known to be involved in the resistance of environmental stress such as salt and drought. Also, P. fluorescens IB4-l4 showed the germination stimulation and roots growth promoting activity on the in vivo assay of Lysimachia mauritiana Lam. (spoonleaf yellow loosestrife).

• The Korean Journal of Malacology
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• v.29 no.2
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• pp.147-154
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• 2013

In Incheon bay, mass mortalities of Manila clam associated with winter storms have been reported. In the present study we have monitored pathologic condition of the clams stranded on the tidal flats by the winter storms occurred in late March to early April in 2007. The field surveyed indicated that mortality of the Manila clam in the study areas ranged 10-15%. Condition index, a ratio of tissue weight to the shell weight, of the stranded clams was significantly lower than the non-stranded normal clams collected from the same locations (p < 0.05), indicating that the stranded clams were comparatively in poor physiological condition. Perkinsus olseni, the protozoan parasite was observed most of clams used in the analysis and the infection prevalence ranged 77-90%. The infection intensity of P. olseni determined using Ray's fluid thioglycollate medium (RFTM) cultivation and the 2M NaOH digestion assay indicated that the clams collected during late March and early April in 2007 involved 67,182-1,124,727 P. olseni cells/g tissue. The infection intensity of clams from Gung-Pyeung was significantly higher than the intensities observed from Dae-Bu and Young-Heung (p < 0.05). No clear correlation was found between the infection intensities of P. olseni in the non-stranded normal clams and the stranded clams. The stranded Manila clams were also infected with trematode parasite with the prevalence ranged 5 (Young-Heung) to 12.5% (Dae-Bu). The trematode-infected clams exhibited castrated follicles in the gonad, a typical sign of trematode infection. It was believed that mass mortality of Manila clam observed in this study was associated with the poor physiological condition as indicated by CI, although impacts of the parasite infection cannot be ruled out.

• Korean Journal of Ichthyology
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• v.23 no.3
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• pp.179-186
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• 2011

Slime flounder, Microstomus achne is distributed in the coastal waters of Korea, west sea of Japan, BoHai, Yellow sea and East china sea. They are mainly caught by bottom trawl net during winter, from December to March. Sexual maturation of slime flounder were investigated using samples collected from commercial catch in the southern coast of Korea from November, 2006 to March, 2007. The ovary of the slime flounder is a conical bag in shape and is bilateral structure develops lengthily from the posterior of the abdomen to the end of the anal fin. The testis also is bilateral in structure, usually located in small size in the abdomen. In females, the gonadosomatic index (GSI) were peaked in January (12.46), then decreased rapidly thereafter. Female GSI values plummeted to 2.72 in March just after spawning. Male GSI values were peaked in December (2.46) before in the spawning season, then decreased slowly thereafter. The reproductive cycle would be classified into three successive developmental stages : maturation stage (November to January), ripe and spawning stage (December to February), degenerative and resting stage (February to March). Relationships between the fish sizes in total length (TL) and the number of ovarian eggs (F), the body weights (BW) and the number of ovarian eggs were indicated by the exponential equation respectively: F=29.027TL-767.8 (r$^2$=0.7686), F=0.3998BW+24.288 (r$^2$=0.8919).