• Journal of Korean Society of Coastal and Ocean Engineers
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• v.25 no.4
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• pp.219-235
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• 2013

In order to investigate the changes in sea water characteristics and stratification due to operation of Shihwa tidal power plant, three dimensional numerical model is used. In summer, the density of inner part of Shihwa Lake is more affected by salinity than water temperature due to fresh water discharge. Before tidal power plant operation, the sea water characteristics in Shihwa Lake shows relatively high temperature and low salinity. After tidal power plant operation, water temperature decreases slightly and salinity tends to increase in Shihwa Lake. Also, density increases and stratification tends to weaken by mixing with sea water.

• The Korean Journal of Malacology
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• v.26 no.3
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• pp.211-215
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• 2010

The genus Perkinsus are parasitic protozoans that cause massive inflammatory responses in infected marine shellfish worldwide. This ultimately leads to great economic losses. This study examined the effects of water temperature and salinity on the formation of prezoosporangia and zoosporangia in order to understand the ecology of the pathogens. The induction of prezoosporangia from trophozoites occurred readily at higher water temperatures (20 and $30^{\circ}C$) and they had larger diameters than those incubated at lower temperatures (4 and $10^{\circ}C$). The formation of zoospores in prezoosporangia was also strongly influenced by water temperature and salinity; prezoosporangia exposed to water temperatures of 20 and $30^{\circ}C$ and salinities of 20 and 30 ppt had high rates of zoosporulation, while no or very low rates of zoosporulation were observed at temperatures below $10^{\circ}C$ or salinity below 10 ppt. Our data will be useful for the development of strategies to counter P. olseni proliferation in Korean waters.

• 한국해양학회지
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• v.16 no.1
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• pp.31-37
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• 1981

Saline water movements in relation to tidal condition and river discharge in the estuary of the Nakdong River are discussed on the basis of the observation data. The difference of salinity between the surface and the bottom layer was 1∼3 at spring tide forming a vertically homogeneous estuary, while at neap tide, it ranges up to 7∼15 indicating a sharp salt wedge. The maximum salinity appeared approximately at an hour after the high water, that is, three hours after the landward velocity maximum, while the salinity maximum at around an hour after the low water, that is, three hours after the seaward velocity maximum. The density current speed at a section located 10km landward from the river mouth was observed approximately to be 45cm sec$\^$-1/ at 8m layer.The relations between the salinity at Gupo and the river discharge at Jindong are estimated by means of the least square method. The maximum length of the salt wedge is calculated approximately to be 22km at neap tide and 16km at spring tide, which is in accordance with the observed data. The salinity influence area is deduced to be 45km at spring tide and 35km at neap tide. The diffusion coefficient of salinity was estimated approximately to be 1.5 10$\^$8/$\textrm{cm}^2$ sec$\^$-1/ at Samrak and 8 10$\^$5/$\textrm{cm}^2$ sec$\^$-1/ at Gupo at neap tide, while it was 1.4 10$\^$7/$\textrm{cm}^2$ sec$\^$-1/ at Dongwon at spring tide.

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.32 no.2
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• pp.125-131
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• 1996

In order to investigate the relation between the environmental properties and the catch fluctuation of set net fishing grounds located in the coastal waters of Yosu, oceanographic observations on the fishing grounds were carried out by the training ship ofYosu Fisheries University from January, 1990 to September, 1992, and the data obtained were compared with the catch data from the joint market ofYosu fisheries cooperative society from 1984 to 1993. The resuItes obtained are summerized as follows : 1. The ranges of water temperature and salinity in the fishing ground was 7.0 to $27^{\circ}C.$and 26.6 to 33.2${\textperthousand}$, and water temperature increased from March to August and decreased from September to February of following year. 2. The salinity in the fishing grounds was relatively high without significant changes from November to June of the following year. From July, however, the salinity decreased to continue a low value till September and then increased. The salinity in the fishing ground was dominated mainly by the precipitation and its variation was large at the north entrance of set net fishing ground, influenced greatly by the land waters from the river of Somjin, but small in the offshore of the fishing grounds. 3. The fishes caught by the set nets were arranged in order of catch as follows; Spanish mackerel> Horse mackerel > Sardine > Anchovy > Hair tail. The catches of Anchovy and Sardine were high in April to May and those of Hair tail in June to July, but Spanish mackerel and Horse mackerel were caught for whole period of fishing. Spanish mackerel was caught most in September and least in April and their means were largest in August and smallest in June. 4. The ranges of optimum water temperature for fishing by the set nets was 13.5 to $25^{\circ}C.$, and in the ranges the catches increased with increasing temperature. The ranges of optimum salinity for fishing varied between 25.0 and 32.0${\textperthousand}$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.335-340
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• 1983

The effects of water temperature, salinity, and silt and clay on the photosynthetic activity of Porphyra yezoensis were measured. The rate of photosynthesis of P. yezoensis increases as the water temperature rises in the range of $8{\sim}16^{\circ}C$ and begin to decrease at $18^{\circ}C$. In the salinity range of $21.5{\sim}33.5\%0$, the rate of photosythesis of P. yezoensis was increased in the sea water of $29.5\%0$ salinity and decreased in $21.5\%0$ salinity. The rates of photosynthesis of P. yezoensis were significantly decreased with increase of the concentration of silt and clay and the time of exposure to suspended silt and clay. Of the combined effects of salinity, and silt and clay on the photosynthetic activity of P. yezoensis, the effects of silt and clay were higher in the low salinity of $21.5\%0$ and $33.5\%0$. The wet weight of P. yezoensis showed a remarkable loss with increase of the concentration of silt and clay and the time of exposure to silt and clay.

• Journal of the korean society of oceanography
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• v.33 no.1-2
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• pp.1-7
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• 1998

In the western Weddell Sea, winter mixed layer is characterized by near-freezing temperature and higher salinity due to brine injection through sea-ice formation. This layer becomes Winter Water being capped by warmer and less saline Antarctic Surface Water during the sea-ice melt-ing season. In this study, Winter Water was preliminarily identified by the oxygen isotopic com-positions. The ${\delta}^{18}$O values of Winter Water show the progressively increasing trend from south to north in the study area. It presumably reflects the enhanced mixing with Antarctic Surface Water due to the extent of influence by low S'"0 value of sea-ice/glacier meltwater. Correlations between salinity and 6'"0 values of seawater can be used to more generally characterize Winter Water with a view to identification. However, the prediction on the degree of mixing from these relationships needs more detailed isotope data, although this study allows the oxygen isotopic composition of seawater as a tracer to identify the water mass.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.49 no.1
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• pp.61-73
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• 2016

Water mass distribution and currents were investigated off the east coast of Korea near the Hupo Bank using the CTD and ADCP data from June to August 2010. The typical water masses were: (1) Tsushima Surface Water (TSW) from the East Korean Warm Current (EKWC) in the surface layer, (2) a shallow thermocline at 20-30 m depth, (3) Tsushima Middle Water (TMW) of high salinity (>34.2) below the pycnocline, (4) North Korean Cold Water (NKCW) of low salinity (<34.05) and low temperature (<4°C) in the lower layer. In June, a double eddy was observed in which a cold filament intruded cyclonically from the south around a pre-existing cold-core eddy. A burst of strong southward current was recorded in mid-August due to a warm filament from the meandering EKWC. Current in the N-S direction was predominant due to topographic effects, and the direction of the northward EKWC was frequently reversed in its direction due to the eddy-filament activity, whereas the influence of the wind was not noticeable. The vertical structure of the current was of a two-layer system, with the northward EKWC in the upper layer and weak southward flows corresponding to the North Korean Cold Current (NKCC) in the deeper layer.

• Asian-Australasian Journal of Animal Sciences
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• v.18 no.2
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• pp.296-300
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• 2005

Human-induced soil salinity is becoming a major threat to agriculture across the world. This salinisation occurs in both irrigated and rain-fed agricultural zones with the highest proportions in the arid and semi-arid environments. Livestock can play an important role in the management and rehabilitation of this land. There are a range of plants that grow in saline soils and these have been used as animal feed. In many situations, animal production has been poor as a result of low edible biomass production, low nutritive value, depressed appetite, or a reduction in efficiency of energy use. Feeding systems are proposed that maximise the feeding value of plants growing on saline land and integrate their use with other feed resources available within mixed livestock and crop farming systems. Salt-tolerant pastures, particularly the chenopod shrubs, have moderate digestible energy and high crude protein. For this reason they represent a good supplement for poor quality pastures and crop residues. The use of salt-tolerant pasture systems not only provides feed for livestock but also may act as a bio-drain to lower saline water tables and improve the soil for growth of alternative less salt tolerant plants. In the longer term there are opportunities to identify and select more appropriate plants and animals for saline agriculture.

• Journal of the Korean Society for Marine Environment & Energy
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• v.4 no.2
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• pp.25-34
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• 2001

/sup 226/Ra and /sup 228/Ra analysis were carried out at the representative station of Masan Bay from May to August, 1999. The high activities of /sup 226/Ra and /sup 228/Ra in the surface water were appeared in rainy season (August, 1). However, there is no significant variation in concentrations in the other season. A high negative linear correlation between /sup 226/Ra activities and salinity in the surface water suggests that /sup 226/Ra activity in the surface water was controlled by simple mixing between the two end-members low salinity high /sup 226/Ra activity water of inner Bay and a high salinity low /sup 226/Ra activity water of the continental shelf water out of Bay. /sup 226/Ra activities below the surface mixed layer were higher than those of expected level from the /sup 226/Ra versus salinity. And also /sup 228/Ra//sup 226/Ra ratios in the bottom water were lower compared to those in surface water due to the presence of potential source of /sup 226/Ra below the surface mixed layer. However, it is known that /sup 228/Ra compared to /sup 226/Ra is enriched in bottom sediments and pure water. Therefore, the most probable sources for low /sup 228/Ra//sup 226/Ra activity ration is submarine ground water discharge. Further studies are required to quantify the various sources of /sup 226/Ra and /sup 228/Ra and their relative contributions.

• Journal of information and communication convergence engineering
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• v.9 no.4
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• pp.475-482
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• 2011

In this research, we have attempted to estimate the water quality of fish farms in terms of parameters such as water temperature, dissolved oxygen, pH, and salinity by employing observational data obtained from a coastal ocean observatory of a national institution located close to the fish farm. We requested and received marine data comprising nine factors including water temperature from Korea Hydrographic and Oceanographic Administration. For verifying our results, we also established an experimental fish farm in which we directly placed the sensor module of an optical mode, YSI-6920V2, used for self-cleaning inside fish tanks and used the data measured and recorded by a environment monitoring system that was communicating serially with the sensor module. We investigated the differences in water temperature and salinity among three areas - Goheung Balpo, Yeosu Odongdo, and the experimental fish farm, Keumho. Water temperature did not exhibit significant differences but there was a difference in salinity (significance <5%). Further, multiple regression analysis was performed to estimate the water quality of the fish farm at Keumho based on the data of Goheung Balpo. The water temperature and dissolved-oxygen estimations had multiple regression linear relationships with coefficients of determination of 98% and 89%, respectively. However, in the case of the pH and salinity estimated using the oceanic environment with nine factors, the adjusted coefficient of determination was very low at less than 10%, and it was therefore difficult to predict the values. We plotted the predicted and measured values by employing the estimated regression equation and found them to fit very well; the values were close to the regression line. We have demonstrated that if statistical model equations that fit well are used, the expense of fish-farm sensor and system installations, maintenances, and repairs, which is a major issue with existing environmental information monitoring systems of marine farming areas, can be reduced, thereby making it easier for fish farmers to monitor aquaculture and mariculture environments.