• Journal of the Korean earth science society
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• v.21 no.5
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• pp.541-552
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• 2000

The variations of physical properties due to inflow of seawater by sluice gates operation were observed in Shihwa Lake. The distributions of salinity and temperature were investigated at 11 stations during February, 1997 to July, 1998. The salinity of water mass in Shihwa Lake before gate operation was ranged below 15psu and strong stratification due to inflow of seawater was observed at the depth of 11 m. In July 1997, temperature difference of 10^{\circ}C$ was occurred between the surface and bottom water due to strong solar radiation. During October 1997 to February 1998, inversion of temperature distribution, which the temperature of bottom water was higher than that of surface water, was observed. In July 1997, temperature, salinity, current speed and current direction were investigated by RCM-7 at St.3 for 56 days. When sea water was intruded in Shihwa Lake, the symmetric distribution of temperature and salinity was observed and it seems to be resulted from inflow of seawater with low temperature and high salinity. After January 1998, salinity of Shihwa Lake was increased over 30psu due to continuous gate operation and the stratification was weakened.

• The Korean Journal of Malacology
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• v.20 no.2
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• pp.107-110
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• 2004

The filtration rate and oxygen consumption of Anadara granosa bisenensis were measured at 4 different temperature (10$^{\circ}C$, 15$^{\circ}C$, 20$^{\circ}C$, and 25$^{\circ}C$) and 4 different salinity levels (20, 25, 35, and 40 psu), using an direct method under laboratory conditions. The samples were divided into two groups: a large-sized group (shell length: 34.58 ${\pm}$ 2.23 mm, body weight: 12.43 ${\pm}$ 0.44 g) and a small-sized group (shell length: 20.60 ${\pm}$ 0.85 mm, body weight: 4.41 ${\pm}$ 2.30 g). Filtration rate and oxygen consumption increased with the increase of various temperatures and salinity levels. Also, the filtration rate and oxygen consumption of the small-sized group were higher than those of the large-sized group. These results indicate that the filtration rate and oxygen consumption of Anadara granosa bisenensis depends on environmental conditions, especially on water temperature and salinity.

• Korean Journal of Environmental Biology
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• v.29 no.1
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• pp.11-16
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• 2011

Distribution characteristics of two dominant paracalanids of the family Paracalanidae on temperature and salinity were studied in the brackish and coastal waters from the West and South coasts of Korea. Bestiolina coreana mainly occurs in a range of 29.8~31.3 psu salinity and temperature of more than about $20^{\circ}C$, while Paracalanus parvus s. l. mainly occurs in a range $17{\sim}20^{\circ}C$ temperature and more than 30 psu salinity. The fact clearly indicates that temperature and salinity was a major factors in spatio-temporal distribution between these two paracalanids.

• Journal of the Korean Society for Marine Environment & Energy
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• v.12 no.4
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• pp.235-247
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• 2009

In order to elucidate the cause of Cochlodinium polykrikoides blooms in the Korea southern coastal water, we investigated observational data of water temperatures and salinities in summer and winter, obtained from the stoppage of ship by NFRDI (National Fisheries Research and Development Institute) as well as composite images by NOAA from 1995 to 2008. Cochlodinium polykrikoides blooms occurred when water temperature was approximately $25.0{\sim}26.0^{\circ}C$ and salinity was 31.00 psu on average in Narodo neighboring seas. Different thermohaline fronts were observed between the Korea southern coastal water and the open sea water in summer and winter, respectively. That is, in winter four fronts were observed between the Korea southern coastal water with low temperature and low salinity, intermediate water originated from Tsushima Warm Current, Tsushima Warm Current with high temperature and high salinity, and the China coastal water with low temperature and low salinity. In contrast, in summer two fronts were observed between the Korea southern coastal water with low temperature and high salinity, Tsushima Warm Current with high temperature and low salinity, and the China coastal water with high temperature and high salinity. These thermohaline fronts also proved to be formed by two water masses with a different physical property, in terms of T-S diagrams. Consequently, we noticed that C. polykrikoides blooms occurring in Narodo neighboring seas in summer had a close relationship with thermohaline fronts observed between the Korea southern coastal water and Tsushima Warm Current.

• The Korean Journal of Malacology
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• v.21 no.1
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• pp.13-17
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• 2005

In this study, the influence of water temperature and salinity on sand ejection of Manila clams, Ruditapes philippinarum, was investigated. The result showed that, under different water temperature, the highest quantity of sand ejection was at $20^{\circ}C$, the value of which was 0.091 g, while the smallest one was only 0.058 g at 0$^{\circ}C$. The highest releasing rate, 95.79%, could be seen in $20^{\circ}C$ group, while $0^{\circ}C$ group was the lowest one, 85.29%. Under different salinity, 30 psu group had the highest value, 0.057 g, and 0 psu (freshwater) group was the lowest one, only 0.026 g. At the same time, the highest releasing rate appeared at 25 psu, which was 90%. 0 psu group was the lowest one in releasing rate, 60.47%. According to these results, we recommend that the clams should be placed into the clear seawater with about 25 psu of salinity at near $20^{\circ}C$ to let the clams perform the self-depuration. Better quality of clams containing less impurity in the aquaculture and commerce could be obtained from this pre-treatment.

• Journal of Marine Life Science
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• v.1 no.1
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• pp.50-55
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• 2016

Glucose was continuously increased as time was elapsed under the temperature at 6℃ and 4℃. NH₃ was significantly increased at 4℃. AST was increased as temperature and salinity were decreased which indicated that it was affected by temperature, salinity and interaction of temperature×salinity. ALT was significantly increased as temperature was decreased. Free amino acid contents, excluding aspartic acid, threonine, serine and glycine were increased as temperature was decreased. This decreasing tendency was also observed when salinity was decreased. Taurine, aspartic acid, glutamic acid and arginine were significantly increased as salinity was decreased, while glycine, alanine, methionine, tyrosine, and histidine were decreased as salinity was decreased. The result of this study suggested that transport condition to minimize the stress is considered in the range of 30~34 psu, 8~10℃.

• Korean Journal of Ichthyology
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• v.21 no.3
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• pp.158-166
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• 2009

To obtain the fundamental data for the mass seedling production of grunt, Hapalogenys nitens, we investigated the influence of salinity and cold water temperature on hatching and survival of eggs and growth and survival of larvae and fry. In regards to salinity, we surveyed the hatching rate and floating rate of fertilized eggs, the floating rate and survival rate of hatching larvae, and the survival and growth of fry. In respect to cold temperature, we investigated the influence of degree of daily temperature decrease, acute temperature shock, and slow temperature decreases on the survival, feeding and swimming activities of fry. In the salinity experiment, the hatching and floating rates of fertilized eggs, and the floating and survival rates of hatching larvae, were shown to be higher in seawater than in brackish water. Growth and survival of larvae and fry were not different between seawater (25~32 psu) and brackish water (5~20 psu), but were significantly lower in freshwater. In the cold-temperature test, three tests showed that rearing of fry in cold water and acutely decreasing water temperature to less than $10^{\circ}C$ reduced the survival, feeding and swimming activities of the fry. Therefore, we concluded that low salinity (less than 32 psu) could reduce the hatching rate and survival of eggs, but the growth and survival of fry were not influenced by salinity, and cold water (less than $10^{\circ}C$) decreased metabolism of grunt. During winter, we found a low-temperature limit at $8^{\circ}C$.

• Proceedings of the Korean Environmental Health Society Conference
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• 2004.06a
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• pp.207-209
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• 2004

This study was performed to estimate the effects of salinity and washing of food wastes on temperature, pH, and salinity in aerobic composting of food wastes. Weight ratios of food wastes to water in washing were 1:0(Control), 1:1(W-1), 1:2(W-2), 1:3(W-3) and 1:4(W-4), respectively. Ratios of food wastes to wood chips in reactor of Control, W-1, W-2, W-3 and W-4 were 5kg:5L, respectively. Reactors were operated for 24 days with 1 hour stirring by 1 rpm and 2 hours aeration per day. The increase in the ratio of food wastes to water used in washing resulted in the decrease of the highest reaction temperature and the elongation of the high temperature reaction period. The lowering of the ratio of food wastes to water used in washing resulted in faster pH increase The final salinities of Control, W-1, W-2, W-3 and W-4 were 0.95%, 0.73%, 0.65%, 0.57% and 0.41%, respectively.

• 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${\textperthousand}$.

• Journal of Marine Life Science
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• v.7 no.2
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• pp.213-220
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• 2022

This study was conducted to investigate the effect of environmental factors such as water temperature and rearing density on the survival and growth of Litopenaeus vannamei under low salinity conditions. Overall, in the higher water temperature, the higher survival rate comes out and in the lower rearing density, the higher the survival rate does. In a study on feed efficiency, weight gain (WG) increased significantly as water temperature increased, and weight gain according to rearing density significantly decreased as rearing density increased. The growth rate of L. vannamei was faster when the water temperature was higher (water temperature 31℃) under low salinity conditions. In addition, in the evaluation of the growth rate according to the rearing density, it was confirmed that the growth rate was accelerated at a low rearinging density. It is believed that the results of this study will be usefully applied to the determination of the optimal rearinging density and breeding water temperature of L. vannamei in low salinity condition.