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

• Journal of Aquaculture
• /
• v.20 no.4
• /
• pp.226-231
• /
• 2007

We investigated survival and osmolarity, oxygen consumption, amonia extetion and filtration rates associated with physiological responses of the tunicate Halocynthia roretzi salinity changes. Acclimation times for osmolatity in different salinities took $20{\sim}26$ hours in 60% SW (19.8 psu) and $20{\sim}25$ hours in 80% SW (26.4 psu), while their times took $7{\sim}8$ hours in 110% SW (36.3 psu). Accordingly, acclimation times for high salinities were faster than those for low salinities. Survival (%) was more than 80% at salinity over 26.4 psu, and 6 $days-LS_{50}$ was 25.4 psu. physiological responses such as oxygen consumption, amonia excretion and filtration rates of H. roretzi showed more clear reactions in the longer exposure period (four days after exposure) than that in the beginning of the exposure. To sum up the results, the tunicate might be stressed from the beginning of the exposure in low salinity.

• Proceedings of the Korea Water Resources Association Conference
• /
• 2010.05a
• /
• pp.1500-1504
• /
• 2010

본 연구에서는 EFDC(Environmental Fluid Dynamics Code) 모형을 이용하여 이원 담수화호의 염분분포를 모의하였다. SMS(Surface Water Modeling System) 모형을 이용하여 담수호에 대한 격자망을 구성하였다. 격자체계는 직교좌표계를 사용하였으며, 전체 2,620개의 유효계산격자를 구성하여 모형에 적용하였다. 수위 및 유량에 대한 경계조건은 기상자료와 배수갑문 운용자료를 통해 구축하였으며, 초기조건은 수위 실측자료를 이용하였다. 담수호의 염분모의를 위한 모형의 경계 조건은 호내에 위치한 5개소의 실측자료를 이용하였으며, 유역에서의 유입수염분농도는 0.2 ppt, 방조제 외측으로부터의 유입수 염분농도는 해수조건(30 ppt)을 적용하였다. 염분분포 모의를 위해 2006년부터 2008년까지 3년동안의 염분농도 실측자료를 이용하여 보정과 검정을 실시한 결과, 대상 지역에 대해 EFDC 모형의 적용성이 있는 것으로 나타났다.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.34 no.1
• /
• pp.51-56
• /
• 2001

Changes of gill tissue and body composition of grey mullet (Mugil cephalus) and Nile tilapia (Oreochromis niloticus) by the manipulation of salinity were observed in a recirculating rearing system. Salinity was increased from $0\%_{\circ}$ to $33\%_{\circ}$for 1 day and remained far 15days, thereafter salinity was decreased from $33\%_{\circ}$ to $0\%_{\circ{$ for 1 day and remained for other 15 days. Any morphological differences of gill lamella in grey mullet were not observed in seawater and freshwater. However, on day 2 in exposure to seawater, Nile tilapia showed the edema and bloodclot in gill lamella. In the case of grey mullet, mitochondria and tubular system of chloride cell were more densely packed according to the salinity increase. The whole body of grey mullet showed no significant differences in moisture content during experimental period. However, moisture content in whole body of the Nile tilapia was signincantly decreased when exposed to seawater. Protein content in whole body of grey mullet showed no significant difference between beginning and day 15 of the experiment.

• Journal of the Korean Data and Information Science Society
• /
• v.28 no.4
• /
• pp.811-818
• /
• 2017

Environmental tests are used to verify a equipment that can withstand the rigors of harsh environments. In case of military products for export, the tests have to be based on the climatic data of the world. However, if the climatic data of the world is used for domestic military products, it may cause an increase in manufacture price. There is currently no climatic data that can be used as criteria for the tests in the Korean peninsula and coastal seas. Therefore, this paper suggests a water temperature and a salinity guidelines of salt fog tests for military products used in the area. As a result, we present water temperature and salinity information that is extreme and FOO of the Korean coastal seas.

• Journal of Marine Life Science
• /
• v.7 no.2
• /
• pp.205-212
• /
• 2022

Transport is essential in the farming process of farmed fish and is one of the physical stress factors such as sorting. The effect of water temperature and anesthesia during low salinity transport was confirmed. In the experimental group, the water temperature was set to 20℃ (natural water temperature, NWT), 15℃ (cooling water temperature, CWT) respectively, in water with a salinity concentration of 35‰, 15‰ and an anesthetic (anesthesia, Anes., Sigma USA) was diluted and mixed to 50 ppm. A styrofoam box (66×42×20 cm) was used as a transport container, and 8 flounder were accommodated and transported in a plastic bag injected with 3 ℓ of seawater and liquid oxygen. As a result of the study, the concentration of cortisol before transport increased significantly from 2.4±0.1 ng ml^-1 in the experimental groups except for the CWT+35‰ group (16.7±12.8 ng ml-1). The K⁺ concentration slightly increased from 3.1±0.0 mEq l^-1 before transport to 4.5±1.1 mEq l^-1 in the NWT+15‰ group, showing no difference, and significantly increased in all other experimental groups. There was no effect on changes in blood characteristics, and water temperature and anesthetic had a negative effect on osmotic control due to stress. AST and ALT were not affected.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.18 no.4
• /
• pp.178-185
• /
• 2013

We measured salinity and $^{222}Rn$ concentration to explore submarine spring along the coastal areas (Mundongri, Icheon-ri, Jukseong-ri, Daebyeon-ri, Yeonhwa-ri, and Dadae-po) including Ilkwang Bay of Busan Metropolitan City in 2009 and 2010. Before field observation, we selected the potential and possible locations of submarine spring based on the lineament distribution and rose diagram analysis. Salinity and radon concentration were measured within the 1~2 km from the coastal lines. Radon activity decreased gradually from onshore to offshore. Vertical profiles of salinity at some stations showed lateral transport of water mass characterized by low salinity. Vertical profiles of salinity in the Ilkwang Bay, which is a unique bay in the south-eastern coastal area of Busan Metropolitan City, also showed the occurrence of low salinity in the bottom seawater. Our results suggest the possible occurrence of submarine discharge of fresh groundwater in the coastal areas around Busan Metropolitan City. In the future, intensive research should be conducted for the exploration methods of submarine spring as well for the possible utility of submarine groundwater as alternative water resources.

• Korean Journal of Ichthyology
• /
• v.21 no.3
• /
• pp.158-166
• /
• 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 Korea Water Resources Association Conference
• /
• 2019.05a
• /
• pp.235-235
• /
• 2019

감조하천 구간에서의 수면경사 및 유속분포 등 흐름특성은 조석의 영향으로 자연하천과 달리 매우 복잡하고 다양한 형태를 보이고 있다. 또한 하류에서 상류로 조류 유입시 해침으로 인한 염분도 상승으로 수서생물은 담수종에서 기수종 및 해수종으로 천이되고 있다. 섬진강 하구의 대표적인 수서생물인 재첩은 염분도 상승에 따라 폐각을 닫고 모래층으로 이동하는 특성을 보이고 있다. 이러한 관점에서 본 연구는 감조하천 구간에서의 취수장의 취수 규모에 따른 염분도 변화특성을 살펴보고, 하구 수서생물생활환경에 적합한 염분도를 유지할 수 있는 합리적인 취수장 운영방안을 마련하는 데 있다. 이를 위해 과거 취수장 상류의 유출량에 따른 취수규모별 하구 염분도 변화 특성을 분석하였다.

• KSCE Journal of Civil and Environmental Engineering Research
• /
• v.41 no.5
• /
• pp.485-492
• /
• 2021

This study focused on safety aspects surrounding energy consumption in the seawater desalination process in the Daesan Industrial Complex located on the West Sea coast. The safety index for energy consumption was evaluated under different salinities and temperatures of the incoming seawater. Temperature and salinity input data for the 1997-2018 period were obtained from the Marine Environment Information System, and the power required for reverse osmosis (RO) was applied to the program as per the data provided by the RO membrane manufacturer (Q-Plus v3.0). Notably, reasonable energy consumption guidelines were proposed during the design of the desalination facilities; in this regard, the desalination process required approximately 2.10-2.90 kWh/m³ electrical power. Moreover, the energy safety based on 95 % was estimated to be 2.80 kWh/m³ when the desalination facility was operated.