• Korean Journal of Poultry Science
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• v.33 no.2
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• pp.159-164
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• 2006

To investigate the effects of salt contents in diet and water on the growth of broiler chicks, 288 heads of Hubbards strain chicks, were fed with com-soybean meal diets containing 0, 0.25, 0.5, 0.75 1.0, 2.0, 3.0, or 4.0% salt from 1d to l4d posthatching. And 180 chicks were also supplemented with salt to their water at 0, 0.1, 0.2, 0.5 or 1.0%. Feed intake and weight gain tended to decrease as the salt levels in diets increased and those were the lowest in 4% group as 481 g and 168 g, however, mortality was the highest in 4% group as 75.0%. As for the salt levels in water, feed intake and weight gain were low as 427 g and 162 g in 1% group, while mortality was 77.8%. Salt poisoning chicks were shown with thirsty, appetite deficiency, rising impossibility, sleepiness, or convulsions, and in autopsy, were shown with ascites, hydropericardium, cardiac hypertrophy, hemorrhage of eyelid, hemorrhage of trachea, hemorrhage of intestine, etc. Conclusively, salt content above 4% in diet or 1% in water could reduce the performance in broiler chicks.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.12 no.4
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• pp.293-296
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• 1979

The effects of temperature and salinity on tile rates of ammonia and amino nitrogen excretion, and oxygen consumption were measured for Crassostrea gigas. There was variability with temperature and salinity changes in both the rates of nitrogen excretion and the proportionality between ,ammonia and amino acids in the excreta, and also in the rates of oxygen consumption. Rates of nitrogen excretion and oxygen consumption were markedly decreased with increase in salinity, especially at high salinity-high temperature, whereas at low salinity-high temperature condition they were significantly increased. These changes are considered as the responses of physiological tolerances to the high temperature stress and the results of the metabolic temperature compensation at the low salinity-high temperature condition. Most of nitrogenous excretory products was ammonia, and large amounts of amino-nitrogen was excreted, and especially the rate of amino-nitrogen excretion was dominant at $32.5\%_{\circ}-22^{\circ}C$. The amounts of amino-nitrogen excreted by animals were decreased in the medium of high salinity and increased in the medium of low salinity through the experimental temperature. The atomic ratios of oxygen consumed to ammonia-nitrogen excreted (O: N ratio) was low at the low temperature $(15^{\circ}C)$, and was high at $22^{\circ}$ and $29^{\circ}C$ in the medium of 32.5 and $37.5\%_{\circ}$ but low in the low salinity $27.5\%_{\circ}$.

• Geophysics and Geophysical Exploration
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• v.8 no.1
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• pp.78-85
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• 2005

This study, combining geophysical and environmental approaches, was undertaken to investigate the causes of secondary salinity in the Goondoola basin, in southwestern Queensland. Airborne radiometric, electromagnetic and ground electromagnetic datasets were acquired, along with data on soils and subsurface materials and groundwater. Relationships established between radiometric, elevation data, and measured material properties allowed us to generate predictive maps of surface materials and recharge potential. Greatest recharge to the groundwater is predicted to occur on the weathered bedrock rises surrounding the basin. Electromagnetic data (airborne, ground, and downhote), used in conjunction with soil and drillhole measurements, were used to quantify regolith salt store and to define the subsurface architecture. Conductivity measurements reflect soil salt distribution. However, deeper in the regolith, where the salt content is relatively constant, the AEM signal is influenced by changes in porosity or material type. This allowed the lateral distribution of bedrock weathering zones to be mapped. Salinisation in this area occurs because of local-andintermediate-scale processes, controlled strongly by regolith architecture. The present surface outbreak is the result of evaporative concentration above shallow saline groundwater, discharging at break of slope. The integration of surficial and subsurface datasets allowed the identification of similar landscape settings that are most at risk of developing salinity with groundwater rise. This information is now being used by local land managers to refine management choices that prevent excess recharge and further salt mobilisation.

• Korean Journal of Remote Sensing
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• v.37 no.5_2
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• pp.1307-1315
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• 2021

The Changjiang Diluted Water (CDW) spreads over the East China Sea every summer and significantly affects the sea surface salinity changes in the seas around Jeju Island and the southern coast of Korea peninsula. Sometimes its effect extends to the eastern coast of Korea peninsula through the Korea Strait. Specifically, the CDW has a significant impact on marine physics and ecology and causes damage to fisheries and aquaculture. However, due to the limited field surveys, continuous observation of the CDW in the East China Sea is practically difficult. Many studies have been conducted using satellite measurements to monitor CDW distribution in near-real time. In this study, an algorithm for estimating Sea Surface Salinity (SSS) in the East China Sea was developed using the Geostationary Ocean Color Imager (GOCI). The Multilayer Perceptron Neural Network (MPNN) method was employed for developing an algorithm, and Soil Moisture Active Passive (SMAP) SSS data was selected for the output. In the previous study, an algorithm for estimating SSS using GOCI was trained by 2016 observation data. By comparison, the train data period was extended from 2015 to 2020 to improve the algorithm performance. The validation results with the National Institute of Fisheries Science (NIFS) serial oceanographic observation data from 2011 to 2019 show 0.61 of coefficient of determination (R²) and 1.08 psu of Root Mean Square Errors (RMSE). This study was carried out to develop an algorithm for monitoring the surface salinity of the East China Sea using GOCI and is expected to contribute to the development of the algorithm for estimating SSS by using GOCI-II.

• Proceedings of the Korean Aquaculture Society Conference
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• 2006.05a
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• pp.373-374
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• 2006

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.129.2-130
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• 1998

• The Korean Journal of Malacology
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• v.30 no.2
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• pp.101-106
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• 2014

Clearance rate and feeding of surf clam, Mactra veneriformis were determined for 5 different water temperature regime (5, 10, 15, 20, $25^{\circ}C$) and salinity regime (8, 14, 20, 26, 32 ‰) with small group ($86.62{\pm}7.10mm$ in shell length) and large group ($147.99{\pm}10.83mm$ in shell length). Clearance rate and feeding increased with water temperature up to $20^{\circ}C$, but rapidly decreased at $25^{\circ}C$. The minimal clearance rate and feedign was recorded at $5^{\circ}C$. surf clam showed low clearance rate and feeding at low salinity (below 20 ‰) and maximum values at high salinity (26-32 ‰).

• Proceedings of the Korea Water Resources Association Conference
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• 2009.05a
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• pp.608-612
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• 2009

본 연구에서는 하수재이용에 따른 토양에서의 염분변화를 추정하기 위하여 SWAP(Soil-Water-Atmosphere-Plant) 모형을 선정하여 경기도 화성시 수원환경사업소 인근에 위치한 병점지구를 대상으로 모형의 적용성을 분석하였다. 실험에 사용한 관개용수는 1) 지하수(TR#1), 2) 하수처리장 방류수+여과+UV (TR#3)로 분류하여 실험에 사용하였다. 영농기간 동안 논으로 유입되는 총 유입수는 $1,724.2^{\sim}1,733.7$ mm 범위였으며, 이 중 약 64%가 강우에 의해 공급되었고, 나머지는 관개에 의하여 유입되었다. 유입관개수의 EC는 지하수 관개수인 TR#1이 다른 처리구에 비해 작았고, TR#3의 경우 $0.442{\sim}0.698$ dS/cm의 범위를 보였다. 모형의 보정과 검정을 위해서 대상지구에 FDR(Frequency Domain Reflection)을 설치하여 토양수분함유량과 염분농도를 토심에 따라 일단위로 모니터링 하였다. 토양함수량의 보정기간 중 토심별(50, 100, 140 cm) RMSE는 TR#1에서 $0.001^{\sim}0.002$ $cm^3cm^{-3}$, TR#3에서 $0.002^{\sim}0.006$ $cm^3cm^{-3}$으로 나타났으며, 검정기간 중 토심별 RMSE는 TR#1에서 $0.003^{\sim}0.064$ $cm^3cm^{-3}$, TR#3에서 0.001$cm^3cm^{-3}$로 나타났다. 토양염분의 보정기간 중 토심별 RMSE는 TR#1에서 $0.001^{\sim}0.023{\times}10^{-3}$ dS $m^{-1}$, TR#3에서 $0.028^{\sim}0.045{\times}10^{-3}$ dS$m^{-1}$로 나타났으며, 검정기간의 토심별 RMSE는 TR#1에서 $0.018^{\sim}0.037{\times}10^{-3}$ dS$m^{-1}$, TR#3에서 $0.004^{\sim}0.014{\times}10^{-3}$ dS$m^{-1}$로 적용성이 있는 것으로 나타났다.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.119-126
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• 2021

In this study, the variability in paralytic shellfish poisoning (PSP) by the toxic dinoflagellate Alexandrium catenella (Group I) was analyzed under a variety of water temperatures and salinities. This dinoflagellate experienced optimum growth at temperatures and salinities of 20~30℃ and 20~30 psu, respectively. These findings indicate that A. catenella is an eurythermal and euryhaline organism. High toxin contents and toxicities were observed at low temperatures (10 and 15℃), where they were associated with low growth rates; salinity did not have any significant impact on toxicity parameters. Therefore, it is likely that A. catenaella contributes to the rapid intoxication of commercial bivalve when temperatures are ≤15℃. To better estimate PSP caused by A. catenalla, we suggest that the influence of various environmental factors controlling PSP should persist with other A. catenella stains and commercial bivalves.

• Korean Journal of Ecology and Environment
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• v.39 no.3 s.117
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• pp.352-365
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• 2006

In order to evaluate the change of aquatic environment in the reclaimed Hwaong Reservoir, situated in the early stage after construction, this study was conducted to measure the change of precipitation, temperature, and salinity from June 2002 to January 2006. The range and mean of temperature was $-0.7{\sim}33.4^{\circ}C$ and $13.6^{\circ}C$, respectively. Temperature of upstream part rapidly changed during the transitional period; from spring to summer and from fall to winter. It showed abrupt decrease with high discharge from the streams temporarily. While, hypolimnetic temperature of upstream happened to be somewhat higher than that of surface or downstream. The range and mean of salinity was 0.3${\sim}$32.3 psu and 25.3 psu, respectively. Vertical difference of salinity was marked, and the change in the surface water was much higher than middle or bottom layers. It showed the marked difference at all stations, except for the bottom layer of upstream into which Namyang Stream flows, indicating that vertical gradient of salinity is strongly sustained in the reservoir. Salinity was changed markedly during the storm period (June${\sim}$October), and freshwater with low salinity was expanded from upstream to downstream along the surface layer. The surface of the reservoir was totally covered by the stream discharged water with a large amount of silt and low salinity during this period. The difference of temperature and salinity between the surface and bottom layer ranged $-10.6{\sim}9.7^{\circ}C$ and $-27.1{\sim}30.0$ psu, respectively. The big difference of salinity appeared with a large discharge of freshwater from the streams or large input of seawater through the gate. Salinity was negatively correlated with temperature, indicating the influence of monsoon storm events on the salinity under the whole watershed scale of this brackish reclaimed reservoir.