• 한국어류학회지
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• 제30권1호
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• pp.1-8
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• 2018

스트레스를 유발하는 환경적인 요소 중, 염분의 변화는 어류의 성장과 생존에 있어 많은 영향을 미친다. 본 연구에서는 한국의 양식대상 어종인 넙치(P. olivaceus)를 대상으로 넙치양식에 있어 적정 염분범위를 구명하기 위하여 각 염분별(25, 20, 15 psu 및 10 psu) 조건을 통해 24시간 및 48시간 동안 노출시킨 후, 혈액생리학적 분석 및 HSP70 mRNA 발현을 조사하였다. 혈액학적 분석에서 hematocrit (Ht) 및 hemoglobin (Hb), 혈장 코티졸 (cortisol) 및 글루코스 (glucose)의 변화, aspartate aminotransferase (AST) 및 alanine aminotransferase (ALT), $Na^+$, $K^+$, $Cl^-$, $NH_3$, 삼투질농도(osmolality) 및 총 단백질(total protein, TP)는 저염분 조건인 10 psu 및 15 psu에서 다른 염분별 실험구에 비해 대부분의 항목에서 유의적인 차이를 보였다. 혈장 내 SOD (superoxide dismutase) 및 CAT(catalase) 활성에서도 마찬가지로 대조구인 자연해수의 조건보다 저염분(10 psu 및 15 psu)으로 갈수록 증가하는 경향을 보였다. 스트레스성 단백질로 알려진 HSP 70 mRNA 발현에서도 대조구보다 저염분에서 유의적인 차이를 확인하였다. 이러한 결과로, 염분변화에 의한 스트레스가 넙치의 생체방어메커니즘과 항상성 유지를 위한 결과로 혈액학적 반응, 호르몬의 분비 및 단백질 발현의 증가가 나타나는 것으로 여겨지며, 이를 바탕으로 저염분에 대비한 넙치양식에 있어 기초적인 자료로 활용될 것이 기대된다.

• 미생물학회지
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• 제29권5호
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• pp.329-338
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• 1991

From July 1985 to December 1986, 28 variables of phycal-chemical factors, bacteria and heterotrophic activity were investigated 17 times at 3 stations in the estuary of Naktong River and the influences of environmental factors to bacterial population and heterotrophic activity were analyzed through multiple regression. The results of multiple regression were as follows. At station 1, total bacteria and heterotrophic bacteria(Z-25) could explain 57% of the variation of maximum uptake velocity for glucose and 54% of turnover time for glucose was explained by total coliform bacteria and MBOD, Sixty four percent of the variation of Kt+SN was accounted for salinity, MBOD-N and inorganic phosphate. Turnover rate for acetate was also accounted for the change of MBOD-P by 56%. At station 2 maximum uptake velocity for glucose depends on MBOD-N by 81%; turnover time on bacteria by 50%; Kt+Sn on avilable nutrient by 61%. More than 50% of maximum uptake velocity and turnover time for glucose were influenced by bacteria and that of Kt+Sn by the change of nutrient in the surface water of station 3. In the bottom water of station 3, the change of maximumuptake velocity, turnover time and Kt+Sn for glucose was controlled by total bacteria and available nutrient, bacteria, the change of nutrient salts respectively. On the whole, more than 50% of maximum uptake velocity and turnover time for glucose could be due to the change in the number of bacetria and the value of Kt+Sn was affected by the change of nutrient salts. Turnover rate for acetate was controlled by available phosphate at station 1 and by bacteria at station 2 and 3, which showed a distinct difference between the environmental factors which govern the rate of glucose and acetate uptake in the Naktong esturine ecosystem. And bacterial communities were controlled by available nutrients at station 1, by nutrient salts and salinity at station 2 and in the surface water of station 3 and by salinity in the bottom water of station 3.

• 한국농공학회논문집
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• 제60권3호
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• pp.113-121
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• 2018

The objectives of the research were 1) to develop the low-cost and high efficient desalination system to treat brackish water having high salt contents for irrigation at greenhouses near coast, and 2) to monitor and assess the effects of the brackish water desalination system on soil environment and growth in squash greenhouse cultivation area. The monitoring site was one of the squash greenhouse cultivation farm at Choengam-ri, Jinsang-myun, Gwangyang-si, Jeonnam-Do Monitoring results for groundwater irrigation water quality, and salinity showed a remarkable difference between control and treatment group. The salinity of soil at treatment group was less than at control group. While, the system made possible to increase the squash quantity from 4.7 ea to 6.3 ea at each and the average weight of the harvested squash was increased from 277.2 g to 295.1 g. The applied brackish water desalination system may be appled to reclaim sea or brackish irrigated area as alternative water resources, although long-term monitoring is needed to get more representative results at different level of salinity.

• 생태와환경
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• 제46권2호
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• pp.205-214
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• 2013

영산강 하구에서 담수 유입이 부유생태와 수질에 미치는 영향을 파악하기 위해 국가해양환경측정망 장기자료(1999~2008년)인 클로로필 a와 수질 항목들에 대한 계절적, 공간적 변화와 장기변동 추세를 분석하였다. 분석결과, 여름철 (8월) 영산강 방조제 인접정점의 염분은 조사기간 중 가장 낮은 분포를 보였고, 영양염류와 클로로필 a는 전반적으로 높은 분포를 나타냈다. 영산강 담수유입의 지시인자인 표-저층의 염분차 (${\Delta}salinity$)와 영양염류, 클로로필 a는 유의한 양의 상관성을 나타냈으나, 지난 10년동안 담수 방류량은 감소하는 추세를 보였고, 영양염류, 클로로필 a는 전반적으로 증가하는 경향을 나타냈다. 이러한 결과는 영산강 하구 해역 영양염의 공급원이 담수유입뿐만 아니라 인근 지역의 발달에 따른 점오염원 증가 등의 추가적인 요인이 존재할 가능성을 제시한다. 따라서 영산강 하구 주변 해역의 부영양화 방지를 위해서는 영산강 방조제의 방류와 연관한 수질개선방안 마련과 더불어 인근 지역의 점 오염원 파악 및 관리가 병행되어야 할 것으로 사료된다.

• 한국물환경학회지
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• 제33권4호
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• pp.481-486
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• 2017

This paper aims to evaluate the characteristics of direct and indirect effluents'toxicity level and difference between two test durations (24 h and 48 h) of test method. The proportion of the indirect effluent samples which exceeded the ecotoxicity permit limitations (TU 1 or TU 2) showed more than 2 times higher than that of direct effluent samples. However, effluent toxicity of Wastewater Treatment Plants (WTPs) indicated less than TU 1 regardless of influent toxicity. From this results, treatment process was thought to have a good efficiency. WTP Salinity was very similar between influent and effluent. This trend could be reconfirmed by the component ratio of ion concentration between them and $Na^+$, $SO_4^{2-}$, $C^-$ lions which have a greater percentage than other ions. In addition, in case of high salinity, toxicity value also showed high level. To judge from above results, indirect effluents which were exempted from application of ecotoxicity standards, may need a new effluent limitations regardless of the treatment efficiency of WTP. According to circumstances, effective countermeasure may need to restrain the discharge of salinity-contained effluents which came from indirect-effluent factories. Test duration comparative study indicated that 48 h results were higher toxicity (exceeding rate of ecotoxicity criteria) than 24 h by the 5 to 5.4 percentage. 24 h test duration seemed to be useful in case of rapid detection, whereas 48 h test method could be applied for reinforcement of ecotoxicity regulatory system.

• Ocean and Polar Research
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• 제31권4호
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• pp.339-347
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• 2009

It is possible to obtain accurate temperature and salinity profiles of the oceans using a SBE 911plus CTD and accompanying data conversion packages. To obtain highly accurate results, CTD data needs to be carefully processed in addition to proper and regular maintenance of the CTD itself. Since the manufacturer of the CTD provides tools that are necessary for post processing, it is possible to conduct proper processing without too much effort. Some users, however, are not familiar with all of the processes and inadvertently ignore some of these processes at the expense of data quality. To draw attention to these and other similar issues, we show how it is possible to improve data quality by utilizing a few extra processes to the standard or default data process procedures with CTD data obtained from the equatorial Eastern Pacific between 2001 and 2005, and 2007. One easy step that is often ignored in the standard data process procedure is "wild edit", which removes abnormal values from the raw data. If those abnormal values are not removed, the abnormality could spread vertically during subsequent processes and produce abnormal salinity in a range much wider than that of the raw data. To remove spikes in salinity profiles the "align CTD" procedure must be carried out not with the default values included in the data processing software but with a proper time constant. Only when "cell thermal mass" correction is conducted with optimal parameters, we can reduce the difference between upcast and downcast, and obtain results that can satisfy the nominal accuracy of the CTD.

• 한국식생활문화학회지
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• 제29권3호
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• pp.286-297
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• 2014

This study was conducted to evaluate the growth of lactic acid bacteria and quality characteristics of Baechu kimchi prepared with four types of salt (Solar salt, Flower salt, Hanju salt, and Roasted salt) at two different concentrations (10, 15%) during storage. The quality characteristics of kimchi were examined by investigating acid production, growth of lactic acid bacteria, sensory properties, salinity, texture, and color characteristics. Baechu kimchi was fermented for 18 days at $10^{\circ}C$. The pH and total acidity did not change during storage according to type and concentration of salt. Growth of lactic acid bacteria was not affected by type of salt, whereas it was inhibited at 15% salt concentration after 9 days of fermentation. In the quantitative descriptive analysis of sensory properties, kimchi prepared with 10% salt showed significantly higher scores in term of overall acceptability (p<0.05). Meanwhile, there was no significant difference by type of salt. For texture characteristics, hardness of kimchi prepared with 10% salt was significantly higher than that with 20% salt. For color characteristics, L value (brightness) and b values (yellowness) of kimchi prepared with 10% salt increased during fermentation, whereas a value (redness) did not change by type and concentration of salt. The results of this study show that there were no considerable differences in quality characteristics of Baechu kimchi prepared with various types and concentrations of salt. However, Solar salt resulted in more favorable sensory properties and salinity of kimchi than any other types. Further, kimchi prepared with 10% salt showed significantly higher scores in terms of overall acceptability, growth of lactic acid bacteria, salinity, texture, and color characteristics.

• 한국해양환경ㆍ에너지학회지
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• 제6권2호
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• pp.28-37
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• 2003

평년도 보다 많은 강우량을 기록한 2002년 7월 20일과 25일 및 9월 3일에 담수 방류에 따른 목포 주변 해역의 수질분포 특성을 파악하고자 영산강 하구 둑을 기점으로 목포 주변 해역 25개 정점의 표층과 저층의 해수를 채수하여 염분, 용존산소, 암모니아질소, 질산질소, 총질소, 인산인, 총인, SS, COD 및 Chlorophyll-a의 분포를 조사하였다. 염분과 용존산소는 현장에서 조사되었고 그 외 수질 인자는 해양환경공정시험법에 따라서 측정하였다. 조사결과, 고화도 입구를 기점으로 염분분포와 55분포가 확연한 차이를 보이고 있어 내부해역과 외부해역으로 구분하여 기술하였다. 지점별 층별 염분과 55 분포와 각 형태의 영양염의 분포 및 Chlorophyll-a의 분포 특성 및 염분과 각 수질인자들 간의 관계로부터 검토한 결과 목포항의 입구인 고화도와 목포해양대 사이를 기점으로 한 내부 해역에서는 영산강에서 방류되는 담수의 영향이 크게 나타나고 있는 반면에 외부 해역에서는 일반적인 연안에서 볼 수 있는 수질 분포를 보이고 있었다.

• 한국수산과학회지
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• 제54권5호
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• pp.761-768
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• 2021

This study was carried out to identify an effective method to acclimate low-salinity (4 psu) bred Litopenaeus vannamei (mean body weight 16±3.3 g) to sea water. The fast acclimation group (FA) was directly exposed to filtered sea water (32 psu) while the slow acclimation group (SA) was exposed to a slow increase in salinity. Shrimps were sampled at 0, 1, 3, 6, 12, 24 and 48 h for plasma analyses. The plasma components between experimental groups did not show significant differences. The hemolymph osmolality (HO) in FA increased significantly after 1 h (P<0.05), while in SA it started to increase slowly only at 24 h and reached a similar level to that of FA at 48 h. The levels of Na⁺ and Mg²⁺ ions were significantly different between the two treatments (P<0.05), but there was no significant difference in Ca²⁺ ion levels. We found that the different methods of acclimation of L. vannamei to sea water do not affect the plasma components significantly, but lead to changes in the HO and ion levels, it is considerable to acclimate gradually for at least two days.

• 한국식생활문화학회지
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• 제26권4호
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• pp.394-399
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• 2011

This study was conducted to investigate the effect of Nelumbo nucifera G. (NN) powder on cookie quality characteristics. The cookies were made with various NN powder levels (1, 3, and 5%). Crude fiber, crude ash, and the Mg contents of cookies with added NN powder were higher in concentration than those of the control group. Salinity of NN-powder added groups was not significantly different when it was compared with the control group's salinity. No significant difference among the groups were observed for specific volume, but the width determined by water content in the dough decreased as the amount of added NN powder increased. The L-value of the cookies was significantly larger than that of the control group. The a- and b-values were the highest for the 5% substituted NN flour. According to the sensory evaluation of the cookies, scores for color, flavor, and texture increased with increasing amounts of added NN powder. The overall acceptance of the 3% NN added cookies was greater than that of the 1 and 5% cookies.