• 제목/요약/키워드: Low salinity

검색결과 835건 처리시간 0.033초

섬진강 하구역에서 염분경사에 따른 동${\cdot}$식물플랑크톤의 현존량 및 종조성 (Biomass and Species Composition of Phytoplankton and Zooplankton along the Salinity Gradients in the Seomjin River Estuary)

  • 이평강;박철;문창호;박미옥;권기영
    • 한국해양학회지:바다
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    • 제6권2호
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    • pp.93-102
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    • 2001
  • 1999년 3월, 7월, 9월 및 11월에 섬진강 하구역에서 염분경사에 따른 식물플랑크톤과 동물플랑크톤의 현존량과종 조성의 변화를 조사하였다. 조사 정점은 지리적 위치보다는 각 조사시마다 표층 염분을 현장에서 측정하여 결정하였다. 식물플랑크톤은 총 96종이 동정되었으며, 그 중 돌말류가 60종으로 전 조사해역에서 출현하였다. 저염분역에서는 녹조류의 종수가 비교적 높았으며 고염분역으로 갈수록 와편모조류의 종수가 증가하였다. 월별 식물플랑크톤 현존량의 평균 값은 $183{\sim}833$cells/m의 범위로 11월에는 5${\sim}$15 psu 염분역에서 Skeletonema costatum의 bloom이 발생하였으며 초저염분역에서 현존량의 급격한 감소는 3월에 관찰되었다. 염분이 8.1 psu 이하의 분포를 보였던 강우기인 7월에 대부분의 조사해역에서 녹조류가 우점하였다. Chroomonas spp.는 3월과 9월에 높게 우점하였으며 고염분역으로 갈수록 현존량이 증가하였다. 동물플랑크톤은 3회의 조사에서 총 83개의 분류군이 검색되었고, 이중해산 분류군은 총 72개로 요각류가 34개 분류군을 차지하고 있었으며 담수 분류군은 총 11개로 수서 곤충류가 대부분을 차지하였다. 동물플랑크톤 종 조성은 해수의 유입에 의해 크게 의존하는 것으로 나타났으며 담수종이 출현하는 염분 한계는 시기적으로 달랐는데, 7월에는 8.1 psu 이하에서 , 9월에는 4.7 psu 이하에서 , 11월에는 0.2 psu 이하에서만 출현하였다. 하구역 염분 변화에 따른 동물플랑크톤 출현 양상의 특징은 풍수기에서 갈수기로 진행되면서다소 변화하는 양상을 보이지만 대체로 중간 정도의 염분 구역에서 출현 종과 개체수가 감소하는 경향을 보였다.

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염분농도에 따른 넙치 (Paralichthys olivaceus)의 성장호르몬, 프로락틴 및 수용체 유전자의 발현변화 (Gene Expression Levels of Growth Hormone, Prolactin and Their Receptors of Olive Flounder Paralichthys olivaceus by Salinity Changes)

  • 조영민;신지혜;손영창
    • 한국수산과학회지
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    • 제39권4호
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    • pp.326-332
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    • 2006
  • To investigate the effects of environmental salinity on the expression of the genes for growth hormone (GH) and prolactin (PRL) in the pituitary, and their receptors (GHR, PRLR) In the kidney, intestine, and gills in teleosts, we acclimated juvenile olive flounders (Paralichthys olivaceus) to different salinities (5, 15, 25, or 32 psu) for 3 days and examined their mRNA levels using the reverse transcription-polymerase chain reaction (RT-PCR). In the fish adapted to low salinity, the PRL mRNA levels in the pituitary were elevated dramatically, whereas the GH mRNA levels did not differ significantly. PRLR mRNA increased significantly in fish exposed to low salinity, whereas GHR mRNA levels did not differ. These results suggest that PRL is an important hormone for flounders that are acclimated to brackish water and it may control ion homeostasis with PRLR in the osmoregulatory organs.

저염 장류에서 증식하는 산막 효모에 길항 작용을 갖는 Bacillus 균주의 분리 (Isolation and Identification of Bacillus Strains with Antagonistic Properties against Film-forming Yeasts Overgrown in Low Salted Soybean Pastes)

  • 전새봄;류명선;김용상;조승화;정도연;엄태붕
    • 미생물학회지
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    • 제49권3호
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    • pp.286-291
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    • 2013
  • 한국인의 저염 섭취 필요성에 부응하기 위해 14% (w/w) 염도의 된장 대신 8% (w/w) 저염 된장을 제조하였다. 숙성 후 8% 저염 된장 시료들은 14% 염 된장과 달리 모두 산막을 형성하였고, 이 산막 형성균들을 동정한 결과 8종 모두 효모인 Pichia kudriavzevii에 속하였다. 장류 고유한 풍미를 유지하기 위해 발효 특성이 우수한 11종의 Bacillus 균들을 전통 장류에서 분리했고, 이들의 생화학적 특성 및 16S rRNA 염기 서열 분석 결과 B. subtilis, B. licheniformis, B. methylotrophicus로 동정되었다. 이 균주들은 8종의 산막 효모에 대해 증식 억제 능력을 보였으며, 항균 계면활성제인 lichenysin 또는 surfactin 유전자들을 함유하고 있었다.

서울 일부 지역 어린이집 조리종사자 대상 나트륨 저감화 교육 효과 - 자기 재평가와 의식증가를 위한 교육 결과 - (The Effectiveness of Na Reduction Program for Cook in Child-care Center - Focus on Self-reevaluation and Strengthen Consciousness -)

  • 신혜원;이영미
    • 대한지역사회영양학회지
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    • 제19권5호
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    • pp.425-435
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    • 2014
  • Objectives: The purpose of this study was to develop a Na-reduction education program and apply it for cooks who prepare meals in day-care centers. To development of the program was based on increasing the self-awareness of salinity, eating behaviors and enforcing skills of low-Na cooking. Methods: The study was carried out from April to October in 2013, fifty five cooks participated in this program. The Na reduction program composed of 4 sessions of education which included a 90-minute lecture and self-reevaluation of personal salt-sensitivity degree and three low Na recipe cooking classes. In order to measure the effectiveness of the program, the pretest and posttest of salinity of the soups provided by day care centers was conducted at registration and 5 month after the program with the same menu. Results: After the conduct of the program, salimeter using rate was increased from 8.2% to 94.6% after the program and the other measuring instruments using rate was gradually increased. We observed that the score on eating behaviors increased 1.51 points from 38.80 to 40.31 after the intervention program (p < 0.001). Further, increased knowledge and skill provided by the intervention program resulted in improved Na-reduction cooking capability. According to the results from analyzing the soup salinity, the salinity in watery soup was significant reduced from 0.556 to 0.449 0.107 and soybean-paste soup was significant reduced from 0.669 to 0.551 after the intervention program (p < 0.001). Conclusions: As the result of fact, the intervention programs that was based on self-reevaluation, to enforce practical skill and consciousness was effective to serve low sodium menu at day care centers.

국내산 저염분 양식 흰다리새우 유래의 슈와넬라의 병원성 세균으로의 특성 (Shewanellasp., A Potential Pathogen of White Leg Shrimp Cultured in Low Salinity Water in Korea)

  • 전진우
    • 현장농수산연구지
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    • 제25권3호
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    • pp.14-18
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    • 2023
  • 2022년 7월, 국내의 저염분 해수 흰다리새우 양식장에서 양식 중이던 흰다리새우가 이상유영과 식욕부진을 보이며 지속적으로 폐사하였다. 일일 평균 폐사율이 0.1%로 완만한 폐사를 보였으나, 2달 넘게 폐사가 지속되었고 성장 지체로 인한 경제적인 피해가 가중되었다. 질병 진단 과정 중, 폐사 새우의 간췌장에서 세균(KNUAF-SHP3)이 분리되었다. 본 세균의 16S rRNA 유전자의 시퀀스 분석 결과, 분리주 KNUAF-SHP3은 Shewanella에 속하는 균으로 동정이 되었고, S. algae MARS 14, S. chilikensis JC5T와 근연 관계를 보이며 같은 그룹으로 분류되었다. 실험 동물을 활용한 인위 감염 실험에서는 상대적으로 고농도(2.1×108CFU/ml와 2.1×109CFU/ml)를 적용한 군에서는 모든 새우들이 감염 증상을 보이며 감염 후 7일 내에 100% 폐사율을 나타내었다. 본 연구는 Shewanella 세균이 저염분 해수 양식 흰다리새우에서의 잠재적인 기회 감염균이 될 수 있음을 기술하고 있다.

Rotifer, Keratella sp.의 성장을 위한 최적 염분 및 수온 조건 (The Optimal Salinity and Temperature Condition for the Growth of Rotifer, Keratella sp.)

  • 이배익;김신권;권오남;박흠기;박진철
    • 수산해양교육연구
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    • 제25권5호
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    • pp.1205-1213
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    • 2013
  • We investigated the optimum salinity and temperature conditions for the mass culture of small rotifer, Keratella sp.. In the salinity experiment ranging from 0-34‰, the population growth of Keratella sp. drastically increased continuously up to 15‰, and then slightly increased over 20‰. Their maximum density reached 1,007 inds./mL at 0‰. A pre-reproductive phase was shorter in low salinity than in high salinity. The highest number of offspring per female (10.2 inds.) and lifespan of the female (10.7 days) were obtained at 0‰, but there were no significant differences compared to those at 5‰. In the temperature experiments ranging from 16-$32^{\circ}C$, the highest maximum density (1,766 inds./mL) was shown at $24^{\circ}C$. The number of offspring per female significantly increased with increasing temperature, and the highest number of offspring per female was 10.4 inds. at $24^{\circ}C$. The lifespan of female increased with decreasing temperature and the longest lifespan was 12.8 days at $16^{\circ}C$.

Effect of Salinity Stress on Dry Matter Yield and Oxalate Content in Napiergrass (Pennisetum purpureum Schumach)

  • Rahman, M.M.;Ishii, Y.;Niimi, M.;Kawamura, O.
    • Asian-Australasian Journal of Animal Sciences
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    • 제21권11호
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    • pp.1599-1603
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    • 2008
  • Sodium is involved in elevation of oxalate content in some plant species and this element is abundant in saline soils. Oxalate causes precipitation of insoluble calcium oxalate in the rumen and kidneys. The intention of this study was to evaluate the effect of soil salinity stress on dry matter yield and oxalate content in pot-grown napiergrass (Pennisetum purpureum Schumach). Plants were cut three times at 56, 118 and 179 d after transplanting to the pots. Five salinity treatments were used containing various concentrations of NaCl solution as follows: 0, 100, 300, 600 and 900 mM. At 28, 42, 84, 98, 146 and 160 d after transplanting, plants were irrigated with one liter of the particular treatment for each application. Dry matter yield of napiergrass was not affected (p>0.05) by salinity treatments. Plants treated with 100 mM NaCl exhibited a higher soluble oxalate content compared to other treatments, but the differences were not statistically significant (p>0.05). Although salinity treatments had significant (p<0.05) effects on insoluble and total oxalate contents in plant tissue between the 100 and 900 mM NaCl treatments, the differences were too small to be considered biologically important. The present study indicates that where the soil is high in NaCl, napiergrass will tend to grow well and be low in oxalate.

HYCOM 재분석 자료가 재현한 동해 수온 및 염분 평가 (Evaluation of Temperature and Salinity Fields of HYCOM Reanalysis Data in the East Sea)

  • 홍진실;서성봉;전찬형;박재훈;박영규;민홍식
    • Ocean and Polar Research
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    • 제38권4호
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    • pp.271-286
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    • 2016
  • We evaluate the temperature and salinity fields in the East Sea reproduced by the global ocean reanalysis data using HYbrid Coordinate Ocean Model (HYCOM for short). Temporal correlation of Sea Surface Temperature (SST) change between HYCOM and the Group for High Resolution Sea Surface Temperature (GHRSST) are higher in summer than winter. Though distributions of temperature and salinity in the HYCOM are similar to those from historical data (World Ocean Atlas 2013 V2), salinity in the HYCOM is lower (highter) in the region where the salinity is high (low). Temperature fields in the Ulleung basin of HYCOM are quite similar to those derived from Pressure-recording Inverted Echo Sounder (PIES), such as the correlation coefficient is higher than 0.7. This indicates that the HYCOM represents well the circulation and meso-scale phenomena in the Ulleung basin.

韓國 南海의 水溫과 분의 變動係數 (THE VARIATION COEFFICIENT OF WATER TEMPERATURE AND SALINITY IN THE SOUTHERN SEA OF KOREA)

  • 김복기
    • 한국해양학회지
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    • 제17권2호
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    • pp.74-82
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    • 1982
  • 1968-1980年의 韓.日共同海洋調査點中 韓國側 63個定點의 海洋調査資料를 使用하여 月別 水溫 및 분의 變動係數를 分析 硏究한 缺課의 要約은 다음과 같다. 變動係數는 水溫과 분의 前線域이나 혹은 躍層形成海域에서 크게 나타났다. 水溫의 變動係數는 각 水塊의 勞力이 가장 强한 時期에 最大値를 나타냈다(對馬 暖流와 黃海暖流域의 夏季 中層에서, 南海岸沿岸水 및 西海南部域의 冬季의 全層 에서 最大). 鹽分의 變動係數는 東支那海 低鹽水의 影響을 많이 받는 夏季에 暖流系水의 表層水에서 크게 나타나며, 沿岸水 및 西海南部域에서는 暖流系水値의 1/2정도였다.

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Reproduction and Maturation of Sea Bass, Lateolabrax japonicus, after Transportation from Net-Cages to Indoor Tanks

  • Kang, Duk-Young;Kim, Hyo-Chan;Im, Jae Hyun
    • 한국발생생물학회지:발생과생식
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    • 제25권3호
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    • pp.157-171
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    • 2021
  • To determine whether the reproductive processes of sea bass, Lateolabrax japonicus, proceed normally after transportation from an outdoor net-cage into indoor tanks, we examined changes in the gonadosomatic index (GSI), histological gonadal tissue, and plasma levels of sex hormones (testosterone and estradiol-17ß) during their annual reproductive cycle. We also measured maturation and spawning across two sea water salinity levels (full and low salinity). Fecundity was estimated by the relationship between egg number and body size in female sea bass. Monthly changes in the GSI, histological gonadal tissues, and oocyte size showed both male and female sea bass reach final maturation in January and February, respectively, indicating that the spermiation of males occurs earlier than the spawning of females. The histological results indicated that the sea bass is a multiple spawner, similar to many marine teleosts, exhibiting group-synchronous oocyte development. Female maturation and spawning were enhanced in lower salinity seawater (29.6-31.0 psu) compared to that of normal salinity (34.5-35.1 psu). These results confirm that sea bass reproduction can occur successfully in captivity and imply that fertilized eggs can be collected from February to March. Additionally, our results show that lower salinity enhances oocyte maturation and spawning of female sea bass.