• 미생물학회지
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• 제26권3호
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• pp.256-261
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• 1988

낙동강 하구 생태계의 종속영양세균의 특성과 이에 미치는 환경요인의 영향을 조사하였다. 해수역에 위치한 정점에서 분리한 세균군집이 담수역에서 분리한 군집보다 광염성 세균으로 이루어져 있으며, 하계에 분리한 군집이 동계군집에 비해 광온성세균으로 구성되어 있었다. 또한 수계의 세균군집은 육상에서 유입되는 비토착성세균에 의해 다양성이 커지며, 환경이 악화되면 세균군집의 다양성이 감소하는 현상이 관찰되었다.

• 한국양식학회지
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• 제21권4호
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• pp.331-338
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• 2008

본 연구는 황복 Takifugu obscurus를 대상으로 1995년 3월부터 1996년 2월까지 자연산 황복의 생식소중량지수(GSI), 간중량지수(HSI)의 월별 변화와 산란기 동안 산란지역의 수질환경을 조사하였다. 또한 2004년 7월부터 2005년 6월까지 육상수조에서의 저염분사육에 따른 GSI, HSI의 월별 변화를 조사하였고, 생식소의 외부 형태, 배우자 형성과정 중 생식세포 분화, 생식소발달 단계에 따른 생식주기를 광학현미경으로 연구하였다 자연산 황복의 산란장소인 충남 강경의 적정 수질환경은 수온 $15-20^{\circ}C$ 염분은 0 psu였으며, GSI 월별 변화는 암컷과 수컷에서 5월에 최대값을 보인 후 6월에 급격히 낮아져 자연상태에서 황복의 산란기는 5-6월로 추정되었다. 자연산 황복의 GSI와 HSI 사이에는 음의 상관관계를 나타내었다. 저 염분으로 사육한 황복 암컷과 수컷의 생식소 외부형태는 좌 우측에 한 쌍의 낭상구조를 이루고 있다. GSI의 월별 변화를 근거로 실내 수조에서 저염분으로 사육한 황복의 암 수 개체들은 3-5월에 산란하는 것으로 추정되었으며, 자연산과 비슷하게 GSI와 HSI 사이에는 음의 상관관계를 보였다. 생식소발달 단계에 따른 생식주기는 암컷에서 초기성장기, 후기성장기, 성숙기, 완숙 및 산란기, 회복 및 휴지기의 5단계로 구분할 수 있었고, 수컷에서는 성장기, 성숙기, 완숙 및 방정기, 회복 및 휴지기의 연속적인 4단계로 구분되었다. 황복은 자연산의 경우, 연중 한 번의 산란기를 가지나 육상 양식장에서 고수온($20-27^{\circ}C$) - 저염분(3.3 psu 이하) 조건에서 사육하면 연중 다회 산란, 방정이 가능한 생식 특성을 가진다.

• 수산해양기술연구
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• 제34권2호
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• pp.117-134
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• 1998

The study on the Assembling Mechanism of the Hairtail, Trichiurus lenpturus, at the Fishing Grounds of the Cheju Strait had been investigated by analyzing the relationship of the oceanographic conditions and the fishing ground of the Hairtail in the Cheju Strait. 1. The fishing grounds of the hairtail at the Cheju Strait are formed at the bottom of a high temperature of the tidal front at the coast. area of northern Cheju Island, the tip of the linguiform is high in salinity at the eastern and western entrances of Cheju Island, low salinity eddy on the surface and its surrounding front, various water masses in the Strait and coastal waters of the South Sea in Korea. 2. The fishing grounds of the Hairtail at the Cheju Strait begins with the sea surface temperature higher than $15^{\circ}C$ and the incoming of low salinity water now from the East China Sea. 3. Estimation of optimum temperature and salinity per season based upon analysis for relationship between temperature of water and salinity of the bottom layer and the catch is : 15.2~$16.4^{\circ}C$, 34.20~34.40${\textperthousand}$ in spring(June); 14.4~ $17.0^{\circ}C$, 33.70~34.30${\textperthousand}$ in summer(July~September); and 15.7~ $18.6^{\circ}C$, 33.70~34.50$\textperthousand$ in autumn(October~December). Hairtail are mostly caught at the Yellow Sea Warm Current and Tsushima Current with temperature over $14.5^{\circ}C$ and salinity over 33.70${\textperthousand}$ at the bottom layers of the Cheju Strait. 4. Considering the relationship between the amount of hairtail catch and the water temperature of bottom layer, when the bottom water being above $14.0^{\circ}C$ flowed into Cheju Strait through the western entrance of the strait in summer, the ca-h appears to have been abundant. In contrast, the catch has been poor when the temperature of such water was recorded to be below $13^{\circ}C$ Therefore, distribution patterns of water at the bottom layer can be used as a forecast index whether the catch of a certain year will be good or poor.

• 한국수산과학회지
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• 제54권5호
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• pp.714-723
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• 2021

This study investigated the quality characteristics of anchovy Engraulis japonicus sauce added with onion to improve flavor, reduce salinity, and enhance the antioxidative activity. 4 samples were prepared to find the proper amount of onion, including a control group without onion and 3 samples with different amounts of onion: 10% (Fs-10), 20% (Fs-20), and 40% (Fs-40). The samples were collected at intervals of 15 days while fermenting at 25℃ for 60 days. As the amount of added onion increased, the browning index decreased, and the flavor of anchovy sauce was enhanced. The composition of amino acids showed high content of glutamate and alanine that can improve the overall taste. In the free radical scavenging activity test, the Fs-40 group showed the highest value, 74.72%, compared to 10.98% of the control in the antioxidative activity. When evaluating overall preference such as color, fishy smell, flavor with richness, and overall acceptability, the control was rated the lowest, while the Fs-40 was rated the highest and was recognized for its overall excellence. Adding onion not only reduced salinity and increased antioxidant activity but also improved overall sensory properties by adding richness and minimizing fishy smell.

• 한국환경과학회지
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• 제11권12호
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• pp.1205-1215
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• 2002

To evaluate the change for water quality after the water gate operation in Shiwha lake, in situ survey were conducted on september in 2000 and January, march, jane in 2001. Chemical characteristics and eutrophication level was estimated from the survey data. The water quality of the Shihwa lake was greatly affected by pollutant load from rainfall, and formation of stratification in summer and winter was increased to effect on nutrient release from sediment. Especially, high concentration of chlorophyll-a was occurred in autumn, due to increased nutrient, high water temperature and low salinity after rainfall runoff. The mean concentration of DIN, DIP were 0.346mg/L, 0.0217mg/L in surface water and 0.826mg/L, 0.0415mg/L in bottom water, respectively, which were over III grade of seawater standard. Also high percentage of ammonia nitrogen to DIN in bottom water for autumn and winter was affected by released nutrient from sediment. Correlation analysis of chlorophyll-a versus TSS was shown that organic matter was affected by autochthonous organic matter stem from the algae, these factor showed reverse correlation about salinity. Closely correlations among to the water quality constituent in continuity survey was appeared. The results of eutrophication index estimation showed the high potentiality of red tide occurrence in Shiwha lake, particularity in summer or fall. Overall water quality was greatly improve to compared with measuring data during 1997~1998 at the beginning water gate operation, which reported by KORDI. Therefore, to improve of water quality in Shiwha lake, we need to establish of management plan about nutrient release from sediment, rainfall runoff, maximum of seawater exchange.

• 환경생물
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• 제18권1호
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• pp.95-104
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• 2000

In order to elucidate chatracteristics of water quality and seasonal dynamics of phytoplankton community in Kyungpo lake, the weekly variation of algal population and 11 environmental factors were investigated from March 1998 to February 1999. A total 121 species of phytoplankton belonged to 57 genera, 4 genera 7 species of the Euglenophyceae, 1 genera 2 species of the Chrysophyceae, 2 genera 3 species of the Cryptophyceae, 1 genera 1 species of the Dinophyceae, 6 genera 9 species of the Cyanophyceae, 28 genera 78 species of the Bacillario-phyceae and 15 genera 21 species of the Chlorophyceae, was identified. Cryptomonas sp., Chamydomonas sp., Nitzschia frustulum, Oscillatoria sp., Lyngbya sp, and Dictyosphaerium pulchellum occurred successively as dominant phytoplankton species from March 1998 to February 1999. Density of phytoplankton cell number showed the peak in early April when Chlamydomoas sp. was dominated. The diversity index of phytoplankton community showed low values in the dominating period of Cryptomonas sp. and Chlamydomonas sp. The concentration of chlorophyll a fluctuated between 1.09 and 107.7$\mu\textrm{g}$ㆍ1$^{-1}$. Water temperature, salinity, DO, conduc tivity and SS were ranged 0.5-27.8$^{\circ}C$, 2.8-25.2 ppt, 4.62-19.21 mgO$_2$ㆍ1$^{-1}$, 5.33-34.76 mS/cm and 0.017-0.184 mgㆍ1$^{-1}$, respectively. Annual means of Secchi disc transparency was 36cm and thai of pH value was 8.5. The concentrations of PO$_4$-P was ranged 0.0012-0.077 mgㆍ1$^{-1}$ , and showed high value from August to October. The concentrations of NO$_2$-N, NO$_3$-N and NH$_4$-N was ranged 0.0011-0.1 mgㆍ1$^{-1}$, 0.074-3.33mgㆍ1$^{-1}$ and 0.0024-0.259 mgㆍ1$^{-1}$, respectively. Among environmental factors, water temperature was negatively correlated with DO, salinity and conductivity, DO was positively correlated with salinity and conductivity. Chlorophyll a, one of the indicies of eutropication in lake, was negatively correlated with NH$_4$-N. The cell density of Cryptomonas sp., which was the most dominant species in this lake, was negatively correlated with transparency. [Kyoungpo lake, Phytoplankton, Cryptomonas sp. , Chlamydomonas sp., Seasonal variation].

• 한국해양환경ㆍ에너지학회지
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• 제19권4호
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• pp.274-285
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• 2016

동해중부연안(후포~거진)에서 해수 중 해양환경특성의 시공간적 분포양상을 살펴보기 위해서 2013~2014년에 계절별로 현장조사를 실시하였다. 표층 수온과 염분은 하계에 고온 저염, 동계에 저온 고염의 분포 양상이 뚜렷하게 나타났다. 저층 수온은 약 $2{\sim}7^{\circ}C$ 범위로 겨울에 상대적으로 높았으며, 염분은 약 34로 계절별로 큰 차이를 보이지 않았다. 표층수중 용존산소 농도는 약 $7{\sim}12mg\;L^{-1}$의 범위로 다른 계절에 비해 5월(평균: $11.4{\pm}0.3mg\;L^{-1}$)에 상대적으로 높았다. 표층수에서 수온과 용존산소 농도는 가을과 겨울에 유의한 음의 상관관계를 보여 이 시기에 수온이 용존산소량을 조절하는 주요인자인 것으로 판단된다. 표층수 중 용존무기질소와 용존무기규소는 여름에 비해 겨울에 각각 약 11배, 7배 높았다. 표층수 중 DIN:DIP 비는 약 16이었으나 봄인 5월에 상대적으로 낮은 값을 보였다. 반면 여름에는 상대적으로 높은 비를 보여 봄에는 질소, 여름에는 인이 식물플랑크톤의 성장에 제한인자로서 작용했을 것으로 판단된다. 해수 수질은 조사기간동안 I(매우좋음)~III(보통) 등급 수준이었으며, 상대적으로 낮은 저층 용존산소 포화도를 보인 가을에 일부 정점에서 IV 등급 수준으로 나타났다.

• 한국패류학회지
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• 제15권2호
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• pp.71-79
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• 1999

To develop new products for aquaculture, which fishermen at South Sea can get high income, after bay scallop was transplanted from Sandong province in China from October 17, 1996 to March 18, 1997 at Duekrang Bay in Janghung gun and Kamak Bay in Y대녀 City on Chollanam province, Sumjin river estuary in Hadong gun and Gejae Bay in Keoje city on Kyongsangnam proince. Temperature was decreased from 20.5$^{\circ}C$ to 5.1$^{\circ}C$ in February and then it was increased to 12.0 in March. Ranges of salinity, DO and Chlorophyll-a were 22.40-34.70 psu, 5.24-9.77 mg/l and 1.27-22.28 $\mu\textrm{g}$/l, respectively, and low temperature, sudden changes of salinity and low concentration of chlorophyll-a influenced the growth of bay scallop. bay scallop in the rearing period showed the fastest growth from October 17 to November 18 through the every size rages, while it grew slowly or stopped growing from December 18 to March 18. Among 4 transplanted areas, young scallop at Duekrang Bay showed the fastest growth and then Kamak Bay, Gejae Bay, Sumjin estuary in order. The daily growth rate of young scallop in the middle size range (5.70%) was higher than those in large (2.07%) and small (5.49%) size range. The meat weight index showed the highest in December. Survival rates from October to December were high, not related to the size ranges, but survival rate of the small young scallop from January to March was higher than Those of the rest. As the Result, transplanted bay scallop at South Sea was shown to grow by the middle of December (around 1$0^{\circ}C$ temperature).

• 생물환경조절학회지
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• 제29권4호
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• pp.354-364
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• 2020

본 연구는 원통형 종이포트를 활용한 토마토 육묘시, 염스트레스를 활용하여 고온기 도장 억제가능성을 검토하기 위하여 수행되었다. 시험구는 K₂SO₄, KCl과 KH₂PO₄을 각 5, 10 dS·m^-1로 처리하였고, 또한, 토마토 모종에 고염도의 칼륨을 처리하여 수분 및 저온스트레스 환경에서의 적응성 및 생존성을 조사하였다. 조사결과, 처리 농도가 높아질수록 지상· 하부 건물중, 옆면적, 순동화율 (NAR)이 감소하고, 경경과 충실도는 증가하였다. 수분 스트레스 처리 이후, 대조구는 심한 위조현상을 보였지만, KCl처리구는 양호하였다. 상대수분함량은 대조구에서 23%, KCl처리구에서 8% 감소 하였다. 또한, 대조구에 비하여 KCl 처리구는 저장시(9, 12 및 15℃ 모종의 손상 비율이 낮았다. 이와 같은 결과로 보아, KCl과 같은 고농도의 칼륨 처리가 원통형 종이포트 토마토 육묘의 도장 억제에 효과적이며 환경 스트레스 내성을 향상시키는 것으로 판단된다.

• Ocean and Polar Research
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• 제27권1호
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• pp.45-58
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• 2005

Temperature, salinity, dissolved oxygen, COD, dissolved inorganic nitrogen(DIN), dissolved inorganic phosphorus (DIP), and chlorophyll were measured in the surface and bottom waters of Cheonsu Bay in April, August, December 2003, and Hay 2004. DIN showed a large seasonal variation, with higher values in summer and lower in spring. The significant decrease in DIN concentration was observed from April to May, which may imply the occurrence of spring phytoplankton bloom sometime in these periods. In contrast, DIP did not show distinct seasonal variation, with relatively low values compared with other coastal regions. The low DIP concentration in Cheonsu Bay is ascribed to a limited phosphorus input around Cheonsu Bay. The Nf ratios of Cheonsu Bay much higher than the Redfield ratio(16) in all season indicate that phytoplankton growth is limited by phosphorus. Based on low chlorophyll concentrations and eutrophication index, Cheonsu Bay has not been in eutrophic condition during our observation periods. In the artificial lakes located around Cheonsu Bay, however, chlorophyll concentrations were very high, mostly over $10{\mu}g\;l^{-1}$, indicating that they are now in severe eutrophic condition.