• 한국환경과학회지
• /
• 제9권5호
• /
• pp.429-436
• /
• 2000

In order to study on the variational characteristics of water quality and chlorolphyll a concentration the water samples were collected daily or three times a week during the period from April 1990 to November 1991 at Kukdong port located in the northern Kamak bay of Southern Korea I made an analysis on biological factor as chlorophyll a concentration as well as physico-chemical factors such as water temperature salinity sigma-t dissolved oxygen, nutrients (ammonia, nitrite, nitrate, phosphate, and silicate) N/P ratio and chemical oxygen demand. In Northern Kamak bay seasonal variations in physical factors such as water temperature salinity and sigma-t were very marked. On the other hand chemical factors such as nutrients concentration and COD were not so. Chemical factors, in particular silicate were influenced by input of freshwater. And the roles of silicate on the seasonal succession of phytoplankton species composition was very low. Phytoplankton biomass as measured by chlorophyll a concentration was very high all the year round and it was controlled by the combination of several factors especially of N/P ratio determined by dissolved inorganic nitrogen.

• 한국패류학회지
• /
• 제28권1호
• /
• pp.21-28
• /
• 2012

채묘시험은 4구간의 수온구 20.0, 23.0, 26.0, $29.0^{\circ}C$에 염분을 20.0, 30.0, 40.0으로 조절하여 온도와 염분의 혼합구에 대한 참굴 부착기 유생의 채묘시험을 실시한 결과, 수온 $29.0^{\circ}C$에서 염분 20.0과 30.0으로 조절된 채묘구에서 평균 $43.1{\pm}0.19%$와 $42.1{\pm}0.1%$로 유의적으로 가장 높은 채묘율을 보였고, 수온 $23.0^{\circ}C$염분 40.0에서 $34.9{\pm}0.6%$ 가장 낮은 부착률을 보였다 (P < 0.05). 부착밀도는 수온 $29.0^{\circ}C$에서 유의적으로 높았고, 염분 40.0의 고염분에서 유의적으로 낮았다(P < 0.05). 그러나 수온과 염분의 혼합효과는 유의적인 차이가 없었다 (P > 0.05). 수온에 따른 염분별 채묘구의 부착 빈도를 조사한 결과 가장 많은 부착빈도는 1.2-2.3 마리/$cm^2$을 보였고, 평균 부착밀도는 1.9-2.4마리/$cm^2$였다. 전체적으로 채묘율과 평균 부착밀도 그리고 부착빈도를 감안하면 본 실험 결과 효과적인 채묘관리를 위한 수온과 염분조건은 수온 $29.0^{\circ}C$, 염분 20.0-30.0으로 조절하는 것이 좋을 것으로 판단된다.

• 한국해양학회지:바다
• /
• 제9권4호
• /
• pp.153-163
• /
• 2004

In order to estimate the nutrient flux of the Seomjin River into the coastal waters of South Sea, and to understand the estuarine reactions during mixing between river water and seawater, we collected surface water along the salinity gradient in the Seomjin River estuary from Mar. 1999 to Apr. 2001. We found that nitrate and silicate were delivered by fluvial input, while phosphate was, supplied from disposed wastes in the Gwangyang Bay. Mean annual flux of dissolved inorganic nitrogen (DIN), phosphate and silicate into the Gwangyang Bay was estimated 10.9 molesㆍsec$^{-1}$(4,820 tonnesㆍyr$^{-1}$), 0.07 molesㆍsec$^{-1}$(68 tonnesㆍyr$^{-1}$), 13.3 molesㆍsec$^{-1}$(11,747 tonnesㆍy$^{-1}$), respectively. An evident removal of phosphate, silicate and ammonium at the mid-salinity zone during the dry season was attributed to the active uptake of phytoplankton, and consequently nutrient flux into the Gwangyang Bay was low. Whereas, during the flood season in summer, conservative or additional distribution of the nutrients was observed in the estuary. As a rsult nutrient flux into the Gwangyang Bay was maintained high. High concentrations of chlorophyll a and the active removal of nutrient during the dry season at the mid-salinity zone suggest that nutrient distribution in the Seomjin River estuary was mainly controlled by biological processes and nutrient fluxes into the Gwangyang Bay might be significantly modified of by the primary production.

• 한국환경과학회지
• /
• 제20권12호
• /
• pp.1521-1531
• /
• 2011

This study was carried out to determine the characteristics of the marine environment, including nutritional content, in order to clearly understand the outbreaks of Gonyaulax polygramma in the southern coastal areas in August, 2009. Samples were collected at 13 sites and water temperature and salinity were measured using a CTD. Field surveys were twice: the first between August 5-7, the second between August 22-24. The cell density of G. polygramma was 6,500-10,000 cells $ml^{-1}$ during the $1^{st}$ survey, whereas during the $2^{nd}$ survey the range of the cells was recorded from 8,000 to 12,500 cells $ml^{-1}$. Cochlodinium polykrikoides ranged from 0 to 105 cells $l^{-1}$ during the field survey. In water environments, the majority stations during the $1^{st}$ survey showed a nearly homogeneous water column below $1^{\circ}C$ in temperature, as well as similar profiles of salinity. However, the stratification between the surface and bottom was observed in the $2^{nd}$ survey. Regarding nutrients, Dissolved Inorganic Nitrogen (DIN) in the surface ranged from 0.144 to 0.236 mg $l^{-1}$ during the $1^{st}$ survey, and 0.082-0.228 mg $l^{-1}$ during the $2^{nd}$ survey. DIP (Dissolved Inorganic Phosphorus) did not show any difference in concentration between the $1^{st}$ and $2^{nd}$ survey. During August of 2009, the wind speed in the southern waters remained at around ${\leq}2\;m\;s^{-1}$ for about 60% of time, and there was very little precipitation during the month. Irradiance of ${\geq}10$ hr was shown in the late of August. It is thought that a low level of DIN and salinity play an important role as an essential factor for rapid growth, wide distribution and longer duration of red tide in G. polygramma.

• 한국수산과학회지
• /
• 제1권1호
• /
• pp.45-49
• /
• 1968

인천산 굴, Crassostrea gigas, 담륜자의 치사율에 미치는 염도, 온도, 그리고 혼영도의 영향에 관하여 연구하였다. 1. 정상해수로부터 저염도 혹은 고염도인 해수로 옮겨진 굴의 탐륜자는 차차 생명력을 잃었다. 담륜자의 치사율은 각각 저염도인 15 ppt에서 $46\%$이었고 고염도인 35ppt에서는 $47\%$이었다. 2. 고온도인 $40^{\circ}C$ 이상은 정상해수중의 담륜자에 대하여 치사요인이 있고, 특히 $45^{\circ}C$에서는 30분이내에 모두 사망하였다. 그리나 저온은 고온에 비하여 그렇게 치사적인 요인이 아니었다. 각 온도의 30분과 1시간 처리에서 나타난 두 치사곡선간의 차이는 통계학적으로 유의하지 않았다 (P>0.05). 3. 농혼탁도 ($1\%$)는 담륜자의 치사율에 대하여 처리후 단시간내에는 별로 영향을 주지 않았다.

• 한국작물학회지
• /
• 제50권spc1호
• /
• pp.85-87
• /
• 2005

본 연구는 남서해안 간척지에서 토양 염농도(저염; $0.1\%$, 중염; $0.3\~0.4\%$)별로 쌀 품질 향상을 위한 완전 낙수시기를 구명하기 위하여 시험한 결과를 요약하면 다음과 같다. 1. 저염토양에서의 완전낙수시기에따라 $m^2$당 립수가 비슷하여 쌀 수량은 유의차가 없었다. 중염토양에서는 완전낙수시기가 빠를수록 염피해를 받아 등숙비율이 낮아져, 쌀 수량은 출수후 30일까지는 감수하였고 35일 이상에서는 같았다. 2. 토양 염농도간의 쌀 수량은 중염 토양에서 저염 토양의 $64\%$ 수준으로 감소하였다. 3. 저염 토양에서 완전미 비율이 높았으나 현미품위는 처리농도간에 차이를 볼 수 없었다. 4. 2002년 기상은 완전낙수시기에 잦은 강우로, 2003년에는 생육기 저온으로 인하여 완전 낙수시기를 결정하기 어려웠지만 수량 및 도복 등을 고려해 볼 때 저염 토양에서는 출수 후 $20\~40$일에, 중염 토양에서는 출수 후 $35\~40$일에 완전낙수하는 것이 안전할 것으로 생각된다.

• Journal of the korean society of oceanography
• /
• 제38권4호
• /
• pp.211-215
• /
• 2003

A huge freshwater reservoir (ca. 12,000 ha) will be created when the construction of a 33­km dike on a huge mud flat of the Saemankeum areas is established. A large quantity of freshwater will emerge to the adjacent sea from the reservoir through two big gates. Marine organisms outside the dike are expected to frequently experience low salinity waters. To investigate the salinity effects on the dominant metazooplankton in the coastal waters off Saemankeum areas, we measured the survival (Survival 1H and Survival 24H) of 11 different taxa (the copepods Acartia omorii, A. pacifica, Calanus sinicus, Centropages abdominalis, Paracalanus indicus, Pseudodiaptomus inopinus, Tortanus forcipatus, and a hydromedusa, and barnacle nauplius, polychaeta larva, and a chaetognath Sagitta sp.) at salinities of 0, 5, 10, 15, 20, 25, 30, 35, and 40 psu when the organisms were exposed for 1 and 24 h, respectively. Survival 1Hs of P. inopinus and barnacle nauplius were 100% between 5 and 35 psu, while they were 0% at salinities of 0 and 40 psu. Survival 1Hs of A. omorii and A. pacifica, P. indicus, T. forcipatus, and polychaeta larva were 100% at $salinities\;\geq\;10$ psu, while they were 0% at lower salinities. Survival 1Hs of a hydromedusa and Sagitta sp. were 100% at $salinities\;\geq\;15$ psu, while they were 0% at lower salinities. Survival 1H of C. abdominalis and C. sinicus was 100% at $salinities\;\geq\;20$ psu, while they were 0% at lower salinities. Survival 24Hs of A. omorii, A. pacifica, C. abdominalis, barnacle nauplius, and polychaeta larva were the same as Survival 1 Hs at the same salinity, while those of the other metazooplankton were lower than Survival 1Hs. The results of the present study suggest that low salinity water emerging from big gates may cause the death of the metazooplankton, but the salinities at which death of the metazooplankton occurs may differ by species.

• 한국식생활문화학회지
• /
• 제27권2호
• /
• pp.211-224
• /
• 2012

Eggplant pickles were classified into three groups based on salt concentration (1, 3, 5%) and three groups based on drying time (30, 60 and 120 minutes), followed by storage at $5^{\circ}C$ for 28 days. Raw eggplant contains 94.82% water content. The increase in salt concentration and drying time caused a decrease in the moisture content. Compared to the 0.27% ash content of raw eggplant, the ash content of eggplant pickles increased noticeably with increasing salt concentration due to penetration into the eggplant pickles. pH values decreased significantly as the levels of salt concentration and dying time increased (p<0.05). In terms of storage time, pH values decreased from 21 days. The variation in salinity increased significantly as the concentration of salt increased. Compared to normal pickles salted at 5.39% salinity, eggplant pickles constituted 0.27~0.77% (1%), 0.40~1.14% (3%), and 0.47~11.20% (5%) 'low-salinity' eggplant pickles. Reducing-sugar content differed on the dates of 7, 14 and 21 in drying time and at 3% salinity. Hardness differed at 30, 60, and 120M on the 28th and 1, 5% salt concentration. Resilience differed according to drying time and from dates of 0 to 14th. The number of total microbes decreased at low salinity. In terms of storage time, the number of microbes tended to decrease after the 21st. In the consumer preference test, lightness of 5%-30M was the highest value.

• 대한원격탐사학회:학술대회논문집
• /
• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
• /
• pp.344-347
• /
• 2006

China Coastal Water (CCW) usually appears in the seas surrounding Jeju Island annually (June?October) and is very pronounced in August. The power spectrum density (PSD), sea level anomalies (SLAs), and sea surface temperatures (SSTs) were found to peak annually and semiannually. The peaks at intervals of 80-, 60-, and 43-days are considered to be influenced by CCW and the Kuroshio Current. Generally, low-salinity water appears to the west of Jeju Island from June through October and gradually propagates to the east, where CCW meets the Tsushima Current. Empirical orthogonal function (EOF) analysis of SLAs and SSTs indicated that the variance in SLAs and SSTs was 55.70 and 98.09% in the first mode, respectively. The PSD for the first mode of EOF analysis of SLAs was stronger in the western than in the eastern waters because of the influence of CCW. The PSD for the EOF analysis of SSTs was similar in all areas (the Yangtze Estuary and the waters to the west and east of Jeju Island), with a period of approximately 260 days.

• 환경생물
• /
• 제30권4호
• /
• pp.328-338
• /
• 2012

남해 서부 연안역의 식물플랑크톤 군집 및 환경요인의 계절별 변화를 관찰하고자 2009년 4월부터 2010년 2월까지 계절별 조사를 수행하였다. 환경요인의 변화는 multidimensional scaling (MDS)에 따라 수괴의 변화를 분석하였을 때, 남해 연안역 수괴 (SW; South-western coastal Water mass) 및 남쪽에서 유입되는 고염의 외양 수괴(TW; Tsushima current Water mass), 서쪽 제주해협을 통해 유입되는 저염의 서해 연안수괴 (YW; Yellow sea Water mass), 그리고 해안의 하천으로부터 계절적으로 유입되는 담수(CW; Closed bay Water mass)가 영향을 미치고 있었다. 이들 수괴는 해양 환경의 시 (계절) 공간적 특성에 따라 발달과 확장 및 축소되고 있었다. 즉, 연안에서 외해역 또는 외해역에서 연안 방향(남-북 방향) 그리고 서쪽(진도 주변 해역)에서 동쪽 방향 (동서 방향)의 농도 경사를 보인다. 이러한 남-북 방향의 공간 변동은 연안에서 하천과 지하수로 유입되는 연안 담수(낮은 염분과 높은 영양염 농도)와 대마 해류(고염분과 저영양염) 사이의 혼합에 의한 것이며, 동-서방향의 공간 변동은 제주해협을 통해 남해 연안으로 유입되는 서해의 연안수(저염분과 고영양염)와 대마 해류 사이의 혼합에 의해 조절되고 있는 것으로 해석된다. 식물플랑크톤은 고영양염을 보인 서해 연안수 및 여자만, 득량만에서 높은 개체수를 보였다. 식물플랑크톤 군집별 특성은 규조류가 90% 이상 높은 비율을 차지하였으나 대마 해류 수괴에서 와편모조류가 상대적으로 높아 수괴 특성에 따른 분류군의 차이를 보여 수괴가 갖는 기원적 특성 (original characteristics)의 차이를 보였다.