• 한국환경과학회지
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• 제21권3호
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• pp.313-326
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• 2012

Three embankments, namely Changpo, Bokkil and Guil, in Chunggye Bay were investigated to assess the influence of environmental changes to phytoplankton size structure, distribution of species and standing crops. Three stations was sampled near at each embankment in Nov. 2006, Feb. 2007, May 2007 and Aug. Phytoplankton were classified into net-size (>20${\mu}m$) and nano-size (<20${\mu}m$). In summer, the freshwater discharge seemed to have influence in the decrease of salinity and in the increase of turbidity, ammonium and phosphorus concentrations. Chl a concentration and phytoplankton abundance in Feb. 2007 were observed to be generally higher in all stations compared to other periods. Net-size phytoplankton was observed to be higher in Feb. 2007 and May 2007 compared to nano-sized phytoplankton. However, there was shift in phytoplankton composition in Nov. 2006 and Aug. 2007. Phytoplankton under seven class (Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae) was identified during the study period. It was found out that the major phytoplankton class was Bacillariophyceae. Phytoplankton was more diverse in autumn compared to any other season. Cyanophyceae was increased in summer. In rainy season, change in physical factors (salinity, transparency) seemed to have more influence on phytoplankton growth compared to inorganic nutrients.

• 대한원격탐사학회지
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• 제18권3호
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• pp.127-139
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• 2002

A comparison was made between the chlorophyll $\alpha$ and suspended solid (SS) retrievals from OSMI and SeaWiFS sensor to chlorophyll $\alpha$ and SS values determined with the standard method during the NFRDI's research cruises. The percentage of organic and inorganic materials from the SS was calculated to study the contribution of turbid water in the northern part of the East China Sea. The open sea waters in the Kuroshio regions of the East China Sea showed relatively higher concentration of volatile SS. However, towards the northwestern part of the East China Sea, the situation became much more optically different with the non-volatile SS from the Yangtze river and the sea bottom sources in the sea in winter and spring seasons. Furthermore, in order to indirectly detect low salinity water with high turbidity, which related to the Yangtze river using remote sensed data from the satellites, a comparison between the results of the band ratio(nLw 490nm/nLw 555nm) of SeaWiFS(OSMI) and the distribution of low salinity around the Jeju Island was presented.

• Ocean and Polar Research
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• 제28권4호
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• pp.395-405
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• 2006

We measured the fugacity of $CO_2$ $(fCO_2)$, temperature, salinity, nutrients and chlorophyll a in the surface water of the western North Pacific $(4^{\circ}30'{\sim}33^{\circ}10'N,\;144^{\circ}20'{\sim}127^{\circ}35'E)$ in September 2002. There were zonally several major currents which have characteristics of specific temperature and salinity (NECC, North Equatorial Counter Current; NEC, North Equatorial Current; Kuroshio etc.). Surface $fCO_2$ distribution was clearly distinguished into two groups, tropical and subtropical areas of which boundary was $20^{\circ}N$. In the tropical Int surface $fCO_2$ was mainly controlled by temperature, while in the subtropical area, surface $fCO_2$ was dependent on total inorganic carbon contents. Air-sea $CO_2$ flux showed a large spatial variation, with a range of $-0.69{\sim}0.79 mmole\;m^{-2}day^{-1}$. In the area of AE (Anticyclonic Eddy), SM(Southern Mixed region) and NM (Northern Mixed region), the ocean acted as a weak source of $CO_2$ $(0.6{\sim}0.79 mmole\; m^{-2}day^{-1})$. In NECC, NEC, Kuroshio and ECS (East China Sea), however, the fluxes were estimated to be $-0.3mmole\; m^{-2}day^{-1})$ for the first three regions and $-1.2mmole\; m^{-2}day^{-1})$ for ECS respectively, indicating that these areas acted as sinks of $CO_2$. The average air-sea flux in the entire study area was $0.15mmole\;m^{-2}day^{-1})$, implying that the western North Pacific was a weak source of $CO_2$ during the study period.

• Fisheries and Aquatic Sciences
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• 제1권1호
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• pp.122-128
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• 1998

Characteristic changes in chlorophyll fluorescence from thalli of red alga, Porphyra, under high salt stress and during subsequent recovery were investigated, and the differences in the sensitivity to the stress among four species of Porphyra with different intertidal distributions were compared. By the treatment of NaCl with $9\%$ or higher concentrations, photochemical efficiency (Fv/Fm) decreased in a biphasic pattern: a rapid decrease was observed within 1­3 h and followed by a slow decline. The decrease of Fv/Fm was mainly due to the increase of Fo without significant increases of Fm. When the thalli treated with $15\%$ NaCl for 6 h were returned to natural sea water for recovery, the increase of Fv/Fm also showed a biphasic pattern: a rapid increase of Fv/Fm was observed within 2 h and followed by a slow increase. Differences in the sensitivity to salt stress among the four species could be found during recovery after the treatment of severe salt stress. After the treatment of $20\%$ NaCl for 6 h, Fv/Fm decreased below 0.3 in all of the four Porphyra species, and the species living in upper parts of the intertidal zone (P. suborbiculata and P. pseudolinearis) could recover better compared with the species in lower parts of the intertidal zone (P. seriata and P. yezoensis), during recovery for 24 h. The species collected from the coast of the South Sea seemed to be more tolerant than those in the East Sea.

• 한국어류학회지
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• 제17권3호
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• pp.205-216
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• 2005

한국 남해안에서 2003년~2004년의 4월, 6월, 8월에 멸치 알의 분포 및 해양환경 특성을 비교하고 냉수대 형성과의 관계를 분석하였다. 조사해역의 수온은 $10.2{\sim}30.7^{\circ}C$, 염분은 25.7~34.7, 클로로필은 $0.14{\sim}0.67{\mu}g/L$, 동물플랑크톤은 $111.52{\sim}262.37mg/m^3$의 범위였다. 멸치 알은 수온 $14.7{\sim}26.9^{\circ}C$와 염분 31.0~34.6 범위에서 주로 나타났고, 봄에서 여름으로 진행될수록 고수온과 저염분역에서 출현하였으며, 동물부유생물 생산의 증가와 함께 알의 평균분포밀도도 높아졌다. 2004년 8월의 멸치산란장은 외양의 난류수와 연안 냉수대간의 수온전선 외해측 해역에 집중되는 경향을 보이므로 연안역의 냉수대형성이 멸치 산란장분포의 제한요인이 되는 것으로 분석되었다.

• 환경생물
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• 제21권2호
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• pp.132-141
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• 2003

We carried out a study on thermohaline structure and phytoplankton com munity in the East China Sea during early summer in 2005. As a result of marine environment and phytoplankton community, three characteristics of water type were identified. The former was characterized by the dominant species with diatoms, Chaetoceros lacinious, Ch. decipiens, Guninardia flaccida, Paralia sulcata, Pseudonitzschia pungens and Pseudosolenia calcar-avis in Chinese coastal waters, the secondary was done by lower water temperature, salinity and the dominant species with dinoflagellates, Prorocentrum donghaiense and Ceratium fusus, in over-all areas and the latter was done by the dominant species with coastal species of diatoms, Skeletonema costafum and Nitzschia longissima and silicoflagellate, Dictyocha speculum var. octopers in the transfer areas of Chinese continental coastal waters. Phytoplankton community in the surface layer identified a total of 66 species belonging to 36 genera. Dominant species was Prorocentrum donghaiense, Chaetoceros lacinious, Skeletonema costatum. Standing crops of phytoplankton in the surface layer flue tuated between $1.5 \times 10^4$cells $L^{-1}$ and $3.5\times 10^{5}$ cells $L^{-1}$. And the highest value appeared in the Changjiang estuaries with high dominance by diatoms and lowest one occurred in the southwestern area of Jeju Island with high dominance by dinoflagellates. Red tides with dinoflagellate, Prororcentrum donghaiense appeared in the frontal areas with mazimum cell density, $3.4\times 10^5$ cells $L^{-1}$. And outbreak environments was low water temperature under $20^{\circ}C$, and low salinity under 31.55 psu. The vertical distribution of red tide organisms went to about 30m depth from surface.

• 한국수산과학회지
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• 제45권6호
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• pp.694-703
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• 2012

To understand the characteristics of sedimentary and benthic environments in habitats of naturally-occurring intertidal benthic macroalgae, various geochemical parameters of sediment (grain size, ignition loss [IL], chemical oxygen demand [COD], and acid volatile sulfur [AVS]) and pore water (temperature, salinity, pH, and nutrients) were measured in the southern intertidal zone of Hampyeong Bay at two month intervals from April to October 2009. Ecological characteristics including the distribution and biomass of benthic macroalgae were also investigated. Benthic macroalgae were distributed below 4 to 5 m depth from mean sea level near the lower portion of the intertidal zone where air exposure time is relatively short. The distribution area and biomass of benthic macroalgae gradually decreased during the study period. The surface sediments in the benthic algal region were mainly composed of finer sediments, such as slightly gravelly mud and mud. The temperature, salinity, pH, and nutrient concentrations (except dissolved inorganic nitrogen) in pore water did not differ in regions with and without benthic macroalgae, whereas the mean grain size and the concentrations of IL, COD, and AVS in sediments were much higher in regions harboring benthic macroalgae. The correlation between mean grain size and IL in sediments displayed two distinct gradients and the slope was much steeper in regions harboring benthic macroalgae, indicating that the content of organic matter in benthic algal region is not solely dependent on mean grain size. Our results indicate that the benthic macroalgae in the southern intertidal zone of Hampyeong Bay play an important role in the accumulation of organic matter in sediment.

• 환경생물
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• 제18권4호
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• pp.411-424
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• 2000

연안생태계의 호염성 톡토기와 개미군집의 생물다양성정도와 변동에 대해 알아보기 위해, 주변환경과 식생이 다른 세지역에서 정량채집을 실시하였다. 종조성이나 분포에 영향을 주는 요인을 찾기 위해 pH, 염도 및 전기전도도를 측정하였다. 연구결과 톡토기의 종조성 이나 분포에는 pH와 식생보다도 토성과 염도가 더 큰 영향을 주는 것으로 나타났다. 그러나 개미의 경우는 집을 지을 적당한 장소를 제공해 줄 수 있는 식생과 조수에 의한 침수에 더 큰 영향을 받는 것으로 사료된다. 모든 조사지역에서 조상대가 조간대보다 다양도가 높았으며 조간대중에서는 모래함량이 높은 동호의 상조대에서 가장 높게 나타났다

• 수산해양기술연구
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• 제27권3호
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• pp.170-177
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• 1991

수영만으로 유입되는 수영강수에 의한 하구의 물리적인 특성을 밝히기 위하여 1989년 5월부터 1990년 4월까지 월별로 관측된 염분 자료와 Officer(1977)가 제안한 식을 이용하여 담수량 및 그 체류 시간을 계산하였다. 그 결과, 수평적으로는 수영만의 동백섬을 기준으로 수영강과 접하고 있는 만 안쪽으로 저염화가 강하게 나타나고 연직적으로는 강 혼합과 부분 혼합의 특징이 나타났다. 그리고 수영강을 중심으로 광안리 쪽이 해운대쪽보다 높은 담수율을 나타내었다. 그리고 거리에 따른 담수율의 분포 특성을 알아보기 위하여 수영강에서 외해쪽으로 6개 정점에서 각각 계산한 담수율을 각각의 최대치로 나누어 계절별로 정규화한 결과 담수율이 지수함수적으로 감소하였다. 추계에는 정점C3를 기준으로 감소율이 다른 계절에 비해 현저히 떨어졌는데, 이것은 성층에 기인한 것으로 보인다. 그리고 앞에서 구한 담수율을 이용하여 수영강에서 유입되는 담수의 체류시간을 계산한 결과, 약 1.3일인 하계를 제외하고 나머지 계절은 약 10~15일 정도임이 밝혀져 하계가 다른 계절이 비하여 담수의 순환이 빠름을 알 수 있었다.

• 한국수산과학회지
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• 제56권5호
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• pp.626-633
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• 2023

Vibrio spp. are aquatic bacteria that are ubiquitous in warm estuarine and marine environments. Especially, V. vulnificus and V. cholerae are currently known to cause potentially fatal infections in humans. This study investigated the distribution and antibiotic resistance of V. vulnificus and V. cholerae isolated from coastal areas of Gyeongsangnam-do in 2022. A total of 252 samples of water, shellfish and coastal sediment were collected from 7 locations along the coast, and 124 samples of fishery products were collected from markets. Among the 252 samples, forty-four V. vulnificus (11.7%) and fourteen V. cholerae non-O1/non-O139 (3.7%), none of which carried the ctx gene, were isolated. Out of the 124 samples, 6 (4.8%) tested positive for V. vulnificus and V. cholerae was not detected. The isolation rates of V. vulnificus and V. cholerae showed a significant correlation with environmental factors such as seawater temperature and salinity. In an antibiotic resistance test, V. vulnificus was susceptible to amikacin, gentamicin, imipenem trimethoprim/sulfamethoxazole, and ciprofloxacin, but resistant to cefoxitin (100.0%), followed by tetracycline (9.1%). Multidrug resistance was also observed. Continuous monitoring of Vibrio pathogens with water temperature and salinity is expected to help reduce the outbreaks, and rational use of antibiotic agents is needed to prevent the accession of antibiotic-resistant microorganisms in aquatic ecosystems.