• 한국환경생물학회:학술대회논문집
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• 한국환경생물학회 2003년도 학술대회
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• pp.103-107
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• 2003

Spatial distribution of phytoplankton was investigated in the southwestern sea of Korea in May 2000 in terms of phytohydrography. The sampling was done at the 0m, 30m, 50m of 15 selected stations, and permanent slides of each samples were prepared by QPS method for quantitative and qualitative analyses. Phytoplankton standing crops ranged from 3.23${\times}$10$\^$-4/ to 1.09${\times}$10$\^$-7/ cellsㆍ$\ell$$\^$-1/ in the study area. Dominant species comprised of 9 diatoms and 2 phytoflagellates, showing higher dominance of diatom and most predominance of Skeletonema costatum in all layers of most stations. Phytohydrographic results indicate that the study area might be divided into 4 categories, that is, I area is designated as neritic area where occurrence of terrestrial and coastal species is frequent, II area as intermediate area, III area as offshore area where oceanic species dominate, and IV area as other's. Especially in the II area, Skeletonema costatum was most predominant at both surface and 30m layer in most stations and represent an characteristic of northward expansion with spring massive bloom.

• 한국환경과학회지
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• 제9권5호
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• pp.375-384
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• 2000

It is very important to interprete and simulate the variation of phytoplankton maximum region for the prediction and control of red tide. This study was composed of two parts first the hydrodynamic simulation such as residual current and salinity diffusion and second the ecological simulation such as phytoplankton distribution according to freshwater discharge and pollutant loads. Without the Nakdong river discharge residual current was stagnated in inner side of this estuary and surface distribution of salinity was over 25psu. On the contrary with summer mean discharge freshwater stretched very far outward and some waters flowed into Chinhae Bay through the Kadok channel and low salinity extended over coastal sea and salinity front occurred. From the result of contributed physical process to phytioplankton biomass the accumulation was occurred at the west part of this estuary and the Kadok channel with the Nakdong river discharge. When more increased input discharge the accumulation band was transported to outer side of this estuary. The frequently outbreak of red tide in this area is caused by accumulation of physical processes. The phytoplankton maximum region located inner side of this estuary without the Nakdong river discharge and with mean discharge of winter but it was moved to outer side when mean discharge of the Nakdong river was increased. The variation of input concentration from the land loads was not largely influenced on phytoplankton biomass and location of maximum region. When discharge was increased phytoplankton maximum region was transferred to inner side of the Kadok channel. ON the other hand when discharge was decreased phytoplankton maximum region was transferred to inner side of this estuary and chlorophyll a contents increased to over 20$\mu\textrm{g}$/L Therefore if any other conditions are favorable for growth of phytoplankton. decreas of discharge causes to increase of possibility of red tide outbreak.

• Journal of Plant Biology
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• 제15권s호
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• pp.1-32
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• 1972

In order to utilize for the prevention and preservation of the Han River from the environmental pollution the present studies were carried out to clarify the microflora and estimation of the water pollution levels of the Han River. In addition to the above regional and seasonal fluctuation of the phytoplankton was also examined. Samples of phytoplankton were collected from 6 stations in the South Han River during the period from December, 1971 to October, 1972. The results obtained during the present studies are as follows: 1. The phytoplankton samples collected from 6 stations, Yeoju, Hajapo-ri, Yangpyeong, Daruraegi, Giduwon and Paldang were identified and classified by Engler's classification system(1954). It resulted in 2 phylum, 2 classes, 7 orders, 10 families, 29 genera, 137 species, 1 sub-species, 49 varieties, 6 forma and 2 variety-forma. The total numbers of phytoplankton identified were 195 species, of which 7 families, 27 species, 26 varieties, 4 forma and 2 variety-forma are new to Korea, that of 54 species are first described in Korea. 2. In lower area of the Han River it is found 53 species from Paldang and in middle area it is found 114 species from Giduwon, 95 species from Daruraegi, 66 species from Yangpyeong, 71 species from Hajapori and 81 species from Yeoju. In standpoint of seasonal fluctuation of phytoplankton, the total numbers of the plankton is more abundant in summer than in winter season and it shows bimodal pattern. 3. As compared with previous data which obtained from 30 stations covering estuary to upper area, both South and North Han River, during the period from 1965-1972 it is shown that 10 species of the South Han River and 11 species of the North Han River are found throughout all seasons. Among the above species two are common in both area. In the other hand it is found that 9 species in spring season and 6 species in fall season in the South Han River and 10 species in spring, 23 species in summer, 4 species in fall and 15 species in winter season in the North Han River shows their seasonal fluctuation in this area. Among the seasonal occurrence of phytoplankton 10 species were consider to be indicator for the estimation of biological water pollution levels. 4. According to Fjerdingstad's water pollution level system (1963) the total numbers of 1, 230 species which have been collected from the Han River since 1965 includes 27 species of phytoplankton as indicator; 3 species of blue-green algae, 20 species of diatom, and 4 species of green-algae. 5. With 27 indicator species new estimation of water pollution level system was arranged for water pollution in the Han River. 6. The lower part of the central area of the Han River indicates mesosaprobic. In central area of the Han River shows mesosaprobic and oligosaprobic, but predominant in mesosaporobic. And it is indicated that mesosaprobic, oligosaprobic, and polysaprobic factors mixed up in the North Han River. Compare with their water pollution level in the South and North Han River, with author's new system, it is estimated that North Han River is more polluted than South Han River. 7. The reason why North Han River is more polluted suggested that the selfpurification action was limited by their circulation speed. The rapid speed of water in the North Han River is mainly caused by their topography and water-drainage from waterpower plant. In conclusion the central area of the Han River consist of mesosaprobe zone, as a part with oligosaprobe zone. But the presence of polysaprobe zone in the North Han River gives us many problems in future for the nationa development programme and natural conservation in this area.

• 한국해양학회지
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• 제18권2호
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• pp.91-103
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• 1983

1981년 9월에 한국동남해역의 연안역, 대륙붕역 및 대륙사연역에 이르는 각 수역에서 수심 별로 채집된 식물 플랑크톤의 정성 및 정량시료를 분석하였다. 본 연구에서는 185종류의 식물 플랑크톤을 동정하였으며, 이는 규조류 124종류, 쌍편모조류 56종류, 규질편모류 3종류 및 각 1종류씩의 갈색편모조류와 유글레나류 로 구성되어 있다. 식물 플랑크톤 군집을 분석한 결과 연구해역은 2개의 식생역 으로 구분됨을 알게 되었고, 해수의 물리적 특성에 의하여 이들 식생역의 범위가 크게 좌우됨이 밝혀졌다. 동남 연안역의 경우 식생은 매우 풍부하였으며 소형 규조류와 미세 편모류가 주종이었고 연구 해역의 북부 수역에서는 여러 종류의 규류조 및 쌍편모조류가 다량 출현하였다. 식물 플랑크톤 현존량을 해수의 물리적 특성, 식물 플랑크톤의 종조성과 비교하였다. 연구 해역의 북부 수역에서는 식물 플랑크톤의 현존량분포에 있어서 대마난류수와 북한한류 계수의 혼합이 특히 중요함을 알게 되었다.

• 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.

• 생태와환경
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• 제35권3호통권99호
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• pp.187-197
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• 2002

아산호에서 1997년 3월부터 1997년 11월까지 6회에 걸쳐 식물플랑크톤 군집구조를 파악하기 위한 연구를 수행하였다. 19개 정점에서 관찰된 식물플랑크톤 분류군은 총 204종군으로, 각 분류군별 출현비는 녹조류 51%, 규조류 29%, cyanobacteria 12%, 와편모조류가 2%, 유글레나류 4%, 기타 편모조류가 2% 이었다. 식물플랑크톤의 현존량은 741ce11s/m떼서 613,066ce11s/ml의 범위로 매우 높은 수준으로 나타났다. 현존량은 7월에 가장 높았고 9월, 6월, 3월, 11월, 5월 순으로 나타났다. 계절에 관계없이 지속적으로 녹조상태인 것으로 판단되며, 녹조원인생물은 Micractium pusillum, Stephandiscus hantzschii, Dictyospharium pulchellum, cryptomonad (> 20 ${\mu}$, Microcystis aeruginosa, Oscillatoria tenuis, Oscillatoria sp., Aphanocapsa sp. Euglena sp., Volvox aureus 이었다. 여름철에 cyanobacteria에 의한 녹조현상이 현저하였다. 식물플랑크톤의 종다양성은 0.13${\sim}$의 범위로 시${\cdot}$공간적으로 차이가 매우 컸다. 집괴 분석한 결과 전반적으로 아산호 하류수역과 상류수역 투 개의 수역으로 구분이 되었다.

• 한국해양학회지
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• 제15권2호
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• pp.89-99
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• 1980

The major source of nutrients in both the Gamagyang Bay and the Yeoja Bay is mixing. However, water discharges also seem to contribute significant quantities which may influence local phytoplankton growth. Data collected inn the study area shows that natural fluctuations in the environmental conditions of the entire area play a dominant role in determining the phytoplankton populations of the two Bays. The predominating phytoplankton forms are neritic diatom species including some dinoflagellate species in summer. Neritic groups are relatively more abundant in inner areas of the Bays. The oceanic groups and species are seasonal, and associated with advective effects. One neritic species is of overwhelming numerical importance and occurs when a specific seasonal conditions is formed. Species cycles in the two Bays may be regarded as largely the result of successional changes or cycles of autochthonous species introduced by advective processes.

• Journal of Ecology and Environment
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• 제32권4호
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• pp.221-227
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• 2009

This study describes time lag responses between hydrological variables and phytoplankton biomass in a regulated river system, the lower Nakdong River in South Korea. The lower Nakdong is a typical flow-controlled lotic system, and its limnological characteristics are influenced by climatic variation such as monsoons and summer typhoons. Mean rainfall in the area during summer is about 1,200 mm, which comprises >60% of annual rainfall. Our results show that the regulation of flow in the Nakdong by multi-purpose dams from 1995 to 2004 affected phytoplankton dynamics. Diatom blooms occurred in winter, when the limited discharge allowed for proliferation of the phytoplankton community. Using multiple regression analysis, we detected significant time-delayed relationships between hydrological variables and phytoplankton biomass. These results may be useful for water resource managers, and suggest that 'smart flow' control would improve water quality in large regulated river systems of the Republic of Korea.

• Ocean and Polar Research
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• 제40권4호
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• pp.191-202
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• 2018

In this study we conducted a weekly monitoring exercise at a fixed station in the saltwater zone during the dry season (Jan-Mar, 2013) and wet season (Jun-Aug, 2013) to understand the fluctuations in phytoplankton communities and environmental factors in the Youngsan River estuary altered by a dike constructed in the coastal area. Phytoplankton communities displayed seasonality; diatoms were dominant during the dry season whereas dinoflagellates were dominant during the wet season. T-test analysis showed that water temperature was significantly different between the seasons whereas freshwater discharge from the dike was not significantly different. This suggests that seasonal variations of phytoplankton are more likely affected by water temperature than freshwater discharge. However, a short-term fluctuation was also observed in response to freshwater discharge; freshwater species appeared during or after the discharge in the dry and wet seasons and blooms of harmful species developed after the discharge. Phytoplankton communities may be affected by changes in physical factors such as turbidity and salinity and nutrient supply resulting from freshwater discharge. Especially, the nutrient supply may directly contribute to the harmful algal blooms (HABs) composed of dinoflagellates which can adapt to low salinity after freshwater discharge.

• Ocean and Polar Research
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• 제33권2호
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• pp.99-111
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• 2011

To estimate the effects of limitation nutrients for phytoplankton growth and its influences on short-term variations of a winter phytoplankton community structure, we investigated the abiotic and biotic factors of surface and bottom waters at 20 stations of inner and offshore areas from 6 to 7 February in Gwangyang Bay, Korea. Also, several algal bio-assay studies were conducted to identify any additional nutrient effects on phytoplankton assemblage using surface water for the assay. The dominant species in the bay was diatom Skeletonema costatum, which occupied more than 70% of total species in most stations (St.1-16) of the inner bay. According to a cluster and multidimensional scaling (MDS) analysis based on phytoplankton community data from each station, the bay was divided into three groups. The first group included stations from the south-western parts of Myodo lsland, which can be characterized as a semien-closed eutrophic area with high phytoplankton abundance. The second group included most stations from the north-eastern part of Myodo lsland, influenced indirectly by surface water currents from offshore of the bay. The standing phytoplankton crops were lower than those of the first group. The other cluster was restricted to samples collected from offshore of the bay. In the bay, silicon (Si) and phosphorus (P) were not a major limiting factor for phytoplankton production. However, since the DIN: DIP and DSi: DIN ratios clearly demonstrated that there were potential stoichiometric N limitations, nitrogen (N) was considered as a limiting factor. Based on the algal bio-assay, in vivo fluorescence values in N (+) added experiments were higher compared to control and P added experiments. Our results suggested that nitrogen may act as one of the most important factors in controlling primary production during winter in Gwangyang Bay.