• 한국해양학회지
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• v.23 no.1
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• pp.1-12
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• 1988

To clarify the community structure of phytoplankton in the Kyeonggi Bay, the community analysis were performed to investigate the relationship between the environmental factors and the phytoplankton communities. Low diversity with occurrence of few dominant species throughout the year, except summer, implies that ecological environment of this study area is very unstable due to incessant physical perturbation and large fluctuation of other environmental factors. According to the results of the cluster analysis this study area could be divided into river discharge, polluted and unpolluted area. Principal component analysis of overall phytoplankton community in this area clearly showed four seasonal succession patterns grouped into the spring type, the summer type, the late summer type, the late autumn-winter type. Summer communities composed of common phytoplankton are highly correlated with temperature and transparency. Winter communities composed of most tychopelagic plankton are positively correlated with suspended substances and nutrient, while negatively correlated with transparency.

• Journal of the korean society of oceanography
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• v.38 no.3
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• pp.111-121
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• 2003

The seasonal succession of zooplankton communities in the coastal area off Incheon, Kyeonggi Bay, was investigated with the samples collected at intervals of 10 to 15 days from January 1999 to December 2000. Total abundance of zooplankton communities showed remarkable seasonal variations, ranged from 1,100 to $120,400{\;}indiv./\textrm{m}^3$, and annual mean abundance was $22,000{\;}indiv./\textrm{m}^3$. There were several times of the total abundance during a year, and the timing ofhigh abundances were about the same in 1999 and 2000. During the study period except summer, the abundance of dinoflagellate Noctiluca scintillans and copepod Acartia hongi contributed to the most part of total zooplankton. Whereas, during summer, smaller copepod Oithona davisae and Paracalanus crassirostris were dominant species. Zooplankton communities in the coastal waters off Incheon showed typical characteristics of coastal-estuarine communities, which were dominated by a few species, and abrupt seasonal variations in abundance. We suggest that the seasonal succession and abundance variations of zooplankton communities were caused by the seasonal variations in water temperature and by the seasonally varying phytoplankton biomass in the study area.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.11-21
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• 2020

In this study, we compared the spatio-temporal differences of phytoplankton communities among 4 lakes in the Boseong River basin. Field research was conducted quarterly from 2014 to 2017 for this study. A total of 345 species of phytoplankton were identified including 107 Bacillariophyceae, 175 Chlorophyceae, 27 Cyanophyceae and 36 other phytoplankton taxa. Lake Boseong showed higher species numbers and density of phytoplankton than other lakes (Dunn's test, P<0.01). Bacillariophyceae such as Asterionella formosa, Aulacoseira granulata, Fragilaria crotonensis was dominated in most research periods, whereas Scenedesmus ecornis and Coelastrum cambricum belonging to Chlorophyceae were dominant species on August. The self-organizing map (SOM) classified 3 clusters with 10 × 7 grid and showed spatio-temporal variation of phytoplankton communities based on significant difference among each clusters. Total 31 species of phytoplankton were chosen as a indicator species using indicator species analysis(ISA) and reflected seasonal phytoplankton succession and diversity and density of phytoplankton according to nutrient concentration. Water temperature, Secchi depth, conductivity and DO were identified as important factors affecting the differences of phytoplankton communities in the studied lakes in Boseong River basin using non-metric multidimensional scaling (NMDS).

• ALGAE
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• v.19 no.4
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• pp.321-327
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• 2004

The literature review on the dynamics of the phytoplankton communities in terms of species composition, standing crops, abundant species and dominant species in the lower part of the Han River from 1940s to 2000s was conducted for the prospective prediction of their succession patterns. Total of 326 taxa were identified and they belonged to 47 blue-green algae, 139 green algae, 12 euglenoids, 126 diatoms, 6 din flagellates and 2 silicoflagellates. Composition of phytoplankton communities were 83.6% diatoms, 10.5% blue-green algae and 5.3% green algae in the middle of 1960s, whereas those were 43.2% diatoms, 40.7% green algae and 13.6% blue-green algae in the 1990s. Before 1990s, Synedra ulna, Melosira varians, Cymbella tumida, Synedra acus, Cymbella ventricosa, Navicula cryptocephala, Nitzschia palea, Aulacoseira granulata, Gomphonema parvulum and Cymbella affinis were most frequent, while those after 1990 were Asterionella formosa, Asterionella gracillima, Aulacoseira granulate, Aulacoseira granulata var. angustissima, Chlorella vulgare, Fragilaria crotonensis and Synedra ulna. Phytoplankton blooms were frequent from winter to the late spring and rare in summer due to heavy rain and discharge. Seasonal variations of the dominant species were fairly obvious; Asterionella gracillima and Aulacoseira granulata in spring, Aulacoseira granulate and Aulacoseira granulate var. angustissima in summer and autumn, Asterionella gracillima and Stephan discus hantzschii in winter. Recently blue-green algae, Microcystis, Aphanocapsa, Dactylococcopsis have been more abundant than those of the previous reports. Based on the current situations, Stephan discus hantzschii f. tennis, Asterionella gracillima, Aulacoseira granulate and blue-green algae will be more abundant and blooms of those species will be more frequent.

• Journal of Environmental Science International
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• v.26 no.8
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• pp.913-925
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• 2017

Phytoplankton populations were examined at three sites in Lake Cheongpyeong, South Korea from March 2008 to December 2016, including measurement of phytoplankton communities and their dominant species, abundance and environmental factors. The annual average ranges of water temperature, dissolved oxygen and conductivity were $15.2-18.8^{\circ}C$, 10.3-12.2 mg/L, $86-140{\mu}S/cm$, respectively, with similar values at all studied sites. The highest phytoplankton cell density was observed in spring and fall, and it subsequently decreased rapidly during heavy rainfall. Diatoms were dominant in spring (mainly Stephanodiscus hantzschii, Asterionella formosa) and fall (mainly Aulacoseira granulata), while greenalgae and cyanobacteria had high appearance in early-summer and summer, respectively, indicating that water temperature is the most important factor influencing their growth. Stephanodiscus hantzschii and Asterionella formosa frequently occurred at low water temperature ($4.5-15.0^{\circ}C$ and $5.4-21.6^{\circ}C$, respectively) while Aulacoseira granulata and Anabaena spp. were favored by high water temperature (8.6-28.4 and $14.9-26.2^{\circ}C$, respectively) and phosphorus. Additionally, Fragilaria crotonensis occurred at low nutrient conditions. Rhodomonas spp. frequently appeared year-round.

• Korean Journal of Environmental Biology
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• v.21 no.1
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• pp.8-17
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• 2003

The spatio-temporal distribution and seasonal fluctuations of phytoplankton community were carried out in the Southwestern parts of Deukryang Bay of the Korean South Sea from July 1997 to January 1998. A total of 60 species of phytoplankton belonging to 41 genera was identified. In the southwestern parts of Deukryang Bay seasonal succession in dominant species; Eucampia zodiacus, and Chaetoceros spp. in summer, Nitzschia longissima, Chaetoceros curvisetus and Bacillaria paxillifera in autumn, Skeletonema costatum and B. paxillifera in winter, were very predominant. The community structure of phytoplankton in the southwestern parts of Deukryang Bay appeared to be diverse in species composition, and diatoms were most dominant through the year. Phytoplankton standing crops fluctuated with an annual mean of $1.2{\times}10^5$ cells $L^{-1}$ between the lowest value of $8.0{\times}10^3$ cells $L^{-1}$ in January and the highest value of $6.9{\times}10^5$cells $L^{-1}$ by Nitzschia longissima in January. Densities of the phytoplankton cell number by the samples of the southwestern parts of Deukryang Bay ranged from $1.1{\times}10^4$ cells $L^{-1}$ to $1.3{\times}10^5$ cells $L^{-1}$ with the mean value of $4.1{\times}10^4$ cells $L^{-1}$ in summer, from $1.0{\times}10^4$ cells $L^{-1}$ to $6.9{\times}10^5$ cells $L^{-1}$ with mean of $1.8{\times}10^5$ cells $L^{-1}$ in autumn, from $8.0{\times}10^3$ cells $L^{-1}$ to $4.6{\times}10^5$ cells $L^{-1}$ with mean $1.6{\times}10^5$ cells $L^{-1}$ in winter. That is to say, phytoplankton standing crops was high in low temperature seasons, while low in high temperature seasons. Chlorophyll a concentration fluctuated between 1.08 mg $m^{-3}$ and 21.6 mg $m^{-3}$ in January. In the southwestern parts of Deukryang Bay temporal change in chl-a concentration was not apparent. But chl-a concentration was high during a year. Therefore, phytoplankton production in the southwestern parts of Deukryang Bay could be very high year-round.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.33 no.1
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• pp.43-50
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• 2000

The obseuations on the seasonal fluctuations of phytoplankton community in Haechang Bay of the Korean southern sea were carried out during four seasons from 1997 to 1998. A total of 77 species of phytoplankton including 10 freshwater species, belonging to 51 Benera was identified. Seasonal succession of dominant species was evident in Haechang Bay; Chaetoceros cunisetus, Skeletonema costatum, Eurampia zodiacus, Dictyocha fibula and Ceratium furca in summer, C. curisetus in autunm, C. cunisetus Rhizosoienia setigera and E. zodiacus in winter and S. costatum in spring. The phytoplankton community in Haechang Bay showed various species composition and was occupied with centric diatoms all the year round, Densities of the phytoplankton cell number by the samples of Haechang Bay ranged from $8.4{\times}10^3\;cells/l\;to\;2.0{\times}10^5\;cells/l$ with the mean value of $9.2{\times}10^4\;cells/l$ in summer, from $3.2{\times}10^3\;cells/l\;to\;4.6{\times}10^6\;cells/l$ with mean of $6,2{\times}10^4\;cells/l$ in autumn, from $8.4{\times}10^3\;cells/l\;to\;4.3{\times}10^4\;cells/l$ with mean $2.2{\times}10^4\;cells/l$ in winter and from $1.0{\times}\;10^3\;cells/l to\;4.6{\times}10^4\;cells/l$, with mean of $1.1{\times}10^4\;cells/l$ in spring. Phytoplankton standing crops fluctuated with an annual mean of $4.7{\times}10^4 cells/l$ between the lowest value of $1.0{\times}10^3\;cells/l$ in spring and the highest value of $4.6{\times}10^5 cells/l$ in autumn, That is, phytoplankton standing crops was high in summer and autumn, while it was very low in winter and spring.

• ALGAE
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• v.19 no.3
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• pp.235-245
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• 2004

A study on seasonal characteristics of phytoplankton dynamics and environmental factors was carried out at four stations including Mara-do and U-do located in the western and eastern coast of Jeju Island in southern Korea from April 2003 to March 2004. Out of 101 phytoplankton species identified, 84 belong to Bacillariophyceae, 9 Dinophyceae, 6 phytoflagellates and 2 coccolithophorids, and the highest value of species diversity was observed in April. Phytoplankton was more abundant at the western coast than at the eastern coast from March to September and its highest abundance was 49.24 ${\times}$ 10$^3$ cells L$^{-1}$ at Mara-do in July. The pennate diatoms were more abundant at the western coast than at the eastern coast with the highest abundance of 38.75 ${\times}$ 10$^3$ cells L$^{-1}$ at Mara-do in July, and during this period Nitzschia longissima contributed 68.5% of the total phytoplankton abundance. Naviculaceae was more abundant at Gosan (western coast) in November when Stauroneis membranacea represented 80.1% of the abundance. Leptocylindrus dances contributed 49.4% of the abundance at U-do in November. Dinophyceae was more abundant at U-do in August. Water temperature and pH fluctuated from 11.7${^{\circ}C}$ to 27.1${^{\circ}C}$ and from 7.31 to 8.70, respectively. Water temperature of Mara-do was about 1-2${^{\circ}C}$ higher than the other stations. Salinity varied from 30.4 to 35.0 psu with the minimum in rainy season and the maximum at the end of winter. The concentration of NH$_4$-N, NO$_3$-N, NO$_2$-N, PO$_4$-P and SiO$_2$-Si ranged 0.07-6.79, 1.0-62.0, 1.0-8.0, 1.0-7.0 and 7.0-191.0 $\mu$g-at L$^{-1}$, respectively. Chlorophyll a concentrations varied from 0.10 to 1.17 $\mu$g L$^{-1}$. NH$_4$-N concentrations were high at U-do from May to December, and at Mara-do from January to February. The high concentrations of NO$_3$-N were found at Mara-do from June to September and at U-do from January to May. The effects of various physicochemical parameters on the seasonal distribution and succession of phytoplankton population suggest that there is a classical pattern of phytoplankton dynamics in Jeju coastal waters.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.477-493
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• 2020

This study conducted a seasonal survey to analyze the spatio-temporal variations of marine environments and phytoplankton community in Gochang Coastal Waters (GCW) from August 2016 to April 2017. In the results, the water temperature ranged from 2.1℃ to 34.5℃, showing a large seasonal variation, but the salinity changed from 31.14 psu to 32.64 psu. Therefore, the seasonal variations of water types in GCW were mainly determined by water temperature. The phytoplankton community consisted of 53 genera and 86 species, showing a relatively simple distribution. The phytoplankton cell density ranged from 2.2 to 689.2 cells mL^-1, with an average of 577.2 cells mL^-1, which was low in autumn and high in winter. The seasonal succession of phytoplankton dominant species was mainly diatoms during the whole year, Leptocylindrus danicus, Chaetoceros curvisetus, Skeletonema costatum-ls in summer, Paralia sulcata, Eucampia zodiacus in autumn, S. costatum-ls, Thalassiosira nordenskioeldii in winter, and S. costatum-ls, Asterionella glacialis in spring. In other words, the phytoplankton community showed high diversity in GCW throughout the year. According to the PCA, GCW were easily heated and cooled by radiant energy at lower depth, and the seasonal distributions of phytoplankton were determined by the supply of nutrients by re-fuelling of surface sediments due to the seawater mixing such as tidal mixing.

• ALGAE
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• v.18 no.2
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• pp.135-143
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• 2003

The seasonal dynamics of phytoplankton and trophic state were evaluated weekly at three sites in the Lake Unmoon from May to November 2001. The seasonal succession pattern of phytoplankton community in the Lake Unmoon showed that the dominant species were; i) diatoms during the late spring, ii) dinoflagellates in June, iii) blue green algae, diatoms and dinoflagellates in July, iv) green algae and blue green algae in August, v) blue green algae in September and early November, and vi) diatoms in November. Members of Microcystis were dominant from middle August to late October and members of Aulocoseira appeared as important species in autumn in the Lake Unmoon. The concentration of chlorophyll-a ranged from 2.4 to 23.0 mg ${\cdot}m^{-3}$ (average: 8.6 mg ${\cdot}m^{-3}$) during the study period. Concentrations of total phosphorus were high during the period from July to November with the maximum of 0.028 mg ${\cdot} l^{-1}$. The average N/P ratio was 121, indicating that concentrations of phosphorus may determine the high algal biomass in the Lake Unmoon. Concentrations of silicate were higher in the Lake Unmoon (average value: 10.016 mg ${\cdot}$ l-) than in other lakes (average values: 1.074-4.408 mg ${\cdot}$ l-), suggesting high potential of diatom growth. The average trophic state index in the Lake Unmoon was 52, which was close to eutrophic state, and the trophic state trend was increasing steadily since 1999.