• Ocean and Polar Research
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• v.32 no.3
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• pp.321-329
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• 2010

Photosynthetic pigments, nutrients, and hydrographic variables were examined in order to elucidate the spatio-temporal variation of water column structure and its effect on phytoplankton community structure in the western channel of the Korea Strait in fall 2006 and spring 2007. High phytoplankton biomass in the spring was associated with high salinity, implying that nutrients were not supplied by coastal waters or the Yangtze-River Diluted water (YRDW) with low salinity. Expansion of the Korea Strait Bottom Cold Water (KSBCW) and a cold eddy observed during the spring season might enhance the nutrient supply from the subsurface layer to the euphotic zone. Chemotaxonomic examination showed that diatoms accounted for 60-70% of total biomass, followed by dinoflagellates. Nutrient supply by physical phenomena such as the expansion of the KSBCW and the occurrence of a cold eddy appears to be the controlling factors of phytoplankton community composition in the Korea Strait. Further study is needed to elucidate the mechanisms by which the KSBCW is expanded, and its role in phytoplankton dynamics.

• Journal of Fisheries and Marine Sciences Education
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• v.28 no.5
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• pp.1417-1434
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• 2016

Starting from the February 2008 till the end of November 2014, abundance of phytoplankton and their composition living in the coastal waters of Kyoungju city were investigated. Environmental and biological properties were also observed at 10 different stations on a seasonal basis. Due to the environmental variables, fluctuating pattern was appeared during the entire period of observation with different degree, as compared to those found in other costal waters in the East Sea. The concentration of phosphate was turned out to be very low which was even less than threshold level in the study area. Phytoplankton community structure was dominated by diatoms (both micro- and nanoplankton fractions) for several years and seasonal succession was also relied on the diatoms. The importance of dinoflagellates in the community was relatively low. Abundance of phytoplankton was heavily affected by physical factors in the surface water, however, affected more by chemical factors including nutrients in the deep water. For periods of this study, the phosphate concentrations was observed in an extremely low, which indicates that the main limiting factor affecting phytoplankton growth could be phosphate.

• Korean Journal of Environmental Biology
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• v.40 no.1
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• pp.70-86
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• 2022

A survey was conducted to analyze seasonal dynamics of the phytoplankton community at 22 stations on the surface and bottom layers in the Anma Islands of Yeonggwang(AIY) in the southern West Sea, Korea from the spring of 2020 to the winter of 2021, using a marine survey vessel Ed Ocean. Based on the survey results, there were 87 phytoplankton species in 52 genera, diatoms accounted for 67.8%, dinoflagellates 26.5%, silicoflagellates 3.5%, and cryptomonads and euglenoids accounted for 1.1% each. By season, it was simple in spring and relatively varied in winter. The phytoplankton standing crop on the surface was low (28.8±30.1 cells mL^-1) in summer and high (87.0±65.1 cells mL^-1) in spring. In the phytoplankton community, diatoms showed a high share (over 80%) throughout the year, and Skeletonema costatum-ls was the dominant species with a dominance of more than 60% in spring and winter, and 34.6% and 24.2% in summer and autumn, respectively. The diversity expressing the characteristics of the community structure was high (2.79±0.45) in autumn and low (1.82±0.18) in spring, unlike the phytoplankton standing crop. However, the dominance was high at (0.86±0.08) in spring and low (0.44j0.13) in autumn. Based on the results of principal component analysis (PCA) using environmental and phytoplankton-related factors, it was estimated that the biological oceanographic environmental characteristics seen through the phytoplankton community in the AIY were dominated by nutrients supplied from open seawater and surface sediments by seawater mixing, such as tidal mixing.

• Journal of Plant Biology
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• v.14 no.1
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• pp.15-23
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• 1971

The productivity of summer phytoplankton communities in Lake Hwajinpo, Lake Yongrang and Lake Changja were studied by measuring vertical variation of chlorophyll a amounts. The author also classified the lake types on the basis of the amount of chlorophyll in the lake water. And in Lake Changja, the seasonal changes of stratification of chlorophyll were studies. In Lake Hwajinpo, the productive structure of the phytoplankton community in summer was found to be L-shaped and of the mesotrophic type. In Lake Yongrang, the productive structure of the phytoplankton community in summer was alo L-shaped and of the mesotrophic type. And maximum chlorophyll layer was near the lake bottom below the compensation depth. In Lake Changja, the structure of phytoplankton community in summer was reversed L-shaped and of the eutrophic type, with the maximum chlorophyll layer just below the surface. The vertical distribution of chlorophyll amounts as a measure of the productive structure almost always formed a stratum distribution except in September and sometimes in May, in Lake Changja. In September homogeneous distribution was observed.

• 한국해양학회지
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• v.19 no.1
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• pp.68-81
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• 1984

To characterize community structure and distribution of phytoplankton, cluster analyses are performed on quantitative data of phytoplankton collected from the southwestern sea of Korea in early summer, 1980. The cluster analysis shows that the phytoplankton of the study area consists of three distinct characteristic communities, representing different water masses. The species of the first community, predominant in the southwestern coastal were of the main land, are mostly neritic and cold water diatoms. The second community consists of neritic and oceanic diatoms, a few flagellates and an euglenoid. These species are predominant in the vicinity of Jeju Island with warm and high saline waters which seems to be a branch of the Kuroshio Current. The species of the last community, consisting primarily of small-sized dinoflagellates, are predominant in the rest part of the study area with warm and low saline water. Addition, the vertical distributions of phytoplankton and environmental factors show that high concentration of phytoplankton cells, chlorophyll-a and dissolved oxygen are observed near the seasonal pycnocline in the off-coastal area. Fraction of nanoplankton take the above 90% of the total cell concentration in the surface mixed layer of off-coastal area where the seasonal pycnocline develops in summer.

• Korean Journal of Ecology and Environment
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• v.35 no.3 s.99
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• pp.187-197
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• 2002

To analyze the structure of phytoplankton community of the Asan Reservoir in Korea, samples were collected 6 times from March to November in 1997. A total of 204 phytoplanklon species were identified from the samples of 19 stations. Green algae dominated the phytoplankton community, accounting for 51% of species number, followed by diatoms (29%), cyanobacteria (12%), dinoflagellates (2%) ,euglenoids (3%) and other flagellates (3%). Standing stocks of phytoplankton were very high in the range of 741-613,066 cells/ml, with the highest standing stock in July. Water Booms seemed to occur in the Asan Reservoir regardless of seasons, with water bloom-causing species being Micractium pusillum, Stephanodiscus, hantzschii, Dictyospharium pulchellum, cryptomonad(> 20 ${\mu}$m), Microcystis aeruginosa, Oscillatoria tenuis, Oscillatoria sp., Aphanocapsa sp. Euglena sp., Volvox aureus. In the summer, cyanobacteria dominated algal bloom. Species diversity of phytoplankton community in the reservoir was in the range of 0.13 ${\sim}$ 3.20, and showed much difference temporally and spatially. The cluster analysis identified two different regions of upstream area and downstream area for the Asan Reservoir.

• Korean Journal of Environmental Biology
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• v.22 no.3
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• pp.426-437
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• 2004

To understand the phytoplankton community in adjacent waters of Ulchin nuclear power plant (UNPP), abundance and the size fractionated $chl-\alpha$ concentrations were evaluated through seasonal interval sampling from April 2003 to February 2004. A total of 211 different phytoplankton species was observed and mean abundance of phytoplankton in each study period ranged from 244,286 to 1,221,779 cells $L^{-1}$. The contributions of microplankton $(>20\mu{m})$ to total phytoplankton abundance ranged from 42.5 to 83.6% (average 66.1%) and those of nanoplankton $(>20\mu{m})$ ranged from 16.4 to 57.5% (average 33.9%). Total chl-$\alpha$ concentrations of phytoplankton ranged from 0.52 to $2.26\mu{g}\;L^{-1}$. The contribution of chl-$\alpha$ concentrations of microplankton was higher than that of nano- and picoplankton through the study period with exception of July 2008. The results of abundances and $chl-\alpha$ concentrations suggest that microplankton has an important role in adjacent waters of UNPP. The diminution of abundances and $chl-\alpha$ concentrations of phytoplankton was observed after passage through the cooling water system, but it was gradually recovered by mixing with the ambient waters. Our results suggested that the influence of thermal discharges on phytoplankton should be restricted within narrow limits around outlet area of thermal effluents.

• Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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• v.2 no.1
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• pp.21-28
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• 1998

A total of 94 taxa were identified from the Southern Ocean, 140-148 $^{\circ}E$ and 40-53 $^{\circ}S$, as an early austral summer phytoplankton. They were 53 diatoms, 37 dinoflagellates, 2 silicoflagellates, 1 prymnesiophyte, and 1 coccolithophorid. Integrated cell numbers of nanoplankton dominated microphytoplankton from 8 stations, especially from Subantarctic zone, but integrated biomass was lower than microphytoplankton. Integrated cell numbers of diatoms dominated dinoflagellates, coccolithophorids, and prymnesiophyte, but integrated biomass of microphytoplankton were dependent to the biomass of dinoflagellates except north of the Subtropical convergence zone and south of the Antractic convergence zone. Phytoplankton community changed across the fronts and 3 different communities were observed. Fronts seem to influence on the phytoplankton community from the west Pacific Sector of the Southern Ocean.

• Proceedings of KOSOMES biannual meeting
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• 2009.06a
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• pp.157-158
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• 2009

Phytoplankton plays an important part as indicator and primary producer in marine ecosystem. Therefore, phytoplankton community appeared variously according to marine environment, so the data of nutrients, chlorophyll a, temperature, salinity, and DO were analyzed in seagrass bed of Yeoja Bay. Consequently, the phytoplankton community structures were associated with investigation time and place, and seen difference according to the existence and nonexistence of seagrass bed.

• Journal of Environmental Science International
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• v.2 no.1
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• pp.21-28
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• 1993

A total of 94 taxa were identified from the Southern Ocean, 140-148 。E and 40-53。S, as an early austral summer phytoplankton. They were 53 diatoms, 37 dinoflagellates, 2 silicoflagellates, 1 prymnesiophyte, and 1 coccolithophorid. Integrated cell numbers of nanoplankton dominated microphytoplankton from 8 stations, especially from Subantarctic zone, but integrated biomass was lower than microphytoplankton. Integrated cell numbers of diatoms dominated dinoflagellates, coccolithophorids, and pnrnnesiophyte, but integrated biomass of microphytoplankton were dependent to the biomass of dinoflagellates except north of the Subtropical convergence zone and south of the Antractic convergence sone. Phytoplankton community changed across the fronts and 3 different communities were observed. Fronts seem to influence on the phytoplankton community from the west Pacific Sector of the Southern Ocean.