• Journal of environmental and Sanitary engineering
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• v.10 no.2
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• pp.36-45
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• 1995

Physicochemical environments and phytoplankton community in the nakdong river middle basin were investigated during a period of 1 year from Nov. 1993 to Oct. 1994. The ranges of Physicochemical environment factors in the nakdong river middle basin were $3.6~27.4{\circ}C$ for temperature, 7.1~9.3 for pH, $7.1~12.7mg/{\ell}$for DO, $0.7~2.1mg/{\ell}$ for BOD, $31~52mg/{\ell}$ for alkalinity, $2.101~3.3mg/{\ell}$ for T-N, $0.052~0.099mg/{\ell}$ for T-p, $5.4~92.3mg/m^{3}$ for chlorophyll-a. The number of Phytoplankton was lowest in Jan. that is, 244ce11s/ml and that was highest in Sep. 1201 cells/ml. The increase of dominant genera were correlated with the total nomber of phytoplanktons. Bacillariaceae, chlorophyceae, cyanophyceae, and euglenophlrceae were to 74.5%, 20%, 3.5%, and 2.2% respectively. Bacillariaceae were abundant during all the year round except for Jun, Jul, Aug. Chlorophyceae were plentiful in Jun, Jul, Aug. Tase-and odor-causing algae and filter clogging algae were 72% in Nov. and 93.5% in Jun. They were abundant all the year round except for winter, so they influenced on the treatment of tap water system. They belong to the general asterionella, cyclotella, melosira, nitzschia of bacillariaceae and actinastrum, pediastrum of chlorophyceae. Dominace index was low in winter and high in umber. Diversity index and equitability index were low in summer and high in winter. Therefore, the structure of phytoplankton community of the nakdong river middle basin was different form season to season.

• Journal of Ecology and Environment
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• v.42 no.4
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• pp.240-258
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• 2018

Background: Several investigations carried out from large brackish lagoons in South Korea. However, no studies have yet examined phytoplankton in lagoons that changed to freshwater, such as Cheonjin Lake. The present study examined the algae from Cheonjin Lake. Methods: Samples were collected at monthly inetrvals from May 2017 to April 2018, from the surface layer using a plankton net (mesh size $20{\mu}m$), and sequeezing submerged macrophytes. Microscopic examinations were conducted at a magnification of 200 to 1000x using a Zeiss microscope (Axio Imager. A2), and photographs were taken with an AxioCam HRC camera. Silica-scaled samples of Chrysophyta for SEM were placed on coverglass, air dried, coated with gold, and then examined with a Hitachi SV8220 SEM. Results: A total of 376 taxa from six major algal groups (Chlorophyta, Chrysophyta, Euglenophyta, Cyanophyta, Dinophyta, and Cryptophyta) were identified. Among these algae, 28 taxa of desmids, 9 taxa of Euglenophyceae, 4 taxa of Chlorophyceae, 2 taxa of Chrysophyceae, and 1 taxon of Xanthophyceae are reported for the first time in Korea. A new species, Cosmarium hexagonum sp. nov was described. The phytoplankton communities were characterized by an abundance of Desmids (within Charophyceae) accounted for 148 taxa from 22 genera. Species richness were particularly high in the Autumn. Conclusion: In this study, a total 376 taxa of 148 desmids (Charophyceae), Chlorophyceae (103 taxa), Chrysophyceae (53 taxa), Euglenophyta (49 taxa), Dinophyta (8 taxa), and Cryptophyta (2 taxa) were identified from Cheonjin Lake. Twenty-eight taxa of desmids including a new species (Cosmarium hexagonum sp. nov.), 9 taxa of Euglenophyceae, 4 taxa of Chlorophyceae, 2 taxa of Chrysophyceae, and 1 taxon of Xanthophyceae were newly recorded in Korea.

• Korean Journal of Environmental Biology
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• v.24 no.3
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• pp.221-229
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• 2006

The effects of ultrasonication on phytoplankton were investigated in two ponds in which physicochemical and biological water quality was similar, one as a treatment and the other as a control. The samples were collected from August 18 to September 30 in 2003. Traditional morphological analysis showed that Bacillariophyceae dominated phytoplankton community in both ponds. The abundance of Cyanophyceae was lower in the phytoplankton community of the sonicated pond than that of control pond. We used DGGE (denaturing gradient gel electrophoresis) to analyze the diversity and change of phytoplankton community in two ponds. The DGGE banding patterns of 16S rRNA gene and sequence analysis demonstrated that Oscillatoria acuminata and CFB (Cytophaga-Flavobacterium-Bacteroides) group bacterium appeared in the treated pond, and the control pond was dominated by Synechococcus sp. and Aphanizomenon flos-aquae. Especially, Pseudanabaena sp. dominated during the ultrasonic cessation in the treated pond. The DGGE profiles of 18S rRNA gene and sequence analysis showed that the treated pond was dominated by Chlamydomonas reinhardtii and the control pond by C. reinhardtii and Pteromonas protracta. In conclusion, the ultrasonication affected the reduced growth of cyanobacteria, particularly Pseudanabaena.

• Korean Journal of Ecology and Environment
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• v.45 no.1
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• pp.21-33
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• 2012

Survey on the phytoplankton community structure and distribution in the upstream watershed of the East River was carried out during the period from May, 2008 to April, 2009. A total composition of phytoplankton included 159 taxa, consisting of 7 orders, 56 genera, 139 species, and 40 unidenfied species. Among those, the diatoms and green algae were more frequently found during the investigation than the other taxa. Cocconeis placentula, Cymbella minuta, Diatoma vulgare, Melosira varians, Navicula cryptocephala, Scenedesmus acuminatus v. acuminatus, were among the most common. The standing crops of the phytoplankton ranged from 86 cells $mL^{-1}$ to 1,467 cells $mL^{-1}$. The dominant species were Achnanthes minutissima, Asterionella formosa, Aulacoseira ambigua, Cocconeis placentula, Coelastrum microporum, Cyclotella sp., Cymbella affinis, C. minuta, C. tumida, Diatoma vulgare, Fragilaria capucina, F. construens, F. crotonensis, Gomphonema affine, G. clevei, Melosira varians, Merismopedia elegans, Navicula cryptocephala, N. pupula, Nitzschia tryblionella, Oscillatoria anna, O. limosa, O. tenuis v. tenuis, Pediastrum duplex v. reticulatum, Phormidium tenue, Scenedesmus acuminatus v. acuminatus, S. acutus v. acutus, S. ecornis v. ecornis, S. quadricauda v. quadricauda, Spirogyra sp., Stigeoclonium sp., Synedra acus, S. ulna, and Ulothrix sp. The most dominant species was Cymbella minuta. The diversity index, evenness index, and dominance index ranged from 1.58 to 3.10, 051 to 0.95, and 0.22 to 0.74, respectively. The phytoplankton community structure of upstream stations of the survey area was influenced by the effluent of the Doam Lake.

• Korean Journal of Environmental Biology
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• v.27 no.1
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• pp.48-57
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• 2009

The characteristics of physico-chemical factors and the species compositions of phytoplankton were investigated to analyze the marine ecosystem at the depths during summer in the coast of Dokdo (stations DOK1$\sim$3). The mean values of conductivity (32 mS cm$^{-1}$), total dissolved solids (45 mg L$^{-1}$), salinity (35.5 psu), total suspended solids (39 mg L$^{-1}$) were the highest in DOK1. The biomass (chl-${\alpha}$) of phytoplankton was the highest in the surface of station DOK1 (3.1 ${\mu}g$ L$^{-1}$). By means of physico-chemical factors (salinity, turbidity, chl-${\alpha}$, T-N, T-P and Si), the coast of Dokdo was estimated to be more polluted than the previous results in 2000. A total of 72 species in Dokdo were composed of 54 species (76.1%) for Bacillariophyceae and 13 species (18.3%) for Dinophyceae, 3 species (4.2%) for Chrysophyceae and 1 species (1.4%) for Cyanophyceae. The standing crops of phytoplankton were the highest (8.5 $\times$ 10$^4$ cells L$^{-1}$) at 20 m of station DOK1, while they were the lowest (1.65 $\times$ 10$^4$ cells L$^{-1}$) at 30 m of station 1. The dominance index was maximum (0.73) at 10 m of station DOK1 and was minimum (0.4) at 30 m of station 1. The diversity index was the highest (2.92) in the surface of station 2, while it was the lowest at 20 m (1.58). The dominant species of phytoplankton were Chaetoceros affinis (3.3 $\times$ 10$^4$ cells L$^{-1}$) at 20 m, Climacosphenia moniligera (2.8 $\times$ 10$^4$ cells L$^{-1}$) at 40 m and Melosira juergensii (1.7 $\times$ 10$^4$ cells L$^{-1}$) at 10 m of station DOK1. At the surface of station DOK2, the dominant species were Bacillaria paxillifer and Richelia intracellularis (1.4 $\times$ 10$^4$ cells L$^{-1}$, respectively), while it was Paralia sulcata (1.6 $\times$ 10$^4$ cells L$^{-1}$) at the surface of station DOK3. The station DOKl, where affected by upwelling, turbulence and convection due to the East Korean Warm Current, was the most eutrophicated water body in three stations. The monitoring of marine ecosystem in the coast of Dokdo should be continued to show the alternatives for water and species conservation and to purify the eutrophicated water body due to artificial pollutants as well as physico-chemical factors by the global warming, the climatic change, CO$_2$ etc.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.26 no.4
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• pp.356-368
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• 2021

To understand the temporal variation of phytoplankton communities in a coastal area, the biomass and diversity were weekly investigated in the inner bay of Yeong-do, Busan. In the study area, chlorophyll a concentration ranged from 0.43~7.58 mg m^-3 during the study, indicating the study area was in mesotrophic or eutrophic status. The fractions of chlorophyll a occupied by large phytoplankton (> 3 ㎛ diameter) exhibited an average of 80% of total chlorophyll a in this study. Among the large phytoplankton, while Bacillariophyta was the most dominant in spring and summer, Cryptophyceae prevailed in the fall and winter. On the contrary, in the picophytoplankton community less than 3 ㎛ in diameter, Mamiellophyceae was the most dominant in most seasons, Cryptophyceae was relatively high with an average of 17.7 ± 17.6% throughout the year, but seasonal variations were large. Dinophyceae rarely occupied a higher fraction up to 60.4% of the picophytoplankton community. By weekly monitoring at a coastal station for 13 months, it is suggested that phytoplankton communities in coastal waters could be changed on a short time scale. If data are steadily accumulated at the time-series monitoring site for a long time, these will provide important data for understanding the long-term dynamics of phytoplankton as well as the impact of climate and environmental changes.

• Journal of Wetlands Research
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• v.14 no.3
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• pp.419-428
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• 2012

Taxonomic identification of phytoplankton has been a difficult task, even for the experienced taxonomist. Many non-descript, yet abundant, phytoplanktons do exist without distinguishing features which cause difficulties in morphological identification. Using PCR(polymerase chain reaction)-DGGE(denaturing gradient gel electrophoresis)method, which is known to be a powerfulfingerprinting technique to analyze diversity and dynamics of microbial populations, this study aimed to find the way to overcome the limitation of morphological identification. As a result, a total of 46 bands from samples in five lakes were detected in September and 27 bands in November. Fingerprinting results showed convenient and comparative analyses among each sampling site. In this study, PCR-DGGE method was used to figure out diversity and dynamics of plankton community in the lakes of North-Han River system. Also, the possibility of DGGE technique as an identification tool for phytoplankton was estimated.

• ALGAE
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• v.34 no.2
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• pp.99-109
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• 2019

Habitat-forming species increase spatial complexity and alter local environmental conditions, often facilitating the assembly of plants and animals. We conducted a trait-based approach to algal assemblages associated with the freshwater bryozoan, Pectinatella magnifica. Association with algae leads to the inner bodies of the bryozoans being colored green; this is frequently observed in the large rivers of South Korea. We collected the green-colored gelatinous matrices and phytoplankton from waterbodies of the two main rivers in South Korea. Algal assemblages within the colonies and in the waterbodies were compared using the three diversity indices (richness, diversity, and dominance), and the composition of functional groups (FGs) and morphologically based functional groups (MBFGs) between the colonies within and outside of P. magnifica colonies. The most dominant and common species within the colonies were Oscillatoria kawamurae and Pseudanabaena catenata, both of which were assigned to the same FG (codon S1). Of the algal assemblages within the colonies, the dominance was higher, while the richness and diversity were lower, than those in the waterbodies. There was variation in the compositions of FGs and MBFGs in the waterbodies outside the colonies. Total nitrogen and orthophosphate led to dominance, and were significant factors for the variation in FGs in the waterbodies, whereas there were no such significant factors within the colonies. This trait-based approach to the community structure of associated algae provides the status and habitat gradient of these communities, which are stable, isolated, and consistent with the overgrowth of shade-adapted tychoplanktonic cyanobacteria.

• Journal of Wetlands Research
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• v.14 no.3
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• pp.429-438
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• 2012

Han River is very important as a source of drinking water in metropolitan area. This study was conducted to figure out diversity and dynamics of plankton community in the seven lakes (lakes Paro, Chunchon, Soyang, Uiam, Chungpyung, Paldang, Chungju) of Han Riversystem. A total of 76 genera and 121 species were investigated by taxonomic identification in November 2008. Cyclotella sp. and Microcystis sp. was a dominant species in lake Paro and Chungju respectively. Aulacoseira granulata was dominant in lakes Chunchon, Paldang and Chungpyung. And Fragilalia crotonesis was a dominant species in lake Soyang and Uiam. Our results can be useful when compared to the results using molecular biological method to supplement taxonomic identification.

• ALGAE
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• v.36 no.3
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• pp.195-206
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• 2021

Increasing inputs of dissolved organic matter (DOM) to northern lakes is resulting in 'lake browning.' Lake browning profoundly affects phytoplankton community composition by modifying two important environmental drivers-light and nutrients. The impact of increased DOM on native isolates of red and green-pigmented cyanobacteria identified as Pseudanabaena, which emerged from a Dolichospermum bloom (Dickson Lake, Algonquin Provincial Park, Ontario, Canada) in 2015, were examined under controlled laboratory conditions. The genomes were sequenced to identify phylogenetic relatedness and physiological similarities, and the physical and chemical effects of increased DOM on cellular performance and competitiveness were assessed. Our study findings were that the isolated red and green phenotypes are two distinct species belonging to the genus Pseudanabaena; that both isolates remained physiologically unaffected when grown independently under defined DOM regimes; and that neither red nor green phenotype achieved a competitive advantage when grown together under defined DOM regimes. While photosynthetic pigment diversity among phytoplankton offers niche-differentiation opportunities, the results of this study illustrate the coexistence of two distinct photosynthetic pigment phenotypes under increasing DOM conditions.