• ALGAE
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• v.21 no.4
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• pp.377-392
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• 2006

Seventy eight taxa of Bacillariophyceae belonging to 1 species of Aulacoseira, 1 species of Cyclotella, 1 species of Tabellaria, 1species of Diatoma, 1 species of Thallasionema, 1 species of Grammatophora, 1 species of Fragilaria, 8 species of Synedra, 2 species of Achnanthes, 1 species of Cocconeis, 1 species of Diadesmis, 1 species of Diplonies, 2 species of Gyrosigma, 3 species of Pleurosigma, 15 species of Navicula, 4 species of Pinnularia, 3 species of Stauroneis, 1 species of Eunotia, 2 species of Himantidium, 11 species Gomphonema, 5 species of Cymbella, 1 species of Cocconema, 4 species of Amphora, 1 species of Rhopalodia, 5 species of Nitzschia and 1 species of Surirella were reported from different fresh water habitats of Orissa state and its neighbouring regions of India. All the taxa were recorded for the first time from this region.

• Fisheries and Aquatic Sciences
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• v.3 no.2
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• pp.151-155
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• 2000

Phaeodactylum tricornutum (Bacillariophyceae) is a marine diatom which has been supplied as a food of bivalves. In this study, growth responses of P. tricornutum to some nitrogen sources and sodium were investigated by measuring cell number and contents of chlorophyll a in culture. In medium with nitrogen and sodium, brisk cell division occurred and maximum growth rate was respectively found in the medium with 150 mg/l of nitrate and 10 mg/l of ammonium and urea. At 10-500 mg/l ammonium and urea and 200-500 mg/l nitrate, specific growth rate decreased slightly. However, no cell division observed in sodium-deficient medium, regardless of presence or absence of nitrogen. This suggests that sodium is required for the nitrogen uptake of P. tricornutum, resulting nitrogen uptake leading to cell division. Also the upper limits of ammonium and nitrate for the growth of P. tricornutum seem to be 10 mg/l and 500 mg/l, respectively.

• ALGAE
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• v.18 no.2
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• pp.145-156
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• 2003

Seasonal investigations were conducted to determine the major aquatic environmental factors and the variation of phytoplankton in Pyeongtaek Reservoir in March, June, September, and December 2000. Heavy rainfall mainly occurs from late June to mid-September, and water quality of reservoir was high in the influent zone of stream and riverine zone of reservoir. The biomass of phytoplankton was related to aquatic environmental factors. In particular, its value increased where nutrient concentration was high. Likewise, the increase of turbidity was found to have anthropogenic effects on the varying quantity of phytoplankton. The phytoplankton composition in quantitative survey identified into 43 genera and 71 species. Species numbers of Bacillariophyceae, Cyanophyceae, and Chlorophyceae accounted for 17%, 15%, and 49%, respectively, with the remainder constituting less than 3-7%. The distribution of such phyla also significantly varied according to seasons, accounting for 25%, 37%, 61%, and 14% in March, June, September, and December, respectively. Bacillariophyceae and Chlorophyceae were observed throughout the year, while Cyanophyceae proliferated in June and September. Euglenophyceae and Dinophyceae were prevalent in March and September, while Cryptophyceae occurred in March and December. The succession trend of phytoplankton showed the maximum cell density was followed by Bacillariophyceae (6.8$\times$$10^3$ cells ${\cdot}$ml)$\rightarrow$ Chlorophyceae (3.7$\times$$10^3$ cells ${\cdot}$ml)$\rightarrow$Cyanophyceae (1.3$\times$$10^4$ cells ${\cdot}$ml)$\rightarrow$Cryptophyceae (1.2$\times$$10^3$ cells ${\cdot}$ml). The cell density was the highest in the upstream. Dominant species were composed of Aulacoseira ambigua, Stephanodiscus hantzschii f. tenuis of Bacillariophyceae, Anabaena spiroides var. crassa, Microcystis aeruginosa, Oscillatoria amphibia of Cyanophyceae, Actinastrum hantzschii var. fluviatile, Pediastrum duplex var. reticulatum of Chlorophyceae, Euglena gracilis, Trachelomonas spp. of Euglenophyceae, and Chroomonas spp., Cryptomonas spp. of Cryptophyceae. As a results, seasonal variation of phytoplankton in Pyeongtaek Reservoir was evident in spite of inflow the high concentration of nutrients from watershed streams, because hydrological control and anthropogenic disturbance in reservoir were found to have major effects on the retention time of water.

• Journal of Environmental Science International
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• v.21 no.11
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• pp.1349-1360
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• 2012

This study presented the phytoplankton communities of the three lakes (Sayeon, Daeam, Hoeya ) using for drinking water in the Ulsan reservoir. The water storage of the Lake Sayeon, Daeam and Hoeya were 25, 13, 21 million ton respectively and most of which were being utilized for industrial and residential purposes. The total precipitation of the Ulsan region in 2010 was 1,162 mm, decreasing 10 % from 1,275 mm of the annual. As for pollutant loads, BOD and TN discharge loads of Daeam was the highest with 3,277 kg/day, 1,931 kg/day and 90 % of them were came from non-point pollutant sources. TP discharge loads showed the highest in the lake Hoeya with 643 kg/day and 97 % of them were came from point sources as household, industry and livestock. We assessed water quality of the lake Sayeon, Daeam and Hoeya using 17 variables. The water quality assessment found that the lake Daeam met the fourth to fifth grade because of high concentration of COD, SS and chlorophyll-a. Eutrophication assessment was conducted by revised Carlson's Index (TSIm, Aizaki) and found that Lake Daeam was more eutrophicated than the other two lakes all the year through as for chlorophyll-a, transparency and the total phosphorus (TP). A total of 95~111 phytoplankton species were identified from the three lake samples. Among them, the largest number of species were Chlorophyceae with 35~51, followed by Bacillariophyceae with 36~45, Cyanophyceae with 9~11, and Cryptophyceae with 6~9 species. The total cell number of phytoplankton was the highest in February (15,254 cells/mL) with Bacillariophyceae in the lake Daeam and the seasonal succession shows that Bacillariophyceae (Stephanodiscus spp.) in the spring, Cyanophyceae (Anabaena spp.) in the summer and the autumn, Bacillariophyceae (Stephanodiscus spp.) in the winter.

• Journal of Korean Society on Water Environment
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• v.26 no.4
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• pp.673-680
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• 2010

Environmental factors and phytoplankton community in Lake Doam were monthly investigated at 3 stations from April 2009 to November 2009. During the study period, the concentrated rainfalls occurred at between July and August and then the TP and turbidity were sharply increased in in-lake. A total of 91 phytoplankton species was classified and these were consisted of 38 Bacillariophyceae, 35 Chlorophyceae, 10 Cyanophyceae, and 8 other species. Bacillariophyceae and Chlorophyceae were dominated during the seasonal succession of phytoplankton community, especially summer season. Bacillariophyceae was dominated from spring season to summer season and Chlorophyceae was dominated at summer season and autumn season. However, the dominance of Cyanophyceae generally developed at summer season in eutrophic water was not observed. From the analysis of correlation coefficient between environmental factors and phytoplankton cell number, we confirmed that there was a negative correlation between turbidity and cyanobacteria cell number (P<0.01). This result indicated that turbid water acts as the inhibitor of the cyanobacteria growth than other phytoplankton community.

• ALGAE
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• v.17 no.2
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• pp.117-125
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• 2002

Five microalgal species isolated from the Jeju coast and four microalgal stock strains in hatchery were cultured in order to investigate their adapation to extreme changes in environmental factors such as salinity, water temperatue, adn nutrients. In case of salinity variation, Nitzschia sp. of Bacillariophyceae, Isochrysis galbana of Haptophyceae and Tetraselmis gracilis of Prasinophyceae showed optimum growth at the low salinity of 20 and 25 psu. Amphora coffeaeformis and Chetoceros simplex of Bacillariophyceae, and Pavlova lutheri of Haptophyceae adapted well at the relatively high salinities of 30 and 35 psu. However Phaeodactylum tricornutum of Bacillariophyceae and Chlorella sp. of Chlorophyceae showed euryhaline property In case of water temperature variation, most of all the species studied wer inhibited at 10℃. C. simplex, Nitzschia sp., p. tricornutum, Chlorella sp. and T. gracilis grew well at above 20℃. A. coffeaeformis, I. galbana and P. lutheri adapted also at the high temperature of 30℃. Each microalgal strain showed different growth rates and its maximum biomass. Generally microalgal populations from the Jeju coast grow well in relatively high salinity and high water temperature. Their growth were inhibited at low water temperature, but not likely affected at low salinity. This study indicates that the microalgal populations could not be affected by abnormally low salinity phenomena, which have happened occasionally around the west Jeju coast in summer and have led macrobenthic animals to mass mortality.

• ALGAE
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• v.20 no.1
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• pp.43-52
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• 2005

A study on the seasonal changes in the phytoplankton community was carried out in four aquaculture ponds of Bangladesh over a period of 16 months from August 2000 to November 2001. Out of 45 phytoplankton species identified, 30 belong to Cyanophyceae, 7 to Chlorophyceae, 5 to Bacillariophyceae and 3 to Euglenophyceae. The highest phytoplankton abundance was observed in spring followed by early autumn, summer, and the lowest was in winter. The annual succession of Cyanophyceae was characterized by spring and early autumn period dominated by Microcystis sp. Anabaena sp. and Planktolymbya sp. with Microcystis sp. as the main blue-green algae represented. Chlorophyceae was characterized by rainy season domination of Chlorella vulgaris, Pediastrum sp. and Scenedesmus denticulatus with maximum abundance of Chlorella vulgaris. Whereas Bacillariophyceae was dominant during the winter period. Navicula angusta and Cyclotella meneghiniana were the most frequently occurring species of Bacillariophyceae throughout the study period. Euglenophyceae was dominant in late autumn and Euglena sp. was the dominant species. The effect of various physicochemical water quality parameters on the seasonal distribution and succession of the above mentioned phytoplankton population as well as the interaction and eutrophication are discussed.

• Korean Journal of Ecology and Environment
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• v.41 no.2
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• pp.128-136
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• 2008

An attempt was made in the Veeranam freshwater lake with the objectives to collect, identify, describe and document the algae occurring from March 2007 to August 2007. Qualitative and quantitative characterization of phytoplankton and analysis of physico-chemical parameters of water samples were carried out at monthly intervals during the study period in the western and eastern sides of the lake. It was found that the phytoplankton community embraced 68 genera belonging to four classes viz., Bacillariophyceae (40), Chlorophyceae (22), Cynophyceae (4) and Euglenophyceae (2). There were significant influences of various physico-chemical parameters on the phytoplankton population density. Commonly occurred genera, Oscillatoria (Cyanophyceae), Navicula (Bacillariophyceae) and Scenedesmus (Chlorophyceae), were subjected to energy dispersive spectroscopic analysis (EDS). They were found to accumulate different elements such as Zn, P, S, Ca, Mg, Fe, N, Si, Cl and Mn. Among these the member Cyanophyceae contained Zn, P, Mg, Ca, Mn, S and N. Bacillariophyceae Si, Zn, Mg, Cl, N, Fe, and Ca. Chlorophyceae Ca, Mg, N, Fe, Cl, Zn, Si and Mn. Thus these observations would determine the chemical dialogue between the cell structures and role of the elements. Further, it gives the clue about the phytoplankton growth requirements.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.367-376
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• 2008

The seasonality of phytoplankton in Dongbok lake was analysed from March to November 2003. The concentrations of TN and TP showed nearly constant level except high concentrations in May at dam site of Dongbok lake. Chlorophyll ${\alpha}$ concentration was highest at dam site in May with 225.3 ${\mu}g$ L$^{-1}$ and high in spring and fall and low in summer at upper and central regions of Dongbok lake. A total of 108 phytoplankton species was identified as an algal flora of Dongbok lake. They were 54 Chlorophyceae, 30 Bacillariophyceae, 12 Cyanophyceae, and 12 species of other taxa. Total cell biomass of phytoplankton showed peaks in May$\sim$June and August$\sim$September, and low biomass in July at dam site. However, upper and central regions of Dongbok lake showed no clear patterns in cell biomass. Maximum biomass was 7,158 cells mL$^{-1}$ at dam site in May with the blooms of Peridinium bipes f. occulatum. The general seasonality of phytoplankton in Dongbok lake was Bacillariophyceae-Dinophyceae/Bacillariophyceae-Cyanophyceae/Chlorophyceae/Bacillariophyceae-Bacillariophyceae in 2003.

• Journal of Ecology and Environment
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• v.36 no.4
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• pp.391-406
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• 2013

A study on the fine structure of the genus Achnanthes species (Bacillariophyceae) is carried out at 92 stations for taxonomic purposes from January 2009 to April 2013 in Korean marine water, freshwater and brackish water. Twelve Achnanthes species are identified based on a variety of taxonomic characters by means of light microscopy and scanning electron microscopy. Of these, seven species, Achnanthes cocconeioides, A. groenlandica, A. javanica, A. kuwaitensis, A. parvula, A. pseudolongipes, and A. yaquinensis, are newly recorded in Korean waters. All 12 species are documented concerning a taxonomic key, description, distribution, seasonality, remarks and photographs. Twenty three Achnanthes taxa are identified in the survey.