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

• Proceedings of the Zoological Society Korea Conference
• /
• 2000.10a
• /
• pp.145.2-146
• /
• 2000

No Abstract, See Full Text

• Journal of Environmental Science International
• /
• v.19 no.11
• /
• pp.1445-1456
• /
• 2010

This study presented seasonal changes of the phytoplankton community in Junam reservoir by pollution and water quality of the lake. The water storage of the reservoir is 5.3 million ton, most of which are being utilized for agricultural, industrial and residential purposes. The annual precipitation during the investigation period was 1,868.9 mm, increasing by 20% from the average annual level of 1,506.7 mm in 2009. The annual average water storage was 57.3%. It decreased during agricultural season and then increased again after monsoon rainfall. The loads of BOD were $3,799kgday^{-1}$, and 81% of them came from livestock and household. The TN and TP loads were $1,164kgday^{-1}$ and $170kgday^{-1}$, respectively, and 76% of them came from livestock. We assessed water quality of the Junam reservoir using 17 variables. According to the result, the reservoir met the fourth grade, meaning slightly bad, because of high concentration of COD, SS and chlorophyll-a. Eutrophication assessment was conducted by revised Carlson's Index (TSIm, Aizaki), and it was found that the entire lake was eutrophicated with high chlorophyll-a concentration all through the year, except during February to April and in July. A total of 76 phytoplankton species were identified from the samples. Among them, the largest number of species were Chlorophyceae with 33 species(43.4%), followed by Bacilliophyceae with 27 species(35.5%), Cyanophyceae with 8 species(10.5%), and Cryptophyceae with species(10.5%). The total cell number of phytoplankton was the highest in October(7,884 cells $mL^{-1}$) among Cyanophyceae and Bacilliophyceae. The seasonal succession of Chlorophyceae (Chlamydomonas spp.), Cyanophyceae(Microcystis aeruginosa) and Cryptophyceae(Rhodomonas spp.) was observed during January to May, July to September and October to December respectively.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
• /
• v.16 no.4
• /
• pp.238-245
• /
• 2011

Phytoplankton community composition was investigated in the Asan Bay (South) Korea. Water samples were collected monthly from five stations during January to December 2008. Phytoplankton blooms were observed in February and in August but the location of the bloom varied with the sampling time. A total of 134 phytoplankton species from seven classes (Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae) were observed. Diatoms were dominant in all stations through-out the year except in summer when dinoflagellates were numerous and highly distributed within the outer bay rather than in the river mouth. Dominant and subdominant species were composed mostly of diatoms but were replaced by dinoflagellates in June and July. Results of ecological index showed that the diversity indices were increasing toward outer bay but the dominance indices showed a reverse trend.

• ALGAE
• /
• v.18 no.4
• /
• pp.273-280
• /
• 2003

The physico-chemical characteristics and seasonal variations of phytoplankton community were investigated in the Paksil and Jungyang marshes. Water and phytoplankton samples for analyses were collected monthly from April 2002 to March 2003. A total of 421 taxa of phytoplankton belonging to eight classes identified. The number of taxa was highest in Bacillariophyceae, followed by Chlorophyceae, Euglenophyceae, Cyanophyceae, Chrysophyceae, Dinophyceae, Xanthophyceae and Cryptophyceae. The standing crops ranged from 1.25 ${\times}$ $10^6$ to 5.85 ${\times}$ $10^6$ cells ${\cdot}l^{-1}$ in Paksil marsh and 0.25 to 9.63 ${\times}$ $10^6$ cells ${\cdot}l^{-1}$ in Jungyang marsh. The highest algal density at Paksil marsh was recorded in October during the high development of Chlorococcales while the lowest value occured in July. In the Jungyang marsh, the maximum algal density was recorded in October when Cryptomonas sp. and Mallomonas sp. accounted for 64% to total cell numbers and the lowest cell density was observed in January due to the decrease of Chlorophyceae. The dominant species were represented by Euglena proxima, Trachelomonas oblonga, Trachelomonas volvocina of Euglenophyceae, Dictyosphaerium pulchellum, Monoraphidium griffithii, Oocystis parva of Chlorophyceae, Dinobryon sertularia, Kephyrion rubri-claustri of Chrysophyceae, Achnanthes minutissima of Bacillariophyceae and Cryptomonas sp. of Cryptophyceae in the Paksil and Jungyang marshes. Phytoplankton diversity(H’) and dominance index varied rather irregularly throughout the sampling period but they were significantly correlated. The highest diversity(H’Paksil = 3.68, H’Jungyang = 3.63) coincided with the lowest values of dominance(DPaksil = 0.05, DJungyang = 0.05)

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

• Proceedings of the Korean Environmental Sciences Society Conference
• /
• 2000.05a
• /
• pp.243-244
• /
• 2000

낙동강 중류에서 조사된 식물플랑크톤상은 7강 42속 77종류였고 Bacillariophyceae가 43종류(55.8%), Chlorophyceae 24종류(31.2%), Cyanophyceae 4종류(5.2%), Dinophyceae와 Euglenophyceae이 각각 2종류(2.6%), Chrysophyceae와 Cryptophyceae가 각각 1종류 (1.3%)였다. 주요종은 Stephanodiscus hantzschii를 비롯한 6속 7종류였고 모두 규조류였다. 현존량은 최저 79 cells/$m{\ell}$(3월, 고령)에서 최고 33,023 cells/$m{\ell}$(2월, 물금)로 나타났다. 우점도지수는 최저 0.434(8월, 남지), 최고 0.999(1월, 2월, 물금)였다. 종다양성지수는 최저 0.026(2월, 물금), 최고 3.073(9월, 남지)로 조사되었다.

• ALGAE
• /
• v.22 no.3
• /
• pp.147-152
• /
• 2007

We described two brownish freshwater Cryptomonas species, C. marssonii Skuja and C. pyrenoidifera Geitler as first records in Korea. The identification was based on light microscopy, scanning electron microscopy, and nuclear SSU rDNA sequences analysis. Cryptomonas marssonii is characterized by its sigmoid shape with a sharply pointed and dorsally curved antapex, dorso-ventrally flattened cell, two lateral plastids without pyrenoid, and its dimension of 18-25 μm in length and 8-13 μm in width. Cryptomonas pyrenoidifera is characterized by ovoid to elliptical shape with a partially twisted or rounded antapex, dorso-ventrally biconvex cell, lateral plastids with two pyrenoids, and the dimensions of 15-22 μm in length and 10-14 μm in width. Nuclear SSU rDNA sequences between C. marssonii WCK01 from Korea and CCAC0086 from Gernmay, and between C. pyrenoidifera WCK02 from Korea and CCMP152 from Australia were identical, respectively.

• Korean Journal of Environmental Biology
• /
• v.39 no.4
• /
• pp.435-444
• /
• 2021

The genus Chroomonas is a group of blue-green colored cryptomonads. This study describes two freshwater Chroomonas species for the first time in South Korea: Chroomonas nordstedtii Hansgirg and Chroomonas coerulea (Geitler) Skuja. We examined the morphology and ultrastructure of these species by light microscopy, scanning electron microscopy, and transmission electron microscopy. These two Chroomonas species were blue-green colored and ovate to oval-shaped. Chroomonas nordstedtii was characterized by two Maupas ovals with hexagonal periplast plates, whereas C. coerulea was characterized by one eyespot with rectangular periplast plates. A molecular phylogeny with data from nuclear SSU rRNA and chloroplast rbcL genes revealed that Korean C. nordstedtii formed a distinct clade with NIES-708, NIES-1004 from Japan, and UTEX 2779 from Colorado, USA, while C. coerulea formed a clade with ACOI 1366 from Portugal.

• Fisheries and Aquatic Sciences
• /
• v.26 no.7
• /
• pp.423-436
• /
• 2023

The objectives of this review were to synthesize the community structure of phytoplankton and the role of atelomix in the phytoplankton dynamics in Ethiopian highland lakes. Changes in a lake's physical structure, light dynamics, and availability of nutrients are closely associated with phytoplankton ecology, and phytoplankton assemblages provide insight into phytoplank- ton responses to these environmental changes. Based on the available information, a total of 173 species of phytoplankton are grouped under seven classes, Chlorophyceae (80 taxa), Bacillariophyceae (55 taxa), Cyanophyceae (24 taxa), Dinophyceae (6 taxa), Eugleonophyceae (6 taxa), Xanthophyceae (1 taxon), and Cryptophyceae (1 taxon) were recorded in five different tropical Ethiopian highland lakes. Chlorophyceae and Bacillariophyceae dominated in terms of species composition. Partial atelomixis, seasonality, and low nutrient concentrations seem to be the main drivers in structuring phytoplankton composition and abun-dances in Ethiopian highland lakes, characterized by a high diversity of atelomix-dependent benthic diatoms and desmids. Thus, this review will help understand the role of atelomix and nutrient availability in the phytoplankton composition and biomass of tropical highland lakes of Ethiopia.