• Journal of Plant Biology
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• 제29권2호
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• pp.117-127
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• 1986

Phytoplankton community was investigated at the Paldang Dam Reservoir in the Mid-Han River by it's depth, in spring and summer known as the period of phytoplankton's blooming. It was only in summer that phytoplankton bloomed at the investigated area. 128 kinds of phytoplankton were identified and of them, diatoms were abundunt in spring but cyanophyta and chlorophyta were in summer. Because some species with high pollution index were observed in summer, it could be proved that the investigated area was polluted especially in summer. In spring shown the circulation period by vertical distribution pattern of chlorophyll-a and isothermal distribution pattern of water temperature, maximum value of phytoplankton standing crops appeared at the upper layer, except for surface layer. In summer shown the circulation period after the stagnation period by vertical distribution pattern of chlorophyll-a and immediate destruction after stratification of water temperature, maximum value of phytoplankton standing crops appeared at the lower layer. the layer at which the maximum value of chlorophyll-a appeared also accorded with that of phytoplankton standing crops. So, it could be approved that there existed a close relationship among phytoplankton standing crops, chlorophyll-a, and water temperature.

• 환경생물
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• 제36권1호
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• pp.62-72
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• 2018

진주만 해역에서의 식물플랑크톤 시공간적 군집 분포와이를 조절하는 환경요인을 파악하기 위해 물리, 화학적인 환경조사와 더불어 UPLC-CHEMTAX program을 이용한 식물플랑크톤 군집특성분석을 수행하였다. 본 연구해역에서의 Chlorophyll ${\alpha}$ 농도는 평균 $1.84{\mu}gL^{-1}$ ($0.13{\sim}9.03{\mu}gL^{-1}$)로 얕은 수심과 조석의 혼합이 활발한 본 연구해역에서 겨울철 식물플랑크톤 현존량이 높게 나타났다. 또한 본 연구해역에서 나타난 주요 식물플랑크톤 군집 중 규조류가 연구기간 동안 평균 77.1%로 대부분 우점하였으나, 하계 (6월, 7월, 8월) 은편모류 (7.7~18.8%), 담녹조류 (7.8~17.3%), 와편모류 (4.9~13.9%)의 분포비율을 나타내었다. 특히 은편모류와 담녹조류는 현미경으로 검경하기 어려운 군집이며, 동기간 보고된 현미경 관찰결과에도 나타나지 않아 향후 이들 군집에 대한 면밀한 조사가 필요할 것으로 판단되었다. 본 연구를 통해 UPLC 활용하여 진주만 어장 생태계의 기초 생산자이자 먹이원으로 작용하는 식물플랑크톤의 생물량 및 시공간적 변동특성을 확인할 수 있었다. 아울러 현미경 검경으로 확인하기 어려운 은편모류와 담녹조류 군집이 하계에 상대적으로 높은 비율을 나타내는 것을 UPLC로 확인할 수 있었고, 이러한 결과는 향후 1차 생산에 관여하는 식물플랑크톤의 계절 변화의 기초정보로 유용하게 이용될 것이다.

• ALGAE
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• 제21권1호
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• pp.83-90
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• 2006

Phytoplankton community in the coastal waters off the northeastern Korean Peninsula were characterized from May 2002 to August 2003. Taxonomic composition, abundance and biomass were determined at two water depths at 10 sample sites. A total of 153 phytoplankton species including 121 diatoms, 28 dinoflagellates, 7 green algae and 7 other species were identified. The mean abundance of phytoplankton varied from 15 to 430 cells mL–1 in the surface layer and from 11 to 545 cells mL–1 in the bottom layer, respectively. Phytoplankton was more abundant in coastal stations relative to those in more open ocean. The most dominant species were marine diatoms such as Thalassionema nitzschioides, Licmorphora abbreviata, Chaetoceros affinis and Chaetoceros socialis. In addition, a few limnotic diatoms including Fragilaria capucina v. rumpens, the green alga Scenedesmus dimorphus, some marine dinoflagellates and Cryptomonas sp. appeared as dominant species. Mean concentration of total chlorophyll-a varied from 0.22 to 7.87 μg chl-a L–1 and from 0.45 to 6.79 μg chl-a L–1 in the surface and bottom layers, respectively. The contribution of phytoplankton each size-fractionated varied highly with season. The contribution of microphytoplankton to total biomass of phytoplankton in the surface and bottom layer was high in February and August 2003, and that of nano-phytoplankton was high in May 2002 in both surface and bottom layers.

• Ocean and Polar Research
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• 제41권1호
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• pp.1-10
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• 2019

Right after the 2007 Hebei Spirit Oil Spill phytoplankton ecosystems were investigated for 11 years based on the seasonal monitoring of the composition and abundance of phytoplankton species. Comparable time-series data from the 1989 Exxon Valdez or the 2010 Deepwater Horizon Oil Spill sites were not available. It was suggested that the ecological healthiness of phytoplankton ecosystems at EVOS sites had recovered after 10 years following the oil spill based on chlorophyll concentrations even though these concentrations only represented phytoplankton communities in most cases. Chlorophyll concentrations can only reflect limited aspects of highly complex phytoplankton ecosystems. During the last 11 years following the 2017 HSOS, extreme variabilities were met in the seasonally averaged ratios of diatoms to phototrophic flagellates including dinoflagellates based on the microscopic cell countings. Summer phytoplankton communities exhibited some cyclic interannual changes in dominant groups every 2-4 years. During the early years (2008-2010) cryptophytes or raphidophytes (Chattonella spp.) dominated alternately each year, which was repeated again in 2014, 2015 and 2017. Two thecate dinoflagellates, Tripos fusus and Tripos furca, together accounted for 52.5% and 50.0% of all organisms in the summers of 2011 and 2012, respectively, which was repeated again in 2018. Summer occurrence and dominance by the phototrophic flagellates including HABs (Harmful Algal Blooms) species as well as their interannual variabilities in the oil spill sites could be utilized as markers for the stable and long-term management of healthy ecosystems. For this type of scientific ecosystem management monitoring of chlorophyll concentrations may sometimes be insufficient to gain a proper and comprehensive understanding of phytoplankton communities located in areas where oil spills have occurred and harmed the ecosystem.

• The Korean Journal of Ecology
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• 제23권4호
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• pp.299-307
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• 2000

To understand the mechanism of phytoplankton succession in the Nakdong River, the resource availability (silica) and grazing effect on the phytoplankton community were investigated in an enclosure experiment at Mulgum in March 1995. In all enclosures, Stephanodiscus hantzchii was dominant during the first week. Two weeks later, the diatom community in the A (river water only) and B (filtered river water) enclosures was shifted to colonial green algae (Actinastrum sp., Pediastrum spp. and Scenedesmus spp.) and nanoplankton (2~3 ${\mu}$m of diameter) due to the silica depletion. In the C (silica addition in river water, 3 mg 1$^{-1}$ week$^{-1}$) and D (silica addition in filtered water) enclosures, Fragilaria crotonensis and Synedra acus increased as the silica addition was continued. The percentage of small phytoplankton (size, 10~13 ${\mu}$m) in the filtered enclosures (B and D) was much higher than that of A and C enclosures. A laboratory bottle experiment conducted in the fall of 1994 also showed similar results. Therefore, it is concluded that silica and zooplankton are important regulators in phytoplankton succession during the diatom blooming season in the Nakdong River.

• Ocean and Polar Research
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• 제40권4호
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• pp.191-202
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• 2018

In this study we conducted a weekly monitoring exercise at a fixed station in the saltwater zone during the dry season (Jan-Mar, 2013) and wet season (Jun-Aug, 2013) to understand the fluctuations in phytoplankton communities and environmental factors in the Youngsan River estuary altered by a dike constructed in the coastal area. Phytoplankton communities displayed seasonality; diatoms were dominant during the dry season whereas dinoflagellates were dominant during the wet season. T-test analysis showed that water temperature was significantly different between the seasons whereas freshwater discharge from the dike was not significantly different. This suggests that seasonal variations of phytoplankton are more likely affected by water temperature than freshwater discharge. However, a short-term fluctuation was also observed in response to freshwater discharge; freshwater species appeared during or after the discharge in the dry and wet seasons and blooms of harmful species developed after the discharge. Phytoplankton communities may be affected by changes in physical factors such as turbidity and salinity and nutrient supply resulting from freshwater discharge. Especially, the nutrient supply may directly contribute to the harmful algal blooms (HABs) composed of dinoflagellates which can adapt to low salinity after freshwater discharge.

• 환경생물
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• 제21권1호
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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.

• Fisheries and Aquatic Sciences
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• 제26권7호
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• pp.423-436
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• 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.

• 한국환경과학회지
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• 제21권3호
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• pp.313-326
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• 2012

Three embankments, namely Changpo, Bokkil and Guil, in Chunggye Bay were investigated to assess the influence of environmental changes to phytoplankton size structure, distribution of species and standing crops. Three stations was sampled near at each embankment in Nov. 2006, Feb. 2007, May 2007 and Aug. Phytoplankton were classified into net-size (>20${\mu}m$) and nano-size (<20${\mu}m$). In summer, the freshwater discharge seemed to have influence in the decrease of salinity and in the increase of turbidity, ammonium and phosphorus concentrations. Chl a concentration and phytoplankton abundance in Feb. 2007 were observed to be generally higher in all stations compared to other periods. Net-size phytoplankton was observed to be higher in Feb. 2007 and May 2007 compared to nano-sized phytoplankton. However, there was shift in phytoplankton composition in Nov. 2006 and Aug. 2007. Phytoplankton under seven class (Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae) was identified during the study period. It was found out that the major phytoplankton class was Bacillariophyceae. Phytoplankton was more diverse in autumn compared to any other season. Cyanophyceae was increased in summer. In rainy season, change in physical factors (salinity, transparency) seemed to have more influence on phytoplankton growth compared to inorganic nutrients.

• ALGAE
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• 제17권4호
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• pp.267-273
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• 2002