• 한국해양학회지
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• v.1 no.1_2
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• pp.14-21
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• 1966

A phytoplankton study in the Korean waters has been commenced from 1964 as parts of the primary production studies in the Korean waters and the cruise for the cooperative studies of the Kuroshio from 1965 to 1968. Samples are taken by dipping 300-500 ml of sea water from the surface, and then fixed by adding neutralized formalin. The phytoplankton identification and cell counts are made on samples carefully after concentrated by decanting and centrifuging in the laboratory. This report deals with the surface phytoplankton obtained during the period of August 14-27, 1965 at twenty-three stations in the Korea Strait. Fifty nine species in seventeen genera of diatoms are detected from the samples collected at the stations. Among them seven species in five genera are considered to be purely neritic or cold water species and eight species in four genera are oceanic species of the Kuroshio. The highest phytoplankton standing crops are found in the sea area neighboring coastal waters of southern Korea, and the species distribution show anomalies in normally oceanic species being confined to neritic waters. There are distinct genera compositions of eastern, western and intermediate sea areas in the Kore Strait.

• ALGAE
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• v.19 no.4
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• pp.321-327
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• 2004

The literature review on the dynamics of the phytoplankton communities in terms of species composition, standing crops, abundant species and dominant species in the lower part of the Han River from 1940s to 2000s was conducted for the prospective prediction of their succession patterns. Total of 326 taxa were identified and they belonged to 47 blue-green algae, 139 green algae, 12 euglenoids, 126 diatoms, 6 din flagellates and 2 silicoflagellates. Composition of phytoplankton communities were 83.6% diatoms, 10.5% blue-green algae and 5.3% green algae in the middle of 1960s, whereas those were 43.2% diatoms, 40.7% green algae and 13.6% blue-green algae in the 1990s. Before 1990s, Synedra ulna, Melosira varians, Cymbella tumida, Synedra acus, Cymbella ventricosa, Navicula cryptocephala, Nitzschia palea, Aulacoseira granulata, Gomphonema parvulum and Cymbella affinis were most frequent, while those after 1990 were Asterionella formosa, Asterionella gracillima, Aulacoseira granulate, Aulacoseira granulata var. angustissima, Chlorella vulgare, Fragilaria crotonensis and Synedra ulna. Phytoplankton blooms were frequent from winter to the late spring and rare in summer due to heavy rain and discharge. Seasonal variations of the dominant species were fairly obvious; Asterionella gracillima and Aulacoseira granulata in spring, Aulacoseira granulate and Aulacoseira granulate var. angustissima in summer and autumn, Asterionella gracillima and Stephan discus hantzschii in winter. Recently blue-green algae, Microcystis, Aphanocapsa, Dactylococcopsis have been more abundant than those of the previous reports. Based on the current situations, Stephan discus hantzschii f. tennis, Asterionella gracillima, Aulacoseira granulate and blue-green algae will be more abundant and blooms of those species will be more frequent.

• Ocean and Polar Research
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• v.23 no.3
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• pp.245-253
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• 2001

To investigate the community structures and the their seasonal variation of phytoplankton and zooplankton, a study was conducted at 6 selected stations during the period from April 1999 to October 2000 in the marine ranching ground off Tongyeong. One hundred ninety species of phytoplankton were identified, including 146 diatoms, 38 dinoflagellates, 4 silicoflagellates and 2 euglenophytes. Phytoplankton standing crops varied extensively by months and stations, ranging from $3.0{\times}10^4\;cells/l\;to\;1.0{\times}10^6\;cells/l.$. The dominant species varied from the vertical distribution as well as seasonal changes. In April and July 1999, Skeletonema costatum and Ceratium fusus were predominant in both the surface and the bottom water columns. Leptocylindrus danicus was the dominant species in April and June 2000, and Thalassiosira spp. were also predominant in bottom waters in June 2000. Pseudonitzschia pungens and Chaetoceros spp. were the dominant species at both surface and near bottom waters in August and October 2000, respectively. Zooplankton abundance was comparatively high in April and July in 1999, and April, June, and October in 2000, but extremely low in November 1999. The density of dominant zooplankton was higher in 2000 than in 1999. Copepods were the most predominant group except for July 1999 when the bivalve larvae showed extremely high abundance. Acartia omorii and Oithona similis were the dominant or subdominant copepod species mainly in April 2000, and June/July, while O. davisae and O. plumifera had peaks in August and October 2000. Corycaeus affinis and Paracalanus sp. also showed higher peaks in April and June (or July), even though they occurred in all sampling time. Centropages abdominalis occurred abundantly only in April 1999. Oikopleura dioica, a gelatinous zooplankton, was another important zooplankton, showing high density in all samples except in July 1999.

• Journal of Environmental Science International
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• v.24 no.9
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• pp.1101-1121
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• 2015

The seasonal variation of phytoplankton communities and its standing crops in accordance with environmental factors were investigated at Yeongrang-ho, Cheongcho-ho, Mae-ho and Hyang-ho which are located in the East coast of Korea during April to October 2011. High concentrations of T-N and T-P were observed in four lagoons due to the inflowing nutrients from farmlands and residential areas near lagoons. Nutrient salts mainly composed of nitrogen and phosphate caused the eutrophication of the lakes, leading to the robust growth of phytoplankton. During the period of investigation, 64 to 107 taxa of phytoplankton were observed in four lagoons. Diatoms were the most dominant species with high density. Non-point pollution source was estimated as the main cause of water pollution of lagoons. Trophic states of lagoons evaluated using the value of TSI and TSIKO indicated that all the investigated lagoons were in the eutrophication state.

• Korean Journal of Ecology and Environment
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• v.38 no.3 s.113
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• pp.429-434
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• 2005

The dynamics of phytoplankton community after the formatiom of turbidity was assessed at Dam barrage of Lake Imha from May 2003 to July 2004. The maximum turbidity of 1221 NTU during September and October 2003 was well correlated with heavy precipitation caused by Typoon Maemi. A total of 102 phytoplankton taxa was identified and the most abundant phytoplankton group was Bacillariophyceae with 63 taxa, followed by Chlorophyceae with 23 taxa, Cyanophyceae with 9 taxa, 3 taxa each of Synurophyceae and Cryptophyceae and Euglenophyceae with 1 taxon. The total standing crops ranged between 270 indls. $mL^{-1}$ and 4,515 indls. $mL^{-1}$ during the investigation Periods. The three species, Cryptomonas ovata, Cyclotella sp. and Microcystis aeruginosa predominated in sequence after the decrease of turbidity.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.12 no.4
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• pp.305-314
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• 2007

We studied spatial and temporal distributions of the phytoplankton and their relationships to physico-chemical environmental factors in the western Jinhae Bay, Korea from November 2003 to August 2004. In most cases, physico-chemical environmental factors showed homogeneous distribution. The phytoplankton communities were composed of mainly diatoms and dinoflagellates, and their standing crops ranged from $16{\times}10^3\;cells\;l^{-1}\;to\;5,845{\times}10^3\;cells\;l^{-1}$ (with a mean value of $555{\times}10^3\;cells\;l^{-1}$). The bloom of phytoplankton was observed in Gohyun Port in the summer. Seasonal variation of phytoplankton standing crops was higher in winter and summer than in spring and autumn. The dominant species were Skeletonema costatum, Akashiwo sanguinea, Pseudo-nitzschia pungens, Dactyliosolen sp., Leptocylindrus danicus, cryptomonads and etc. Especially, S. costatum was predominant in the summer and A. sanguinea (spring and autumn), Pseudo-nitzschia sp. (summer), Guinardia striata (spring), unidentified flagellates (summer) and cryptomonads (spring) appeared to be an opportunistic species. Concentrations of Chl a ranged from $0.6{\mu}g{\cdot}l^{-1}\;to\;16.7{\mu}g{\cdot}l^{-1}$ (with a mean value of $3.4{\mu}g{\cdot}l^{-1}$). The results of the canonical correspondence analysis implies the study area was grouped into the 2 water masses (inner and outer waters of Gohyun Port) and inner waters had higher abundance and Chl a concentration than outer waters. Also, phytoplankton sanding crops were related with temperature, DO and nutrients ($SiO^2$, TN, TP and etc.) in inner waters. Inner water-mass of Gohyun Port expanded between Gacho Is. and Chilchon Is. during the winter.

• 한국해양학회지
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• v.25 no.4
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• pp.217-228
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• 1990

In order to study on the relative significance of nanoplankton in Chonsu Bay, nanoplankton samples were collected and analyzed monthly from September, 1985 to August, 1986. A total of 33 taxa representing 6 phyla, 8 classes, 13 orders, 17 families, 25 genera, 33 species have been identified. Micromonas pusilla, Pedinomonas mikron, Pyramimonas grosii, Chroomonas lateralis, Pyrenomonas salina (=Chromonas salina), chroomonas sp., Cyclotella sp., Gonyaulax sp., unidentified sphericl monads (2-5um and 6-8um in size), and unidentified naviculiod form were common species. the distribution of nanoplankton standing crops showed a great temporal and spartial variations. Nanoplankton standing crops was highest in October, 1985 and lowest in September, 1985. The abundance of nanoplankton in Chonsu Bay may be within the range of that of most coastal areas. Unidentified spherical monada (2-5um and 6-8um in size) were most dominant. Chlorophyll-a concentrations of nanoplankton ranged from 0.81 to 4.78ug/l and daily primary productivity by nanoplankton, 16.4 to 767.2 mgC/m$^2$/day. Nanofraction of total phytoplankton cell number accounted for 38% to 93% (average 6%), chlorophyll-a and primary productivity of nanoplankton 25 to 87% (average 64%) and 9 to 87% (average 53%), respectively. The results implied that nanoplankton could be a considerable contribution to phytoplankton biomass and primary productivity in Chonsu Bay phytoplankton community.

• Ocean and Polar Research
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• v.27 no.4
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• pp.359-379
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• 2005

In order to understand the spatial and temporal variations of nutrients and factors controlling their distribution in Gwangyang Bay, this study was carried out bimonthly from June 2001 to July 2003, Inorganic silicate and nitrate concentrations ranged from $0.04{\mu}M\;to\;69.5{\mu}M(avg.\;12.9{\mu}M)$, and from $0.12{\mu}M\;to\;42.2{\mu}M\;(avg.\;7.83{\mu}M)$, respectively. Silicate concentrations measured just after the typhoon were the highest with an average of $43.2{\mu}M$ at the surface layer in June 2001, whereas the highest nitrate concentration $(avg.\;37.0{\mu}M)$ was observed in the surface layer in July 2003. River runoff apparently influenced variations in silicate and nitrate concentrations (r=0.701 and 0.728, p<0.000, respectively) as well as salinity (r=-0.628, p<0.000). Phosphate concentrations ranged from $0.24{\mu}M\;to\;5.70{\mu}M\;(avg.\;1.34{\mu}M)$ and were highest at stations 5, 6, and 7, near a fertilizer plant with an average of $2.01{\mu}M$. On the basis of N/P and Si/N molar ratios, limiting nutrients have varied temporary and spatially. During 2001-2002, nitrogen was a limiting nutrient in the study area, and Phosphate was limited when a large volume of freshwater flowed into the bay. Silicate was limited when the high standing crops of phytoplankton occurred in the whole study area throughout 2003, and in the inner bay in February and August 2002. During the study period, factors controlling the distribution of nutrients might be summarized as follows; 1) inflow of freshwater by heavy rain accompanied by typhoons and frequent rainfall in summer, showing high concentrations of silicate and nitrate, 2) release of high phosphate concentrations from the fertilizer plant located in the south of Moydo to adjacent stations, 3) release of nutrients from bottom sediment, 4) magnitude of occurrence of phytoplankton standing crops.

• Ocean and Polar Research
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• v.33 no.2
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• pp.113-125
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• 2011

In order to assess the survival success of microphytoplankton species in ship ballast water, we examined microphytoplankton diversity from international commercial ships berthed at Ulsan and Pyeongtaek Ports, Korea, and also subjected them to laboratory studies. The ages of ballast water in each ship ranged from 1 to 365 days. Vessels originated from coastal China (Weihai, Lianyunsang and Shanghai), Chile, and from the Yellow and Pacific Oceans. The numbers of species and phytoplankton standing crops in uploaded ballast water were significantly related to the age of ballast water. The most diverse taxonomic group was diatoms. In the laboratory study, the value of in vivo fluorescence in M/V Spring Lyra gradually increased with increasing nutrients such as nitrate and phosphate. Phytoplankton in new (9 days), medium (31 days) and old (365 days) ballast water successfully survived under typical nutrient condition of port water and F/2 medium at $15^{\circ}C$ and $20^{\circ}C$, whereas phytoplankton in ballast water treatment did not survive, regardless of optimal temperature. Colonization process was dominated by diatoms; Skeletonema coastatum for M/V Spring Lyra, Thalassiosira pseudonana and Thalassiosira for M/V Han Yang, Thalassiosira pacifica and Odontella aurita for M/V Modern Express, and Chaetoceros pseudocurvisetus and Pseudo-nitzschia seriata for M/V Asian Legend. The successful establishment of non-native species was also related to nutrient richness. Our laboratory design can be applied as a practical tool to assess the survivability of invasive microphytoplankton introduced into local waters of Ulsan and Pyeongtaek.

• 한국해양학회지
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• v.4 no.2
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• pp.49-67
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• 1969

A quantitative phytoplankton study in Korean waters was commenced in 1964 as a part of the primary production studies of Koreans seas, and it was continued with the cruises for Cooperative Studies of the Kuroshio(C.S.K) in 1965-1968. Phytoplankton samples were taken by dipping about 500ml of sea water from the surface, and then fixed by ading neutralized formlin. This report deals with the results obtained during 1965-1966. I examined a total of 298 samples of surface phytoplankton collected in the wate neighboring Korea in the above-mentioned period, and detected 147 species of diatoms and 22 species of dinoflagellates. Among them 123 species of diatoms and 18 species of dinoflagellates occured in the Japan Sea region, 133 species of diatoms and 11 species of dinoflagellates occured in the Korea Strait region, and 49 species of diatom and 8 species of dinoflagellates occured in the Yellow Sea region. And thd phytoplankton standing crops are dept in a fair abundance in the Japan Sea area all the year round, and are poor in the Yellow Sea area. The seas surrounding Korea are divided into seven regions by the planktological characteristics; northern and southern parts of the Japan Sea, eastern, western and southern parts of the Korea Strait, southern and northern parts of the Yellow Sea. The representative of the phytoplankton community in each sea region is generalized as follows; northern part of the Japan Sea is dominant with Chaetoceros group, southern part of the Japan Sea is dominant with Chaetoceros group and Skeletonema costaum, eastern part of the Korea Strait is dominant with Chaetoceros group and Pleurosigma sp., southern part of the Korea Strait is dominant with Chaetoceros group and Rizosolenia group, western part of the Korea Strait is most poor in phytoplankton, southern part of the Yellow Sea is dominant with Pleurosigma sp. and Coscinodiscus group, and northern part of the Yellow Sea is dominant with Pleurosigma sp. and Eucampia zoodiacus. Chaetoceros curvisetus, Leptocylindrus danicus, Pleurosigma normanii, Thalassionema nitzschioides, Thalassiothrix flauenfeldii appeared all the year round in the neighboring sea of Korea. There were 24 species (18 species of diatoms and 6 species of dinoflagellates) of the pecuriar phytoplankton in the Japan Sea, 27 species (25 species of diatoms and 2 species of dinoflagellates) of that in the Korea, and 7 species (5 species of diatoms and 2 species of dinoflagellates) of that in the Yellow Sea, respectively.