• 한국해양학회지
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• v.15 no.2
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• pp.100-107
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• 1980

1974년 9월부터 1980년 1월까지 6년간 진해만에서 식물성플랑크톤 개체군의 생태적 천이에 관하여 조사하였다. 1974년 9월∼1975년 5월에는 천이계열이 Skeletonema costatum-Eucampia zodiacus Chaetoceros spp.-Nitzschia pungens- Leptocylindrus danicus, 1976년 7월-1978년 5월 Skeletonema costatum-Thalassiosira hyalina- Chaetoceros spp. -Leptocylindrus danicus(Nitzschia pungens), 1978년 7월-1980년 1월 Chaetoceros socialis-Skeletonema costatum-Chaetoceros spp. -Leptocylindrus danicus-Skeletonema costatum(Biddulphia mobiliensis)으로 천이계열이 바뀌어가고 있으며 이들은 계절에 따라 수온의 변화와 밀접한 관계가 있었다. 최근에는 이 해역에서 Skeletonema costatum이 계절에 관계없이 대량출현하여 이 종에 의해 점점 성숙한 천이계열을 형성해 가고 있다.

• Korean Journal of Environmental Biology
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• v.17 no.4
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• pp.481-492
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• 1999

The observations on the spatio-temporal distribution and seasonal fluctuations of phytoplankton community were carried out in Deukryang Bay of the Korean Southwestern Sea from June 1992 to April 1993. A total of 75 species of phytoplankton belonged to 47 genera was identified. In Deukryang Bay seasonal succession in dominant species; P. alata, G. flaccida, S. costatum, L. danicus and N. longissima in summer, St. palmeriana, Ch. curvisetus and B. paxillifera in autunm, S. costatum, Ch. curvisetus, E. zodiacus and Pn. pungens in winter, and As. glacialis, As. kariana, N. pelagica, Th. nitzschioides and S. costatum in spring, were very marked, that is to say, the communities structure of phytoplankton in Deukryang Bay appeared to be various species composition and it was occupied with diatoms all the year round. Phytoplankton standing crops fluctuated with an annual mean of $1.4{\times}10^5 cells/1 between the lowest value of 2.6{\times}10^3 cells/1 in July and the highest value of 1.0{\times}10^6 cells/1$ by S. costatum in January. Densities of the phytoplankton cell number by the samples of Deukryang Bay ranged from $2.6{\times}10^3cells/1 to 1.2{\times}10^5 cells/1 with the mean value of 3.6{\times}10^4cells/1 in summer, from 6.0{\times}10^3cells/1 to 2.6{\times}10^5 cells/1 with mean of 1.5{\times}10^5 cells/1 in autumn, from 1.3{\times}10^4cells/1 to 1.0{\times}10^6 cells/1 with mean 3.5{times}10^5 cells/1 in winter, and from 4.8{\times}10^3cells/1 to 6.0{\times}10^5 cells/1 with mean of 1.6{\times}10^5 cells/1$ in autumn. That is to say, phytoplankton standing crops was large in low temperature seasons, on the other hand small in high temperature seasons. Chlorophyll $\alpha$ concentration fluctuated between 0.l9 $\mu$g/l and 12.3 $\mu$g/l in March. in Deukryang Bay seasonal flucturation in chi-$\alpha$ concentration was not marked. Especially, chl-$\alpha$ concentration in the water around Deukryang Island located in the middle part of Deukryang Bay showed patchy distributions with a very high concentration. And chl-$\alpha$ concentration was high during a year. Therefore, phytoplankton production in Deukryang Bay could be very high year-round.

• Korean Journal of Ecology and Environment
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• v.37 no.1 s.106
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• pp.47-56
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• 2004

To understand the effect of nutrient deficiency on the plankton community in three stations with different water qualities in Pal'tang Reservoir, Korea, phytoplanktons(> 10 ${\mu}m$) were cultured in nutrient enrichment Allen's media (AM) and nutrient-deficient Allen's media. A distinct shift in the species composition and biomass of phytoplankton (as chlorophyll- a) showed in all treatments. In particular, it was very interesting that the new development of cyanobacterium Microcystis aeruginosa occurred by the Fe-deficient AM. Except for Si, a community growth (as chlorophyll- a) was inhibited in all nutrient deficient treatments. Species diversity after nutrient deficiency was changed to below 2.0; slightly increased in N and P-deficiency, while decreased in Si and Fe, respectively. As suggested, dominance was entirely opposite to diversity. Therefore, the nutrient deficient effectively induced the succession of species and biomass, phytoplankton community, suggesting a possibility as a reliable tool to control the algal bloom in eutrophic lakes and reservoirs.

• Journal of Korean Society on Water Environment
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• v.34 no.4
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• pp.423-430
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• 2018

Insomuch as it is important to manage water quality, from the perspective of water management, it is essential to understand the effect of the weirs on water quality and phytoplankton dynamics in various regions. The purpose of this study is to investigate the characteristics of nitro-nutrients, as well as occurrences and succession patterns of phytoplankton, in the river sections of the two weirs in the Yeongsan River for the five years (from 2012 to 2016) after the weir construction. In respect to this data, the average water temperature measured at the representative point in the section of the Seungchon Weir ($17.1^{\circ}C$) was higher than that of the Juksan Weir ($16.6^{\circ}C$) by comparison. By way of an analysis of this data, it was found that the water quality variables such as, organic matter, nitrogen nutrients and phosphorus nutrients were improved gradually during the period, but the degree of the improvement differs as noted and measured between the weirs. Under the circumstances, it is especially noted that the $NH_3-N$ concentration was higher for the point of the Seungchon Weir (2.204 mg/L) than that of the Juksan Weir (1.157 mg/L). This indicates that effluent as seen from sewage treatment plants and hydrological feature near the densely population area, could be the main cause for the incidence of water pollution in the upstream section of the Seungchon Weir. Additionally, the phytoplankton analysis showed that a relative abundance of diatoms and green algae were 56.9 % and 25.8 % respectively. However, it is noted that the cyanobacteria was measured lower as 10.7 %. Also, in the study sites cell density and occurrence frequency of cyanobacteria were relatively lower than compared to the same measurements noted in other rivers.

• Journal of Korean Society on Water Environment
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• v.34 no.5
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• pp.503-513
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• 2018

Freshwater cyanobacterial genus Dolichospermum is one of the most commonly spotted types of phytoplankton, whereas a limited number of studies on morphology of Dolichospermum spp. have been performed in South Korea. The purpose of this study is to investigate the succession pattern of cyanobacteria after weir construction, as well as morphological characteristics of Dolichospermum spp. from natural samples collected in the weir regions of Nakdong River. A total of 31 cyanobacterial taxa observed in this study were classified as belonging to 15 genera, 5 families, and 3 orders. Among them, morphological characteristics in the four species were classified into genus Dolichospermum, for most of the planktic former members of the genus Anabaena, were observed through light microscopy. Water bloom frequently occurred in the middle region of Nakdong River, the maximum number of cyanobacterial species appeared in the lower region of Nakdong River. The appearance of order Chrooccocales was only observed during summer when population density of Microcystis aeruginosa reached an annual peak. In contrast, filamentous cyanobacteria was observed throughout the whole year, even if when water temperature was lower than $5^{\circ}C$. It implied that the low-temperature-adapted filamentous cyanobacteria can grow in a range of water temperatures. Coil diameter of D. crassum from natural samples was $75{\sim}140{\mu}m$ ($ave.=91.3{\mu}m$; n = 94), slightly larger than those reported by previous studies. Dolichospemum smithii ($Kom{\grave{a}}rek$) Wacklin et al. 2009, was described for the first time in Nakdong River.

• Korean Journal of Ecology and Environment
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• v.38 no.2 s.112
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• pp.181-187
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• 2005

For 4 years (2000 ${\sim}$ 2003), annual fluctuations of standing crops of cyanobacteria and physicochemical factors were examined at five sites from Bridge of Seungsoo to Bridge of Seungsan in the lower part of Han River. The cyanobacterial abundance (ND to 4,167 cells $mL^{-1}$) was strongly decreased during the heavy rains in every year. During the similar periods in 2003, cyanobacteria hardly observed, and comprised below of 10 percentage of total phytoplankton. In the period of little cyanobacteria, some green algae and diatom dominated the phytoplankton community, while the concentration of chlorophyll a has not largely change. These results indicate that heavy frequent precipitation strongly limited the growth of cyanobacteria, and lead an algal succession by the appearance of new algal groups.

• Journal of the Korean Society for Marine Environment & Energy
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• v.11 no.2
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• pp.98-104
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• 2008

In April, July, October and December, 2003, we investigated the effects of water temperature, salinity and extinction coefficient on the distribution of phytoplankton communities at 22 stations in Jinju Bay of Korea. Water temperature and salinity showed a wide range of $10.4^{\circ}C-21.8^{\circ}C$ and 4.34-33.21 psu. Extinction coefficients showed a range of 0.09-3.08, above 1 from almost all the areas except in some central areas, especially, showed highest value (>2) in the estuary area. In phytoplankton, a total of 95 species belonging to 51 genera were identified. The predominant species were mainly diatoms throughout the year. Dominant species was Thalassionema nitzschioides, Skeletonema costatum, Thalassiosira sp. in April, S. costatum, Leptocylindrus danicus in July, C. debilis, S. costatum, C. curvisetus, Pseudonitzshia pungens in October, S. costatum, Asterionellopsis glacialis and C. debilis in December. S. costatum was a major dominant species for all the seasons. Considering the results of literature which is about physiological study, S. costatum seems to be euryhaline and eurythermal, and high affinity on the irradiance. Thus, the species might have been spread population in Jinju Bay where is characteristic of wide range of water temperature, salinity and high extinction coefficients.

• ALGAE
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• v.22 no.4
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• pp.261-271
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• 2007

The variations of species compositions, standing crops and seasonal succession of phytoplanktons including Cyanophyceae, Chlorophyceae and Bacillariophyceae were investigated with physico-chemical elements of water to clarify the causes of water bloom according to the water depth in the Lake Unmun. The increased amounts of turbidity, T-N, T-P and SS originated from heavy rain and typhoon in the middle of June provoked to produce phytoplanktons. In July and August, the dominant species was Peridinium sp., while the subdominant species was Microcystis aeruginosa. In October, Aulacoseira distans was dominant and Asterionella formosa was subdominant. During the period of water shortage, the concentrated pollutants caused the decrease of precipitation, the long stagnation time of water body and the mixed pollutants by upwelling as decreasing water temperature could accelerate the water bloom. The preventives to decrease microalgal generation should be controled by the stagnation time of water body by increasing outflow to intercept water bloom such as ulacoseira sp. in October as well as summer.

• ALGAE
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• v.17 no.3
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• pp.171-185
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• 2002

The standing crop of genus Microcystis, microcystin concentrations and environmental factors were monitored at stations of the lower reaches of the Nakdong River in 1998 and 1999 during the periods of its occurrence. The Microcystis were observed from May to Octorber, and the cell density was highest at Station Seonam up to 250,000 cells${\cdot}ml^{-1}$ forming scum over the water surface. There were signigicant relationships between the standing crop of Microcystis and nitrate nitrogen, total phosphorus concentrations and Ph. Presumably these parameters were important in the succession to Microcystis dominated phytoplankton community in the summer period in the river. However, Ammonium nitrogen, phosphate phosphorus concentrations and N/P ratio were not critical factors. The Microcystis bloom was notable above $25^{\circ}C$ of surface water temperature. Microcystins were detected from May to November in the algal materials from the river. The 84.2% of algal materials with Microcystis exhibited the microcystin with the maximum of 1711.8 ${\mu}g{\cdot}g^{-1}$ dw. The microcystin concentrations in the algal materials were significantly related to the stading crop of Microcystis, which was the primary determinant factor in the toxin levle of algal materials. The concentrations were also significantly related to pH of the water column in the positive pattern.

• Korean Journal of Environmental Biology
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• v.28 no.1
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• pp.20-29
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• 2010

Cochlodinium polykrikoides has occurs regularly during the summer in the South Sea of Korea. To investigate photosynthetic pigments concerned with phytoplankton community structure as bloom of Cochlodinium polykrikoides, the experiment was sampled at 20 stations three times between July and September 2002 in the Southern Sea of Korea. The distribution of peridinin, the biomarker of dinoflagellate, was higher at the blooming time than it was before and it disappeared after bloom. The correlative coefficients between Chl. a and peridinin at the blooming time and out of bloom were 0.9253 and 0.1613, respectively. This result indicated that the bloom was caused by dinoflagellate. The correlative coefficients between Chl. a and fucoxanthin were 0.3282 and 0.9759, respectively, and the correlative coefficients showed the succession from dinoflagellate to diatom. This result means that the bloom of Cochlodinium polykrikoides can be detected by Chl. a information from satellite remote sensing. Therefore, if the algorithm to detect peridinin in addition to Chl. a were to be developed, dinoflagellate red tide could be monitored more effectively.