• Proceedings of KOSOMES biannual meeting
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• 2018.06a
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• pp.203-203
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• 2018

• Journal of the Korea Academia-Industrial cooperation Society
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• v.21 no.11
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• pp.477-493
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• 2020

This study conducted a seasonal survey to analyze the spatio-temporal variations of marine environments and phytoplankton community in Gochang Coastal Waters (GCW) from August 2016 to April 2017. In the results, the water temperature ranged from 2.1℃ to 34.5℃, showing a large seasonal variation, but the salinity changed from 31.14 psu to 32.64 psu. Therefore, the seasonal variations of water types in GCW were mainly determined by water temperature. The phytoplankton community consisted of 53 genera and 86 species, showing a relatively simple distribution. The phytoplankton cell density ranged from 2.2 to 689.2 cells mL^-1, with an average of 577.2 cells mL^-1, which was low in autumn and high in winter. The seasonal succession of phytoplankton dominant species was mainly diatoms during the whole year, Leptocylindrus danicus, Chaetoceros curvisetus, Skeletonema costatum-ls in summer, Paralia sulcata, Eucampia zodiacus in autumn, S. costatum-ls, Thalassiosira nordenskioeldii in winter, and S. costatum-ls, Asterionella glacialis in spring. In other words, the phytoplankton community showed high diversity in GCW throughout the year. According to the PCA, GCW were easily heated and cooled by radiant energy at lower depth, and the seasonal distributions of phytoplankton were determined by the supply of nutrients by re-fuelling of surface sediments due to the seawater mixing such as tidal mixing.

• Korean Journal of Environmental Biology
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• v.31 no.3
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• pp.213-224
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• 2013

Between May 2006 and November 2009, we investigated the relationship between fluctuations in environmental factors and phytoplankton communities in Saemangeum Artificial Lake, South Korea. Nutrient concentrations in the lake increased because of the inflow of water from Mankyung and Dongjin Rivers during the summer rainy season; in particular, high concentrations were detected at an inner zone close to the estuaries. During the summer rainy season, salinity at the inner zone reduced more rapidly than that at the other zones, and it was similar to the changes in nutrient concentrations. Variations in phytoplankton communities were caused by fluctuations in environmental factors: the abundance of phytoplankton at the inner zone was higher than that at the other zones. Diatoms were the dominant species in the phytoplankton communities. A small centric diatom, Skeletonema costatum like species, was predominant, with a mean abundance of 19.5% in Saemangeum lake. Because of accelerated eutrophication in the lake, phytoplankton abundance increased continuously and the total number of species present in the community decreased. In particular, some dinoflagellates could intermittently cause red tides during low temperature and salinity conditions (at the inner zone). In 2006~2007, a red tide-forming dinoflagellate, Prorocentrum minimum, was the predominant species, while Heterocapsa triquetra, Karlodinium veneficum, and Heterocapsa rotundata were the newly recorded species in late 2008 to early 2009. Therefore, the dynamics of phytoplankton communities under the perennially eutrophic conditions in Saemangeum lake appear to be primarily affected by changes in water temperature and salinity. In particular, the growth of harmful algae may have been accelerated by the low salinity and temperature conditions during the spring season at the inner zone.

• ALGAE
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• v.23 no.3
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• pp.219-230
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• 2008

The structure of phytoplankton community was studied for one year round at 6 stations in the Beopsu Marsh, Haman-gun, Gyeongsangnam-do, Korea. One hundred seventy-eight taxa (69 taxa belonging to Chlorophyta, 55 taxa to Bacillariophyta, 33 taxa to Cyanophyta, 15 taxa to Euglenophyta, 2 taxa to Rhodophyta, 2 taxa to Dinophyta and 1 taxon to Xanthophyta) were observed. Phytoplankton bloom occurred at the staions 2, 3 and 4 where waters were polluted by sewage and treated water of purification plants from the vicinity. The species diversity index of phytoplankton was the lowest (0.66) in November at the station 3, which the station showed the most eutrophic water due to the diverse pollutants from surroundings of the marsh. For the whole seasons, Fragilaria sp. and Euglena sp. appeared in pollutant water at the station 3, while Cyclotella sp. and Pinnularia sp. inhabited in relatively clean water at the station 5. To reserve the natural treasure, the wetland should be more specially managed by a local governing institution.

• 한국해양학회지
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• v.17 no.1
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• pp.1-11
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• 1982

A study on the community and distribution of phytoplankton of the Kum River Estuary has been done in fall, 1980 and spring, 1981. Ond hundred and one taxa representing 22 families, 41 genera, 107 species, 2 varieties, and 2 forms were identified. The community of the study area composed mainly of diatom species icluding the very small fraction of dinoflagellates, blue-greens and greens. The dominant species were Skeletonema costatum, Paralia sulcata, and Asterionella kariana. The total standing crop of phytoplankton of winter samples was 115,000 cells/1 in average and that of spring samples was, 1,320,333 cells/1 in average. Of the representative members, dominant species above appeared moree than 10% of the total standing crop, Skeletonema costatum being maximized up to 46%. In spring Asterionella japonica, Thalassionema nitzschioides, and Chaetoceros curvistetus appeared 3∼8%, and Thalassiosira excentricus 3% in winter. The distribuion of marine forms showed negative correlation with that of fresh water forms, although the brackish-water forms showed no relationship. This change pattern of marine, brackish and fresh-water forms are discussed with the results of time series analysis. A list of phytoplankton species observed in this study is added.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.46 no.4
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• pp.467-487
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• 2013

Long-term and systematic monitoring of phytoplankton is important, as phytoplankton serve as indicators of water quality status in aquatic environments. In the present study, the plankton community structure of the Nakdong River estuary over the past 30 years was investigated by literature survey to provide references for the occurrence of planktonic species. A total of 876 species from 18 taxonomic lineages were reported and, among them, 569 species were identified to occur seasonally at the Mulgeum, Seonam and Eulsukdo sites. Diatoms and chlorophytes were dominant in the microscopic studies. The 54 species at the Mulgeum and the 96 species at the Eulsukdo sites have not been reported since the river barrage construction in 1987. The majority of reports speculate that there has been a change in the aquatic environment, particularly the plankton community structure, due to operation of a river barrage since 1987.

• Journal of the korean society of oceanography
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• v.32 no.1
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• pp.46-55
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• 1997

The quantitative determination of carotenoids, chlorophylls and their degradation products from marine phytoplankton was performed by reverse-phase high performance liquid chromatography (HPLC). Separated and quantified chlorophylls and their degraded products are chlorophyll a, b, c, chlorophyllide a, phaeophytin a, b and phaeophorbide a. Concentrations of six carotenoids including fucoxanthin, 19'-butanoyloxyfucoxanthin, 19'-hexanoyloxyfucoxan-thin, prasinoxanthin, alloxanthin, zoaxanthin/lutein were also determined from natural field samples by absorbance. Results of pigment analysis of field samples collected from the southern waters of the East Sea on October 8th, 1996 were reported. Concentration of chi a ranged from 7.2 to 180.4 ng/1. Concentration of chi b and chi c ranged from 22.7 to 53.7 ng/1 and from 3.3 to 58.5 ng/1, respectively. Significant concentrations of phaeophytin a, and chlorophyllide a were also detected at different depths. Fucoxanthin, 19'-hexanoyloxyfucoxanthin and zoaxanthin/lutein were the most abundant carotenoids and 19'-butanoyloxyfucoxanthin, prasinoxanthin and alloxanthin were also detected relatively at low concentrations. These results of pigment analyses suggest predominance of diatom, prymnesiophytes and cyanobacteria and presence of crysophyte, green algae (prasinophyte and prochlorophyte), and cryptophyte in the study area on October 8th, 1996, We report prymnesiophyte for the first time as an important biomass component of marine phytoplankton in the study area. Vertical profiles for the concentration changes of the major pigments were also given.

• Ocean Science Journal
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• v.41 no.3
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• pp.181-189
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• 2006

Frontal areas between warm and saline waters of the Kuroshio currents and colder and diluted waters of the East China Sea (ECS) influenced by the Changjiang River were identified from the satellite thermal imagery and hydrological data obtained from the Coastal Ocean Process Experiment (COPEX) cruise during the period between March $1^{st}$ and $10^{th}$, 1997. High chlorophyll concentrations appeared in the fronts of the East China Seas with the highest chlorophyll-a concentration in the southwestern area of Jeju Island (${\sim}2.9\;mg/m^3$) and the eastern area of the Changjiang River Mouth (${\sim}2.8\;mg/m^3$). Vertical structures of temperature, salinity and density were similar, showing the fronts between ECS and Kuroshio waters. The water column was well mixed in the shelf waters and was stratified around the fronts. It is inferred that the optimal condition for light utilization and nutrients induced both from the coastal and deep waters enhances the high phytoplankton productivity in the fronts of the ECS. In addition, the high chlorophyll-a in the fronts seems to have been associated with the water column stability as well.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.5
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• pp.381-390
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• 1987

To evaluate the effects of the cooling water system on the primary production of marine phytoplankton, a series of experiments were made at the cooling water system of Samchonpo Power Plant from May 1985 to May 1986. Mechanical and physiological perturbations of the entrained process are the most detrimental to the primary production of marine phytoplankton. Nevertheless the primary production is increased by the heated water within the upper limit of temperature tolerence of the phytoplankton. The cooling water system, on the average, reduces the gross production and net production by 4.6 to 12.1 and 8.4 to $11.9\;mgC/m^3/h$, respectively.

• Journal of Environmental Science International
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• v.15 no.10
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• pp.961-966
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• 2006

An algal assay procedure using an indigenous phytoplankton assemblage was tested to estimate the propagation of red tide phytoplankton species and determine the optimal time interval at which to measure growth yield in eutrophic marine waters where red tides frequently occur. Various red tide phytoplankton species were propagated on a large scale by adding nitrogen or phosphorous. This procedure was useful for estimating the limiting nutrient, elucidating the mechanisms underlying red tides, and determining the levels of increases in organic matter in eutrophic coastal waters. The algal assay using indigenous C. polykrikoides showed that this species did not always propagate, apparently because of very low concentrations of trigger elements that are necessary for its growth, rather than as a result of other environmental characteristics, e.g., water temperature or stress from sampling. In the winter, when water temperatures are lower than in spring, summer, or autumn, maximum propagation and the limiting nutrient could be estimated by measuring phytoplankton biomass at 2 - 3-day intervals. However, in the other seasons, when water temperatures are higher, phytoplankton biomass should be measured at 2-day intervals. In particular, daily monitoring will be required to determine precise growth yields in warm seasons.