• ALGAE
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• v.20 no.4
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• pp.333-343
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• 2005

Spatial and temporal variations of environmental factors and phytoplankton community were investigated in the three stations of Andong Reservoir in 1997 and 2003. The changes of physico-chemical water quality and phytoplanktonic biomass were higher in 2003 than that of 1997, due to rainfall difference. The concentration of total nitrogen (TN) and total phosphorus (TP) in the reservoir decreased, but total nitrogen fell relatively more between them. TN/TP ratio decreased from 109 to 90 showing no change at the downstream but a big decrease at the midand upstream. Predominant phylum of phytoplankton in Andong Reservoir were six genus that composed to Anabaena, Aphanizomenon and Microcystis of Cyanophyceae, Cosmarium and Scenedesmus of Chlorophyceae and Synedra of Bacillariophyceae, respectively. Among the observed phytoplankton, diatom Synedra occured as the maximum amount of 3,400 cells mL$^{-1}$ even at the above 30°C. Green algae Scenedesmus observed along with Microcystis. It seemed to be compete with Microcystis during the high water temperature period. Although trophic state of Andong Reservoir was decreased, the standing crops of phytoplankton were increased. Moreover bluegreen algae, Aphanizomenon and Microcystis in the region of upstream to midstream and diatom, Synedra in the region of midstream to downstream were increased until to reach the algal bloom, respectively. It seemed necessary to attention the changes of blue-green algae Aphanizomenon, that has an ability of nitrogen fixation.

• 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.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.16 no.4
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• pp.379-388
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• 1983

The subtidal benthic algal communities of Dolsan-island in the southern coast of Korea were surveyed by means of SCUBA diving. The vertical zonation is recognized into three groups; upper, middle and lower subtidal zones. The representative species in each group throughout the year are Ulva pertusa, Codium fragile, Chondria crassicaulis and Gigartina tenera in the upper, Myagropsis myagroides and Sargassum tortile in the middle, and Plocamium telfairiae, Callophyllis japonica and Symphyocladia linearis in the lower zone. According to the normal association analysis by $2{\times}2$ contingency table and chi-square calculation among 29 quadrats, the algal communities are divided into 9 groups which are dominated by Sargassum tortile, Myagropsis myagroides, Chondria crassicaulis, Codium fragile, Pterocladia tenuis, Gigartina tenera, Gracilaria textorii. The thallus length and standing crops of Myagropsis myagroides show the highest value in spring and the lowest in summer.

• Journal of environmental and Sanitary engineering
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• v.14 no.4
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• pp.50-68
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• 1999

The present study was performed to examine on the fauna and standing crops of benthic macroinvertebrates in Pongwha and Youngwol region of upper parts of south han river and Naktons river. The Actual site suvry was caried out on the two times during the April·June to October·November, 1988. Main five areas are Mt. Awrawe(1,067m), Mt. Sontal (1,236m), Mt. Munsu(1,206m), Peak Okyopong(357m) and Mt. Pungnak(760m) area. Total taxa of benthic macroinvertebrates of the study area were 118 species, 45families12 orders, 5 classes in 4 phyla. Occurrence species according to the major taxa of aquatic insects were 35 species (29.66%) in ephemeroptera, 25 species(21.19%) in trichoptera, 25 species(21.19%) hemiptera, 1 species(0.85%) in megaloptera. Non-aqautic insect were 5 species in mollusca, 3 ratio was 8.5 percent. Occurrence species(plecoptera) at clean waters were appeared 12 species at Mt. Awrawe and Sontal area. Occurrence species at each survey area was 67 species at Mt. Awrawe area, 60 species at Mt. Sontal area, 43 species at Mt. Munsu area, 37 species at Mt. P'ungnak area and 34 species at Peak Okyo area, respectively. Species diversity indices were 2.96~3.80 at Mt. Awrawe area, 2.79~3.62 at Mt. sontal area, but 2.64~3.12, 1.59~2.46 and 1.98~2.59 at, Mt. Munsu, P'ungnak and Peak Okyo area, respectively. In this region, occurrence species and individual density were smaller than that of Dong river with good habitat, but those were more abundant than that of Poseong river with similar environment conditions. Therefore, occurrence species and individual density of the present survey region were appeared as somewhat abundant.

• 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.

• Journal of Environmental Science International
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• v.9 no.2
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• pp.115-123
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• 2000

The dynamics of water quality and phytoplankton population had examined by monthly sampling from the upper to the lower part of watergate in an artificial Shihwa Reservoir in which situated near newly cities and incustrial complex on the west coast of Korea from January 1997 to December 1998. Among environmental factors, yearly average concentration of chl-a, TN and TP seemed to eutrophic or hypertrophic conditions that ranged 146.4~245.8 $\mu\textrm{g}$/$\ell$, 1.6~2.7 mg N/$\ell$, 258~448 $\mu\textrm{g}$ P/$\ell$, 26.9~80.7 $\mu\textrm{g}$/$\ell$, 1.0~2.4 mgN/$\ell$ and 74~239 $\mu\textrm{g}$P/$\ell$ respectively. Water quality was extremely deteriorated to consistently accumulation into inner reservoir by load of pollutants from autochthonous and allochthonous until early July 1997 after embankment. Water pollution of Shihwa Reservoir was remarkble on the biological condition with largely persistent bloom of phytoplankton and increase rate of standing crops was 2.4/yr. The development trend of phytoplankton in water ecosystem were closely related to increse and decrease of physico-chemical factors and those scale seemed to control by nutrient contents. Inflow of seawater into reservoir to object of repair of water quality. As to see dominant species, composition of those composed to mostly freshwater algae before inflow of seawater such as Selenastrum capricornutum of green algae, cyclotella atomus, C. meneghiniana of diatom and Microcystis spp. of blue-green algae and the other hand brackish algae were dominated after inflow of seawater such as Chaetoceros dicipiens, Skeletonema costatum of diatom, Dinophysis acuminata, Gymnodinium mikimotoi, G. sanguineum, Gyrodinium spirale, Prorocentrum minmum of dinoflagellate and Eutreptiella gymnastica of euglenoid. Moreover, small flagellates including Chroomonas spp. of cryptomonad were abundant throughout the year. The cause of water deterioration during fill of the freshwater were complexly supported with extra and intra parameters. The variation pattern of phytoplankton were related to water temperature and salinity by inflow of seawater based to plentiful nutrients. The dynamics of phytoplankton were assessed to ecosystem that clearly condition of dominant by unique or a few angel species seasonally.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.20 no.3
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• pp.230-236
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• 1987

The correlation between tintinnid and dinoflagellate by means of seasonal variation of standing crops was investigated at two selected stations in Masan Bay, well-known as a red tide zone in southern coastal waters of Korea, during the period from January 1981 to December 1982. The most dominant dinoflagellates mainly belonged to $20-60\;{\mu}m$ of size class, and Gymnodinium and Prorocentrum were predominant from spring to summer season. Of tintinnid, Favella spp. were most dominant and associated with dinoflagellate blooms at the same season. Especially, Favella spp. were most positively correlated with $40-60\;{\mu}m$ size class of dinoflagellate, and also represented higher multiple corrleation with outer station (St.2), comprising relatively large species of Gymonodinium and Protogonyaulax, than with inner station (St. 1), dominated by Prorocentrum blooms. Thus, the interspecific food selection by size and morphology between tintinnid including Favella and dinoflagellate is recognized and it is considered to be an important factor influenecing on the prey-predator relationship in lower trophic level in the surveyed area.

• 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.

• Journal of Plant Biology
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• v.19 no.3
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• pp.85-91
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• 1976

A comparison betwen the productivity of Pinus rigida which is native in the Eastern United States, and P. rigitaeda which is F1 hybrid between P. rigida and P. taeda, has been established. For each tree the diameter at breast height (D) and the height of tree (H) were measured in three years. The standard sample trees were down and then weighed each organ. From obtained data the allometric relation between $D_2H$ and dry weight of the trunk (Ws), the branches (Wb) and the leaves (Wl) of P. rigida were approxmated by $$Ws=0.0592 (D^2H)^{0.837}$$ $$Wb=0.0065 (D^2H)^{0.989}$$ $$Wl=0.0447(D^2H)^{0.690}$$ and those of P. rigitaeda were approximated by $$Ws=0.0522 (D^2H)^{0.843}$$ $$Wb=0.0037 (D^2H)^{1.117}$$ $$Wl=0.0207 (D^2H)^{0.856}$$ From the above, the standing crops of above ground of P. rigida were estimated to be as much as 16.93-34.35 ton dry matter per ha, and those of P. rigitaeda were 20.45-45.55 ton per ha. Annual net production was appraised at 8.07-9.35 ton/ha.yr in P. rigida and at 11.59-13.41 ton/ha.yr in P. rigitaeda (1.0:1.4). It is assumed that high productivity of P. rigitaeda stand compared with P. rigida resulted from an increase of the leaf amount with age. Photosynthetic ability under the saturated light of the current and theold leaves of P. rigida were respectively 2.62 and 0.66mg CO2/g. d. wt..hr and those of P. rigitaeda were 1.17 and 0.96mg CO2/g.d. wt.hr. Respiration of the current and the old leaves at $25^{\circ}C$ were 1.00 and 0.90 mg CO2/g. d. wt..hr. in P. rigida and 0.90 and 0.45mg CO2/g.d.wt.hr in P. rigitaeda. It is assumed that photosynthetic longevity of P. rigitaeda leaves was vigorously maintained longer than that of P. rigida.

• Korean Journal of Environmental Biology
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• v.21 no.2
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• pp.132-141
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• 2003

We carried out a study on thermohaline structure and phytoplankton com munity in the East China Sea during early summer in 2005. As a result of marine environment and phytoplankton community, three characteristics of water type were identified. The former was characterized by the dominant species with diatoms, Chaetoceros lacinious, Ch. decipiens, Guninardia flaccida, Paralia sulcata, Pseudonitzschia pungens and Pseudosolenia calcar-avis in Chinese coastal waters, the secondary was done by lower water temperature, salinity and the dominant species with dinoflagellates, Prorocentrum donghaiense and Ceratium fusus, in over-all areas and the latter was done by the dominant species with coastal species of diatoms, Skeletonema costafum and Nitzschia longissima and silicoflagellate, Dictyocha speculum var. octopers in the transfer areas of Chinese continental coastal waters. Phytoplankton community in the surface layer identified a total of 66 species belonging to 36 genera. Dominant species was Prorocentrum donghaiense, Chaetoceros lacinious, Skeletonema costatum. Standing crops of phytoplankton in the surface layer flue tuated between $1.5 \times 10^4$cells $L^{-1}$ and $3.5\times 10^{5}$ cells $L^{-1}$. And the highest value appeared in the Changjiang estuaries with high dominance by diatoms and lowest one occurred in the southwestern area of Jeju Island with high dominance by dinoflagellates. Red tides with dinoflagellate, Prororcentrum donghaiense appeared in the frontal areas with mazimum cell density, $3.4\times 10^5$ cells $L^{-1}$. And outbreak environments was low water temperature under $20^{\circ}C$, and low salinity under 31.55 psu. The vertical distribution of red tide organisms went to about 30m depth from surface.