• Ocean and Polar Research
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• v.25 no.4
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• pp.519-528
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• 2003

Species composition and community structure of marine benthic community were studied in the intertidal zone of Jijindo Island, Gwangyang Bay. A total of 85 species of benthic marine plants including the 5 Cyanophyta, 9 Chlorophyta, 13 Phaeophyta, 56 Rhodophyta and 2 Magnoliophyta that were listed. The community structure was represented by Gelidium divaricatum in the upper zone, Celidium divalicatum and Ulva pertusa in the middle, and Ulva pertusa, Chondria crassicaulis, Chondracanthus intermedia and Sargassum thunbergii in the lower intertidal zone. The dominant species in the rnscro-zoobenthic community were Chthamalux challengeri in the upper and middle, Littorina brevicula between the upper and middle, and Mytilus edulis and Crassostrea gigas in the middle and lower intertidal zones. The economic benthic organisms such as Undaria pinnatifida, Mytilus edulis, and Crassostrea gigas found in the lower intertidal zone were frequently disturbed due to their collection by local resident. Therefore, it is necessary to record the correct information pertaining to these cases. The species diversity indices estimated kom different sources were quite different. They were 2.22 derived from frequency, 1.67 based on coverage, 2.17 based on sum of frequency and coverage and 2.04 derived from importance value. Species diversity and number of algal species in Gwangyang Bay have noticeably decreased, compared with their previously reported status. It is estimated that their decreases were caused by changes in the marine environment, especially pertaining to the polychaete community resulting from reclamation and dredging activity undertaken for the industrial development.

• ALGAE
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• v.24 no.1
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• pp.39-45
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• 2009

The conjugation processes of a filamentous freshwater green alga Spirogyra varians were examined using FITC-lectins. Conjugation comprised five steps: 1) aligning with adjacent filaments, 2) formation of conjugation protru-sion (papilla), 3) fusion of the protrusions, 4) formation of conjugation tube,and 5) formation of zygotes. Three lectins, ConA, RCA and UEA, showed considerable labeling during the progression of conjuation. FITC-ConA labeled the surfaces of filaments throughout the whole conjugation processes. FITC-RCA labeling was observed at the conjugation protrusions only after the papilla formation. Strong labeling continued until formationg of zygotes at the contacting area where the conjugation tube developed, but no labeling was detected on the surface of vegetative filaments. The labeling decreased gradually over time and disappeared when zygotes were formed. FITC-UEA showed similar labeling pattern with FITC-RCA except that weak labeling remained after zygote formation. Inhibition experiments using RCA, UEA which are complementary to sugars L-fucose and D-galactose, showed considerable decrease of conjugation (<32% vs. 70% in control). These results suggested that the lectin-carbohydrate recognition system might be involved in the conjugation of spirogyra varians.

• ALGAE
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• v.25 no.1
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• pp.17-26
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• 2010

The effects of salinity on various ecophysiological parameters of Ulva pertusa such as growth, nutrient uptake, photosynthetic performance and internal nutrient composition were tested. U. pertusa was collected from an eelgrass bed in a semi-protected embayment on the southwest coast of Korea. Under salinity regimes from 5 to 40 psu, the specific growth rates $(\mu)$ of U. pertusa ranged from 0.019 to $0.032\;d^{-1}$. Maximum growth rate was observed at 20 psu, and minimum at 40 psu. This species showed various uptake rates for nitrate and phosphate. Nutrient uptake was noticeably higher at intermediate salinity levels, and lower at both extremes. Salinity significantly influenced chlorophyll-$\alpha$ content and effective quantum yield. Tissue nitrogen content ranged from 1.5 to 2.9% N (dry weight), whereas tissue phosphorus ranged from 0.1 to 0.14% P (dry weight). The N : P ratio in the tissue of U. pertusa was considerably higher, ranging from 30 to 50. Increased growth at lower salinity suggests that the initial growth rate of U. pertusa is greater during the rainy season (i.e., late spring and early summer) than any other season during the year. The appearance of an Ulva bloom in eelgrass beds may be triggered by salinity more than by other environmental factors such as light and temperature.

• Korean Journal of Environmental Biology
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• v.19 no.1
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• pp.37-42
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• 2001

The biomass of Ulva mats was surveyed in a lower rocky shore of the southern coast of Korea during the 1998-1999 winter. The population selected for the present study was located on the tidal zone ranging from 118 cm to 130 cm below mean sea level (MSL), where abundance of Ulvu species was highest. The biomass of Ulva species increased gradually from December 1998 until February 1999, reaching the maximum of 374 g dry wtㆍm$^{-2}$ in February. The biomass varied little among the sampling quadrats for each sampling time. Over the course of the study a total of 16 taxa were sampled from Ulva mats, of which 5 were macrophytes and 11 were macroinvertebrates. Rodophyta comprised 3 taxa, followed by Phaeophyta of 2 taxa, but there was no Chlorophyta except for Ulva species. The macrofaunal assemblage was consisted of 8 taxa of Mollusca, 2 Arthropoda and 1 Annelida. There was a dramatic increase in Mytilus sp. in February. Moreover, the trend of biomass were similar between some macroinvertebrates and Ulva species. The results suggested that macroinvertebrates may play an important role in nutrient dynamics as well as food web. Further experimental evidence may be necessary to explain the correlation between Ulva mats and abundance of coexisting macroinvertebrates.

• Korean Journal of Environmental Biology
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• v.36 no.2
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• pp.150-155
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• 2018

Two siphonous green algae were collected from the eastern coast of Korea. These species share the typical features of Derbesia sporophytes, such as erect and prostrate siphonous filaments and the presence of basal septum in lateral branches. One is characterized by the combined features of a relatively small tufted sporophytic thalli arising from a rhizoidal base, subdichotomously branched filaments with a basal septum and one pyrenoid per subspherical to lenticular chloroplast. The other shows a larger sporophytic thallus, sparsely subdichotomously branched filaments with a basal septum and one pyrenoid per spherical chloroplast. In a phylogenetic tree based on rbcL sequence, the two above-mentioned Korean algae nest in the same clades as Derbesia minima and D. indica, respectively. The genetic distance between the sequences within the clades was 0.5-0.8%, which is considered to be included in the intra-specific range for the genus. These two siphonous Korean algae are identified as D. minima and D. indica, respectively, based on the morphological and molecular analyses. These species are newly recorded in the Korean marine algal flora herein.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.43 no.3
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• pp.246-253
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• 2010

The marine algal flora and community structure were investigated at three sites in Ulsan on the southeast coast of Korea between August 2005 and July 2006. Ninety-one benthic algae species were identified, including 14 Chlorophyta, 21 Phaeophyta, and 56 Rhodophyta species. Of the 91 seaweeds, 19 species were found throughout the survey period. The wet weight biomass ranged from 310.8 to 2,960.4 g $m^{-2}$ during the study period. The maximum biomass was recorded at Sinri, and the minimum was recorded at Daesong. The R/P, C/P and (R+C)/P values reflecting flora characteristics were 2.67, 0.67, and 3.33, respectively. The flora investigated could be classified into six functional groups: coarsely branched (46.2%), thick leathery (22.0%), filamentous (16.5%), Sheet (7.7%), jointed calcareous (4.4%), and crustose (3.3%) forms. A cluster analysis produced two groups that differed meaningfully: one included the site Sinri-summer and the other included the sites Daesong and Jinha.

• Journal of Plant Biology
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• v.36 no.3
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• pp.219-224
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• 1993

The effects of environmental factors on the growth of Enteromorpha compressa germlings from Daeyulri (34$^{\circ}$36'N; 127$^{\circ}$47'E), the southern cost of Korea were examined in laboratory culture through combinations of irradiance and salinity and temperature and salinity. They showed a maximum growth rate at 125 $\mu$E.m-2.s-1 and 32$\textperthousand$ of irradiance and salinity combination, and at 15$^{\circ}C$ and 32% of temperature and salinity combination. Optimal parameters for the growth of germlings were 15$^{\circ}C$, 125 $\mu$E.m-2s-1 and 32$\textperthousand$. The germlings of E. compressa were survived in a wide range of irradiance, temperature and salinity levels, even though they had relatively low irradiance optimum. In the field E. compressa occurred commonly during autumn and spring seasons and disappeared in summer, except for particular habitats. This may be caused by the salinity and water temperature of this area rarely drop below 26$\textperthousand$ and 8$^{\circ}C$ during winter. A broad tolerance to environmental and rapid growth of germlings made them a wide geographical distribution over the world and a survival in both the upper and lower intertidal zones.

• Journal of the Korean Society of Food Science and Nutrition
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• v.34 no.8
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• pp.1293-1296
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• 2005

Nitrite plays an important role in the formation of carcinogenic nitrosamine. In order to effectively inhibit the formation of carcinogenic nitrosamine in food and biological systems, scavenging of residual nitrite is necessary. In screening test of nitrite-scavenging effect of seaweed, The methanol extract from Phaeophyta was more effective than those from Rhodophyta and Chlorophyta. Among the brown algae family, Laminariaceae, A. cribrosum (90.4$\%$) and E. cava (80.1$\%$), E. stolonifera (79.0$\%$) that belong to genus Ecklonia showed marked nitrite-scavenging effect at pH 1.2. Furthermore, these algae showed potent reducing power and radical scavenging activity. The nitrite-scavenging effect was correlated with level of reducing power.

• Journal of The Korean Association For Science Education
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• v.7 no.2
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• pp.21-35
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• 1987

Polyurethane foam was utilized to collect protists from the 2 ponds in Seoul National University and another pond in vicinity of Paldang Dam. The identified protists were 4 species in Cyanophyta, 2 species in Euglenophyta, 19 species in Chrysophyta, 9 species in Chlorophyta, 2 species in Ciliophora, and 3 species in Sarcodian. To test the adoptability of the sampling method for classes in junior and senior high school, frequency of the 25 protists in each observation and in each preparation were calculated. The families which were present at high frequencies were Naviculaceae. Fragilariaceae, Cymbellaceae and Coelastraceae. In an experimental application of the 40 pictures taken from the samples, students in junior classes recognized the protists by their outer morphology, internal structure. color, and colonial types, in decreasing order. Use of the collecting method and the applicability of protists for teaching biology were discussed.

• Journal of Environmental Science International
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• v.11 no.3
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• pp.149-154
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• 2002

This study was conducted to find the structure of phytoplankton community in the Hoeya river(Ulsan) from March 2000 to February 2001. The taxa of phytoplankton identified included 135 species, 5 divisions, 33 families and 82 genera. Among them, chrysophyta(diatoms) were 63 species(46.7%), chlorophyta(green algae) 47 species(34.8%), pyrrophyta(dinoflagellates) 13 species(9.6%), cyanophyta (cyanobacteria) 8 species(5.9%) and euglenophyta(euglenoids) 4 species(3.0%) respectively. Ecological important species is called frequently appearing species, red tide causative species, seawater species and pollution indicator. 22 species including Aulacoseira granulate were recorded frequently appearing species. 19 species including Ceratium furca were recorded as red tide causing species. And the pollution indicators were 33 species including Actinastrum hantzschii var. fluviatile. The highest standing crops were 3,103,441 cells/$\ell$ in August at the RW-1 and the lowest 1,245 cells/ $\ell$ in January at the RW-5. In the community analysis, the dominanance indices ranged from 0.34(October, RW-2) to 0.94(January, RW-1) and the diversity indices from 0.50(May, RW-2) to 2.57(September, RW-2). The saprobic indices were 2.43 in RW-1, 2.41 in RW-2, 2.375 in RW-3, 2.40 in RW-4, 2.43, in RW-5. Therefore, these areas were investigated "$\beta$-mesosaprobic". According to the similarity index among the stations, these areas were defined as residential district areas(RW-2 and RW-3), lower part of the dam (RW-1) and seawater areas(RW-4 and RW-5).