• ALGAE
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• 제24권1호
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• pp.47-55
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• 2009

Recently, interest in plant-derived food additives has developed natural antioxidants, in order to alternate syn-thetic antioxidants with several disadvantages. In the present study, different organic fractions from solvent parti-tions of 80% methanol extract from Jeju benthic diatoms, Achnanthes longipes, Navicula sp. and Amphora coffeaeformis was assessed for their potential antioxidant effects. Among the solvent fractions tested, n-hexane (80.4%) and 80% methanol extract (76.6%) from A. longipes, chloroform (63.2%) from Navicula sp. and n-hexane (67.4%) from A. cof-feaeformis were effective in DPPH free radical scavenging. Fractions of chloroform (53.4%) and n-hexane (53.1%) from A. longipes exhibited higher activities on $H_2O_2$ scavengin. Fraction of n-Hexane from A. longipes exhibited the highest hydroxyl radical scavenging activity and NO. scavenging activity (56.5% and 75.6%, respectively). Aqueous residue from A. coffeaeformis (75.6%) showed the highest metal chelating effect. chloroform and ethyl acetate frac-tion of all the diatoms exhibited significant antioxidant activities in lipid peroxidation inhibitory activity. In particu-lar, both chloroform and the ethyl ecetate fraction from A. longipes and A. coffeaeformis exhibited lipid peroxidation inhibitory activity significantly higher than that of $\alpha$- tocopherol. These data suggest that the Jeju benthic diatoms tested are rich in hydrophilic and hydrophobic antioxidative compounds with different antioxidative properties that can be applied in food industry.

• 한국해양학회지:바다
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• 제8권4호
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• pp.420-425
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• 2003

부산 서암 조간대 부착생물군집의 종조성, 군집구조, 종다양성을 조사하였다. 부착해산식물의 출현종수는 남조류 4종, 녹조류 6종, 갈조류 17종, 홍조류 47종, 해산종자식물 l종으로 총 75종이 관찰되었다. 부착해산식물 우점종은 melobesioidean algae, Chondracanthus tenellus, Sargassium thunbergii, Corallina spp., Phyllospadix japonica 5 종이었고, 여름에 Ulva pertusa가 추가되는 경향을 보였다. 저서동물은 Chthamalus challengeri and Mytilus edulis 가 조간대 상부와 중부에 우점하는 단순한 분포를 보였다. 한편 해조군집의 종다양성지수는 빈도, 피도, 빈도와 피도 합 그리고 중요도를 기준으로 계산한 결과, 각각 1.81, 2.25, 2.19, 1.80로 나타났다. 이는 종다양성지수의 계산을 위한 기준자료에 따라 값이 달라짐을 의미하는 것으로, 차후 종다양서지수를 논할 때 기본자료 선택의 중요성과 방법론의 표준화가 필요함을 지적한 것이다. 한편 본 연구에서 분류된 해조류 종수는 부산연안에서 기 조사된 결과와 비교할 때 최고 65%까지 감소한 것으로 나타났다.

• ALGAE
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• 제22권1호
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• pp.45-52
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• 2007

An intertidal marine benthic algal vegetation and vertical distribution at Kangnung and it’s vicinity, the eastern coast of Korea was investigated to clarify the community structure and vertical distribution by quadrat method. Marine algae identified from the area were 116 species; 15 green, 31 brown and 70 red algae. The dominant species were Ulva pertusa, Codium fragile, Undaria pinnatifida, Dictyota dichotoma, Gelidium amansii, Corallina pilulifera, Carpopeltis affinis, Grateloupia filicina, Pachymeniopsis elliptica and Chondrus ocellatus at study sites. The vertical distribution of intertidal marine algae was divided into three distinct zones. They were characterized by Porphyra tenera at the upper, Enteromorpha spp. and Ulva pertusa at the middle, and Sargassum thunbergii, Hizikia fusiformis and Pachymeniopsis elliptica at the lower zones, respectively. The vertical distribution of subtidal zone algae were characterized by Laminaria spp. at 15m depth and Kjellmaniella crassifolia at 15 to 25 m depths, whereas Agarum cribrosum was dominant at the lower zone than 25 m depth.

• Ocean and Polar Research
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• 제25권4호
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• pp.569-591
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• 2003

Marine benthic flora was investigated in an Arctic bay. Specimens of chlorophyte, phaeophyte, and rhodophyte were collected and examined over the period from July to August 2003 from Kongsfjorden Spitsbergen in Svalbard Islands. A total of 28 genera and 32 species (5 chlorophytes, 18 phaeophytes, and 9 rhodophytes) was identified and described. A green alga Enteromorpha linza(Linnaeus) J. Agardh, a brown alga Asperococcus compresus Griffiths ex Hooker, and three red algae Gracilaria gracilis (Stackhouse) Steentoft et al., Rhodymenia pacifica Kylin and Schizochlaenion rhodotrichum Wynne et Norris were recorded in Svalbard Islands for the first time.

• ALGAE
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• 제19권3호
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• pp.257-270
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• 2004

In order to clarify the structure and seasonal dynamics of warm tolerant benthic marine algal community in Korea, the species composition and biomass of marine algae at the discharge canal of Uljin nuclear power plant on the East Coast of Korea were investigated seasonally from February 1992 to October 2000. 107 species of marine algae were found at the discharge canal during the past nine years. In general, the number of species observed was abundant in spring or summer and less in autumn or winter. 27 species (4 blue-green, 5 green, 6 brown and 12 red algae) of marine algae occurred more than 1/ 6 frequency and thus can be categorized as warm tolerant species. Among these, one brown (Dictyota dichotoma) and four red algae (Gelidium amansii, Anphiroa ephedraea, Hydrolithon sargassi, Marginisporum crassissimum) are recorded as warm tolerant marine algae for the first time in Korea. Padina arborescens, Anphiroa zonata and Corallina pilulifera were common species found more than 75% frequency. Seasonal fluctuations of mean biomass were 0-1,330 g dry wt m^(-2) and dominant species in biomass were Corallina pilulifera (contribution to a total biomass proportion 34%), Anphiroa zonata (23%), Padina arborescens (18%) and Sargassum micracanthum (11%). The red algae appeared as predominant algal group at the discharge canal of Uljin nuclear power plant in the qualitative and quantitative aspects. The green algae such as Enterornorpha compressa appeared rather frequently at the discharge canal, but the biomass proportion was very low, in contrast to Kori nuclear power plant where there was definite green algal dominance. Differences in algal communities developed at the discharge canals of Uljin and Kori nuclear power plant on the East Coast of Korea, particularly biomass proportions of green algae, can probably be related to local environmental factors such as water velocity through the canal and natural seawater temperatures.

• ALGAE
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• 제23권4호
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• pp.317-326
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• 2008

Marine algal flora and community structure were investigated seasonally at three sites in Ilkwang Bay on the southern east coast of Korea from May 2007 to February 2008. Total 103 species including 10 of green algae, 17 of brown algae, 76 of red algae were collected and identified. Among these species, 21 species were found throughout the year. Ulva pertusa, Enteromorpha linza, Grateloupia lanceolata, Chondracanthus intermedia and Caulacanthus ustulatus were distributed dominantly in upper intertidal zone. By contrast, crustose coralline algae, Grateloupia spp., Chondracanthus tenellus, Prionitis cornea and Sargassum spp. occurred predominantly in middle intertidal zone. Grateloupia spp., Sargassum spp., Ecklonia cava and Ulva pertusa were dominant in lower intertidal zone. Annual mean biomass in wet weight was 478.3 g m$^{-2}$. Maximum biomass was recorded in site 1 (731.8 g m$^{-2}$), and minimum was recorded in site 3 (78.5 g m$^{-2}$). The R/P, C/P and (R + C)/P value reflecting flora characteristics were 4.47, 0.59 and 5.06, respectively. Two groups produced by cluster analysis, one including sites 1, 2 and the other including site 3, showed meaningful difference in similarity, each other. Site 3 showed the limited species composition due to inflow of fresh water and absence of solid substratum. However, there was no significant difference between site 1 and site 2. In conclusion, the number of marine algae species and biomass in Ilkwang Bay were markedly reduced comparing with the previous studies. These suggest that a solution for reconstruction of the poor marine algal vegetation is considerably demanded.

• 한국수산과학회지
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• 제45권6호
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• pp.694-703
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• 2012

To understand the characteristics of sedimentary and benthic environments in habitats of naturally-occurring intertidal benthic macroalgae, various geochemical parameters of sediment (grain size, ignition loss [IL], chemical oxygen demand [COD], and acid volatile sulfur [AVS]) and pore water (temperature, salinity, pH, and nutrients) were measured in the southern intertidal zone of Hampyeong Bay at two month intervals from April to October 2009. Ecological characteristics including the distribution and biomass of benthic macroalgae were also investigated. Benthic macroalgae were distributed below 4 to 5 m depth from mean sea level near the lower portion of the intertidal zone where air exposure time is relatively short. The distribution area and biomass of benthic macroalgae gradually decreased during the study period. The surface sediments in the benthic algal region were mainly composed of finer sediments, such as slightly gravelly mud and mud. The temperature, salinity, pH, and nutrient concentrations (except dissolved inorganic nitrogen) in pore water did not differ in regions with and without benthic macroalgae, whereas the mean grain size and the concentrations of IL, COD, and AVS in sediments were much higher in regions harboring benthic macroalgae. The correlation between mean grain size and IL in sediments displayed two distinct gradients and the slope was much steeper in regions harboring benthic macroalgae, indicating that the content of organic matter in benthic algal region is not solely dependent on mean grain size. Our results indicate that the benthic macroalgae in the southern intertidal zone of Hampyeong Bay play an important role in the accumulation of organic matter in sediment.

• 해양환경안전학회지
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• 제15권3호
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• pp.179-185
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• 2009

마산만 조간대에서 서식하는 해조류 군집의 종조성 및 분포패턴을 2007년도에 계절별로 조사하였다. 조사기간 동안 총 42종의 해조류가 서식하였으며, 이 중 녹조류 5종, 갈조류 8종, 그리고 홍조류가 29종으로 나타났다. 우점종은 Enteromorpha linza, Ulva pertusa, Sargassum thunbergii, Gelidium amansii, G. divaricatum, Corallina pilulifera, Gracilaria textorii, 그리고 Polysiphonia morrowii으로 나타났다. 특히 우점종들은 수직분포가 뚜렷하였는데, 조간대 상부에는 U. pertusa, G. divaricatum가, 중부에는 E. intestinalis, E. linza, S. thunbergii, G. divaricatum이 우점하였다. 한편 하부에는 U. pertusa, Undaria pinnatifida, S. thunbergii, G. amansii, G. divaricatum, C. pilulifera이 주로 출현하였다. 조사기간 동안 출현한 출현종수는 계절 및 정점에 따라 변하였다. 겨울에 가장 많은 38종이 출현하였으며, 가을에는 28종으로 가장 적었다. 정점별로는 정점 4, 6에서 가장 많았으며, 정점 1, 2에서 가장 낮게 나타났다. 해조류 군집의 공간적 분포를 파악하기 위한 군집분석을 이용한 수지도 및 MDS 분석 결과에서는 해조류의 종조성 및 현존량이 각 정점의 지형적인 차이 및 조류, 해수의 움직임과 같은 물리해양학적인 특징에 의한 것으로 나타났다.

• ALGAE
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• 제22권4호
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• pp.313-318
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• 2007

Studies have been made of the species composition and community structure of benthic marine algae at intertidal zone and subtidal zone of Youngdo at Busan. In this area, a total of 69 marine algal species including 10 Chlorophyta, 17 Phaeophyta and 42 Rhodophyta was identified. Dominant species in coverage were Enteromorpha linza, Ulva pertusa, Gelidium divaricatum, Hildenbrandtia rubra and Chondrus ocellatus throughout the year. Enteromorpha linza, Ulva pertusa, Porphyra yezoensis, Gelidium divaricatum, Corallina pilulifera, Grateloupia elliptica and Chondrus ocellatus vertically distributed in intertidal zone, while Ecklonia stolonifera, Gelidium amansii, Prionitis cornea, Gracilaria textorii, Acrosorium polyneurum and Phycodrys fimbriata in subtidal zone. The vertical distribution of subtidal zone were characterized by Ecklonia stolonifera at 1 to 5 m depths. During a year, biomass and length of Ecklonia stolonifera gradually decreased from March to January, but increased from February. Zoosporangial sori were observed from September to December. In conclusion, number of species in this area was remarkably reduced as compared to the previous data at Busan and it’s vicinity.

• ALGAE
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• 제32권1호
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• pp.41-46
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• 2017

In rocky intertidal habitats, abiotic stress due to desiccation and thermal extremes increases with elevation because of tides. A study in Atlantic Canada showed that, at low elevations where conditions are benign due to the brief low tides, fucoid algal canopies (Ascophyllum nodosum and Fucus spp.) do not affect the structure of benthic communities. However, at middle and high elevations, where low tides last longer, fucoid canopies limit abiotic extremes and increase the richness (number of invertebrate and algal species, except fucoids) of benthic communities. Using the data from that study, this paper compares the intensity of facilitation and its importance (relative to all other sources of variation in richness) between middle and high elevations, which represent intermediate and high stress, respectively. Facilitation intensity was calculated as the percent increase in benthic richness between quadrats with low and high canopy cover, while the importance of facilitation was calculated as the percentage of variation in richness explained by canopy cover. Data for 689 quadrats spanning 350 km of coastline were used. Both the intensity and importance of facilitation were greater at middle elevations than at high elevations. As canopies do not affect benthic communities at low elevations, this study suggests that the facilitation-stress relationship at the community level is unimodal for this marine system. Such a pattern was found for some terrestrial systems dominated by canopy-forming plants. Thus, it might be ubiquitous in nature and, as further studies refine it, it might help to predict community-level facilitation depending on environmental stress.