• 한국지구과학회지
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• 제37권6호
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• pp.325-331
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• 2016

흑산 니질대에서 채취한 코어 퇴적물 HMB-103으로부터 규조를 분석하여 3개의 규조 군집대를 설정하였고, 산출된 한랭수종과 온난수종, 염분도에 의해서 고환경을 해석하였다. 규조는 총 41속 76종이 감정되었으며 규조 개체수 농도는 $0.1-15.4{\times}10^4g^{-1}$ 의 범위에 해당된다. 연구 결과, 약 45,000 yr B.P.경까지의 규조 군집대 I에서는 한랭수종의 산출이 많은 것으로 보아 한국연안류의 영향을 주로 받았으며, 14,000부터 11,646 yr B.P경까지의 규조 군집대 II는 규조의 산출이 거의 없는 추운 시기(Younger Dryas)로 생각된다. 그러나, 11,646 yr B.P부터 홀로세까지의 규조 군집대 III 시기에는 해수면이 상승하면서 황해 난류의 영향을 더 많이 받았다.

• Ocean and Polar Research
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• 제24권4호
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• pp.359-365
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• 2002

The qualitative and quantitative composition of the phytoplankton of the coastal waters off Vladivostok during the period 1991-1994 was studied. The following trends in the phytoplankton composition with decreasing distance from the source of eutrophication were revealed: 1) total density and bio-mass increased; 2) the density of the diatom Skeletonema costatum, which reflects a decrease in the Shannon-Weaver species diversity index during the summer microalgal bloom, increased significantly; and 3) the density of the non-diatom component of the phytoplankton increased.

• ALGAE
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• 제26권4호
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• pp.299-315
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• 2011

The morphology, taxonomy, and distribution of species belonging to the diatom family Rhizosoleniaceae were studied from the marine coastal waters of Korea. Rhizosolenid diatom taxa were collected at 30 sites from September 2008 to February 2010 and were analyzed by light and scanning electron microscopy. We identified 6 rhizosolenid genera, including Rhizosolenia, Proboscia, Pseudosolenia, Neocalyptrella, Guinardia, and Dactyliosolen. We describe 5 genera in this study, except Rhizosolenia. Five genera were compared in detail with congeneric species. Six genera within the family Rhizosoleniaceae were divided into two groups based on morphological diagnostic characters including valve shape, areolae pattern, the shape of external process, and girdle segments in the column. The first group had a conoidal valve and loculate areolae, which comprised Rhizosolenia, Proboscia, Pseudosolenia, and Neocalyptrella, and the second group of Guinardia and Dactyliosolen showed a flat or rounded valve and poroid areolae. Important key diagnostic characters were based on valve shape, areolae pattern on the segment, external process, position of the tube, and the valve margin. D. phuketensis was new to Korean coastal waters.

• ALGAE
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• 제25권2호
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• pp.57-64
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• 2010

A variety of Cyclotella atomus were discovered among the epiphytic diatoms on eelgrass (Zostera marina L.) in Korean waters. Cyclotella atomus var. marina has a flat and disc-shaped valve, and is clearly differentiated into a striate marginal zone and a smooth central zone. The valves have a very small diameter ranging from 3.1-3.4 ${\mu}m$. This small diatom does not have any central ornamentation. The marginal striate zone has numerous granules toward the mantle. The valves have five or six marginal fultoportulae with two satellite pores and a single marginal rimoportula.

• Bulletin of the Korean Chemical Society
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• 제34권2호
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• pp.353-354
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• 2013

• ALGAE
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• 제25권3호
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• pp.133-140
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• 2010

Using chlorophyll fluorescence, the vertical migration of benthic diatoms responding to light intensity and affected by sediment grain size was studied. Minimal fluorescence ($F_o$) of surface sediment was measured by imaging pulse amplitude modulated (Imaging-PAM) fluorometer, and used to monitor diatom biomass variation in surface sediments. The test diatoms, Amphora coffeaeformis (C. Agardh) K$\ddot{u}$tzing and Cylindrotheca closterium (Ehrenberg) Reimann & Lewin, migrated to the sediment surface under irradiance from 50 to 500 ${\mu}mol$ photons $m^{-2}s^{-1}$. However, the diatoms exhibited no evident increase of surface biomass under dark conditions, and even showed slightly decrease of surface biomass under irradiances over 1,000 ${\mu}mol$ photons $m^{-2}s^{-1}$. The light intensity inducing the maximum surface migration of A. coffeaeformis was 100 ${\mu}mol$ photons $m^{-2}s^{-1}$, while the light intensity producing the same effect for C. closterium was 250 ${\mu}mol$ photons $m^{-2}s^{-1}$. C. closterium showed higher motility than A. coffeaeformis. Faster diatom surfacing was observed in larger grain size sediments (125-335 ${\mu}m$) than smaller ones (63-125 ${\mu}m$). This study confirmed the significant influence of light as a main triggering factor behind migration, indicated the distinct effect of different sediment grain size, and highlighted the species-specific migratory ability.

• 미생물학회지
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• 제52권3호
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• pp.306-312
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• 2016

미세조류는 수환경으로 유입되는 독성물질의 배출기준을 설정하거나 환경영향을 평가하기 위한 환경변화의 잠재적 생물지표이다. 본 논문에서 해양 미세조류인 녹조류 Tetraselmis suecica, 규조류 Ditylum brightwellii, 와편모조류 Prorocentrum minimum에 대한 내분비 교란물질(EDCs) 비스페놀 A (BPA)와 Aroclor 1016의 영향을 평가하였다. 처리한 EDCs에 대하여 각각의 종은 매우 다른 민감도 차이를 보였다. 각 종에 대한 50% 영향농도($EC_{50}$)는 Aroclor 1016가 BPA보다 더 유해하였다. 실험에 사용한 미세조류중에서 규조류 D. birghtwellii(0.037 mg/L BPA과 0.002 mg/L Aroclor 1016)가 다른 종보다 매우 민감하게 반응하는 것으로 조사되었다. 본 연구 결과는 수서생태계에로 배출되는 기준 농도 이상의 EDCs가 해양 생물에게 유해 효과가 있다는 것을 제시해 준다.

• Journal of Ecology and Environment
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• 제38권4호
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• pp.545-562
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• 2015

A study on indigenous diatoms was carried out at 71 sites during the period from April 1999 to August 2014 in marine and fresh water in Korea. Forty species of diatoms are new to Korea and they are divided into three classes, six subclasses, 13 orders, 19 families, and 28 genera. The nomenclatures, references, dimensions, specimens examined, local habitat, distribution in Korea, and photograph are reported here. The 40 species found in marine and fresh water showed speciesspecific habitats.

• ALGAE
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• 제30권2호
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• pp.103-119
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• 2015

Photosynthetic rates of the large centric diatom Coscinodiscus granii were measured by means of multicolor variable chlorophyll fluorescence imaging, single cell $^{14}C$ assimilation, and optical $O_2$ sensor measurements during light acclimatization of cultures grown at five different irradiances: 50, 150, 235, 332, and $450{\mu}mol$ photons $m^{-2}\;s^{-1}$. Photo-acclimatization was evident from changes of cellular chlorophyll a content, growth rates, and light response curves. Each of the applied methods evaluates different parts and reactions in the photosynthetic apparatus, which makes a direct quantitative comparison of rates difficult, although a different degree of correlation were found between all three methods. However, when used in combination, they provide information about the internal relationship of photosynthetic pathways as well as the variation in photosynthetic capacity between individual cells within a single algal culture.

• ALGAE
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• 제25권2호
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• pp.65-70
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• 2010

The genus Chaetoceros provides highly diversified diatoms in marine systems. Morphological descriptions of the genus are well-documented, yet the DNA taxonomy of Chaetoceros has not been satisfactorily established. Here, the molecular divergences of the 18S-28S rDNA of Chaetoceros were assessed. DNA similarities were relatively low in both 18S (93.1 $\pm$ 3.9%) and 28S rDNA (81.0 $\pm$ 4.6%). Phylogenies of the 18S, 28S rDNAs showed that Chaetoceros was divided according to individual species, clustering the same species into single clades. Statistical analysis with corrected genetic (p-) distance scores showed that nucleotide divergence of Chaetoceros 28S rDNA significantly differed from that of 18S rDNA (Student's t-test, p < 0.05). This finding suggests that the 28S rDNA may be treated as a more suitable marker for species-level taxonomic distinctions of Chaetoceros.