• 제목/요약/키워드: diatoms

검색결과 508건 처리시간 0.024초

가마미 해수욕장(전남 영광) 갯벌의 미세조류의 분포에 관한 연구 (Studies on the Distribution of the Microalgae in the Tidal Flats of Gamami Beach, Young-Gwang, Korea)

  • 이학영
    • 한국환경과학회지
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    • 제12권7호
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    • pp.715-724
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    • 2003
  • Distributional patterns of microalgae were studied in the tidal flats of Gamami Beach(Young-Gwang, Korea) from November 1999 to 2000 July. The tidal flats of Gamami Beach was composed mainly of sandy sediment. The concentrations of nutrients were low compared with other tidal flats. In the present study, 68 species of microalgal flora were identified. These were comprised of 25 species of benthic microalgae and 59 species of planktonic microalgae. Diatoms predominated the benthic microalgae with 96.0% of total species occurred. Dominant species were Amphora sp., Cocconeis sp., Coscinodiscus asteromphalus, Coscinodiscus sp., Nitzschia sigma var. intermedia, Nitzschia distans, Navicula spp., Paralia sulcata, Pleurosigma sp. Skeletonema coastatum, and Surirella sp. Among them, Amphora sp., Paralia sulcata, and species of Pleurosigma and Nitzschia were observed throughout the studied period. Planktonic microalgae of Gamami Beach was also predominated by diatoms. They occupied 88.1% of total planktonic microalgae. The density of microalgal population was higher in silty sediment than in sandy sediment. The population density of microalgae was higher in high tide zone than that in low tide zone. The density of the benthic microalgae in the surface layer of tidal flats showed increasing tendency for 2 hours after the beginning of ebb tide. On the contrary, benthic microalgal density of subsurface layer was decreased during the period. Concentrations of chlorophyll ${\alpha}$ from sediment and water were not synchronized during the study period. Therefore, the distributional patterns of the benthic microalgae and planktonic algae seemed not to be related. Chlorophyll ${\alpha}$ of water was highly related with the concentration of NH$_4$-N, whereas, chlorophyll ${\alpha}$ of sediment uas related with NO$_3$-N concentration.

실해역 환경에서 생물부착에 관한 기초실험 연구 (Preliminary Experimental Study on Biofouling in Real Sea Environment)

  • 정동호;김아리;문덕수;이승원;김현주;함윤호
    • 한국해양공학회지
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    • 제23권6호
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    • pp.39-43
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    • 2009
  • A flow and low temperature of deep seawater the biofouling properties in a seawater environment of different materials, such as a steel pipe, polyethylene pipe, and nylon net, used for ocean industries. Experiments in a real sea environment were performed to grasp the quantitative and qualitative biofouling from diatoms attached to materials by measuring the Chlorophyll-a density. Experimental samples were placed under five types of ocean environmental conditions and analyzed every month for five months. It is shown that the biofouling by diatoms was strongly affected by the seawater temperature for all of the experimental samples. It was found that diatoms mainly adhered to the nylon net, while crustaceans prefer polyethylene, under a high temperature condition. It is believed that the biofouling properties are strongly related to the surface roughness of a material. The biofouling under the low temperature condition of deep seawater was rare and stable for the experimental periods. The inside of a pipe conveying deep seawater can be presumed to remain clear without biofouling on the condition of a flow and low temperature of deep seawater.

한강하류의 환경학적 연구 -VII. 식물플랑크톤군집의 장기간 변화와 전망- (Environmental Studies in the Lower Part of the Han River -VII. Long Term Variations and Prospect of the Phytoplankton Community-)

  • 이진환;정승원
    • ALGAE
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    • 제19권4호
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    • pp.321-327
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    • 2004
  • The literature review on the dynamics of the phytoplankton communities in terms of species composition, standing crops, abundant species and dominant species in the lower part of the Han River from 1940s to 2000s was conducted for the prospective prediction of their succession patterns. Total of 326 taxa were identified and they belonged to 47 blue-green algae, 139 green algae, 12 euglenoids, 126 diatoms, 6 din flagellates and 2 silicoflagellates. Composition of phytoplankton communities were 83.6% diatoms, 10.5% blue-green algae and 5.3% green algae in the middle of 1960s, whereas those were 43.2% diatoms, 40.7% green algae and 13.6% blue-green algae in the 1990s. Before 1990s, Synedra ulna, Melosira varians, Cymbella tumida, Synedra acus, Cymbella ventricosa, Navicula cryptocephala, Nitzschia palea, Aulacoseira granulata, Gomphonema parvulum and Cymbella affinis were most frequent, while those after 1990 were Asterionella formosa, Asterionella gracillima, Aulacoseira granulate, Aulacoseira granulata var. angustissima, Chlorella vulgare, Fragilaria crotonensis and Synedra ulna. Phytoplankton blooms were frequent from winter to the late spring and rare in summer due to heavy rain and discharge. Seasonal variations of the dominant species were fairly obvious; Asterionella gracillima and Aulacoseira granulata in spring, Aulacoseira granulate and Aulacoseira granulate var. angustissima in summer and autumn, Asterionella gracillima and Stephan discus hantzschii in winter. Recently blue-green algae, Microcystis, Aphanocapsa, Dactylococcopsis have been more abundant than those of the previous reports. Based on the current situations, Stephan discus hantzschii f. tennis, Asterionella gracillima, Aulacoseira granulate and blue-green algae will be more abundant and blooms of those species will be more frequent.

Screening of High Temperature-Tolerant Oleaginous Diatoms

  • Zhang, Lingxiang;Hu, Fan;Wan, Xiu;Pan, Yufang;Hu, Hanhua
    • Journal of Microbiology and Biotechnology
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    • 제30권7호
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    • pp.1072-1081
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    • 2020
  • Screening suitable strains with high temperature adaptability is of great importance for reducing the cost of temperature control in microalgae cultivation, especially in summer. To obtain high temperature-tolerant diatoms, water samples were collected in summer from 7 different regions of China across the Northeast, North and East. A total of 731 water samples was collected and from them 131 diatom strains were isolated and identified based on the 18S rRNA sequences. Forty-nine strains out of the 131 diatoms could survive at 30℃, and 6 strains with relatively high biomass and lipid content at high temperature were selected and were found to be able to grow at 35℃. Cyclotella sp. HB162 had the highest dry biomass of 0.46 g/l and relatively high triacylglycerol (TAG) content of 237.4 mg/g dry biomass. The highest TAG content of 246.4 mg/g dry biomass was obtained in Fistulifera sp. HB236, while Nitzschia palea HB170 had high dry biomass (0.33 g/l) but relatively low TAG content (105.9 mg/g dry biomass). N. palea HB170 and Fistulifera sp. HB236 presented relatively stable growth rates and lipid yields under fluctuating temperatures ranging from 28 to 35℃, while Cyclotella HB162 maintained high lipid yield at temperatures below 25℃. The percentage of saturated fatty acids and monounsaturated fatty acids in all the 6 strains was 84-91% in total lipids and 90-94% in TAGs, which makes them the ideal feedstock for biodiesel.

Seasonal Variation of Phytoplankton Community Structure in NortheasternCoastal Waters off the Korean Peninsula

  • Kang, Yeon-Shik;Choi, Hyu-Chang;Noh, Jae-Hoon;Choi, Joong-Ki;Jeon, In-Seong
    • ALGAE
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    • 제21권1호
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    • pp.83-90
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    • 2006
  • Phytoplankton community in the coastal waters off the northeastern Korean Peninsula were characterized from May 2002 to August 2003. Taxonomic composition, abundance and biomass were determined at two water depths at 10 sample sites. A total of 153 phytoplankton species including 121 diatoms, 28 dinoflagellates, 7 green algae and 7 other species were identified. The mean abundance of phytoplankton varied from 15 to 430 cells mL–1 in the surface layer and from 11 to 545 cells mL–1 in the bottom layer, respectively. Phytoplankton was more abundant in coastal stations relative to those in more open ocean. The most dominant species were marine diatoms such as Thalassionema nitzschioides, Licmorphora abbreviata, Chaetoceros affinis and Chaetoceros socialis. In addition, a few limnotic diatoms including Fragilaria capucina v. rumpens, the green alga Scenedesmus dimorphus, some marine dinoflagellates and Cryptomonas sp. appeared as dominant species. Mean concentration of total chlorophyll-a varied from 0.22 to 7.87 μg chl-a L–1 and from 0.45 to 6.79 μg chl-a L–1 in the surface and bottom layers, respectively. The contribution of phytoplankton each size-fractionated varied highly with season. The contribution of microphytoplankton to total biomass of phytoplankton in the surface and bottom layer was high in February and August 2003, and that of nano-phytoplankton was high in May 2002 in both surface and bottom layers.

견운모와 규조토에 대한 암모니아 기체의 흡착특성 (Adsorption characteristics of the sericite and diatomite for ammonia gas)

  • 이수승;김진수;윤창연;이종협
    • 청정기술
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    • 제12권3호
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    • pp.175-181
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    • 2006
  • 실내 공기오염 방지를 위하여 견운모와 규조토를 건축내장재로 사용하기 위한 물리 화학적 특성을 조사 하였다. 특히 규조토의 경우 주사전자현미경(Scanning Electron Microscope: SEM)으로 표면에 분포하는 규조화석의 존재를 확인하였으며, 질소흡탈착법(Brunauer-Emmett-Teller (BET) method)을 통해 5 nm 이하의 기공이 고르게 분포하고 비교적 넓은 비표면적을 가지는 것을 알 수 있었다. 이러한 규조토와 비교하여 견운모는 기공특성이 보이지 않았으며 비표면적 역시 상대적으로 작은 것으로 나타났다. 따라서, 다공질 구조와 넓은 비표면적으로 인해 규조토가 견운모보다 상대적으로 높은 흡착특성을 가지고 있음을 예상 하였으며, 이를 실험적으로 확인 하였다. 하지만 $950^{\circ}C$이상으로 열처리한 결과 규조토는 다공질 규조화석의 연소 및 무기성분의 고온소결로 인해 더 이상 기공 구조를 보이지 않고 비표면적이 감소하였으며, 그 결과 흡착성능 또한 감소하는 경향을 보였다. 결론적으로, 열처리 하지 않은 규조토의 경우 규조화석의 존재로 인해 다공질 구조를 가지며, 넓은 비표면적에 의해 보다 높은 암모니아 흡착특성을 보여 실제로 이와 같은 유해 화합물을 효과적으로 제거할 수 있는 능력이 있음을 보였다.

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동중국해 식물플랑크톤 군집의 공간분포와 와편모조류 적조 (Spatial Distribution of Phytoplankton Community and Red Tide of Dinoflagellate, Prorocentrum donghaience in the East China Sea during Early Summer)

  • 윤양호;박종식;서호영;황두진
    • 환경생물
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    • 제21권2호
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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.

여름철 남해도 연안 식물플랑크톤 군집 구조의 단기 변화 (Short-term Changes of Community Structure of Phytoplankton in Summer Around Namhae Island of Korea)

  • 임월애;강창근;김숙양;이삼근;김학균;정익교
    • ALGAE
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    • 제18권1호
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    • pp.49-58
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    • 2003
  • The short-term dynamics of the summer phytoplankton community structure were investigated in coastal waters around Namhae Island, the Southern Sea of Korea. The study was based on a comprehensive survey constituting 39 collections from 13 stations on July 18-22, August 1-2, 14-16 and 27-30, respectively. The community structure was analysed using cluster analysis and important environmental correlates of the assemblage structure were identified with canonical correspondence analysis (CCA). Water temperature, salinity, NO₂, NO₃, NH₄, PO₄, chlorophyll a and transparency were measured as physico-chemical environmental factors which may be associated with the phytoplankton community structure. Variations of salinity and concentrations of NO₃ and chlorophyll a were not significant. In addition to warmer water temperature, concentrations of NO₂, NO₄and PO₄ decreased at the beginning of August. And transparency was deeper and water column became very unstable after the middle of August. A wide taxonomic diversity was encountered during the survey, including a total of 121 taxa which was composed of 72 diatoms, 48 dinoflagellates and 1 euglenoid species. Cluster analysis showed that the Phytoplankton community could be divided into 4 distinct groups, indicating rapid changes of the community in the short course of this survey. These phytoplankton groups also showed distinctive dispersion patterns in 2-dimensional canonical space, indicating distinct groupings for stations at each survey. Dominant taxa of diatoms (Chaetoceros curvisetus, Chaetoceros spp., Leptocylindrus danicus, Leptocylindrus mediteraneus, Skeletonema costanum, and Pseudo-nitzschia pungen) clustered in region of CCA space corresponding to stations surveyed at the middle of July. Dominant taxa of dinoflagellates were tightly associated with stations surveyed at the middle (Karenia breve) and end (Cochlodinium polykrikoides and Polykrikos schwartzii) of August. The CCA also showed that the phytoplankton community compositions were highly associated with water temperature, transparency, NO₂, NH₄ and PO₄, suggesting that gradients in physical and nutrient conditions affect short-term changes in phytoplankton composition.

서해산 김 엽체상의 미소생물과 김의 병해와의 관계에 대한 연구 1 . 부착규조류와 주변해수의 식물플랑크톤의 종 조성 및 현존량 (A Study on the relationships between the epiphytic microbes and the blight of Porphyra species from the coastal waters of the Yellow Sea, Korea 1 . Species composition and standing stocks of epiphytic diatom and ambient water phytoplankton)

  • 김중래;신윤근;이건형;이원호
    • 한국수산과학회지
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    • 제24권1호
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    • pp.79-88
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    • 1991
  • 김의 병해를 일으키는 부착규조류와 주변해수의 식물플랑크톤의 분포양상을 조사하고자 개야도, 편포, 목포 등 세곳에서 1989년 2월부터 1990년 3월까지 시료를 채집하였다. 본 연구에서 동정된 부착 규조류는 40종이며 우점종은 Licmophora dalmatica, L. abbreviate, Melosira nummuloides, Paralia sulcata, Achnanthes javanica var. subconstricta, Grammatophora oceanica, Navicula sp., Synedra sp., Pinnularia sp., Fragitaia striatula, Cocconeis scutellum var. parva 등이었는데 그 중 Licmophora dalmatica가 가장 우점하였다. 주변해수의 식물플랑크톤 현존량은 서해 다른 연안에 비해 비교적 높은 수준이었다. 격포와 개야도의 부착규조류, 주변해수의 식물플랑크톤 상은 유사하였으나 목포의 경우는 다른 양상을 보였다.

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한국해역의 식물플랭크톤의 연구. III. 1967년 5월 북동부 한국해협 표층수의 식물플랭크톤의 양과 분포 (Phytoplankton Studies in Korean Waters. III. Surface Phytoplankton Survey of the North-Eastern Korea Strait in May of 1967)

  • 최상
    • 한국해양학회지
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    • 제4권1호
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    • pp.1-8
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    • 1969
  • 1967년 5월에 교통부 수로국 조사선 제1수로호(240톤)는 C.S.K.조사의 일환으로서 주로 해역의 단기간동안의 각종 해양요인의 변동상황을 관찰하는 목적으로 한국해협과 동해가 연속되는 207, 208정선을 동일코스로 이차에 걸쳐 횡단관측을 하였으며, 이때에 얻은 표층의 식물성 플랭크톤을 조사하는 기회를 갖었었다. 제1차 관측은 5월초순에, 제2차 관측은 5월하순에 실시되었으며, 두 관측의 시일차는 19일간이었다. 그러나 이러한 단기간의 시일간에도 나타난 식물성 플랭크톤의 종류상과 분포상에 적지않은 변화가 있었으며, 이것은 이 해역의 해양사항의 특수성을 나타내는 하나의 자료로서 흥미가 있었기에 여기에 그 결과를 보고한다.

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