• 제목/요약/키워드: Blooms

검색결과 459건 처리시간 0.027초

First record of red macroalgae bloom in Southern Atlantic Brazil

  • Martins, Mateus S.;Massocato, Thais F.;Horta, Paulo A.;Barufi, Jose Bonomi
    • ALGAE
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    • 제31권1호
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    • pp.33-39
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    • 2016
  • Blooms of macroalgae have grown over the planet in recent decades as a possible result of eutrophication of coastal waters. Visually, a bloom forming can be identified by dominant presence of an organism at the expense of others. In mid-January 2014, a forming bloom of red algae was detected on the beach of Garopaba, Santa Catarina State, Brazil. This aroused the interest of tourists and locals as well as the scientific community. Thus, the objective of this study was to characterize and quantify the photosynthetic floating organisms contributing to this phenomenon. In addition, we qualitatively compared algal composition of the bloom to those deposited in the post-beach area and the adjacent rocky shore community. Five sampling points in random patches of floating material were defined. At each point, five replicates were taken with a cube of 32,768 cm3, resulting in a total of 25 samples. Samples were collected in the inner area enclosed by a PVC quadrate of about 900 cm² from the shore and the specimens found in post-beach zone (wrack). Twenty-four taxa of macroalgae were found in the bloom, with Aglaothamnion uruguayense as the dominance one. Ten taxa were found on shore. Only four taxa were found in the post-beach area. The biomass estimated for A. uruguayense in the floating material was 8.35 tons with an estimated area of 52,770 m2 . It is possible that this huge biomass value of the bloom is related to the local nutrient intake, and our results reinforce the necessity of coastal integrative management initiatives.

북한강 수역에서 분리한 남조류 Anabaena circinalis 휴면포자 발아에 대한 환경요인의 영향 (Effects of Environmental Factors on Akinete Germination of Anabaena circinalis (Cyanobacteriaceae) Isolated from the North Han River, Korea)

  • 박채홍;임병진;유경아;박명환;황순진
    • 생태와환경
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    • 제47권4호
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    • pp.292-301
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    • 2014
  • Akinete germination may be a starting point of some akinete-producing cyanobacterial blooms in eutrophic freshwater systems. This study examined germinability of akinete of a cyanobacterium Anabaena circinalis isolated from the sediment of the North Han River (Cheongpyung Dam), Korea, under several environmental factors such as temperature ($5{\sim}25^{\circ}C$), light ($0{\sim}100{\mu}mol\;photons\;m^{-2}\;s^{-1}$), nutrients (nitrogen and phosphorus) and pH (5~12). The high germination rate appeared at high temperature: >55% at $25^{\circ}C$, followed by 15% at $15^{\circ}C$, $10^{\circ}C$ and 10% at $5^{\circ}C$. Low light intensity was favorable for akinete germination. Over 45% of germination occurred at low light intensities (5, 15 and $30{\mu}mol\;photons\;m^{-2}\;s^{-1}$), while less than 10% of germination occurred at both 50 and $100{\mu}mol\;photons\;m^{-2}\;s^{-1}$. No germination occurred in the dark condition. Akinete germination rate increased with nutrient (phosphorus and nitrogen) enrichment, and nitrogen addition showed greater effect on the germination compared to phosphorus addition. Akinetes germinated well at neutral or slightly alkaline pH condition (pH 7 and pH 8: >55%), but no germination was observed at pH 11~12. The present study demonstrates some favorable ambient conditions of Anabaena circinalis germination, which could provide useful information to study the germination conditions of other Anabaena species or akinete-forming algae and predict its bloom in eutrophic freshwaters.

애엽(艾葉) 추출(抽出) 약침(藥鍼)이 허혈성(虛血性) 손상(損傷)에 미치는 효과(效果) (Effects of FOLIUM ARTEMISIAE ARGYI' Herbal Acupuncture on the Expression of nNOS protein Following Transient Forebrain Ischemic Injury in Rats)

  • 최윤영;김재효;전문기;임정아;김경식;손인철
    • Korean Journal of Acupuncture
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    • 제21권1호
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    • pp.15-27
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    • 2004
  • Objectives : Acupuncture has been used to prevent and treat the cerebrovascular accident, such as a stroke, and many studies of acupuncture and moxibustion concerning to the stroke have been undertaken in the human and various animals. Also, herbal acupuncture, namely aqua acupuncture has been applied and developed to various diseases including the cerebrovascular accident. FOLIUM ARTEMISIAE ARGYI is the dry leaf of Artemisia argyi Levl. et Vant. collected in summer before the plant blooms and used to moxibustion and has been recommended for use as an analgesic and hemostatic. In this study, effects of FOLIUM ARTEMISIAE ARGYI (艾葉)' herbal acupuncture on the $LR_3$, namely Taechung on neuroprotection after the transient forebrain ischemia were investigated in Sprague-Dawely rats. Methods : Expressions of neuronal nitric oxide synthase (nNOS) protein in the hippocampus and cortex were observed at 2 hrs after transient forebrain ischemia by immunohistochemistry. Results : Expression of nNOS protein was increased in the hippocampus and cortex at 2 hrs after transient forebrain ischemia. However, pretreatment with FOLIUM ARTEMISIAE ARGYI' herbal acupuncture on $LR_3$ significantly decreased expression of nNOS protein protein compared to ischemia group. These features were observed in the motor cortex and the hippocampus. Conclusions : These results suggest that pretreatment with FOLIUM ARTEMISIAE ARGYI' herbal acupuncture on $LR_3$ inhibits the expression of nNOS protein induced by transient forebrain ischemia and may modulate excitatory toxicity of neuron related to neuronal cell death.

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Cell-meditated studies on blooming and growth of potentially ichthyotoxic Cochlodinium polykrikoides(Dinophyceae)

  • Cho, Eun-Seob
    • 해양환경안전학회:학술대회논문집
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    • 해양환경안전학회 2007년도 추계학술발표회
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    • pp.187-188
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    • 2007
  • The fluctuations of biochemical and molecular activities III the harmful dinoflagellate, Cochlodinium polykrikoides, depending on water temperatures, were studied. In genomic DNA concentration, a similar value of 0.6 was shown at $12^{\circ}C$ and $15^{\circ}C$, but significantly increasing DNA from $18^{\circ}C$ (p<0.05), with a maximum of 1.8 at $24^{\circ}C$. After$24^{\circ}C$, the DNA significantly decreased to 0.6. Likely, the concentrations of RNA and total protein were at their highest values of 1.7 and 0.07 g $mL^1$ at $24^{\circ}C$, respectively. In contrast to ONA, RNA and total protein began to increase at $15^{\circ}C$. Oxygen availability between lower and higher temperatures was significantly different and increased from $18^{\circ}C$ according to light intensity, regardless of wavelengths (p<0.05). At $24^{\circ}C$, the highest value of the maximum electron transport rate (ETRmax), ranging from 537.9 (Ch 1) to 602.5 mol electrons $g^{-1}$ Ch1 a $s^{-1}$ (Ch 4), was also shown. Nitrate reductase (NR) and ATPase activities were at their highest values of 0.11 mol $NO_2^-g^{-1}$ Ch1 a $h^{-1}$ and 0.78 pmol 100 $mg^{-1}$ $at^2$ $4^{\circ}C$, respectively. When the cells cultured at $15^{\circ}C$, NR and ATPase activities significantly increased compared to $12^{\circ}C$ (p<0.05). In an analysis of CHN, the concentration of C and N also significantly increased (p<0.05). However, at $27^{\circ}C$, most of the molecular and biochemical movements were much lower, compared to $24^{\circ}C$. These results suggest that C. polykrikoides is very sensitive biochemical and molecular activities depending on water temperatures. Possibly, it is desirable to estimate at $18^{\circ}C$ the initiation of the massive blooming development of C. polykrikoides. In nature, it will be very difficult to maintain the massive blooms after $24^{\circ}C$ because of the possibility of significantly decreasing the molecular movement and activity of C. polykrikoides.

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The Effect of Soil Textures on the Flowering characteristics and Green Manure Yield of Crimson Clover (Trifolium incarnatum L.) in Upland Soil

  • Cho, Hyeoun-Suk;Seo, Myung-Chul;Park, Tea-Sun;Kim, Jun-Hwan;Sang, Wan-gyu;Shin, Pyeong;Lee, Geon Hwi
    • 한국작물학회:학술대회논문집
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    • 한국작물학회 2017년도 9th Asian Crop Science Association conference
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    • pp.367-367
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    • 2017
  • Crimson clover, a legume crop, is a landscape crop and green manure crop that can be sowing in spring and autumn. Its red flower blooms in May, and serves various roles such as landscape composition, weeds suppressing, prevention of soil loss and nutrient on sloping land and supplying nitrogen and organic matter in soil. Thus, in order to utilize this crop in agriculture land, we evaluated the growth characteristics of crimson clover cultivated in four different soil textures, sand, sandy loam, loam, and clay loam. The nitrogen content of crimson clover was 15.8 g kg-1 and C/N rate was 20.3. Its growth was good in sandy loam and loam. Its plant height was 42.5 cm in sandy loam and 49.5 cm in loamy, respectively, which are approximately 20 cm longer than the sand and clay loam. The crimson clover in sandy loam and loam bloomed about seven days earlier than those in sand and clay loam. Regarding number of flower per hill and flower length, there were no difference between soil textures. Dry weight of crimson clover was 2.5 Mg ha-1, 2.3 Mg ha-1 each in sandy loam and loam. Therefore, it was approximately 0.8 ~ 1.1 Mg ha-1 higher than dry weight of sand and sandy loam. Plant height and dry weight of crimson clover was increased late harvest time. Nitrogen contribution were higher in loam and clay loam, when it was respectively 51.3 kg ha-1, 53.5 kg ha-1. Therefore, according to flowering properties and dry weight, the growth and development of crimson clover was finest in sandy loam and loam.

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유해조류 제어를 위한 두 가지 이상의 생물제재 및 효과 (Antialgal Interactions of Biological Control Agents on Cyanobacterium and Diatom Blooms in vitro)

  • 김백호;강윤호;최희진;가순규;한명수
    • 생태와환경
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    • 제38권4호통권114호
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    • pp.494-502
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    • 2005
  • 녹조대발생의 원인종인 남조 Microcystis aeruginosa와 규조 Stephanodiscus hantzschii 에 대한 살조 및 섭식능을 갖는 박테리아 및 섬모충을 각각 단독 및 혼합처리하고 살조능을 비교하였다. 먼저 남조 M. aeruginosa에 대하여 살조세균 Streptomyces neyagawensis와 섬모충 Stentor roeselii를단독 및 혼합처리한 결과, 각각의 단독처리가 혼합처리보다 더 높은 살조능을 나타내는 두 생물제재의 길항적 살조효과를 나타냈다. 또한 규조 S. hantzschii 에 대해 살조능을 갖는 박테리아 P seudomonas putida와 S. roeselii를 전과 동일한 방법으로 단독 및 혼합처리하여 결과를 비교하였다. 전 실험과는 다르게 두 생물제재의 혼합처리가 단독처리보다 더 높은 살조능을 보이는 두 생물제재의 상승적 살조효과를 나타냈다. 이러한 결과들은 녹조 제어를 위한 생물제재의 적용시 유용하게 이용될 것이며, 다양한 생물제재를 이용함으로서 수중생태계의 혼란을 초l소화시킬 수 있을 것으로 사료되었다.

남조류 Anabaena 휴면포자의 연구 동향 및 방향 (Current Status and Perspectives in the Akinete Study of the Blue-green Algal Genus Anabaena)

  • 강필구;이송지;변명섭;윤성애;김헌년;이재관;황순진
    • 생태와환경
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    • 제47권1호
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    • pp.1-12
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    • 2014
  • 남조류는 겨울철에 휴면포자의 형태로 퇴적층에서 존재하다가 적합한 환경조건이 되었을 때 다시 영양세포로 전환된다. 이렇게 전환된 영양세포는 성장에 적합한 환경이 되었을 때 대량증식 하게 되어 수체 내에서 우점한다. 이전까지의 국내 대부분의 연구는 수체 내 영양세포의 변동과 환경인자와의 관계 또는 영양세포에 대한 생리생태적 연구부분에 국한되었다. 하지만, 휴면포자에서 영양세포로 진행되는 부분에 대한 연구가 조류 대량증식의 궁극적인 기작이 되므로 휴면포자에 대한 연구는 조류의 생활사를 이해하는 데에도 매우 중요하다. 또한 다른 조류들간의 변동 및 천이의 연구를 위해서도 필수적이다.

$_L$ =lysine에 의한 Microcystis sp.의 선택적 성장억제 (The Effect of $_L$=lysine on Growth Inhibition of Microcystis sp.)

  • 송석환;신규철;한명수;최영길
    • 환경생물
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    • 제21권2호
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    • pp.216-221
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    • 2003
  • 본 연구는 $_L-lysine \; (_{-2}$, 6-Diaminohexanoic acid)의 영향을 받는 남조류와 남조류에 영향을 주는 $_L-lysine $의 농도를 파악 하고자 20종의 Microcystis.를 실험에 사용하였다. 남조류의 생장 억제 능력은 double-layered agar method와 microplate method를 이용하여 측정하였다. L-lysine의 농도를 100-${\mu}g\; ml-1~300 ${\mu}g\; ml^{-1}$이상에서 처리한 경우 Microcystis ichthyoblabe NIER-10021외 7종의 Microcystis sp.에서 투명대가 형성되었다. Microplate method서는10~500${\mu}g\; ml^{-1}$의 농도에서 생장억제 및 lysis를 나타내어TEk. 그리고 Microcystis viridis NIER-10020 외 3종은 10${\mu}g\; ml^{-1}$이하의 낮은 농도에서도 생장억제 및 분해를 나타내는 높은 활성을 보였다.

아산만 식물플랑크톤 군집의 월 변동 (Monthly Variation of Phytoplankton Community in Asan Bay, Korea)

  • 정병관;신용식;양성렬;박철
    • 한국해양학회지:바다
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    • 제16권4호
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    • pp.238-245
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    • 2011
  • 아산만 식물플랑크톤의 군집구조 변화를 파악하기 위하여 총 5개 정점을 선정하여 2008년 1월부터 12월까지 월별 조사를 실시하였다. 조사기간 동안 두 번에 걸쳐(2월, 8월) 식물플랑크톤 대발생이 발생하였고, 시기에 따라 발생 위치가 다르게 나타났다. 조사기간 동안 총 7개 분류군(Bacillariophyceae, Chlorophyceae, Chrysophyceae, Cryptophyceae, Cyanophyceae, Dinophyceae, Euglenophyceae) 134종이 출현하였다. 대체로 규조류(Bacillariophyceae)가 우세한 분포를 보였으나 하계에는 와편모조류가 증가하였고 내측해역보다는 외측해역에서 개체밀도가 높게 나타났다. 우점종과 차우점종 역시 규조류인 경우가 많았으나 6월부터 7월에는 와편모조류가 우점 및 차우점종으로 나타났다. 생태지수 분석결과 종다양성지수는 내측에서 외측으로 갈수록 높았으며 우점도지수는 상반된 결과를 나타내었다.

Population Development of the Dinoflagellates Ceratium furca and Ceratium fusus during Spring and Early Summer in Iwa Harbor, Sagami Bay, Japan

  • Baek, Seung-Ho;Shimode, Shinji;Han, Myung-Soo;Kikuchi, Tomohiko
    • Ocean Science Journal
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    • 제43권1호
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    • pp.49-59
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    • 2008
  • To examine the population development of the dinoflagellates, Ceratium furca and Ceratium fusus, daily field monitoring was conducted between April and July 2003 in the temperate coastal water of Sagami Bay, Japan. During the study period, the concentrations of C. furca were always lower than those of C. fusus. A sharp increase in the densities of both species was recorded on 5 May showing the maximum cell concentrations (C. furca = $14,800\;cells\;L^{-1}$, C. fusus = $49,600\;cells\;L^{-1}$). In the 7 days prior to the May bloom of the Ceratium species (29 April to 1 May), the highest density of the heterotrophic dinoflagellate Noctiluca scintillans was observed. Additionally, a second bloom of C. fusus occurred on 22 July. Here, two causes of the significant increases in the Ceratium populations during the two blooming periods (first time; 1 to 8 May, second time; 15 to 22 July) are presented. First, an increase in the nutrients of the surface layer regenerated by the breakdown of blooms by N.scintillans could be considered as a major cause of the population increase of the two Ceratium species. Second, a decrease in salinity (to 27 psu) was correlated with the later bloom of C. fusus. These results suggest that the population development of the two Ceratium species requires nutrients regenerated after the reduction of the diatom population by N. scintillans and, for C. fusus, continuous low salinity conditions, compared to other environmental factors during the rainy season.