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101.
4种海洋绿藻光合放氢特征的研究   总被引:5,自引:0,他引:5  
四爿藻(Tetraselmis sp.)、微绿球藻(Nannochloropsis occulata)、小球藻(Chlorella vulgaris)和扁藻(Ptatymonas subcordiformis)的放氢特点各不相同。在暗厌氧培养阶段,四爿藻和微绿球藻不释放氢气,小球藻和扁藻释放微量的氢气。随后的光照培养阶段中,4种海藻在天然海水中都释放氢气,四爿藻和小球藻在无硫海水中不释放氢气,而微绿球藻在无硫海水中释放的氢气比在天然海水中的少,扁藻在无硫海水中释放的氢气为天然海水中的10倍。在4种藻中。亚心型扁藻的光合放氢能力最高。解偶联剂CCCP(carbonyl cyanide m—chlorophenylhydrazone)对该4种藻的光合放氢的影响各不相同,并初步推测了扁藻光合放氢的速度限制因素。  相似文献   
102.
酞酸酯对龙须菜的生态毒理研究   总被引:2,自引:0,他引:2  
研究了酞酸酯类化合物对龙须菜(Gracilaria lemaneiformis)生长的影响以及酞酸酯在龙须菜体内的积累状况。结果表明,在邻苯二甲酸二甲酯(DMP)、邻苯二甲酸二乙酯(DEP)、邻苯二甲酸二丁酯(DBP)、邻苯二甲酯二异辛酯(DEHP)4种酞酸酯混合质量浓度为0.05,0.10,0.20和0.40 mg/L的暴露条件下,龙须菜的相对生长速率和叶绿素a含量均受到了明显影响。与对照组比较,在高质量浓度处理组(0.1~0.4 mg/L)中,两指标分别下降了18.4%~21.3%和10.4%~15.3%,致毒效应与酞酸酯暴露浓度呈正相关。在受控水体的暴露试验中,利用气相色谱(GC-FID)分析表明,4种酞酸酯类(DMP,DEP,DBP和DEHP)在龙须菜体内均有一定程度的积累,其残留量分别为0~0.14 mg/kg,0~0.83 mg/kg,0.11~1.89 mg/kg,0.01~10.4 mg/kg,其积累程度与酞酸酯分子结构相关,侧链较长的酞酸酯比侧链较短的积累量要大,并随处理浓度的增加和时间推移呈增加趋势。  相似文献   
103.
海洋微藻对UV-B辐射的生理生化响应   总被引:6,自引:0,他引:6  
用生理生化的方法研究了UV-B辐射对海洋微藻———小新月菱形藻(Nitzschia closte-rium)生理生化的影响。结果表明:(1)随着UV-B暴露时间的延长,UV-B辐射对藻的生长以及光合速率有抑制作用,并且时间越长,抑制作用越明显;(2)UV-B辐射使小新月菱形藻可溶性糖含量降低,而且在最初的2d,UV-B辐射使可溶性糖含量降低迅速,第4天的可溶性糖含量稍有所升高但与第2天相比差异不显著,UV-B辐射第6天,可溶性糖含量又迅速降低;(3)UV-B辐射的可溶性蛋白含量在第2天明显升高,随后又快速下降;(4)对照组的还原型谷胱甘肽(GSH)含量的变化随时间延长而升高,UV-B辐射第2天的GSH含量比初始状态(0d)的GSH含量稍有升高,但变化不明显,第2天之后,GSH含量随时间延长而快速降低;(5)对照组的过氧化物酶(POD)活性随时间延长而升高,UV-B辐射第2天的POD活性比初始状态(0d)的POD活性显著升高,第2天之后,POD活性随时间延长而快速降低。  相似文献   
104.
Inorganic carbon utilization in the non-calcifying marine microalgae,Nannochloropsis oculata, Phaeodactylum tricornutum andPorphyridium purpureum was compared with high- and low-calcifying strains ofEmiliania huxleyi grown in artificial seawater medium aerated with either air (0.03% V/V CO2) or CO2-free air. For high-calcifying strain ofE. oculata andP. tricornutem, similar growth patterns were observed in air-and CO2-free air-grown cultures.P. purpureum showed a less final cell density in CO2-free air than in air-grown culture. However, low-calcifying strain ofE. huxleyi was able to grow only in air-grown culture, but not in CO2-free air-grown culture. Measurements of alkalinity, pH, concentration of dissolved inorganic carbon (DIC) and free CO2 showed different patterns of DIC utilization. WithN. oculata, P. tricornutum andP. purpureum the pattern of DIC utilization was characterized by an increase of pH and a decrease of DIC but a constant alkalinity in the cultures aerated with air or CO2-free air, suggesting that bicarbonate utilization was concomitant with an efflux of OH. Both alkalinity and pH were maintained rather constant in air-grown culture of low-calcifying strain ofE. huxleyi, suggesting that diffusive entry of CO2 could meet the requirement of DIC for its photosynthesis and growth. High-calcifying strain ofE. huxleyi, however, showed a pattern of decrease of alkalinity and DIC but an almost constant pH, indicating that bicarbonate was the major form of inorganic carbon utilised by this organism and bicarbonate uptake is unlikely to be accompanied by an efflux of OH. The final pH values reached byN. oculata, P. tricornutum andP. purpureum in a closed system were 10.75, 10.60 and 9.85 respectively, showing that bicarbonate utilisation is concomitant with an efflux of OH. While the final pH of 8.4 in high-calcifyingE. huxleyi suggests that bicarbonate utilization was not accompanied by an efflux of OH. Contribution No. 3557 from the Institue of Oceanology, Chinese Academy of Sciences. This work was supported by NERC grant GRE3/7853 U. K. and partly supported by Bio-Engineering Center, SSTC 96-C01-05-01.  相似文献   
105.
INTRODUCTIONDimethylsulfide(DMS)anditsprecursordimethylsulfoniopropionate(DMSP)areofbiogenicorigin .DMSandDMSPconcentrationsshownoclearcorrelationwithplanktonbiomassorproductivityinsomesearegions.ThismaybeduetothefactthatfactorslikephytoplanktonspeciationandphysiologicalstatearemoreimportantthanalgalbiomassorproductivityincontrollingDMSlevelsinseawater (Barnardetal.,1 984 ) .TurnerandMalin (1 988)andAndreae (1 990 )suggestedthattheunderlyingreasonfortherelativelyhighabundancesofDM…  相似文献   
106.
研究海洋生态系统在调节全球变化中的作用,采用生态毒理学的方法研究了UV-B辐射增强对2种海洋微藻膜的损伤及其差异性。结果表明,随着UV-B辐射剂量的增加,叉鞭金藻(Dicrateriasp.)和三角褐指藻(Phaeodactylum tricornu-tum)的光合速率降低。同时,膜相对透性增大,细胞内H2O2含量上升,微粒体膜中磷脂减少,游离脂肪酸增加。表明UV-B辐射增强使2种微藻的膜受到了严重伤害,而且膜伤害的加剧与活性氧的积累和由此引发的膜脂脱酯化有关。2种微藻细胞匀浆中丙二醛(MDA)含量无显著变化,而微粒体膜的MDA含量随着UV-B辐射剂量的加大显著提高。这表明UV-B辐射增强对2种海洋微藻膜的损伤可能是由膜脂过氧化和脱酯化作用共同引起的。  相似文献   
107.
有害藻华(HAB)的发生、生态学影响和对策   总被引:12,自引:0,他引:12  
论述了有害藻华 (HAB)的含义、成因及其生态学影响 ,总结了目前有害藻华的治理方法。在此基础上 ,对今后赤潮研究的发展趋势作了预测 ,以期为赤潮的研究工作、预警预报和生态学防治及其防灾减灾提供借鉴。  相似文献   
108.
Abstract. Availability of food in the sediment can play an important role in determining the dynamics of deposit feeders. Generally the abundance of deposit feeders during winter and spring is related to an increase in the nutritive value of the sediment due to the concurrent microalgal peaks. This work investigated, in 1998, the seasonal variability patterns in the nutritive value of the sediment and in the abundance of two polychaetes, Desdemona ornata (Sabellidae: Fabriicinae) and Perinereis cultrifera (Nereididae), that probably feed on benthic microalgae. Previously, in 1997, these two species were abundant in winter and spring. During that winter, the amount of chlorophyll a in the sediment was quite variable due to grazing activities. Three manipulative field experiments were carried out in winter and spring (January, March and April 1998) to test the hypothesis that increasing the amount of chlorophyll a increases the nutritional value of the sediment and the abundance of Perinereis cultrifera and Desdemona ornata . The results indicated that the patterns of variability for these species and for chlorophyll a were similar to those observed in 1997. In plots where microalgal growth was stimulated experimentally, Perinereis cultrifera increased in January and Desdemona ornata increased in January and March. The role of food in regulating the abundances of Perinereis cultrifera and Desdemona ornata is discussed.  相似文献   
109.
为探讨UV-B辐射对海洋生态系统的影响,研究了短期(2d)UV-B辐射对金藻8701、小新月菱形藻和亚心形扁藻3种藻单养的敏感性比较以及长期(21d)UV-B辐射对3种藻混养的种间竞争性平衡的影响。实验表明,(1)UV-B条件下。单养和混养情况下,最敏感的藻是金藻8701,小新月菱形藻次之,亚心形扁藻最不敏感;(2)增强的UV-B为对UV-B具有高耐受力的亚心形扁藻提供了竞争优势,使种间竞争平衡向着有利于亚心形扁藻的方向发展,到第21天,UV-B辐射(2.88J/m^2,5.76J/m^2)的处理组中,亚心形扁藻成为优势种。  相似文献   
110.
ABSTRACT

Water is an important component of many recreational opportunities and New Zealand invests significant resources in recreational water quality (RWQ) monitoring to assess risks to public health. However, monitoring primarily focuses on microbiological hazards and RWQ is considerably broader than this. The goal of this study was to take a comprehensive approach to evaluating RWQ while exploring the potential for greater public involvement in monitoring. A popular river swimming site was co-monitored weekly by volunteers and a council field officer. The attributes monitored–water temperature, visual clarity, benthic cyanobacteria and filamentous periphyton cover, E. coli and rubbish–were identified from a volunteer workshop. There was good concordance between volunteer and council data suggesting that volunteer measurements can be considered reliable. This highlights the potential for volunteers, with professional support, including training and quality assurance, to extend council RWQ surveillance to additional monitoring sites while improving public engagement on water management.  相似文献   
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