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1.
海洋中二甲基硫的生物生产与消费过程   总被引:4,自引:0,他引:4  
DMS是海洋中最主要的挥发性有机硫化物,对全球气候变化和环境酸化产生重要影响。DMS的生物生产与消耗主要发生在海洋真光层。生物的生产与消耗被认为是海洋中DMS的主要来源和去除途径。海洋中DMS的生物生产和消耗是密切相关的,两者的速率基本保持平衡。目前,有关DMS生物生产与消费速率的测定方法有放射性同位素示踪和加抑制剂2种,后者颇受青睐,不过有关抑制机理还需进一步的研究。  相似文献   
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于2010年7~11月对胶州湾夏、秋季浮游动物种类和丰度进行现场调查,并分析讨论了胶州湾夏、秋季浮游动物丰度的水平分布与环境因子(温度、盐度、水深、叶绿素a)和二甲基硫(DMS)、溶解态β-二甲基巯基丙酸内盐(DMSPd)、颗粒态β-二甲基巯基丙酸内盐(DMSPp)的相关性。结果表明,胶州湾浮游动物丰度分布不均匀,8月湾内西部沿岸海域C1站位出现调查期间的动物丰度最大值(656.1ind/m3),最小值(1.492ind/m3)出现在10月胶州湾东北部的A2站位。浮游动物丰度具有明显的季节变化,秋季浮游动物丰度低于夏季浮游动物丰度。浮游动物丰度与盐度、叶绿素a含量、细菌生物量的相关性不明显,2010年10月浮游动物丰度与DMS呈显著正相关(P0.05),11月的浮游动物丰度与DMSPp呈显著正相关(P0.05),其它月份(7、8、9月)的浮游动物丰度与DMS、DMSPd、DMSPp浓度的相关性均不明显。由于浮游动物摄食活动对DMS释放的影响受多种因素的制约,因此浮游动物与DMS的相互作用需要进一步研究。  相似文献   
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INTRODUCTIONDimethylsulfide(DMS)anditsprecursordimethylsulfoniopropionate(DMSP)areofbiogenicorigin .DMSandDMSPconcentrationsshownoclearcorrelationwithplanktonbiomassorproductivityinsomesearegions.ThismaybeduetothefactthatfactorslikephytoplanktonspeciationandphysiologicalstatearemoreimportantthanalgalbiomassorproductivityincontrollingDMSlevelsinseawater (Barnardetal.,1 984 ) .TurnerandMalin (1 988)andAndreae (1 990 )suggestedthattheunderlyingreasonfortherelativelyhighabundancesofDM…  相似文献   
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The coastal ecosystems are highly sensitive to climate change and are usually influenced by variations in phytoplankton communities and water physiochemical factors. In the present study, the phytoplankton community, chlorophyll a(Chl a) and their relationships with environmental variables and dimethylsulfide(DMS) and dimethylsulfoniopropionate(DMSP) were investigated in spring 2017(March 24 to April 16) in the East China Sea(26.0°–33.0°N, 120.0°–128.0°E) and southern Yellow Sea(31.0°–36.0°N, 12...  相似文献   
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The distributions of DMS and its precursor dimethylsulfoniopropionate, in both dissolved (DMSPd) and particulate fractions (DMSPp) were determined in the seasurface microlayer and corresponding subsurface water of the Jiaozhou Bay, China and its adjacent area in May and August 2006. The concentrations of all these components showed a clear seasonal variation, with higher concentrations occurring in summer. This can be mainly attributed to the higher phytoplankton biomass observed in summer. Simultaneously, the enrichment extents of DMSPd and DMSPp in the microlayer also exhibited seasonal changes, with higher values in spring and lower ones in summer. Higher water temperature and stronger radiant intensity in summer can enhance their solubility and photochemical reaction in the microlayer water, reducing their enrichment factors (the ratio of concentration in the microlayer to that in the corresponding subsurface water). A statistically significant relationship was found between the microlayer and subsurface water concentrations of DMS, DMSP and chlorophyll a, demonstrating that the biogenic materials in the microlayer come primarily from the underlying water. Moreover, our data show that the concentrations of DMSPp and DMS were significantly correlated with the levels of chlorophyll a, indicating that phytoplankton biomass might play an important role in controlling the distributions of biogenic sulfurs in the study area. The ratios of DMS/chlorophyll a and DMSPp/chlorophyll a varied little from spring to summer, suggesting that there was no obvious change in the proportion of DMSP producers in the phytoplankton community. The mean sea-to-air flux of DMS from the study area was estimated to be 5.70 μmol/(m2·d), which highlights the effects of human impacts on DMS emission.  相似文献   
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The production of dimethylsulfide (DMS) and dimethylsulfoniopropionate (DMSP) by marine microalgae was investigated to elucidate more on the role of marine phytoplankton in ocean-atmosphere interactions in the global biogeochemical sulfur cycle.Axenic laboratory cultures of four marine microalgae–Isochrysis galbana 8701,Pavlova viridis,Platymonas sp.and Chlorella were tested for DMSP production and conversion into DMS.Among these four microalgae,Isochrysis galbana 8701 and Pavlova viridis are two species of Haptophyta,while Chlorella and Platymonas sp.belong to Chlorophyta.The results demonstrate that the four algae can produce various amounts of DMS(P),and their DMS(P) production was species specific.With similar cell size,more DMS was released by Haptophyta than that by Chlorophyta.DMS and dissolved DMSP (DMSPd) concentrations in algal cultures varied significantly during their life cycles.The highest release of DMS appeared in the senescent period for all the four algae.Variations in DMSP concentrations were in strong compliance with variations in algal cell densities during the growing period.A highly significant correlation was observed between the DMS and DMSPd concentrations in algal cultures,and there was a time lag for the variation trend of the DMS concentrations as compared with that of the DMSPd.The consistency of variation patterns of DMS and DMSPd implies that the DMSPd produced by phytoplankton cells has a marked effect on the production of DMS.In the present study,the authors’ results specify the significant contribution of the marine phytoplankton to DMS(P) production and the importance of biological control of DMS concentrations in oceanic water.  相似文献   
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本研究首次探究了西太平洋雅浦海沟北段从表层到超深渊海水中甲烷(CH4)及二甲基硫(DMS)的前体物质二甲基巯基丙酸内盐(DMSP)的浓度变化情况。结果表明:雅浦海沟海水甲烷浓度变化范围为1.49~3.87 nmol/L。其上层海水甲烷平均浓度最高,有明显的次表层极大现象。雅浦海沟氧最小层海水的甲烷平均浓度最低;在500~1 000 m中层水中甲烷浓度有一定程度的增大,1 000 m以下至底层甲烷浓度继续升高。研究海区溶解态DMSP(DMSPd)和总DMSP(DMSPt)平均浓度的垂直变化随深度呈先增大后减小趋势,颗粒态DMSP(DMSPp)的平均浓度随深度呈波动式变化,在中层达到最大。雅浦海沟CH4和DMSP浓度垂直变化受浮游生物、微生物、光照、温度、压力、大洋环流等的复杂影响。在真光层海水中,CH4浓度与DMSPd、DMSPp和DMSPt浓度表现为负相关关系,在200 m至底层海水中,CH4浓度与DMSPd、DMSPp和DMSPt浓度表现为正相关关系,显示光照条件是造成雅浦海沟不同深度海水CH4和DMSP浓度相关性差异的关键因素。  相似文献   
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一种二甲基硫化合物硫代甜菜碱(DMSP)成为环境科学和水产科学共同关注的热点之一。研究表明,DMSP是海洋植物产生的渗透调节物质,大量存在于海藻和盐生高等植物体内。含有DMSP的生物体死亡之后,DMSP被海洋细菌的二甲硫醚生成酶降解,生成二甲硫醚(DMS)和丙烯酸。DMS从海洋水面逾出,进入大气形成酸雨;由于DMS能形成云,所以有降低温室效应的作用。DMSP本身则对哺乳动物、禽类及水产动物(鱼和虾)的营养代谢有促进作用。酶学研究表明,动物肝脏中的两种硫甲基转移酶能把DMSP分子中硫原子上的甲基转换出来,提供给机体代谢所需。作为海洋植物渗透调节物质的主要成分,DMSP来源于植物体内的蛋氨酸。研究DMSP的生成变化规律,对进一步了解海洋气候和开发使用新的水产动物饲料添加剂有重要价值。  相似文献   
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