| 摘要: |
| 于1994年4月对东海水域二甲基硫面酸（DMSP）浓度进行观测，结合对叶绿素和营养盐的监测结果，分析研究了DMSP分布及其调控因素。结果表明，DMSP浓度范围为0.17–5.66nmol/L，最高浓度出现于410站（125.0°E，29.3°N）。垂直分布浓度最大层出现在表层20m以内。DMSP分布与叶绿素-a的分布基本一致，与硝酸氮（NO3－N）的关系在NO3－N浓度小于0.5μmol/L时是正相关，而在NO3－N浓度高于10μmol/L时呈负相关。 |
| 关键词: 二甲基硫丙酸 叶绿素-a 硝酸氮 东海 |
| DOI： |
| 分类号: |
| 基金项目:国家杰出青年基金资助项目，39625008号;国家自然科学基金资助项目，39570143号 |
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| DISTRIBUTION OF DIMETHYLSULPHONIOPROPIONATE AND ITS CONTROLLING MECHANISM IN THE EAST CHINA SEA |
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JIAO Nian-zhi,LIU Cheng-zhang,CHEN Nian-hong
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Institute of Oceanology, The Chinese Academy of Sciences,Qingdao, 266071
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| Abstract: |
| Investigation into the distribution of dimethylsulphoniopropionate (DMSP) in the East China Sea was conducted in April 1994. DMSP was converted to dimethylsulfied by alkalization and then measured by the head-space GC FPD method. DMSP concentration ranged from 0.17–5.66 nmol/L, with the highest value occurring in the front area (around central of the sea, 125.0° E, 29.3°N) between the coastal water and the Kuroshio current. From this peak center, DMSP concentration decreased gradually towards the estuary of the Changjiang River and towards the Kuroshio oceanic waters. A significant correlation between DMSP and chlorophyll-a was recorded, indicating that DMSP concentration was associated with phytoplankton abundance. In vertical distribution, DMSP concentration peaked within the surface 20 m, then decreased sharply with increasing depth. DMSP concentration depth profiles were similar to those of chlorophyll-a.
Unlike the situation of previous laboratory experimental studies on the controlling mechanisms of DMS production from algal cells, no significant correlation was found between DMSP concentration and any physical parameters such as temperature and salinity. In contrast, DMSP concentration had interesting relationships with nutrient availability in the study area. When ambient concentrations of nitrate were lower than 0.5 μmol/L, DMSP was significantly correlated to nitrate, DMSP had a decrease trend with increasing nitrate when nitrate concentrations were higher than 1.0 μmol/L. Close correlations among DMSP, chlorophyll-a and nitrate in the former circumstance implies that nitrate might control the distribution of DMSP through regulating phytoplankton growth under nitrate-deficient conditions. In the later case, the inverse relationship between DMSP and nitrate was likely due to the substitution of DMSP by glycine betaine as an osmoregulatory substance when nitrate was relative abundant. Thus, a speculation of dual character of the effects of nitrate on natural DMSP abundance was proposed that nitrate, depending on its availability, can be either a promoter or an inhibitor of DMSP production. In the case of the East China Sea, the threshold of the nitrate concentration was around 0.5–1.0 μmol/L in the study period. |
| Key words: Dimethylsulphoniopropionate (DMSP), Chlorophyll-a, Nitrate, East China Sea |
