Dynamics of trace bioelements and their effects on the ecosystem in the marine environment

1.建立了螯合吸附柱萃取-电感耦合等离子体质谱法测定海水中痕量金属元素的分析方法。观测了北太平洋Fe、Co、Ni、Cu、Zn、Cd、Pb的分布。海水中酸溶态铁的含量高于溶解态铁，表明海水中以不稳定颗粒态铁为主。虽然夏季表层水中溶解态Fe和Zn在亚北极北太平洋是亏损的，但在副热带北太平洋是丰富的. 1999年夏季亚北极北太平洋浮游植物光合能力存在东西梯度，这种差异可能是由海水中Fe含量引起的。通过色素标记，发现植物区系发生了显著的变化.我们参加了一次中尺度的铁富集在西亚北极北太平洋（SEEDS 2001）。藻类光系统的光化学量子效率表明浮游植物群落受到铁胁迫，富铁改善了浮游植物的生理状况。有一些5纳米的不稳定颗粒铁在该领域。它由风尘提供，但浮游植物并不容易获得。溶解态Co、Ni、Cu、Zn和Cd的减少发生在浮游植物水华期间.建立了一种灵敏的螯合配体交换吸附阴极溶出伏安分析方法，并对真核浮游植物铁配体进行了检测.我们建立了一种从铁胁迫下的浮游植物中分离纯化RNA的技术。研究了铁胁迫下浮游植物膜蛋白组成的变化.浮游植物的培养实验表明，浮游植物的生长受共存有机配体的种类和浓度的控制。

1. An analytical method for the determination of trace metals in seawater has been developed on the basis of chelating adsorbent column extraction-ICP mass spectrometry. The distributions of Fe, Co, Ni, Cu, Zn, Cd, and Pb in the North Pacific have been observed. The concentration of acid-dissolvable Fe is higher than that of dissolved Fe, showing the dominance, of labile particulate Fe in seawater. Although dissolved Fe and Zn in summer surface water are depleted in the subarctic North Pacific, they are abundant in the subtropical North Pacific.2. We have found that there was an east-west gradient in the photosynthetic, competence of phytoplankton in the subarctic North Pacific in the summer of 1999 and that the difference was probably caused by Fe levels in seawater. A dramatic floristic shift was found by pigment signatures.3. We have participated a mesoscale Fe enrichment in the western subarctic North Pacific (SEEDS2001). The photochemical quantum efficiency of algal photosystem suggested that the phytoplankton community was suffered from Fe stress and the Fe enrichment improved the physiological condition. There was some 5 nM of labile particulate Fe in the field. It had been supplied by aeolian dust, but it was not readily available for phytoplankton. The decrease in dissolved Co, Ni, Cu, Zn, and Cd occurred during the phytoplankton bloom.4. A sensitive analytical method has been developed using chelating ligand exchange-adsorptive cathodic stripping voltammetry, and Fe ligands derived from eukaryotic phytoplankton have been detected.5. We have developed a technique to separate and purify RNA from phytoplankton under Fe stress. The composition change in membrane proteins of Fe-stressed phytoplankton has been observed.6. Incubation experiments of phytoplankton have shown that the growth of phytoplankton is controlled by the species and concentrations of co-existing organic ligands.