Effects of ocean acidification on the interrelations of the trace metals cadmium, iron, and zinc; its implications for marine phytoplankton physiologiy and biological feedback mechanisms to climate change

微量金属的生物有效性影响海洋浮游植物群落的生长、光合作用效率、大量营养素的消耗以及物种组成。由于痕量金属形态对海水pH很敏感，因此持续的海洋酸化很可能会影响痕量金属的生物有效性，从而对未来海洋的痕量金属化学和浮游植物生产力产生重大影响。这里提出的项目结合了化学和生物学的方法来研究这些相互关系。化学部分集中于海水pH降低对南大洋水域中具有生物活性的痕量金属镉(Cd)、铁(Fe)和锌(Zn)的形态及其相互关系的影响。生物部分旨在调查其对初级生产力、物种组成和浮游植物元素组成的影响，并对碳循环和出口产生影响。通过研究痕量金属形态形成的生物反馈机制，这两个部分再次相互联系。该项目将与主办机构的一个项目密切相关，该项目旨在校准海水中PO4浓度的古镉替代物。Cd：PO4的关系是复杂的，被认为是受Cd利用生物群的影响，也受Fe和Zn的化学成分以及海水pH的影响。

Trace metal bioavailability influences growth, photosynthetic efficiency, macronutrient consumption, as well as species composition of the marine phytoplankton community. Since trace metal speciation is sensitive to seawater pH it is likely that ongoing ocean acidification will affect the bioavailability of trace metals and will therefore have major implications for the trace metal chemistry and phytoplankton productivity in the future ocean. The project proposed here combines a chemical and a biological approach to investigate these interrelationships. The chemical part concentrates on the effect of decreasing seawater pH on the speciation and interrelationship of the biologically-active trace metals cadmium (Cd), iron (Fe), and zinc (Zn) in Southern Ocean waters. The biological part aims to investigate the effect thereof on primary production, species composition, and phytoplankton elemental composition with implications for carbon cycling and export. Both parts are again interconnected by investigating biological feedback mechanisms on trace metal speciation. This project will be closely linked into a project at the host institution that aims to calibrate the cadmium paleo-proxy for PO4 concentrations in seawater. The Cd:PO4 relationship is complex and thought to be affected by Cd utilizing biota as well as by the chemistries of Fe and Zn, and seawater pH.