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

微量金属的生物利用度影响海洋浮游植物群落的生长、光合效率、宏量营养素消耗以及物种组成。由于微量金属的形态对海水pH值很敏感，因此正在进行的海洋酸化可能会影响微量金属的生物利用度，因此将对未来海洋中微量金属化学和浮游植物的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。化学部分主要研究了海水pH降低对南大洋中具有生物活性的微量金属镉（Cd）、铁（Fe）和锌（Zn）的形态和相互关系的影响。生物部分旨在研究其对初级生产、物种组成和浮游植物元素组成的影响，以及对碳循环和出口的影响。通过研究微量金属物种形成的生物反馈机制，这两个部分再次相互联系。该项目将与东道国机构的一个项目密切相关，该项目旨在校准海水中PO4浓度的镉古代用物。Cd:PO4的关系是复杂的，被认为受Cd利用生物群、铁和锌的化学性质以及海水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.