Metal Speciation and Cyanolbacterial Ecology in the Sargasso Sea

化学海洋学家和海洋微生物学家早就知道，海水中的微量金属对海洋浮游植物和细菌的影响，取决于微量金属存在的浓度、实际化学形式或种类。同样，我们也知道，这些生物能够分泌络合剂，改变痕量金属的形态，使它们或多或少可被吸收，或多或少具有毒性。众所周知，中央海洋环流地表水中微量金属的极低浓度可能会限制生物生产，正如最近对铁的证明那样。在这个项目中，来自伍兹霍尔海洋研究所和麻省理工学院的研究人员将把这些现象作为一条双向街来研究：水柱微量金属影响海洋微生物群落和海洋微生物群落影响水柱微量金属化学。这些研究将包括实地（马尾藻海）和实验室研究两种蓝藻及其与水柱中钴、铁和铜的生物地球化学关系。主要的重点将放在钴上，因为它作为一种微量营养素很重要，而且人们对它在海洋环境中的化学形态了解甚少。

ABSTRACT OCE-9618729 / OCE-9701681 Chemical oceanographers and marine microbiologists have known for some time now that trace metals in seawater affect ocean phytoplankton and bacteria differently depending upon the concentrations actual chemical forms, or species, in which the trace metal is present. Similarly, it is also known that such organisms are capable of secreting complexating agents that change trace metal speciation, making them more or less assimilable and more or less toxic. It is known that the very low concentrations at which trace metals are present in surface waters of the central ocean gyres may limit biological production, as has been demonstrated recently for iron. In this project, investigators from the Woods Hole Oceanographic Institution and the Massachusetts Institute of Technology will study these phenomena as a two-way street: water column trace metals affecting oceanic microbial communities and oceanic microbial communities affecting the water column trace metal chemistry. The studies will involve field (Sargasso Sea) and laboratory studies with two species of cyanobacteria and their biogeochemical relationship with cobalt, iron, and copper in the water column. The primary emphasis will be on cobalt because of its importance as a micronutrient and because so little is know about its chemical speciation in the oceanic environment.