Metal Speciation and Cyanolbacterial Ecology in the Sargasso Sea

摘要OCE-9618729/OCE-9701681化学海洋学家和海洋微生物学家已经知道，海水中的痕量金属对海洋浮游植物和细菌的影响不同，这取决于痕量金属存在的实际化学形态或物种的浓度。同样，人们也知道，这类生物能够分泌络合剂，改变痕量金属的形态，使它们或多或少被同化，或多或少具有毒性。众所周知，中央大洋环流表层水中微量金属的浓度很低，可能会限制生物生产，最近铁的情况就证明了这一点。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双向通道进行研究：影响海洋微生物群落的水柱痕量金属和影响水柱痕量金属化学的海洋微生物群落。这些研究将涉及现场(马尾藻海)和实验室对两种蓝藻的研究，以及它们与水柱中的钴、铁和铜的生物地球化学关系。主要重点将放在钴上，因为它作为一种微量营养素很重要，而且人们对其在海洋环境中的化学形态知之甚少。

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.