Research Hypothesis. The working hypothesis of this proposal is that a) phytoplankton growth can be controlled by the availability of the essential micronutrient iron b) symbiotic bacteria produce iron-binding compounds (siderophores) that can be utilized by the plankton to provide the iron needed for prolific growth, c) bacterially produced boron containing molecules may also contribute to control of phytoplankton growth d) a more complete understanding of this process could provide a means to predict where, when and under what conditions heavy growth of these organisms would occur.
