Micronutrient-based interactions in marine microbial communities

Oceanic microbes conduct a range of functions that are essential for the maintenance of life on earth, including the production of half of the oxygen in our atmosphere and the synthesis of organic carbon that supports fishery resources. The goals of this research program are to develop and implement novel tools, using microscopy techniques and measurement of proteins via mass spectrometry, to advance our understanding of what controls these important marine microbial processes. Marine microbes, just like humans, require micronutrients such as iron, zinc and vitamins for survival. In the oceans, these micronutrients are largely scarce and their concentrations vary by orders of magnitude over short time and spatial scales. There is competition for these limited resources, but there are also ways in which microbes cooperate to share, produce and consume micronutrients efficiently. This research program will focus on developing new tools to understand (1) when and where in the ocean the availability of these micronutrients shapes how much oxygen and carbon are produced in marine ecosystems, (2) how organisms cooperate or compete to make the most of these scarce resources and (3) how relationships between important groups of marine microbes are driven by demand for these micronutrients. This work requires extensive laboratory culturing and examination of marine microbes, including phytoplankton and bacteria, under defined conditions. Results from laboratory studies will be used to design and implement measurements reflecting micronutrient demand and supply in natural communities in the ocean, with study sites including the Antarctic Southern Ocean and the Scotian Shelf. The information gained through these studies will contribute novel insights into potential changes in marine productivity and how this may impact fisheries and other coastal resources, including the potential for harmful algal blooms. This laboratory will generate highly qualified personnel capable of developing and applying innovative protein diagnostics and microbial culturing approaches of use in environmental monitoring, biotechnology, and the health sciences.