ECIMMEE Project: Quantifying the impact of rising temperatures on microbial micronutrient demand
Marine primary productivity, conducted largely by phytoplankton, forms the base of marine food webs and is a major factor in determining the relationship between the ocean and atmospheric CO2 concentrations. Temperature, nutrient and light availability are key drivers of phytoplankton growth. Questions regarding how these variables interactively influence photosynthetic microbes remain and are a major source of uncertainty in efforts to predict future changes in marine primary productivity. Along with macronutrients like nitrogen, phosphorus, and silica, phytoplankton also require a suite of micronutrients including iron, zinc, and cobalamin (vitamin B12). In vast regions of the surface ocean, phytoplankton growth is limited by the availability of these micronutrients. Given the extent of this limitation as well as the fact that micronutrient availability is projected to change regionally in the coming decades, understanding the ramifications of simultaneous alterations in micronutrient availability and temperature for phytoplankton growth is imperative. Available evidence suggests that micronutrient demand may decrease in the face of elevated temperatures; however predictions from cellular models are not always reflected in observations and so major uncertainties remain. This research program aims to identify, quantify and contextualize interactions between micronutrient demand and temperature in marine microbes. This research program will use a combination of quantitative field, laboratory and metabolic modeling approaches to (1) enhance our understanding of the role of micronutrients in a changing ocean, (2) offer empirical data for evaluating fundamental questions about the relationships between matter and energy balance in microbial ecology, and (3) provide clarity to global modeling efforts seeking to predict changes to primary productivity in the future ocean.
Erin Bertrand is an Assistant Professor and NSERC Tier II Canada Research Chair in Marine Microbial Proteomics in the Biology Department at Dalhousie University, Halifax, Nova Scotia. Erin received a B.S. with honors in Chemistry and Environmental Studies from Bates College in 2005. She went on to complete her Ph.D. in Chemical Oceanography in the MIT/WHOI Joint Program, where she was awarded the Fye Award for Excellence in Chemical Oceanography research, 2010–2015. From 2012 to 2015, Erin was a U.S. National Science Foundation Office of Polar Programs Postdoctoral Fellow at the J. Craig Venter Institute and Scripps Institution of Oceanography. Her research aims are focused on understanding how microbes influence ocean biogeochemistry. She is particularly interested in the molecular basis of microbial micronutritional requirements and what the consequences of those requirements are for global carbon, nitrogen and sulfur cycling. Her group employs a range of quantitative mass spectrometry–based techniques, paired with field and laboratory experiments, to ask these questions.