Iron is an essential micronutrient for marine phytoplankton, which plays a key role in the global carbon cycle and marine ecosystems, and there is a need to better understand the sources and sinks of this essential micronutrient in the oceans. Iron isotopes are a recently developed tracer of iron biogeochemical cycling, and new iron isotope results indicate that iron-binding ligands may play a critical role in the isotopic fractionation of dissolved iron. At present, however, the quantitative importance of iron dissolution or biological iron uptake in the isotopic fractionation of dissolved iron in the oceans is not well-known. In this study, researchers from the University of South Carolina and the Bermuda Institute of Ocean Sciences will collect and analyze samples from the Bermuda Atlantic Time-series Station (BATS) in order to; 1) measure the rate and isotope fractionation of iron dissolution from natural aerosols and oxic sediments in the presence of natural iron-binding ligands, and; 2) examine how phytoplankton fractionate iron isotopes during biological uptake. Results from this study will advance the development of iron isotopes as a tool for tracing iron biogeochemical cycling in the oceans.
Broader Impacts: The project will provide scientific training and development to undergraduate, graduate, and postdoctoral students. Results of the study will be used to raise public awareness of biogeochemical science via a webpage, outreach activities, and public tours at the Bermuda Institute of Ocean Sciences.
