Award: OPP-1443483

Intellectual Merit Phytoplankton in the marine environment require nutrients like nitrogen and phosphorus to grow and reproduce. The trace metals iron, manganese, zinc, cadmium, cobalt, copper, and nickel are also nutrients for phytoplankton. In the Southern Ocean, iron is the scarcest of the nutrients required by phytoplankton and low iron availability limits phytoplankton growth here. For this project, feedbacks between trace metals and phytoplankton growth were assessed in a series of incubation experiments. Changes in the concentrations of trace metals were measured during the growth of natural Southern Ocean phytoplankton communities. In a subset of these experiments, iron was added to determine how relief from iron limitation would influence the cycling of trace metals during phytoplankton growth. Project results represent the first measurements of this suite of trace metals in Southern Ocean phytoplankton incubation experiments and provide new insights into trace metal bioavailability and cycling in this region. These results also show how phytoplankton growth can change the chemical form and associated availability of some of these trace metals to phytoplankton. Project results have been presented at national and international science conferences, and are in preparation for publication in the peer-reviewed literature. Broader Impacts Education, outreach and training have been integral to project activities. A high school science teacher participated in the project through the PolarTREC program. Project activities were incorporated into a series of inquiry-based lesson plans for high school science students through this collaboration, and aspects of shipboard life and project science were highlighted to the public via a series of blogs. These lesson plans, at-sea blogs, and related interviews and reports are publicly available on a dedicated webpage (https://www.polartrec.com/expeditions/southern-ocean-diatoms). Project activities have also been shared with middle school girls through a hands-on chemistry lab during the Oceanography Camp for Girls at the University of South Florida. Project data have also been made publicly available at the Biological and Chemical Oceanography Data Management Office (www.bco-dmo.org). Project activities provided training in field sampling, experimental design, and trace metal analyses for an undergraduate student from an underrepresented group, a research technician and a graduate student at the University of South Florida. Last Modified: 10/16/2019 Submitted by: Kristen N Buck