Our lab focuses on four main research areas related to the cycling of trace metals in the marine environment. We primarily study iron, copper, nickel, cobalt and zinc, but we are also interested in other metals and nutrients. We call these metals "trace" because they are generally present in very low concentrations in the ocean.
One of our main research areas is measuring the distributions of trace metals in different oceanic regions, ranging from coastal environments to the open ocean. We are also interested in understanding how these distributions are controlled by organic ligands, or the organic compounds associated with trace metals as they cycle through the ocean interior. Specifically, we aim to characterize these organic compounds and determine which organisms are actively producing organic molecules and why. And finally, we are working to understand the interaction between microorganisms and the uptake of trace metals in the environment in order to better understand their metal requirements.
Why trace metals?
Measuring their distributions in the marine environment
Our lab measures the distributions of trace metals such as iron, copper, cobalt and nickel in major ocean basins as well as coastal environments. This gives us a broad picture of how metals cycle in the ocean between the global oceans.
Characterizing organic compounds produced by microbes
Many of the organic compounds that bind trace metals in the ocean are produced actively by microorganisms in order to aid in their uptake, or in order to compete with other organisms for these vital nutrients. Siderophores are on of the most well-known examples of these compounds, and we seek to identify and quantify these compounds in seawater.
Understanding the organic compounds binding trace metals
We use a combination of analytical approaches in order to determine the extent to which trace metals are complexed by organic compounds in the marine environment. This can affect many aspects of the metal's cycling and reactivity.
Determining trace metal requirements for microorganisms
One of the most important aspects of the biogeochemical cycling of trace metals is their biological uptake. We aim to identify which chemical forms of trace metals are most bioavailable to different organisms, and examine how this effects competition for these nutrients among different microbes.