Lake Bonney, Dry Valleys Antarctica

People of the Wells Laboratories

EcoHAB 6 Cruise, fall 2006

Principal Investigator


Mark L. Wells
A number of trace metals in seawater are essential micronutrients for phytoplankton and heterotrophic bacteria (e.g., Fe, Zn, Co, Cu, Cd, Mn). If the availability of one or more of these metals is too high they exert toxic effects while too little can limit productivity. Because phytoplankton species differ in their metal requirements and tolerances, changes in metal concentration or chemical speciation should have a strong influence on the composition of plankton assemblages as well as the net carbon transport from surface to deep waters.  My research group studies the chemistry of bioactive metals in seawater and lake waters, their effects on phytoplankton and bacteria and, in turn, how these factors may alter ocean optics and the remote sensing of phytoplankton distributions by satellites.


Graduate Students


Lisa Pickell
I am interested in studying the biogeochemical cycling of iron in the ocean and how the speciation of iron influences phytoplankton growth.  My research will involve comparison field studies between natural communities of coastal and oceanic phytoplankton, as well as laboratory grown monocultures.  The aim of my thesis project is to contribute a better understanding of iron availability to different phytoplankton and how this may impact carbon cycling on a global level.
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Eric Roy
My current research focuses on iron redox cycling in natural surface waters, with emphasis on kinetic control of metal speciation. The work addresses the larger question: "How does metal speciation affect bioavailablity to phytoplankton?" In the near future, my work will be shifting toward using nanotechnology to develop better chemical sensors for use in marine environments.

Research Specialists

        Margaret (Peggy) Hughes
My current work with Pseudo-nitzschia , a domoic acid producing diatom responsible for Sea Lion deaths along the central California coast, has focused on investigating environmental triggers, both toxic and limiting factors, which affect toxic algal blooms in  Monterey Bay and Central California.  I isolate Pseudo-nitzschia clones from Monterey Bay for studies which focus on physiological and environmental stresses shown to regulate cell toxicity.
        Kathy Hardy
My background is in the study of microbial processes in marine environments. I currently am the senior laboratory manager with responsibilities to oversee most aspects of the research in the Wells group. My research interests have evolved to the study of trace metal analysis and the use of tracers to measure the phytoplankton uptake of, and influence due to, nutrient trace metals in nearshore environments and offshore High Nitrate, Low Chlorophyll waters. A summary of my experience on a recent cruise to the subarctic Pacific Ocean can be found here.

Sheri Floge
I am currently investigating how marine colloids influence the optical characteristics of seawater with the ultimate goal of improving the capability to forecast temporal and spatial patterns of colored dissolved organic matter (CDOM) in coastal waters.  Specifically, I am characterizing variations in colloid size distribution and associated optical characteristics (absorbance, fluorescence and scattering) related to in situ phytoplankton productivity dynamics and degradation via photochemical and microbial processes.


Adjunct Research Scientists of the Wells Laboratory


Jennifer Boehme
My scientific interests are currently focused on biological, chemical and physical processes that affect carbon cycling in the marine environment, in the form of dissolved organic matter.  In my research I also am interested in monitoring and cycling of organic pollutants in aquatic environments, fluorescence sensor development, and laser-induced fluorescence techniques. My current research uses three dimensional fluorescence techniques and multivariate statistics to examine the regional and process-driven variations in DOM fluorescence.  We have been investigating the influence of colloids and their size distribution on optical properties of marine organic matter. I am currently involved in work with the Smithsonian Environmental Research Center to establish chemical and optical tracer methods capable of monitoring ballast water exchange in commercial vessels.  The ultimate goal is to prevent invasion of exotic species via international shipping activity.