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    image 01
    The Morel Research Group experience many amazing sunsets while at sea.
    The Morel Research Group experience many amazing sunsets while at sea.
     
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    image 02
    On view is a Diatom, one of the most common types of phytoplankton, under the microscope in the Morel Laboratory.
    On view is a Diatom, one of the most common types of phytoplankton, under the microscope in the Morel Laboratory.
     
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    image 03
    A dock awaits to take students on a Freshman Seminar field trip in the Everglades. Students collect water samples to evaluate quality in the context of geology, chemistry, and biology of the ecosystem.
    A dock awaits to take students on a Freshman Seminar field trip in the Everglades.
     
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    Image 04
    Then graduate student Jenna Losh *13 preparing a rosette of seawater sampling bottles to be dropped into the ocean depths. Losh is on board a research vessel in order to collect deep water samples for analysis.
    Then graduate student Jenna Losh *13 preparing a rosette of seawater sampling bottles to be dropped into the ocean depths.
     
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    Image 05
    Postdoctoral Research Associate Dr. Ja-Myung Kim working in the Morel laboratory at Guyot Hall.
    Postdoctoral Research Associate Dr. Ja-Myung Kim
     
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    Image 06
    Postdoctoral Research Associate Dr. Sven Kranz on board a research vessel at sea.
    Postdoctoral Research Associate Dr. Sven Kranz
     
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    Image 07
    Postdoctoral Research Associate Dr. Jeffra Schaefer, Geosciences Lecturer Dr. Anne Morel-Kraepiel and Professor François Morel collaborating in a classroom at Guyot Hall.
    Dr. Jeffra Schaefer, Geosciences Lecturer Dr. Anne Morel-Kraepiel and Professor François Morel.
     
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    Image 08
    Postdoctoral Research Associate Dr. Yan Xu dressed to work in one of the many "clean" laboratories at Guyot Hall.
    Postdoctoral Research Associate Dr. Yan Xu
     
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    Image 10
    An interesting-shaped Diatom, one of the most common types of phytoplankton, under the microscope in the Morel Laboratory.
    An interesting-shaped Diatom
     
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    Image 11
    Postdoctoral Research Associate Dr. Xinning Zhang presenting her research at a American Society of Microbiology meeting in New Orleans.
    Postdoctoral Research Associate Dr. Xinning Zhang
     
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    Image 12
    Postdoctoral Research Associate Dr. Sven Kranz among the penguins on a research field trip to Antarctica.
    Postdoctoral Research Associate Dr. Sven Kranz
     
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    Image 13
    A floating glacier melt on a research field trip in Antarctica.
    Floating glacier melt in Antarctica
     
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    Image 14
    Students travel by air boat to collect samples in the Everglades for water quality evaluations.
    Students travel by air boat in the Everglades
     
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    Image 15
    Students collecting water and soil samples in the Everglades for Freshmen Seminar: Global Change and the Impact of Human Activities on the Biosphere.
    Students collecting water and soil samples in the Everglades
     
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    Image 16
    Postdoctoral Research Associate Dr. Jodi Young and Sven Kranz collecting water samples in Antarctica.
    Drs. Jodi Young and Sven Kranz
     

Research

Environmental Chemistry and Microbiology of Trace Metals

Some trace metals such as iron and zinc are essential for life and their low concentrations sometimes limit the growth of organisms. Other metals such as mercury and cadmium are pollutants that sometimes reach toxic concentrations in the environment. Our research deals with the chemical and biological mechanisms that determine the transformations, the biological uptake, the physiological and ecological effects, and the global cycling of trace metals in the environment. By catalyzing biological transformations as cofactors of key enzymes, trace metals also play a critical role in the global cycles of the major elements of living matter, carbon, nitrogen and phosphorus (C, N and P). One of our research themes (sometimes called “environmental bioinorganic chemistry”) is the elucidation, at both the molecular and the global level, of the linkages between the cycles of trace metals and those of C, N and P.

We approach our work with a mix of laboratory and field experiments using a variety of chemical, microbiological, and genetic tools, as appropriate.  Our work is also informed by theoretical considerations from a number of disciplines ranging from bioinorganic chemistry to geology and ecology. 

Research Themes:

Ocean Acidification
Our aim is to understand the physiological response of marine phytoplankton to the direct and indirect chemical and physiological changes caused by ocean acidification. 
Inorganic Carbon Acquisition by Phytoplankton Various species of microalgae are known to compensate for low CO2 availability by operating different types of carbon-concentrating mechanism (CCM). Metal Complexing Agents
In natural waters and in culture media, the bioavailability of trace metals to microorganisms depends on their binding to a variety of weak and strong complexing agents.
Metal Uptake by Phytoplankton
In the surface oceans, essential trace metals such as iron (Fe) and zinc (Zn) are present at extremely low concentrations, in the nanomolar to picomolar range. The bulk of these metals is bound in highly stable organic complexes.
The Biological Role of Cadmium
Cadmium, (Cd), an element which has been thought to be only toxic to organisms, behaves exactly like a nutrient in the sea: it is depleted to very low concentrations as result of biological uptake at the surface and remineralized at depth.
The Role of Metals in Nitrogen Cycling in Soils
We are interested in understanding how metal availability affects nitrogen fixation in terrestrial ecosystems. 
Mercury Cycling and Methylation
Mercury is one of the most toxic trace elements. Because of the volatility of elemental mercury (Hg0) and the high reactivity of the mercuric ion (Hg2+), it is also one of the most elusive.
An Archive of Past Research
Over the years, the research activities in the Morel group have been focused principally on the related research themes of the chemical speciation of trace metals in natural waters, the interactions between trace metals and aquatic microorganisms, and the role of trace metals in controlling the biogeochemical cycles of bioactive elements.
 

Department of Geosciences Logo

The Trace Metal Group is a research lab within the Department of Geosciences at Princeton University.  The Geosciences Department, together with its affiliated inter-departmental programs and institutes, serves as the central focus for the Earth, atmospheric, oceanographic, and environmental sciences at Princeton.