Affiliate Research Assistant Professor
Joint Appointment Department of Earth Sciences
The overall aim of my research is to understand the generation, cycling, fate, and effects of contaminants in the environment. I approach such problems with rigorous and unique chemical analysis combined with field sampling, laboratory studies, geochemical modeling, and interdisciplinary approaches from the fields of hydrodynamics and microbiology.
I especially am drawn to studying the coastal zone due to the fascinating and complex processes that occur in this region of great societal importance. Human populations rely on the coastal zone for recreation, transportation, and fisheries resources. Yet the coast receives most of the contaminants carried by the terrestrial water cycle, and these contaminants are potential threats to coastal ecosystems.
Some of my research focuses include:
Chemistry of Trace Metals in Marine Sediments
I am very interested in the diagenetic process that controls the long term fate of metals in sediments. An amazing variety of chemical reactions, microbial processes and physical processes occur in the sediments and they all impact trace metal cycling. Understanding these processes is important for predicting the long term fate of contaminated sediments, assessing the importance of sediment metals in global biogeochemical budgets, and for applying trace metals profiles as paleo-tracers of past redox conditions.
I am working on high resolution pore water samples from Boston Harbor and Massachusetts Bay to determine the chemical pathways that lead to a release of trace-metals from fine-grained sediments. This work is in conjunction with William Martin of the Woods Hole Oceanographic Institution and Michael Bothner of USGS. I have also worked with Jennifer Morford at Franklin and Marshall College on sediment cores from the north-west Pacific Ocean margin to investigate the oceanic silver cycle.
The Role of Sediment Resuspension in Metal and Nutrient Release to Coastal Waters
Physical processes can play an important role in chemical cycles, and in the coastal zone, sediment resuspension can drive episodic releases of large quantities of material. I have used an erosion chamber to estimate the magnitude of both metal and nutrient release to coastal waters during sediment resuspension events. I am currently extending this work to investigate the fate of resuspended particles in the water column and to collect in-situ samples under a range of resuspension scenarios to gain a much better understanding of the role of sediment resuspension in transforming and transporting contaminants.
Nutrient Cycling in Acid Mine Drainage Biofilms
This project, in the research group of Jill Banfield at UC Berkeley, seeks to understand how nutrients and carbon are cycled in the microbiological communities that mediate the dissolution of pyrite. These chemoautolithotrophic communities are responsible for the generation of waters with pH values less than 1 that are highly enriched in trace metals such as zinc, copper and arsenic. I am especially interested in the transformations of nitrogen within the system and the fascinating interactions between geochemistry and the microbial community.
Ph.D Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program, 2005
B.E.(Hons) (Environmental Engineering) University of Western Australia 1995
B.Sc. (Hons) (Chemistry) University of Western Australia 1993
Courses I teach:
Introduction to Oceanography ESCI 501 (with Jamie Pringle)
Chemical Oceanography ESCI 752/852
Aqueous Geochemistry ESCI 747/847 (every second year in even numbered years)