Associate Professor, Aquatic Biogeochemistry
Skidaway Institute of Oceanography, University of Georgia, Savannah, GA-31411, USA
1998 – 2002 Ph.D. Marine Biogeochemistry. Dept. Marine Sci. & Tech., Newcastle University joint Ph.D. with Plymouth Marine Laboratory.
Dissertation: Aspects of aquatic carbon monoxide photoproduction from coloured dissolved organic matter.
Advisors: Cliff S. Law, Guenther Uher and Robert Upstill-Goddard.
1995 – 1998 B.Sc. (Honors 2.1) Marine Biology. Dept. Marine Sci. & Tech., Newcastle University.
Dissertation: A global nitrogen cycle model: Balancing the present day cycle and predicting the effects of future anthropogenic perturbations upon tropospheric N2O. Advisor: Nicholas Owens.
Awarded Longbottom Prize for Most Outstanding Dissertation
1993 – 1995 A-Levels: Biology, Chemistry, Geography
05/2013-present: Associate Professor. Skidaway Institute of Oceanography, Marine Sciences Dept., University of Georgia, Savannah.
2013-present: Adjunct. Dept. Marine Sciences, Savannah State University (local HBCU).
2011-present: Adjunct. School of Earth and Atmospheric Sciences, Georgia Institute of Technology.
2011-present: Guest Scientist. Marine Geochemistry Group, ICBM, Oldenburg, Germany.
Associate Editor: Journal of Geophysical Research – Biogeosciences
Associate Editor: Estuarine and Coastal Shelf Science
About my work:
Professor Stubbins’ research group studies an integral component of the global carbon cycle, dissolved organic matter (DOM). All forms of life release DOM, which then provides nutrition to the microbes at the base of aquatic foodwebs. DOM cycling also redistributes carbon between land, ocean and atmospheric stores having direct impacts upon the carbon budget and climate of the planet. In addition to its importance as a metabolite and carbon pool, the complexity of DOM makes it incredibly interesting to study. DOM contains thousands, if not millions or trillions, of different molecules. Each derived from a living organism and subsequently altered in the environment. On mass these molecules provide a suite of tracers carrying the signatures of each molecule’s source and subsequent history in the environment. DOMeomics, the decoding of these signatures, is casting new light upon the biogeochemical cycles of the planet. Developments in the characterization of biomolecules are harnessing this information, allowing us to determine the isotopic, spectral, structural and molecular signatures of DOM. We study these signatures. As DOM is derived from all the life within an ecosystem these messages provide valuable information about the functioning of these ecosystems today and their likely response to local and global change. The information DOM provides is being used to determine the extent of feedbacks between climate, carbon storage and ecosystem function in diverse habitats including glaciers, permafrost, rivers, the salt marshes, and the open ocean. To find out more visit the project and publication links at www.skio.uga.edu/people/stubbins/.
Watershed dissolved organic matter transport: the pulses-shunt concept
Dissolved organic matter (DOM) is a key variable in global change and water quality research. Fluxes of DOM from land transfer limiting nutrients and pollutants across ecosystems. Within inland waters, DOM fuels secondary production and therefore is important to metabolism and CO2 evasion. DOM is also a main determinant of light penetration and “the browning” of inland waters in response to climate change, is important to ecological processes, and the management of drinking water. The current paradigm of the River Continuum Concept is based on the assumption that the majority of DOM reactions occur in small, 1st order streams, and that DOM reactivity decreases moving through the fluvial system from small headwater streams to large, higher order rivers. In this talk, an alternative conceptual model is presented: the Pulse Shunt Concept. A large amount of annual DOM export occurs during flood events. We hypothesize that the Riverine Continuum is overwhelmed by the “pulse” of water that cascades through a fluvial system as a river floods and reactive DOM is “shunted” further downstream, leading to greater reactive DOM export to coastal systems under flood conditions. The conceptual framework of the Pulse Shunt will be presented along with preliminary data from an ongoing project (www.skio.uga.edu/aboutus/people/stubbins/PSCRCC.pdf).