Dr. Hall has finished; Here is his contact information:
Currently a post-doc in Dr. Tom Battin’s Laboratory
Department of Freshwater Ecology
University of Vienna
Althanstr. 14
A-1090 Vienna, Austria
Andre has returned to Brazil:
André Megali Amado (Ph.D).
Professor Adjunto
Departamento de Oceanografia e Limnologia
Universidade Federal do Rio Grande do Norte
Via Costeira, S/N; Praia de Mãe Luiza
CEP(Zip): 59014-100; Natal - RN - Brasil
e-mail: amado@ufrnet.br
I am interested in the constraints imposed on microorganisms by physical and chemical characteristics of their environments. Specifically, I am interested in questions related to microbial metabolism. I am currently conducting experiments to quantify respiration rates in sediment core samples from Lake Superior. I am also collaborating with Amy Hansen, a graduate student in Civil Engineering, to determine whether aqueous heavy metals accumulate in primary producers like aquatic plants and epiphytic microbes, and whether accumulation is controlled by flow rate.
Shallow lakes exist in either a phytoplankton-dominated, turbid-water state or a macrophyte-dominated, clear-water state. Since the source of carbon is primarily plants (macrophytes) in one state and algae (phytoplankton) in another, the quality of carbon could differ greatly between states thus affecting everything from the lake's food web to its ability to sequester carbon dioxide. I am observing the effects of food web manipulations on the persistence of macrophytes and algae, and its subsequent effects on the carbon cycle of wetlands in the prairie pothole region of Minnesota.
I started my education convinced that I would end up in chemical sales. I got a degree in chemistry and a degree in communications from the University if Minnesota hoping to be the best saleswoman/scientist I could be. The problem was, I wound up feeling that there were much bigger problems facing our water resources than how to best soften the water in cooling towers around the Twin Cities. Through my research experiences in the Chemistry, Public Health, and Conservation Biology departments I became fascinated with the potential to describe aqueous biological systems as they are perturbed by natural and human induced actions. Questions like how can we model these changes in water systems to predict or in some cases even maximize beneficial biological processes, are often so difficult, but very important to ask. By studying how changing environmental conditions, like nutrient limitation and surplus, are impacting the metabolism of bacteria, I hope to begin to address how simple organisms may be responding to non-equilibrium dynamics in their environment.
I am broadly interested in biogeochemical cycling in freshwater systems. Specifically, my research focuses on evaluating the effects of sediment resuspension on the interaction between autotrophic and heterotrophic production in clear-water and turbid-water shallow lakes. During sediment resuspension events, nutrients bound within the sediments are transferred to the water column where they may be taken up by heterotrophs and/or autotrophs. The interaction between these groups may be affected by the degree of sediment resuspension, which varies between clear- and turbid-water lakes. Additionally, I would like to assess how net ecosystem production is indirectly affected by sediment resuspension, and how this relationship influences the potential of an ecosystem to sequester carbon.
Ted is now a post-doc at USGS in Boulder, CO.
U.S. Geological Survey, 3215 Marine Street, Suite E-127, Boulder, CO 80303
email: estets@usgs.gov
I am interested in how microbial physiology interacts with community- and ecosystem-level processes in nutrient cycling. My current question is how phosphorus requirements affect the diversity and stoichiometry of heterotrophic bacteria in lakes.
email: godwi018@umn.edu
The objective of my graduate work is to determine how the photochemical and biological processing of anaerobic dissolved organic matter (anDOM) differs from DOM produced in the presence of oxygen (oxDOM). Because anDOM is more reduced than oxDOM and oxygen is a strong oxidant, I hypothesize that anDOM differs from oxDOM in that it is more readily consumed biologically and photochemically. Lakes are important systems for processing dissolved organic carbon and have strong effects on the global carbon cycle. Therefore, understanding how photochemical and bacterial processes are affected by anDOM has important implications not only for aquatic food webs, but also for the global carbon cycle.