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                                          Erin R. Hotchkiss

Current Research Projects

 

 

Patterns and drivers of carbon cycling in streams & rivers

(2007 – Present)

Global carbon and oxygen cycles are directly linked to the productivity and respiration of biological communities.  Using the natural abundance of δ18O-O2 coupled with carbon isotope tracers, I hope to address the potential underestimation of daytime respiration rates in aquatic systems.  I am also interested in comparing diel cycles in community respiration with the potential drivers of these cycles: changes in temperature as well as DOC availability fueled by in-stream primary production and/or UV-breakdown or organic matter.  Assistance with this project: R.O. Hall (UWYO), B. Roberts (ORNL), S. Casebolt (Iowa), T. Lehnertz (UWYO), E. Anoszko (Gustavus Adolpus) and R. Crosby.  [Photos]

 

Sources, uptake and fate of dissolved organic carbon in aquatic ecosystems

(2009 – Present)

We are interested in large-scale patterns of dissolved organic carbon (DOC) uptake and fate, as well as the mechanisms (sources and processes) that increase or decrease DOC availability in freshwater ecosystems.  Collaborators: A. Ulseth (UWYO), B. Barnes (USGS), W. Wollheim (UNH) and J. Kominoski (UBC).

 

Controls on nitrate uptake in a semi-arid stream

(2007 – Present)

This project will focus on the roles of hydrology and geomorphology in nitrogen uptake along three different reaches of Red Canyon Creek, Wyoming.  I will also compare nitrate uptake with rates of community respiration and whole stream metabolism over 24-hour cycles.  Collaborators: L.K. Lautz, K.A. Hubbard and M.J. Mitchell (SUNY-ESF). [Photos]

 

Invasive snails and stream ecosystem processes

(2006 – Present)

My M.S. research compared calcification rates of invasive snails with stream CO2 fluxes.  Ongoing research seeks to understand the difference in basal metabolic rates, assimilation efficiencies, and contributions to nutrient cycling by native (Pyrgulopsis robusta) and invasive (Potamopyrgus antipodarum and Melanoides tuberculata) freshwater snails in Grand Teton National Park, Wyoming.  We will compare these rates of snail carbon and nutrient cycling to ecosystem-level processes.  I will also continue to monitor the effect of Melanoides tuberculata on native macroinvertebrates and native fish populations in Kelly Warm Springs, as well as the role of Melanoides as an intermediate host for parasites in Wyoming.  Assistance from and collaboration with: S. O’Ney (NPS), T. Tibbets, A. Krist, B. Hansen, T. Neikum, R. Crosby (UWYO), S. Casebolt (Iowa) and E. Anoszko (Gustavus Adolpus).

Photo credit: Melanoides tuberculata by S. Casebolt. [Photos]