How do stream ecosystem functions respond to pollution and flow disturbances?

Funded MSc or PhD positions at Virginia Tech

Position Summary: Dr. Erin Hotchkiss (Department of Biological Sciences, Virginia Tech) is seeking applicants for 1-2 M.Sc. or Ph.D. graduate student positions with a target start date in August 2023. The new student(s) will have the opportunity to develop thesis or dissertation research linking water quality and stream functions (e.g., photosynthesis, respiration, nutrient cycling) to pollution and flow disturbances. The student(s) will contribute to collaborative research projects testing the ecological consequences of land use, pollution, and other environmental changes in streams of the southern Appalachian region of the United States. Graduate students will have freedom to develop their own research questions while also contributing to broader project goals when they are funded by a collaborative research grant. Additional information about specific projects will be added below as funding awards are finalized.

  1. Ecological consequences of freshwater salinization in mining-impacted streams

The MSc or PhD student will be co-advised by Dr. Erin Hotchkiss (Biological Sciences, Virginia Tech) and Dr. Daniel McLaughlin (Forest Resources and Environmental Conservation, Virginia Tech); the student's degree program will be through the Hotchkiss Lab in Virginia Tech's Department of Biological Sciences.

Mining and other human activities are making freshwater ecosystems salty (i.e., freshwater salinization). How the ecology of freshwater ecosystems is changing with salinization is still largely unknown. The primary responsibilities of the graduate student working with our project team will be to develop and answer research questions related to (1) testing how water quality changes with stream flow and (2) characterizing patterns of algal production and whole-stream metabolism in Appalachian streams across a gradient of mining impacts. We do not expect applicants to have the skills and knowledge to conduct this research when they apply; learning how to do this research is part of the graduate student training process. The graduate student will work collaboratively with other members of the project team (graduate students, research technicians, undergraduate researchers, and professors) to conduct fieldwork for their own research as well as research characterizing (1) microbial and invertebrate production and (2) the transfer of energy across food web trophic levels. The overall goal of our project is to assess mining-induced salinity effects on carbon cycling and food web energetics in headwater streams, which we will accomplish through measurements of water quality and hydrology, food web carbon production and transfer, and ecosystem metabolism.

The student will receive at least two academic years (fall and spring semesters) and three summers of salary support as a Graduate Research Assistant on our NSF-funded collaborative project led by Dr. Sally Entrekin (Entomology, Virginia Tech). Additional years of funding, if needed, will be supported by student fellowships, teaching assistantships, and/or other lab-funded projects. Drs. Hotchkiss and McLaughlin are collaborators on the project led by Dr. Entrekin along with Dr. Stephen Schoenholtz (Forest Resources and Environmental Conservation, Virginia Tech), Dr. Carl Zipper (Emeritus Professor, Virginia Tech), and Dr. Teresa Brown (Geology, UVA-Wise).

The student funded on this project will need to be available to start their degree program in August 2023. Please see www.hotchkisslab.com/opportunities for more information about preferred applicant qualifications, the expectations and benefits associated with joining our research group, and how to apply. We anticipate scheduling the first round of remote interviews with top potential applicants (who emailed a letter of interest and CV) by mid-October 2022.

2. Stream metabolic responses to changes in land use and flow disturbances

The MSc or PhD student will be advised by Dr. Erin Hotchkiss (Biological Sciences, Virginia Tech, www.hotchkisslab.com).

Human activities on the landscape alter nutrient and carbon inputs to streams; microbial processes within streams can metabolize carbon and nutrient inputs and thus alter water quality. Much of our understanding of how stream ecosystems respond to human activities is from measurements focused on aerobic (with oxygen) microbial processes, but sediment pollution and the accumulation of sediments and biofilms on the bottom of streams can create anaerobic (without oxygen) conditions that set the stage for different, and often unquantified, microbial processes that also cycle carbon and nutrients. The primary responsibilities of the graduate student working with our project team will be to develop research questions related to how stream primary production and carbon metabolism change with land use, sediment and nutrient pollution, and dissolved oxygen concentrations using a combination of bottle assay, artificial stream (i.e., flume), and whole-ecosystem measurements in Appalachian streams of Virginia and Tennessee. The graduate student will work collaboratively with other members of the project team (graduate students, research technicians, postdocs, state/federal scientists, and professors) to conduct fieldwork for their own research as well as research that supports other project objectives. The overall goal of this project is to characterize stream, river network, and watershed functional responses to land use change (e.g., urban development and deforestation) and hydrologic intensification.

The student will receive up to three academic years (fall and spring semesters) and three summers of salary support as a Graduate Research Assistant on a federally-funded collaborative research project that is still in the process of finalizing its funding award. Additional years of funding, if needed, will be supported by student fellowships, teaching assistantships, and/or other lab-funded projects.

There may be some flexibility in the start date for this position, but we are currently planning for an August 2023 start. Please see www.hotchkisslab.com/opportunities for more information about preferred applicant qualifications, the expectations and benefits associated with joining our research group, and how to apply.