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Postdoctoral Research Associate - Biodiversity and Ecosystem Health

Oak Ridge National Laboratory
37830, Oak Ridge
Candidates may discuss with their recruiter at a later date
Closing date
Dec 1, 2023

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Earth and Space Science Informatics
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As a U.S. Department of Energy (DOE) Office of Science national laboratory, ORNL has an extraordinary 80-year history of solving the nation’s biggest problems. We have a dedicated and creative staff of over 6,000 people! Our vision for diversity, equity, inclusion, and accessibility (DEIA) is to cultivate an environment and practices that foster diversity in ideas and in the people across the organization, as well as to ensure ORNL is recognized as a workplace of choice. These elements are critical for enabling the execution of ORNL’s broader mission to accelerate scientific discoveries and their translation into energy, environment, and security solutions for the nation.

The Biodiversity and Ecosystem Health Group within the Environmental Sciences Division at Oak Ridge National Laboratory (ORNL) seeks a postdoctoral researcher with an understanding of aquatic biology and chemistry, with a specific focus on contaminant behavior and bioaccumulation in freshwater systems. The successful candidate will work collaboratively with an interdisciplinary team of environmental scientists at ORNL to understand the chemical and ecological factors controlling mercury methylation and bioaccumulation in contaminated aquatic systems and will develop experimental designs aimed at mitigating methylmercury bioaccumulation.

Mercury is one of the most pervasive and widespread contaminants worldwide but the relationship between environmental mercury concentrations, methylmercury production, and mercury bioaccumulation is poorly understood. Because methylmercury bioaccumulation in fish poses both a human health and ecological risk, there is a need to understand both the chemical and ecological drivers of mercury bioaccumulation in aquatic systems. In particular, the candidate will examine the effects of filter feeders on mercury dynamics in stream systems. As keystone species in freshwater ecosystems, freshwater bivalves can drastically affect water quality, habitat, and food web structures, and consequently their presence may also affect mercury bioaccumulation and trophic transfer. The results from this project will be useful in guiding future remediation efforts at Oak Ridge but will also provide a fundamental understanding of the processes governing mercury bioaccumulation in stream systems.

Major Duties/Responsibilities: 

  • Conduct microcosm experiments, such as bioaccumulation experiments of mercury into freshwater bivalves and periphyton
  • Conduct mesocosm experiments, such as empirically manipulating mercury bioavailability, concentration, etc. to decrease bioaccumulation of mercury into fish and investigate bioaccumulation of mercury through periphyton
  • Publish and present research results in journals and at conferences
  • Deliver ORNL’s mission by aligning behaviors, priorities, and interactions with our core values of Impact, Integrity, Teamwork, Safety, and Service. Promote diversity, equity, inclusion, and accessibility by fostering a respectful workplace – in how we treat one another, work together, and measure success.

Basic Qualifications:

  • A PhD in aquatic ecology, ecotoxicology, environmental science, or a related field completed within the last 5 years
  • Experience with experimental design
  • Excellent oral and written communication skills, able to present and publish their research
  • A proven publication records.
  • Ability to work independently and collaboratively as part of an interdisciplinary research team.

Preferred Qualifications:

  • Experience with analytical chemistry techniques to measure stable and/or radio isotopes of metals (e.g., mass spectroscopy, atomic absorption, or radio spectrometry) is preferred.
  • Experience working with mercury is strongly desired, but not required. 
  • Candidates should be well versed in experimental design, data analysis, modeling, and statistics. 
  • Experience coding in R or Python is a plus.
  • Experience conducting bioaccumulation or ecotoxicological experiments
  • Experience culturing and experimenting on freshwater mussels

Applicants cannot have received their Ph.D. more than five years prior to the date of application and must complete all degree requirements before starting their appointment. The appointment length will be for up to 24 months with the potential for extension. Initial appointments and extensions are subject to performance and the availability of funding.

Please submit three letters of reference when applying to this position. You can upload these directly to your application or have them sent to with the position title and number referenced in the subject line.

Instructions to upload documents to your candidate profile:

  • Login to your account via
  • View Profile
  • Under the My Documents section, select Add a Document

Benefits at ORNL:  

ORNL offers competitive pay and benefits programs to attract and retain talented people. The laboratory offers many employee benefits, including medical and retirement plans and flexible work hours, to help you and your family live happy and healthy. Employee amenities such as on-site fitness, banking, and cafeteria facilities are also provided for convenience.

Other benefits include: Prescription Drug Plan, Dental Plan, Vision Plan, 401(k) Retirement Plan, Life Insurance, Pet Insurance, Generous Vacation and Holidays, Parental Leave, Legal Insurance with Identity Theft Protection, Employee Assistance Plan, Flexible Spending Accounts, Health Savings Accounts, Wellness Programs, Educational Assistance, Relocation Assistance, and Employee Discounts.

If you have difficulty using the online application system or need an accommodation to apply due to a disability, please email:


This position will remain open for a minimum of 5 days after which it will close when a qualified candidate is identified and/or hired.

We accept Word (.doc, .docx), Adobe (unsecured .pdf), Rich Text Format (.rtf), and HTML (.htm, .html) up to 5MB in size. Resumes from third party vendors will not be accepted; these resumes will be deleted and the candidates submitted will not be considered for employment.

If you have trouble applying for a position, please email

ORNL is an equal opportunity employer. All qualified applicants, including individuals with disabilities and protected veterans, are encouraged to apply.  UT-Battelle is an E-Verify employer.


Oak Ridge National Laboratory is the largest science and energy national laboratory in the Department of Energy system. ORNL’s scientific programs focus on materials, neutron science, energy, high-performance computing, systems biology and national security. ORNL partners with the state of Tennessee, universities and industries to solve challenges in energy, advanced materials,manufacturing, security and physics. The laboratory's science and technology innovations are translated into applications for economic development and global security. The laboratory is home to several of the world’s top supercomputers and is a leading neutron science and nuclear energy research facility that includes the Spallation Neutron Source and High Flux Isotope Reactor. ORNL hosts a DOE Leadership Computing Facility—home of the Titan supercomputer; one of DOE’s nanoscience centers—the Center for Nanophase Materials Sciences; the BioEnergy Science Center—one of DOE’s Energy Research Centers; and the Consortium for Advanced Simulation of Light-Water Reactors, a DOE Innovation Hub.

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