Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock ( Lock A locked padlock ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

  • Environmental Topics
  • Laws & Regulations
  • Report a Violation
  • About EPA
Risk Assessment
Contact Us

Reference Condition Research in NARS

On this page:

  • Overview
The National Aquatic Resource Surveys (NARS) are a critical source of data regarding the health of aquatic ecosystems in the U.S. Interpreting these data require that scientists be able to estimate how each ecosystem would function in the absence of anthropogenic stressors. For most indicators, these expectations are set using the concept of reference condition. This presentation discusses some of the difficulties inherent in operationalizing this concept, and the research under way to improve the science behind it.

Impact/Purpose

The National Aquatic Resources Surveys a reference site approach to setting expectations for many indicators. This talk explores some of the difficulties inherent in this approach and describes the research currently underway to improve the science of reference condition.

Citation

Stoddard, J. Reference Condition Research in NARS. NARS National Symposiium, NA, Virtual, April 05 - 07, 2022.
  • Risk Assessment Home
  • About Risk Assessment
  • Risk Recent Additions
  • Human Health Risk Assessment
  • Ecological Risk Assessment
  • Risk Advanced Search
    • Risk Publications
  • Risk Assessment Guidance
  • Risk Tools and Databases
  • Superfund Risk Assessment
  • Where you live
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 14, 2022
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshots
  • Grants
  • No FEAR Act Data
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Open Government
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions

Follow.