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

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Emergency Response
    • Environmental Information by Location
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History

Breadcrumb

  1. Home
  2. National Aquatic Resource Surveys
  3. Background
  4. Indicators

Indicators: Ecological Fish Tissue Contaminants

What are ecological fish tissue contaminants?

Ecological fish tissue contaminants are chemicals, including metals and organic compounds, that have accumulated within the bodies of fish by way of absorption from the water or ingestion of contaminated food items. Contaminants tend to remain in tissues and may become more concentrated in muscles, skin and other organs over time. This is known as biomagnification. Because contaminants may accumulate in different ways in different organism, whole fish are analyzed for the presence of contaminants.

Photo credit: University of Houston Clear Lake

Why are ecological fish tissue contaminants important?

It is important to measure contaminants in tissue of prey fish because this provides us with information on the risks that contaminants can pose for organisms that eat them. Contaminant levels in prey species can further accumulate in predators such as birds, mammals and other fish, potentially leading to adverse impacts that reduce the health of these populations. Health effects may include decreased reproductive success and reduced growth and development. 

What can ecological fish tissue contaminants tell us about the condition of water?

The ecological fish tissue contamination index indicates whether predatory fish, birds or mammals could experience adverse, nonlethal effects such as stunted growth or reduced reproductive success from eating contaminated fish.  

How is this indicator used in NARS? 

The National Coastal Condition Assessment collects ecological fish tissue contaminant data.  Data is available on the NARS data page. Below the table you access assessment information in current reports. 

NLA NRSA NCCA NWCA Indicator Type
    X   Core Indicator
        Research Indicator

National Coastal Condition Assessment Web Report – Coming Soon. 

National Aquatic Resource Surveys

  • Background
    • Indicators
    • Manuals
    • Map of Sampled Sites
  • NARS Data
    • Journal Articles
    • Applying the Data
    • LakeCat
    • StreamCat
  • National Coastal Condition Assessment
  • National Lakes Assessment
  • National Rivers and Streams Assessment
  • National Wetland Condition Assessment
  • Outreach Materials
Contact Us about National Aquatic Resource Surveys
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on January 8, 2025
  • Assistance
  • Spanish
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • French
  • Haitian Creole
  • Korean
  • Portuguese
  • Russian
  • Tagalog
  • Vietnamese
United States Environmental Protection Agency

Discover.

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

Connect.

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

Ask.

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

Follow.