Water Quality Issues

Poor water quality can harm fish, wildlife and their habitat. Many things are known to cause poor water quality including:

  • sedimentation,
  • runoff,
  • erosion,
  • dissolved oxygen,
  • pH,
  • temperature,
  • decayed organic materials,
  • pesticides, and
  • toxic and hazardous substances.

For example, the water that drains off of agricultural sites and into surrounding ponds or ditches is known to cause the build up of toxins as well as reproductive and developmental problems in shorebirds, waterfowl, and fish.

Almost half of the species listed as endangered or threatened are water-dependent. Water-dependent means they:

  1)   Eat primarily aquatic plants or animals


  2)  Live in water
    a) throughout their entire life, or
    b) in one or more of the life stages (for example a frog's larval, or tadpole, stage.)

Given these numbers, improving and protecting water quality becomes important if we are to protect endangered species. That is why we work with States, local communities, and other Federal agencies to ensure that any water quality standards they set protect fish and wildlife.

The Service has signed a Memorandum of Agreement (MOA) with the Environmental Protection Agency and National Marine Fisheries Service addressing interagency coordination under the Clean Water Act and Endangered Species Act. [2.5MB PDF].

The objective of the Clean Water Act is to restore and maintain the chemical, physical, and biological integrity of the Nation's waters. The goal of this law is to establish national water quality that provides for the protection of fish, shellfish, and wildlife as well as providing safe recreational use of the Nation's water bodies.

Fish and Wildlife Service Links:

U.S. Geological Survey Links:

U.S Environmental Protection Agency Links: Other Federal Links: Other Water Quality-related Links:
Last updated: April 17, 2014