• The Endangered Species Act: programs and authorities

    The Endangered Species Act was signed on December 28, 1973, and provides for the conservation of species that are endangered or threatened and the conservation of the ecosystems on which they depend. The ESA replaced the Endangered Species Conservation Act of 1969. It has been amended several times.


    A "species" is considered endangered if it is in danger of extinction throughout all or a significant portion of its range. A species is considered threatened if it is likely to become an endangered species within the foreseeable future.  There are approximately 1,990 total species listed under the ESA. Of these species, approximately 1,380 are found in part or entirely in the U.S. and its waters; the remainder are foreign species.


    NOAA Fisheries and the U.S. Fish and Wildlife Service share responsibility for implementing the ESA. Generally, USFWS manages land and freshwater species, while NMFS manages marine and "anadromous" species. NMFS has jurisdiction over 82 listed species.


    The ESA provides for different programs to conserve endangered and threatened species:


    • Listing (Section 4)
    • Critical Habitat (Section 4)
    • Recovery (Section 4) (Recovery Plans are issued under Section 4)
    • Cooperation with States (Section 6)
    • Interagency Consultation (Section 7) (Biological Opinions are issued under Section 7)
    • International Cooperation (Section 8)
    • Enforcement of the ESA (Section 9)
    • Permits & Habitat Conservation Plan (Section 10)

    For more information, see NOAA Fisheries or US Fish and Wildlife Service websites.








  • What is a biological opinion?

    The Endangered Species Act (ESA) requires that any federal agency proposing an action that may have an effect on an ESA-listed fish – issuing a permit, spending money, taking a direct action on fish habitat – consult with the U.S. Fish and Wildlife Service or NOAA Fisheries (i.e., regulatory agencies).


    The agency proposing the action (known as the action agency) will commonly complete a biological assessment on potential effects to the fish or its habitat and submit it to the regulatory agency(ies).  The regulatory agency then renders a Biological Opinion to the action agency making the proposal.


    The intent of a BiOp is to ensure that the proposed action will not reduce the likelihood of survival and recovery of a ESA-listed species. A BiOp usually also includes conservation recommendations that further recovery of the specific ESA-listed species.  The BiOp includes Reasonable and Prudent measures as needed to minimize any harmful effects, and may require monitoring and reporting to ensure that the action is implemented as described.


    A biological opinion is not an ESA recovery plan.  For wide-ranging BiOps, such as the one issued for the federal hydropower system in 2010, it can also serve as a component of a recovery plan. 


    BiOps for ESA-listed fish in the Columbia River Basin

    In the Columbia River Basin, there are 13 ESA-listed species of fish. See maps of their range. There are several BiOps that govern operation of the federal dams on the Columbia, Snake and Willamette Rivers to protect these fish.


    The individual species are called Evolutionarily Significant Units or Distinct Population Segments to indicate that each is genetically distinct.  Anadromous fish are born in freshwater, migrate to the ocean where they mature, and then return to the rivers and streams to spawn.  In the Columbia River Basin, listed anadromous fish include several stocks (ESUs) of chinook, coho, steelhead and sockeye.  



    Resident fish are fish that live their entire life in freshwater. ESA-listed resident fish in the Columbia River Basin include bull trout and Kootenai white sturgeon.