The Endangered Species Act of 1973 (ESA) mandates all federal agencies to conserve listed species and to utilize their authorities in furtherance of the purposes of the ESA. The ESA provides specific mechanisms to achieve its purposes and Section 7 is one of those. Section 7 requires that federal agencies develop a conservation program for listed species and that they avoid actions that will further harm species and their critical habitat. The Section 7 consultation process applies to the second requirement.

Section 7 directs all federal agencies to ensure that any action they authorize, fund, or carry-out does not jeopardize the continued existence of an endangered or threatened species or designated or proposed critical habitat (collectively, referred to as protected resources).  In order to meet this goal, federal agencies must review their actions and determine whether the action may affect federally listed and proposed species or proposed or designated critical habitat, which is typically done during the NEPA process or the CEQA process. To accomplish the impact analysis, agencies must request from the US Fish and Wildlife Service (USFWS) a list of species and critical habitat that may be in the project area or they can request USFWS’s concurrence with their species list. There is a convenient online system for requesting your USFWS species list:

In California, the Department of Fish and Wildlife (CDFW) keeps a database of occurrence records for federally listed species known to occur in the state (subscription required), called the California Natural Diversity Database (CNDDB):

Once a species list is obtained or verified as accurate, agencies need to determine whether their actions may affect any of those species or their critical habitat. If no species or their critical habitat are affected, no further consultation is required. If they may be affected, consultation with the USFWS is required. This consultation will conclude either informally or through formal consultation with a Biological Opinion (BO) provided. The Flowchart below shows the different levels of consultation.


Informal Section 7 Consultation

The Section 7 process usually begins as informal consultation. An agency, in the early stages of project planning, approaches the USFWS and requests informal consultation when a listed species may be affected by the action. Discussions between the two agencies may include what types of listed species may occur in the proposed action area, and what effect the proposed action may have on those species.

If the agency, after discussions with the USFWS, determines that the proposed action is not likely to affect any listed species in the project area, and if the USFWS concurs, the informal consultation is complete and the proposed project moves ahead. Typically, this is documented with a written concurrence letter.

If, after informal consultation (or after other analysis such as NEPA, Section 404, or CEQA) it appears that the agency’s action may affect a listed species, that agency may then prepare a Biological Assessment (BA) to assist in its determination of the project’s effect on a species.

Biological Assessment (BA)

A BA is a report that includes enough information to determine if a listed species will be adversely affected by the project. To BA must include a description of the project and project area, physical and biological attributes in the “action area” (area to be affected by the project), an analysis of the habitat quality and known presence of all listed species that may be present, and an analysis of the potential impacts from the project to listed species or habitat.

Following the analysis described above, you need to make a Section 7 finding for proposed or listed species and proposed or designated critical habitat that may be present in the action area. Your section 7 conclusion should be explicit. Generally, one of the following three determinations will apply:

  • “No effect” means there will be no impacts, positive or negative, to listed or proposed resources. Generally, this means no listed resources will be exposed to action and its environmental consequences. Concurrence from the USFWS is not required.
  • “May affect, but not likely to adversely affect” means that all effects are beneficial, insignificant, or discountable. Beneficial effects have contemporaneous positive effects without any adverse effects to the species or habitat. Insignificant effects relate to the size of the impact and include those effects that are undetectable, not measurable, or cannot be evaluated. Discountable effects are those extremely unlikely to occur. These determinations require written concurrence from the USFWS.
  • “May affect, and is likely to adversely affect” means that listed resources are likely to be exposed to the action or its environmental consequences and will respond in a negative manner to the exposure.

When an agency determines, through a BA or other review, that its action is likely to adversely affect a listed species, the agency submits to the USFWS a request for formal Section 7 consultation along with the BA.

Formal Section 7 Consultation

During formal consultation, the USFWS and the agency share information about the proposed project and the species likely to be affected. Formal consultation may last up to 90 days, after which the USFWS will prepare a Biological Opinion (BO) on whether the proposed activity will jeopardize the continued existence of a listed species. The USFWS has 45 days after completion of formal consultation to write the opinion.

Biological Opinion (BO)

In making a determination on whether an action will result in “jeopardy”, the USFWS begins by looking at the current status of the species, or “baseline.” Added to the baseline are the various effects – direct, indirect, interrelated, and interdependent – of the proposed action. The USFWS also examines the cumulative effects of other non-Federal actions that may occur in the action area, including state, tribal, local, or private activities that are reasonably certain to occur in the project area. The USFWS’s analysis is then measured against the definition of jeopardy. Under the ESA, jeopardy occurs when

an action is reasonably expected, directly or indirectly, to diminish a species’ numbers, reproduction, or distribution so that the likelihood of survival and recovery in the wild is appreciably reduced.


When the USFWS makes a jeopardy determination, it also provides the consulting agency with reasonable and prudent alternative actions. These alternatives are often developed with input and assistance from the agency itself. Alternatives must:

  • be consistent with the purpose of the proposed project
  • be consistent with the agency’s legal authority and jurisdiction
  • be economically and technically feasible
  • in the USFWS’s opinion, avoid jeopardy
Incidental Take Statement

In some cases, the USFWS finds that an action may adversely affect a species, but not jeopardize its continued existence. When this happens, the USFWS prepares an incidental take statement within the BO for the proposed project. Under most circumstances, the ESA prohibits take, which is defined as harming (includes killing) or harassing a listed species. Incidental take – take that results from a federal action but is not the purpose of the action – may be allowed when the USFWS approves it through an incidental take statement. The statement includes the amount or extent of anticipated take due to the action, reasonable and prudent measures to minimize the take, and terms and conditions that must be observed when implementing those measures.

After a BO is Issued

After the USFWS issues its BO, the agency then decides how to proceed. With an BO that determines adverse effects, the agency can adopt the reasonable and prudent measures outlined in an incidental take statement and proceed with the project.

If the USFWS makes a jeopardy determination, the agency has several options:

  • implement one of the reasonable and prudent alternatives;
  • modify the proposed project and consult again with the USFWS;
  • decide not to undertake (or fund, or authorize) the project;
  • disagree with the opinion and proceed;
  • apply for an exemption.

An agency may apply for an exemption if it believes it cannot comply with the requirements of the BO. The application is considered by the Endangered Species Committee, composed of Cabinet-level members from various federal agencies and administered by the Interior Department’s Assistant Secretary for Policy, Management and Budget. To be considered by the Committee for an exemption, an agency must have carried out the consultation in good faith and made a reasonable effort to develop and consider modifications or alternatives to the proposed action. It must also have completed a BA, and refrained from making any irreversible or irretrievable commitment of resources to the project during consultation.