How the U.S. Government Defines Recovery of Endangered Species

The Kemp’s ridley sea turtle, pictured here, is listed under the U.S. Endangered Species Act and is the subject of a bi-national recovery plan prepared jointly between the U.S. and Mexico. © Doug Perrine /

The Kemp’s ridley sea turtle, pictured here, is listed under the U.S. Endangered Species Act and is the subject of a bi-national recovery plan prepared jointly between the U.S. and Mexico. © Doug Perrine /


The United States Endangered Species Act (ESA), although a domestic statute, envisions protecting and conserving species wherever they occur if such species are considered in danger of extinction throughout all or a significant portion of their range (endangered) or are likely to become endangered within the foreseeable future (threatened). If a species occurs in a foreign nation, or crosses multiple jurisdictions, we work collaboratively with those nations through various international instruments. Currently, all sea turtles are listed under the ESA, except the Australian flatback.

An analogy to a species being listed under the ESA is a patient being taken to a hospital emergency room. The patient has become so ill or has been so critically injured that immediate and serious action is necessary to ensure his or her survival. Listing under the ESA has several implications. First and foremost, it is illegal for persons under U.S. jurisdiction to harm, harass, or kill any member of the species, or to harm its habitat, without going through a permitting process that seeks to avoid and minimize impacts. Federal agencies in the United States also must consult with either the National Marine Fisheries Service or the U.S. Fish and Wildlife Service if an action they are planning might affect a listed species. Special rules can be implemented to protect listed species, and a plan must be developed to guide species recovery. This recovery plan might be thought of as the treatment plan for the patient in the hospital.

The ESA defines recovery as “the process by which listed species and their ecosystems are restored and their future is safeguarded to the point that protections under the ESA are no longer needed.” The definition is deliberately vague because each species has unique life history traits and habitat needs and faces different threats. The point at which the species can be taken off the list of endangered or threatened species (that is, delisted) is spelled out in a series of recovery criteria that must address (1) biological or demographic parameters, such as number and arrangement of populations, abundance or trend within each population, or population structure that indicates the population will continue to increase or remain stable; and (2) threats-based parameters that indicate, when reached, that the threats to the species have been controlled or eliminated. Recovery plans then identify actions needed to achieve those criteria.

Ideally, we would like to see species recovered to historical levels and distribution. However, under the ESA, we delist a species when the protections provided by the ESA are no longer necessary, which often occurs before the species recovers to historical abundance. It is incumbent on experts who understand the species’ biological and habitat needs to define recovery for that species. In general terms, the species will be considered for delisting only when it is self-sustaining, well represented in sufficient numbers and populations, and sufficiently widespread so it maintains its adaptive potential and will not become endangered again.

Although recovery goals address an entire species, recovery occurs in different places at different rates in a mosaic across the species’ range. Where and how quickly accomplishments occur depend on many factors, including the nature of the threats facing the populations, the societal situation in the area, and the conservation efforts. Under the ESA, we have the ability to list species, subspecies, and distinct population segments (DPSs) of vertebrate species. Recently, we have begun to list some sea turtles as multiple DPSs. This listing will allow us to tailor recovery actions and goals more finely for these widespread species. Monitoring is key to understanding whether and where recovery is being accomplished for both the listed entity (whether species, subspecies, or DPS) and individual populations within it. Monitoring programs follow whether populations and threats are increasing or decreasing and also assess whether management actions are effective at achieving the goals for which they were designed. Effective monitoring measures recovery progress and provides a foundation for further recovery actions.

To date, no sea turtle species listed under the ESA have been determined to be “recovered” and subsequently delisted, and if a species were to be delisted, that would not be the last attention it would receive under the ESA. Just as a patient in a hospital emergency room would have follow-up monitoring and care after being released from the hospital, we are required to monitor a species for at least five years through the implementation of post-delisting monitoring plans. A post-delisting monitoring plan is developed in cooperation with affected states. Its primary goal is to monitor the species to ensure its status does not deteriorate. If either a substantial decline in the species or an increase in threats is detected, measures will be taken to reverse the situation, and relisting the population under an emergency listing is possible. Regardless of whether sea turtles remain listed under the ESA, they will continue to rely on our conservation efforts.