Endangered Species Act (College Board AP® Environmental Science): Study Guide

Endangered Species Act (ESA)

Background

• Enacted in response to the rapid decline of wildlife populations in the U.S., particularly due to habitat loss, pollution, and overhunting

  • In the 20th century, species like the bald eagle, grizzly bear, and whooping crane were pushed to the brink of extinction

  • There was increasing recognition that biodiversity loss threatened both ecosystem stability and human well-being

• The ESA was created to:

  • Protect species at risk of extinction

  • Preserve the ecosystems upon which they depend

  • Prohibit activities that harm listed species or their habitats

• It is considered the strongest environmental law in the U.S. for protecting biodiversity

Key Dates

• 1973: Endangered Species Act passed and signed into law

• 1982, 1988, 2004: Notable amendments improved enforcement, public involvement, and habitat protection

How the Endangered Species Act relates to the environment

• Provides two primary classifications:

  • Endangered: species in danger of extinction throughout all or a significant portion of their range

  • Threatened: species likely to become endangered in the foreseeable future

• Administered by:

  • U.S. Fish and Wildlife Service (terrestrial and freshwater species)

  • National Marine Fisheries Service (marine species)

• Requires the development of Recovery Plans and designates Critical Habitat areas for conservation

Evaluation

• Successes:

  • Has prevented the extinction of over 99% of species listed under the Act

  • Successfully aided the recovery of species like the bald eagle, American alligator, and gray wolf

  • Requires scientific evidence before species are added or removed from the list

  • Emphasizes ecosystem conservation, not just individual species

• Challenges:

  • Listing process can be politically and legally contentious

  • Some argue the Act is too slow or reactive, protecting species only once they’re already in severe decline

  • Critical habitat designations can conflict with land development or resource use

  • Enforcement and funding are inconsistent, especially at the state level