Infographic: How and Why Southern Resident Killer Whales Were Listed As Endangered
Under the Endangered Species Act, the federal government has the responsibility to conserve endangered and threatened species and their critical habitats.
NOAA Fisheries and the U.S. Fish and Wildlife Service share responsibility for implementing the Endangered Species Act (ESA). NOAA Fisheries is responsible for most marine and anadromous species.
To implement the ESA, we rely on the best available science. We work with international federal, tribal, state, and local agencies, as well as nongovernmental organizations and private citizens. The infographic below details the process and timeline to complete the final determination to list the Southern Resident killer whale distinct population segment (DPS) as endangered.

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Listing History
Listing Petition (2001)
The Center for Biological Diversity and other non-profit groups sent a petition to NOAA Fisheries to list Southern Resident killer whales as threatened or endangered.
90-Day Finding (2001)
NOAA Fisheries made a 90-day determination that the information provided warranted a review of whether it should be listed.
12-Month Finding (2002)
At first, NOAA Fisheries determined that Southern Resident killer whales did not meet the criteria to be a distinct population segment (DPS) because they were not different enough from all other killer whales globally. So, NOAA Fisheries published a 12-month finding that the Southern Residents were not a DPS or warranted to be listed. This decision was challenged in court.
Proposed Listing (2004)
A judge’s order in 2003 sent the listing decision back to NOAA Fisheries to reconsider the scientific information. Considering Southern Residents more locally, as compared to North Pacific Residents, NOAA Fisheries determined they were a DPS and proposed to list them as threatened.
Final Ruling (2005)
NOAA Fisheries requested public comments on the proposed rule to list the Southern Resident killer whale DPS as threatened. After public and peer reviews, NOAA Fisheries published a final rule listing them as endangered.
Benefits to Being Listed
Legal Protection
The ESA provides federal protection for listed species, making some activities illegal, such as harassing, harming, or killing a listed species.
Species in the Spotlight (2015)
Southern Resident killer whales were identified as a Species in the Spotlight. This initiative provides additional attention to species most at risk of extinction. A priority action plan was created for the Southern Residents.
Recovery Plan (2008)
The threats to Southern Resident killer whales include prey availability, environmental contaminants, vessel noise, and small population size. After listing, a recovery plan was finalized for Southern Resident killer whales. The plan outlines necessary actions that interested parties can take to support the recovery of the population and minimize the effects of threats.
Designated Critical Habitat (2006 & 2021)
The ESA requires the designation of critical habitat when it is essential to the conservation of the species. Within a year of listing, NOAA Fisheries designated 2,560 square miles of inland waters in Washington that were essential for conservation. After more research,15,910 square miles of coastal waters of Washington, Oregon, and California were added as critical habitat.
Key Terms
Distinct Population Segment
Under the Endangered Species Act, a distinct population segment—or DPS—is a vertebrate population or group of populations that is discrete from other populations of the species and significant in relation to the entire species.
Critical Habitat
Specific areas within the geographical area occupied by the species at the time of listing that contain physical or biological features essential to the conservation of the species and that may require special management considerations or protection; and specific areas outside the geographical area occupied by the species if the agency determines that the area itself is essential for conservation.