2021 Southern Resident Killer Whales (Orcinus orca) 5-Year Review: Summary and Evaluation
January 04, 2022
The Southern Resident killer whale Distinct Population Segment was first listed as Endangered in 2005.
The Southern Resident killer whale Distinct Population Segment (DPS) was listed as endangered under the Endangered Species Act (ESA) in 2005. In the listing, the National Marine Fisheries Service (NMFS) identified three main threats to their survival: 1) scarcity of prey, 2) high levels of contaminants from pollution, and 3) disturbance from vessels and sound. As of 1 July 2021 after the summer census, there were only 74 individuals left in the population (CWR 2021). Since the summer census, one adult male whale (K21) is presumed dead, so at the time of this review there are currently 73 individuals in the population. Their small population size and social structure also put them at risk for a catastrophic event, such as an oil spill, that could affect the entire population. Updates regarding research and management actions for the primary threats (prey, pollution, and vessels) are discussed below and evaluated alongside recovery criteria to assess recovery progress. This review fulfills our requirement under Section 4(c)(2) of the ESA to conduct a review of listed species at least once every five years to ensure that the listing of these species remains accurate.