A single species name that hides deeply divergent fates: globally data deficient as a whole, while one iconic Pacific Northwest population — the Southern Residents — teeters at fewer than 75 individuals.
Orcas (Orcinus orca) are found in every ocean, and the IUCN currently assesses the species globally as Data Deficient — reflecting genuine scientific debate over whether several distinct "ecotypes" (fish-eating residents, mammal-eating transients, and others) should be classified as separate species or subspecies, each with very different population trajectories.
The Southern Resident killer whale population of the Salish Sea (Washington State/British Columbia) numbered approximately 73 individuals as of the 2024 census — near the lowest count since surveys began in the 1970s, and listed as Endangered under both the U.S. Endangered Species Act and Canada's Species at Risk Act.
Source: Center for Whale Research, 2024 annual censusSouthern Resident orcas are highly specialized, feeding primarily on Chinook salmon even when other prey is available. This dietary specialization makes them unusually vulnerable to salmon population declines, in contrast to transient ("Bigg's") orcas in the same waters, which feed on marine mammals and have grown in number over the same period.
Recovery plans in the U.S. and Canada focus on Chinook salmon habitat restoration, vessel-approach distance regulations (including seasonal no-go zones in parts of the Salish Sea), and continued restrictions on legacy pollutants. Progress has been slow: the population has not shown sustained growth despite two decades of formal protection.
Taxonomic uncertainty (how many orca "types" constitute distinct species) complicates any single global population assessment. Untangling the relative weight of prey decline versus pollution versus noise disturbance in the Southern Residents' lack of recovery remains an active area of research, since the three pressures interact and are difficult to isolate in the field.