Periodic Status Review for the Orca (2024)

Killer whales (Orcinus orca) are a large, black and white member of the dolphin family. The three ecotypes that frequent Washington waters, fish-eating Southern Residents, marine mammal-eating transients, and offshores, are distinguished primarily by prey selection and habitat use. Southern Resident killer whales (SRKW) were listed as federally endangered under the Endangered Species Act in 2005, and the species was listed as endangered in Washington State in 2004. As NOAA points out in its 5-year review for SRKW, some of the downlisting criteria have been met, but the population continues to shrink. As of the July 2023 census, only 75 individuals remain.

Many partners are acting to aid the recovery of SRKW. Primary stressors on the population include reduced prey availability and size, contaminants, disturbance from vessel noise and activity, and these have cumulative and interacting effects on the population. Additionally, small numbers of reproductively active individuals in the population over generations have led to inbreeding depression, which reduces the whales’ resilience and has contributed further to population decline. Given the difficulty of isolating impacts from the multitude of stressors, efforts must be aggressive and multi-faceted. In 2018, Governor Inslee signed an executive order that included formation of a Southern Resident Orca Task Force to make recommendations for immediate and longer-term actions to ensure SRKW recovery. Those recommendations have helped galvanize support, partnerships, and funding, and management actions have increased as a result.

However, the main threats persist, some are increasing, and recovery won’t be evident for years to decades. In addition, there are the growing stressors of climate change and human population growth on the ecosystem. Due to the small population of Southern Resident killer whales, long maturation and recruitment times, and continued threats, we recommend the species maintain endangered status in Washington.