January 20, 2022 — Alright, stop the presses, folks. What is a 5-year review? What’s a distinct population segment? How and why are the beloved Southern Resident killer whales (SRKWs) still in danger of becoming extinct? Let’s break this down.
What Does This All Mean?
First, let’s explore the factors we consider for a species to be placed on the Endangered Species list:
- Present or threatened destruction, modification, or curtailment of its habitat or range
- Over-utilization of the species for commercial, recreational, scientific, or educational purposes
- Disease or predation
- Inadequacy of existing regulatory mechanisms
- Other natural or human-caused factors affecting its continued existence
SRKW were listed as endangered in 2005. The main threats being prey availability, pollution and contaminants, effects from vessels and sound, as well as small population size and vulnerability to oil spills. The Endangered Species Act requires a review of species listed under the Act every 5 years. Why? This ensures that the listed species retain an appropriate level of protection under federal law.
The SRKW are also what is called a “distinct population segment” of a tentative subspecies of North Pacific resident killer whales. Killer whales are found in every ocean and are all still known by the same species name, Orcinus orca. The SRKW are “distinct” based on their genetics, geographic range, and behavioral and cultural diversity compared to other resident orca whales in the North Pacific. They are the only resident killer whales that use coastal waters as far south as California. While many other orcas are doing well, the Southern Residents are not.