Southern Residents

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The southern resident orcas represent the smallest of the four resident communities within the eastern North Pacific Ocean. It is the only killer whale population listed as endangered by the U.S. Fish & Wildlife Service and is currently protected under the Endangered Species Act as of 2005. They are commonly referred to as the "orcas of the Salish Sea", "fish-eating orcas", or the "SRKW" population. Unlike other resident communities, the SRKW is only one clan (J) that consists of 3 pods (J, K, L). There are approximately 80 individuals that make up this small population. The world's oldest known killer whale, Granny or J2, belongs to J pod of the SRKW population. Estimated to have been born around 1911, J2 is about 103 years old.

The southern residents are commonly seen off the coast of Oregon, Washington, and Vancouver Island (British Columbia). Recently, they have been spotted as far south as the coast of central California and as far north as the coast of Haida Gwaii. During the Spring, Summer, and Fall, the southern residents tend to travel around the inland waterways of the Puget Sound, the Strait of Juan de Fuca, and southern Georgia Strait. Very little is known about their winter habits, however February 2015, the NOAA’s research team is spending three weeks following the Southern Residents to study their winter habits. Thus far it appears that they spend a great deal of time zig-zagging back and forth off the mouth of the Columbia River.

The size of all three Southern Resident pods was reduced in number from 1965-75 as a result of whale captures for marine park exhibition. At least 13 whales were killed during these captures, while 45 whales were delivered to marine parks around the world. Today, only Lolita “Tokitae” remains alive in captivity at the Miami Sequarium. Annual SRKW population updates occur on July 1 and December 31 each year. To learn more visit The Center for Whale Research.

There are three main contributing factors that have resulted in the population becoming endangered. They are as follows:

Decline in prey
The depletion of large quantities of fish in the marine environments, while personal fishing in the salmon’s upstream spawning grounds have further depleted stock replenishment. There are several reason for the decline of Chinook salmon. Learn more here.

Chemical contamination
Northwest killer whales are among the most contaminated marine mammals in the world, due to the high levels of toxic chemicals that accumulate in their tissues. Orcas can normally tolerate a high toxic load in times of plenty, contaminants are far more dangerous when the Orcas are starving. Toxins are stored in fat cells and when salmon numbers are low, Orcas metabolize their blubber for energy, releasing the toxins into their system.

While many chemicals can be found in the tissues of Orcas, the most common are DDT, an insecticide, polybrominated diphenyl ethers, or PBDEs and polychlorinated biphenyls or PCBs. Each of these have detrimental physiological effects on orca, and can be found in such high concentrations in dead individuals that those individuals must be disposed of in hazardous waste site.

Correlative evidence shows orca may be vulnerable to effects of PCBs on many levels. Research has identified PCBs as being linked to restricting development of the reproductive system in orcas and dolphins. High contamination levels leads to low pregnancy rates and high mortality in dolphins. Further effects include endocrine and immune system disruption, both systems being critical to mammalian health and survival. A study examining 35 Northwest orcas found key genetic alterations that caused changes to normal physiological functions. These genetic level interferences, combined with the varied effects of PCBs at other physiological levels, suggest these contaminants may be partially responsible for declines in Orca populations.

Marine noise
Noise and crowding from tour boats and larger vessels interrupt foraging behavior, or scare away prey. Also, the sonar used by some ships and submarines is enough to cause hemorrhaging, and subsequently, death in some individuals.

As locals to this amazing populace we find it one of our many duties to inform others of ways to protect these graceful powerful creatures! If you would like to know what you can do to assist captive and wild orcas please check out our How to Help page. And we appreciate you for taking the first step in becoming an Orca Defender!!

Southern Resident Orcas