Southern Resident Orcas
Photos: A pod of Southern Resident orcas in British Columbia Canada. Credit: Karoline Cullen/Shutterstock.com; Orca spyhopping. Credit: Monika Wieland Shields/Shutterstock.com.
A very special population of critically endangered orcas, called Southern Resident killer whales, live in the coastal ocean waters off Northern California, Oregon, Washington, and Vancouver Island in British Columbia. These unique orcas are critically endangered with extinction, with less than 75 individuals remaining. Yet two recently born baby orcas provide a glimmer of hope. If we do not act quickly and decisively, however, this genetically distinct orca population is likely to be doomed to extinction. We need to do everything we can to save them.
A Unique Population of Orcas
Unlike other orca populations, the Southern Residents are specialized to exclusively hunt salmon. While other groups of orcas may eat marine mammals or sharks, on average 99 percent of a Southern Resident orca’s diet is comprised of salmon, particularly Chinook salmon.
From late spring through fall, Southern Resident killer whales are usually seen chasing salmon in the protected ocean waters off the Pacific Northwest coast, including the Salish Sea Regions of the Strait of Juan de Fuca, Strait of Georgia, and Puget Sound. In recent years, however, because of a lack of food, too much noise, or both, they are spending fewer days in the Salish Sea. Southern Residents have also been observed as far south as Monterey Bay, California.
Southern Resident orcas consist of one clan, each with distinct vocal dialects. Within the clan, there are three pods (J, K, L) which socialize internally, and migrate and forage as distinct groups. They are heavily researched and monitored and every orca has been given its own individual name.
Endangered with Extinction
Figure: Southern Resident orcas have continued to decline since being listed as endangered.1 Note that this chart reflects data as of January, 2020 and does not reflect the two recent births.
Southern Resident killer whales are threatened by vessel noise and interactions, contaminants, and lack of available prey. Of these threats, a lack of their favorite prey — Chinook salmon — is the number one threat to the recovery of the Southern Residents. Over two-thirds of the orcas’ pregnancies failed between 2008 and 2014 because moms were not getting enough salmon to eat.2 In addition, many females in the population are nearing the age where they will no longer be able to reproduce. This is compounded by the fact that baby orcas usually only have a 50 percent chance of survival when they are born, and those chances decline when the calves are unable to receive enough nutrition.
Many Chinook populations have declined and dozens are already extinct,3 due to dams on salmon streams, habitat loss and too much fishing pressure. In its Southern Resident killer whale recovery plan, the National Marine Fisheries Service states, “Perhaps the single greatest change in food availability for resident killer whales since the late 1800s has been the decline of salmon in the Columbia River basin.”4 The Columbia River Basin once produced between 10 and 16 million salmon annually and the Snake River has some of the most intact habitat available for spawning salmon.
Photo: In 2018, 3-year old Scarlet, or J50, was so emaciated that she lost the fat at the base of her head – what scientists call “peanut head.” She was declared dead September 13, 2018. Image credit: Katy Foster/NOAA Fisheries Permit No. 18786-03
We Can Recover Salmon and Save Orcas
Oceana is advocating for a number of actions to protect and recover these endangered orcas including protecting the orcas’ habitat and recovering Chinook salmon so these animals have enough to eat.
In a recent letter to the Pacific Fishery Management Council and National Marine Fisheries Service, Oceana advocated for a number of actions to help leave as many Chinook salmon as possible for these animals to eat, an essential first step in turning things around for Southern Resident orca. The fishery council is actively considering precautionary conservation measures to ensure enough Chinook salmon are left in the ocean for orcas during times of low abundance. Plus, the National Marine Fisheries Service has proposed expanding “critical habitat” for Southern Residents along the outer coast of Washington, Oregon and Northern California.
Ultimately, a broad set of comprehensive actions are needed to address the threats facing orcas including the lack of prey, vessel noise and disturbance, and contaminants. To address the lack of prey, attention must be given to the Columbia and Snake Rivers, where seven of the top 15 “priority Chinook stocks” for Southern Resident orca originate.5
We support improving fish passage and restoring habitat in the Columbia Basin to help recover threatened priority Chinook runs, restore salmon to healthy and naturally productive levels and increase prey for Southern Resident orcas. The survival of juvenile salmon can be increased if the fish can be aided past dams by going over spillways, as opposed to going through the powerhouse, which contains electricity-generating turbines and is increasingly deadly for fish. Salmon survival can also be greatly boosted by removing four dams on the lower Snake River.
Figure: Spring Chinook returns and expected spring Chinook returns to the mouth of the Columbia River under the current federal Columbia River hydropower system spill management framework (status quo) and under revised spill and Lower Snake River (LSR) dam breach management scenarios.6 Breaching the four lower Snake River dams and increasing spill over other dams – to 125% “total dissolved gas” – is expected to result in up to one million adult spring Chinook returning to the mouth of the Columbia. The range in estimates reflect returns under variable environmental conditions.
While lower Snake River dam removal and increased spill are big, difficult changes, there are pathways forward to get there that will ultimately benefit people, fish and orcas. Now is the time to advance solutions that help people and communities and allow for healthier, more resilient ecosystems for Chinook and dependent wildlife. If bold and comprehensive actions are not taken soon, these animals may be lost forever.
To learn more about the plight of Southern Resident orcas check out:
1. Center for Whale Research, https://www.whaleresearch.com
2. Wasser, SK, JI Lundin, K Ayres, E Seely, D Giles, K Balcomb, et al. 2017. Population growth is limited by nutritional impacts on pregnancy success in endangered Southern Resident killer whales (Orcinus orca). PLoS ONE. https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0179824
3. Gustafson, RG.; R Waples, JM Myers, LA Weitkamp, GJ Bryant, OW Johnson, and JL Hard. 2007. Pacific Salmon Extinctions: Quantifying Lost and Remaining Diversity. Publications, Agencies and Staff of the U.S. Department of Commerce. 438. http://digitalcommons.unl.edu/usdeptcommercepub/438
4. NOAA and WDFW 2018. Southern Resident Killer Whale Priority Chinook Stocks. Available: http://www.westcoast.fisheries.noaa.gov/publications/protected_species/marine_mammals/killer_whales/recovery/srkw_priority_chinook_stocks_conceptual_model_report___list_22june2018.pdf
5. National Marine Fisheries Service. 2008. Recovery Plan for Southern Resident Killer Whales (Orcinus orca). National Marine Fisheries Service, Northwest Region, Seattle, Washington. At: II-82.
6. M. DeHart (Fish Passage Center). As presented in: LSR dam panel discussion and webinar (September 27, 2018). Based on CSS (Comparative Survival Study). 2017. Comparative Survival Study of PIT-tagged Spring/Summer/Fall Chinook, Summer Steelhead, and Sockeye. December 2017. 834 p. Available: http://www.fpc.org/documents/CSS/CSS_2017_Final_ver1-1.pdf