EXECUTIVE SUMMARY:
- Historically, the three Southern Resident orca pods – J, K, and L pods – have fed on an abundance of large, fatty Chinook salmon.
- Southern Resident orcas are listed as endangered in both the U.S. (listed in 2005) and Canada (listed in 2003). The lack of Chinook salmon is the single greatest threat to the survival of the Southern Resident orcas. Only 74 individual Southern Resident orcas survive today (according to the Center for Whale Research’s annual census of the Southern Resident population completed in July 2025).
- Snake River Spring/Summer Chinook and Snake River Fall Chinook as well as many Columbia-Basin salmon runs are ranked in the top 10 Priority Chinook stocks for orca recovery.
- Research conducted by NOAA shows that over 50% of the seasonal diet of Southern Resident orcas in coastal waters originates from the Columbia River.
- Research conducted by Orca Behavior Institute, shows an increase in the presence of Bigg's orcas in the Salish Sea, likely related to food abundance. Bigg's have enough food and are thriving, while Southern Residents are struggling, with less food abundance being the likely reason.
- Scientists agree that recovering Chinook salmon is essential for the recovery of Southern Residents. Key actions to help achieve abundant salmon include removing the four lower Snake River dams to restore Snake River salmon runs, restoring salmon habitats across the Columbia-Snake River Basin, and protecting marine habitats in order to increase Southern Residents’ ability to reproduce and increase their survival rate.
Critically endangered Southern Resident orcas need more Chinook salmon
K25 with a salmon © Monika Wieland Shields
Highly social and intelligent Southern Resident orcas have roamed the coastal waters of the Pacific Northwest and have held cultural and spiritual significance for Northwest Tribes since time immemorial. The three Southern Resident orca pods – J, K, and L– have historically fed on an abundance of large, fatty Chinook salmon. However, today, Columbia-Snake River Basin Chinook salmon populations are rapidly declining, and Southern Residents are also facing extinction due to a lack of food throughout their range. Only 74 individual Southern Resident orcas survive today (according to the Center for Whale Research’s annual census of the Southern Resident population completed in July 2025).
Scientists agree there is an urgent need to remove the four lower Snake River dams to restore Snake River salmon runs, restore salmon habitats across the Columbia-Snake River Basin, and protect marine habitats in order to increase Southern Residents’ ability to reproduce and increase their survival rate.
Who are the Southern Resident orcas?
The three Southern Resident orca pods, known as J, K, and L pods, are a genetically and culturally distinct population unlike other orca communities found within the Pacific Northwest. Southern Residents communicate using their own exclusive dialect, typically traveling in large, extended family groups led by matriarchs, and stay in these extended family groups their entire lives. Historically, Southern Residents traveled, foraged, and socialized throughout the inland waters of the Salish Sea from late spring through late summer feeding on Chinook salmon.1
Columbia-Snake River Basin salmon importance to Southern Resident orcas
L84 with a salmon Sept. 29 2011. Photo by Dave Ellifrit of the Center for Whale Research
Southern Residents are the original fishers of the Pacific Northwest waters, co-evolving over millennia with their preferred prey, Chinook salmon. Chinook salmon are the primary food source for the endangered Southern Residents, accounting for 50%-100% of their diet depending on the season. The Columbia-Snake River Basin and the Fraser River were historically the two most important sources of salmon for these orcas. Columbia-Snake River Basin Chinook salmon account for more than half of the Chinook consumed by the orcas during from fall through spring while they’re in coastal waters.2
Southern Resident orcas are listed as endangered in both the U.S. (listed in 2005) and Canada (listed in 2003). The lack of Chinook salmon is the single greatest threat to the survival of the Southern Resident orcas. In 2016, the National Oceanic and Atmospheric Administration (NOAA) identified Southern Resident orcas as one of eight species most likely to go extinct in the near future unless immediate action is taken.
Data from the Center for Whale Research has shown that Southern Resident mortality is correlated with coast-wide Chinook salmon abundance. Drone research from SR3 has shown that Southern Residents are sometimes visibly thin, and a study from the U.W. Conservation Canine program discovered a 69% miscarriage rate primarily due to lack of food. This research indicates that restoring salmon for Southern Residents should be our top priority.
In 2018, NOAA Fisheries and the Washington Department of Fish and Wildlife developed a list of Chinook salmon stocks identified as important to Southern Residents’ survival and required priority actions to increase critical prey for these orcas. Snake River Spring/Summer Chinook and Snake River Fall Chinook, as well as many Columbia-Basin salmon runs, are ranked in the top 10 Priority Chinook stocks for orca recovery.
Despite years of recovery efforts to restore Southern Residents and salmon, they both teeter on the brink of extinction. As fewer salmon return to the ocean, these iconic orcas are starving, and their population has declined to record low numbers – only 74 individuals are alive today – 27 in J Pod, 14 in K Pod, and 33 in L Pod.
K Pod has the highest likelihood of going extinct in the next half century, said Michael Weiss, research director with the Center for Whale Research in the Seattle Times article: Southern resident K pod falls to lowest number since counts began
“If we lose K Pod we’ve both kind of scratched off one of the criteria for ever delisting the southern residents,” Weiss said, “and we’ve lost a cultural group, a cultural lineage, forever that’s not coming back. There are calls that K Pod makes that the other groups rarely ever make. So there are these sounds that are kind of inherent to the Salish Sea that would never be made again.”
K pod especially spends a lot of time on the outer coast of Washington and goes all the way down to Monterey Bay to fish. One lever to pull to boost southern resident recovery, Weiss said, would be breaching the lower four Snake River dams.
Hope for Southern Residents informed by Bigg’s orcas' recovery journey
The Southern Residents and Bigg’s orcas frequent the same waters in the Salish Sea and along the Pacific Coast. They are still considered the same species but are different ecotypes, meaning they are two distinct types of orcas that differ in size, appearance, pod structure, diet, behavior, culture, acoustics, and genetics.3,4
As much as they are different, Bigg’s orcas and Southern Residents encounter the same threats, including pollution, noise and disturbances, and both have a history of being captured for display, all of which impacted their population.
Both Bigg’s orcas (listed as threatened in Canada) and Southern Residents experience some of the same threats; however, Bigg’s are thriving, overcoming threats, and increasing in population size. Why?
Research conducted by Orca Behavior Institute, shows an increase in the presence of Bigg's orcas in the Salish Sea, likely related to food abundance. Bigg's have enough food and are thriving, while Southern Residents are struggling, with less food abundance being the likely reason.
The Southern Residents have a very long history and knowledge of foraging for salmon in the Salish Sea and along the Pacific Coast, where Columbia-Snake River Basin Chinook salmon account for more than half of the Chinook provide Southern Residents’ winter diet.5
Since the decline of Chinook salmon, each of the Southern Resident pods have shifted their presence along their historical foraging range based on Chinook salmon runs.6,7 According to Orca Behavior Institute data with reports from Pacific Whale Watch Association, Orca Network, and other sighting groups and community scientists, between 2003 and 2023 there was a 76 drop in Southern Resident sightings in the Salish Sea. 20 years ago, the Southern Residents were spending an average of more than 80 days in the Salish Sea in the months of June through August. For 2019-2023, that average dropped to just 20 days. In 2025, Southern Residents were present a total of only 3 days from May through August. By comparison, the presence of Bigg’s orcas in the Salish Sea has increased 8 fold just in the last 10 years, and they have been documented every day so far in 2025.
For Southern Residents, the lack of salmon is by far the single greatest threat to their survival. For example, in the context of encountering pollution, when Southern Residents are not getting enough to eat, they are more susceptible to metabolizing their fat stores, releasing pollutants that circulate through their body, which makes them immune compromised.8 With the pollutants and lack of food in their bodies, it makes it harder to forage for food, and overall their quality of life declines.
In contrast, Bigg's absorb more toxics because the food (seals and seal lions) they eat are higher in the food web, but they are still healthier because they get enough to eat and therefore don't need to metabolize fat stores. Bigg’s population size continues to increase due to finding enough food, and they have been increasingly using the Salish Sea over the last 30 years, as shown in the annual Bigg’s sighting map above, where a total of 1413 sightings of Bigg’s were seen in 2023.
Contrasting the Bigg’s and Southern Resident maps shows us that when we restore Chinook salmon for Southern Residents, they can live healthier longer lives and thrive similar to Bigg’s orcas, despite other threats they encounter.
Restoring a free-flowing lower Snake River to recover Southern Resident orcas and salmon
Tahlequah's Respair J35 and J57 © Britt Freda
Since time immemorial, Southern Residents have a deep interconnected relationship with salmon, in which salmon has heavily influenced Southern Residents’ culture, communication, and genetics.
However, today, orcas are finding less and less salmon in their traditional and historical foraging areas, causing Southern Residents significant stress about finding enough food for their pod and often becoming visibly thin. Their mortality is linked to not having enough Chinook salmon as well as not having enough strength to overcome other threats that they face.
Scientists have identified that Columbia/Snake River salmon are among the priority Chinook salmon that are essential to the recovery of Southern Residents. It is critical for Southern Residents to feed on salmon throughout their entire foraging range and also throughout the entire year, especially in the winter and early spring when orcas move toward the mouth of the Columbia Basin.
Scientists agree that recovering Chinook salmon is essential for the recovery of Southern Residents. Key actions to help achieve abundant salmon include removing the four lower Snake River dams to restore Snake River salmon runs, restoring salmon habitats across the Columbia-Snake River Basin, and protecting marine habitats in order to increase Southern Residents’ ability to reproduce and increase their survival rate.
FURTHER INFORMATION:
References:
1. Shields MW. 2023. 2018–2022 Southern Resident killer whale presence in the Salish Sea: continued shifts in habitat usage. PeerJ 11:e15635 https://doi.org/10.7717/peerj.15635
2, 5. Hanson MB, Emmons CK, Ford MJ, Everett M, Parsons K, Park LK, et al. (2021) Endangered predators and endangered prey: Seasonal diet of Southern Resident killer whales. PLoS ONE 16(3): e0247031. https://doi.org/10.1371/journal.pone.0247031
3. Whale and Dolphin Conservation: Meet the different types of orcas
4. Orca Conservancy: The killer whales of the Pacific Northwest
6.Shields, MW, Lindell J, Woodruff K, (2018) Declining spring usage of core habitat by endangered fish-eating killer whales reflects decreased availability of their primary prey. Pacific Conservation Biology 24, 189-193. https://www.publish.csiro.au/PC/PC17041
7. Shields MW. 2023. 2018–2022 Southern Resident killer whale presence in the Salish Sea: continued shifts in habitat usage. PeerJ 11:e15635 https://doi.org/10.7717/peerj.15635
8. Wild Orca (2022) Hot Water Report: Interview with Dr. Deborah Giles - Science and Research Director at Wild Orca
