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Submitted by jenna.swartz on Fri, 02/11/2022 - 14:37
Audio file
Podcast Series

Dive In with NOAA Fisheries

NOAA Fisheries conducts world-class science to support sustainable marine life and habitats. Our podcast, “Dive In with NOAA Fisheries,” is about the work we do and the people behind it.

Podcast Transcript
00:00:00:00 (John Sheehan)
Killer Whales are one of the most unique and immediately recognizable marine mammals. And the Southern Resident Killer Whale in particular is an icon of the Pacific Northwest. Southern Resident Killer Whales are a big attraction to residents and visitors of coastal Washington State and are sacred to the indigenous people of the Lummi Nation. They’re also one of the most at-risk species and were listed as endangered in 2005 under the Endangered Species Act. This is “Dive In with NOAA Fisheries”. I’m John Sheehan and in honor of Whale Week happening now, we’re taking a pause from our series on scientific surveys to talk about the Southern Resident Killer Whales. Under the Endangered Species Act NOAA Fisheries is required to conduct a review every five years that summarized the best scientific information regarding the Southern Resident Killer Whale biology, status, and threats. The report has just been released. And to talk about it with us is the project lead, Doctor Megan Wallen, a marine mammal specialist at NOAA Fisheries West Coast Protected Resources Division. Doctor Megan Wallen welcome to “Dive In with NOAA Fisheries” Thanks so much for being here.
00:01:09:01 (Dr. Megan Wallen)
Thank. I’m happy to be here.
00:01:10:02 (John Sheehan)
Can we start with just a description of the Southern Resident Killer Whale population like where are they found and what are they like?
00:01:17:00 (Dr. Megan Wallen)
Yeah so, Killer Whales are of course an iconic species of the Pacific Northwest and the Southern Residents in particular are just one small population of Killer Whales. They live primarily in the inland waters of Washington State; known as the Salish Sea or the Puget Sound. But they actually have a pretty wide range. They’ve been spotted all the way from British Columbia in the north and close to southeast Alaska down to the Monterey Bay area of California. They also utilize the coast of Washington and Oregon a fair amount, especially in the winter.
00:01:50:07 (John Sheehan)
And what is it about this population that’s distinctive?
00:01:54:02 (Dr. Megan Wallen)
By definition the Southern Resident population is significant and discreet from other Killer Whales that are found in the north Pacific. They’re genetically distinct from other Killer Whales and they’re also behaviorally distinct. The Southern Resident Killer Whales have distinct vocalizations that can be distinguished by researchers and acoustic recordings that they take in the field. And they also have cultural traditions that are unique to them; one of which is a greeting behavior when two groups of whales approach each other they kind of line up head to head and stay that way for a little bit before merging and then coming together. And then they’re really active with lots of vocalizations. They also have unique knowledge of the local salmon runs that they feed on which is passed down through the matriline.
00:02:46:01 (John Sheehan)
Not to give them too many human characteristics but is it kind of like they have their own culture?
00:02:51:08 (Dr. Megan Wallen)
Yeah, you could say that. Cultural traditions is actually something that’s being characterized and studied by scientific researchers.
00:03:00:06 (John Sheehan)
And you said they have specific vocalizations. So, you can hear a recording of their Killer Whale song and know it was them?
00:03:09:02 (Dr. Megan Wallen)
That’s right. They have calls when they’re communicating with each other that are distinct and by the trained researchers they can identify that they are Southern Residents in those recordings.
00:03:20:02 (John Sheehan)
Can we hear one of them now?
00:03:21:07 (Dr. Megan Wallen)
Yeah, definitely.
00:03:23:05 (Killer Whales vocalizing and Dr. Megan Wallen)
(whale song) This is a recording of two different call types from “K” pod, which is one of the three pods of Southern Residents J, K and L.
00:03:43:09 (John Sheehan)
Doctor Wallen you led the recently completed five year review of the population. So, what did you find?
00:03:51:08 (Dr. Megan Wallen)
This review is something that’s required under the Endangered Species Act for us to do every five years to make sure that the listing status of the population; in this case endangered, is still accurate. So, the review showcases the progress that we’ve made in understanding the threats to the whales and actions that help to protect the whales. But the ultimate finding was that the population is still endangered. And this wasn’t a surprise to anyone. So, it really underscores the importance of their continued listing with only seventy three whales in the population at this time.
00:04:31:05 (John Sheehan)
How does that stack up historically?
00:04:33:07 (Dr. Megan Wallen)
Yeah so, when the Killer Whales were first listed as endangered in 2005 there were eighty eight individuals in the population. So, now at seventy three that’s a lot lower. So, you know the population isn’t doing too well. What we like to see is increased reproduction and survival of young calves cause that’s where we can kind of make the most difference in terms of growing the population. It’s been reported that there are three Southern Residents that are pregnant this year, which is exciting news although we have yet to see any of those females with their new calves. So, we’re anxiously awaiting what happens there.
00:05:14:04 (John Sheehan)
So, what are the main threats? What’s causing the declines?
00:05:18:04 (Dr. Megan Wallen)
There are several recognized threats to the Killer Whale population but there are three major ones that are widely accepted to be the primary factors affecting the recovery. The first is declining prey. So, both availability of prey and access to their preferred prey which is Chinook Salmon. The second is vessel impact to both physical and acoustic disturbance, which affects their ability to navigate, communicate with each other and also locate their prey. And the third primary threat is exposure to contaminants which they get primarily through consumption of contaminated prey. So, a lot of the contaminants that we see in Puget Sound like PCB’s and PBTE’s. Those build up in fat stores.
00:06:09:07 (John Sheehan)
In case you missed that or had to look it up like I did; Doctor Wallen just referred to Polychlorinated Biphenol’s and Polybrominated Diphenol Ethers. Those are chemicals used in all sorts of manufacturing and found in a lot of plastics and insulations.
00:06:24:08 (Dr. Megan Wallen)
And with Chinook Salmon being a particularly fatty fish that means the Killer Whales have an especially contaminated diet. It’s important to point out that these threats don’t act in isolation either. They’re all inner-connected and they can compound each other to have an even greater impact on the whales. So, that gives us even kind of more a sense of urgency to do what we can for their protection.
00:06:49:08 (John Sheehan)
And so, the threat of contamination is to…is it to the whales? Or is it to the food that they’re eating?
00:06:58:03 (Dr. Megan Wallen)

It’s both. So, the salmon are being affected by the contaminants but then when the Killer Whales eat the salmon those contaminants also build up in their blubber stores. There was a study several years ago. It was by Jessica London and researchers at the Northwest Fisheries Science Center and the Alaska Fisheries Science Center found that in years of low Chinook Salmon abundance the Killer Whales had higher levels of circulating contaminants. And so, you know the impact of low prey is compounding the affect of the contaminants. And that happens because when there isn’t enough food to eat whales are using their blubber stores. So, that is getting mobilized and so the contaminants are then circulating.
00:07:48:09 (John Sheehan)
So, are you saying that because they’re not eating as much, they have to use more of their Killer Whale fat and that’s got contaminants in it too and that’s creating more of a problem?
00:08:01:05 (Dr. Megan Wallen)

That’s right. Yeah so, when those contaminants are being circulated through the system that’s impacting all sorts of physiological functions. And in reproductive females those contaminants get offloaded to their calves through the milk. And so, young calves are also being impacted by these high contaminant levels.
00:08:23:09 (John Sheehan)
Yeah so, are the declines adults getting sick and dying? Or is it calves either not being born or dying too young?
00:08:35:00 (Dr. Megan Wallen)
Yeah, it’s still and open question and that’s something that a lot of researchers are still looking at. You know essentially is the lack of recovery due to survival or mortality or is it due to low reproduction? And there’s evidence pointing to the fact that it’s actually a low fecundity rate. So, low reproduction and survival of young calves that’s influencing the population size and the decline that we’re seeing.
00:09:04:09 (John Sheehan)
You mentioned the main threats of prey availability and human interaction and contamination of their environment. Is one the culprit or is it in that order of severity?
00:09:20:06 (Dr. Megan Wallen)
You know it’s a tough issue because there really is no silver bullet, especially because all of these impacts can compound each other. And so there’s really not one major threat that we can point to that’s causing the lack of recovery in this population. And so, we need to invest our resources from all angles to give the whales the best chance of recovering.
00:09:45:05 (John Sheehan)
Speaking of compounding problems; how is climate change or shifting ocean conditions affecting the population?
00:09:53:00 (Dr. Megan Wallen)
So, there’s no doubt that climate change is impacting the marine environment where the Southern Residents live. But it’s hard to pinpoint one specific aspect that’s impacting the whales directly. Although it almost certainly has played a role in the lack of recovery that we’ve seen in the population over the last fifteen years or so. But we can say that climate change is impacting the salmon populations that they feed on. For example, climate change affects both the sea surface and freshwater temperatures, stream flows, things that are really important for salmon spawning success and their survival. For example, warming water temperatures in the streams affect the out-migrating juvenile salmon in their survival. And plus, there are cumulative affects that are seen across the different life stages of salmon as they’re exposed to more stressors, being in both the fresh water and marine environments.
00:10:52:05 (John Sheehan)
And what’s the status of the Chinook Salmon population now?
00:10:57:04 (Dr. Megan Wallen)

Salmon in the Puget Sound and west coast wide are historical lows. In particular the Puget Sound Chinook Salmon stocks which are one of the preferred prey of Southern Residents; they themselves are listed as threatened under the Endangered Species Act. So, it’s a complicated issue where you have endangered predator feeding on you know a threatened species. And so, there’s extensive efforts coast wide to restore habitat and rebuild the salmon populations that are important not just for the Killer Whales but for the economy, for tribal culture, subsistence, and of course the marine and the river systems as a whole.
00:11:44:02 (John Sheehan)
What kind of role does hatchery salmon production play in helping the Killer Whales.
00:11:50:02 (Dr. Megan Wallen)

Hatchery production can help to boost the prey base for Southern Resident Killer Whales. So, the evidence tells us that the whales don’t discriminate between hatchery and wild fish. So, on a short term level it can help to get more fish out there and into the mouths of the whales. But extensive hatchery production can have long term impacts on the wild salmon populations. Which is why it’s important to focus on several different approaches such as ongoing habitat restoration efforts that help the salmon survive.
00:12:22:00 (John Sheehan)
Can you talk a little bit more about what ongoing efforts need to be taken?
00:12:26:01 (Dr. Megan Wallen)
So, we’re working to address those three primary threats in a variety of different ways. We are working to protect Southern Residents from vessel impacts through continued enforcement and education about the rules and guidelines for people that are operating vessels near the whales. There’s extensive efforts with habitat restoration that are important for salmon. We work with a lot of different partners; Washington State, Government of Canada, the tribes on all of these different threats. We’re also working with using drone footage to understand more about Killer Whale health and the seasonal changes in body condition. And so, the researchers can go out with drones and collect aerial images. And using a technique called photogrammetry they can actually document the size of the whale and see if it’s good or poor condition.
00:13:26:02 (John Sheehan)
So, in light of all the challenges what can we do? What can a citizen do?
00:13:33:03 (Dr. Megan Wallen)
Yeah, it’s important to be cognizant of the issues that are, that the Killer Whales are facing. You know if you’re out in the water make sure you’re aware of the guidelines and regulations for operating a vessel around Killer Whales. You know, be whale wise. When you’re out in the water give the whale space. It allows them to hunt and find the prey that they so desperately need. You know help out with your local salmon habitat restoration effort. And just generally be aware of a good environmental citizen.
00:14:06:00 (John Sheehan)
Doctor Megan Wallen, thanks so much for spending some time with us.
00:14:10:05 (Dr. Megan Wallen)

Thanks, I appreciate it.
00:14:12:00 (John Sheehan)
Doctor Megan Wallen is a marine mammal specialist in NOAA Fisheries West Coast Protected Resources Division and was the project lead on the five year review of the Southern Resident Killer Whale. The report was released in January. Special thanks to Marla Holt for providing the Killer Whale calls. On our next episode we’ll get back to our series exploring the different regions of NOAA Fisheries and how surveys are foundational to the work of science centers. I’m John Sheehan and this has been “Dive In with NOAA Fisheries.”
00:14:44:08 (AUDIO ENDS)
Google Search Result Description
Checking in on endangered Southern Resident Killer whales with NOAA Fisheries scientist Dr. Megan Wallen.