Think Out Loud

Climate change is making mass seabird die-offs more frequent along West Coast

By Sheraz Sadiq (OPB)
July 17, 2023 3:18 p.m. Updated: July 24, 2023 8:38 p.m.

Broadcast: Monday, July 17

FILE - Tufted puffins live most their lives at sea, only coming near the shore to nest on sea rocks during the summer mating season.

FILE - Tufted puffins live most their lives at sea, only coming near the shore to nest on sea rocks during the summer mating season.

Stephani Gordon


With its bright orange bill, white face and curling, yellow plumes, the tufted puffin is arguably the most recognizable seabird in Oregon. But scientists are now getting a clearer picture of how climate change is affecting the survival of tufted puffins and other seabirds.

A new study from the University of Washington found that persistent heat waves in the marine environment linked to climate change are leading to the deaths of hundreds of thousands of seabirds several months later. The researchers also found that these mass die-offs of seabirds used to happen once a decade, but are now happening more frequently, including five consecutive years, from 2014 to 2019, when millions of seabirds washed up on beaches stretching from California to Alaska. Julia Parrish is a marine biologist at the University of Washington and a co-author of the study which was published earlier this month. She joins us to talk about the findings.

Note: This transcript was computer generated and edited by a volunteer.

Dave Miller: From the Gert Boyle Studio at OPB, this is Think Out Loud. I’m Dave Miller. It is not unheard of for large numbers of seabirds to die-off and for their bodies to wash up on shore. These massive die-offs on the Pacific Coast used to happen every decade or so, but a new study from the University of Washington found that climate change is making these events much more likely. In fact, they happened in five consecutive years from 2014 to 2019: millions of dead birds washed up on beaches, stretching from California to Alaska. Julia Parrish is a marine biologist at the University of Washington and a co-author of this new study. She joins us now with more. Welcome to Think Out Loud.

Julia Parrish: Thanks, Dave. Thanks for inviting me.

Miller: Yeah, thanks for joining us. What exactly motivated this particular study?

Parrish: [Laughs] That’s a great question, right? It’s kind of morbid and geeky all at the same time, millions of dead birds washing up on beaches. The start of this study came many decades ago when I was wondering, as a seabird biologist, whether or not birds that wash ashore with the tide, who have died at sea, can tell us something about the health of the marine ecosystem, and it turns out they can. And that was the start of a Citizen Science Program called COASST, which you mentioned – The Coastal Observation and Seabird Survey Team.

COASST and I have grown up together over the last few decades involving, gosh, thousands of coastal residents in Oregon and also California and Washington and Alaska and going out monthly and just seeing what’s on local beaches and then rolling all that data up into larger scale science stories. And this is our latest one and also our largest one.

Miller: Am I right that part of what motivated this was that individual citizen scientists or beachcombers with training and some rigor attached to what they were paying attention to, they started noticing an increase in the number of die-off events?

Parrish: Actually, they certainly notice when there are die-off events because a beach that you walk once a month with your COASST partner, who might be your life partner, might be your kids or a coworker or a best female friend, family member, you notice when there’s a lot more carcasses out there and when that happens, of course, people call into us, but they also send us the data. But what’s more interesting to me is people noticed when there were fewer carcasses than normal. When there was a lull, a quiet winter, and no carcasses coming ashore – and that actually, was one tip off for us that started us down the rabbit hole of science, that ended in this paper. And that’s because…

Miller: …Why is it that an absence of what I would think of as bad news, would have been something that people would be so attuned to?

Parrish: Yeah. Well, that’s a great question. So people who go out on the beach, just like people who walk in a State Park or a National Park regularly, people who go up hiking on Mount Hood,  are going to notice where natural events happen, when and where the wild flowers are blooming. And if you’re on the beach you’re gonna notice what comes in on the tide when there’s kelp, rolled up on the beach when there are beach birds, when you might see marine mammals. So they get a sort of annual calendar or picture. Sometimes we call that an almanac, and they come to expect what they’re gonna see when, and when they don’t see it, then they wonder what’s going on.

So a lot of something can be bad, but the absence of something can also be bad. And in this particular case that’s because normally when we see carcasses floating ashore, they’re telling us that the system is actually in balance. For instance, after the breeding season, particularly in Northern Oregon and going down to Yaquina Head, we will see lots of Common murres. They’re sort of seabirds that look like they’re wearing a tuxedo. [They] come washing in and that’s because they’ve just finished breeding. And there’s lots and lots of murres breeding along the coast of Oregon, in fact, more than a million of them. And so there’s just lots of chicks in the water and there are lots of parents that pushed it a little too far. So, COASST-ers in Oregon come to expect murres washing in about August, September, on into October.

And if they don’t see them, they wonder, “Well, what’s going on?” Is that because the murres never came? Is that because the murres had a bad breeding season? So sometimes that staged mortality, a little bit of mortality, can actually signal to us, things are ok. Seems kind of strange, doesn’t it?

Miller: Well, until you explain it . . .but it’s a sobering fact that sometimes massive die-offs are a natural part of enormous ecosystem cycles. So what did you learn when you looked at this aggregated citizen-collected data spanning three decades?

Parrish: Well, one thing that we found, which we thought was the case, but this paper nails it - We found that when the surface of the ocean is warmer than normal, right? So we have the climatology or the long term normal of the sea surface temperature. And we keep that now by satellite. So we can tell when the ocean is warmer than normal, and how long that phenomena persists and how intense it is – is it just a degree above normal? Is it two, is it three? More than that? So when the sea surface temperature off our coast is persistently warm for about six months or more, and more than a degree above long term normal, we know now with certainty, that we’re gonna see a mass mortality event. So this is not just the normal mortality that we see after breeding, this is something that’s at least five times the maximum that we’ve seen, this goes from tens of thousands of birds stretched over the entire coastline of the Pacific Northwest to hundreds of thousands of birds. So that’s a big jump. That’s a big change.

What we know is that when the temperature goes up a degree or so above long term normal and stays that way, we call that a marine heat wave. And when it stays that way, we’re gonna get a big die off of birds about one to six months after that starts. And then we’re gonna get another one about 10 to 16 months later. So that’s already a year and a half long event. And then after that, we’re gonna get a lull. We’re gonna get no birds washing up. And that’s when we think the system is recuperating, building those populations that died in the first 16 months back. And that’s really interesting to us, that there’s a pattern that lasts almost three years, and it’s repeated over and over again when we have heating events.

Miller: What is your theory for the mechanism there, for what’s happening in both of those die offs? The initial one following the marine heat wave and then the second ripple that happens more than a year later?

Parrish: That’s a great term, “the second ripple,” I’m gonna steal that from you. Well, we think the first and second event are brought on by the same phenomenon – that is, a loss of food to these seabirds. So the first event is sometimes smaller seabirds, things that are eating small shrimp, things we call krill or even zooplankton, sort of the insects of the sea, things smaller than krill. And, so they’ll feel the effects of this bottom-up shift in the ecosystem, which is ultimately resulting in less food available to top predators in the system, including seabirds and marine mammals. And big fish like salmon or pollock or cod or halibut.

So, these marine heat waves that really change the coastal ecosystem, change the flow of energy through the ecosystem, have consequences, not just for seabirds, but for all top predators in the system.

Miller: So it sounds like what you’re talking about is mass starvation?


Parrish: I am. You got it. That’s exactly what I’m talking about.

Miller: And that’s the same reason, more than a year later?

Parrish: It takes a while to get up through the system. So the birds that are eating relatively low on the food chain are gonna experience that first. And the birds that are eating higher on the food chain, for instance, they’re feeding on small fish, they’re gonna feel that as a delayed onset. So that kind of one-two punch is, as you said, those ripples that are going through the system.

Miller: Are some species of seabirds particularly sensitive to increases in ocean temperature? I mean, have you noticed, when you look at all this data, that some species or families of species are more likely to die in the climate change induced marine heatwaves?

Parrish: Yeah, that’s a really astute question. We actually find that is true. So there’s a group of birds, very, very prevalent in Oregon called the Alcids [Alcidae]. Sometimes they’re referred to as the Auks. So let me give you some examples of members of that group, the Common murres are members of that group, so are Tufted puffins. So are Pigeon guillemots and Rhinoceros auklets and Cassin’s auklets. And then of course, the endangered Marbled murrelet is also part of that group.

We have certainly found, particularly in the lower 48, that when we see these marine heat waves that that group of birds, that family of birds appears to be the ones that are the most affected. What’s interesting about those birds is they’re all the deep diving birds so they can dive maybe a football field to several football fields. So anywhere on the coastal shelf that a big old king salmon, or silver salmon can go, these birds can go.

Miller: Some of these birds can dive 300 yards under the surface of the ocean?

Parrish: Isn’t that amazing?

Miller: It’s extraordinary…

Parrish: They are scrappy!

Miller: When I go four feet down, my head hurts.

We’ve been talking about the focus of your research, which is the Northwest Coast, the Pacific Coast, going down into California and going well up into Alaska. But obviously, this is just a part of global ocean warming. Is there data to support sort of similar findings in other coasts around the world?

Parrish: Oh, that is a great question. We do have a huge amount of data from the Pacific Northwest and Alaska. And that is in part because we have a set of citizen science programs now, COASST is one of them, but it’s not the only one. We have two sister programs, Beachcombers and Beach Watch, south of us in California. And then we have a sister program in British Columbia, called British Columbia Beach Bird Survey. So those four programs working together, collecting data in the same way, have a really good lock on what’s going on in the Pacific Northwest and Alaska. Elsewhere in the world, there are beach bird programs, but they’re not as large in space.

We know that in some other places in the world where you’ve got the intersection of super, super productive, cold coastal water with upwelling, like we have here in the Pacific Northwest, and lots of seabirds, that we do see this phenomena when there’s a marine heat wave that birds die off. So a good example of that is the coast of South America, particularly Peru. Different birds that nest there, but similar phenomena, that when the water warms for a long period of time, El Niño is their water warming phenomena. They’ll see die offs of both seabirds and marine mammals. So, echoing what we see here in the Pacific Northwest.

But they don’t have the citizen program on the beaches. So they’ve been unable to quantify that to the degree that we have. So we have both a phenomena, and we have a really robust citizen science program to go out and get those data. Because honestly, as a scientist, even at a university, I have no hope for collecting those data through normal mainstream science pathways. I rely on the coastal citizens in dozens of communities all up and down the coast to do that work. And to also just tell me what they see, beyond the data collection. They’re really my eyes and ears about what’s going on.

Miller: In the time that you’ve been doing your work, have you seen a change in the way that fellow scientists, people with PhDs and maybe a natural belief based on many, many years of education and training, that they know best, how to collect data and how to do science - Have you seen a change in, the way trained scientists think about citizen collected data?

Parrish: Yeah, I actually have, and it’s wonderful. So I think that the kind of work that I do, citizen science, where I’m developing a protocol, a way of collecting data, a set of directions and I’m going out in community and inviting people to trainings and training them up on doing that, I’m connecting to something they’re already doing. In this case, walking the beach. And that kind of data collection can be very, very powerful because everybody who is participating in the program is doing it the same way. And there are several examples of that, not only beach birds, all kinds of things: weather, extreme events, the amount of snow at altitude, the spring and fall migrations of songbirds, all sorts of different things have citizen science programs developed around them.

What we’re finding in mainstream science is that kind of data, where we have lots and lots and lots and lots of data points - I mean, currently, COASST has about 500 different beaches that are being monitored and that’s huge. So that level of data we can only get by partnering with people, right? We don’t tell them what to do, we partner with them because as much as they’re following our protocol, they’re also giving us their observations about other things that are going on and that really helps us understand the system. So it’s really a partnership between, in my case, coastal residents and scientists to figure out what’s the normal pattern, what are the changes from it? What’s creating those changes and what’s the future look like, given those changes are happening?

Miller: So, let’s turn back to that future, just before we say goodbye, because I guess I’m wondering to the extent that this is even knowable, now, how much these different bird populations are bouncing back from the increased die offs? And how much their populations could simply dwindle because they don’t have the numbers to actually come back from these declines?

Parrish: Yeah, you’ve hit the nub of it, right? That, that is the sobering question that is provoked by this study. And you started this segment by telling people that it used to be that we had a large mass mortality, our largest category, category four - think of that like a big, big hurricane, about once a decade. But now we’ve switched to one a year, 2014 through 2019, and that continues on in Alaska, up into 2021 and 2022. So when we see very large scale untoward mortality that’s happening so frequently, what that tells us, given what we now know about this double ripple plus a lull, it takes time for the system to reset itself. There’s not enough time.

So what we see the system doing now is just setting a lower bar if you will, for the number of seabirds that can be supported. And that means that we are going to see some losers in the system, some species where we’ll see far fewer than we saw, some species that won’t be able to hang on because they’re at low levels to begin with. I think we are facing a world with fewer seabirds and that means by extension, fewer other top predators as well, fewer marine mammals and quite possibly fewer commercially important fish.

Miller: Julia Parrish, thanks very much for joining us today. I appreciate it.

Parrish: Thanks, Dave.

Miller: Julia Parrish is a marine biologist at the University of Washington and a co-author of this new study about the increase in massive seabird die offs, an increase directly related to climate change.

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