Billions Of Sea Creatures, Lost To Heat Waves

IRA FLATOW: This is Science Friday. I’m Ira Flatow. You’ve all watched news footage of folks in the Pacific Northwest suffering and dying during record triple-digit heat they’ve never seen before. But there is also another climate tragedy– the devastation of the coastal wildlife. Estimates that over a billion sea creatures have died. We’re talking starfish, mussels, oysters, clams, barnacles, sea snails– all of these animals and more virtually baked to death on the beach, as they sat helpless in the scorching heat during low tide. Here to talk about what this means for the future of life along the coastline is someone who witnessed the die-off firsthand. Chris Harley, professor in the department of zoology at the University of British Columbia in Vancouver. Welcome to Science Friday.

CHRIS HARLEY: Thank you for having me.

IRA FLATOW: Tell us what you saw on the beach. Was it Kitsilano Beach in Vancouver?

CHRIS HARLEY: Kitsilano is the neighborhood where I live, and so I went down to my local beach on the middle day of the heat wave, just out of curiosity to see if anything interesting was happening. And before I saw anything, I smelled it. And it was the smell of death, and that was a very bad sign. That was the consistent comment from people that have lived here for decades is, I’ve never smelled anything like that before. And a friend of mine called it the new smell of climate change. And then going to other beaches on the following day, I realized the extent of the die-off. It was unprecedented, in my experience. It was just dead mussel after dead mussel, for kilometers.

IRA FLATOW: So as a scientist, how do you rationalize what you just saw and what you experienced?

CHRIS HARLEY: I feel like, when you go through the stages of grief, you also go through stages of scientific excitement. And the first was, oh, I’m going to learn something from this. And then it became much more depressing and sobering when I realized, well, I– there’s only so much I can learn from things that are already dead. I came to measure how hot they were getting, and I can’t because they’ve already died. And I’m worried because the magnitude of this die-off was more than I expected to be possible in Vancouver. And so we haven’t even started asking the right questions about what the implications might be, because we just weren’t expecting something to be this bad here.

IRA FLATOW: Because that’s your specialty, right? You’re a scientist who studies climate change and its impact on ecosystems. Was this killer heat wave something that your research had predicted?

CHRIS HARLEY: Well, maybe for the year 2080 or 2050. And we were trying to simulate warming like this in the field as creatively as possible, including using propane-powered turkey fryers to heat up tide pools and things like that. But it turns out that, in our experiments, we weren’t getting things hot enough to simulate this actual event that’s happening now. And we were trying to simulate something that wouldn’t happen for 30 or 50 years.

IRA FLATOW: Boy, that must have been surprising.

CHRIS HARLEY: It was very surprising.

IRA FLATOW: So what’s different about this happening in British Columbia versus, say, Louisiana or other coastal areas that are heating up as well? I mean, we’re seeing a lot of extreme heat events everywhere, but this one seems particularly striking.

CHRIS HARLEY: The ecosystems is in any given place are tuned, to a degree, to the temperatures that are– you might consider normal, over the past several decades or even thousands of years. And so getting a few degrees hotter in Louisiana might be just as bad as getting a few degrees hotter in British Columbia. This particular heat dome was many degrees hotter than the normal conditions, and just being out on the shore that day and sweating so profusely and worrying about heat stroke, it reminded me of being in Baja, Mexico, in August. It’s not the kind of thing that I was expecting in Canada.

IRA FLATOW: Have any scientists in your experience, your lifetime, ever experienced this kind of die-off on the beach in Vancouver?

CHRIS HARLEY: There have been a few small ones. There have been a few in other places in the world like California and New Zealand. And I don’t want to trivialize those. Those killed a lot of mussels and other things. But this one, in my 25 years of experience, is the most extensive die-off of intertidal life in response to a high temperature event that I’ve ever seen.

IRA FLATOW: So what are you estimating the British Columbia shoreline looks like down the road if such heat events continue?

CHRIS HARLEY: I think it’s going to end up looking like a strange combination of British Columbia, Southern California or Mexico, and Hong Kong. Places around Vancouver are just naturally a little bit warmer, and to find species that can handle temperatures warmer than they are now, you have to go very far south or to other parts of the world to find those species. And the ones from Mexico may or may not be able to migrate here on their own. Ones from Asia are arriving accidentally by ship, and those might be the ones that start to take over. So instead of seeing mussel beds, we might start seeing oyster beds. Instead of seeing kelps, we might start seeing some of the non-native seaweed. So a big ecosystem shift is already underway, and I think it’s only accelerating.

IRA FLATOW: And not only an ecosystem shift, but what comes with it, which might be an employment shift. If these animals are no longer able to survive, the fishing industry may have to change too, right?

CHRIS HARLEY: Yes. And we don’t know what the impacts on salmon might be. They likely suffered in the streams where the little juvenile fish are. They use a lot of things like mussels and seaweeds that have died as cover as they migrate out to sea. The shellfish growers are concerned about this, and they’re no dummies. They keep careful track of mortality events on their beaches, and they’re out looking now to see how bad it was. And we’re waiting to see what the implications are for that industry.

IRA FLATOW: Since scientists like yourselves have been caught surprised by this event, do you anticipate having to change the direction of your own work?

CHRIS HARLEY: Yes, and as luck would have it, I’m writing my five-year operating grant this fall. And I am changing what the topic is going to be. We’ve been working on warming as a problem, but we had underestimated the magnitude, how soon these events would arrive. So now we’re starting to think, well, all right, what happens if you get two in a row? Is that like getting two sunburns in a row, that’s much worse than just getting one? There’s a lot that we don’t understand about these extreme events.

IRA FLATOW: Speaking of this extreme event, what is the take-home message from this?

CHRIS HARLEY: I think there’s a few. One is, and I forgive people if they don’t care deeply about the plight of the barnacle, but the fact that we lost a lot of marine life, and the cherry growers had their fruit cooking on the trees, and wildfires are much worse than they had been, and people are dying in their homes because there’s insufficient cooling– all of these things point in the same direction. So I hope it is a call-to-action for even just little changes that we can make. We all stood up in the face of the COVID pandemic and made little changes, and that really helped. We can do the exact same thing with climate change, with small changes done by enough people.

IRA FLATOW: Well, I hope everybody is paying attention, and I thank you for what you do and for alerting us to this danger. So sorry to hear about what’s going on where you live. Chris Harley, professor in the department of zoology at the University of British Columbia in Vancouver. Thank you for taking time to be with us today.

CHRIS HARLEY: Thank you.

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