The Current - Bioluminescence: The secret language of light

Episode Date: September 10, 2025

She was the first marine biologist  to film a giant squid in its habitat. . Edie Widder is a pioneering marine biologist who believes the light in the dark ocean may actually be a form of communication.  She has dedicated her life to understanding the phenomenon known as bioluminescence. And she is one of the few people in the world who has been to the deepest 'twilight zone' of the ocean using tiny submersibles. Matt talks to Widder about her quest to capture the bioluminescence on video along with Tasha Van Zandt, director of a new documentary about Widder's life and work. A Life Illuminated is screening as part of the Toronto International Film Festival.

Every writer has a beginning. For Arundati Roy, it was her mother. In Mother Mary comes to me, the Booker Prize-winning author of the God of Small Things offers an intimate and inspiring account of how she became the person and writer she is, shaped by her complex relationship to the mother she describes as, My Shelter and My Storm. This is not just a memoir. It is a love story, a reckoning, and a journey into the making of one of the world's most celebrated voices.

Mother Mary comes to me by Arundati Roy. Now, wherever books are sold. This ad is brought to you by Simon and Schuster, Canada. This is a CBC podcast. Hello, I'm Matt Galloway, and this is the current podcast. What is that? Steve. Oh, my God. Oh, my God.

Okay, so this is... Oh, my God. Oh, my God. Oh, my God. Look at that boy. Why is everybody so excited? That was the moment that scientists saw something no one had ever seen before. A giant squid in its natural habitat.

What made that possible was Edie Witter, her fascination with technology and a natural phenomenon known as bioluminescence. Edie Witter is a pioneering marine biologist, explorer and inventor, and the subject of a new documentary that is screening as part of the Toronto International Film Festival. It's called A Life Illuminated. Edie Witter is with me in studio, along with the film's director, Tasha Van Zand. Good morning. Good morning. So watching that scene, and you can hear that in that little clip, you are over the moon excited by what you're seeing.

Insane. We were losing our minds. Why were you losing your minds? Because it's been kind of this great white whale for the community for a long time. The giant squid was well known. and there'd been many, many expeditions to go and try and film it and never succeeded. And to finally do it was a big deal. What did you actually see?

Just describe what it looked like? So the first time we saw it, it just came in from the side of the camera system that I developed and so kind of waved its arms in front of the camera lens. And it was enormous and bigger than we were expecting. So the next time we deployed the camera, we extended the optical lure that I was using to try to try to, attract the giant squid further away from the camera so we have a better chance of seeing it. So we saw it several times where it just felt like it was doing a fan dance, just tempting us, but never quite showing itself.

And then finally on this one deployment, it came in from a distance. And you saw it swim straight towards the camera and then spread its arms wide and actually just engulfed the camera. It was amazing. I mean, the obvious question is how big is the giant squid? It is enormous. It is enormous. So that one, if it's head ahead, its tentacles fully extended,

would have been as tall as a two-story building. What? Yeah. What was it like for you, Tasha, to see these images? Well, for me, you know, I first learned of Edy from the giant's good footage in 2012, along with the rest of the world. And it really just changed my perspective to learn that there's this creature on our ocean planet that large that hadn't been discovered till now.

And that really drew me to Edie to learn more about the person behind that image who had spent her life, finding new ways to be able to reveal these unseen worlds. The reason that you were able to capture these images is because of your obsession, fascination, devotion to studying bioluminescence. Do you just describe what that is for people who don't know? So people know about bioluminescence through fireflies, and there are a few other land animals that can make lights, some earthworms and millipedes and send. but it's rare on land. In the ocean, it's the rule rather than the exception. Approximately 75% of the animals in the open ocean environment make light, and they use it to find food to attract mates to defend against predators. And so a lot of my career, I've been trying to learn what that language is about. And in the process, discovered this one display that seemed to be very attractive

to large predators. And so it was that display that we used to draw in the giant squid. Do we know how they create the light? Yes, we do. So it's a chemical reaction. Chemicals are called luciferin for the substrate and luciferase for the enzyme. But those are just generic terms. There's actually different chemicals and different animals. It's apparently evolved many different times in evolutionary history.

It's a clear indication of the survival value of a trait when you see that kind of degree of convergent evolution. How do you survive in the dark? Make light. And so you talked about with the giant squid that you had a lure? Yes. Explain, and we see this in the film. Explain what you did to try to lure this thing that people had never seen before to your camera. So in my effort to understand how to, how this language of light works,

I created this optical lure that could imitate certain types of bioluminescent displays. And one of them was a jellyfish that would produce this pinwheel of light, just an amazing display, that seemed to be an attractant. And the theory was that it was what's called a burglar alarm. So it's the same reason you have flashing lights and beeping horns on your car alarm system. It's meant to attract attention and hopefully scare away the burglar or bring in the police to take the burglar away. And so an animal that can make light will use every light organ it's got if it's caught in the clutches of a predator to attract attention from something bigger that may then attack what's attacking them and afford them an opportunity for escape.

So the very first time I tried that burglar alarm on this camera system I've been developed. thing called the eye in the sea. The first time we turned on that optical lure pinwheel display, 86 seconds after we turned it on for the first time, we recorded a squid over six feet long that was completely new to science. It could not even be placed in any known scientific family. And it's just so clear to me that we've been scaring the animals away. We go down with these bright lights and noisy thrusters and in a world that's dark and quiet and expect the animals to hang around? You've used this phrase a couple of times, and it comes up in the film a lot, the language of light. Tell me about what that phrase means to you. You're communicating.

Animals are communicating with each other. So the best examples that are clearest to us are things that are sexual displays. So a firefly flash pattern is a communication of what species I am and what sex I am in order to attract a mate. And there's a lot of animals in the ocean that can do that with different flash patterns or different shaped light organs, some very elaborate displays that are sexual displays. But then some of them are used for defense. So they'll display a pattern that is intended to indicate, don't eat me or you'll be sorry, because I'm toxic. You said this is the rule, not the exception in the ocean. Yes. So the first time you saw this, describe what that was like. So I was diving in a single person submersible. It was a diving suit called Wasp. And

Which looks terrifying from, I'm not the diver, but I was like, there's no way that I would go in that kind of thing, because it's very confined. It's very confined. It's actually very uncomfortable. I tell people that diving and wasp changed my understanding of nature of life in the ocean, but it also changed my understanding of the expression colder than a witch's tit because it's brutally cold down there. but it was an incredible experience to go down and turn out the lights and just be surrounded by this incredible display of light everywhere around me there were things flashing and glowing and squirting and it was all different colors of blue it was astonishing and I knew how much energy it took for life to make light and I felt like this has got to be one of the most important processes in the ocean why aren't more people studying it but the sense was that we had been missing this to your point because people have been going down, as you said,

with thrusters and bright lights and you're scaring everything away. Yeah, and it was only the people that went in submersibles that got to see it because we had no way to record it. There were no cameras sensitive enough to record it. So it was a very small audience. This film, it sends you down into the sea to capture this flashback phenomenon. What is that? So that's something that I've seen through much of my career. So most of the time, you have to have to be. You have to to stimulate bioluminescence in some way. The animals conserve it. They don't use it willy-nilly. And they need to be mechanically stimulated. Usually you bump them. That's the most common form of stimulus. But there's another way you can stimulate some of them, and that's

with light. You flash a light, and they flash back. And the flashback phenomenon is this thing where you flash out into the water around you in the submersible, and you're just completely surrounded by a galaxy of light flashing back. in unison at you. And I've seen it so many times and tried so many times to record it, but always with cameras that weren't adequate or light stimuli that weren't adequate, there were just always some kind of obstacle. And for this expedition, we were hoping to film it, but we had very short period of time. That wasn't exaggeration at all. We were right down to the last day, and we recorded it for the very first time. It's a very, very, very, very

big deal as far as I'm concerned. You're off the coast of Portugal, right? Is that where you're? Yeah, we were in the Azores. And you go down in these little submersibles. Just describe, I mean, it's not the suit. It seems a bit more luxurious or spacious, but it may be a bit more comfortable. It's tremendously luxurious as far as I'm concerned. It's like a fish bowl. You're inside this glass sphere, but the fish are on the outside and the people are on the inside. Describe what that as like when you go into that world. Or you should ask, Tasha because she actually went down in a submersible to film this, and she'd never been in a submersible before in her life. So she has that amazing experience of the first time of

seeing it. Okay. Well, come back to you. Okay. You might have, I mean, maybe you've seen it before, but Tasha goes into this to film, what was that like? Had you ever done anything at this before? No. Any diving or anything like that? Never before. I've always been fascinated with our ocean world and spending time in the ocean, but I had never dove, let alone to 3,300 feet. But Eadie was our guide, and for me I had spent so many years asking Eidie this very question, what it feels like to go down, and hearing her incredible descriptions of what that feels like. And then to be able to go down next to Eadie on one of our first dives and experience this world with her, it was just transformative.

It really feels like you're going to another planet. And when you recognize that it is within our own pale blue dot and most of our pale blue dot, it really shifted my perspective of our world that we live in. I think a lot about how when we were on this dive, I was thinking of astronauts going to space and describing the overview effect, where they look down at Earth and see how small and interconnected we are. But when we were down there in the submersible and landing on the bottom of the ocean at 3,300 feet, I felt that same feeling, but that we were inside of the earth and that this is our ocean planet, you know, 99.5% of the living space on our planet is ocean. And here we are inside of it, kind of at the core of this planet we all share, and yet we know nothing about it. And so that was really just mind-blowingly awesome and completely, completely transformative to be able to experience with Edie. Every writer has a beginning. For Arundati Roy, it was her mother.

In Mother Mary comes to me, the Booker Prize-winning author of the God of Small Things offers an intimate and inspiring account of how she became the person and writer she is, shaped by her complex relationship to the mother she describes as, my shelter and my storm. This is not just a memoir. It is a love story, a reckoning, and a journey into the making of one of the world's most celebrated voices. Mother Mary comes to me by Arundati Roy. Available now, wherever books are sold. This ad is brought to you by Simon & Schuster, Canada.

There are two kinds of Canadians, those who feel something when they hear this music. And those who've been missing out so far. I'm Chris Howdy. And I'm Neil Kuxel. We are the co-hosts of As It Happens. And every day we speak with people at the center of the day's most hard-hitting, heartbreaking, and sometimes hilarious news stories.

Also, we have puns. Here why, as it happens, is one of Canada's longest running in most beloved shows. You can find us wherever you get your podcasts. Did you agree immediately that this was something that you would do? I'm sure there's risk. Did you say, yeah, absolutely. I'm in there 100% or did you need to be convinced? Did you have to twist your arm to get in the subversible?

Well, you know, I've been fascinated with Edie's stories for so long, and hearing Edie's passion and love for diving and submersibles helped me to overcome my fears. You know, I had a lot of conversations with Edie about how do you prepare for something like this, just mentally to go on a dive to those depths. And, you know, she shared often that there is no real way you can prepare until you're there. It's such a different world that you're entering into. but her message that curiosity can overcome fear became my mantra and there were moments where I had nerves you know you go out on a ship into the sea you have a tether at first and they detach it and then all of a sudden you're starting to submerge under the surface and you're seeing the water fill up outside of the sub and you're going into this different world and as edie says

in the film, it is a world of gradients. You know, when you first go into the sunlit zone, you see that snow's window get smaller and smaller and the light go dimmer and dimmer. Then all of the sudden, you're in this turquoise blue, incredible world. And as you descend down into the twilight zone, everything goes dark. And all of a sudden, you're in complete darkness. And as we reach that level, that's when we started to see the bioluminescence. And little sparks and embers of bioluminescence shooting out of the thrusters as we would go through the darkness into the deep. What's the twilight zone? The twilight zone is between 200 meters and a thousand meters. So below 200 meters, the light level is insufficient for photosynthesis, but it's still

sufficient for vision. And so animals can still see sunlight in the ocean between 200 and 1,000 meters. And then below that is perpetual darkness except for the bioluminescence. But the drivers for vision are so strong that even though this is a world so much without sunlight, most of the animals have eyes. And even in places where sunlight can't penetrate, they have eyes to see bioluminescence. One of the things that's amazing about this film, I don't know how many dives you've done. Hundreds. You still have this extraordinary sense of like wonder and joy when you're down there. Like, it's like you're going, not for the first time, because you're an expert, but you're seeing things in some ways.

There's that idea of a beginner's mind, that you're seeing things with a beginner's mind. Do you know what I mean? Absolutely, because it is, I am still a beginner. Every time I dive, I have the opportunity to see something nobody's ever seen before. And what a thrill that is. That's just incredible. I never grow tired of it. The other part of it is that we have this idea that down in those depths, it's just nothingness.

And that's not the case at all, right? Especially if you look for the bioluminescence because it can look like there's not much out there except particles of marine snow. And then you do the flashback and you realize you're surrounded by life. That's a big deal. How did you shoot this? I mean, aside from being there in the submersible, how did you capture what I have seen on this film? Well, that was definitely an expedition in and of itself. I worked alongside my producer and cinematographer Sebastian Zek and Edie, of course, to really come up with a plan of how we're going to document in such a small window of time, something Edie's been looking for her entire life.

And so that was a huge challenge. So we had one sub, that was the science sub, Edie's sub, where she was able to dive and do her research, and one sub that was the media sub. So we were able to film all of the external shots that you see of the submersible going down into the depths in the film. And that was so important to us to be able to show that scale and what that looks like to be this small little submersible in this vast, vast ocean. But then additionally to film in darkness is a huge challenge that Edie has been pioneering her entire life. And we are right now just on the cusp of being able to really capture what's there. And even still, what we were able to document in this film, there was so much with our naked human eye that we saw that just couldn't quite translate. So we used very, very, very sensitive low-light cameras.

You know, Sebastian was rigging cameras within the sub and microphones and just hoping and hoping and crossing our fingers that when they come back up, that we would have the footage to encapsulate that experience of theirs because there is no way to stop in. change battery and make any fixes, you know, this was kind of our one shot to document that dive for E.D. You say in the film, part of this is about your own life story as well, that your mission was to not lead an ordinary life. What did that mean? When I was a kid and daydreaming, I think, like most kids, I wanted to be a superhero. I wanted to be a female version of Zorro. But, I mean, I just wanted to have an interesting life.

and I think my younger self would be proud of how things turned out. What happened? You went to Fiji. What happened when you went to Fiji for the first time? Well, that year, when I was 11, we traveled the whole year, and I felt like it woke me up. I think I'd been daydreaming through my life up until that point. And there were so many things I saw during those travels. So we traveled through Europe and saw a great art, and I wanted to be an artist in Egypt and saw the pyramids, and I wanted to be an archaeologist. and so on and so forth, got to Australia, and I decided I wanted to be a biologist. And our last stop was Fiji, and I got to explore a coral reef and decided I wanted to be a marine biologist. So the family joke is if we had traveled from west to east, instead of east

to west, I might have ended up an artist. But I think that's probably unlikely. But there had to be something when you were there looking under the surface of the ocean, and you saw that coral reef that did something to you. It was the awesomeness of life everywhere, just bursting forth, every little. pool that you look in in that coral reef there would be a blue star why is that starfish blue and just giant clams that big enough to swallow me and iridescence and bandaged shrimp i mean it was insane i wanted to know it all what is this all about how difficult was it to get to where you are now in part because you say in the film that women were believed to be bad luck at sea

oh yeah sailors are very superstitious and so So when you would come in and say, listen, this is what I want to do. This is what I know that I can achieve. Oh, good Lord. I never said that in those first days. You just try to blend it in the background and do your job as best you can. But, no, it was a struggle. But, you know, you learn to overcome.

So in those days, for example, we didn't manufacture our water at sea. You had to bring all potable water you were going to need. And so if they ran out of water, the expedition was over. And if there was a woman on board, the woman would get blamed for taking Hollywood showers. So I was very proud of the fact that I could take a shower in less than two gallons of water. And people can hear on a ship how much water are you using, so it was important. First time I went out on a British ship, I was off the northwest coast of Africa, and it was a month-long expedition. They told me that because I was on board, they had put on an extra 10,000 gallons of water.

I went kind of ballistic. But they had the data to back it up. Turns out when there's a woman on board, the men take more showers. So I was responsible for better hygiene. You said that your role model, people now look at you as a role model, but your role model was your mom. Absolutely. Who was from Saskatchewan, we're proud to say. Tell me a little bit about why she was your role model.

My mom grew up on a farm. She spent all of her youth going back and forth to school with a horse and buggy. she could handle a team of four pulling a combine and she went on to get a PhD in mathematics from Brynmar College so you couldn't tell me that a woman couldn't do something I mean she was just my role model she was my hero do you ever think of how dangerous the work is that you do I mean there have been stories and people

this comes up in the film where you have a scary incident where your submersible starts to leak and people wonder what's going to go on it only gets to a certain point and doesn't leak more. Oh, no, it was leaking the whole time. It was leaking the whole time. Yeah, but I fortunately still had just enough ballast to overcome it. So I blew ballast and jammed on my vertical thrusters, and I was very close to the tipping point of not being able to get back up,

but I did get back up and they were able to pull me out. So, yeah, you think about those issues. You have to think about them. There's risk factors, but there's risk factors every time you get in a car. I think my husband has said on several occasions, he feels safer about me going out and diving in submersibles and driving on the highway because I've got a whole team looking out for me when I'm on a ship. But, you know, when we were preparing for that expedition, it was right after Ocean Gate. So there was a lot of concern in the community as a whole that... This is the Titan submersible?

Yeah. What was the concern? That we not use a submersible that we weren't comfortable with. And so there were a couple of things that we were considering when Tasha was wanting to film this. And one of them that we just decided it wasn't safe enough. And so we thought we were out of luck at that point because we didn't have any other options. And that's when Ocean X stepped in and saved us. How has being part of this changed how you think about the ocean?

It's completely transformed how I think about the ocean. You know, I never knew this life existed in this way in our oceans until I met. Edie. I had read about bioluminescence. I grew up with, you know, stories from Jacques Cousteau. But when I met Edie, I realized that there's a whole on-scene world that we just haven't been looking for in the right way. And that's a huge perspective shift to think about how are we looking at our planet? What other wonders and mysteries could be there that we just haven't learned to look for yet? And that gives me a lot of hope. There's this obsession with space travel. And again, in the film, you kind of talk about how we've explored, what, 0.05%

of the bottom of the ocean, and yet we're very keen on getting off the planet and getting out into space. What are we missing? Well, I think it comes from this natural driver to be explorers. That's who we are. That's how we've learned to survive on this planet is as explorers. But a lot of the justification for space exploration is that we've finished exploring the planet. That's absurd. And also, you know, the notion that we can survive on another planet right now is equally absurd when we don't even know how to survive on this one, which is evolved to support us, but we're destroying those support systems.

And the biggest one of them all is the ocean. Do you miss being there in the ocean when you're here on land? I miss it, yes, to some extent. But then, of course, I miss my husband when I'm at sea. So it's a balance. When will you get back? I have no idea. If that ended up being the last dive of my career, that would be pretty okay.

Really? You'd be happy with that? Oh, I could definitely be happy with that. I feel just so fortunate with all the dives that I have had. Of course, I would want more, but I don't want to be greedy. It's an amazing, just the way that you changed to Tasha's point, the perspective on how we think of the earth, but also the things that you have seen and the sense of wonder and enthusiasm that you have still about them is incredible. Thank you very much for coming in and telling us about it.

Thank you. Edie Witter is a pioneering marine biologist, explorer and inventor. Tasha Van Zant is director of a new documentary about Edie's life and work. It's called A Life Illuminated. It is screening as part of the Toronto International Film Festival. You've been listening to the current podcast. My name is Matt Galloway. Thanks for listening.

I'll talk to you soon. For more CBC podcasts, go to CBC Podcasts, go to cbc.ca slash podcasts.