I have seen bioluminescence only once and it was honestly the most magical thing that I have ever seen.
It's a bucket list natural phenomenon every traveller would love to experience. Bioluminescent tides or sea sparkles are a rare and ethereal looking sight. And we're heading to the ocean to meet the strange species who use light to send signals through the dark. I'm Ranger Rosie Holdsworth. Welcome to Wild Tales, Bioluminescent Baywatch. You might have seen the pictures on Instagram of lagoons of electric blues and greens. People on the shore at night
splashing in waves that look lit up as if by magic. This natural phenomenon is called a bioluminescent tide. So, what causes the sea to light up in this eerie way? What's it like to experience it? And why is Bioluminescence itself found in so many mysterious ocean creatures? To find out, we need to go down to the ocean where it's... Dark at night or in deep deep waters where light shows up in the pitch black.
I'm Yasmin Meeda, I'm a marine biologist by training and I'm now working as a postdoctoral researcher at Cranfield University.
Dr Yasmin Meeda who goes by Yaz is not your typical marine biologist. You might imagine people in Yaz's profession out in research boats, studying dolphins, turtles, fish or other big fauna of the seas. But Yaz is interested in something different. She specialises in a branch of marine biology called microbiology.
I deal with all the tiny hidden wonders of the ocean that nobody really thinks about. It's often overlooked. I'm really interested in understanding how these microbial life actually sustain all the bigger species in the ocean that we know and love, like whales and sharks. But we really need to understand these tiny organisms.
Yaz is usually found in her white coat in her lab, pouring over the little guys, the weird and wonderful hidden microscopic organisms that don't get a lot of love, but they're essential for all ocean life. Yaz has another great passion, to make sure science is for everyone.
I'm really trying to champion the fact that science should be accessible to absolutely everyone. Myself, I actually failed my A-levels when I was at school. And then suddenly I really had a passion for science. And I believe that you don't have to have straight A's to actually get through and become a scientist.
Yaz's drive to open up science to more people led to her creating her Instagram account.
So I post on social media with a handle @marinebiologywithyaz. And it started just as showcasing to family and friends what I get up to. I mainly made this page to showcase the hidden wonders of the ocean.
As a marine biologist, Yaz knows all about bioluminescence. But she's only ever actually seen it once. And the experience has stayed with Yaz as one of the most memorable of her career.
I have seen bioluminescence. Only once. And it was honestly the most magical thing that I have ever seen. I'm an ambassador for the Marine Stewardship Council in the UK. We were fishing for sardines using ring net fishing. So this is a way to reduce bycatch so you're only fishing for what you want. I was fortunate enough to go out on a sardine fishing boat in Newlyn in Cornwall and I've never been on a fishing boat and as a marine biologist I'm always in the lab. I'm hardly ever out
at sea so this was a really new experience for me. So we set off at around 8pm in the evening. And I was told it should be quite calm. It should be OK. But we're going out at night and we'll be back early hours of the morning. So there's me, never been even fishing before. And so I'm now on this fishing vessel that we're going out. We're going out quite far into the ocean. And I'm like, wow, there's nothing around me. It's pitch black. I could see the stars. I could see the milky way.
I've never even seen that so vivid because obviously with light pollution, you can't see it. And as we were fishing, once they'd deployed the net, this is when I saw so many birds just coming down. And there were loads of seabirds, some seagulls, other species of birds I didn't even know. And it was so loud. The noise was just immense. And then as I was looking at these birds, I could see that they had these specks or these sparkles of a greeny blue hue. And I was like, this looks interesting.
And then one of the fishermen was like, it's the phosphorus. It's the phosphorus.
Phosphorus is a chemical element that can sometimes glow in the dark. But Yaz knows what they're seeing is something different.
And I was like, what are you on about? And they were like, that's what we call it, the phosphorus. And I was like, no, I think that's bioluminescence. And they were like, oh, is that what it's called? And I said, yeah, I've never seen it in real life. I've only ever seen videos. The colour was definitely like a bluey-green. You only see bioluminescence when there's movement in the water.
So as the waves are crashing and the birds are diving into the water, you then get this kind of different shades of this bioluminescence coming up and it's brighter in some areas and it's dimmer in others. And honestly it was just like an alien world to me because we were the only vessel I could see for a while. We were in the middle of the ocean I couldn't even see land and yet all around me were just these birds and bioluminescence and it was incredible.
ROSIE HOLDSWORTH: ROSIE HOLDSWORTH: Bioluminescent tides occur all around the world and some of the best known spots include beaches in Australia, Thailand, Puerto Rico and California. These sea sparkles also appear here in the UK. Wales has some of the most famous bioluminescent tides and it's found in other places too, like Yaz's experience in Cornwall. What you see in photos and videos can look a little different to with the naked eye, though no less magical to witness.
But I think what people see on photos or on documentaries can be slightly over-exaggerated. This is a little bit similar to my experience with the northern lights. I think your camera can really overexpose the green hue. You could definitely see it. And it was more like a, almost a neon green.
We know bioluminescent tides look magical, but what exactly is happening? Bioluminescence, when an organism lights up from inside its body through a chemical reaction, is found in nature in certain species. In the case of tides like those Yaz saw, these are caused by a type of algae called dinoflagellates. In these dinoflagellates, bioluminescent light is created when two chemicals, luciferin and luciferase, interact with
oxygen. This chemical reaction is triggered when water containing the dinoflagellates is disturbed, like when waves crash on the shore or when birds dive into the sea to catch fish.
Bioluminescence happens in loads of different organisms but in the ocean it is typically from dinoflagellates which are a group of phytoplankton and they are microscopic so you can't see them with the naked eye you'd need a microscope to see them normally. But when they create this bioluminescence you can see it as light and that's because there are thousands of them so collectively you'll be able to see this light. ROSIE HOLDSWORTH: ROSIE HOLDSWORTH: Bioluminescent
light isn't just found in these tiny dinoflagellates. It's found in lots of species, occasionally on land but by far most widespread in the ocean. Fireflies are a really good example of bioluminescence and so they cause bioluminescence within themselves but I've never actually seen fireflies myself. The anglerfish that are found in the deep sea, I want to say ugly but maybe that's unfair. They're the ones that if you've seen Finding Nemo, it's got the big light on the end of its head.
And the bacteria that are within these anglerfish are responsible for the Bioluminescence that you see. So that's how they can see in the dark when they're in the really deep sea. For different species, there could be different reasons as to why they have bioluminescence. Sometimes it could be because of mating. So it could attract a mate. Or for the case of dinoflagellates in the ocean, it could be to deter a predator.
And then that will deter the predator because they'll think, oh, there's something there and it will scare them off, which I think is pretty cool.
And perhaps the most mysterious is the centuries-old story of milky seas. Sailors talked of an eerie phenomenon of looking out to the ocean at night and seeing it transformed, as if blowing ghostly white all the way to the horizon. In the 1990s, scientists looking at satellite images finally confirmed these milky seas were a type of Bioluminescence, this time caused by bacteria, and that the light could be seen all the way from space.
Bioluminescent tides like in Yaz's story are relatively rare but they occur often enough for you to have a chance of witnessing them. So what are the top tips for seeing them for yourself?
My top tips if you want to see bioluminescence would definitely be to look out on the coast. There are certain areas within the UK that you could see it such as in Wales I'd definitely say Cornwall is a really good spot. My experience was not from the shore so I don't know how prominent it will be if you're just watching from a beach and
want to go and hunt for it. But if you can get on a boat and go and explore I think definitely looking at either Facebook groups or looking online at different travel blogs or Instagram or TikTok I think you could definitely find it and spot it from there.
I've seen bioluminescence myself just one time, on land. In glowworms' shining green bums in Leeds. It was really, really magical. But I've never seen bioluminescent tides in the ocean. They're really high on my bucket list. The fact this phenomenon even exists reminds us that our world is still so full of mystery and wonder.
I think the fact that bioluminescence is really unique is something that I think is quite alien to the world. And for me, I think that's one of the most amazing things about evolution and just the natural world, is that these things have just sprung up in nature based on either it could attract a mate, it could deter predators. And so I just think it's absolutely incredible that different organisms have such different traits that help them survive in our planet.
If you'd like to look for bioluminescence for yourself, do search for groups dedicated to spotting it along the Welsh coast and other parts of the UK. Just please don't do anything daft and follow safety advice when you're mixing with water, tides and the dark. Summer is a great time to see the UK's glowworms. You can find out more about them in our episode show notes. Until next time, follow Wild Tales on your podcast app. Find us on Instagram @wildtalesnt. And share your stories with us with
#wildtaleswednesday. See you next time.