“Life that Glows”: a breathtaking look at bioluminescent wildlife
By: Ashley Gustafson
Organisms that glow in the dark have long been celebrated for their fascinating beauty. The phenomenon of bioluminescence captures the imagination of people of all ages. From jellyfish to plankton, BBC’s new television program “Life that Glows”, voiced by veteran broadcaster Sir David Attenborough (even if you don’t know his name, you’ll know his voice, trust me), features some of the most beautiful, enthralling, and natural occurrences of bioluminescence around the world.
What is Bioluminescence and what makes it glow?
The existence or appearance of glowing organisms is all thanks to something in science called bioluminescence which put simply is the production and emission of light by a living organism. This light is produced by energy released from chemical reactions that occur within the organism that glows. The best and most singularly understood example of an organism that is bioluminescent is the firefly. While we all grow up with the firefly as an example, bioluminescence is found in a surprising range of fauna from beetles to fungi. Many organisms that use bioluminescence do so at levels so low that our eyes, or cameras for that matter, aren’t sensitive enough to capture it. In fact, this documentary wouldn’t have been possible 15 years ago because technology wasn’t capable of capturing such sensitive material. Thanks to this new technology, scientists are uncovering more and more bioluminescent organisms than ever before.
Glowing mysteries uncovered
Many of the organisms that appear glowing in the film weren’t necessarily organisms you’d expect to be glowing or weren’t believed to have that ability. While the purpose of bioluminescence is not completely understood it typically interpreted as a way to warn or evade predators. Also, it has been seen in deep ocean organisms as a way to lure and detect prey. It may also be a way for animals of the same species to communicate with each other. This could be for a wide variety of purposes from reproduction to organized defense.
However, some of the organisms featured in this program don’t quite fit this current model of thinking. One example from the film is the glowing earth worms. Earth worms live underground with no eyesight and there are no predators they are warding off, so why are they glowing on screen? Sir David poses this question to BBC Wildlife by stating, “It’s well-known that there is a gene for luminosity. It occurs in early invertebrates. It’s in plankton, dinoflagellates in the sea, earthworms, fungi. So it leads you to suppose that the gene for luminosity must have occurred right at the basis of evolution, in a very early period.” This discovery and general idea of thinking suggests that prehistoric oceans may have been full of glowing organisms that eventually passed the gene on generations as life moved from sea to land.
Glowing organisms and luminosity are already heavily associated with the world’s oceans. Normally, the first organisms people think of are jellyfish. I know personally, nearly every jellyfish exhibit I have visited at zoos and aquariums features glowing bubble tanks with ethereal jellies throughout. And yes, this documentary also features beautiful arrays of glowing jelly fish but perhaps the most stunning imagery from the whole feature (I may be biased) is watching dolphins swim in glow-in-the-dark waters.
Already gorgeous, dolphins are naturally some of the ocean’s most gregarious, intelligent, and popular animals. Watching dolphins swim through water on any average day is already a beautiful and delightful experience in its own right, but watching dolphins swim at night time in the ocean with millions of luminous plankton around them is something else. When the dolphins swim through the area where the dinoflagellates or plankton are, they become agitated and glow creating the appearance of glowing dolphins. With just moon light and glowing plankton, the dolphins swimming patterns look straight out of a fairytale. The visuals appear dream-like, as the bioluminescent plankton gently outline the dolphins in a sea of black, like soft fireworks or neon lights.
Want to see for yourself? Check out my video clips below for a quick glance but for the whole thig make sure to check out the whole documentary, Life that Glows, with David Attenborough which aired on BBC2 at 9pm on May 9th, 2016. As Sir David said for himself in an exclusive interview with BBC Wildlife, “It just seems to me like the most magical thing.” After watching it myself, I have to say I agree!