The Hypnosis of Bioluminescence

Originally published by Adventure Collection

Their traps were set: Along a dark, dripping wall of stone, silk strands dangled in waiting. The victims, attracted to an irresistible glow, would be caught in the pearls of glue that shone like drops of dew in my flashlight beams.

I stood before the wall of silk as the last of my classmates picked their way in single file down the forest trail above. We pooled together at a lookout in this gully of Lamington National Park in Queensland, Australia, and then shut off our flashlights.

Pinpricks of whitish blue decorated the wall like a web of holiday lights and pulsed like an electric neural network. The scene was beautiful: an intentional hypnosis.

The phenomenon we witnessed that night is called bioluminescence, the production of light by living organisms. The pinpricks of blue were the taillights of glowworms, a type of larvae found not only in Australia, but also in New Zealand. It’s the same chemistry that fireflies use to light their tails as well.

But bioluminescence is not unique to insects like glowworms and fireflies. As biologist and deep-sea explorer Dr. Edith Widder described in her TEDTalk aboard the National Geographic Endeavour in 2010, bioluminescence can be seen in its most abundant and spectacular form in the sea.

“In general, on land, it’s really rare,” she said. “In the ocean, it’s the rule, rather than the exception.”

In some areas, up to 90 percent of marine life—including fish, crustaceans, corals, jellyfish, and krill—is bioluminescent. This creates some truly spectacular scenes, which Widder has witnessed by diving to depths of more than 800 feet and turning off the lights of her submersibles.

“I was totally unprepared for how much [bioluminescence] there was, and how spectacular it was,” Widder said in her talk. “[There were] puffs and billows of what looked like luminous blue smoke, and explosions of sparks that would swirl up,” she said, “like icy blue embers.”

The science of bioluminescence, Widder said, has become an addiction of hers. And she isn’t the only one enticed by it: Her talk has been viewed more than 560,000 times to date.

What causes this magic, and where—beyond Australia’s rainforest and 880 feet below the surface of the ocean—can we find it?

THE LIGHT BEARERS: THE HOW AND WHY OF BIOLUMINESCENCE

Generally, only two ingredients are needed to produce bioluminescence, each named after Lucifer the light-bearer: a luciferase enzyme that drives the reaction, and a luciferin chemical that produces the light. (UC Santa Barbara has a simple online animation that illustrates the phenomenon.)

The reaction of these chemicals explains the how behind bioluminescence, but not the why. Producing your own light is a biologically costly process, but there are several ways in which it can pay off.

One of these benefits is in hunting prey. In the depths of the ocean, light in the red spectrum cannot penetrate. (Blue light travels the farthest, which is why the majority of bioluminescence is blue, and why the majority of life in the deep ocean can see only blue.) Animals that can both produce and see red light have the opportunity to use their bioluminescence to sneak up on unsuspecting organisms. In other instances, predators use their bioluminescence as a glittering lure for their prey, in much the same way that the glowworms do in Australia.

The prey, on the other hand, use their bioluminescence for defense. Some shoot streams of light to blind their attackers; others flicker in gorgeous displays meant to attract the predators of their predators. In shallow waters, the most common type of bioluminescence comes from phytoplankton as they are disturbed.

BEYOND THE DEEP: DANCING WITH THE BIOLUMINESCENCE

Often, it is the bioluminescent phytoplankton that leave the greatest impression on travelers. Lynn Petzold has seen her fair share of bioluminescence during her twenty-three years as a faculty instructor for NOLS, but her most remarkable experience came recently, while leading a two-week kayaking course in the Sea of Cortez in February of 2014.

It was a cool, unusually calm morning toward the end of the trip, at a campsite just north of the fishing town of San Nicolas. Petzold had gotten a preview of the coming light show the night before, as bioluminescent sparks lit up her footsteps in the sand like diamonds. But the full spectacle would come just before dawn.

About half an hour before sunrise, with the mountains of Baja silhouetted against the skyline, the only lights on the sea came from the headlamps of the kayakers—and the water beneath them.

“It was like somebody had poured paint into the water,” Petzold says. She compares the swirls of turquoise-blue light to the curves of a long, billowing skirt: “It moves in a very fluid, beautiful way. It felt like our kayaks and paddles were dancing on the water with the bioluminescence.”

When the kayakers agitated the water, the light really came alive. They began to knock their paddles into the sea, creating thick splashes of color. Dipping their hands under the surface, they played giddily with the liquid light.

Soon, a thick curve of sun began to appear on the water’s horizon. The brilliant blue of bioluminescence began to fade, replaced by oranges and pinks reflecting on the coastline and the cliffs. Petzold says that in the golden light of the sunrise, the mountains of Baja began to shine with an irresistible glow.