Written By: Jenny Tindall
Three years ago, I went on a kayak camping trip near Strathcona Park and experienced something magical. During the day the water was a beautiful blue, clear and clean. Then at night, it sparkled. One night we took the kayaks out in the dark. Our paddles left behind trails of light in the ocean. We saw fish outlined by these brilliant blue lights. It is one of the best moments of my life, and I have bioluminescence to thank for it.
What is bioluminescence?
Bioluminescence is a chemical reaction that produces light within an organism’s body. To make this light the organism needs a molecule called luciferin. This molecule reacts with oxygen to produce light, and there are different types for different animals. Animals can control when they light up by regulating their chemical and brain processes.
Over 75% of deep-sea creatures can make this light. These include bacteria, algae, jellyfish, worms, crustaceans, sea stars, fish, sharks, and more. Some animals can take up bacteria that light up but most already have the chemicals to begin with.
Why does bioluminescence happen?
Bioluminescence is used for three main things: food, protection, and communication. Animals can use this to get their food. For example, anglerfish use lights on a rod in front of their face to lure prey into their mouths.
They can also use light to better see where food is which is very useful in the dark depths of the ocean. This light also serves as protection. Animals can save themselves by flashing brightly to scare off and startle other animals. Lighting up the surrounding area can also alert larger predators to the location of the animal producing the flashing, causing the bioluminescent animal to become prey itself. Its last main purpose is for communication. One case is the male Caribbean ostracod (a crustacean) which uses these signals on its upper lip to attract females.
The night I went kayaking I likely saw the Noctiluca Scintillans plankton. These organisms live at the surface of the ocean. They produce flashes of light in response to physical disturbances. When we paddled through the water we disturbed the plankton causing the ocean to light up and sparkle.
What can this be used for?
Learning more about bioluminescence is important and can lead to helpful resources in our lives. For example, there is ongoing research into the use of bioluminescence as a sustainable light source for cities. Additionally, other important discoveries and tools are being made in the medical field. For instance, bioluminescence can light up structures in the brain for diagnostics and tracking the progressions of cancers and other illnesses.