Not everything is visible in light! Of all the evolutionary miracles that can be seen on earth, perhaps the most remarkable is the ability of some land and sea organisms to produce light in total darkness. When one thinks of bioluminescence, typically the first thing that comes to mind is the firefly flashing green at night. The same mechanism for creating light is the same as commercially produced glow sticks that are used in some toys, for recreation, or for emergency situations. And what concert would be complete without holding up lighters, cellphones, and/or glow sticks!
What is bioluminescence?
Without getting into the actual technical details, it generally involves two chemicals reacting with each other to produce light. This chemical process is call chemiluminescence, such as the aforementioned glow sticks. When this process is produced by a living organism it is then referred to as bioluminescence.
For the science nerds, one might believe bioluminescence is archaic way for producing light. But in reality it is the most efficient way to produce light! A typical LED light bulb produces 35% light and 65% heat for a unit of electrical energy. Bioluminescent creatures convert nearly 100% of their energy to light with none wasted on heat generation.
What organisms create light?
A vast majority of the bioluminescent organisms live in the ocean. Current research indicates that approximately 1,500 known marine fish luminesce. Other organisms include bacteria, crustaceans, jellyfish, sea stars, squids, plankton, and even some sharks. On the terrestrial side, some insects, worms, and fungi are known to luminesce. Besides fireflies and lighting bugs, the glow worms inhabiting the caves in New Zealand are well known for their “show of glow.”
Obviously, organisms glow for a reason other than just being cool looking. Bioluminescence is primarily used to hunt prey, defend against predators, and attract mates. In the case of plankton, being able to emit short bursts of light, along with millions of your companions, would most definitely deter a predator long enough to be spared becoming dinner! Some animals, such as sperm whales, can actually benefit from the presence bioluminescent plankton. As mentioned, when predatory fish approach bioluminescent plankton, they glow for a distraction. This light attracts sperm whales which eat the fish. A very classic example of a great symbiotic relationship!
About the Photo
There are many aspects of the Washington coast I find quite appealing; towering sea stacks and rocky outcrops adorned with evergreen trees, rock arches, sandy beaches, primitive areas, and dark skies. Those dark skies were one of my primarily motives for traveling to the Olympic Peninsula late in August. I have had the fortunate over the years to spend many nights viewing the Milky Way and other celestial attractions in Colorado, South Dakota, and Utah. But since moving to Washington, I hadn’t yet photographed many nights skies. Of course in Washington, astrophotography is always at the mercy of the weather. But with some weather planning and a lot of luck, my visit to the Cape Flattery area proved more lucky than I first thought. As I have mentioned before, astrophotography involves using a long shutter speed to capture light our eyes cannot see. And as it turns out, utilizing the long shutter speeds increased my ability to capture bioluminescent organisms as well. From my research, it appears the bioluminescent creatures I photographed were small single-celled plankton. During certain times of the year and conditions, plankton blooms allow for these amazing light shows. Additionally, because I was shooting at the new moon to best capture the Milky Way, that is also the time the plankton are closer to the surface and more visible. And, yes, they were visible to the naked eye, but the longer camera exposure accentuated the vibrancy. It is one the most beautiful colors I’ve ever witnessed in nature. This color is so unique, I now refer to it as plankton blue. As you noticed, the vibrant color is isolated around rocks and the shoreline. I suspect millions if not billions of plankton were present everywhere in that ocean scene, but they will only emit light when disturbed or threatened. The crashing sea on the rocks provided the conditions for the disturbance and the millions of flickering lights in unison created the glow. I don’t know if I will ever be in a situation with all the right conditions to view this amazing phenomenon again, but for one magical evening I was able to experience “sea sparkles” for many hours.
(Glow worms in New Zealand cave - Photograph: Criskorah)