Bioluminescence is a strange and beautiful phenomenon that provides us with some of the most ethereal, natural sights. In recent days, news channels have been abuzz with reports of the scintillating vision of colorful and glowing waves crashing on the shores of southern California.
The images are stunning and have enthralled beach-goers and the online world alike. It is another one of mother nature’s treats, which is magical and yet strongly rooted in science. But what causes this spectral occurrence?
How does bioluminescence occur?
In the purest sense, bioluminescence is light emitted by a living organism.
- When a chemical reaction occurs in the organism, light is emitted from it.
- An enzyme called luciferase is secreted by the bioluminescent organism and is primarily responsible for this phenomenon.
- Luciferase catalyzes the oxidation of luciferin, which is the molecule that emits the light as it oxidizes and decays.
- The nature of the chemical process is not exactly identical among all bioluminescent organisms. Other elements may be required.
- Depending on the organism, calcium, magnesium, or a different class of enzymes called photoproteins take part in the reaction.
- The only common factor, however, is that oxygen is ubiquitous in all bioluminescent reactions.
What causes bioluminescent waves in the ocean?
The stunning neon phosphorescence, which we witness as a largely marine phenomenon, is caused by algae.
- Marine bioluminescence is caused by dinoflagellates. They are unicellular organisms and are mostly plankton.
- Many dinoflagellates are photosynthetic. They use sunlight to manufacture their own food. Some feed on fish eggs or other organisms.
- Some are parasitic and live on fish and algae. While some other types are symbiotic and live on jellyfish and coral, sharing their photosynthesized energy with them.
- When a large concentration of these algae is brought to the surface of the ocean, it causes a “bloom” or a “red tide.”
- The exact ecological or meteorological factors that cause a red tide are subjects of ongoing research.
- The popular theory is that when sunshine warms the water surface, it invites the algae to the surface. They rapidly reproduce and multiply, causing the bloom.
- They sometimes turn bioluminescent to ward off predators. When this is witnessed after dark, it is a spectacular sight.
- Bioluminescence is a chemical reaction that occurs when there is a mechanical stimulus. When the algae are disturbed by a passing boat or the stirring of the water by the swell of a wave, they emit a brief bluish flash which lasts less than a second.
- This is why we see bioluminescence in moving water. Examples of this are the crest of a wave, the wake of a boat, oar, or surfboard.
Is it harmful?
Red tides can cause harmful health effects.
- Lingulodinium polyhedra is the species of dinoflagellate. It causes the red tide on the coast of southern California. While they are not toxic in those Pacific waters, the same species inhabiting the Mediterranean Sea secrete yessotoxin, causing nerve damage like temporary paralysis.
- A red tide does contain other microbes, even if it is not toxic by itself. Swimming in water that is infested with this algal bloom could have adverse health effects.
- Secondary poisoning is possible from red tides. Saxitoxin, for example, infests and accumulates in shellfish. It can cause paralytic shellfish poisoning when the contaminated shellfish are eaten.
- Some other types of shellfish poisoning caused by red tides are respiratory failure, muscular problems, and digestive problems.
- Other types of toxins are released into the air and can cause respiratory difficulties on the coast.
Are marine bioluminescent occurrences being monitored and tracked?
Government and academic departments are involved in tracking red tides in the US.
- The US National Oceanic and Atmospheric Administration monitors red tides for toxicity, in conjunction with local partners like university research centers on the west, east and gulf coasts of the US.
- The Scripps Oceanography department at the University of California San Diego has more than one system that collects and analyzes water samples from the ocean to monitor it for harmful algal presence.
- Scripps has been performing extensive research in this field to determine the behavior and causes of red tides since the early twentieth century.
- Florida Fish and Wildlife, the University of Southern Florida and various government and academic partners are involved in the collaboration to track and monitor the algal blooms.
Where can we see bioluminescent tides around the world?
Red tides and bioluminescent waves are not restricted to any particular geographic region. They can occur in any marine environment around the world.
- Red tides have been witnessed in tropical beaches as well as frigid marine waters.
- Bioluminescent tides are found in saltwater but not in fresh water.
- In the US, they occur most often on the southern California coast and the gulf coast of Florida. They are also witnessed in Washington, Kentucky, New Jersey and Alaska.
- In tropical areas, popular marine hot spots in Vietnam, Thailand and Maldives enjoy frequent displays of bioluminescent tides.
- The coastal waters of Australia, New Zealand and Japan are also habitats for algal blooms.
Bioluminescence is undoubtedly one of nature’s most dazzling displays. By exercising caution and good judgment, we can safely enjoy this magical sight in all its mesmerizing glory.