Along the coast of Southern California, a species of algae called dinoflagellates have been blooming since March. By day, congregations of the dinoflagellates flock to the ocean surface to capture the sunlight, with as many as 20 million cells per liter. The “sunscreened” cells give off a reddish-brown color, known as a “red tide.” But as darkness falls, the agitated algae glow neon blue in a stunning display.
These unpredictable algal blooms have been observed all over the world, from tropical regions to Alaska, lasting anywhere from one week to a month or more. Although not all red tides produce bioluminescence, the recent event in California has been one of the largest to happen in the area in about a decade. Despite the state’s lockdown measures, many residents managed to observe this spectacle whilst being warned to adhere to physical distancing guidelines.
With reports that this tide has started to degrade, we take a look back at some of the highlights from this season’s bioluminescent phenomenon.
Dolphins In Bioluminescence
Californian photographer Patrick Coyne managed to capture these dolphins taking a night-time swim, lighting up the ocean as they went. When the cascades of dinoflagellates are disturbed by waves or other movements in the water, such as from dolphins, two chemicals produced by the algae (the enzyme luciferase and the compound luciferin) react in a flash of electric blue. In an Instagram post, Coyne described his experience as “one of the most magical nights of his life.”
Boat Wake Trail
The Los Angeles County Sheriff’s Department took to Facebook to share their illuminating boat patrol. Streams of the bioluminescent algae left a trail in the boat’s wake as it cruised down to the shore.
Surfing In The Glowing Waves
Surfer Blair Conklin skimmed the ocean’s surface at night, with the algae acting as a torch. There is not really any way to predict how long this phenomenon will last or when they will occur. According to bioluminescence expert Michael Latz of the Scripps Institute of Oceanography, UC San Diego, “while some phytoplankton blooms are stimulated by nutrient runoff, those of Lingulodinium polyedra (dinoflagellate) are associated with relaxed upwelling and stratified water column conditions.”
Footsteps In The Algae
Even in the sand, washed up algae lit up revelers' paths. Some red tides, especially in the Mediterranean, spell bad news for marine life as they are caused by species that produce deadly or harmful toxins. In California, the majority of algal blooms are actually harmless and even beneficial as they provide food for sea creatures.
As the current red tide fades away, the decaying algae leave behind a strong odor as the process depletes oxygen in the water, which could cause some fish to die. However, in a time of darkness, the season’s bioluminescent performance has brought some much-needed light into a lot of people’s lives.