In recent days, Southern California’s coastal waters have been adorned with a captivating and rare sight – a nightly “beautiful blue glow” that has left residents and observers in awe. Videos shared from the region showcase dolphins gracefully leaping through the sparkling waves, boats seemingly trailing luminous trails as they navigate the waters, and beachgoers leaving neon blue sparks with each step in the sand.
Described as “magical” by Jessica Roame, a whale watching educator at Davey’s Locker, a local tour agency, the phenomenon has left many wondering about its origins. According to Roame, the mesmerizing spectacle can be attributed to a significant proliferation of photosynthetic plankton along the Southern California coastline.
The Scripps Institution of Oceanography has shed light on this natural wonder, linking it to a resurgence of the red tide phenomenon, which the region experienced notably in 2020. Red tide refers to a harmful bloom of algae that is laden with toxins capable of causing fish die-offs and depleting oxygen levels in the water. Furthermore, red tide can have adverse effects on human health, irritating respiratory systems, eyes, and nasal passages.
In this particular instance, the plankton responsible for the bioluminescence are dinoflagellates. Scripps explains that these dinoflagellates migrate towards the ocean’s surface during daylight hours to facilitate photosynthesis. However, as night descends, some dinoflagellates remain near the surface, leading to the mesmerizing bioluminescent display.
Scripps’ statement from the 2020 event clarifies, “Dinoflagellates use bioluminescence as a predator avoidance behavior. When the phytoplankton are agitated by waves or other movement in the water, they emit a dazzling neon blue glow at night.”
Roame elaborates, “When the waves crash or boats and marine life traverse through the water, it agitates the plankton, creating the beautiful blue glow.”
This striking phenomenon was previously considered a rare occurrence, happening only once every five to ten years. However, it has become more frequent, occurring a few times a year, prompting speculation about its connection to climate change.
Roame suggests that the increasing frequency may be tied to climate change. Rising global air temperatures elevate ocean temperatures, intensify storms, and increase runoff into waterways. These factors create favorable conditions for algal blooms, including harmful ones.
The Environmental Protection Agency underscores this link, stating, “With a changing climate, harmful algal blooms can occur more often, in more fresh or marine waterbodies, and can be more intense.” Even non-toxic algal blooms can negatively impact aquatic life by obstructing sunlight and obstructing fish gills. Additionally, they can give rise to “dead zones,” areas in water with diminished oxygen levels where aquatic life cannot survive.
As Southern California’s coastline continues to sparkle with this breathtaking natural display, it serves as a reminder of the intricate relationship between our environment and the changing climate.