Why do California waters light up blue? | ET REALITY


California seems to have had a brilliant start to the year, and we’re not just talking about the Hollywood stars gathering for awards season. We are talking about bioluminescent algae.


Bioluminescent algae. It’s not new, but this latest algae bloom in parts of Southern and Northern California is causing waves and areas of water in the Pacific Ocean to glow fluorescent blues, attracting surfers and other enthusiasts to watch and share photos of an ocean bright blue. . The water is so luminescent when shaken at night that it looks like surfers are riding waves in “Avatar: The Way of Water.”

Bioluminescence is the emission of light by living organisms. It can be used “to warn or evade predators, attract or detect prey, and for communication between members of the same species,” according to the National Ocean Service, an office within the National Oceanic and Atmospheric Administration. In the ocean, the phenomenon is not uncommon: bacteria, fish, jellyfish, sharks and other animals and organisms can be bioluminescent.

The light emitted by a bioluminescent organism is produced by energy released by chemical reactions that occur within the organism. (A firefly, for example, is a bioluminescent being).

The algae blooming in California right now are a type of marine phytoplankton called dinoflagellates, primarily one particular species that is a very vibrant bioluminescence producer, called Lingulodinium polyedra, said Dr. Clarissa Anderson, director of the Ocean Observation System. Southern California Coastal Oceans. Dr. Anderson added that these algae were not related to the more harmful blue-green algae, or cyanobacteria, which can make animals sick, suffocate ecosystems and seem much less magical.

The algae in California right now is linked to the dinoflagellate that causes “red tides,” Dr. Anderson said, causing the water to take on a rusty red tint during the day. These red tides can be harmful: one killed a large number of fish in the San Francisco Bay area in 2022 (the organism that causes red tides produces a toxin that can make animals and humans sick, including respiratory symptoms).

And while California glow algae can produce a toxin, “it is not particularly potent or harmful to wildlife or humans,” Dr. Anderson said in an email.

The seaweed has been seen vibrant where the waves break. The best option to find them is to search in warmer weather and when the water is calm.

Interest in night tours to see the phenomenon has increased. Some whale watching tour operators offer bioluminescent tours and lately people have been posting luminescent photos on social media.

Bioluminescent algae are generally most easily detected between June and October. But increasingly, it’s becoming a year-round thing, said Dallas Smith, operations manager for Blue Waters Kayaking in Northern California. “It’s one of those questions,” he said: “Are we going to go out and look for it more, or was it always there and getting stronger?”

Tours to view bioluminescence in water have become increasingly popular, especially in the last decade or so, Smith said.

Tours last about three hours, as guides lead kayakers to paddle about a mile on the water on calm nights with little moonlight.

Mr. Smith and his colleagues take people out into the bay in kayaks to see the bioluminescence. It’s never a guarantee that glowing fish or algae will grace the horizon, but if it’s a bad night for bioluminescence, people can always look up instead of down to capture a magnificent sky full of stars, he said.

Smith has toured bioluminescence in the Bay Area for more than two decades, he said, but the thing never gets old. “Every time you see one of them beneath you in brilliant bioluminescence,” she said of the underwater creatures, “its body illuminates a glowing outline of its appearance, which always stays with you.”

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