There are a lot of really cool things to see and do in San Diego, but sometimes there are extra special things that happen here that are brilliant to see. One of those things is the bioluminescence in San Diego, where the sea glows neon blue in the dark. It’s a sight you will never forget!
But what is bioluminescence and how does it happen? And where and when can you see it? Read on to have all your questions about this phenomenon answered!
What is Bioluminescence?
Bioluminescence is light produced by living organisms, and in the case of bioluminescence in San Diego it is produced by algae called dinoflagellates. These dinoflagellates produce bioluminescence during red tides (algal blooms).
During the daytime, you’ll observe that the water looks a little murky and reddish…which is caused by the red tide. But at night, when these dinoflagellates get agitated by movement (the crashing of a wave, jostling into a rock, etc.), they emit a neon glow that lights the water bright blue. It’s a stunning sight to see!
When Can You See Bioluminescence in San Diego
So when can you see a bioluminescent beach in San Diego? Unfortunately, the red tide in San Diego is not predictable enough to say when you will be able to see bioluminescence. These blooms can happen throughout the year, although from what I’ve seen in recent years they seem to happen in the warmer months (March-October).
When a red tide occurs, the bioluminescence can last for a few days…a few weeks…or even a month or longer! Scientists really have no way to predict when a red tide will occur or how long it will last. It just depends on a lot of different factors, so if you hear of someone spotting bioluminescence then you should head out to the beach as soon as possible to have the best chance of seeing this cool event in person.
But currently (May 2020), we do have a red tide along the coast of San Diego! It’s been one of the most impressive displays in recent memory, so if you are interested in seeing a glow-in-the-dark beach then now is the time to go!
But what time should you go to see a bioluminescent display? This phenomenon starts up right after the sun sets, although the darker it is the easier it is to see the flashes of blue light. Many people recommend seeing it around two hours after sunset, although good displays also start as soon as around 30 minutes to an hour after the sun goes down.
Where to See Bioluminescence in San Diego
Depending on the algal bloom, red tides can be quite localized or can be widespread. Each bloom will have its own characteristics, which means you should pay attention to the buzz around you to hear where people are currently spotting bioluminescence.
With our most recent bioluminescence phenomenon (April/May 2020), the event is widespread so you can visit pretty much any beach in San Diego and San Diego County to experience this for yourself. If you’re looking for specifics, however, I’ve had good luck with La Jolla Shores and Moonlight Beach…as well as some luck spotting bioluminescence at Sunset Cliffs too.
Other Information You Should Know
If you want to see a glowing beach in San Diego, there are a few other things you should know:
While red tides can sometimes produce yessotoxin, local San Diego red tides of Lingulodinium polyedra (the dinoflagellates) do not usually produce this compound. That means it is usually safe to swim, surf, etc. even during a red tide here in San Diego. Can you imagine swimming in glowing neon blue water?
HOWEVER, you should always check current advisories before you decide to go out in the water during a red tide to make sure it is safe. Some people are also more sensitive to the red tide than others, so keep this in mind as well. While there is no public health warning for the current red tide (May 2020), it is still ultimately your choice on whether you go into the water or not.
If you decide to visit a bioluminescent beach in San Diego during the Spring 2020 bioluminescence, you should also be sure to follow current health orders including wearing a mask and staying 6 feet away from people not of your household. There are, understandably, a lot of people out looking at the display and you will want to be careful!
So go ahead and get out and enjoy the bioluminescence San Diego has to offer. It is an unforgettable sight that you will be sure to remember for years to come!
