Red Tide Arrives In So Cal: What? Where? How Bad?

red tide glowing waves
Red Tide Causes Glowing Waves

Most Recent Red Tide In San Diego

The most recent red tide in Southern California was reported offshore back in early April of 2022 and it seems to have settled onto the shoreline of many San Diego and Southern California beaches over the past week. Reports of the red tide have been made as far south as Baja California and as far north as Santa Barbara County.

How Long Will It Last?

There’s no way of knowing how long the red tide will last, but a typical red tide for Southern California lasts between 1 and 2 weeks. As of now, it falls short of the one we experienced back in 2020. The red tide in 2020 lasted some 7 weeks and was extremely dense.

Look for sea foam to develop along the shoreline as a sign that the algae/phytoplankton are dying off and that the red tide is coming to an end.

Which Beaches Are Affected?

The best place to see the glowing waves at the moment will be between La Jolla and Carlsbad in San Diego County.

San Diego County Red Tide

The most southern beaches from Imperial Beach through Point Loma have remained clean so far. As you head north from Sunset Cliffs though Carlsbad, most beaches are affected but it’s certainly not as thick as it was back in 2020.

Oceanside was reported to have been clean by a few sources but other reports have come in saying red tide is present. It’s likely that it’s been back and forth and has yet to settle in.

The Southern California Coastal Ocean Observing System released this statement on April 27th, 2022:

A very visible red tide moved onshore and spread throughout La Jolla. The species responsible for the dark red water is Lingulodinium polyedra (L. poly). This is the species known to bloom frequently here and produces bioluminescence at night. This bloom has been waxing and waning over the last few weeks and appears to have finally set in.”

Orange County Red Tide

Red tide has been reported at San Clemente, Dana Point, Laguna Beach, Bolsa Chica, and Huntington Beach. Although I have yet to receive any intel on Seal Beach, I’d bet it’s present.

On April 25th, 2022, the Southern California Coastal Ocean Observing System released this statement:

“Monday the water was bright orange-red and the dominant plankton was Akashiwo sanguinea. This species of plankton produces a slimy surfactant that may cause harm to birds, fish, or bivalves if the bloom is dense enough. As of Wednesday, the bloom is showing signs of decreasing at this station.”

LA County Red Tide

While red tide has been reported into LA County and as far north as Santa Barbara, these waters don’t seem to be affected much. Most typical beach goers and anglers wouldn’t know it was there if they hadn’t heard of it via a news source as LA and Santa Barbara are experiencing “healthy amounts” of algae bloom.

Red Tide in Southern California

On average, a typical red tide in Southern California lasts only 1-2 weeks and the concentration is usually minimal. Sometimes, it remains offshore and dies off before it can even reach the crashing waves in high density. The red tide that took place in 2020 was one of the longest-lasting and densest red tides San Diego has ever experienced.

While much of the general population is attracted to this phenomenon, the red tides like the one we experienced in 2020 can be harmful to both sea animals as well as humans.

What Is A Red Tide?

You’ve likely heard about or seen some of the spectacular events like glowing waves and even glowing dolphins! It really is a spectacular sight to see, but what is a red tide?

A red tide is caused by an excessive amount of phytoplankton in high concentrations within the ocean waters (1). Commonly referred to as a “bloom”, this phenomenon takes place all around the world with California just being one of many places. Phytoplankton (single-celled) are technically classified as a type of algae. So when you hear the term “algae bloom”, this is why (2).

The red tides that Southern California typically experiencines are caused by a specific type of phytoplankton called Lingulodinium polyedra also referred to as L. Poly. L. Poly is the usual offender when it comes to determining the root of an algae bloom on the west coast.

Are Red Tides Bad For You?

Before you get too freaked out, it’s worth mentioning that the red tides that occur in Southern California usually don’t pose a significant direct threat to the marine ecosystem and pose minimal threat to human health in the event of consumption. But, it certainly can. In places like Florida, red tides have the potential to wipe out thousands and thousands of marine animals. Luckily, Southern California usually isn’t at any such risk.

It’s important to note that L. Poly can produce yessotoxin which can build up in crustaceans causing health risks all around (3). A basic understanding of the danger is the concept of sand crabs as a food source for common surf species. Phytoplakton are the basic food source for the animals of the sea. As we move up the food chain from plankton, to sand crabs, fish, and eventually to birds of prey and even humans.

Are Red Tides Bad For Fishing?

Since red tides can be toxic, they’re generally not “good” for fishing. Although, in low density and short durations, red tides can signal warming waters in the spring time which is good for the summertime season. Prolonged and dense red tides can push fish out of areas and even kill them.

Should You Eat Fish During a Red Tide?

Technically, the red tied affects only the internal organs and blood contents so if you gut a fish properly, your fish should be safe to consume. But, if you accidentally cut into an organ or you get blood or other fish guts/fluid in your meat, it may not be safe to consume. As a rule of thumb, I generally don’t keep any fish during red tides and after heavy rains (due to sewer run-off).

Why Do The Waves Glow?

Perhaps the most mysterious aspect of the red tide, “why do the waves glow?” can be answered in very simple terms. The answer is bioluminescence. More specifically, bioluminescence upon agitation. These specific phytoplankton produce bioluminescent light when they are so called “agitated”. Meaning that when a wave crashes, or a fish or dolphin breaks the surface of the water, the phytoplankton are thrown about and will produce their “glow” causing the waves to appear as so.

Depending at which beach or bay you find yourself, you may even be able to see your footprints begin to glow. This will be determined by how close the phytoplankton have come to shore.

When Do Red Tides Occur?

The “when” and the “why” are closely related (at least for the reason it occurs on the West Coast). The phytoplankton, L. Poly thrives upon the transition to warmer waters, as is the case with many different types of algae. The 2020 red tide occurred just after our water temps rose by 2-3 degrees in a very short period of time.

Given this information, brief red tides in So Cal can be seen as a good sign for surf anglers. It shows that the waters are warming and that peak season surf fishing is just around the corner. Usually, as the waters warm, species like the California corbina, spotfin croaker, leopard shark, and other common species begin to repopulate the shallows along Southern California’s beaches.


(1) Langlois, G. (n.d.). Red Tides in California. Retrieved from

(2) Fondriest Environmental, Inc. “Algae, Phytoplankton and Chlorophyll.” Fundamentals of Environmental Measurements. 22 Oct. 2014. Web. <>.

(3) Paz, B., Daranas, A. H., Norte, M., Riobó, P., Franco, J. M., & Fernández, J. J. (2008, May 7). Yessotoxins, a group of marine polyether toxins: an overview. Retrieved from


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