Jun 25 2005

San Diego Red Tide

Published by at 12:25 pm under San Diego

If you’ve never seen a red tide at night and you are in the San Diego area, I urge you to go take a look after dark.

I grabbed this from Flickr. I wonder how sudsyfist set the camera up.

It looks like the tops of the waves are alive with blue, electric flame. The effect is subtle until your eyes get used to the dark, then it can be quite dramatic.

For more about the red tide, I’ll paste something sent to the Scripps Institute of Oceanography (part of UCSD) here:

The red tide has finally arrived. Innumerable tiny single-celled organisms called “dinoflagellates” (Greek for “whirling whips”) have been growing slowly over the past few months, and have finally reached such high concentrations that they color the water.

The dominant species this year is Lingulodinium polyedrum. These cells are golden-brown, covered in a prehistoric-looking set of cellulose plates. Two flagella allow it to swim, moving upward toward the sun during the day to photosynthesize. This is why the brown color of the water is most intense around noon: the organisms aggregate at the surface if the wind is weak enough.

This dinoflagellate is not toxic – if you drank the water you’d die of salt-water overload before you would die from anything related to the red tide. On the other hand, it will give us one of nature’s most beautiful displays: the dinoflagellates are bioluminescent. Each cell can create its own eerie blue light. It does this in a sudden flash, presumably to either warn away predators, or to attract visual predators to eat the organisms that are eating the dinoflagellates.

The cells will also flash when they are disturbed by mixing. So the breaking waves, swimming fish, surfers, swimmers, and kayakers will all be lit up with a blue glow at night. Go down to the beach after sunset, to a place where there are not too many lights, and you will be in for a visual treat. Even your footsteps will sparkle in the sand! Swimming in the red tide is amazing. Your hands will glow in front of you, and you’ll be covered in tiny glowing stars when you come out of the water.

One of my favorite things to do is to get a jar full of water, and take it home. I put mine in the bathroom, where it is cool and has no windows. After the sun sets, my daughter and I go in, shut the door, wait for our eyes to acclimate to the dark, and then play with the “glow-in-the-dark” water. Last night we used an electric toothbrush to get a glowing blue blob. The grand finale is when we add vinegar: the acid causes all the cells it touches to give off a burst of light. The show will be over (the cells cannot bioluminesce again for another day – assuming they survive the acid), but it will be spectacular! And it’s all free!

These red tides are unpredictable. I’ve worked on them for years, and I still could not tell you whether we’re going to have one in a given year, when it will occur, or even what species it will be (we have two main species that cause local red tides). They tend to occur in the summer and early fall, though I’ve seen them in winter and spring. They are moved around by the water currents. This one may be the same one that was in Redondo Beach two weeks ago. I think that this bloom has been trying to get going for many months – the cells have been in the water since about February, but the conditions have not been right for it to really get dense. The bloom probably started about 30 feet below the surface, and has been growing down there for some time. Divers might have noticed a band of bioluminescence near that depth at night. Now that it has warmed up a bit, and the sun is actually shining, the cells have moved upward, forming a dense layer near the surface.

I’m guessing that this red tide will last at least two weeks, and maybe a lot longer. It depends a lot on the weather: if it is too windy, the turbulence will kill the cells, and the bloom will rapidly disappear. The ocean currents can also sweep it away. But we might have a great oceanic light show for July 4th!

Peter Franks

10 responses so far

10 Responses to “San Diego Red Tide”

  1. SudsyFiston 27 Jun 2005 at 10:45 am

    > I wonder how sudsyfist set the camera up.

    I leave the EXIF data public on my photos; just click the More properties link under the Additional Information on the right side of each photo’s page.

    It was a really challenging shoot, given the almost unpredictable, short-lived, moving subject in the dark: lots of playing with exposure and ISO, while also hoping to click the shutter at precisely the right time. ‘Twas fun, though — it was just amazing to be there.

  2. Christineon 29 Jun 2005 at 8:59 pm

    > I wonder how sudsyfist set the camera up.

    I wonder how they came up with their handle :O. Communist dishwasher?

  3. […] ing the blue glow, in addition to further explanations. Update 7/1/2005: Declan points to a post of his about the phenomenon in the comments here. This entry was posted […]

  4. aimeeon 05 Jul 2005 at 9:01 pm

    Scripps Instutie of Oceanography states that vibrio cholerae is present in San Diego red tide. Therefore, the tide is dangerous to human beings. Please be cautious

    I asked for a link on this:

    sure. here it is. thanks for asking. AEM stands for Applied and
    Environmental Microbiology. Here is the quote that worries me.

    “Under the conditions tested, free-living V. cholerae was able to reach
    concentrations per milliliter that were up to 3 orders of magnitude higher
    than the known minimum infectious dose (104 cell ml-1) and remained viable
    under many conditions. If applicable to the complex conditions in marine
    ecosystems, our results suggest an important role of the growth of
    free-living V. cholerae in disease propagation and prevention during
    phytoplankton blooms.”


  5. Caryon 10 Jul 2005 at 11:42 pm

    The red tide phenomenom is perplexing to those of us who are not marine biologists. I was always told they are not dangerous; and now v. cholerae is a possibility. Tthat sounds ominous; especially because my 12 year-old was boogie-boarding in a serious red tide today in Northern Baja(K 22). It is a beautiful site to behold at night. I just worry about keeping my kids out of the water while on vacation in Baja next week. Thanks for the great pictures. C

  6. Angelaon 16 Jul 2005 at 2:14 pm

    I saw the red tide glow last night at Corona Del Mar in Orange County. It
    was so amazing. It was very romantic alone with my husband. Very

  7. Colynnon 12 Aug 2005 at 10:24 am

    I was in Oceanside this past week, and it was the most amazing thing I have ever
    seen! I was captivated for hours at a time at night, I just could seen to tear my eyes away from the beautiful display!

  8. Ckeithon 15 Aug 2005 at 2:21 pm

    I’ve seen this effect for years, but went out in the surf on my board for the 1st time last weekend. The effect 100 yards offshore is 10X more spectacular! My arms paddling was an incredible light show!

  9. Judyon 16 Aug 2005 at 7:30 pm

    Coronado Dog Beach did not have red tide Aug. 11, 2005, but yesterday the 15th was very thick. Seems it was in Encinitas last week and it is moving south. There is no odor, but really gross looking in day, lovely at night. I am concerned about the v. cholorae. My sons have continued to surf and my dogs have been under the waves extensively. I have always heard that the red tide is not harmful, but now it seems that has changed. I would like a clear answer if possible. It is awesome at night and great fun to swim in – with grunion running next week it should be wonderfully interesting. Thanks! Also I always learned that green water was high in phytoplankton and brown or red for zooplankton. Am a wrong on that too????

  10. Hannah Martinezon 15 Aug 2008 at 11:03 am

    Swimming in the red tide at night was on of the most amazing experiences i will ever have. To see a phenomenon is on thing. . . To be in one (fully) is like a dream come true.

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