What's Translucent Blue with a White Body and Orange Frills? You'll Find It in the Tidepools

Contributor Hope Swank shares her passion for tide pooling and gives tips on how and when to look.

Spring break was supposed to involve an entire week of sleeping in and letting the sun wake me up instead of NPR.  But Tuesday morning, my alarm was set for 6:40 a.m. -- even earlier that I have to get up for work.  And rather than stumbling around in my usual stupor, I sprang up and out the door, barely stopping to fill my coffee mug.

Tuesday was one of the lowest tides of the year and I didn’t want to miss it.  Ever since I moved to the California coast I have been fascinated by the variety of life nestled down among the rocks. From brightly covered invertebrates to elusive eels and feisty crabs, there are surprises everywhere you look.

That morning, I met other tidepool enthusiasts at the rocks just north of Pigeon Point Lighthouse in Pescadero, my personal favorite spot.  We flipped over rocks and found porcelain crabs scurrying away.  We saw beautiful giant green anemones with striped, flowery tentacles.  We saw purple and orange Ochre Stars, and many colors of Bat Stars.  We also found a gumboot chiton, which is an ancient mollusc that resembles a deflated football.

My favorite finds were the three different types of nudibranchs, or sea slugs.  Their size makes them difficult to spot, even though they are usually brightly colored.  The first time I saw one was in the touch tank at San Mateo Outdoor Education, where I was an intern a few years ago.  I thought it looked like one of those toys you pay 25 cents for in a gumball machine.  But now they are my favorite thing to look for.

“Nudibranch” is Latin for “naked lung.” Found on the outside of their bodies, their lungs are extremely beautiful.  On Tuesday we also found two sea lemons, which look like the underwater cousins of banana slugs -- except for the flower-like gills open on their backs.  We also found a clown nudibranch, named for its white body and orange and red frills.  In addition there was the opalescent nudibranch, Hermessenda Crasicornis, which dazzles with a translucent blue, white body and orange frills.

Tide pooling has been a passion of mine ever since I moved to the coast.  Looking back, this is what I was always doing when my family vacationed at the beach.  It’s what most kids do. They can’t resist touching an anemone’s tentacles, or trying to get a hermit crab to walk across their palm.  Now, as a teacher, I cherish taking students to the tide pools because it’s a time where their curiosity can really take over.  But you don’t have to be a kid to enjoy a trip to the rocky coast.  Go on your own!  Here are some tips:

Tidepool Safety and Etiquette

  • Check the tides before going.  You can look online here or pick up a book from the marina.
  • The lower the numbers for the tides, the better.  Negative tides are the best.  Start when the tide is still going out, about half an hour before the lowest low.
  • It is illegal to collect animals, plants or shells unless you have a permit.
  • Wear shoes you don’t mind getting wet, and walk slowly.
  • Leave all animals where you find them.  Each tide pool is an entire world in itself.  Animals like their homes!
  • Don’t pick up animals attached to the sea floor or rocks.  That’s how they survive!
  • If you flip a rock over, make sure to gently put it back the way it was.
  • Don’t pick up an octopus.  Its bite is a lot worse than a bee sting.
  • Keep an eye on the ocean.  Watch out for waves!

You can tide pool at any of Half Moon Bay or the South Coast’s state beaches that have a rocky shore.   For a guided tour, check out the Fitzgerald Marine Reserve's website.

Jukebox Mom April 24, 2011 at 02:33 PM
Another great place to visit the critters of the tides is right in Moss Beach at the Fitzgerald Marine Reserve. www.fitzgeraldreserve.org/
Suzanne Black April 24, 2011 at 02:51 PM
The opalescent nudibranch looks like Hermissenda crassicornis, a real beauty!
Suzanne Black April 24, 2011 at 02:57 PM
I should have kept on looking through the wonderful photos! The aggregating anemones are likely to be Anthopleura elegantissima. Love the hermit crabs in snail shells and the beautiful violet spines on the sea urchins. Thanks for the treat; I didn't even have to get my feet wet.


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