Low Tide Redux

After our visit to the Oregon tide pools during the lowest tide, I’ve meant to get down to the beach in Olympia during low tide. Thankfully, the South Sound Estuary Association did a Beach Naturalist pilot program in August. They sent trained volunteer naturalists down to the beach to help us identify and appreciate the low tide creatures. My friends, Jen & Paul, accompanied Levi & I to a low tide event with the naturalists. We had a most excellent time.

Olympia’s beaches are totally different from the wild Pacific coast. We’re right at the end of Puget Ocean Sound, where it trickles into bays and harbors and estuaries. Things move more slowly here, like everything else in Olympia. There are huge beds of living sand dollars and lots of clams that squirt your ankles. The seaweed species are different. The waves are not as punishing.

We visited during a red tide. Red tide is a harmful algal bloom where the algae are releasing toxins into the water. Like, more toxins than normal. Eating things from the beach = off-limits. And you have to be sure to wash any skin that touches the water, or you can get an itchy, red, burning rash. But enough about itchy burning rashes, let’s talk about critters! Look at our naturalist friend. Isn’t she so nice and patient to answer all of our questions?

This was one of the first things that our naturalist friend pointed out to us. Have you seen something like this before? I have seen this a lot. I always thought that it was a broken, decomposing piece of seaweed. Literally, I have seen this hundreds of times and every single time I thought, “Oh look, a dead piece of seaweed.” Do you know what this is? It’s a tube worm (polychaete)!! My mind was blown. They live inside this tube, in the sand. When the tide comes in, their tentacles come out, looking for food. They wave their arms around like they just don’t care. The tide goes out, the worm cuddles up in the tube to avoid predators, disturbances, & us.

Then, we met this guy. It’s a spiny pink sea star (Pisaster brevispinus). These are more common in bays than the open coast. They love to eat clams, snails, cockles, geoducks, sand dollars and polychaetes. We saw lots of things that this guy loves during our time on the beach. It was like a Pisaster brevispinus all-you-can-eat buffet. No wonder it looks so happy…

^^ Smiling starfish

Next up: Sand Dollars! You have seen sand dollars before, right?

photo by my friend, Jen

They look different when they are alive.

photo by my friend, Jen

This is a bed of living sand dollars.

Levi was really good at spotting a bed of buried sand dollars. This kid has been to this beach innumerable times, but he still learned a lot with the naturalist. We had never noticed buried sand dollars before. It was cool to see him absorbing it all. He’s getting so old and smart, it seems like little things like tube worms and sand dollars are not going to interest him. Then, bang, he surprises me by being an expert sand dollar hunter while tip-toeing gently as to not crush any small things. “It’s totally different to walk on the beach when you know the kind of stuff that’s living under the sand,” he told me.

photo by my friend, Jen

But enough about teenagers. Back to sand dollars — Their underside looks furry!! It’s covered with cilia, which the sand dollars use for sensory input and finding food. They are not great hunters, and they don’t have a lot of locomotion, but if you lay the sand dollar cilia down on your palm, it will tickle your hand.

Paul turned over a giant rock and found a little green shore crab. This crab was so angry and defensive about the disruption. He was, as the naturalist explained, “locked and loaded.” Unfortunately (for him), he couldn’t figure out where the threat was coming from, so he was unable to attack us. All human fingers escaped unpinched and the crab was returned safely to his rocky hideout.

You know I’m a big plant nerd, and that fascination extends to the flora of the sea.

Sea lettuce (Ulva lactuca) is edible — unless there’s a red tide. This sea weed is only 2 cells thick. It’s amazing to me that a living thing can survive if it’s only 2 cells thick.

Red seaweed — I think this is in the Genus Gracilariopsis but my hands were too wet and sandy to write it down. It looks like spaghetti. If memory serves, it’s edible and can be used to make agar. You’re familiar with agar if you’ve ever cultured cells or used a vegetarian gelatin substitute, right? Again, don’t eat this during a red tide.

Noodles of the sea!

Yes, we’re pretty much the nerdiest nerds you know. Thanks for tolerating my endless seaweed and invertebrate rambling. It’s really amazing how much fascinating stuff there is around, if you just take an hour, slather on the sunscreen, and poke around in wet sand.




Filed under family, summer

3 responses to “Low Tide Redux

  1. Pingback: Still Life with Woodpecker « The Golden Mean

  2. I love this post, great pictures too. Sea creatures are (almost) my favorite.

  3. “…but if you lay the sand dollar cilia down on your palm, it will tickle your hand.”

    I didn’t know that! How neat :)

    And that has to be the cutest crab I’ve ever seen. He’s so sassy!

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