A sunset along a rocky shoreline.

What’s in the Tidepools? – March 2021

What’s In the Tidepools? – March 2021

Our dedicated volunteers at Cabrillo National Monument take photos of the exciting flora and fauna down in the tidepools! We want to try and capture the wonderful photos that volunteers are taking in the tidepool area. This blog post will get published on a monthly basis, but we need your help. We encourage you to contribute by submitting your memorable photos and/or short videos to cnmvipvoice@gmail.com. These can be of tidepool critters, fauna, bluff collapses, sunsets or anything you consider special. Make sure you include who took the photo and the location, if possible. Will you help?

Here are some highlights from this month!

This Swell Shark egg sack, also known as a Mermaid’s Purse, is found quite frequently in the tidepools. The hook at the top is used to attach to kelp. Once the shark hatches, this egg sack washes up into the tidepools.

A black plastic like flat oval on rocks. A holr is at one end of the oval.
NPS Photo/P. Geisler

While normally spotted in the kelp forests offshore while scuba diving, Purple Sea Urchins are considered rare in the tidepools. They are generally found underneath rocks submerged in water, or in deep pools only accessed on days with very low tides.

A spherical purple ball with cylindrical purple spikes all over it.
NPS Photo/P. Geisler
A black blob is attached to a rock. A tan oval shaped hard shell sits on top of the blob. The shell has an opening in the middle.
NPS Photo/N. Cheng

Giant Keyhole Limpets can grow up to hand-size in diameter. They release waste through the top of their shell, and are known in the medical field for their blood and use of it in vaccines. Ranger Lauren thought that the damage to the limpet’s shell on the right might have been caused by a crab or bird.  She also said it would not be able to repair the damage.

A hand sized, oval shaped gray blob with a smaller oval shaped hard shell on top. There is a hole in the center of the shell. The shell appears to be damaged from a bird pecking at it.
NPS Photo/M. Rose

California Sea Hares are commonly encountered in the tidepools. Although it doesn’t seem like it, this one was almost 10 inches long!

NPS Video/N. Cheng
A hand shows a hot pink penny sized blob with pink cylindrical tubes on seaweed.
NPS Photo/N. Cheng

Many TPERP volunteers have reported seeing an increased number of Hopkin’s Rose nudibranchs scattered throughout the tidepools.

Two fingernail sized hot pink blobs with cylindrical spikes on a rock, six feet apart.
NPS Photo/P. Geisler

Socially distant Hopkin’s Rose Nudibranchs! However, we don’t see their masks.

Spanish Shawls belong to the nudibranch family. As you can see here, they are spectacularly colored with a blue-purple body and bright orange appendages called cerata. They move by flexing their body in a signature “S” shape.

A purple cylinder with orange spikes on long green blades of grass.
NPS Photo/N. Cheng

Large gray and white bird flying overhead with fish in claws
NPS Photo/P. Geisler

A beautiful osprey with fish in its talons. Ospreys hunt for fish and other prey by diving between 30 and 100 feet to the ocean surface. Lunch anyone?

The bone of a seal is held by a person along a rocky beach next to sandstone cliffs
NPS Photo/J. Hunt

It’s that exciting time of year when both seals and sea lions are having their pups! However, as nature often takes it course, some of them do die and wash up on the beach. These are remnants of a sea lion that was found near the Zone 1/2 boundary. Other bones of sea lions have been found, as well as a couple of dead cormorants as well.

Several vertebrae held in a hand
NPS Photo/P. Geisler

An animal footprint along the Coastal Trail. Could it be from our elusive Gray Fox? Has anyone seen signs of the fox since the park reopened?

Animal footprint in sand along with human show prints.
NPS Photo/D. Lee
A reddish orange finger sized elongated blob on seaweed. A walking stick is to the left of the blob.
NPS Photo/J. Hunt

Sponges are the most primitive of the multicellular animals, and not algae as one might think. They can be found in various shades of yellow, red, blue, white or black. They are irregular in shape and often hard to identify, but still cool to find.

A thumb sized sea slug with two antenna and orange cylindrical spikes on it's back.
NPS Photo/N. Cheng

Here’s another species of nudibranch. We’re not sure if this is an Opalescent Nudibranch(?) or a different variety. It was approximately an inch long and found in the shallow pools close to the entrance. If you have any thoughts, leave a comment below.

A foot sized purple and black blob moves in shallow water.
NPS Photo/P. Geisler

Another cute California Sea Hare. They are so fun to watch move around eating the algae. Be on the lookout for their eggs when you are exploring. The eggs look like a blob of spaghetti.

Woman holding plastic tripod against rocks on rocky beach
NPS Photo

Kids have the best quotes – We just couldn’t pass this one up. TPERP Brian overheard the following conversation during a recent shift. We’ll let him describe what he heard.

As you know, sometimes during a TPERP shift we hear the darndest things. Last Sunday I had completed a morning roving shift and had walked up to the TPERP trailer to have a snack before returning for an afternoon Tide Pool shift. I took my snack from my pack in the trailer and walked over to the ocean side of the trailer to enjoy the view as I took a break. While there I heard a boys voice, maybe 13 years old, say to his mom “Mom look, she’s using a walker” I turned to see the boy and his Mom looking at the wayside picture of Ranger Bonnie using the PVC pipe photo plot monitoring tool. Before I could go back into the trailer to retrieve my face covering to try and provide an “Educational Interaction” as to what exactly Bonnie was doing in the photo they were down the trail. After finishing my snack and heading back to the tide pools I stopped and looked at the photo and thought, yeah I guess I can see how maybe he might draw that conclusion, but they sure didn’t take into account that the Ranger in the photo was not nearly at a stage where a walker might be needed.

A rocky beach next to sandstone cliffs in the afternoon.
NPS Photo/P. Geisler
A rocky beach along sandstone cliffs. Gray clouds overshadow the view.
NPS Photo/D. Lee

Another perfect day at the tidepools. Does it get any better than this?

3 thoughts on “What’s in the Tidepools? – March 2021

  1. herb ochitill
    3:49 PM (1 minute ago)
    to comment+cybi5m1he1eiljp4ge4x0ucn, Karyn

    Dear blog poster, a volunteer & family member kindly shared the set of photos of marine animals to be found at Cabrillo. I found the images intriguing & varied examples of the life that abounds along our coastline.

    There was one image that was less welcome – that of the purple sea urchin. As you may know, rising ocean temperatures have promoted bacterial growth that seems the source of sea star wasting disease. Without these predators of the urchins, the urchin population has exploded & with it the devastation of the kelp forests of northern Cal.

    Sadly, it seems likely that growing climate change will increase its impact on the delicate equilibria of nature.
    Herb Ochitill

  2. The nudibranch with orange coloring is not an opalescent (wrong coloring). It’s anteaeolidiella oliviae, or Olive’s Aeolid (confirmed on iNaturalist). We think the sea urchin is actually a red sea urchin. Happy Tide Pooling! Warren & Jackie

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