Golden palms

  

Close-up of Sea Palm (Postelsia palmaeformis) blades, 25 June 2025 

Holding fast?

 

 

We were doing surveys during the low tide this morning (27 April 2024) when Eric spotted this unusual interaction.  The holdfast of a small Sea Palm (Postelsia palmaeformis) had grown over and appeared to be attached to a chiton, Nuttallina californica!

 

Chitons are mobile grazers, moving over the surface of the rock and feeding on algae.  Perhaps they take breaks and stay in place for a while, which allowed the kelp to attach to it?

 

We didn't actually pull on the chiton to see if the haptera (root-like outgrowths) were definitely attached to the chiton, but it sure looks like it:

 

 

 

We'll be back in this area and can check on the kelp and chiton again to see how things turn out.

Golden grooves

 

 

Close-up of Sea Palm (Postelsia palmaeformis) blades, 10 June 2023.

 

Taking hold

  

Juvenile Sea Palm (Postelsia palmaeformis) in the rocky intertidal zone on 18 April 2022.

A forest of palms

Wow, the Sea Palm (Postelsia palmaeformis) was really tall in Mendocino County this year!  Here's a photo of Eric making his way through a Sea Palm forest on the way to our study site:

 

 

 

Okay, perhaps you guessed that the Sea Palm isn't really over four feet tall, but it was luxurious up there.  There were lots of nice, extensive patches of this charismatic kelp!

 

Above the fronds

  

Sea Palm (Postelsia palmaeformis) from above, photographed 28 May 2021.

With a little kelp from my friends

 

Last week I went out to check on whether any Sea Palms (Postelsia palmaeformis) were visible yet.  This is when juveniles often appear on wave-exposed rocky shores.  They're very small at this time of year — most of the individuals I saw on 1 February 2018 were under 5 cm (2 inches) tall. Sea Palm is an annual kelp that reaches peak heights (up to 60 cm or 24 inches tall) by summer. 

For comparison, here's an example of a large clump of tall Postelsia washed up on the beach in August (with Eric for scale):

 

Little palms

 

I'm happy to report that Sea Palm (Postelsia palmaeformis) appears to be having a good start to its season...at least in a few locations on Bodega Head.  This photo was taken on 28 January 2017.

As with some other more northern kelps, this species didn't do very well locally during recent warm-water years, so I hope to see more Sea Palm this year!

P.S.  Here's a link to a previous post with some information about Sea Palms.

 

Blue ribbon

Okay, do you remember the mystery photos from last night?

 

Some of you might have noticed in the Comments section that Matt won the prize — he guessed correctly that these patches are dense concentrations of pelagic barnacle cyprids.  Recall that cyprids are the final larval stage that settles out of the plankton.  In this case, these are the cyprids of a pelagic gooseneck barnacle called Lepas sp. 

Here's a close-up of the cyprids under a microscope:

 

After settling on a floating substrate, the cyprids will undergo metamorphosis into juvenile barnacles.  A few of them had already done so:

 

I wanted to post these pictures on the blog because there have been amazing numbers of Lepas cyprids this year — more than any other year since I've been observing floating objects washing ashore in Bodega Bay.  I've wondered if it could be related to the warm water temperatures last year, but we can't be certain.

What's perhaps even more fun, though, is that when I went to take these documentary pictures, I noticed a few other things among the cyprids!

 

At first I thought this was just a blue tentacle (perhaps from Velella)...but then it started moving...and then I noticed the eye spots at the anterior (front) end.  A tiny blue ribbon worm!  I'd never seen a blue ribbon worm before.

One time the ribbon worm left one patch of cyprids and crossed the great divide to another patch of cyprids.  If anyone has thoughts about the identity of this ribbon worm, I'd love to hear more.

 

When I was scanning the cyprids, I also noticed quite a few small light brown spots.  If you look very carefully, you'll see them in the lower left corner of the next photo, nestled among the cyprids:

 

When I zoomed in, I could see that these brown spots were moving, that they had dark eyespots, and that they might have some sort of paired structures forming on their heads (see small bumps in image below).

 

Although I'm uncertain, my best guess for these little brown blobs is that they could be very young pelagic nudibranchs (Fiona pinnata).  I've written about Fiona before (see post on 19 October 2012), but I've never seen one this small, hence my uncertainty.  What do you think?  Do you have a different guess?

The Sea Palm and Lepas cyprids reminded us of a valuable lesson — it's always worth taking a closer look!

Tall ships and small palms

By special request (via Megan), here are two photos of one of the tall ships, the Hawaiian Chieftain, sailing off Bodega Head on 8 April 2012 — one with the ship on the horizon and another zoomed in to see some of the details.

 

 

The tall ships were in Bodega Bay to celebrate the 200th anniversary of Fort Ross where Russians settled in 1812.  Along with establishing the Fort, Russians explored the coast and documented many local species.

One of the most distinctive species collected and described by a naturalist (Ruprecht) associated with Russian expeditions is the Sea Palm (Postelsia palmaeformis).  Bodega Rock, the rocky islet off the southern end of Bodega Head, is the type locality for Sea Palm (the place from which it was collected when first described to science).

In the foreground of the first photo (above) you can see a cluster of Sea Palms on the rocks in the lower right corner.  But this charismatic kelp is worth a closer look.

Here's a group of adults displaying their palm-like appearance.

 

Below is a close-up of a Sea Palm holdfast, the root-like base that attaches the alga to the substrate.

 

Sea Palms are saxicolous (growing on rocks), but are also found attached to animals such as mussels and barnacles, as well as to coralline algae. 

They tend to prefer surf-pounded sites (see below).  Although they can grow up to 60 cm tall, they have a flexible, hollow, cylindrical stipe (or stem) that bends with the waves.

Sea Palms are annuals, reproducing every spring and summer and dying back during the winter. 

Unless you're looking closely, you may miss the very small juveniles that are beginning to grow during the late winter and spring (and occasionally in the fall).  Here are two recent photos of young Sea Palms, one with only two blades (center left), and another that's a bit larger (~2.5 cm high).

 

[If you're wondering, that's a chiton (Nuttallina californica) in the upper right corner.]

 

Fun to think about the connections among tall ships and Russians and Sea Palms!