Kelp toes

  

Tiny little kelp toes -- close-up of a Bull Kelp (Nereocystis luetkeana) holdfast attached to a rock.  Washed ashore in Bodega Bay on 27 July 2024.

A bigger anchor

 

 

I was leading a walk about seaweeds today and we encountered a few of these Bull Kelp (Nereocystis luetkeana) holdfasts attached to small rocks.  The rocks likely served as anchors when the kelp was small, but once they grew larger these rocks just weren't heavy enough to keep the kelp in place.

 

 

 

Fun to see the little kelp "feet," but maybe next time the microscopic stage of the kelp will find a larger rock.  You know the famous quote, "You're gonna need a bigger boat anchor."  ;)

Before the split

  

Always fun to see juvenile Bull Kelp (Nereocystis luetkeana).  This one was photographed a few days ago on 12 August 2023.  The blades haven't quite split apart yet, but you can see where that will happen.

Floats and blades

  

I'm getting ready to talk with some students about local kelps, so here's a photo of Bull Kelp (Nereocystis luetkeana) from June 2022.

At the surface

  

A nice patch of Bull Kelp (Nereocystis luetkeana) close to shore, 16 June 2022

Washing in with the waves

  

A tangle of Bull Kelp (Nereocystis luetkeana) washed ashore after high winds and waves this past weekend.

 

Fog and morning light

  

 

Interesting light with fog over the ocean this morning, 29 October 2020.

[You can click on the images for larger versions.]

 

 

 

Local patches

  

Recently, several people have asked me about the kelp beds that are visible just offshore of Bodega Head right now.  The calm ocean conditions and gray overcast days during the second half of July have helped make these Bull Kelp (Nereocystis luetkeana) patches stand out.

Most people in this area have heard about the significant declines of kelp beds throughout Sonoma and Mendocino counties during the last five years or so.  However, the kelp beds off Bodega Head are a bit of a puzzle.  These local patches of kelp have increased in number and extent during the last ten years, and that has become especially apparent during the last five years.

For the record, I started taking photos of some of the local Bull Kelp patches back in 2008.  As an example, here's one from 2016.  [Look for the darker blue/brown area in the water just beyond the shoreline.]

 

I'm not sure why the kelp beds off Bodega Head have increased while those at many other sites have decreased.  I have wondered if there might be some connection to more rock being exposed on the bottom (where kelp can take hold) if sand shifts during significant wave events (e.g., during the 2015-2016 El Niño).  But there are lots of other factors that could influence the success of the kelp here, e.g., water temperatures, nutrients, dispersal of spores, grazers, etc.  The reasons might remain a mystery, but the expansion of the local Nereocystis patches has been interesting to watch and raises many questions.

 

Enlightening

 

Wonderful morning light showing the sori (patches of spores) on a large blade of Bull Kelp (Nereocystis luetkeana).

The next photo reveals even more of the blade.  I'm curious about the darker and lighter colors of the two different patches (upper and lower) and wonder if they represent stages of spore maturity?  Perhaps someone out there can help?

 

Little floats

 

Some juvenile Bull Kelp (Nereocystis luetkeana) has been washing ashore recently (photo above from 27 July 2019).  It made me wonder — What's the smallest Bull Kelp I've photographed?

Here's one from August 2016 that's a fairly similar size to the one pictured above. (Although there's a very small individual that doesn't have a float yet hiding behind Eric's finger.)

 

And here's one from May 2012 that was growing in a tidepool in Mendocino County.  The float wasn't fully formed yet, and the blades attached to the float hadn't split:

 

I'll have to keep better track of the young individuals.  What's the smallest Bull Kelp float you've seen?

Kelp!

 

An amazing amount of Giant Kelp (Macrocystis pyrifera) washed up on local beaches during the last two days.  Although abundant in the Monterey area, Giant Kelp is less common in Bodega Bay.  I don't think I've ever seen this much Macrocystis on beaches in Bodega Bay (during the last 12 years).

The photo above shows the rippled or corrugated blades of Giant Kelp.

Below, note its relatively loose and sprawling holdfast (the portion of the kelp that attaches to the substrate):

 

(Why is the holdfast purple?  Maybe someone out there can provide some ideas?)

There was some large Bull Kelp (Nereocystis luetkeana) mixed in with the Giant Kelp.  Bull Kelp is the more common large kelp in our area.  In the photo below, the Bull Kelp is tangled up with the Giant Kelp, but you'll recognize Bull Kelp's very large float (pneumatocyst) and the smooth and shiny blades (the Bull Kelp blades also lighter in color than the Giant Kelp blades):

 

Here's a photo comparing the holdfasts of the two species:

 

The Giant Kelp holdfast is on the left and the Bull Kelp holdfast is on the right. 

I had wondered if this kelp might have been ripped out by the powerful 20-21 January storm, but upon closer inspection, I noticed quite a few pelagic barnacles (Lepas sp.) attached to the kelp, indicating it had been at sea for quite some time.  [There's a lot going on in this photo, so I've highlighted a good example of a pelagic barnacle with a circle.]

 

Based on the amount of kelp, its age, and strong recent currents from the south, I'm still guessing that this Giant Kelp originated from sites to our south.  But I'm not sure why so much has arrived on our beaches!  (Let me know if you have some ideas!)