September star

  

Nice view of a Forbes' Sea Star (Asterias forbesi) in a shallow tidepool in Scituate, Massachusetts, on 20 September 2025.

Eric was able to zoom in for an amazing closeup, too:

 

 

Visible above are short white calcareous spines, the orange madreporite (sometimes called a sieve plate, which is an opening to the water vascular system), and the transparent papulae (finger-like projections involved in gas exchange).  

Thanks for the great photos, Eric!
 

Successs

  

Leaving work tonight (17 September 2025), we noticed a Great Horned Owl (Bubo virginianus) perched on top of a telephone pole.  I turned around and pulled off the road nearby.

We watched for a few minutes and then the owl crouched and took off, gliding down towards the ground:

 

 

 

It landed among the grass, but at first I couldn't tell if it had caught anything:

 

 

  

But then the owl looked up and I could see something in its bill.  This happened quickly, and looking through the camera I couldn't tell what it was, but zooming in later, the prey was visible:

 

 

 

A garter snake!  

It didn't take long for the owl to swallow the snake.  

The next views showed off those large yellow eyes:

 

 

 

 

 

And then the owl flew up to a nearby cypress tree.  The light was just right for a great view of its talons:

 

 

An unexpected encounter!  You never know what you'll see on the way home from work.

Exclamation

  

Designed by sand, water, and air (!)

Layers

   

Close-up of a Red Abalone (Haliotus rufescens) shell, 9 September 2025

ADDENDUM (12 September 2025): There were a couple of requests to show more of the abalone shell.  In this case, the original photo was just a section of the rim of a shell, but here's the photo without any cropping:

 

  

P.S.  Note that I've found that the lighting matters a lot when photographing abalone iridescence.  Overcast days bring out the colors the most. 

At it again

  

There were lots of Humpback Whales visible off Bodega Head tonight (7 September 2025) — mostly spouts, fins, and flukes, but a few breaches, too. 

Marine invertebrate diversity

  

Hi, everyone!  Sorry for the short notice, but if you're interested in learning more about local marine invertebrates, Eric will be giving an online talk for Bay Nature magazine on Wednesday, September 3, from 12-1 p.m. Pacific Time (3-4 p.m. Eastern Time).  

Here's a brief description from the organizers and a link to register:

"Join Bay Nature Magazine and Bodega Marine Lab's Eric Sanford for a virtual talk about tidepool invertebrates of the California coast on September 3, from 12 - 1 pm. Although the vast majority of ocean animals lack a backbone, the diversity of marine invertebrates living in our local waters is often underappreciated. This talk will focus on some of the amazing, beautiful, and mysterious marine invertebrates of the northern California coast. Even popular coastlines are brimming with these intriguing creatures, including species that are new to science. So, tune in to learn more!"

Free for Bay Nature members, $5 for nonmembers.

Click here to register.

 

A slow roll...

  

...into September!

Ready for a dip

  

We paused for a picnic lunch in northern Sonoma County today (30 August 2025) and noticed a very large sea lion on an offshore rock. 

With a closer view, we could see that it was a Steller Sea Lion (Eumetopias jubatus).  Note the paler fur color and the shorter snout (relative to California Sea Lion).

After a few minutes, the sea lion lumbered down the rock face to a low corner.  Note the very long flippers: 

 

 

 

 

 

The sea lion was perched on the edge of the rock, but we sensed that it might not be in that position for very long:

 

 

 

 

I thought the sea lion might continue moving down along the rock towards the edge of the water, but instead it launched (!) off the rock and dove directly into the water:  

 

 

 

Even along the coast today it was warm enough that I considered doing the same thing! 

 

Moon journal

  

Last week I showed a waning crescent, but tonight (26 August 2025) there was a beautiful waxing crescent in the western sky after sunset.

P.S.  Finding the moon on any given day always makes me smile.  Partly because it reminds me that keeping a moon journal was one of my early lessons in making daily natural history observations.  Looking for the moon every day and tracking its phases is a great way to connect to the rhythms of the Earth and the Moon.  If you want to try it, here are some basic guidelines from NASA for a moon observation journal.

A clam like no other

 

 

I looked down to see this distinctive shell washed up at Point Reyes this past weekend (23 August 2025).  Note the elongate shape and the fine ridges radiating from the hinge (the hinge is at the bottom of the photo).

 

I posted briefly about this species back in 2015 (See "File this away" on 28 June 2015), but it's rare to observe Hemphill's File Clam (Limaria hemphilli) in our region, so I thought it would be worth sharing another record.  Limaria hemphilli has a more southern distribution, with most records south of Point Conception (and only a few records north of Monterey).

 

I also remembered that Sam documented a file clam in Bodega Harbor in 2024.  He was lucky to find a live individual and he captured the beautiful and intriguing tentacles.  Check it out!

 

 

 

 

Here's an even closer view of those amazing tentacles:

 

 

 

The tentacles are extensible -- they can stretch out far away from the shell.  And interestingly, there are reports of predators being distracted by tentacles that have been dropped, so at times the tentacles might be used to deter predation (somewhat similar to a lizard's tail).

 

With many thanks to Eric for the photo of the shell and to Sam Briggs for the spectacular photo of the live file clam. 

Multi-porpoise

   

A few quick shots of Harbor Porpoises (Phocoena phocoena) from Limantour Beach on 23 August 2025.

Sea conditions were relatively calm today, making it easier to spot the porpoises.  But it was hard to tell how many were in this group.  Eric and I agree on at least three individuals, but there could have been more.  I wasn't able to photograph more than two at once.

 

 

 

 

 

Classic view of the nice triangular dorsal fin: 

 

 

 

Parade of planets

   

Have you been awake in the early morning this week?  There's a wonderful "parade of planets" visible in the eastern sky.  

Above, the crescent moon with Venus to the far right.  

Below, Jupiter is also visible high in the upper right corner of the photo:

 

 

And here's a close-up of that wonderful crescent moon:

 

 

 

Our view of the eastern horizon is somewhat obscured, but if you live high enough you might be able to add Mercury to the parade in the very early morning hours.

  

Sensory apparatus?

  

Great Horned Owl (Bubo virginianus) perched on an antenna that measures surface currents, 18 August 2025.

P.S.  With thanks to Sam for letting me know about this observation!  

As the world terns

  

Small flock of Caspian Terns (Hydroprogne caspia) and Elegant Terns (Thalasseus elegans) near Drakes Estero this morning (9 August 2025).

There are five Caspians on the left side and one in the far background.  Note their larger size and more robust bills.  Here's a close-up to compare the two species:

 

 

In the photo above there are two Caspian Terns in the foreground on the left side and one Caspian in the background; all of the others are Elegant Terns.  

It's helpful to compare their bills -- the Caspian has a more robust, red bill, with a bit of black towards the tip of the bill.  In contrast, the Elegant has a longer, thinner bill that's often more orange (or yellow) in color, rather than red.  It can also look like it is curved downward because of the shape of the ridge of the upper bill.  

The length and color of Elegant Tern bills vary quite a bit, so here's a close-up of Elegant Terns:

 

 

Tomales Bay reflections

 

 

White Gulch in Tomales Bay with Giant Kelp (Macrocystis pyrifera) reflection, 8 August 2025. 

Bounding

I stepped outside to stretch and to think about a presentation I'll be giving soon, when movement caught my eye.  First, a very small rabbit emerged from the shrubs and went bounding along to the right at a very fast pace and then dove under a different shrub.  Hmmph, I thought, I don't often see Brush Rabbits that small, and it was really moving quickly.  

I had just started to ponder it, but then another movement caught my eye in the first location...a weasel!  The weasel appeared where I had first seen the rabbit, then went bounding along the exact same route, paused, and then dove into the same bush as the rabbit!  Now what was going to happen?  

Out burst the rabbit, running back in the opposite direction (to the left).  And you guessed it, the weasel followed again.  But it didn't seem to know where the rabbit had ended up.  The weasel kept hunting around the bushes, so although I didn't have a camera with me at first, I still managed two quick photos when I returned.  And then both the weasel (and the rabbit) disappeared.  

A few moments of excitement!  It made me laugh a bit, as it was almost like a cartoon...although maybe not as funny for the bunny, although it did escape!  (I'm wondering if this was a juvenile weasel?  It looked a little smaller and paler than usual.)

 

 

 

 

Sailing into August?

  

Just a quick note that there are lots of very large By-the-wind Sailors (Velella velella) washing ashore right now.  Many are in the range of 7-10 cm long.  Photo from 30 July 2025.

From Kamchatka

 

Shown above are the water levels as recorded at the Point Reyes tide gauge on 30 July 2025.  The blue line represents the predicted tide levels.  The red line shows the recorded levels with marked fluctuations,  both higher and lower than the predicted levels, revealing the effects of the Kamchatka tsunami.

 

I posted about the Tonga tsunami back in 2022, so you might have seen a graph like this before.  The basic idea is that the tsunami is a series of water level fluctuations that can continue for hours or days.  The duration of the fluctuations surprised me during the Tohoku tsunami in 2011, but I was ready for them in 2022, and again this time.

 

You can see that most of these water level deviations are less than 1 foot (with an exception at ~3 a.m.).  But the water levels rise and fall very quickly (hence the steep, jagged line).

 

What does this look like in the field?  I've learned that it's easiest to see these tsunami-influenced water levels in Bodega Harbor because the elevation change is so gradual.  It's fairly straightforward to see the water levels rising and falling as the water flows across the mudflats.

 

I only had about an hour this morning, but I took a series of photos between 9-10 a.m. to document the tsunami.  This is a little tricky to describe, but here's the basic scenario of what I captured (below).  It's important to compare the water levels in each photo, especially along the left side of the image. 

 

First photo, 9:02 a.m.  Note the water level on the left side of the photo and where it is relative to the wooden post/sign.
 

 

 

Second photo, 9:25 a.m.  The water has flooded in from the left side and spread across the tidal flats to the right of the sign.  Importantly, low tide was at 9:28 a.m. this morning, so the tide should have been dropping, but the water was rising quickly:

 

 

Third photo, 9:30 a.m.  Only 5 minutes later, the water levels have now dropped back almost to the left of the sign again.  (They should have been rising after the low tide.)

 

 

 

Fourth photo, 9:52 a.m.  About 20 minutes later, the water starts to rise for a second time.  It's spreading to the right of the sign again:

 

 

 

Fifth and sixth photos, 9:58 a.m. and 10:08 a.m.  Although the tide should be coming in at this point, the water levels are dropping again.  They are receding to the left of the sign:

 

 

 

 

 

 

Seventh and eighth photos, 10:12 a.m. and 10:16 a.m.  Only four minutes later, the water levels are rising for a third time within a 75-minute period:

 

 

 

 

 

 

I think the area in the green box below shows the period when I took these photos:

 

 

It'll be interesting to see how long the water level fluctuations continue.  You can check the Point Reyes tide gauge yourself here.

 

Amazing to see how these waves cross the entire Pacific Ocean basin!  

 

P.S.  I'm thankful to NOAA for maintaining these tide gauges and helping us understand this phenomenon.

 

Swimming north rapidly

  

This was a little unexpected, but as I was watching the Humpback Whales yesterday (26 July 2025), I caught a glimpse of a fin much closer to shore and realized it was a Bottlenose Dolphin (Tursiops truncatus).

I wasn't quite ready and didn't get a great photo, but I thought one photo was possibly good enough to identify the individual.  So I sent it off to Bill Keener at The Marine Mammal Center.  Sure enough, Bill was able to match this to a known female in their catalog.  "Cepat" has been seen in Sonoma County before, and as far north as Sea Ranch. 

Here's a few of her heading north:

 

 

By the way, Bill mentioned that Cepat doesn't usually travel alone, so it's a good time to keep an eye out for other Bottlenose Dolphins in the Bodega Bay area.  Let us know if you see any!  

P.S.  I was curious about the name "Cepat," so I looked it up.  Sounds like it's an Indonesian word meaning rapid, quick, or swift.

P.P.S.  Many thanks to Bill for providing the background information about Cepat and for monitoring local marine mammals!

ADDENDUM (31 July 2025): Some people have inquired about how Bill identified Cepat.  Individual Bottlenose Dolphins have distinctive markings on or near their dorsal fins.  So if you get a good enough photo and the dolphin is a known individual in the photo catalog, you can match the markings.  Here's a close-up where you can see a couple of distinctive notches at the base of Cepat's fin: