Category: General natural history

Six months, and a big return

Posted on by Allison J. Gong

Next week I will be six months beyond a total replacement of my right knee. The rehab has been long and tough, and I’m nowhere near the end yet. I’ve been told by my surgeon to expect a 12- to 18-month recovery to get back to whatever my new normal will be. By that estimate I’m either 1/3 or 1/2 of the way there; given the way things are going I suspect it’s the smaller fraction, so I’m looking at another year of ongoing, slow improvement.

I’ve finally gotten strong enough that I felt ready to return to the intertidal. And yesterday being the first day of a new year, it seemed fitting to venture out into my old life again. I chose a site that didn’t involve any cliff-climbing (not quite up to that yet), but did have stairs so I could challenge the knee. Down is still hard, but up is a piece of cake now.

Two people standing among dark rocks. Person in the front is wearing a bright pink jacket and holding a green rectangular object. Person in the midground is wearing a black jacket and green knee-high boots. There is a lighthouse in the background.
My friend, Sara, and me on the rocks at Whaler’s Cove
2026-01-01
© Alex Johnson

It was great getting out to the intertidal and seeing some of my old friends again! January isn’t the best month to find happy algae, but the rockweeds were already recruiting and growing. Here’s a baby rockweed, probably Pelvetiopsis limitata (they can be hard to ID as youngsters):

Olive-green ribbon-like structure with bifurcated tips emerging from wiry dark red threads
Baby rockweed, probably Pelvetiopsis limitata, in a thicket of Endocladia muricata
2026-01-01
© Allison J. Gong

And there were some lovely stands of Fucus:

Bunches of flattened dichotomously branching algae, olive-green in color, on rocks
Thalli of the rockweed Fucus distichus
2026-01-01
©️ Allison J. Gong

Note that the tips of the Fucus branches are flattened. These are young thalli. In the summer, mature thalli will have swollen tips full of gametes. Fucus, and the rockweeds in general, have what we call an “animal-like” life cycle instead of the alternation of generations that is more typical of seaweeds. And we won’t even get into the complexity of the alternation of three generations in some of the reds! So yes, Fucus thalli come in male and female forms that produce sperm and eggs, respectively. Sounds familiar, doesn’t it?

We saw several ochre stars, none of which were ochre in color. And now that I think about it, I see many more P. ochraceus that are purple, red, or orange than are ochre.

Dark purple star-shaped animal attached to a rock
Ochre star (Pisaster ochraceus)
2026-01-01
© Allison J. Gong
Bright orange star-shaped animal stuck to a rock
Ochre star (Pisaster ochraceus)
2026-01-01
© Allison J. Gong

And lest we forget, Sea Star Wasting Syndrome (SSWS) hasn’t been banished from the world. I suspect it will always be around but won’t always be as prominent as it was 10 years ago. Yesterday we saw two disembodied arms of a purple Pisaster ochraceus. The rest of the body was nowhere to be found, and I guess this star dismembered itself a couple of days ago.

Two approximately triangular structures on a sandy background with two large rocks and a snail shell
Disembodied arms of Pisaster ochraceus in a tidepool
2026-01-01
© Allison J. Gong

On a much more pleasant topic, I noticed a pattern of different organisms lined up in rows.

Row 1: Limpet scars. These ovoid blotches are the scars made by a limpet, Discurria (formerly Lottia) insessa. The limpet lives on the stipe of feather boa kelp (Egregia menziesii), shown below. It eats the algal film that accumulates on the kelp but eventually ends up chewing through the stipe, which then breaks. They literally eat themselves out of house and home, poor guys.

Long brown strap running horizontally across the image. There are eight golden ovals along the length of the strap.
Limpet scars on stipe of Egregia menziesii
2026-01-01
© Allison J. Gong

Row 2: Anemones. Many intertidal animals (and algae, for that matter) settle preferentially in cracks and crevices. These are the places that hold water the longest at low tide, giving the organisms a slight bit of protection against desiccation. For the same reason many organisms prefer to settle on vertical rather than horizontal surfaces. I found this group of anemones in an almost-straight line in a shallow indentation in the rock.

Five roughly circular objects arranged approximately vertically against a pink background
Row of anemones (Anthopleura spp.)
2026-01-01
© Allison J. Gong

Row 3: Anemones. In geometry, two points define a line. So I can claim that these two anemones make a row! You may have to look carefully to see the second anemone.

Circular object with white protruding tentacles radiating from center. To the right, a similar object with transparent tentacles.
Moonglow anemones (Anthopleura artemisia)
2026-01-01
© Allison J. Gong

These are the same species. Anthopleura artemisia is highly variable, more so than the other species in the genus. The tentacles can be a solid opaque color, as in the animal on the left, or transparent/translucent with or without opaque patches, as in the anemone on the right. They tend to live in sandy areas and often have sand covering the oral disc. If disturbed they will retract into the sand and disappear.

Beach landscape. Large boulders covered with brown/reddish algae or green plant growth, on sandy bottom. Gray cloudy sky above greenish water.
Scenery at Whaler’s Cove
2026-01-01
© Allison J. Gong

All in all it was a fantastic re-entry into the rocky intertidal. My body remembered how to move around, my balance was not entirely shot to hell, and my knee did fine. I was able to forget about it and just use it like a normal person would. When I started physical therapy I told the therapists that one of the things I need to be able to do was work in the rocky intertidal. They were skeptical at first, because they envisioned me jumping from slippery rock to slippery rock. I had to explain that I’m very safety conscious in the field and know all the tricks of an old-timer: Keep your body low (so you have less distance to fall) and keep three of the five points of contact (two hands, two feet, and one butt) with the rock at all times.

I’m calling this a major milestone achieved, even if I still have a long way to go. Yippee!

Spying on the hunter

Posted on by Allison J. Gong

This afternoon I was hanging some laundry to dry on the back deck, when something reddish caught my eye. I grabbed the binoculars, peered down into the bushes, and saw a pair of ears emerging from behind a bush. Soon a very handsome coyote came out to bask in the sun. Just in case it did anything interesting I fetched the camera, which was fortunately already wearing the 400mm lens, and settled down to watch for a while.

After a few more moments enjoying the sun, the coyote got up and went on alert. It had clearly heard something. A late lunch, maybe?

Reddish-brown doglike animal with large ears standing on hillside and looking off to its right
Coyote (Canis latrans)
2025-01-15
© Allison J. Gong

Yes indeed, the hunt was on!

Reddish-brown doglike animal facing to the right with its head at ground level behind some tall grass
Coyote (Canis latrans)
2025-01-15
© Allison J. Gong

It didn’t take long for the hunter to make its catch.

Reddish-brown doglike animal with large ears turning to face left and carrying a gray object in its mouth
Coyote (Canis latrans) carrying a rodent in its mouth
2025-01-15
© Allison J. Gong
Reddish-brown doglike animal with large ears facing the left and carrying a gray object in its mouth
Coyote (Canis latrans) carrying a rodent in its mouth
2025-01-15
© Allison J. Gong

But in the manner of a cat, the coyote dropped the rodent and played with it for a while.

Once the rodent (which I think was a rat of some kind) was captured, it took more chomping than I had anticipated for the coyote to actually eat it. I kept thinking, “Okay, it must be done now,” and the coyote would turn its head to show me the rodent sticking out of the side of its mouth.

The entire event, from when the coyote first heard the rustling of the rodent to when it stood up and walked away, lasted about five minutes. Shortly after finishing its meal the coyote stood up, threw a glance down the hill, and disappeared into the bushes.

Reddish-brown doglike animal with large ears standing on hillside and looking off to its right
Coyote (Canis latrans)
2025-01-15
© Allison J. Gong

We often hear coyotes yipping at night, which inevitably riles up all the neighborhood dogs, and occasionally we capture one on the critter cam. It’s not unusual to see coyotes in the daylight, but this is the first time I’ve gotten to see one hunting and making a kill. This coyote looked very healthy. And this is why we keep the cats indoors!

Collateral damage

Posted on by Allison J. Gong

My home town of Santa Cruz made national news the other day, 23 December 2024, when a series of massive swells caused part of the Municipal Wharf to collapse into the ocean. People in the restaurants and other businesses had to evacuate immediately, and three people were dropped into the water of Monterey Bay (they were all rescued safely and no human lives were lost). The bathroom building fell into the water and washed up on the beach at the mouth of the San Lorenzo River. Almost immediately, memes appeared, advertising a 2-bathroom unit with both river and ocean views, renting for $6000/month. Given the exorbitant rents here, you could argue that maybe this is a pretty good deal.

That afternoon, the same swell tore through the Santa Cruz Small Craft Harbor and replicated the damage done by the Fukushima tsunami in March 2011. The damaged docks had been replaced in 2014, but this recent damage ripped them up again. Boats and docks were thrown around and crashed into each other. An unknown amount of diesel fuel and gasoline were also “liberated” into the water.

My friend Murray has a little boat, Scherzo, that lives in the upper harbor on G dock. On the day of the worst swell, Murray had gone down to see how Scherzo was faring. At that point she had taken at least some cosmetic damage to her paint but didn’t seem to be taking on any water except rain water. The harbor patrol had closed all of the docks so he couldn’t get close enough to see if there were worse injuries. At one point another boat had come down the channel and gotten wedged under Scherzo so she was floating on top of it. Somebody rescued Scherzo and tied her up at a spot just under the ramp from her usual berth. Yesterday, Christmas Day, Murray called us to say that he was down at the boat and asked if Alex (my husband) could help him get her out of the water, as more big swells were forecast. I’m not very useful when it comes to boats, but I went along to watch things from above and hold lines and such.

Before they could take Scherzo out of the water, they had to make sure she was seaworthy enough to be driven down to the boat ramp at the lower harbor.

Dock with two large boats tied up on one side and one small boat tied up on the other side. One person in the small boat. One person crouching on the dock next to the small boat
Murray and Alex give Scherzo a check-up
2024-12-25
© Allison J. Gong

Behind Murray, who is wearing the pink cap, you can see damage to the finger dock. And notice that the big boats aren’t sitting straight in their slips. Scherzo‘s usual spot is on the other side of the ramp; she got pushed under the ramp and a kind soul tied her up here.

This is the capsized boat that had gotten wedged under Scherzo. It was now stuck under the ramp, just in front of Scherzo‘s spot.

Capsized boat wedged under a pedestrian bridge
Capsized boat under ramp
2024-12-25
© Allison J. Gong

Scherzo‘s engine started right up, and the boat itself having been deemed safe to drive by Alex the Engineer, Murray took her down the harbor slowly. Alex and I met him at the boat ramp.

While we were waiting, we noticed that some of the pilings from the busted-up Wharf, which is more correctly a pier rather than a wharf, had been hauled out of the water and set in the parking lot.

Wharf pilings in the harbor parking lot
2024-12-25
© Allison J. Gong

Knowing that the biota on the pilings would be very similar to the critters I see in the rocky intertidal, I had to investigate. And it was very sad. Most of the animals had died waiting for a high tide that wouldn’t return. Some of the barnacles were still alive, albeit just barely so.

Log lying on pavement, covered with small pink blobs and large brown objects also covered with small pink blobs.
Large barnacles (Balanus nubilus) and pink corallimorpharians (Corynactis californica)
2024-12-25
© Allison J. Gong

Here’s a close-up shot of one of the big barnacles encrusted with other animals:

Beige pyramid-shaped structure with pink blobs on the lower surfaces
Large barnacle (Balanus nubilus) and pink corallimorpharians (Corynactis californica)
2024-12-25
© Allison J. Gong

There were many empty worm tubes, former homes of the beautiful Eudistylia polymorpha. I saw one dead worm that had fallen out of its tube:

De-tubed feather duster worm, Eudistylia polymorpha
2024-12-25
© Allison J. Gong

One of the rocky intertidal denizens, the pink barnacle Tetraclita rubescens, was there, too:

Pink barnacle (Tetraclita rubescens) with smaller barnacles (Balanus glandula) and mussel byssal threads
2024-12-25
© Allison J. Gong

To get a feel for how big Balanus nubilus and Tetraclita rubescens are, my left index fingernail measures exactly 10 mm across. That B. nubilus is a big sucker!

Large volcano-shaped structure with two smaller pink volcano-shaped structures on the side. Finger for size reference
Balanus nubilus and Tetraclita rubescens
2024-12-25
© Allison J. Gong

Balanus nubilus is a strictly subtidal species that I never see in the intertidal. Tetraclita rubescens occurs in both the intertidal and the subtidal; some of these subtidal specimens were larger than the ones I see in the intertidal. Most sessile marine invertebrates can feed only when they are covered by water, which means that the ones living in the intertidal don’t feed at low tide. Thus the subtidal T. rubescens can get larger than their intertidal conspecifics, simply because they can feed 24/7. We see the same pattern with mussels in the intertidal: those higher up in the mussels’ range are smaller than the ones in the lower part of the range.

Some of the barnacles were still alive. They can close up their shells and wait out a low tide. But sitting out of the water for longer than a day was more than even they could withstand.

Other old friends were there, including many sea anemones. This is the sunburst anemone, Anthopleura sola, looking the way it does when I see it in the intertidal at low tide.

Cylindrical animal hanging down from vertical surface
Sunburst anemone (Anthopleura sola)
2024-12-25
© Allison J. Gong

Other anemones had been caught in the act of dividing. These would be the cloning anemones, Anthopleura elegantissima.


2024-12-25
© Allison J. Gong

2024-12-25
© Allison J. Gong

Probably the saddest thing was a desiccated red octopus on the pavement. It had probably plopped out of a nook and tried to make its way back to water. Poor little thing.

Grayish-brown lump with suckered arms
Red octopus (Octopus rubescens)
2024-12-25
© Allison J. Gong

The organisms on these pilings were caught in their final moments of life, just as the citizens of Pompeii and Herculaneum were when Mt. Vesuvius erupted in 79 AD. Some of them had tried to escape (the octopus) and some were not quite dead yet (the barnacles), but the inevitable is well, inevitable. At some point the pilings will be removed to the landfill. The same thing happened when the harbor docks were replaced in 2014. I happened to be there with a class and we saw all of the old docks piled up in the parking lot, with all of the attached biota slowly drying up in the sun.

So while there will be reports in the coming days about how many millions of dollars it will take to rebuild the harbor (again) and the pier, let’s not forget that there were other losses that cannot be assigned a dollar value. There is also a potentially major ecological impact of new (again) harbor docks. When the old docks were removed in 2014, they had been covered with a decades-old fouling community. The new docks were pristine new habitat for recruits, and shortly after they were put in I noticed an invasive brown alga, Undaria pinnatifida, which I hadn’t seen before. Undaria is a western North Pacific edible seaweed that is known culinarily as wakame. In recent years it has become one of the most abundant macroalgae in the lower areas of the harbor. The docks that were destroyed this week had been in place for only 10 years or so, and it will be interesting to see how primary succession occurs when new docks are installed. Hmm, that sounds like something I can have my Ecology students document and monitor!

Appreciating the tinies

Posted on by Allison J. Gong

Earlier this week I collected a plankton sample and settled down for a day of microscopy. For a variety of reasons it was my first foray into actual biology for the month of June, and I just wanted to feel like a marine biologist for a while.

As far as plankton samples go, there wasn’t a lot to write home about. The large centric diatoms that we had seen in the spring were much less abundant, although there was quite a bit of the pennate diatom Pseudonitzschia. Part of the reason I did the plankton tow was to have something to look at under the microscope and to practice taking photos. There are all sorts of gadgets that allow one to use a phone to take photos through the microscope, but I’ve found those to be either specific to one phone model or too fiddly and frustrating to get properly lined up. Besides, when I bought my microscope several years ago now I had the foresight to splurge for the trinocular head, which allows me to mount a real camera and leaves both eyepieces available to look through. Might as well take advantage of it!

So, I just took a bunch of photos.

First up was a chain diatom in the genus Chaetoceros. Phase contrast lighting might not have been the best option here, but oh well. Chaetoceros cells are box-shaped, with a spine protruding from each corner of the box. Aside: ‘chaeto’ means ‘hair’ or ‘bristle’ in Greek. The spines of adjacent cells sort of interlock and hold the cells together, forming the chain. Spines also provide some defense against predation.

Many species of Chaetoceros form straight chains like this.

Chain diatom Chaetoceros sp., viewed with phase contrast lighting
2024-06-24
©Allison J. Gong

But one species, Chaetoceros debilis, forms spiral chains!

Spiral chain of gold-colored boxes
Chain diatom Chaetoceros debilis, viewed with brightfield lighting
2024-06-24
©Allison J. Gong

Earlier in the spring there were a lot of Coscinodiscus diatoms in the local plankton. Those are the big button-like diatoms with the sculpted frustule. They aren’t nearly as common now, but I did see a few. And managed to get a nice shot of one:

Golden circular object

The star of the show was Thalassiothrix, another diatom in which the ends of cells cells remain connected after dividing. Instead of forming chains as Chaetoceros does, Thalassiothrix makes colonies that are either zig-zag or star-shaped. It just so happens that this organism looks especially brilliant under darkfield lighting, so I was very happy.

Diatom Thalassiothrix sp, viewed under darkfield lighting
2024-06-24
©Allison J. Gong

But take a look at this symmetry:

Fan-shaped arrangement of long golden rectangles, against a black background
Diatom Thalassiothrix sp, viewed under darkfield lighting
2024-06-24
©Allison J. Gong

Isn’t that a spectacular organism? I had a lot of fun developing and processing that image, and am happy at how well it turned out. Darkfield lighting is fun to play with!

An inadvertent voyeur

Posted on by Allison J. Gong

A week ago I was with a group of students at Moss Landing, where we spent a couple of hours watching birds on our way down to Fort Ord Natural Reserve for an overnight camping trip. The visit was well-timed: we arrived at low tide so there was a lot of mud flat exposed, meaning ample real estate for foraging shorebirds. By now the students were pretty comfortable using binoculars, and it warmed my heart to see them getting used to one of my favorite tools in the naturalist’s kit.

Two people wearing jackets and backpacks, sitting on a log facing away from the camera. They are looking through binoculars at the ocean.
Students observing birds at Moss Landing State Beach
2023-02-11
© Allison J. Gong

The real stars of this particular tale were the birds. Specifically, a pair of willets (Tringa semipalmata). As we walked along the road towards the dunes and beach, I caught sight of a pair of willets involved in what appeared to be an altercation of sorts. I snapped off a bunch of photos and continued on.

When I had time to review the photos a few days later, I saw that what I had thought was some display of aggression was actual mating, or preliminary activities to actual mating. Oops! That hadn’t occurred to me at the time because somewhere in the back of my brain I thought that willets are winter visitors here who breed elsewhere. Of course, courtship and pair-bonding involve multiple bouts of copulation, and any single copulation event may or may not result in successful insemination. It does make sense for copulation to occur before migration to breeding grounds, whether the “real thing” happens here or in the birds’ summer range.

All this to say that I captured a series of photographs that, if they were of our species, would be considered pornographic. But since the subjects were willets and not humans, I can call them wildlife photography!

This is a series of 21 photos, presented as a slide show. The entire sequence of events took about 10 seconds.

I didn’t catch the exact moment of cloacal contact, if indeed there was any. It does still feel a little bit voyeuristic, but that’s why I like watching birds in the first place—they carry on their lives and don’t care about human morals or pruderies. It is always an honor and a privilege to witness nature doing its thing. And who knows, perhaps a new generation of willets was conceived by this pair!

The odd couple

Posted on by Allison J. Gong

Today my co-teacher, Gabe, and I took our Ecology students up the coast a bit for the first field trip of the semester. We spent the morning at the bottom of Big Basin State Park, where we did a little walking and a lot of looking and talking. In 2.5 hours we traveled maybe a mile, which is the appropriate pace for studying nature.

Man showing a group of people an object in his hand.
Gabe telling students about the habits of newts (Taricha torosa)
2023-02-03
© Allison J. Gong

Much of this area burned in the CZU Lightning Complex fires of 2020. That was 2.5 years ago now, and a lot of vegetation has returned. My favorite thing to see was the lace lichen, Ramalina menziesii. It drapes over plants and has a special affinity for the coast live oak Quercus agrifolia, just like I do. I was very happy to see a lot of new growth in the lichen, all spring green and fresh.

Pale green threads draped over tree branches, forming lacy network
Lace lichen (Ramalina menziesii)
2023-02-03
© Allison J. Gong

See how pretty it is?

Pale green threads draped over a tree branch
Lace lichen (Ramalina menziesii)
2023-02-03
© Allison J. Gong

After lunch we crossed the highway and went down to Waddell Beach. The tide had receded and we could see that a tremendous amount of sand had been washed away by the storms, leaving exposed rocks that were usually covered. Students found all sort of interesting rocks, including fossils. We also found several sand dollars, a few of which hadn’t been broken.

This was one of my favorite finds:

It’s the test of the sand dollar Dendraster excentricus. In life, sand dollars are a purplish gray color, covered with apparent fuzz that consists of short spines. I’ve seen sand dollars described as gray shag carpets, and that’s actually not too far off. When the animal dies the spines and living tissue erode away from the test, leaving behind the white calcium carbonate.

Okay, but what’s that round black spot? That’s the super cool thing.

It just so happens that there’s a barnacle, Paraconcavus pacificus, that attaches to sand dollars. It lives on other hard surfaces, too, but the fact that it lives on sand dollars buried in the sand brings to mind all sorts of questions.

Round, flat gray object lying on sand. A volcano-shaped shell is attached to the round object.
Dead barnacles (Paraconcavus pacificus) on the test of a sand dollar (Dendraster excentricus)
2023-02-03
© Allison J. Gong

Question #1: How does the barnacle’s cyprid larva find a host? My best guess is that the cyprid locates a sand dollar by scent. Sand dollars live partially buried in sand, like tortilla chips in guacamole. Enough of the sand dollar protrudes from the sand to provide plenty of real estate for home-hunting cyprids.

Question #2: What happens to the barnacle if the sand dollar gets completely buried? Well, this I don’t know. A barnacle buried in sand cannot feed. But if the barnacle is attached to the part of the sand dollar that is always (or almost always) sticking out of the sand, then the barnacle could feed perfectly well. Which brings me to . . .

Question #3: Do the barnacles always attach to the same part of the sand dollar? The answer to this question is “Yes”, because sand dollars bury themselves with the “posterior” part sticking up. Yes, it’s hard to talk about anterior and posterior in an animal with pentaradial symmetry, but sand dollars do crawl across the sand in one direction, which defines “anterior” even though the animal doesn’t have a head. Since the sand dollars bury their anterior edge, barnacle cyprids have access only to the posterior edge.

Which in turn explains why the sand dollars with barnacles have barnacles at the bottom of the petaloid, the bit that looks like a 5-petaled flower. That’s the posterior area.

Question #4: Does the weight of the barnacle affect the sand dollar, perhaps by making it top heavy? I can’t imagine that it doesn’t have some effect on the sand dollar. A barnacle is a pretty hefty object, after all. But I can’t find any research about these barnacles and their strange habits.

Returning to that black patch on the test above, now. That’s the scar left behind by a barnacle that used to live on that sand dollar. I have no way of knowing whether the barnacle died before or after the sand dollar died, and suspect it could be either. This barnacle-on-a-sand-dollar is one of those known phenomena that are pretty much not studied at all. It’s really too bad, because I’m convinced there is a fascinating story to be told.

An ocean and a lagoon

Posted on by Allison J. Gong

Yesterday and last night California was hit by an atmospheric river bringing lots of rain and the flooding that comes along with it. Combined with a spring high tide, the storm surge gave us tremendous swells and surges along the shores of Monterey Bay. At this moment it isn’t raining and the sky is lifting, so we are getting a brief break to dry out before the next storm comes through on Saturday. The National Weather Service’s small craft advisory continues through tomorrow night. The NWS forecasts continued swells of 24-26 feet, with a period of 18 seconds, for the rest of today and tonight.

I wasn’t the only person to brave the rain and see what was going on at Terrace Point. Several of the other marine lab folks were out there, and the common theme was “This is the biggest swell I’ve ever seen here!” I was grateful for my new boots and rain pants.

All of this action, combined with a high tide of +5.7 feet made for some cliff-bashing waves. When the big waves hit the cliffs, I could see large swaths of soil and ice plant falling away. Coastal erosion was happening in real time.

Here’s a 1-2 sequence of a wave smashing against the little platform where we sometimes collect water samples. I like how the gull just rises above the most violent part of the splash.

Very large wave hitting a cliff
Wave hitting platform at Terrace Point in Santa Cruz, California
2023-01-05
© Allison J. Gong

and

Very large wave hitting a cliff
Wave hitting platform at Terrace Point in Santa Cruz, California
2023-01-05
© Allison J. Gong

To get a real sense of the energy in these waves, you need video.

This is the view from Terrace Point, almost right above that little platform, then looking down the coast towards Natural Bridges State Beach.

Big swell and high tide at Terrace Point in Santa Cruz, California
2023-01-05
© Allison J. Gong

Given that I’ve been keeping a watchful eye on Younger Lagoon for the past week or so, to monitor the behavior of the sand bar, my ultimate goal for the morning was to see what was happening there behind the gate. Turns out that much had changed in the past 24 hours or so!

Yesterday, the mouth of the lagoon looked like this:

Green bushes in foreground. Sandy beach in midground, with ocean to the left. Green plants on top of dark brown cliff in background. Cloudy and dark sky above.
Mouth of Younger Lagoon, before the big swell
2023-01-04
© Allison J. Gong

This is typical Younger Lagoon after it breaches the sand bar. Water is mostly flowing out, with the occasional splash of ocean trickling in. Note how extensive the beach sand berm is.

And here it was today, taken from the same location:

Green bushes in foreground. Sandy beach in midground, with ocean to the left. The ocean is pushing from the left towards the right. Green plants on top of dark brown cliff in background. Cloudy and dark sky above.
Mouth of Younger Lagoon, after the big swell
2023-01-05
© Allison J. Gong

It wasn’t just a matter of breaching the sand bar. About half of the beach has been carved away. The ocean was pushing so far upstream that sea foam was deposited along the uppermost shores of the lagoon. All the white stuff that looks like sand? It’s sea foam.

Narrow body of water from lower left towards upper right. Green and brown foliage on both banks. Whitish foam along shores of body of water.
Top of Younger Lagoon
2023-01-05
© Allison J. Gong

But the truly impressive action was at the mouth of the lagoon. Given the rain there must have been some fresh water draining out of the lagoon, but the vast majority of the water moving back and forth was sea water. For the time being, Younger Lagoon was merely another branch of the Pacific Ocean, rather than a body of water in its own right.

Watch this video to see the effects of the combined swell and high tide on the mouth of the lagoon. The second half shows the swell pushing up into the lagoon, all the way up to and beyond the overlook.

Pacific Ocean incursion into Younger Lagoon
2023-01-05
© Allison J. Gong

I had never seen anything like this before. A week ago I was wondering how quickly the regular sand bar would re-form. Now I’m going to see how long it takes to rebuild that entire beach!

After the after the breach

Posted on by Allison J. Gong

Well, it certainly didn’t take long for the sand bar at Younger Lagoon to build up again. As described just three days ago, the lagoon burst through the sand bar and connected directly to the ocean. This was Friday 30 December 2022. Today, which is Monday 2 January 2023, I went to check on things and saw this near the overlook:

Body of water shaped like a wide letter W.
Younger Lagoon, after the rains after the breach
2023-01-02
© Allison J. Gong

That water had once again accumulated in the lagoon was evidence that the sand bar had re-formed and prevented water from draining to the sea. Well, that makes one hypothesis that I could easily test!

So I took the short hike out to the beach to see what was going on there. And what I saw was a return to normal conditions at Younger Lagoon. The sand bar had indeed re-formed and the lagoon and ocean were separate bodies of water.

Pacific Ocean and Younger Lagoon, separated by a sand bar
2023-01-02
© Allison J. Gong

We’re getting a little rain today (Monday), and should see a break between storms tomorrow. On Wednesday and Thursday we’re going to see a lot of rain, producing floods and a lot of runoff. Younger Lagoon will undoubtedly breach again before the end of the week!

After the breach

Posted on by Allison J. Gong

California is currently being slammed by another atmospheric river. A series of storms is blowing through, bringing lots of rain, which we always need. The National Weather Service has issued a flood warning and a high wind advisory here, lasting through tomorrow evening (New Year’s Eve). It is indeed blustery, and although the rainfall hasn’t been very heavy, our weather station has recorded 2 inches of rain as of 14:30 this afternoon. Slow, steady rain like this is what we need to make a dent in the state’s ongoing water deficit while (hopefully) not causing catastrophic flooding and landslides.

When we have had heavy rains for several days, I always look for Younger Lagoon to breach the sand bar and open out into the ocean. So over the past couple of weeks I went out after every rain just to see, and to watch the birds. Nada. But I always like watching birds, so it was hardly time wasted.

This morning I was at the lab doing stuff when Traci, who manages the marine mammal physiology group, found me and told me that the lagoon had breached, some time in the night. Cool! I had an appointment to get to, but had just enough time to rush down there and snap some photos. And I’m really glad I did, because I had never seen Younger Lagoon like this.

I’ve seen breaches before, but those were always fairly soon after the breakthrough, and there was a lot of water pouring out into the ocean. This morning it was very different. The lagoon had drained completely, and since there wasn’t much water running into it, the entire bottom was exposed.

This is what it looked like from near the overlook.

Green bushes in foreground. A 3-pronged body of water in the midground: one prong to the left, one to the right, and one sticking up in the middle. Top third of the image is white sky.
Younger Lagoon, empty after having breached the sand bar
2022-12-30
© Allison J. Gong

That reflective surface isn’t water. It’s the bottom of the lagoon. The bottom sediment is a shiny black, and probably smelled really bad right after the actual breach. I thought I noticed a little sulfur in the air when I came in this morning. Having seen what the top of the lagoon was like, I rushed down to the ocean end to see what was going on there.

The sand bar had been completely obliterated, leaving a sand cliff about my height. With nothing to hinder flow, was moving in both directions—every other wave or so flooding into the lagoon, and a steady light flow of fresh water draining from the lagoon.

Sand bank from upper left edge down to bottom. Ocean in the background. Water flowing between ocean on the left and right edge of photo. Cliff occupying top right corner of photo.
Younger Lagoon spilling into the ocean (and vice versa)
2022-12-30
© Allison J. Gong

Here’s a video, to give you a little taste of what it was like out there.

Younger Lagoon exchanging water with the Pacific Ocean
2022-12-30

I had never seen the bottom of the lagoon before, and wondered what it was like for the birds when the breach happened. In the past week or so I’d seen a variety of water fowl, with the occasional shorebird thrown in for extra flavor. Today there were none, even on land, where the Canada geese and mallards hang out. Granted, the wind was blowing, and birds are sensible enough to find shelter.

We’re getting more rain over the next few days, with a break in the action on Tuesday. I don’t think the sand bar will re-form for a while yet. Should be fun to keep an eye on things!

A different perspective

Posted on by Allison J. Gong

Yesterday I had the great fortune to visit a new intertidal site. It can be accessed only by crossing private property. The property owner is my next-door neighbor, and he said I can visit any time. As I said, lucky me! The site is a little north of Pigeon Point, and at first glance the terrain is not very different from Pigeon. But I could tell that it a site that is rarely, if ever, visited by humans. It just had that look of being mostly undisturbed. Yesterday’s marine layer was low, making for dark skies and pretty lousy light for picture-taking, so I had to try something new.

This site has a lot of lovely pools and channels to explore, and at this time of year the water is very clear, which does make for good picture-taking. Halosaccion glandiforme, one of the charismatic red algae, is more abundant here than at other sites, and in the pools it grows quite a bit taller than it does on the rocks.

Here’s what it looks like on the tops of the rocks. This is a cluster of young thalli. The tallest of these “bladders” is about 4 cm tall. Note that they are about 2/3 full of water, with a large air space at the top.

Many olive-green spherical and ovoid bladders, attached to rock.
Young Halosaccion glandiforme thalli along the San Mateo County coast
2022-08-14
© Allison J. Gong

The really cool thing is what happened when I stuck the camera in the water and took a shot. I got something like this:

Two elongate olive-green bladders, filled about 2/3 with water, submerged in a tidepool
Halosaccion glandiforme and other algae submerged in a tidepool
2022-08-14
© Allison J. Gong

I got a little carried away. But don’t things look interesting from the turban snail’s perspective?

Olive-green towers rising from a carpet of pink algae. A black snail is nestled between a trio of the towers.
Halosaccion glandiforme and a black turban snail (Tegula funebralis) in a tidepool
2022-08-14
© Allison J. Gong

I’m kind of enraptured by these towers of algae.

Olive-green towers rising from a carpet of pink algae.
Halosaccion glandiforme in a tidepool
2022-08-14
© Allison J. Gong

But the best part of these experiments was the reflections on the surface of the water. Check it out.

Olive-green towers rising from a carpet of pink algae.
Halosaccion glandiforme in a tidepool
2022-08-14
© Allison J. Gong

And this is the money shot! I just love how this turned out.

Olive-green towers rising from a carpet of pink algae in the bottom half of the image. The same tower are reflected in the top half of the image.
Halosaccion glandiforme in a tidepool
2022-08-14
© Allison J. Gong

This was a super fun morning. I’m looking forward to visiting this site again, when the light is better. When the daylight low tides return in a few months they will be in the afternoon. I anticipate some fantastic light shows in these pools and channels. I’ll be teaching most afternoons by then, but will get out as often as I can.