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3

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.

1

Some organisms, like some people, have a charisma that just can't be explained. For me, the sea palm (Postelsia palmiformis) has always been one such organism. Maybe part of its charm is the fact that it's not very common; it lives on rocky outcrops on exposed outer coasts, which aren't the easiest places to get to.

See? That's a clump of Postelsia way out there in the center of the photo.

Rocks covered with olive-green seaweeds in the foreground and ocean in the midground, under a cloudy sky
Algae-covered rocks in the intertidal at Pigeon Point
2022-08-13
© Allison J. Gong

The tide was pretty good (-0.9 feet) so I figured it was worth working my way out there. I had a wishlist of critters to collect, but they would be pretty easy to find, and I had time to spend in the low intertidal. The algae are still going strong, although I did see some signs of senescence in some of the reds. The Postelsia, on the other hand, were in great shape.

Group of palm tree-shaped olive-green seaweeds attached to a rock in the intertidal.
Small stand of sea palms (Postelsia palmiformis) at Pigeon Point
2022-08-13
© Allison J. Gong

Despite its beautiful olive-green colors, Postelsia is a brown alga in the phylum Ochrophyta. It is in the same order (Laminariales) as the large canopy-forming kelps Macrocystis pyrifera and Nereocystis luetkeana. However, Postelsia gets to be only about a half-meter tall. It has a thick, flexible stipe and a cluster of thin blades at the top of the stop, which give it the palm tree appearance. Postelsia's hapterous holdfast does what it says on the label—it hangs on tightly to the rock. In fact, the rock often fails before the holdfast does, and when Postelsia washes up onto the beach it often has bits of rock (or mussel or whatever) still in the grip of the holdfast.

And it turns out that Postelsia is one of the many photogenic seaweeds. This morning it was doing the '80s hair band thing. Especially when photographed from the vantage of a front-row groupie.

Postelsia palmiformis rocking the joint at Pigeon Point
2022-08-13
© Allison J. Gong

So that's the organism that captured and held my attention this morning. The algae don't get nearly the appreciation they deserve, even among fans of the rocky intertidal. Maybe shining a light on them once in a while is something I can do to fix that.

2

This summer we finally got to take a trip that had originally been scheduled for 2020. It was an Earthwatch expedition to Acadia National Park in Maine. It was also the first time I'd traveled outside the Pacific time zone, flown, and taken public transit since the COVID-19 pandemic began. All of those were stressful. I get that people are "over" the pandemic and tired of taking precautions, but seriously? During our travels before and after the expedition we saw very few other people wearing masks, despite being packed into subway cars, stations, and restaurants. We avoided indoor attractions and spent our time walking around outside.

Cloudy sky over shoreline with water and a cobble beach. Coniferous trees in the background.
Shoreline of Schoodic Peninsula in Acadia National Park, ME
2022-06-13
© Allison J. Gong

This particular Earthwatch expedition is all about climate change. During the week we participated in three different, but related, research projects in the park, mostly on the Schoodic Peninsula. The first was called Refugia. At first I couldn't tell if that was a place name, a project title, or something else. Turns out that it refers to the actual project. The target of this project is a plant called black crowberry, Empetrum nigrum. Black crowberry is a low-growing tundra plant, living near its southern limit at Acadia. This is possible because the Schoodic Peninsula juts down into the Gulf of Maine, a region where cold water from the Arctic—specifically, the Labrador Current—meets warm water from the Gulf Stream. Thus, the Schoodic Peninsula may be indeed be a climate refuge for E. nigrum.

Map showing New England coast and the Gulf of Maine. The Schoodic Peninsula is labelled.

The Gulf of Maine, however, seems to be warming more quickly than other ocean regions, possibly due to northward extensions of the Gulf Stream1. As a result, plants such as E. nigrum may be a bellwether for how the ecology of Acadia will be affected by climate change.

The Refugia study examines abundance of E. nigrum along the coast of Acadia, as well as phenology of flowering and fruiting. Our Earthwatch group sampled at Schoodic Point and Little Moose Island, which is an actual island only at high tide. We were in Acadia during the mid-June spring tide series, which is always one of the most extreme of the year, so Little Moose Island was easily accessible for several hours.

The study itself involved setting up two perpendicular transects and collecting several sets of data:

  • Geographic data—GPS location and direction
  • Photos for iNaturalist
  • Presence/absence of E. nigrum at 10 cm intervals
  • Presence/absence of flowers and fruits
  • Visual estimation of the percent of E. nigrum that is alive vs. dead

We worked in teams of four, with each pair setting up and evaluating one of the transects.

Here's how E. nigrum appears in its natural habitat:

Sloping rocks in foreground and conifers in background. In the midground, a carpet of red-and-green low-lying plants.
Coastline of Schoodic Peninsula in Acadia National Park
2022-06-16
© Allison J. Gong

The crowberry is the red-and-green plant growing low among the rocks. Like all tundra plants, E. nigrum grows low to the ground and doesn't get more than about 15 cm tall. We were told that the red bits were the parts that died back over the winter, and the green was the new spring growth.

Here's a close-up look at the carpet of crowberry:

Carpet of red-and-green low-lying plant on a rocky slope
Black crowberry (Empetrum nigrum) on the Schoodic Peninsula in Acadia National Park
2022-06-16
© Allison J. Gong

We found E. nigrum mostly in open areas, but also occasionally in the spruce forest where there is much less light at ground level. It seemed not to require much soil, and was often found tucked between rocks on the coast above the high tide line.

Black crowberry fruits are small berries, green when unripe and ripening to a blackish purple. The fruits we saw, ripe and unripe, ranged in size from 2 to 8 mm. We were told that they were unpalatable even when ripe.

Plant with short stubby leaves and cluster of small green and larger purplish berries
Cluster of black crowberry (Empetrum nigrum) ripe and unripe fruits
2022-06-13
© Allison J. Gong

The protocol had us setting up a 5-meter transect parallel to the coast, where we saw a patch of E. nigrum, and then a second 5-meter transect perpendicular to the first at its midpoint. The result is a big plus sign draped over or through whatever terrain happened to be there. We had to do quite a bit of climbing up and down rocks and pushing through bushes. If this were in California we'd have to worry about poison oak. Fortunately, they don't have poison oak in Maine, and there was no poison ivy at any of our study sites.

Four people wearing yellow high-visibility vests, standing on a rocky landscape with conifer foliage. Two long yellow measuring tapes lie on the ground and cross at their midpoints.
Transects for black crowberry (Empetrum nigrum) at Schoodic Point, by team members (left to right): Alex, Karin, Sally, and Mara
2022-06-15
© Allison J. Gong

To give you an idea of crowberry habitat, here's some wider context:

Transect pair at Schoodic Point
2022-06-15
© Allison J. Gong

The last part of the protocol was to estimate the percent of E. nigrum that was alive, in a 1-meter belt that straddles each of the transect lines. This is one of those qualitative evaluations that at first would seem to be all over the place, depending on the observer. However, the study takes into account any variation resulting from data collectors' individual estimates by pooling the percentages into bins. So instead of having to agree that 22% of the crowberry in a certain belt transect is alive, we only had to agree on a bin of, say, 20-30%. To give you an example, here's a photo of a patch of crowberry:

Black crowberry (Empetrum nigrum) at Acadia National Park
2022-06-16
© Allison J. Gong

What percentage of this crowberry is alive, in your estimation?

I should mention that we had this glorious sunny weather on only one day that we worked on the Refugia project. The first day it was raining, which was fine because we all had brought rain gear with us. But the rain made it difficult to work with the tablets on which we were recording data. The wet screens didn't want to register our finger taps, but would instead register rain drops as touches. That was incredibly frustrating. We persisted and managed.

Over the summer several other groups of Earthwatch volunteers will collect additional data for the project. I think we set a pretty high standard for the sheer number of transect pairs we completed. I liked working on this project because I got to learn about the ecology of a plant that had been entirely unknown to me. That's always fun!


1Seidov, Dan, et al. 2021. "Recent warming and decadal variability of Gulf of Maine and Slope Water." Limnology and Oceanography Vol. 66: 3472-3488.

1

Last week we had some of the best low tides of the season, and I was grateful to spend three consecutive mornings in the intertidal. The picture-taking conditions were fantastic when I went to Natural Bridges, and I snapped away like a madwoman. Unfortunately, last week was also finals week, and it wasn't until I got all of the grading done and actual grades submitted that I let myself look at the photos. And there were a lot of good ones!

There are many wonderful things about the early morning low tides. One of the best is that most people prefer to remain in bed rather than get up before the sun and splash around in cold water. The past several weeks had been very busy, with little time for solitude, and I badly needed some time by myself in nature.

Usually when I post an entry here I have a story to tell. This time I don't, unless the photos themselves tell the story. Let me know what you think.

Rocks covered in green surfgrass and brown seaweed, surrounded by water. Wave breaking in the background. Clouds in the sky.
Low intertidal at Natural Bridges
2022-05-17
© Allison J. Gong

Act I

At this time of year the algae are the stars of the show. They are at their most lush and glorious for the next several weeks.

Brown and dark iridescent seaweeds on rocks
Assemblage of mid-intertidal organisms
2022-05-17
© Allison J. Gong

Even in the sand, the algae were abundant and conspicuous. In the low intertidal the most prominent algae are the kelps. Here the feather boa kelp (Egregia menziesii) and the various Laminaria species are doing really well. Egregia also occurs higher in the intertidal, but Laminaria and Macrocystis (just visible along the right edge) are low intertidal and subtidal species.

Kelps (Egregia menziesii, Laminaria setchellii, and Macrocystis pyrifera) in the low intertidal
2022-05-17
© Allison J. Gong

My absolute favorite sighting of the morning was this group of algae on top of the sand. I love the way that the algae are splayed out. They are just so pretty!

Assemblage of algae in the sand
2022-05-17
© Allison J. Gong

Macrocystis pyrifera is justifiably well known as the major canopy-forming kelp along our coast. But it does occur in the low intertidal, as mentioned above.

Long strands of golden-brown seaweed
Giant kelp (Macrocystis pyrifera)
2022-05-17
© Allison J. Gong

Intermission

Act II

And now to focus on some individual organisms. Starting with my favorites, the anemones. This time it was the giant green anemone, Anthopleura xanthogrammica, that was the star of the show.

Large bright green sea anemone
Green anemone (Anthopleura xanthogrammica)
2022-05-17
© Allison J. Gong

I experimented with close-up shots, too!

There was a clingfish (Gobiesox meandricus), in its usual under-rock habitat. Don't worry, I made sure to carefully replace the rock as I found it. This fish was about 10cm long. It may be the first clingfish I've ever seen at Natural Bridges. Clearly, I need to do more rock flipping.

Mottled brown fish with large head, on a rock
Northern clingfish (Gobiesox meandricus)
2022-05-17
© Allison J. Gong

A clingfish's pelvic fins are fused together and modified to form a suction cup on the ventral surface. Clingfish can hop around a bit and are super cute when they eat. They sort of dart forward and land on the food, then shuffle around as they ingest it.

The coralline algae were both abundant and flourishing. They are looking fantastic this season. Someday I'll study up on the coralline algae and write about them. For now, here are some happy snaps of Bossiella.

Pink, stiff, seaweed. Body of repeated sections.
Bossiella sp., one of the erect coralline algae
2022-05-17
© Allison J. Gong

Such a beautiful organism!

Sticking with the pink theme, another oft-overlooked organism is the barnacle Tetraclita rubescens. It has a few common names, including pink volcano barnacle and thatched barnacle. It is the largest of the intertidal barnacles along the California coast, and can be fairly abundant in some places. It is never as abundant as the smaller white (Balanus glandula) and gray/brown (Chthamalus dalli/fissus) barnacles, though.

Large pink barnacles on a rock
Tetraclita rubescens, the large pink barnacle
2022-05-17
© Allison J. Gong

Which brings us to my favorite color, purple. The tentacles of the sandcastle worm, Phragmatopoma californica, are a beautiful shade of purple. You don't get to see the tentacles unless the worm is under water, and with the tide as low as it was when I was there this past week, it wasn't easy finding any Phragmatopoma that were submerged. I've written about Phragmatopoma before, so won't go into details here. But look at all those fecal pellets!

Tentacles of the sandcastle worm, Phragmatopoma californica
2022-05-17
© Allison J. Gong

And last but not least, here are a couple of the many purple urchins (Strongylocentrotus purpuratus) out there. At Natural Bridges there's a large pool fairly high in the mid-intertidal that is called the Urchin Pool because it contains dozens (hundreds?) of urchins. Most of them are burrowed into the soft rock. Those are sort of easy pickings. I like finding urchins in less-obvious places, like these.

Purple urchins (Strongylocentrotus purpuratus) tucked into burrows
2022-05-17
© Allison J. Gong

Urchins in the intertidal often cover themselves with bits of shell, small pebbles, and algae. This helps them retain water as the tide recedes. At a location where the rock is soft, such as Natural Bridges, many of the urchins have grown larger than the opening to their burrow and cannot leave to forage; these imprisoned urchins have to wait for pieces of algae to drift nearby, which they can grab with their tube feet and then transport to the mouth on the underside. So long as they don't get pried out by otters, the urchins seem to do just fine.

I think that's enough for now. I hope these photos give you some idea of what it was like out there a week and a half ago. The next excellent low tide series is in mid-June. Snapshot Cal Coast will be in full swing then, so get out there if you can!

Row of people with backs to the camera, standing on a bluff and looking out over the ocean

For the final field trip of the quarter for Introduction to Field Research and Conservation, I took the class to the Landels-Hill Big Creek Reserve. Located in the Santa Lucia Mountains south of Big Sur, Big Creek was the fourth of the UCSC Natural Reserves we visited this quarter. The site is rugged and spectacular, and because it's not open to the public we were the only visitors there. There's something truly special about arriving at a campsite after dark (which most of us did) and waking up to find that you've landed in paradise. And realizing that you haven't pitched your tent in poison oak!

Saturday 07 May 2022

We had about a day and a half at Big Creek. Saturday we went on a hike that was much longer and more grueling than the gentle saunter I had promised the students. If I get to teach this class again and return to Big Creek, I now have better plans for how to manage things. We did hike through areas that burned in the Dolan fire in 2020, and were able to see first-hand now the landscape is recovering from that disturbance.

Landscape photo of mountains in background, burned trees in midground, and green vegetation in foreground.
Scorched trees
2022-05-07
© Allison J. Gong

First, some facts about the Dolan Fire. It was started in the Los Padres National Forest in August 2020 by a man who was convicted of arson, throwing rocks at a vehicle, cultivating marijuana on public lands, and 12 counts of animal cruelty; this man, whose name shall go unmentioned here, was sentenced to 24 years in prison just a few days ago. The fire burned over 124,000 acres, cost the state $63 million to fight, destroyed 10 residences and four other structures, and damaged nesting sites for California condors, resulting in the deaths of 12 of the endangered birds. One of the casualties of the fire was the outhouse at the Redwood Camp campground, which is where we were camping. The outhouse had been rebuilt recently and was brand spanking new when we arrived.

Outhouse at Redwood Camp
2022-05-07
© Allison J. Gong

Yes, it's a lovely outhouse, but I really took this photo to show the burnt trees. Redwood Camp is situated alongside Devils Creek, in the redwood forest. The fire came right down to the road and scorched trees along the canyon wall. Many dead trees had to be removed and trails cleared before Big Creek could reopen.

Our hike-that-was-more-than-a-saunter took us up the fire road to Whale Point, where we had spectacular views of the Santa Lucia Mountains in one direction and the Pacific Ocean in the other. Along the fire road our guide showed us fire damage to the redwood forest, and pointed out signs of recovery.

Redwoods are adapted for fire. They have a thick bark that shields the inner living tissue from damage, so long as the fire isn't too hot. The outermost layer of bark is frizzy and burns really fast, so a redwood on fire blazes like a match catching for a few seconds, then goes out. Old redwoods have few, if any, branches near the ground, so a low temperature fire at ground level would cause very little damage to a healthy tree. Fire clears out the underbrush and opens up the canopy, creating an opportunity for some young sapling to reach for the light. Fire suppression, on the other hand, allowed the accumulation of several decades' worth of vegetation, and when the Dolan Fire came through it burned hot and furious.

I knew, of course, that redwood trees are clonal. They sprout new trees from the roots and can eventually form "fairy rings". These occur when a mother tree puts up a ring of clonal offspring. Eventually the mother dies, leaving a ring of trees surrounding either a stump or an open space. We see in the Santa Cruz redwoods all the time.

What I didn't know, but learned at Big Creek, was that redwoods also have epicormic growth, in which new shoots originate from the beneath the bark of the tree, sometimes halfway up the trunk.

Scorched tree trunks with new sprouts growing high above the ground
Redwood trees (Sequoia sempervirens) showing epicormic growth
2022-05-07
© Allison J. Gong

Epicormic buds lie dormant underneath the bark layer, their growth suppressed by hormones released by active shoots higher up in the tree. When those higher shoots are damaged, the cessation of hormones allows the epicormic buds to begin growing. The selective advantage of sprouting new growth halfway up the tree is that the new shoots have less far to grow to reach the sun. With redwoods being so tall, an epicormic bud located halfway up the trunk has a major leg up on the competition trying to grow from ground level.

However, that doesn't mean that many trees damaged by fire don't grow from roots. We saw lots of those, too. Our guide said that post-Dolan some redwoods grew from root sprouts and some from epicormic buds, and that there wasn't really any rhyme or reason as to which trees did which.

Young redwood sprouts, with new growth in bright green
Young redwood (Sequoia sempervirens) sprouts, age 1 year
2022-05-07
© Allison J. Gong

These young trees sprouted in 2021, a few months after the Dolan Fire was extinguished on 31 December 2020. The first year's growth is the dark green color. The new growth added in 2022 is the brighter and paler green. Here's another young tree where the color between the 2021 and 2022 growth is more striking:

Young redwood sprouts, with new growth in bright green
Young redwood (Sequoia sempervirens) sprouts, age 1 year
2022-05-07
© Allison J. Gong

The reward for the hike was a long rest at Whale Point, which we started calling The Top of the World. Because with views like this, who can argue?

25 people standing on a bluff above the ocean
Students listening to our guide at Whale Point
2022-05-07
© Allison J. Gong

Sunday 08 May 2022

After breakfast on Sunday the students packed lunches and dispersed to work on their rapid research projects (RRPs). The RRP is a field exercise in which students devise an entire research project, from initial observations and questions to final presentation, in a few hours. I've found it to be a very effective assignment, because it forces students to simplify and narrow their ideas. They simply can't get too carried away if they have to make a poster and present it to their classmates in half a day. When students are working on RRPs my job is to keep them focused and on-task. Sometimes this is easier said than done. We had students working in the forest, in the creek, and on the beach.

At Big Creek there's a new classroom built down by the beach. No matter where the students did their actual research, we would all meet at the classroom to build and present posters.

Modern building in outdoor setting
Classroom building at Big Creek Natural Reserve
2022-05-08
© Allison J. Gong

It's hard to see in the photo, but to the right of the middle of the building, in the corner of the ell, there's a glass door. Directly across on the opposite side of the building there's another glass door, so you can see all the way through the building. We discovered that this is a problem, as two birds had tried to pass through the building and smacked into the glass. They were both dead. So on the spur of the moment I turned it into an impromptu lesson.

I couldn't ID either bird off the top of my head, so a handful of students and I sat down with the birds and some field guides to study bird anatomy and identification.

6 women sitting cross-legged on a wooden deck, one with an open book on a knee. Two dead birds in the middle of the circle.
Me, trying to ID the dead birds
2022-05-08
© Allison J. Gong

We talked about different types of feathers—primary and secondary flight feathers, coverts, tails—and their functions. After working through descriptions in the field guides I was pretty certain that the larger bird was a Swainson's thrush (Catharus ustulatus) and the little yellow bird was some sort of warbler. It was a good lesson for the students, because we looked at physical descriptions and geographic ranges, and could not come up with a definitive answer. I took several pictures of both and uploaded them to iNaturalist when we got home. We were correct about the brown bird, and the little yellow one ended up being an orange-crowned warbler (Leiothlypis celata).

Two dead birds lying on wooden deck. Bird on top is small and yellow, bird on bottom is larger and brown.
Orange-crowned warbler (Leiothlypis celata, top) and Swainson's thrush (Catharus ustulatus, bottom)
2022-05-08
© Allison J. Gong

The RRPs were the last part of the field trip, and after that we packed up and headed out. The students went straight back up the coast to get home, and saw three California condors from the highway. Alex and I drove back up to Whale Point where it was really windy, just to see condors, and didn't see any. Go figure. At least I had my camera with me and could take real pictures. And it was another beautiful day.

Big Creek Bridge, one of the iconic bridges along Highway 1
2022-05-08
© Allison J. Gong

I am one fortunate woman, because I get to call this work!

1

Big waves breaking on beach, with cliffs on the right side

One of the things that I've been doing with my Ecology class since almost the very beginning is LiMPETS monitoring in the rocky intertidal. Usually we have a classroom training session before meeting in the field to do the actual work. This year we are teaching the class in a hybrid mode, with lecture material being delivered remotely, so we don't have class meetings except for our field trips. The LiMPETS coordinator for the Monterey Bay region, Hannah, and I arranged to meet at our sampling site, where she would do a training session on the beach before we herded everyone out into the intertidal. It truly was a great plan! But the weather intervened and a spring storm blew through, bringing in a big swell. There was a high surf warning for our area the day of our scheduled LiMPETS work. Hannah and I conferred via email and decided that we'd still give it a shot, and at least the students would have an opportunity to learn about the LiMPETS program and practice with the datasheets and gear.

I arrived early to see how the surf was looking, and it was impressive. The waves were regularly covering our sampling location with whitewash, even as the tide was going out. When my co-instructor arrived and I showed him where the transect would lie, it was an easy decision to make to cancel the monitoring. But we would still be able to do the practice stuff, so we convened with Hannah on the bluff and she went into teacher mode.

College students standing in a circle, listening to instructor
Hannah (right) explaining the LiMPETS program
2022-04-22
© Allison J. Gong

We didn't bother with the transect, but had groups of students work through some quadrats out on the intertidal bench, which you can just see in the background of the photo above. Hannah kept everyone out of the danger zone and we stressed the importance of having one member of each group keep an eye on the ocean at all times. We stayed mostly in the high zone, venturing down into the upper mid zone only when the tide was at its lowest. Even then, the big swells would surge up the channels and splash up onto the benches. Nobody got swept off, though, or even more than a teensy bit damp.

Most of the students left after what little work we had for them to do, and that gave me the freedom to poke around on my own and take pictures. I hadn't had a chance to do this in a long time, and intended to make the most of a decent low tide that was almost wiped out by huge swell.

So here we go!

First up, the high-intertidal seaweeds:

Olive-green seaweed on rock, with mussels surrounding
Silvetia compressa
2022-04-22
© Allison J. Gong

And here's a typical high intertidal community at Davenport Landing. Inhabitants include:

  • Several large clumps of rockweed (Silvetia compressa and Fucus distichus)
  • Several smaller bunches of tufty reds (Endocladia muricata)
  • Mussels (Mytilus californianus)
  • Many blotches of "tar spot alga" which is the encrusting tetrasporophyte phase of Mastocarpus papillatus
Clumps of olive-green seaweeds, dark red seaweeds, and mussels on rock
High intertidal community at Davenport Landing
2022-04-22
© Allison J. Gong

The water was pretty murky, so not great for underwater photography. Some of the shots turned out pretty well, though. The soft pale purple structures that you see in the photo below are papullae, used for gas exchange. You can see these only when the star is immersed.

Clumps of pale purple transparent tubes interspersed with white blotches
Aboral surface of the ochre star Pisaster ochraceus, showing papullae and spines
2022-04-22
© Allison J. Gong

The anemones were, as always, happy to be photographed. In this shot, the anemone was being photobombed by a turban snail.

Large green sea anemone and small purple snail in a tidepool
Green anemone (Anthopleura xanthogrammica) and black turban snail (Tegula funebralis)
2022-04-22
© Allison J. Gong

Here's another typical intertidal assemblage:

Clump of sandy tubes with mussels, barnacles, and greenish-purple seaweed
Sandcastle worm (Phragmatopoma californica), iridescent alga (Mazzaella flaccida), gooseneck barnacles (Pollicipes polymerus), and mussels (Mytilus californianus)
2022-04-22
© Allison J. Gong
Gooseneck barnacles (Pollicipes polymerus)
2022-04-22
© Allison J. Gong

A couple of students stayed after the rest of the class had left. They were happy to see the nice fat ochre stars, and so many of them in one small area.

It's always good to see so many big ochre stars. For this species, in the intertidal areas that I visit, sea star wasting syndrome (SSWS) no longer seems to be a problem. Fingers crossed! We'll have to see what unfolds in the next months and years.

1

This weekend, 18-21 February 2022, are the four days of the Great Background Bird Count. This is a global community science project in which people go out and document bird life. The beauty of a project like this is that is available to anyone who has a window to the outside. Of course, anybody can look at birds any time. To participate in the official project, people need to add their observations to eBird, which is similar to iNaturalist only specific to birds.

Day 1

Date/time: Friday 2022-02-18, 09:00-10:00
Location: Younger Lagoon overlook
Weather: Sunny, with very slight overcast; no breeze at first, but light breeze after about 09:30

  • Canada goose (Branta canadensis): 6
  • Mallard (Anas platyrhynchos): 4 female, 4 male
  • Bufflehead (Bucephala albeola): 4 female
  • American wigeon (Mareca americana): 4 female, 5 male
  • American coot (Fulica americana): 12
  • Northern harrier (Circus hudsonius): 1
  • Red-tailed hawk (Buteo jamaicensis): 1
  • Red-winged blackbird (Agelaius phoeniceus): hard to say, but at least 20 lekking away in the field across the lagoon
  • Osprey (Pandion haliaetus), carrying a fish!: 1
  • European starling (Sturnus vulgaris): murmuration of ~100
  • Bewick's wren (Thryomanes bewickii): 1
  • Song sparrow (Melospiza melodia): 2
  • Yellow-rumped warbler (Setophaga coronata): 2 male
  • Anna's hummingbird (Calypte anna): 2 male
  • Bushtit (Psaltriparus minimus): ~15
  • American crow (Corvus brachyrhynchos): 2
  • California quail (Callipepla californica): 1 male
  • California thrasher (Toxostoma redivivum): 1
  • Golden-crowned sparrow (Zonotrichia atricapilla): 1
  • Black phoebe (Sayornis nigricans): 1
  • Spotted towhee (Pipilo maculatus): 1
  • Common yelllowthroat (Geothlypis trichas): 1 male

In addition to this tally of species, which is fine in and of itself but not all that interesting, I did get to see some interactions. The northern harrier is a perennial resident, and I often see it either perched on a fence post across the lagoon or soaring low over the fields. Today the red-tailed hawk was perched on a fence post, and I didn't see the harrier until it flew in several minutes later. The harrier crossed in front of the hawk, flying low, and flushed out a murmuration of starlings. It chased the starlings around for a little while, obviously not hunting them. And as much as I wish starlings hadn't been introduced to North America, the flow of a murmuration is fascinating to watch. Even a small one of about 100 birds is rather impressive. Anyway, the hawk on the fence post watched all this activity for a few minutes and seemed to be rather peeved by all the kerfuffle. It ruffled its feathers and flew off. The harrier flew away later, and the starlings kept up their murmuration until I left.

On this winter solstice, as we anticipate the return of light, I thought I'd write about a different kind of light.

Merriam-Webster defines fluorescence as "luminescence that is caused by the absorption of radiation at one wavelength followed by nearly immediate reradiation usually at a different wavelength and that ceases almost at once when the incident radiation stops". It is a type of luminescence that occurs in both biological and non-biological objects. For example, mushrooms and scorpions are notably fluorescent, as are several minerals. Technically, to qualify as "fluorescent" an object can absorb any wavelength of radiation and re-radiate any other, although the re-radiated wavelength is usually longer than the absorbed wavelength.

We humans, with our three (and occasionally four) color photoreceptor types, can see only the tiny fraction of the electromagnetic spectrum that we call visible light. The visible light range (approximately 400-700nm) is bounded by UV on the short end and infrared on the long end. Other organisms have very different light perception capabilities. We know, for example, that insects can see in UV and pit vipers can see in infrared. And as for mantis shrimps, which have as many as 12 types of photoreceptors, we don't yet understand how they see the world, but you can bet it's nothing like the way we do. For practical purposes, fluorescence is most easily seen when an object absorbs UV light and re-radiates light of a longer wavelength that falls into the visible light range.

When you shine a UV light on one of these fluorescent objects, you see an apparent color change from whatever it looked like under visible light. This color change is most striking in the dark, because the fluorescent object will appear to glow. The same thing happens in daylight, but is obviously more difficult to see.

Here, let me show you. A few weeks ago I went to Natural Bridges to photograph the anemones, first under normal daylight conditions and then under UV light. I have a pretty wimpy UV flashlight, it turns out, but you can still see the fluorescence.

Here's Anemone #1, under daylight:

Sea anemone in daylight
Sunburst anemone #1 (Anthopleura sola) at Natural Bridges
2021-12-07
© Allison J. Gong

And here's Anemone #1 under UV light:

Sea anemone under UV light
Sunburst anemone #1 (Anthopleura sola) at Natural Bridges, under weak UV light
2021-12-07
© Allison J. Gong

Striking difference, isn't it?

This is Anemone #2. It was getting dark by then, but this photo was also taken without flash and I did not increase exposure of the image.

Sea anemone
Sunburst anemone #2 (Anthopleura sola) at Natural Bridges
2021-12-07
© Allison J. Gong

And, under UV light:

Sea anemone under UV light
Sunburst anemone #2 (Anthopleura sola) at Natural Bridges, under weak UV light
2021-12-07
© Allison J. Gong

Here's what's going on. Pigment molecules in the anemones' tissues are absorbing the UV radiation and re-radiating light in the visible range. It's easier to see the fluorescence in Anemone #2 because it was much darker when I took that set of photos. Fluorescence still occurs during the day, but we can't see it as well in the daylight. This is why our local bowling alley does their Atomic Bowling at night! They can dim the overhead lights, crank up the black lights, and let the tunes roll.

Incidentally, if you've ever wondered why so-called black lights are purple, there's a reason for it. A true black light emits only UV light. UV light is invisible to us, hence the term "black", as in pure darkness. UV lights that ordinary folks like us can buy are tinged purple so that we can see it. The purple isn't UV, of course, but seeing the purple light keeps people from looking into the beam and frying their retinas from the actual UV radiation.

Sea anemones, of course, do not celebrate the solstice, but they do perceive it. They, and just about every other living thing, can sense the cyclical changes in day length as the year progresses. After tonight the days will start getting longer as we move through winter and towards spring. Personally, I cannot wait until we get the early morning low tides in the spring.

In the meantime, happy solstice, everyone!

Yesterday I had some time to kill before getting a COVID test, and, as usual, wandered down to the ocean. This time I was at Seacliff State Beach. It was pretty crowded, so I walked onto the pier to see if the fishermen were having any luck. They weren't, really. One man kept catching jack silversides (Atherinopsis californiensis) that were too small to keep. There was a lot of banter about sharks and bait and crabs, but what I witnessed yesterday confirms my hypothesis that a lot of what people call "fishing" is merely an excuse to get outside for a few hours. And there is absolutely nothing wrong with that.

As for me, I have nowhere near enough patience to make a decent fisherman. I did, however keep myself amused by eavesdropping on their conversations and writing snippets in my nature journal. I did also find myself mesmerized by the anchovies. Watch for yourself.

Northern anchovies (Engraulis mordax) at Seacliff State Beach
2021-11-23
© Allison J. Gong

Like sardines, anchovies are planktivorous filter feeders. If you watch the video again and can focus on an individual fish for a while, you'll see that as it swims forward, the front end becomes white and bulbous for a few seconds. That's sunlight reflecting off the fish's jaws. Anchovies have metallic silver coloring, which is a defense against predators. For fish that live in surface waters that are brightly lit, all of those glinting flashes of light make it difficult for a predator to zero in on a single fish to pursue. There is safety in numbers, and for anchovies the silvery coloring combined with schooling behavior means that if a predator manages to catch some of the fish in the baitball, most will avoid being eaten. This works against predators such as larger fish, squid, and birds, which generally capture one or a few fish at a time. But if the predator happens to be a humpback whale, which is capable of engulfing the entire school, then the anchovies are SOL. Think about it, though. For any anchovy, the probability of encountering a larger fish, squid, or bird is much higher than encountering a humpback or blue whale. Thus the selective advantage of schooling!

Okay, now back to the feeding. Anchovies have really long jaws for their size and can, like snakes, open their mouths very wide. This allows them to filter as much water as possible as they swim. Food, mostly plankton, is caught on the gill rakers, which are bony or cartilaginous structures projecting forward (i.e., towards the mouth) from the gill arches. Some fishes' gill rakers are nothing more than short nubs. Filter feeding fishes such as anchovies have long thin gill rakers. Water enters the mouth as the fish swims forward, and plankton is caught on the array of gill rakers. The water then passes over the gill filaments, where respiratory exchange occurs, and then out from underneath the operculum. Anchovies cannot suck water into their mouths, and thus can feed only while swimming forward, or ramming water into the mouth. This is a type of feeding called ram feeding.

These anchovies were very close to shore. They were feeding, so obviously there was plankton in the water. I haven't done a plankton tow in a while, as I generally assume that fall/winter plankton isn't as interesting as spring/summer plankton. However, given the presence of feeding anchovies inshore, it might be time to test that assumption.

I go to Natural Bridges quite often, to play in and study the rocky intertidal. But at this time of year, before the low tides really get useful, there is another reason to visit Natural Bridges—to see the monarch butterflies (Danaus plexippus). Natural Bridges State Park is a butterfly sanctuary, providing a safe overwintering spot for migrating monarchs.

Yesterday morning, while it was still cool enough for the butterflies to be hanging in clusters, I went out and photographed them. Last year's count was only 550 for the winter, but I'd heard that there were more butterflies this year and it was definitely worthwhile going out and looking for them.

Monarch butterflies clustered in eucalyptus tree
Monarch butterflies (Danaus plexippus) at Natural Bridges State Park
2021-11-06
© Allison J. Gong

The butterflies rest with their wings up, so when they are hanging like this you see the duller underside of the wings. A few of them were starting to warm up their flight muscles and showing off the more brilliant orange of the dorsal wing surface.

Monarch butterflies clustered in eucalyptus tree
Monarch butterflies (Danaus plexippus) at Natural Bridges State Park
2021-11-06
© Allison J. Gong
Monarch butterflies clustered in eucalyptus tree
Monarch butterflies (Danaus plexippus) at Natural Bridges State Park
2021-11-06
© Allison J. Gong

I am really not good at counting things like this, but my guess is that there were hundreds of butterflies, all told. Based on the 2020 season, when I didn't see any monarchs at all at my house and only a few scattered individuals at Natural Bridges, this year's population seems to be doing much better. 2020 was an awful year in California in general, and in the Santa Cruz region in particular. The CZU August Lightning Complex fire put air quality into the unhealthy-for-everybody range for several weeks. Much of the rest of the western U.S. also burned, with much habitat loss for nature. Maybe that's part of why there were so few monarchs last winter in Santa Cruz. Of course, the monarchs' populations have been declining for years, so last year's population crash may be only a dip in the grand scheme of things.

Whatever the cause, it really was good to see even this many butterflies at Natural Bridges.

Oh, and before starting my butterfly hunt in earnest, I spent about an hour watching and listening for birds. I wanted to get the birdwatching in before human activity drowned out the birdsong. Unfortunately, most of what there was to hear was the cawing of crows.

Nature journal page of birds seen and heard
Page from my nature journal

Next time I'm at Natural Bridges, I'll try to remember to check in with the visitor center to see what the official count for monarchs is. Fingers crossed the number is a lot higher than 550!

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