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.
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.
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.
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.
Dedication: For Krinkle, because I think he’d appreciate the juxtaposition
This is one of my favorite quotations from literature:
And it is a strange thing that most of the feeling we call religious, most of the mystical outcrying which is one of the most prized and used and desired reactions of our species, is really the understanding and the attempt to say that man is related to the whole thing, related inextricably to all reality, known and unknowable. This is a simple thing to say, but the profound feeling of it made a Jesus, a St. Augustine, a St. Francis, a Roger Bacon, a Charles Darwin, and an Einstein. Each of them in his own tempo and with his own voice discovered and reaffirmed with astonishment the knowledge that all things are one thing and that one thing is all things—plankton, a shimmering phosphorescence on the sea and the spinning planets and an expanding universe, all bound together by the elastic string of time. It is advisable to look from the tide pool to the stars and back to the tide pool again.
—J. Steinbeck and E.F. Ricketts, Log from the Sea of Cortez
These words are never far from my thoughts when I contemplate the nature of life on planet Earth. And with this week’s release of the first images from the James Webb telescope, they rocketed back into my brain with full force.
To my eye, the most striking of these first images from James Webb is this one, of the Carina Nebula. It is just breathtaking.
Carina Nebula, photographed by the James Webb space telescope 2022-07-12 Public domain by NASA
When I started poking around NASA’s website I kept finding images that reminded me of my tide pool photos. So I want to share a few comparisons.
Stephan’s Quintet
NASA also released this photo of Stephan’s Quintet, a group of five galaxies found in the constellation Pegasus. Only four of the five galaxies are visible in this image.
Stephan’s Quintet, photographed by the James Webb Space Telescope 2022-07-12 Public domain by NASA
Those swirling white masses are vast sweeps of dust and gas. But to my mind they resemble spawning male marine invertebrates, of which I have seen more than any normal person. See what I mean?
Given all the justified hype over the images taken by James Webb, it’s sort of easy to forget about the Hubble Space Telescope. But Hubble has been taking spectacular images for years, giving humanity some of our first and best images of the universe far from home.
Abell 370
In the archived data from the Hubble Space Telescope, I found several eye-catching photos. This one, of Abell 370, reminded me of plankton. Abell 370 is another cluster of galaxies. It contains hundreds of galaxies held in a group by their mutual gravitational pulls. I love all the shapes of these galaxies, which do indeed look like plankters!
Abell 370, photographed by the Hubble Space Telescope in 2017 Public domain by NASA
In 2021 the Hubble Space Telescope took a photograph of the Prawn Nebula. As with most of images of amorphous things in space, I can’t explain why the Prawn Nebula has that name. Most of the light it emits is in wavelengths that we cannot see, so the Prawn Nebula is essentially invisible to the naked eye. This image from Hubble was taken in infrared light, and is beautifully colorful.
The Prawn Nebula, photographed by the Hubble Space Telescope in 2021 Public domain by NASA
The colors in this nursery for baby stars reminds me of the ones I see in some of our iridescent algae in the intertidal here on Earth.
In 2016, NASA’s Juno mission arrived at its target, the largest planet in our solar system. The vehicle carries a camera called the JunoCam, which sends data back to Earth. NASA collects the raw images and makes them available to the public for free, to be processed and edited. The public is thus making an ongoing contribution to science. The JunoCam is still operational. NASA also invites amateur astronomers to add their own photos of Jupiter, taken from personal telescopes, to the database of images.
Anyway, here’s a photo of Jupiter, taken by JunoCam and processed by Brian Swift:
Credit: NASA/JPL-Caltech/SwRI/MSSS/BrianSwift
All of these lovely swirls brought to mind the patterns I sometimes see on the surface of a tide pool.
And now, having spent several hours marveling at the beauty of the stars as captured by the Hubble and James Webb telescopes, I take Steinbeck’s and Ricketts’ advice and return to my tide pool image library, where I see other swirling patterns that I did not find in any of the space photos. But I hope that they will be found out there, some day.
By all means, look up at the stars and marvel at the vastness of the universe. But don’t forget to also look down at where your feet are and marvel at the intricacy and exquisite beauty of what we can experience with our human senses.
On our last afternoon at the Schoodic Institute we were dealing with laundry for our upcoming several days touring in New England. On the way back from the laundry room we came across this little creature waddling towards us. It was a porcupine! It kept coming towards us, even as we were backing away. Clearly it had some place to be.
Porcupine (Erethizon dorsatus) at the Schoodic Institute in Acadia National Park 2022-06-17 @ Allison J. Gong
I don’t know whether or not porcupines are always this nonchalant around humans. This one crossed the road in front of us and headed off into the woods. And look, it’s plantigrade!
And then it nibbled on a few leaves and climbed a tree! Note how it uses the tail as a brace, the way woodpeckers do when they’re hopping up and down trees.
We had to meet up with the rest of the Earthwatchers for a celebration event in the classroom and didn’t get to keep watching this porcupine. However, on our way to the dining hall for dinner, we saw the same animal, on the ground again. And this time she was accompanied by a baby! It was getting dark by then and I didn’t want to bother either mama or baby, so didn’t take any additional photos or video.
We never did see any moose in New England, despite all the road signs promising “Moose X-ing next <insert positive integer> miles”, but seeing a porcupine was pretty dang cool. What a terrific send-off from the Schoodic Institute wildlife!
One of the reasons I selected this particular Earthwatch expedition was that it involved studies of both forest and ocean, which are my two favorite ecosystems here at home. I wanted to compare what I’m familiar with to similar habitats on the opposite coast. Regarding the rocky intertidal, I had been warned not to expect the spectacular biodiversity I’m used to on the Pacific coast, and that warning turned out to be quite a propos.
Along the California coast the rocky intertidal is an explosion of colors and textures, especially during the growing season. See this at Pigeon Point:
And this is what you see when you walk—or in the case at Pigeon Point, climb down—to the site. It just is this varied, with several algae that are easily recognizable as being different even if you don’t know what their scientific names are.
Contrast that with the rocky intertidal at Frazer Point on the Schoodic Peninsula:
All of the algae covering these rocks are rockweeds, and most of it is Ascophyllum nodosum. One of the projects we worked on was a study measuring the biomass of Ascophyllum on the coast of the Schoodic Peninsula. To do so we sampled along 30-meter transects in the intertidal, counting the number of Ascophyllum thalli in half-meter quadrats, looking for other algae and some key invertebrates, and weighing the Ascophyllum. This last part was new to me, and a lot of fun. It involved dividing the masses of Ascophyllum into as many as three bundles, wrapping it all up in a net like a burrito, and weighing the burrito using a hand-held metric scale.
Clearly, Ascophyllum nodosum makes up the vast majority of biomass along this coastline. There are some other rockweeds in the genus Fucus, a bit of sea lettuce (Ulva sp.), and that’s about it. But the lack of diversity doesn’t mean the intertidal doesn’t have its own sort of spartan beauty. The lead for this project, Maya, described Ascophyllum as having a Van Gogh effect in the landscape. It didn’t take long to see what she meant. Check it out:
There are, of course, many types of beauty in the natural world. What I saw in the intertidal at Acadia wasn’t at all like what I’m used to seeing on the Pacific coast, but I wouldn’t say it is any less beautiful. The variation in color between new growth and the older parts of the Ascophyllum thalli makes for gorgeous patterns as the thalli drape over cobbles.
Besides, any morning in the intertidal is a good morning! I certainly wasn’t going to complain.
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.
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.
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:
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:
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.
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.
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:
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.
One of the many delightful animals in the rocky intertidal is the vermetid snail, Thylacodes squamigerus. Unlike their more typical gastropod relations, the vermetids don’t live in a shell, per se. Instead, they live in a calcareous tube, which forms a loose coil draped over the surface of a rock. The tubes can be up to about 12 mm in diameter, and, if straightened out, about 15 cm long. In some locations, Thylacodes can be very abundant. In a recent visit to Point Pinos in Pacific Grove, I saw many of them in the low intertidal. I occasionally see them on the northern end of Monterey Bay and points farther north, but at nowhere near the abundance I see in Pacific Grove. At a larger scale, iNaturalist shows observations of T. squamigerus from northern British Columbia down to southern Mexico.
Most snails are either grazers (e.g., abalones, limpets, turban snails) or predators (e.g., whelks, conchs, cone snails). Thylacodes is a bit of an outlier with regards to feeding as well as housing, for it is a suspension feeder. Being entirely sessile, it cannot go out and forage. And unlike its doppelganger, the tubeworms Serpula columbiana and S. vermicularis, Thylacodes does not create a water current to catch food on ciliated tentacles. Instead, it spins threads of sticky mucus that thrash around in the current and capture suspended detritus. When the tide is out the snail hunkers down in its tube, same as any worm. It cannot feed unless it is immersed. Where the worms live in the low intertidal on exposed rocky coasts, the water is moving constantly, and it requires relatively little energy for Thylacodes to feed the way it does. As a bonus, even the calories expended in producing the mucus are recouped, as the snail ingests the mucus strands as well as the food particles they capture.
When the tide came back, I got to watch Thylacodes in action. At Point Pinos there are some areas that form lovely tidepools, deep enough for animals to react to the return of the water and clear enough to make photography and videography possible. So standing knee-deep in a pool I stuck the camera underwater and hoped for the best. And I got lucky—you can see the mucus threads!
And not only that, but I captured some video footage. I use a point-and-shoot for these underwater shots, and usually don’t know what or whether I’ve shot anything good until I download images and video at home. Color me happy to have seen these clips!
Despite the unusual aspects of its biology, Thylacodes is indeed a snail. It has a conventional snail’s radula, and uses it the way, say, an owl limpet (Lottia gigantea) uses hers to scrape algae off rocks at Natural Bridges. Only instead of scraping the radula against rocks, Thylacodes uses its radula to reel in the detritus-laden mucus threads. That’s what’s going on in the second video clip above.
So there you have it, another of my favorite animals. Thylacodes is one of those animals that doesn’t look like much when you see it just sitting there. But we get to see it only during the tiny fraction of its life that it spends emersed. As with most inhabitants of the rocky intertidal, much of Thylacodes‘ life occurs out of sight for human eyes. This makes the occasional sighting of Thylacodes under water especially enlightening. And delightful!
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.
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.
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!
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.
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.
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.
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.
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.
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!
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.
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!
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.
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.
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.
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.
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:
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.
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.
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).
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.
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.
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.
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.
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.
This week was my spring break, and although I have more than enough work to catch up on, I decided that each day I would spend a few hours doing something fun before or after getting stuck in with adult responsibilities. I didn’t set up formal plans, but knew I wanted to collect a plankton sample early in the week. Monday 21 March 2022 was the vernal equinox, which seemed as good a time as any to see what was going on in the plankton.
And the plankton was quite lively! I was very pleased to see a lot of diatoms in the sample. Diatoms are early season bloomers, able to take advantage of nutrient inputs due to coastal upwelling. They are usually the most abundant phytoplankters from about March through July.
All of those button-like round objects are centric diatoms in the genus Coscinodiscus. They can be large cells, getting up to 500 μm in diameter. Coscinodiscus is in some ways the quintessential centric diatom, as you will see below.
Take a look at these objects:
Clearly, one is a circle and one is a rectangle, right? Well, yes, but these two objects are the same type of thing—they are both cells of Coscinodiscus. The easiest way to understand diatom anatomy is to think of the frustule (the outer skeleton of the cell) of Coscinodiscus as being constructed like a petri dish. Because that’s actually what it is: an outer casing of silica with two halves, one of which fits over the other exactly the way a petri dish lid fits over the bottom of the petri dish. If you place a petri dish on a table and look down on it, you will see a circle. But if you pick up the petri dish and look at it from a side view, you will see a rectangle. If you don’t believe me, go ahead and try it with any canned food item in your pantry. Coscinodiscus is the same. If it lands on the microscope slide lying flat, it will look like a circle; this is called the valve view because you are looking down on the surface of one of the two valves of the frustule. Most of time when we see Coscinodiscus we see it in valve view. Sometimes you get lucky and a cell remains “standing up” even after you drop a cover slip on top of your sample, and you see the cell as a rectangle. This is called the girdle view. So in the photo above, what you see on the left is a Coscinodiscus cell in valve view, and what you see on the right is the same type of cell in girdle view. Same object, two perspectives, and two shapes. By the way, this is the answer to the question posed in the previous post.
And this is what a valve view of Coscinodiscus looks like when you zoom in:
You can see some of the sculpturing on the frustule, and the beautiful golden-brown color of diatoms. The diatoms are related to the brown algae and share the same overall set of photosynthetic pigments, which explains why diatoms are often the same colors as kelps.
Another of the common diatoms around here are those in the genus Chaetoceros. The prefix ‘chaet-‘ means ‘bristle’, and the cells of Chaetoceros have long bristles. Unlike Coscinodiscus, Chaetoceros forms chains. Some species form straight chains, others form spiraling chains, and still others form a sort of meandering chain that is embedded in a tiny blob of mucilage. The cells below are forming a straight chain.
In addition to all of the diatoms, there were more dinoflagellates than I expected to see. Ceratium was very well represented, often in chains of two cells.
I was even able to capture some video of Ceratium cells swimming in the thin film of water under the coverslip. Dinoflagellates have two flagella: one wrapped in that groove, or “waistline”, and one that trails free. Usually it’s the trailing flagellum that’s easier to see, and if you watch you’ll be able to see it in each of the cells.
Protoperidinium was another common dinoflagellate in the sample. Unlike the diatoms and photoautotrophic dinoflagellates, which have that sort of golden-brown color, Protoperidinium is a heterotroph. It eats other unicellular protists by extruding its cytoplasm out of the holes in its cellulose skeletal plates and engulfing prey, similar to the way an amoeba feeds. Because it does not rely on photosynthesis for obtaining fixed carbon, Protoperidinium comes in colors that we typically don’t associate with photoautotrophs. Pink, red, and grayish brown are common colors. This time I saw several that were bright red.
So that’s a glimpse of springtime in the ocean. Now let’s look up!
Legend has it that the swallows return to San Juan Capistrano every year on March 19, which is St. Joseph’s day. I don’t pay attention to St. Joseph’s day, but I do pay attention to the vernal equinox every year and keep an eye out for the return of our swallows to the marine lab. We get both cliff swallows (Petrochelidon pyrrhonota) and barn swallows (Hirundo rustica) building mud nests on our buildings. Last year (2021) the cliff swallows showed up first, with the barn swallows arriving a few weeks later; I remember being worried that they might not show up at all.
This year the swallows returned right on schedule. I saw my first barn swallows on the day of the vernal equinox, 21 March 2022.
They are so pretty! I haven’t seen any nest-building yet, but did witness what might have been a territorial spat. The bird in the photo above is the one on the left that is retreating in the photo below
Look at that gorgeous outspread tail! Barn swallows migrate to North America from southern Mexico and Central America. The cliff swallows come all the way from South America; no wonder they’re a little late arriving in California! I think they’ll show up any day now, and both they and the barn swallows will begin daubing mud above doorways and under the eaves.
Somehow, no matter what else is going on and what the calendar says, it never feels like spring until the swallows are zooming around again. Spring is my favorite season, as there’s so much going on, and I begin to feel energized again with the longer days. I have a busy spring teaching schedule and don’t know how much time I’ll have to do fun things like look at plankton for the hell of it, but will try to slow down often enough to take note of what’s happening around me.
