Last month I spent four days in the town of Egmont, BC. My husband and I had joined a friend on his annual excursion to the stomping grounds of his youth. We trailered the friend’s boat, Scherzo, up through Oregon and Washington and into British Columbia. We took a ferry and then ditched the car in Sechelt, piled our belongings and food into Scherzo, and headed up the Sechelt Inlet to arrive in Egmont. Incidentally, Egmont is entirely reachable by road, but it was kind of cool showing up in a little boat to the dock of the house we had rented.
On our way up Sechelt Inlet I had noticed quite a bit of brown scum on the surface of the water. I couldn’t collect any on my hands and it didn’t have a detectable odor, but some of my cerebral neurons did their job and the name Noctiluca came into my head. Noctiluca scintillans is a bioluminescent dinoflagellate. It is a regular component of the plankton in Monterey Bay at this time of year. What makes it distinct from other dinoflagellates are its large size (can be greater than 1mm in diameter) and the fact that its hydrophobic theca (cell wall) causes cells to get stuck at the surface of the water. They can look like tiny bubbles floating at the surface.
There wasn’t as much Noctiluca at our dock in Egmont as we’d seen on our way up the inlet, but it was worth going out at night just to see. Dinoflagellates and other bioluminescent critters light up when disturbed. We borrowed Scherzo‘s oar to disturb the water and see what happened. We could see light when Alex drew the oar back and forth in the water, but a washing machine-like agitation was the best for getting the cells to flash.
Bioluminescence is one of those phenomena that never gets tiring. In this case, each Noctiluca cell emits one tiny flash of light when it gets bumped. These photos give you an idea of how dense the population was. Dinoflagellates tend to be late-season bloomers, becoming more abundant than the diatoms that dominate the spring and early summer phytoplankton. Many dinoflagellates, despite being considered part of the phytoplankton, are heterotrophic either in addition to or instead of being autotrophic (photosynthetic). Noctiluca is one of the heterotrophic dinoflagellates. It preys on smaller cells, including diatoms, small invertebrate larvae, and fish eggs.
If I had been at home with my lab supplies at hand I would have collected some of the cells in a scintillation vial, brought them into a dark room in the house, and shaken them up to observe the bioluminescence under controlled conditions. As it was, seeing it in the field, so to speak, was really cool.
Last weekend the fabled Western Flyer came home to Monterey for a brief visit. For anyone who doesn’t recognize the name, the WesternFlyer is the boat that Ed Ricketts and John Steinbeck took to the Sea of Cortez in 1940. At the time of the trip she was just another purse seiner in Monterey, and after the collapse of the sardine fishery she passed through several owners’ hands and was outfitted first as a deep water trawler and then as a crab boat. Several decades passed, and in 2012 the boat, now named the Gemini, sank near Anacortes, WA. She was refloated and sank again in early 2013. This time she was left on the bottom for several months. In June 2013 she was refloated again and taken to dry dock in Port Townsend, WA, where she sat for a couple of years until she was purchased and the long journey towards restoration began. The Western Flyer Foundation has more about the acquisition, restoration, and new purpose of this boat.
Fast forward to 2023, and it was time for the Western Flyer (somewhere along the way she was rechristened to her original name) to return to California. The majority of the work to restore her (woodwork, mechanical engine stuff, etc.) was done up in Washington, which was fitting because she was originally built in Tacoma. She had to come down to California, however, to be kitted out to do science. And she will live here and work out of Monterey.
On Saturday 4 November 2023, the public was invited to welcome the Western Flyer to Monterey. It was a big event, with a boat parade, a decorated boat contest, and much speechifying. The plan was for boats to gather outside the Monterey harbor and wait until the Flyer arrived from Moss Landing with her escort, wait until she was berthed in her temporary spot in the marina, and then parade past her and wherever the judges were. I never did quite figure out where that was. We trailered our friend Murray’s boat, Scherzo, down to Monterey to see the Flyer and tootle along in the boat parade. Scherzo has her own stories to tell, as she was built in Murray’s backyard over a period of several years. Murray was unable to join us, so it was just Alex and me in the boat parade aboard Scherzo.
It was hard to count the boats out on the bay waiting for the Flyer, but there were about 40. We were in the middle of the pack. Most of the boats were sailboats but there were a few motorboats and one research vessel along for the ride. Scherzo was definitely the only little boat!
Given our position in the middle of the boat scrum, we didn’t get a very good view of the Flyer when she arrived. But once she got into the harbor, the fireboat escort made it easier to see where she was.
We were instructed to wait outside the harbor until the Flyer was docked, and then position ourselves into single queue. Being quite ignorant about how these things are done, I imagined that getting ~40 vessels of various sizes and propulsion systems, all bobbing around in Monterey Bay, into a single-file line would be like herding cats, but it was very well organized. Clearly these boat captains know what they’re doing.
And how was I doing with my infamous seasickness, you ask? I was hopped up on Dramamine, the only drug that works for me. And I was fine while on the water. After that, though, the sleepiness took hold and I had to take a nap on a park bench.
The Flyer was docked at about noon, and the speechifying began. Tours of the boat would start at 13:00 and end at 16:00. We left to get some lunch, hoping to beat the crowd, and came back at around 14:00 to find that there were still hordes of people waiting to go aboard. So we took Scherzo out for another tootle, first cruising around the harbor to get some nice shots of the Flyer.
Western Flyer, docked in MontereyWestern Flyer, docked in Monterey
We still had time to kill, so we left the harbor and went down the coast as far as the Monterey Bay Aquarium, stopping to look at sea otters and murres. Then we looked at the time and saw that it was about 15:30, so we turned around and high-tailed it back to the harbor. We got Scherzo out of the water and ran over to the Flyer. By my watch it was 15:58, so I convinced the volunteer to let us get in line.
Even at the end of the public access period, it took about 45 minutes for us to get onto the boat. Once aboard, we could wander around and take pictures of pretty much everything. My eye, as usual, was drawn to the less obvious things.
This gentleman wearing the colors of the Italian flag, was explaining how purse seiners work. This display was on the rear deck, directly above what was originally the fish hold.
We were not allowed to go below decks into the fish hold, because that’s the part of the boat that isn’t finished yet. The aft section of the hold will be the science lab and will eventually be kitted out with microscopes and a small library. I imagine there will be computers, too.
One of my favorite bits of the boat was this wooden turtle inlaid on the aft deck. It wasn’t until we got home that I remembered this passage from Sea of Cortez:
They hung the turtle to a stay where it waved its flippers helplessly and stretched its old wrinkled neck and gnashed its parrot beak. The small dark eyes had a quizzical pained look and a quantity of blood emerged from the pierced shell. . . . And now a strange and terrible bit of knowledge came to Tiny; turtles are very hard to kill. Cutting off the head seems to have little immediate effect. This turtle was as lively as it had been, and a large quantity of very red blood poured from the trunk of the neck. The flippers waived frantically and there was none of the constricting motion of a decapitated animal.
Steinbeck, John, and Edward Flanders Ricketts. Sea of Cortez, The Viking Press, New York, 1941.
I didn’t think at the time to ask, but I bet this inlaid turtle marks the spot where the hawksbill turtle came to its unfortunate end.
Inside the cabin we could see just how crowded things were, for a total of seven people on a 6-week expedition. There were three pairs of narrow bunks for scientists and crew, and a separate room for the captain behind the wheelhouse. There would be no privacy.
The galley, on the other hand, felt rather spacious. The modern Western Flyer has a nifty modern fridge unit and seems well arranged to maximize usable space. The coolest part was the stove, which is the same model (although not the same exact unit) as in the original Flyer. It runs on diesel fuel and would have done a great job of heating the cabin area.
The Western Flyer was in Monterey for another day (Sunday), so visitors could come and take pictures of her, but no additional tours were allowed. Then on Monday she went back up to Moss Landing. She will be there for about six months, for the installation of the science lab. After that, the Western Flyer goes back to school. She will take students on cruises, to study oceanography and marine biology, combined with the arts and humanities, with the goal of fostering curiosity about the natural world. The Western Flyer Foundation offers these educational programs free of charge. If you would like to contribute to this endeavor, please consider donating to the Western Flyer Foundation.
Yesterday, 30 June 2023, was deemed by the National Museum of Natural History to be International Polychaete Day, and the Smithsonian had an entire day of talks and activities for visitors to learn about the marine segmented worms. And you know me: I’m in favor of any event that draws attention to the animals that are not like us. So this is my own little celebration of worms I encountered over this past week.
Living with sea stars
I’ve written before about how many of the bat stars (Patiria miniata) I see at Pigeon Point carry small commensal polychaetes on their oral surface, often associated with the ambulacral groove. Several taxa of echinoderms are known to have associations with polychaetes, and I’ve seen worms crawling around on sea stars, sea urchins, and sea cucumbers. Oxydromus pugettensis is the polychaete I’ve seen on the bat stars in the field.
Years ago now, I collected some bat stars to bring back to the lab. Some of them had worms, and I was interested in seeing how long the worms stuck around once the stars were in captivity. The answer was “Not very long.” I seem to remember that the stars had lost their worms within a week. And since then, despite having many bat stars come through my hands at the lab, none of them have acquired worms.
Until now. This past week I was moving stars around and cleaning tables after flushing seawater pipes. I have a large bat star and a smaller one running feral in one of the tables. I picked up the larger star and turned it over just to check on it, and saw a dark squiggly thing. It was a worm!
This is the first time I have ever seen a sea star acquire a commensal worm. It’s gotta happen, because we see worms on stars in nature. But I do wonder about this relationship. The worms are highly mobile and probably leave one star and join another quite frequently, or remain free-living (i.e., not on a host star). I had brought in some algae the previous week, and it’s quite possible that the worm came along as bycatch and found its way to the bat star. I checked on the star later in the week, and did not see the worm. It hadn’t joined the smaller of the bat stars, either.
Baby worms
This past Monday I did a plankton tow off the end of the Santa Cruz Municipal Wharf. This was my first plankton tow of the year, and I wanted to see what was there. The water was very clear and the phytoplankton were lacking, but there was a decent diversity within the zooplankton. Of particular interest to this report were the baby worms.
Baby worms are present in any plankton tow collected at any time of the year, although they may be more abundant at some times compared to others. Clearly there isn’t much seasonality to reproduction in some of our local polychaetes. The most commonly seen baby worms in plankton samples are the metatrochophores of worms in the family Spionidae.
Adult spionids are benthic and live in tubes. They have two long palps that extend from the anterior end and are typically used to scrape up organic deposits from the area surrounding the tube. Like most polychaetes, spionids are broadcast spawners that cast gametes out into the water, where fertilization and development occur. Polychaetes go through a larval phase called a trochophore, defined by a ring of cilia (the prototroch) that produces the feeding current for the animal. Incidentally, many molluscs also go through a trochophore stage, but that’s a story for another time. Some polychaetes, including the spionids, have a second planktonic stage called a metatrochophore. The metatrochophore is a much larger and more elaborate version of the trochophore, with eyespots and few to many segments complete with associated bristles. They can crawl as well as swim. Some of them can be 3 mm long, which is pretty big for something that is still up in the plankton. The spionid metatrochophore also has the two long palps, which sometimes remind me of the flaps on Elmer Fudd’s hat.
These are photos of the same individual worm. It’s about 2 mm long, a little longer if all stretched out.
There was another type of polychaete metatrochophore in the sample, but I don’t recognize which family this one comes from. I should, because I see it frequently enough to know it isn’t unusual. It might be a young phyllodocid metatrochophore, but that’s just a guess. Anyhow, this creature has fewer segments than the spionid metatrochophore and lacks the spionid’s long palps. It does have eyespots, segments with bristles, and (I think) two pairs of tentacles associated with the head region. This individual also contains a lot of oil droplets, visible as those small dark circles in the dorsal half of the body behind the head. Oil droplets serve as energy stores and flotation devices. Many marine invertebrate larvae stockpile calories as they feed and store them in oil. In some cases, these calories are needed to sustain a later larval stage that doesn’t feed.
There you have it, my belated contribution to International Polychaete Day 2023. I always enjoy finding worms in our plankton. They have a lot of personality, and it’s fun to watch them zooming around. They are really fast swimmers, and I have to squash them under a coverslip—just a little—to get them to hold still long enough to take photos. Always worth the effort, though!
Ask any marine biology student to list some interesting factoids about barnacles, and one of them should be “Barnacles are benthic and sessile” by which they mean that barnacles live their entire lives glued to a single spot. This definitely describes what it means to be benthic. Barnacles are indeed stuck, for better or worse, to the location that their cyprid larva selected. Once the cyprid glues its head to the rock or other hard substrate, that’s it. A bad choice could mean that the barnacle starves, desiccates, or is unable to mate. A good choice means an opportunity to live long and prosper.
How is it, then, that we have things that are called pelagic barnacles? These are barnacles that live permanently attached to objects that move through the water. The objects can be living (e.g., whales or turtles) or non-living (e.g., boats). Pelagic barnacles are not just traveling versions of the species we see in the intertidal or on docks and pilings—they are different species altogether.
Yesterday morning I went to Younger Lagoon to see what had happened during the most recent storm. The lagoon had once again breached through to the ocean, and bits of Monterey Bay were sloshing into the lagoon. None of that was unexpected.
What did catch my eye were the fuzzy blotches on some of the pieces of wood that had washed up onto the beach.
A closer look confirmed my thought that these were pelagic barnacles in the genus Lepas. These are a type of gooseneck barnacle, similar in overall morphology to the very common intertidal Pollicpes polymerus.
These barnacles were small, and having been emersed for at least several hours were definitely not looking their best. They didn’t smell dead just yet, but since they had zero chance of getting back into the water before the next high tide, were doomed. A few of them had their cirri—the modified thoracic appendages that barnacles sweep through the water when feeding—extended, which I’ve seen before with barnacles on their last leg. See what I did there? I did touch some of the cirri, and the barnacles did not respond at all, although they had not yet dried out to the point of crispiness.
Lepas makes a living attached to objects that float in the ocean. I usually see them on logs or smaller pieces of wood, as they are here, but do occasionally find tiny ones on the blades of giant kelp (Macrocystis pyrifera). Living attached to objects that float with the currents means the barnacles are constantly moving through the water, able to feed 24/7 without the constraints of high and low tide. Compared to the robust gooseneck and acorn barnacles of the rocky intertidal, Lepas is translucent and delicate, with plates that are only weakly calcified. Given its lifestyle, Lepas rarely has to withstand bashing surf or waves; by the time it does, its substrate is inevitably headed onto shore, where the barnacles will die anyway.
So there you have it—a barnacle that flouts the rule and manages to be both benthic and pelagic. Or perhaps I should say that it is benthic but has a pelagic lifestyle. Either way, Lepas is making the best of both worlds, isn’t it?
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.
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.
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.
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.
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!
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.
