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Monterey Bay is shaped like a backwards letter 'C', with Santa Cruz on the north end and the Monterey Peninsula on the south end. The top of the 'C' is comparatively smooth, while the bottom is punctuated by the Monterey Peninsula, which juts north from the city of Monterey. The most striking geologic feature is the Monterey Submarine Canyon, but of course you can't see that from land. It is crazy to realize that the canyon starts right off the jetty at Moss Landing. It is this proximity to deep water that makes the Monterey Bay Aquarium Research Institute (MBARI) so ideally situated.

Monterey Bay, California
© Google Maps

Separated by 40.2 km (= approximately 25 statute miles) as measured harbor to harbor, Santa Cruz and Monterey represent both the same and slightly different marine habitats. On a large scale they are both part of the California Current system, strongly affected and biologically defined by seasonal upwelling in the spring and summer months. On a finer scale they differ in a few ways, primarily geologic. The rock on the Santa Cruz end of the bay is a soft sand- or mudstone, and at sites like Natural Bridges can be easily eroded; you can scratch it with your thumbnail, and falling on it might give you a bruise but probably won't beat you up more than that. The rock of the Monterey Peninsula is much less forgiving: granite with large quartz crystals. Falling on that stuff can leave you with bruises and a bad case of rock rash; I usually end up bleeding from at least one laceration when I'm in the intertidal there.

Limpet on granite on the Monterey Peninsula
16 June 2018
© Allison J. Gong
Barnacles on mudstone in Santa Cruz
17 June 2018
© Allison J. Gong

The difference in rock type between the north and south ends of Monterey Bay also manifests in the tidepools themselves. The soft mud stone of the Santa Cruz erodes into small particles, which form nice soft sandy beaches. Small particles also remain suspended in water more so than larger ones, which affects water clarity. Larger and heavier particles, on the other hand, sink out of the water, so that the water column itself tends to be less murky. Clear water has some marked advantages over murky water. For example, light transmission is directly proportional to water clarity. Thus, all other factors being equal, photosynthetic organisms such as algae have access to more light, in waters above large-grained sand than those above finer sediments.

That being said, it is not always the case that clearer water is better. Remember Phragmatopoma californica, one of the worms I wrote about recently? They build tubes out of sand grains. However, it turns out that they are particular about the sand grains they use. If you were to examine a Phragmatopoma tube under a dissecting scope you'd see that all of the sand grains are the same size. Just how they select and sort the sand grains isn't understood, but somehow they manage to choose the particles they want and cement them together underwater. Phragmatopoma is one of the most conspicuous animals at Natural Bridges on the north side of Monterey Bay, forming large mounds of hundreds of individuals, yet very few live on the Monterey Peninsula. There are likely several reasons for this, but part of the explanation is that the sand grains are too big to be used in the worms' tubes.

I live in Santa Cruz, on the north end of the bay, and most of my intertidal excursions these days are to locations in Santa Cruz and north along the coast. I haven't spent nearly as much time as I'd like to in the tidepools on the Monterey Peninsula and locations further south. It's tough getting to a site an hour away, when the low tide is at dawn. And with my post-concussion syndrome I don't yet feel comfortable driving myself that far away and back. Fortunately for me, I am currently mentoring a student working on an independent study project, and she was willing to drive down to Asilomar last weekend. So I tagged along with her.

Monterey Peninsula
© Google Maps

Asilomar State Reserve is one of California's no-take marine protected areas (MPAs), where people can look and take pictures but are not allowed to remove anything, dead or alive. It is a glorious site. The water is clear and blue, and the biota is both similar to and different from that on the north side of the bay. I want to highlight some of the organisms that I see there, that are less common here on the north side.

Black abalone (Haliotis cracherodii) at Asilomar State Beach
16 June 2018
© Allison J. Gong

Abalone (Haliotis sp.) are not unheard of here. In fact, there is a black ab (H. cracherodii) at Natural Bridges that I've been keeping an eye on since 2015, tucked into a crevice and generally not visible except on a minus tide. And further north at Pigeon Point I have seen red abalone (H. rufescens), both living and empty shells. But I've never seen as many black abs as I saw at Asilomar. Standing in a depression about as big as my kitchen table, well above the water level, I easily counted at least 20 black abs. Some of them were as big as my hand. How many can you see in the photo above?

Black abalone (Haliotis cracherodii) at Asilomar State Beach
16 June 2018
© Allison J. Gong

Abalone are large herbivorous snails. They feed on macroalgae, both reds and browns. If they venture from the safety of their nooks and crannies they can chase (at a snail's pace) down algae, but then they are vulnerable to predators such as cabezons and sea otters. Abs that live in crevices, like these, have to rely on drift algae to come to them; they don't have the luxury of choosing what to eat. It's the age-old compromise between safety and food, one of the driving forces in foraging behavior.

While we have four species of anemones in the genus Anthopleura at the Santa Cruz end of the bay, as well as other anemones such as Epiactis, we don't have any in the genus Urticina--not intertidally, at least. I have seen Urticina anemones at Carmel, and last weekend saw what I think was U. coriacea. It was in a pool, and partially obscured by sand and its own pharynx.

The anemone Urticina coriacea at Asilomar State Beach
16 June 2018
© Allison J. Gong

It's own pharynx, you ask? Yes! Anemones are cnidarians, and as such have a two-way gut. This means that food is ingested and wastes are expelled via a single opening, which for politeness' sake we call a mouth even though it also functions as an anus. Sometimes, when an anemone is expelling wastes, it also turns out the top part of its pharynx. This is a temporary condition, and the pharynx will be returned to normal soon. The anemone in the picture above appears to be in the process of spitting out something fairly large and undigestible.

Here's another example of an anemone eating a big meal, this time of mussels.

Giant green anemone (Anthopleura xanthogrammica) snacking on a clump of mussels (Mytilus californianus) at Natural Bridges
17 June 2018
© Allison J. Gong

What do you think this thing (below) is?

Pista elongata at Asilomar State Beach
16 June 2018
© Allison J. Gong

I had at first misidentified these as something else, but have since been told that they are the tubes of another of those strange terebellid polychaete worms. This one is Pista elongata. As with many terebellids, P. elongata lives in a tube, the opening end of which is elaborated into a sort of basket. They reportedly range from British Columbia to San Diego. I think I've seen them at Carmel Point, but not at Point Piños, which I've visited more often. And I'm positive I've never seen it at Natural Bridges.

At Asilomar I saw some large clusters of P. elongata in the low intertidal. They are not clonal, to my knowledge, so these aggregations would form by gregarious settlement of competent larvae when they return to shore.

Cluster of Pista elongata at Asilomar State Beach
16 June 2018
© Allison J. Gong

One solitary ascidian that I saw at Asilomar is Clavelina huntsmani, the appropriately called lightbulb tunicate:

The "lightbulb tunicate" Clavelina huntsmani at Asilomar State Beach
16 June 2017
© Allison J. Gong

For people too young to remember what an incandescent light bulb looks like, they were made of clear or frosted glass. Inside the glass bulb were tungsten filaments, through which electricity flowed; the filaments heated up enough to emit light. In Clavelina, the two pink structures running down the length of each zooid resemble the filaments of an incandescent light bulb, but are in fact parts of the pharyngeal basket, the structure used for filter feeding.

We have neither Pista nor Clavelina in Santa Cruz--at least, I've never seen them. They remind me that although Santa Cruz and Monterey are part of the same ecosystem, they do not represent the same microhabitat. I'm pretty familiar with the intertidal floral and fauna in Santa Cruz, but I absolutely love exploring the intertidal along the Monterey Peninsula. There's something exciting about spending time a place I don't know as well as the back of my hand. I hope that as my brain continues to heal I'll eventually regain the stamina to travel so far for a low tide.

This weekend I was supposed to take a photographer and his assistant into the field to hunt for staurozoans. I mean a real photographer, one who has worked for National Geographic. He also wrote the book One Cubic Foot. You may have heard of the guy. His name is David Liittschwager. Anyway, his assistant contacted me back in March, saying that he was working on something jellyfish-related for Nat Geo and hoped to include staurozoans in the story, and did I know anything about them? As in, maybe know where to find them? It just so happens that I do indeed know where to find staurozoans, at least sometimes, and we made a date to go hunting on a low tide. Then early in May the assistant contacted me to let me know that David's schedule had changed and he couldn't meet me today, and she hoped they'd be able to work with me in the future, and so on.

None of which means that I wouldn't go look for them anyways. I'd made the plans, the tide would still be fantastic, and so I went. And besides, these are staurozoans we're talking about! I will go out of my way to look for them as often as I can. Not only that, but I hadn't been to Franklin Point at all in 2018 and that certainly needed to be remedied.

Pigeon Point, viewed from Franklin Point trail
19 May 2018
© Allison J. Gong

The sand has definitely returned. The beach is a lot less steep than it was in the winter, and some of the rocks are completely covered again. This meant that the channels where staurozoans would likely be found are shallower and easier to search. But you still have to know where to look.

Tidal area at Franklin Point
19 May 2018
© Allison J. Gong

See that large pool? That's where the staurozoans live. They like areas where the water constantly moves back and forth, which makes them difficult to photograph in situ. And given that the big ones are about 2 cm in diameter and most of them are the same color as the algae they're attached to, they're a challenge to find in the first place. I looked for a long time and was about to give up on my search image when I found a single small staurozoan, about 10 mm in diameter, quite by accident. It was a golden-brown color, quite happily living in a surge channel. I took several very lousy pictures of it before coming up with the bright idea of moving it up the beach a bit to an area where the water wasn't moving quite as much. I sloshed up a few steps and found a likely spot, then placed my staurozoan where the water was deep enough for me to submerge the camera and take pictures.

Staurozoan (Haliclystus sp.) at Franklin Point
19 May 2018
© Allison J. Gong
Staurozoan (Haliclystus sp.) at Franklin Point
19 May 2018
© Allison J. Gong

Cute little thing, isn't it? I had my head down taking pictures of this animal, congratulating myself on having found it. When I looked around me I saw that I had inadvertently discovered a whole neighborhood of staurozoans. They were all around me! And some of them were quite large, a little over 2 cm in diameter. All of a sudden I couldn't not see them.

Staurozoan (Haliclystus sp.) at Franklin Point
19 May 2018
© Allison J. Gong

I know I've seen staurozoans in the same bottle green color as the Ulva, but this time I saw only brown ones. As you can see even the animals attached to Ulva were brown. Staurozoans seem to be solitary creatures. They are not permanently attached but do not aggregate and are not clonal. Most of the ones I found were as singles, although I did find a few loose clusters of 3-4 animals that just happened to be gathered in the same general vicinity.

Trio of staurozoans (Haliclystus sp.) at Franklin Point
19 May 2018
© Allison J. Gong

Not much is known about the biology of Haliclystus, or any of the staurozoans. I collected some one time many years ago, and brought them back to the lab for closer observation. They seemed to eat Artemia nauplii very readily, and I did get to observe some interesting behaviors, but they all died within a week or so. Given that I can find them only in certain places at Franklin Point, they must be picky about their living conditions. Obviously I can't provide what they need at the marine lab. The surging water movement, for example, is something that I can't easily replicate. I need to think about that. The mid-June low tides look extremely promising, and my collecting permit does allow me to collect staurozoans at Franklin Point. Maybe I'll be able to rig up something that better approximates their natural living conditions in the lab.

In the meantime, I just want to look at them.

Staurozoan (Haliclystus sp.) at Franklin Point
19 May 2018
© Allison J. Gong
Pair of staurozoans (Haliclystus sp) at Franklin Point
19 May 2018
© Allison J. Gong
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