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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.

3

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?

Male feather duster worm (Eudistylia polymorpha), spawning
2021-04-24
© Allison J. Gong

and

Male moonglow anemone (Anthopleura artemisia), spawning
2016-04-09
© Allison J. Gong

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

Here's a plankton sample in a bowl:

Live plankton sample
2022-03-21
© Allison J. Gong

And doesn't this radiolarian look like it belongs in Abell 370?

Live marine radiolarian under darkfield lighting
2020-05-06
© Allison J. Gong

Prawn Nebula

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.

Iridescent alga (Mazzaella flaccida) at Davenport Landing
2019-06-19
© Allison J. Gong

Baby stars

Hubble photographed this area of space, where new stars are being born, back in 2015. This region, designated NGC 2174, is in the constellation Orion.

Region NGC 2174, a star nursery, photographed by the Hubble Space Telescope in 2015
Public domain by NASA

At the peak of the summer growing season the sea lettuces (Ulva spp.) look similar.

Sea lettuce (Ulva sp.) at Franklin Point
2020-06-09
© Allison J. Gong

Jupiter

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.

Foam on the surface of a tide pool at Franklin Point
2021-04-29
© Allison J. Gong

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.

Kelps (Nereocystis luetkeana and Egregia menziesii) floating on a tide pool at Davenport Landing
2017-07-11
© Allison J. Gong
Ulva spawn on the surface of a tide pool at Franklin Point
2021-04-29
© Allison J. Gong

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.

3

Last night, 15 May 2022, there was a total lunar eclipse, which turned the full moon dark red. By the time the moon rose above the trees to the east the red phase was in full swing. I learned that it's extremely difficult to photograph what is essentially the new moon against the night sky.

Lunar eclipse
2022-05-15
© Allison J. Gong

I had better success once the moon started moving out of Earth's shadow and re-learned how to create photo montages. Some day I will remember how to do that and not have to learn it all over again. But the result is pretty nice!

Lunar eclipse
2022-05-15
© Allison J. Gong

And then I went to bed, because I'm not good at staying up late.

How did the eclipse show in your neck of the woods?

3

Brandt's cormorants (Urile penicillatus)
2022-05-01
© Allison J. Gong

It feels like forever since I've checked in on the cormorants at Natural Bridges. I simply haven't had time to mosey down there, take a gajillion photos, and then deal with them on the computer. But today I thought I'd give myself until lunch time to play with photos and such, before I hit the grindstone again and work on a lecture about the natural history of Big Sur.

And for the update: The Brandt's cormorants (Urile penicillatus) chicks are growing up! They're still mostly fluffy but some have a few feathers, and they're getting big now. I watched for about half an hour before realizing that the parents were feeding them; after that it was pretty easy to see when a feeding was imminent.

First, there's the behavior of the chick(s). Most of the time they are flopped like sacks of brown fluff, but when there's possible food they perk up and pay attention. It's funny how long their necks can be when stretched up! The chicks don't seem able to hold their heads up for very long yet. As we all know, however, food is a powerful motivator.

The parent also demonstrates what I think of as an about-to-regurgitate movements. It sort of reminds me of the cats' convulsions right before they hork up a hairball, only not as fast or violent. The parent cormorant stands up and sort of undulates front to back a few times, then bows low. This gets the chicks' attention and they start looking alert and expectant. The parent might go through the whole routine a few times before leaning towards the chick. The chick begins poking at the parent's bill, which seems to stimulate the actual regurgitation. Nom nom nom!

What I want to showcase this time is a series of photos showing a feeding session. The whole thing took about five seconds.

Large black birds in nests on rock. Chick pecking at parent's beak.
Brandt's cormorants (Urile penicillatus)
2022-05-01
© Allison J. Gong
Large black birds in nests on rock. Chick's head inside parent's mouth.
Brandt's cormorants (Urile penicillatus)
2022-05-01
© Allison J. Gong
Large black birds in nests on rock. Chick's head inside parent's mouth.
Brandt's cormorants (Urile penicillatus)
2022-05-01
© Allison J. Gong
Large black birds in nests on rock. Chick's head inside parent's mouth.
Brandt's cormorants (Urile penicillatus)
2022-05-01
© Allison J. Gong
Large black birds in nests on rock. Chick's head inside parent's mouth.
Brandt's cormorants (Urile penicillatus)
2022-05-01
© Allison J. Gong
Large black birds in nests on rock.
Brandt's cormorants (Urile penicillatus)
2022-05-01
© Allison J. Gong

Look at those stubby little wings! These youngsters have some growing to do and have to make real feathers before they can fledge. Maybe they'll have done so by the time I finish up with school for the year.

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.

Mixed marine plankton
Mixed plankton sample, collected from the Santa Cruz Municipal Wharf
2022-03-21
© Allison J. Gong

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:

Circular object with golden-brown spots
Coscinodiscus sp. under brightfield lighting, showing true colors
2022-03-21
© Allison J. Gong

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.

Chain of rectangular boxes, each containing amorphous golden blobs. Long bifurcating bristles protrude from the corners of the boxes.
Chaetoceros sp.
2022-03-21
© Allison J. Gong

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.

A golden cell with two points at one end and a single point at the other. Three golden ovoid cells in a chain.
Dinoflagellate (Ceratium lineatum, top) and an unidentified diatom
2022-03-21
© Allison J. Gong

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.

A disc-shaped object with a single point on one side and two points on the other side. Object contains small red blotches.
Protoperidinium, a heterotrophic dinoflagellate
2022-03-21
© Allison J. Gong

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.

Barn swallow (Hirundo rustica)
2022-03-21
© Allison J. Gong

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

Bird perched on a sign
Two barn swallows (Hirundo rustica) expressing a difference of opinion
2022-03-21
© Allison J. Gong

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.

5

For the second year in a row (that I am aware of, anyway), the Brandt's cormorants (Urile penicillatus) have claimed the last remaining arch at Natural Bridges as a breeding rookery. I remember being so excited at "discovering" them in 2021. Anyway, they're back again, building piles of algae into nests.

Rock with dozens of black birds, some sitting on nests of algae
Brandt's cormorants (Urile penicillatus) on top of the arch at Natural Bridges
2022-03-20
© Allison J. Gong

BTW, if you're keeping score at home, the genus name for the North Pacific cormorants has been changed from Phalacrocorax to Urile. A 2014 study showed this North Pacific group to be a sister clade to those in the genus Phalacrocorax, and in 2021 the International Ornithologists' Union formally adopted the genus Urile for them.

Adult cormorants with white breeding plumes on neck and back
Brandt's cormorant (Urile penicillatus)
2022-03-20
© Allison J. Gong

During the breeding season the Brandt's cormorants develop long, wispy white plumes on the cheeks and in two smaller tufts over the shoulder blades. In my head I've been calling them Einstein plumes because although they probably do have a real name, I don't know what it is. When you see a face portrait of one of these birds, you'll know what I mean.

Male cormorant bringing algae to mate on top of rock
Brandt's cormorants (Urile penicillatus)
2022-03-20
© Allison J. Gong

The color blue also features in the breeding phenotype of Brandt's cormorants. Cormorants are related to pelicans, which of course have that huge gular pouch that can hold gallons of water. The gular pouch of cormorants isn't nearly as large. For the Brandt's cormorants, the blue gular pouch indicates sexual maturity. And can you see the color of the eye of the bird that is bowing? The eye of a sexually mature bird turns a brilliant cobalt blue during the breeding season. Brandt's cormorants nest on rocks or cliffs, with the male gathering most of the nesting material. At Natural Bridges, the nests are made up mostly of algae, but I've seen a few birds flying by with surfgrass in their mouths. This male above has brought back a nice clump of red algae (a species of Cryptopleura, maybe?) to an appreciative mate.

So those are the Brandt's cormorants.

This year there is a second species of cormorant hanging out on the sides of the rock. These are pelagic cormorants (Urile pelagicus).

Three cormorants on rock cliff
Pelagic cormorants (Urile pelagicus) at Natural Bridges
2022-03-06
© Allison J. Gong

I first noticed the pelagic cormorants early in March. I saw those white patches on the flanks and thought, "But that's not the right body shape for a pigeon guillemot!" I came home, looked them up, and sure enough, they are pelagic cormorants. The pelagic is a little smaller and more slender than the Brandt's, and has a red face and glossy black-green plumage with the white rump patches during the breeding season. These three pelagic cormorants are on small ledges on the side of the same rock where the Brandt's cormorants are nesting, providing a nice demonstration of resource partitioning.

So, are these pelagic cormorants really the new kids on the rock? Going by my photographs from 2021, I'd say yes. I looked back through the photos I took when I discovered the Brandt's cormorants, and did not see pelagic cormorants in any of them. Of course, absence of evidence is not necessarily evidence of absence, and it could very well be that the pelagics have been there all along with the Brandt's and I simply never noticed them. Given that my area of expertise is absolutely not birds, I'm quite prepared to learn that I am wrong about this. But the pelagic cormorants are new to me, and that's reason enough to be delighted by them.

Over the past couple of weeks I've rented two super telephoto lenses, to see what all the hype was about. I mean, do I really need 500 or 600mm of reach? I had read up on the specs of such lenses, and one major drawback is the weight—1900 grams or more. Would I be willing to lug a beast like this around, and would I be able to use it effectively? You never know until you try, so I rented them. And, of course, it was foggy both weeks so I didn't have much opportunity to take decent photos. But since the entire point of renting the lenses was to see if I could use them at all, that was fine.

As part of the test-drive for the second lens, I went up to Waddell Beach to see if there would be any birds to photograph. It is migration season, and our winter residents will be arriving soon. Some of them, such as the red-necked phalarope, have shown up at Younger Lagoon over the past four weeks or so. It was really foggy at Waddell, remember, and I didn't have much hope of seeing anything remarkable. There were some gulls and whimbrels off in the distance. But it turned out that the stars of the show were blackbirds!

They were hard to miss, because there were 50-60 of them and they were hopping up and down like jumping beans.

This is a mixed flock of Brewer's blackbirds (Euphagus cyanocephalus) and red-winged blackbirds (Agelaius phoenicius). The glossy greenish-black birds are the male Brewer's blackbirds, and most of the brownish birds are female Brewer's blackbirds. Since both sexes were doing the hopping, I didn't think this behavior had to do with courtship or mating.

So yes, while most of the birds seemed to be Brewer's blackbirds, I did hear the liquid gurgling of the red-winged blackbird's song coming from somewhere in the flock. When I got home and looked at the photos on the big monitor, I did see some red-winged blackbirds. Here's a male, surrounded by other males red-wingeds and both female and male Brewer's blackbirds.

Male red-winged blackbird (Agelaius phoenicius) at Waddell Beach
2021-09-14
© Allison J. Gong

In this photo above the black birds are male Brewer's blackbirds. The brown birds without faint wing bars are female Brewer's blackbirds, and the brown birds with the wing bars are male red-wingeds. There were no female red-winged blackbirds in any of my photos. According to an article from Cornell's Bird Academy, the males spend the weeks leading up to springtime competing for territories, and when the females return from their winter migration they will choose mates based partly on the quality of the territory. Mid-September is too early for this kind of competition, though. We are just about up to the autumn equinox, but not near winter quite yet.

Back to the hopping. There's a clue in this photo about what I think was going on:

Male Brewer's blackbird (Euphagus cyanocephalus) at Waddell Beach
2021-09-14
© Allison J. Gong

See that little fly? There were many such flies, most of which were lower on the beach gathering around the kelps and other wet detritus that had washed up. There were fewer flies up where the driftwood accumulates, though. Once again, it wasn't until I saw the pictures on my big monitor that I could figure out what those blackbirds were doing. They were hopping up to eat flies!

Here's a series of shots showing one of the male red-wingeds in mid-hop.

  • Looking up, just before the hop:
Male red-winged blackbird (Agelaius phoenicius) at Waddell Beach
2021-09-14
© Allison J. Gong
  • Up he goes! See the very edge of the red epaulette on his right wing? And all those flies?
Male red-winged blackbird (Agelaius phoenicius) at Waddell Beach
2021-09-14
© Allison J. Gong
  • Is he going to catch something?
Male red-winged blackbird (Agelaius phoenicius) at Waddell Beach
2021-09-14
© Allison J. Gong
  • Maybe?
Male red-winged blackbird (Agelaius phoenicius) at Waddell Beach
2021-09-14
© Allison J. Gong
  • After all that, I'm not at all sure if he actually got anything!
Male red-winged blackbird (Agelaius phoenicius) at Waddell Beach
2021-09-14
© Allison J. Gong

I don't have any hard evidence that the blackbirds (both Brewer's and red-wingeds) are catching flies. And while I was at the beach watching them hopping up and down I had no idea what they were doing. However, now that I've seen the flies in the photos, it makes sense that the birds would be hopping up to catch and eat them, especially since both sexes of the Brewer's blackbirds were doing the same thing.

So that's what was hoppening at the beach!

3

Way back in 2015 I wrote about some Ulva that spawned in a bowl at the lab, and delved into the mysteries of reproduction in the green algae. This morning I was out at Franklin Point and saw this:

Spawning algae at Franklin Point
2021-04-01
© Allison J. Gong

I had seen the sea lettuces (Ulva spp.) spawning in these high pools at Franklin Point before, and usually cursed the murkiness of the water. But today the water was dead calm, with the tide low enough that there were no waves to slosh into the pools. The result was a gorgeous marbled swirl in the water. The patterns were stunning.

Yellow streams of algal spawn in a shallow tidepool
Spawning algae at Franklin Point
2021-04-01
© Allison J. Gong
Yellow streams of algal spawn in a shallow tidepool
Spawning algae at Franklin Point
2021-04-01
© Allison J. Gong
Yellow streams of algal spawn in a shallow tidepool
Spawning algae at Franklin Point
2021-04-01
© Allison J. Gong

What these photos show is the Ulva releasing either spores or gametes. Without microscopic examination it's impossible for me to know whether these tiny cells are spores or gametes. What I can say is that the spawn is released from the distal ends of the thallus, making the body of the alga look ragged.

Sea lettuce in a tidepool. Some blades are clear.
Sea lettuce (Ulva sp.) at the edge of a tidepool at Franklin Point
2021-04-01
© Allison J. Gong

The parts of the thallus that have already spawned are now clear. The tissue itself will soon disintegrate, leaving behind only the healthy green parts, which should be able to regrow.

All of these photos were taken in pools where the spawning itself had either completely or mostly stopped. Obviously when the tide comes back all of this yellow spooge will get mixed up. It's only when the water is perfectly still that these streams would form. It was hard stepping around the pools to take the photos, as the last thing I wanted to do was stomp my big booted foot into a pool and disrupt the beautiful patterns. Fortunately the sun angle was a little cooperative this morning, and I was able to find a pool where active spawning was happening.

What appears to be an act of destruction—the alga's brilliant green thallus being reduced to yellow streaks that drift away with the tide—is really an act of procreation. This is terminal reproduction, literally the last thing an organism does before it dies. Salmon do this, as do annual plants. The sheer amount of algal spawn in these tidepools is astounding. Imagine the number of 2-micron cells needed to color the water to this degree. But if reproducing is the last thing you're going to do in your life, you might as well go all in on your way out, right?

A utility pole across the street and one house down has, for years, been an object of interest for a variety of birds. The hairy and downy woodpeckers drum on it in the spring, and various songbirds hang out and rest on the top. About a month ago now I saw a raptor up there, eating something. It was a female merlin (Falco columbarius). According to Cornell's All About Birds, merlins are in our area during the nonbreeding season, but I've never been certain about having seen one.

On the morning of Saturday 13 March I went outside to look around, and saw a bird on the pole. It appeared to be either eating or cleaning its beak. I ran inside to grab the camera, which fortunately had my longest lens and the 1.4x teleconverter attached, and snapped off a bunch of shots. The sun was rising, but I was able to get some decent photos of the bird even though from the best vantage point it was backlit.

Clearly, he's eating something:

Male merlin (Falco columbarius)
2021-03-13
© Allison J. Gong

But what is it eating? Rodent bits?

Male merlin (Falco columbarius)
2021-03-13
© Allison J. Gong

No, look at that foot. It's a bird!

Male merlin (Falco columbarius)
2021-03-13
© Allison J. Gong

Yep. Definitely a bird.

Male merlin (Falco columbarius)
2021-03-13
© Allison J. Gong

And here he is, taking a break between courses:

Male merlin (Falco columbarius)
2021-03-13
© Allison J. Gong

Merlins are members of the falcon family. Smaller birds make up the majority of a merlin's prey, but they also eat large insects such as grasshoppers. As with peregrine falcons, merlin populations were severely reduced in the years when DDT was widely used to keep insect populations down, but they have since recovered. Truly, the recovery of birds of prey after DDT was banned is one of the great successes of conservation biology.

There were feathers in the street below the pole. I assume they are from the merlin's prey, as when I looked at the top of the pole through binoculars I could see the same sort of feathers up there. I compared the feathers with photos on a few ID sites, but it's no easy identifying feathers without any additional context. Someone suggested that they might be from a male house finch. We have lots of those around all the time, so that's probably the best guess possible.

Feathers from prey of a merlin (Falco columbarius)
2021-03-13
© Allison J. Gong

So there you have it: Saturday brunch with songbird on the menu!

1

For several weeks now I've been raising another batch of bat star (Patiria miniata) larvae, from a fortuitous spawning that occurred in early January. Since this is rather old hat by now I'm not diligently taking photos or drawing the larvae as often as I would have years ago when this kind of undertaking was new to me. But I still change the water twice a week and look at them on Fridays, and I still have the set-up that attaches my old phone to the microscope so I can take pictures of them.

Last Friday it occurred to me that: (A) my gizmo holds the camera steady over the microscope, so I can take pictures at multiple focal planes within objects under the scope; and (B) I have software that will stitch those many snapshots into a single image. Neat!

So I made this:

Bipinnaria larva of the sea star Patiria miniata, age 44 days
44-day-old larva of the bat star, Patiria miniata
2021-02-19
© Allison J. Gong

This larval stage is called a bipinnaria or a brachiolaria. From top (anterior end) to bottom (posterior end) the larva is about 1 mm long. It swims with the anterior end in front. In some sea stars the bipinnaria grows long arms, at which point we call it a brachiolaria ('brachio' = 'arm' in Greek). Bat stars don't grow long arms, so the distinction between bipinnaria and brachiolaria is much fuzzier.

I took 11 photos of this larva, each one focused on a different horizontal plane, and did a focus merge in my photo processing software. Crossed my fingers as the software did its magic, and then peeked at the result. It worked! When looking through the microscope I have to focus up and down through the body to get an idea of its three-dimensional structure. But if the animal holds still long enough, I can do the focus merge thing and get images like this one.

And that slight halo that you see around the exterior surfaces of the larva? That is not an artifact of the photo taking or processing. That halo is due to the cilia that cover the body. There is a ciliated band, which you can see as the dark gold ribbon that snakes along the lobes of the body, and the other body surfaces are ciliated as well. The ciliated band is what the larva uses to swim through the water. Each photo freezes the ciliary action at the moment it was shot, but stitching several photos together causes the cilia to blur into that pale halo.

Nifty!

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