The best of both worlds. . . until it isn’t

Posted on by Allison J. Gong

One of the important distinctions that my marine biology students learn about is the difference between organisms that are benthic and those that are pelagic. Organisms described as benthic live attached to or associated with a surface, often but not always the sea floor. In addition to the stationary sea floor itself, benthic organisms can be attached to objects that move, such as boulders, boats, and other organisms. Nor are all benthic organisms incapable of movement, either crawling/walking or swimming. Think of crabs, snails, etc. Even anemones can creep about very slowly. Lots of fish are also benthic, although ichthyologists use the term “demersal” rather than “benthic”. Flatfish don’t spend much time at all away from the sea floor once they metamorphose into the juvenile form. Sculpins can flit about in the intertidal, but they lack a swim bladder and tend to sink to the bottom of tidepools. The algae, in their multicellular life history stages, are for the most part all benthic even though they have spores and/or gametes that disperse via water currents.

Pelagic organisms, both large and small, live in the water column away from the sea floor or any other surface. We further categorize pelagic creatures based on how well they can swim:

  • Nekton — organisms that are strong enough to swim against currents, such as most fish, the tetrapod vertebrates, and the large squids
  • Plankton — organisms that are either too big or weak to swim against currents and drift where the currents take them; we tend to assume that plankton are all tiny creatures, but there are some very large members of the jelly plankton, too

Returning to the matter at hand, it turns out that these distinctions are nowhere as clear as I’ve made them out to be. In biology, categorization of just about anything is messier than you might expect and can be downright frustrating for people who like everything to be in its own discrete box and to remain there in perpetuity.

For today’s example, we have what at first glance should be a nice clear distinction: An organism is either benthic or pelagic. Except that sometimes the organism itself might be entirely benthic—sessile, even—while the surface it is attached to might be pelagic. Most of the biota that gets scraped off the bottom of a boat consists of benthic animals and algae stuck onto an object that frequently moves through the water. The large acorn barnacles encrusting the shells of sea turtles or the skin of gray and humpback whales are sessile animals while also living the pelagic lifestyle.

We have a few species of pelagic barnacle in California, and I’ve written about them before. Occasionally they wash up onto beaches, where they inevitably desiccate and die.

Last week I saw this in the intertidal:

Brown stipe of kelp with torn blades, on background of sand
Frond of Macrocystis pyrifera, washed onto beach
© Allison J. Gong
2026-06-18

Looks like your bog standard piece of ratty kelp, right? Except that a closer peek revealed this:

Gray triangular objects on a brown corrugated surface
Pelagic barnacles (Lepas pacifica) on blade of Macrocystis pyrifera
© Allison J. Gong
2026-06-18

Now, these barnacles thought they had it good. They’ve formed a small village (my chosen collective noun for barnacles) so they can copulate when the time comes. They are filter feeders that depend on water currents to bring food close enough to be captured by their claw-like cirri, which are modified thoracic appendages. Since these barnacles are stuck permanently to kelp, they rely on movement of kelp fronds through the water to feed. Conveniently for them, kelp fronds sway back and forth pretty continuously. So, these Lepas barnacles have the best of both worlds.

Until the kelp stipe breaks and the frond floats away. We had a very strong south swell come through the area last week, and a lot of algae had been washed up onto local beaches. We’re still in June, which is too early for the Macrocystis thalli to be senescing already, so I think the swell is to blame for the carnage. In any case, it’s lights out for these Lepas that came along for the ride.

These particular barnacles were still alive, at least for a little while that morning. Once on the beach their demise is inevitable. As is the case for most things living in the wild, life is unpredictable and difficult, and it behooves an organism to grab whatever advantage presents itself. Individuals in this group of Lepas made the short-term decision to take up residence in a village of conspecifics (although I always wonder: what caused the very first Lepas larva to choose this particular bit of kelp, and how how likely is it that any others would ever join it?). They were able to thrive there for long enough for some of them to reach what is likely adult size. Hopefully some of the larger individuals were able to copulate and release their larvae into the water column before this lot ended up on the beach, to give the next generation a chance.

Six months, and a big return

Posted on by Allison J. Gong

Next week I will be six months beyond a total replacement of my right knee. The rehab has been long and tough, and I’m nowhere near the end yet. I’ve been told by my surgeon to expect a 12- to 18-month recovery to get back to whatever my new normal will be. By that estimate I’m either 1/3 or 1/2 of the way there; given the way things are going I suspect it’s the smaller fraction, so I’m looking at another year of ongoing, slow improvement.

I’ve finally gotten strong enough that I felt ready to return to the intertidal. And yesterday being the first day of a new year, it seemed fitting to venture out into my old life again. I chose a site that didn’t involve any cliff-climbing (not quite up to that yet), but did have stairs so I could challenge the knee. Down is still hard, but up is a piece of cake now.

Two people standing among dark rocks. Person in the front is wearing a bright pink jacket and holding a green rectangular object. Person in the midground is wearing a black jacket and green knee-high boots. There is a lighthouse in the background.
My friend, Sara, and me on the rocks at Whaler’s Cove
2026-01-01
© Alex Johnson

It was great getting out to the intertidal and seeing some of my old friends again! January isn’t the best month to find happy algae, but the rockweeds were already recruiting and growing. Here’s a baby rockweed, probably Pelvetiopsis limitata (they can be hard to ID as youngsters):

Olive-green ribbon-like structure with bifurcated tips emerging from wiry dark red threads
Baby rockweed, probably Pelvetiopsis limitata, in a thicket of Endocladia muricata
2026-01-01
© Allison J. Gong

And there were some lovely stands of Fucus:

Bunches of flattened dichotomously branching algae, olive-green in color, on rocks
Thalli of the rockweed Fucus distichus
2026-01-01
©️ Allison J. Gong

Note that the tips of the Fucus branches are flattened. These are young thalli. In the summer, mature thalli will have swollen tips full of gametes. Fucus, and the rockweeds in general, have what we call an “animal-like” life cycle instead of the alternation of generations that is more typical of seaweeds. And we won’t even get into the complexity of the alternation of three generations in some of the reds! So yes, Fucus thalli come in male and female forms that produce sperm and eggs, respectively. Sounds familiar, doesn’t it?

We saw several ochre stars, none of which were ochre in color. And now that I think about it, I see many more P. ochraceus that are purple, red, or orange than are ochre.

Dark purple star-shaped animal attached to a rock
Ochre star (Pisaster ochraceus)
2026-01-01
© Allison J. Gong
Bright orange star-shaped animal stuck to a rock
Ochre star (Pisaster ochraceus)
2026-01-01
© Allison J. Gong

And lest we forget, Sea Star Wasting Syndrome (SSWS) hasn’t been banished from the world. I suspect it will always be around but won’t always be as prominent as it was 10 years ago. Yesterday we saw two disembodied arms of a purple Pisaster ochraceus. The rest of the body was nowhere to be found, and I guess this star dismembered itself a couple of days ago.

Two approximately triangular structures on a sandy background with two large rocks and a snail shell
Disembodied arms of Pisaster ochraceus in a tidepool
2026-01-01
© Allison J. Gong

On a much more pleasant topic, I noticed a pattern of different organisms lined up in rows.

Row 1: Limpet scars. These ovoid blotches are the scars made by a limpet, Discurria (formerly Lottia) insessa. The limpet lives on the stipe of feather boa kelp (Egregia menziesii), shown below. It eats the algal film that accumulates on the kelp but eventually ends up chewing through the stipe, which then breaks. They literally eat themselves out of house and home, poor guys.

Long brown strap running horizontally across the image. There are eight golden ovals along the length of the strap.
Limpet scars on stipe of Egregia menziesii
2026-01-01
© Allison J. Gong

Row 2: Anemones. Many intertidal animals (and algae, for that matter) settle preferentially in cracks and crevices. These are the places that hold water the longest at low tide, giving the organisms a slight bit of protection against desiccation. For the same reason many organisms prefer to settle on vertical rather than horizontal surfaces. I found this group of anemones in an almost-straight line in a shallow indentation in the rock.

Five roughly circular objects arranged approximately vertically against a pink background
Row of anemones (Anthopleura spp.)
2026-01-01
© Allison J. Gong

Row 3: Anemones. In geometry, two points define a line. So I can claim that these two anemones make a row! You may have to look carefully to see the second anemone.

Circular object with white protruding tentacles radiating from center. To the right, a similar object with transparent tentacles.
Moonglow anemones (Anthopleura artemisia)
2026-01-01
© Allison J. Gong

These are the same species. Anthopleura artemisia is highly variable, more so than the other species in the genus. The tentacles can be a solid opaque color, as in the animal on the left, or transparent/translucent with or without opaque patches, as in the anemone on the right. They tend to live in sandy areas and often have sand covering the oral disc. If disturbed they will retract into the sand and disappear.

Beach landscape. Large boulders covered with brown/reddish algae or green plant growth, on sandy bottom. Gray cloudy sky above greenish water.
Scenery at Whaler’s Cove
2026-01-01
© Allison J. Gong

All in all it was a fantastic re-entry into the rocky intertidal. My body remembered how to move around, my balance was not entirely shot to hell, and my knee did fine. I was able to forget about it and just use it like a normal person would. When I started physical therapy I told the therapists that one of the things I need to be able to do was work in the rocky intertidal. They were skeptical at first, because they envisioned me jumping from slippery rock to slippery rock. I had to explain that I’m very safety conscious in the field and know all the tricks of an old-timer: Keep your body low (so you have less distance to fall) and keep three of the five points of contact (two hands, two feet, and one butt) with the rock at all times.

I’m calling this a major milestone achieved, even if I still have a long way to go. Yippee!

Five weeks

Posted on by Allison J. Gong

On Tuesday 8 July 2025 I had a total joint replacement of my right knee. Over the past year and a half or so the osteoarthritis had gotten really bad, to the point that I couldn’t walk without pain. Much less actually do anything active, like hiking or tidepooling or even carrying a camera around to take pictures. I hobbled my way through winter and spring this year and finally got a surgery date, hopefully early enough in the summer to allow some degree of recovery before the fall school term begins.

One of the folks on the surgical team, who had been shepherding me through all of the more conservative treatments—cortisone shot, hyaluronate injections—told me that the recovery schedule for a total knee replacement (TKR) goes something like this:

  • For the first four weeks I wouldn’t want to talk to anybody and would wonder why I let “them” talk me into this in the first place
  • For the next several weeks I’d be willing to talk to people and might even say “Hi” to the medical folks
  • After about six months I’d smile at the medical folks and will have regained much of my lost mobility
  • After a year I’d want to take them all out for a drink

I am at Week 5. Last week I had my 4-week post-op appointment. The nurse practitioner had me do another set of X-rays, to make sure that the implant was still correctly positioned, and checked on my incision. The X-rays tell the story and reinforce that the surgery was indeed necessary.

Mirror image X-ray views of my right knee, before and after TKR

The opaque white in the “After” image is the titanium implant, secured into my femur and tibia. The polymer cushion that replaces the worn-to-nonexistent cartilage doesn’t show up in X-rays. I had moderate osteoarthritis in all three compartments of the knee: lateral, medial, and patellar. Osteoarthritis only ever gets worse, and the conservative treatments can alleviate symptoms but don’t fix the underlying problem. Surgery was definitely needed. While he was in there replacing parts of my femur and tibia, the surgeon also completely reshaped my patella, shaving off the bone spurs and forming a smoother surface that will glide correctly between the femur and tibia. No more Rice Krispies in that knee!

Progress, right?

Afternoon mystery

Posted on by Allison J. Gong

For the past week and a half or so, every afternoon between about 14:00 and 14:30 there has been an outbreak of coyote noise in the canyon behind my house. It starts up, goes furiously for about 5 minutes, and then abruptly stops. I’m rehabbing a new knee joint and am not really mobile now, but have hobbled out to the deck with binoculars to see if I could find the coyotes. The first time I heard all the noise I worried that the coyotes had gotten into a fight with someone’s pet dog. But when it kept happening every day at the same time, I decided it must be part of the coyotes’ afternoon routine.

We heard it again today, and both went out to look. While all the yipping was going on I looked for any telltale movement in the bushes—nada. But after they had quieted down, I was looking at a grassy slope where we’ve seen all kinds of animals hanging out. And a coyote wandered out! And she had three pups following her! I took a bunch of pictures, none of which were anything to share. I did also catch about 30 seconds of video:

Mystery solved! Nice to know the next generation of California’s most successful mesocarnivore is growing up. There is a ton of food in these canyons, so there’s a good chance that this trio of pups will all survive.

What to do in Vegas when you don’t “do” Vegas

Posted on by Allison J. Gong

Twice now in the past six months I’ve gone to Las Vegas for a concert. Trust me, I’m just about the last person you’d expect to spend any time in Vegas—I have zero interest in gambling or shopping, and the nonstop lights and noise of the Strip really get on my nerves. So since we had some time to kill before the shows, we ventured out of the city to explore the desert.

One of the places we visited both times was Valley of Fire State Park, Nevada’s first state park, established in 1935. Located to the northeast of Vegas, Valley of Fire is about as un-Vegas as you can get. It’s only about an hour out of the city, and is a welcome change from the sensory overstimulation of the Strip. It would be brutally hot there in the summer, but in the fall and late winter was lovely. Even though it will never be one of my favorite habitats, I find the desert fascinating. The limited color palette has my photographer’s eye looking for nuances in color value and texture in the landscape. And some of the blue skies are amazing.

On the way to Valley of Fire this time we drove through the Lake Mead National Recreation Area. One of the interesting places we passed was Rogers Spring, which is a naturally occurring oasis. It runs continually throughout the year, although the National Park Service website says that the ultimate source of the water is uncertain.

Landscape with rocky hill in background, two palm trees and a small pond in midground, and green bushes in foreground
Rogers Spring, Lake Mead Nat’l Recreation Area, NV
©️ Allison J. Gong
2025-02-07

The sign that is mostly obscured by foliage tells people that they can protect the ecology of this rare desert oasis by not releasing their pet fish/reptiles/amphibians into the spring. Clearly the warning comes too late, as I saw many “liberated” pet fish—guppies, gouramis, and goldfish—swimming in the spring. Perhaps other springs are farther from the road and not as easily accessible as this one, and perhaps those are less affected by human stupidity.

The Valley of Fire takes its name from the iron-rich rocks that dominate the landscape. The geology of the place is amazing! We didn’t have time to go fossil-hunting or do much hiking, but even from the road the vistas were spectacular.

Landscape with white clouds in bright blue sky, rounded mountains and hills in red
Valley of Fire State Park, NV
© Allison J. Gong
2025-02-07
Landscape with blue sky and white clouds, mountains in the distance, red rocky ground in foreground
Valley of Fire State Park, NV
© Allison J. Gong
2025-02-07

Up close, we could see undulating patterns in the rock formations.

Rock formation at Valley of Fire State Park, NV
© Allison J. Gong
2025-02-07

But the one thing I really wanted to see was one of the petroglyph formations in the park. The oldest petroglyphs in Valley of Fire date back to about 2000 BCE. There are two easily accessible petroglyph formations, and we visited the one nearest the visitor center in an area called Mouse’s Tank Trail.

Petroglyphs at Valley of Fire State Park, NV
© Allison J. Gong
2025-02-07

and

Petroglyphs at Valley of Fire State Park, NV
© Allison J. Gong
2025-02-07

These particular petroglyphs are right along the trail, which is why I don’t think I’m drawing unwanted attention to them. Anybody can walk right up them, and some people have unfortunately decided to leave their mark. Obviously, that smiley face on the far left isn’t a petroglyph. I was actually surprised that the petroglyphs were as un-messed-with as they appeared to be. I’m neither an anthropologist nor an historian, but I do wonder what these early artists were trying to communicate. Some of the images are clearly people, and with some imagination I can see animals in others. An anthropologist named Eric Pacl wrote a thesis about the Valley of Fire petroglyphs for their M.A. degree in Archeology from UNLV in 2012. I defer to their expertise and interpretation of the petroglyphs.

So if you find yourself in Vegas and don’t want to the whole Vegas thing, head out of town and check out Valley of Fire State Park. You won’t regret it!

Spying on the hunter

Posted on by Allison J. Gong

This afternoon I was hanging some laundry to dry on the back deck, when something reddish caught my eye. I grabbed the binoculars, peered down into the bushes, and saw a pair of ears emerging from behind a bush. Soon a very handsome coyote came out to bask in the sun. Just in case it did anything interesting I fetched the camera, which was fortunately already wearing the 400mm lens, and settled down to watch for a while.

After a few more moments enjoying the sun, the coyote got up and went on alert. It had clearly heard something. A late lunch, maybe?

Reddish-brown doglike animal with large ears standing on hillside and looking off to its right
Coyote (Canis latrans)
2025-01-15
© Allison J. Gong

Yes indeed, the hunt was on!

Reddish-brown doglike animal facing to the right with its head at ground level behind some tall grass
Coyote (Canis latrans)
2025-01-15
© Allison J. Gong

It didn’t take long for the hunter to make its catch.

Reddish-brown doglike animal with large ears turning to face left and carrying a gray object in its mouth
Coyote (Canis latrans) carrying a rodent in its mouth
2025-01-15
© Allison J. Gong
Reddish-brown doglike animal with large ears facing the left and carrying a gray object in its mouth
Coyote (Canis latrans) carrying a rodent in its mouth
2025-01-15
© Allison J. Gong

But in the manner of a cat, the coyote dropped the rodent and played with it for a while.

Once the rodent (which I think was a rat of some kind) was captured, it took more chomping than I had anticipated for the coyote to actually eat it. I kept thinking, “Okay, it must be done now,” and the coyote would turn its head to show me the rodent sticking out of the side of its mouth.

The entire event, from when the coyote first heard the rustling of the rodent to when it stood up and walked away, lasted about five minutes. Shortly after finishing its meal the coyote stood up, threw a glance down the hill, and disappeared into the bushes.

Reddish-brown doglike animal with large ears standing on hillside and looking off to its right
Coyote (Canis latrans)
2025-01-15
© Allison J. Gong

We often hear coyotes yipping at night, which inevitably riles up all the neighborhood dogs, and occasionally we capture one on the critter cam. It’s not unusual to see coyotes in the daylight, but this is the first time I’ve gotten to see one hunting and making a kill. This coyote looked very healthy. And this is why we keep the cats indoors!

Collateral damage

Posted on by Allison J. Gong

My home town of Santa Cruz made national news the other day, 23 December 2024, when a series of massive swells caused part of the Municipal Wharf to collapse into the ocean. People in the restaurants and other businesses had to evacuate immediately, and three people were dropped into the water of Monterey Bay (they were all rescued safely and no human lives were lost). The bathroom building fell into the water and washed up on the beach at the mouth of the San Lorenzo River. Almost immediately, memes appeared, advertising a 2-bathroom unit with both river and ocean views, renting for $6000/month. Given the exorbitant rents here, you could argue that maybe this is a pretty good deal.

That afternoon, the same swell tore through the Santa Cruz Small Craft Harbor and replicated the damage done by the Fukushima tsunami in March 2011. The damaged docks had been replaced in 2014, but this recent damage ripped them up again. Boats and docks were thrown around and crashed into each other. An unknown amount of diesel fuel and gasoline were also “liberated” into the water.

My friend Murray has a little boat, Scherzo, that lives in the upper harbor on G dock. On the day of the worst swell, Murray had gone down to see how Scherzo was faring. At that point she had taken at least some cosmetic damage to her paint but didn’t seem to be taking on any water except rain water. The harbor patrol had closed all of the docks so he couldn’t get close enough to see if there were worse injuries. At one point another boat had come down the channel and gotten wedged under Scherzo so she was floating on top of it. Somebody rescued Scherzo and tied her up at a spot just under the ramp from her usual berth. Yesterday, Christmas Day, Murray called us to say that he was down at the boat and asked if Alex (my husband) could help him get her out of the water, as more big swells were forecast. I’m not very useful when it comes to boats, but I went along to watch things from above and hold lines and such.

Before they could take Scherzo out of the water, they had to make sure she was seaworthy enough to be driven down to the boat ramp at the lower harbor.

Dock with two large boats tied up on one side and one small boat tied up on the other side. One person in the small boat. One person crouching on the dock next to the small boat
Murray and Alex give Scherzo a check-up
2024-12-25
© Allison J. Gong

Behind Murray, who is wearing the pink cap, you can see damage to the finger dock. And notice that the big boats aren’t sitting straight in their slips. Scherzo‘s usual spot is on the other side of the ramp; she got pushed under the ramp and a kind soul tied her up here.

This is the capsized boat that had gotten wedged under Scherzo. It was now stuck under the ramp, just in front of Scherzo‘s spot.

Capsized boat wedged under a pedestrian bridge
Capsized boat under ramp
2024-12-25
© Allison J. Gong

Scherzo‘s engine started right up, and the boat itself having been deemed safe to drive by Alex the Engineer, Murray took her down the harbor slowly. Alex and I met him at the boat ramp.

While we were waiting, we noticed that some of the pilings from the busted-up Wharf, which is more correctly a pier rather than a wharf, had been hauled out of the water and set in the parking lot.

Wharf pilings in the harbor parking lot
2024-12-25
© Allison J. Gong

Knowing that the biota on the pilings would be very similar to the critters I see in the rocky intertidal, I had to investigate. And it was very sad. Most of the animals had died waiting for a high tide that wouldn’t return. Some of the barnacles were still alive, albeit just barely so.

Log lying on pavement, covered with small pink blobs and large brown objects also covered with small pink blobs.
Large barnacles (Balanus nubilus) and pink corallimorpharians (Corynactis californica)
2024-12-25
© Allison J. Gong

Here’s a close-up shot of one of the big barnacles encrusted with other animals:

Beige pyramid-shaped structure with pink blobs on the lower surfaces
Large barnacle (Balanus nubilus) and pink corallimorpharians (Corynactis californica)
2024-12-25
© Allison J. Gong

There were many empty worm tubes, former homes of the beautiful Eudistylia polymorpha. I saw one dead worm that had fallen out of its tube:

De-tubed feather duster worm, Eudistylia polymorpha
2024-12-25
© Allison J. Gong

One of the rocky intertidal denizens, the pink barnacle Tetraclita rubescens, was there, too:

Pink barnacle (Tetraclita rubescens) with smaller barnacles (Balanus glandula) and mussel byssal threads
2024-12-25
© Allison J. Gong

To get a feel for how big Balanus nubilus and Tetraclita rubescens are, my left index fingernail measures exactly 10 mm across. That B. nubilus is a big sucker!

Large volcano-shaped structure with two smaller pink volcano-shaped structures on the side. Finger for size reference
Balanus nubilus and Tetraclita rubescens
2024-12-25
© Allison J. Gong

Balanus nubilus is a strictly subtidal species that I never see in the intertidal. Tetraclita rubescens occurs in both the intertidal and the subtidal; some of these subtidal specimens were larger than the ones I see in the intertidal. Most sessile marine invertebrates can feed only when they are covered by water, which means that the ones living in the intertidal don’t feed at low tide. Thus the subtidal T. rubescens can get larger than their intertidal conspecifics, simply because they can feed 24/7. We see the same pattern with mussels in the intertidal: those higher up in the mussels’ range are smaller than the ones in the lower part of the range.

Some of the barnacles were still alive. They can close up their shells and wait out a low tide. But sitting out of the water for longer than a day was more than even they could withstand.

Other old friends were there, including many sea anemones. This is the sunburst anemone, Anthopleura sola, looking the way it does when I see it in the intertidal at low tide.

Cylindrical animal hanging down from vertical surface
Sunburst anemone (Anthopleura sola)
2024-12-25
© Allison J. Gong

Other anemones had been caught in the act of dividing. These would be the cloning anemones, Anthopleura elegantissima.


2024-12-25
© Allison J. Gong

2024-12-25
© Allison J. Gong

Probably the saddest thing was a desiccated red octopus on the pavement. It had probably plopped out of a nook and tried to make its way back to water. Poor little thing.

Grayish-brown lump with suckered arms
Red octopus (Octopus rubescens)
2024-12-25
© Allison J. Gong

The organisms on these pilings were caught in their final moments of life, just as the citizens of Pompeii and Herculaneum were when Mt. Vesuvius erupted in 79 AD. Some of them had tried to escape (the octopus) and some were not quite dead yet (the barnacles), but the inevitable is well, inevitable. At some point the pilings will be removed to the landfill. The same thing happened when the harbor docks were replaced in 2014. I happened to be there with a class and we saw all of the old docks piled up in the parking lot, with all of the attached biota slowly drying up in the sun.

So while there will be reports in the coming days about how many millions of dollars it will take to rebuild the harbor (again) and the pier, let’s not forget that there were other losses that cannot be assigned a dollar value. There is also a potentially major ecological impact of new (again) harbor docks. When the old docks were removed in 2014, they had been covered with a decades-old fouling community. The new docks were pristine new habitat for recruits, and shortly after they were put in I noticed an invasive brown alga, Undaria pinnatifida, which I hadn’t seen before. Undaria is a western North Pacific edible seaweed that is known culinarily as wakame. In recent years it has become one of the most abundant macroalgae in the lower areas of the harbor. The docks that were destroyed this week had been in place for only 10 years or so, and it will be interesting to see how primary succession occurs when new docks are installed. Hmm, that sounds like something I can have my Ecology students document and monitor!

(not so?) Big Day

Posted on by Allison J. Gong

Yesterday, 12 October 2024, was October Big Day, an annual community science event hosted by Cornell Lab of Ornithology and their eBird app. Each Big Day is a snapshot of bird diversity, and the October date is timed to catch migratory birds. The goal is to record how many of each species you observe, either by sight or hearing, at some location for some period of time. Due to circumstances beyond my control I was constrained near home, but I managed to get three sets of observations in.

Back deck at home 15:30-16:00

SPECIESNUMBER
Anna’s hummingbird15-20
Lesser goldfinch4
Chestnut-backed chickadee2
House finch2
Northern mockingbird1
Spotted towhee1
Scrub jay2
California quail1
California thrasher1
Bewick’s wren1
Song sparrow2
Golden-crowned sparrow2
Red-tailed hawk1
California towhee1
Wrentit1
Bushtit1 (really? only the 1?)
Hermit thrush1

TOTAL: 17 species

Long Marine Lab 16:43-17:30

Distance traveled: 0.61 miles

SPECIESNUMBER
Mallard2
Rock dove (i.e., pigeon)14
Western gull2 for sure, plus probably many others
Brandt’s cormorant33
Brown pelican80-ish
Black phoebe5
American crow3
Bewick’s wren1
House finch2
Golden-crowned sparrow1
California towhee1

TOTAL: 11 species

Natural Bridges State Park 17:30-18:20

Distance traveled: 1 mile

SPECIESNUMBER
Anna’s hummingbird4
Red-shouldered hawk1
Northern flicker1
Black phoebe1
American crow3
Chestnut-backed chickadee4
Oak titmouse1
Pygmy nuthatch1
Bewick’s wren1
Golden-crowned sparrow2
California towhee2
Song sparrow3
Spotted towhee2
Townsend’s warbler1

TOTAL: 14 species

If I counted correctly and didn’t double-count anybody, that makes for 30 species observed in about 3 hours. I’m not really surprised that I saw the most diversity at home, compared to the marine lab and Natural Bridges. Our back “yard” is literally a canyon with lots of habitat diversity, although not as much native vegetation as I would like. It’s a bit of mostly-wild nature in the city. We also know that we have larger wildlife—deer, foxes, skunks, raccoons, and the occasional mountain lion—prowling around down there. I’m very lucky to live here.

The most interesting thing to come out of these observations is the question “Was there really only one bushtit?” Because you always see them in a group of 12-30, forming a twittering mass of tiny objects flitting around in the bushes. But I kept looking, and saw only the one.

People who consider themselves good birders would scoff at numbers like mine, and some would wonder why I would even bother counting birds I see at home. But I’m not a birder. I am a birdwatcher, and there can be a big difference between the two. I literally just watch birds. I can do so for a long time, observing the same species (maybe even the same individuals) over and over again. Sometimes I count them, sometimes I draw them, and sometimes I just watch them. And it’s a delightful hobby! I don’t keep a life list, except for when I remember to enter observations into eBird, which doesn’t always happen. I don’t travel to see a rare bird that got a little lost, like that poor snowy owl that ended up in Southern California and attracted the attention of hundreds (thousands?) of birders and photographers. For the most part I’m perfectly happy spending time with “my” usual friends, watching the hummingbirds fight-fight-fight and taming a chickadee to take peanuts from my hand. We put out a couple of bird houses and keep hoping that somebody moves in to raise a family, but so far that hasn’t happened yet.

Maybe next year!

I saw the light!

Posted on by Allison J. Gong

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.

Flat body of water with mountains and clouds in background. Small boat moored at dock in lower right corner.
View from our rented house in Egmont, BC. Scherzo is the little boat moored at the dock.
© Allison J. Gong
2024-08-15

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.

Appreciating the tinies

Posted on by Allison J. Gong

Earlier this week I collected a plankton sample and settled down for a day of microscopy. For a variety of reasons it was my first foray into actual biology for the month of June, and I just wanted to feel like a marine biologist for a while.

As far as plankton samples go, there wasn’t a lot to write home about. The large centric diatoms that we had seen in the spring were much less abundant, although there was quite a bit of the pennate diatom Pseudonitzschia. Part of the reason I did the plankton tow was to have something to look at under the microscope and to practice taking photos. There are all sorts of gadgets that allow one to use a phone to take photos through the microscope, but I’ve found those to be either specific to one phone model or too fiddly and frustrating to get properly lined up. Besides, when I bought my microscope several years ago now I had the foresight to splurge for the trinocular head, which allows me to mount a real camera and leaves both eyepieces available to look through. Might as well take advantage of it!

So, I just took a bunch of photos.

First up was a chain diatom in the genus Chaetoceros. Phase contrast lighting might not have been the best option here, but oh well. Chaetoceros cells are box-shaped, with a spine protruding from each corner of the box. Aside: ‘chaeto’ means ‘hair’ or ‘bristle’ in Greek. The spines of adjacent cells sort of interlock and hold the cells together, forming the chain. Spines also provide some defense against predation.

Many species of Chaetoceros form straight chains like this.

Chain diatom Chaetoceros sp., viewed with phase contrast lighting
2024-06-24
©Allison J. Gong

But one species, Chaetoceros debilis, forms spiral chains!

Spiral chain of gold-colored boxes
Chain diatom Chaetoceros debilis, viewed with brightfield lighting
2024-06-24
©Allison J. Gong

Earlier in the spring there were a lot of Coscinodiscus diatoms in the local plankton. Those are the big button-like diatoms with the sculpted frustule. They aren’t nearly as common now, but I did see a few. And managed to get a nice shot of one:

Golden circular object

The star of the show was Thalassiothrix, another diatom in which the ends of cells cells remain connected after dividing. Instead of forming chains as Chaetoceros does, Thalassiothrix makes colonies that are either zig-zag or star-shaped. It just so happens that this organism looks especially brilliant under darkfield lighting, so I was very happy.

Diatom Thalassiothrix sp, viewed under darkfield lighting
2024-06-24
©Allison J. Gong

But take a look at this symmetry:

Fan-shaped arrangement of long golden rectangles, against a black background
Diatom Thalassiothrix sp, viewed under darkfield lighting
2024-06-24
©Allison J. Gong

Isn’t that a spectacular organism? I had a lot of fun developing and processing that image, and am happy at how well it turned out. Darkfield lighting is fun to play with!