Just wondering. No answers.

I look at a beach and I wonder. What shaped it like this? How? And how long did it take?

Sometimes there are answers. Sometimes (usually?) they include words like "maybe", "possibly", "it has been suggested".

Wind, water, ice, (moving or still). Gravity, friction, chemistry, heat, life. And time, lots of time. Or not.

These are photos from one hour on one small stretch of beach. 

At the bottom of the intertidal zone. Soft rock, shaped by waves, currents, colonized by barnacles and oysters.The tip is probably exposed at high tide. This rock is marked on the boating map, labelled "awash rock".

Glacial erratics. Oysters, barnacles, seaweeds. Quadra Island in the background. The current in this channel runs fast and strong and sometimes chaotic.

Wide stripes, running out to the water: rocks, then flat stone or sand, then rocks, then ...

Upper beach, almost flat. Water draining from pools around rocks as the tide goes out carves lines in the sand. (Land to the right here, ocean to the left.)

A bit higher up. The tide is far out, and the sand is almost dry, but water still trickles down from the land above the tidal zone, seeping through the sand.

~~~~~~~~~~~~~~~~

Miro una playa y me pregunto: ¿Qué le dió esta configuración? ¿Cómo? ¿Y cuánto tiempo fue necesario?

A veces hay respuestas. A veces —¿Casi siempre? — las respuestas incluyen palabras como "tal vez", "posiblemente", "se ha sugerido".

El viento, el agua, hielo, tranquilos o en movimiento. La gravedad, la química, la fricción, las temperaturas, la vida. Y tiempo. Mucho tiempo. O no.

estas son fotos que saqué en un tramo pequeño de playa. 

1. Donde termina la zona intermareal. Rocas suaves, esculpidas por las olas, las corrientes, y colonizadas por bálanos y ostiones. La cima probablemente sigue descubierta con la marea alta.  Esta roca está señalada en el mapa para navegantes.
2. Bloques erráticos, dejados por los glaciares.  Ostiones, bálanos, algas marinas. Al otro lado del estrecho se ve la isla Quadra. La corriente en este sitio corre rápido y fuertemente, a veces en forma caótica.
3. Franjas amplias, corriendo en dirección hacia el agua. Piedras, luego roca aplanada o arena, luego rocas, luego ... se repite.
4. En la zona superior de la playa, casi horizontal. Agua que drena desde pozas alrededor de las rocas al salir la marea dibuja lineas en la arena. (Tierra firma queda a la derecha.)
5. Esto está en la parte más alta de la zona intermareal. La marea ha dejado casi seca la arena, pero agua sigue escurriendo, bajando de la tierra firma.

Cushioned wall

Eons ago, the glaciers slid off the emerging mountain peaks that form the bulk of Vancouver Island, and crawled slowly into the sea. As they reached the water, they sped up, carving long scratches into the rocks beneath them, dropping rocks as they melted into the sea water.

Along Stories Beach in Campbell River, they left these long dikes.

All sand on the north side of the dike, mostly rocks and stones on the south.

It almost looks like a human-built wall.

The dikes at this level of the intertidal zone are usually out of water at low tide. Some, but not much, seaweed grows on them. Tiny barnacles cover large portions of the rocks. In the sand alongside, look at pockmarks in the sand; down below, you'll probably find green sea anemones.

And they're there, in great numbers, along the vertical faces of the dikes.

A section of dike wall.

Coming closer.

And zooming in.

They grow in patches, separated by areas of clean rock.  Could this be evidence of colony war?

"Colonies of clones actually war against each other." (Marine Life of the PNW)

Probably the only way to be sure would be to compare their DNA. Not on the books at the moment.

Another colony. The small white circles are acorn barnacles. The large barnacles are the gianrt acorn barnacles.

 ~~~~~~~~~~~~~

Hace milenios, los glaciares bajaron de las montañas que forman la isla de Vancouver, y se deslizaron hacia el mar. Al llegar al agua, aceleraron su marcha, haciendo grietas largas en el sustrato, abandonando rocas y piedras al descongelarse.

En la playa Stories Beach, en Campbell River, dejaron atrás estos diques.

Foto #1: En el lado norte del dique, hay arena; al lado del sur, los glaciares dejaron rocas y piedras.

#2: El lado norte del dique casi parece un viejo muro hecho por humanos.

Los diques a este nivel de la zona intramareal casi siempre quedan fuera del agua a marea baja. Unas pocas algas marinas crecen allí, y muchos balanitos. Entre la arena, si buscas en las depresiones pequeñas, encontrarás anémonas verdes.

Y en la parte baja del muro, allí están, en gran núnero.

 #3 a 5: Una parte del muro, vista de lejitos, de más cerca, y aun más cerca.

Crecen en grupo separados por areas limpias de la roca. ¿Será esto un indicio de las dichas "guerras" entre colonias?

"Las colonias compuestas de clones hasta llegan a hacer guerra contra otras." (De la enciclopedia Marine Life PNW)

Solo con una secuenciación de su ADN, se podrá saber por cierto. Por ahora, quien sabe.

#6: Otro grupo de anémonas. Los circulitos blancos son bálanos chicos, Balanus glandula; los bálanos grandes son Balanus nubilus.

Spines on the sixth leg

The tide was low. Not as low as it gets, but low enough to completely expose the Oyster Bay breakwater and a few of the smaller sections of the remains of WWII ships scuttled there 75 years ago, just after WWII. (Story here, "A bit of logging camp history", and here, "Rust in Peace".)

Around the rock breakwater, the rocks deposited in 1950 to partially replace the fleet of derelict ships, a three-quarter century of the strong currents of Georgia Strait, which separates Vancouver Island from the mainland, has built mounds of gravel on the landward side, creating a broad spit colonized by salt-loving pickleweed and silver burweed. The gravel has extended almost back to the land, enclosing the shallow lagoon. (How do the waves bring in fist-sized rocks? They do, in great heaps.)

View from the "inside"

The position of the log, floated into place, shows the usual high tide line. The protected lower sides of the rocks are coated with barnacles and tiny periwinkle snails.

On the "outside", there's only a narrow, sloping ribbon of gravel, then the wide, flat sandy beach, usually underwater. I poked around on this strip, peering into cracks and examining old rusty ship parts.

Part of a bulwark, maybe? Some of the old yellow paint still remains.

Zooming in. Barnacles, green and red algae, and rivets. And snails, but they're hiding.

And zooming in once again.

These are our common acorn barnacles, Balanas glandula. They don't like heavy wave action, but coat the protected side of rocks and the stony shores where the slope is shallow, reducing the pounding action of the waves. (Walking on one of those beaches, even watching where I put my feet, I hear the "crunch, crunch" of tiny barnacle shells, making crab feed. Sorry, guys! If I could fly, I would.)

They grow densely together; once they've settled in, they won't be moving for the rest of their lives (up to 30 years, I've heard, as long as I don't step on them.) So they have to settle within reach of a mate.

The barnacles are sequential hermaphrodites. That is, they have both male and female organs, and in any one mating event, one acts as female, the other as male. The one acting as a male reaches out a penis up to 8 times his body size to reach a neighbour, who acts as a female for this encounter.

Poor photo, 2010. Barnacle with extended penis, looking for a mate.

On the protected side of a nearby rock, I found bigger barnacles:

Giant acorn barnacles surrounded by the smaller species.

One giant, with small acorn, red algae, and periwinkle snails.

The giant acorn barnacles, Balanus nubilus, are easily recognized by size alone. They may be the largest acorn barnacles worldwide, and can grow up to 15 centimetres across. These are smaller; about 5 cm. The little "commons" can grow up to a maximum of half that. But even in a juvenile, the giants are recognizable by the beak-shaped inner shells, the operculum. Underwater, and feeding, they expose a brilliantly coloured inner body, red, orange, or purple. (I've seen mostly reddish-purple ones.)

Of the small acorn barnacles, there are several similar species. Most of ours are B. glandula but I've also seen the thatched barnacle, B. cariosus, and there is one that settles on crab shells, B. hesperius and several others. All very similar, all extremely variable, depending on water currents, erosion, and the effects of crowding; hard to identify. E-FaunaBC describes the problem:

However, it is not safe to rely alone on the sculpture of the cover-plates for identification as there are species with plates that look nearly the same. Therefore, several other characters must be taken into consideration. The number of spines on the middle segment of the sixth leg; the shape of the mouth parts; and the structure of the base of the shell.

In the absence of barnacles waving those sixth legs at me, I'll just be glad that the name "acorn barnacle" applies to all of them.

~~~~~~~~~~~~~

La marea estaba baja. No tan baja como puede llegar a ser, pero suficiente como para dejar el rompeolas de Oyster Bay completamente fuera del agua, además de algunas partes de barcos sumergidos allí hace 75 años, después de la Segunda Guerra Mundial. (La historia, la puedes encontrar aquí, "A bit of logging camp history", y aquí, "Rust in Peace".

Alrededor del rompeolas, rocas depositadas en este sitio en 1950, para reemplazar (en parte) la flota de barcos en ruinas, tres cuartos de siglo de corrientes de agua del Estrecho de Georgia, que corre entre la isla de Vancouver y el continente, ha construido montones de grava en el lado protegido, creando una lengua de tierra donde crecen Salicornia depressa y Ambrosia chamissonis, plantas halófitas. La grava casi llega a tierra firma otra vez, encerrando una lagunita poco honda. (¿Cómo es que las olas llegan a traer piedras del tamaño de mi puño? No sé, pero sí lo logran)

Foto #1: La vista hacia el mar desde el lado interior del rompeolas. El tronco sobre las rocas llegó flotando y marca el nivel normal de la marea alta. Los lados protegidos de las rocas llevan colonias de bálanos y de caracolitos marinos.

En el lado del rompeolas expuesto al mar hay solo un listoncito de grava inclinada, y luego la playa extendida, arenosa, plana, casi siempre sumergida. Este tramo de grava, con sus fierros viejos y rocas agrietadas estaba fuera del agua.

Fotos # 2 a 4: Un pedazo de barco viejo. Parte del costado, tal vez. Acercándonos, vemos bálanos, algas verdes y rojas, los caracolitos, casi escondidos, y remaches.

Estos son nuestros bálanos comunes, Balanus glandula. No les gusta la acción de olas fuertes, y colonizan los lados protegidos de las rocas, y las piedras de playas poco inclinadas, donde las olas entran suavemente. (Caminando en una de esas playas, aunque tengo cuidado donde pongo los pies, oigo el crujir de bálanos apachurrados, convertidos ahora en comida para cangrejos. ¡Lo siento, criaturitas! Si pudiera volar, lo haría.)

Crecen en colonias densas; una vez que se hayan fijado en la roca, no van a estar libres de ir a buscar pareja, y la necesitan tener cerca. Vivirán en este sitio hasta, según me dicen, hasta 30 años.

Los bálanos son hermafroditos secuenciales, es decir, tienen los órganos de ambos sexos y pueden actuar como hembra o como macho en un apareamiento dado. El que actúa como macho extiende su pene a una distancia que llega a ser hasta 8 veces su propio diámetro para buscar su pareja, quien en este momento actúa como hembra.

Foto #5: Una foto un poco borrosa, mostrando un bálano con el pene extendido. 2010

En el lado de una roca encontré bálanos más grandes:

Fotos #6 y 7: Bálanos gigantes, Balanus nubilus rodeados de bálanos comunes.

Estos bálanos gigantes se conocen facilmente por su tamaño; pueden ser los bálanos más grandes de todo el mundo y pueden crecer hasta 15 cm. de diámetro. Estos, en la foto, son juveniles, midiendo como unos 5 cm. Los bálanos comunes que los rodean pueden llegar a lo máximo, a la mitad de esto. Pero aun en un gigante joven, todavía chico, se puede reconocer la especie por el operculo, las placas interiores, que toman la forma de un pico de ave. Abiertos, bajo agua, se ven los colores fuertes del animal escondido; rojo, anaranjado, violeta.

Entre los bálanos pequeños, hay varias especies muy similares, todas muy variables según el sitio, sea con olas más o menos fuertes, sea con menos espacio, o donde haya erosión fuerte. En E-FaunaBC se describe el problema: 

Sin embargo, no se puede con seguridad depender solamente en la forma de las placas cobertores para su identificación ya que hay especies con placas que se ven casi idénticas. Por lo tanto, hay que tomar en cuenta otras características. El número de espinas en el segmento central de la pata sexta; la forma de las partes bucales; la estructura de la base de la concha.

Yo, no viendo balanitos enseñandome sus patas sextas, me conformo con que el mismo nombre, "bálanos bellota" se aplica a todos. Hasta a los gigantes; Bálanos bellota gigantes.

Open mouth, evert foot

 It's been rainy and windy and cold all day. A good day to stay inside and watch barnacles.

Acorn barnacle fishing.

Barnacles stand on their heads inside their fortified castles, fanning their feathery feet (cirri) in the water, catching tiny fragments of food. There are 6 pairs of cirri; the first three are larger, and often the only ones seen.

The cirri also include gills, so the barnacle is breathing as well as fishing while he fans his legs through the water.

A quick sweep.

To capture these two barnacles with the cirri extended, I took 80 photos. A mouth opens, (not in the barnacle I was focussing on, usually) a hint of cirri appears. Next, maybe the mouth closes again. Maybe the cirri sweep out, vibrate for a moment, then fold back in, all in a short second. Maybe they sweep out, fold in almost too fast for the eye to capture them. They don't stick to any rhythm, and each barnacle has its own personal style.

They're faster than my shutter finger. 

In the photo above, you can also see the tentacles of a tiny anemone. At least these stay open most of the time, although they sway in the current.

The stone these barnacles sit on, with three anemones and a long-legged isopod.

~~~~~~~~~~~~~~~~~~~~

Llovió todo el dia; hubo un viento fuerte y frio. Un buen dia para quedarme en casa observando los bálanos.

Fotos: bálanos buscando su comida.

Los bálanos se paran de cabeza dentro de sus castillos fortificados, extendiendo sus piernas emplumadas (llamadas cirri) para pezcar pequeños fragmentos de comida. Hay 6 pares de estos cirri; los primeros son más grandes, y a veces son los únicos que se pueden ver.

Los cirri también contienen las branquias, así que mientras buscan su comida, también están respirando.

Para sacar estas dos fotos de bálanos en el acto de pescar, tuve que sacar 80 fotos. Una boca se abre, (pero no la del bálano que tenía enfocado, claro); se asoman unos cirri. En seguida, puede ser que la boca se vuelve a cerrar. O tal vez se extienden los cirri, vibrando por medio segundo, y se retraen. O pueden salir y desaparecer tan rapidamente que apenas los ojos llegan a verlos. Y no llevan ningún ritmo, y cada balanito tiene su propio estilo, muy personal.

Son más rápidos que mi dedo en el obturador.

En la segunda foto se ven también los tentáculos de una anémona miniatura. Estas por lo menos se mantienen abiertas por mucho tiempo, agitándose con los corrientes del agua.

La tercera foto muestra la piedra donde están fijos los bálanos, con tres anémonas y un bichito de patas largas, probablemente un isópodo.

Bane of barnacles

Walking on the rocks below the high tide level, I am aware that I'm stepping on hundreds, thousands of barnacles. Tiny critters, glued in place, unable to scuttle into shelter like the crabs do, they hunker down and endure my footsteps. And yet I don't leave behind a trail of flattened barnacle meat.

Because they're well armoured. Each barnacle lives in a castle made of 6 solid calcite plates, cemented to a base plate, and for a door, there are another 4 movable plates. Packed together, up to 70,000 per square metre, they make a hard cover on the rocks, almost as hard as the rocks themselves.

Two species of barnacles; the tiny acorn barnacles, and the large, ridged thatched acorn.

But if I'm not a danger to the barnacles, they still have their enemies. Mainly snails.

Wrinkled rocksnail, Nucella lamellosa

These snails are probably the most common in our intertidal zone; they're extremely variable in shape and colour, and grow up to about 5 inches long. And they eat barnacles, scraping holes through those castle walls with their file-like radulas.

Another wrinkled dogwinkle. This one has "frills", which may serve as a protection against crabs.

A dire whelk, lirabuccinum dirum. Wearing a family of limpets.

The dire whelk is a predator and scavenger. It eats any injured prey, and barnacles are high on its list of favourites, although they have to wait until they open; these snails don't drill through the walls.

And a leafy hornmout snail, Ceratostoma foliatum.

The leafy hornmouth has three "wings" the length of its thick shell, protecting it from hungry crabs. Another barnacle eater.

It drills through their protective shell with its radula. After drilling through the shell Ceratostoma foliatum injects digestive enzymes into the prey's body cavity and sucks out the dissolved tissue.(WallaWalla)

Top side of the leafy hornmouth.

Poor barnacles!

~~~~~~~~~~~~~~~~~~~~~~~~

Caminando en las piedras en la zona intramareal me doy cuenta que estoy pisando miles de bálanos. Tan chicos, fijados al substrato, sin la capacidad de correr a esconderse como lo hacen los cangrejos, lo único que hacen es encerrarse y aguantar mi peso. Y sin embargo, no dejo atrás un rastro de carne aplanada de bálano.

Pues tienen su protección. Cada animalito vive en un castillo formado de 6 placas sólidas de calcita (carbonato de calcio), bien cimentados sobre su base, y con un portón hecho de otras 4 placas. Viviendo juntos, estrechamente apretados, llegando a alcanzar hasta 70,000 por metro cuadrado, forman una capa dura en la roca, casi tan dura como la roca misma.

Primera foto: dos especies de bálanos; Balanus glandula y el más grande Semibalanus cariosus.

Pero si yo, con todo y patas pesadas, no soy gran peligro para los bálanos, siguen teniendo enemigos, entre ellos, los caracoles marinos.

Segunda y tercera fotos: Nucella lamellosa, un buccino común en estas playas. Vienen en una gran variedad de formas y colores, y crecen hasta unos 12,5 cm. de largo. Y comen bálanos, taladrando la concha con su rádula hasta penetrar a la carne en el interior.

Cuarta foto; un buccino "terrible", Lirabuccinum dirum, decorado con una familia de lapas.

Este caracol es carnívoro, comiendo presa viva, dañada o muerta. Le gustan los bálanos, aunque tiene que esperar a que se abran, porque no usa la rádula para romperse camino.

Quinta foto: Ceratostoma foliatum, el caracol de "boca cornuda, con hojas". Este caracol trae tres "alas" pesadas a lo largo de la concha, lo que le protege de ataques de cangrejos. Y come bálanos.

"Taladra sus conchas protegedoras con la rádula. Después de taladrar la concha, Ceratostoma foliatum inyecta enzimas digestivas en la cavidad del cuerpo de la presa y luego succiona el tejido disuelto." (WallaWalla U)

¡Los pobres balanitos!

Staying put

About those pilings:

All that remains

Once upon a time, long ago, there used to be a small dock here, at the far end of the beach south of Oyster Bay. All that is left is the double line of pilings, covered with mussels and barnacles.

Mostly mussels, Mytilus trossulus

And little acorn barnacles.

Peering into tide pools, or flipping rocks, or looking at masses of animals, like these, I take photos. Not very good photos, mostly; what there is to see is too muddled for the camera to focus, and I can't focus manually, wobbling on the mostly precarious footing. But at home, I zoom in and inspect the photos carefully; there's usually something I could not see without the help of the camera. They're not usually clear even then; I see the striped antenna of a hairy hermit, the angle of the knee of a kelp crab, a smiley face on the back of a shore crab, maybe a glimpse of the curved back of an amphipod or a flash of the iridescent body of a worm. There may be baby sea urchins, or a few tentacles of an anemone. Snails and limpets, usually.

In these mussel photos, and several more, there are barnacles. Not a hint of anything leggy. Barnacles and mussels, mussels and barnacles. Four or five small snails, on the outer edges of the clump.

 The thing is, mussels are dangerous to anything that wants to move about. Barnacles are sessile; once they're settled, they're there for life. But if you need to move to find food, better stay away from mussels. They tie themselves down to the substrate with incredibly tough threads, called byssal threads; I try to separate a few tied together by pulling them apart; can't be done. I would need a knife. One alone, I can handle with a good pull. And they tie down anything they touch.

I have put a few mussels in my aquarium; they're good filters. But I have to keep an eye on them; they capture wandering snails, tie them down, and let them die of starvation.

The mussels that have died and are gaping open have probably been eaten by swimming things.

Another couple of photos: the pilings are hollow, the inner wood eaten away. It was dark inside, and I couldn't see anything, but I poked the camera in and let the flash expose whatever was in there. I wish I had taken more: here are two that I took before I decided it was useless.

Most of the mussels and barnacles are on the outside. Inside, a red feather-duster tubeworm, a plumose anemone, sea lettuce.

A better look at the anemone.

~~~~~~~~~~~

Esos pilotes ...

Hace tiempo, había un muelle pequeño aquí al final de la playa al sur de Oyster Bay. Ahora no queda más que los pilotes, cubiertos de mejillones y bálanos.

En la playa, investigando pozas de marea, volteando piedras, o examinando masas de animales como estos, saco fotos. Muchas fotos, no muy buenas, ya que la cámara no puede decidir a donde enfocar, y no puedo usar enfoque a mano, puesto que estoy tambaleando sobre suelos resbalosos o temblantes. Pero en casa, examino esas fotos cuidadosamente, porque siempre hay algo que no pude ver a simple vista. La antena de un cangrejo ermitaño, Pagurus hirsutiusculus, el ángulo de la rodilla de un cangrejo "kelp", la cara sonriente marcada en el dorso de un cangrejo común, tal vez una fracción del dorso redondeado de un anfípodo, o los colores iridiscente de un gusano poliqueto. Habrá erizos de mar infantiles, los tentáculos de una anémona. Caracoles marinos y lapas, casi siempre.

En estas fotos de mejillones, y varias más que saqué en los pilotes, hay bálanos. Y ni un atisbo de nada con patas. Mejillones y bálanos, bálanos y mejillones. Unos cuatro o cinco conchas por las orillas.

La cosa es que los mejillones son peligrosos. Por lo menos, si algo quiere moverse. Los bálanos son sésiles; se adhieren a una superficie y nunca más se mueven. Pero si eres algo que tienes que andar de aquí para allá buscando comida, hay que evitar los mejillones. Ellos extienden sus lazos, los dichos hilos "byssus", muy fuertes, y amarran todo lo que tocan. He tratado de separar varios mejillones amarrados juntos; no pude. Necesitaba un cuchillo. Un mejillón en una piedra, si, con trabajos. Son increíblemente fuertes.

He traído a casa unos para añadirlos al acuario. Son animales filtrantes muy buenos. Pero los tengo que vigilar; atrapan y amarran conchas marinas, y las detienen hasta que se mueren de hambre.

El centro de los pilotes están vacíos. La madera interior se ha disuelto. Está muy oscuro ahí dentro, pero metí la cámara, usando el 'flash".  Lástima que no saqué más que tres o cuatro fotos antes de darme por vencida. Resulta que lo que vive adentro es distinto que lo que se halla afuera.

Estas dos fotos tienen un anélido de tubo "plumero", mostrando su flor rojo, y una anémona "Metridium senile", y un poco de alga "lechuga de mar".

Crunchies

The sandstone shore around the glacial erratic I visited last week, exposed at mid-tide, is densely populated by large barnacles. Millions of them; billions, maybe.

Thatched acorn barnacles*; one small patch.

I felt guilty, walking across this beach: crunch, crunch: at every step I could hear breaking shells. I tried to find spots with no barnacles to put my feet down, but there were few.

At one point, I turned and examined the barnacle I had just stepped on. There it stood, undisturbed, solid as ever. How strong are those shells? I think, possibly, the crunches I heard were dead, empty shells; they seem easy to break, from the right angle. More experiments are needed.

Stone formation, with barnacles, oysters, gull and more.

Farther down the beach, below the erratic, a few slabs of stone stood like a fence against the waves. Here, I found more barnacles, and a scattering of oysters, each one firmly cemented to the rock. The dark green stuff is rockweed.

More than meets the eye.

All across this plain, and crammed into every niche in the rocks, tiny critters go about their business, dwarfed by the barnacles. Looking closely, I found hundreds of pinhead snails. (But when I brought a handful home, most of them contained miniature orange-legged hermit crabs.) In the photo above, only one hermit crab is identifiable, but most of the blue-black snails are probably hermits, too. In the lower third, left of centre, a yellow patch is made up of whelk egg cases. And here and there, limpets try to blend into the rock.

Empty barnacle shell and black rock algae.

I brought home a few barnacles to clean my tank and feed my barnacle-loving snails. Checking them over before I added them to the aquarium, I found several healthy flatworms. No matter how strong a barnacle shell may be, these worms can slither through the cracks between plates, kill and eat the barnacle inside. Some flatworms may even eat the oysters.

*Barnacles may be hard to identify, but the thatched acorn has a black feeding foot. The barnacles that came home with me all have black cirri.

Feathery cirri, spotted palps

A few weeks ago, I noticed that several of the hermit crabs in my tank had paired up, with bigger males hauling around their chosen girlfriends. So this week, I've been examining all the larger females, looking to see if they are carrying eggs. It seems to be too early to be sure; there are a couple of maybes.

Meanwhile, I took photos of several of the other tank residents. Here are two of the large thatched acorn barnacles, trolling for plankton.

The thatched acorn barnacle has black cirri.

This one houses several worms in its shell.

These tiny three-sectioned tubeworms show up in the sand, and in many of the assorted shells in the tank, including in those occupied by hermit crabs. In the sand, up against the glass wall, I can see the tiny worm; otherwise, all that I see are these two long palps. I don't know if the spots - I've never noticed them on other worms - are bits of material the worm is rejecting, or actual palp markings. I'll be watching for them in future.

Lace doily barnacle

On a section of beach that I hadn't visited before, covered with great sandstone slabs and round, polished rocks, I found many large, empty barnacle shells with lace doily edges, detached from their homes, tossed hither and thither by the tide.

It's not often that I get to examine the underside of a barnacle.

Lacy edge. Compare to the smoother, smaller barnacles on the surrounding rocks.

This is the large thatched acorn barnacle, Semibalanus cariosus. They grow up to a couple of inches across; most of the ones I found were about an inch or so across.

The small barnacles living on the rocks are the common acorns, Balanus glandula, which, at their largest, are less than an inch across; most are much smaller. These, when they die, slowly crumble away, leaving a lacy scar on the rock. The thatched acorn barnacle, instead, has a membranous base, not heavily calcified. When this rots, the shell is released, exposing the frilly rim.

Detail of the shell edge.

Barnacles and barnacle eaters

Tyee Spit serves as a breakwater between the mouth of the Campbell River and Discovery Passage, the main sea route between Vancouver Island and the mainland. Its shores, on the saltwater side, are mostly clean pebbles, scrubbed by the fast currents racing down the narrow channel; a few miles north, at Seymour Narrows, the currents reach up to 15 knots; here at the Spit, they run around 10 knots.

Sometimes, flipping stones on that shore, I find a crab or two, sometimes a limpet. But mostly, there are just more stones.

I happened to be passing a few days ago when the tide was unusually low, and saw that the lowest level of stones were rough, barnacled. I hurried down to look.

Here's one stone, and its community.

Swarming with life. Left to right; barnacle-eating nudibranchs, hermit crabs in periwinkle shells, maybe some snails in their own shells, barnacles, egg mass, Wosnesenski's isopods, "grape" seaweed.

Zooming in on the busy end. There are a couple more nudibranchs here, too. Click to see the individual eggs in the egg mass.

Look again at those barnacles above. The small, grey ones have an oval opening, and in the large, mostly dead ones (in this photo), the opening is approximately diamond shaped.

Acorn barnacles, Balanus glandula, and Little brown barnacles, Chthamalus dalli.

The grey barnacles (Little brown) is the smallest of our acorns. They are often found on rocks at the very top of the intertidal zone, where they may only be underwater and able to feed half of the time.

The larger, lighter, almost yellowish barnacles are the ones I see most often on the beach. Look closely; the plates enclosing the mouth lock together in a wavy pattern, somewhat like a W. (Or an M, if it's facing the other way.)

And here's one of the nudibranchs, Onchidoris bilamellata.

These tiny nudis (about as long as my fingertip is wide) eat the barnacles, drilling through the shell like a snail does. Underwater, they extend their two antennae and the feathery gills at the rear. Here, waiting for the tide to return, they are hunkered down, so that it's hard to tell which is the front end. (I think it's towards the right on this one.)

More low tide photos tomorrow.

Excuses

Early morning: joined Trumpeter swan counters, walked 3+ km. Saw California sea lions swimming up the channel. On the way home, saw cormorants by the shore. Went home, grabbed camera, went to stalk cormorants down the beach until they flew away. Saw raft of sea lions, 20 or more; chased them up the channel on foot and by car. Drove to pier, walked to end, hoping to see the lions arrive. Beat them, waited. No sea lions, but saw a grebe.

Came home, booted up, fell asleep at the computer. Heading out again in a bit.

So no post today.

Well, maybe one photo.

Thatched acorn barnacles, Oyster Bay.

Feet in mouths

While I've been snowed in, I've been combing through my hard drive, looking for forgotten projects, and I found a folder full of unprocessed segments for videos, some old, some very old, a few newish. Some, with minimal processing, are worth sharing.

Here's one; a look at barnacles feeding, combining a new clip with a very old one:

(I've skipped the musical accompaniment, which is time-consuming and probably adds little to the video, anyhow.)

And the snow has begun to melt, it's raining, and the snowplow has come down my street. I'm outta here!

Hungry!

Barnacles have their quirks. The large thatched acorn barnacle shuts down tightly when the tide goes out. As it comes back in, and the first waves splash them, they begin to open, tentatively. If I come too close, they see my shadow and slam their doors shut again.

Not so the little common acorn. I had them out of the tank tonight while I scrubbed the walls, and as long as they were damp, they kept on trying to catch something to eat. And they didn't mind me moving the shell they grew on, nor even the camera's flash. They couldn't quite spread their nets as far as they do underwater, but it wasn't for lack of trying.

Looks like mountain peaks, with green lava. Or tentacled Sasquatches.

By the billions

Barnacles. On some beaches, the rocks are covered with the critters. Sometimes they're like a dusting of sugar over the whole area; sometimes they're sprinkled on larger stones only. Sometimes they're a thick layer, half an inch or more deep, half eaten by gulls.

I'm always conscious, walking over these stones, of the myriads of tiny lives I'm crunching underfoot. I try to walk lightly, as if that makes any difference when you're a quarter of an inch tall and I'm an Alice in Wonderland mile high. I try to step mainly on smooth stones, when they're available. But I know my passage down the beach is marked by dead and dying crab food. (Sorry, little guys!)

Sitting on a mostly bare rock, watching a tide pool, waiting for the little leggy beasties to forget my shadow and come out of hiding, I turned the camera on the closest barnacle communities.

Barnacled rocks, upper intertidal zone, Rotary Beach.

Barnacles on a stick. Common acorn barnacles.

Barnacles on yellow goop*. Small, smaller, smallest.

Multi-generational community. Grandfather barnacles, one dead and gone. Medium- and junior-sized barnacles, pure white. And the newest youngsters, tiny brown ovals, settling in. (For an idea of the sizes, the snails are about a quarter of an inch long, or less.)

*goop. Technical term, meaning soft, unidentifiable stuff. Could be eggs, could be algae, could be sponge, could be seaweed. Could be a mix.