An assortment of rocks

This latest low tide day, I visited a section of beach that I'd never been able to reach before. And there were rocks. So many different rocks! Here are some of them, and I'll leave the critters for tomorrow.

Tide's still going out. In this area, mostly seaweedy rocks.

Coming back an hour later, this was halfway up the beach.

10:40 AM. Starting off, walking down to the edge, on a causeway of rounded "cookie" stones. This is as far as I'd been before.

10:48. Still underwater. An unusually-shaped stone, clean and blue, two hands'-breadth. I saw no others like it.

12:21 PM. On my way back up the beach, at mid-tide level. Oyster-bearing rocks.

Sorry; not in chronological order. 11:20 AM. Getting near the low edge. So many rocks bear these holes; as if a giant had been bouncing on a pogo-stick.

And each hole was a mini tidepool, where mobile animals waited out the dry spell. Here, purple sea stars, an anemone, a hermit, in a hole about 15 cm. across.

Near the top of the intertidal zone, were more of these large "cookies".

And they hold somewhat barren tidepools.

Just another glacial erratic. The barnacle incrustation more or less indicates the usual high tide level.

A first-year Bonaparte's gull. Large flat areas of the lower intertidal zone are covered with slippery sea lettuce.

Ok. There were two reasons I'd never been able to reach this part of the shore before. First, obviously, because I'd never come there when the tide was this low. And secondly; footwear.

The areas that look easiest to walk on; those flat, green spaces, under a cover of pretty sea lettuce; they almost look like mowed lawns. They're not. And they're dangerous. With every step, your foot slides out from under you; it's like the slickest of slick ice.

And some of the bumpy, rocky areas are just as bad; there's the sea lettuce coating on top of rocks that roll out from underfoot. I've fallen a few times, not something I want to repeat.

But this time (why didn't I think of this long ago?) I wore ice cleats on my thrift-store sneakers; those wire and rubber attachments that go on over whatever shoe or boot you wear, advertised as winter gear. (Like these.) And with those on, I could walk normally, everywhere. Yay! I'm thinking now of another beach, one I've avoided before; not any more.

Tomorrow; the critters that live here.

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Cuando la marea estaba a su nivel más bajo, el sábado pasado, pude visitar una parte de la playa donde nunca antes había estado. Encontré gran variedad de rocas, todas diferentes. Aquí hay algunas, y dejo los animalitos para mañana.

1. La marea llega a la mitad de la zona intermareal. Estas rocas luego estaban totalmente expuestas.
2. Cuando pasé por aquí una hora más tarde, esto estaba a media playa.
3. Apenas empezando; este "camino" de rocas planas, arenosas cruzaba la zona alta. Hasta aquí yo había llegado antes. 10:40 AM.
4. Una piedra bajo el agua. No vi ninguna otra parecida. Mide unos 20 cm.
5. 12:21. Regresando hacia tierra firma ya. Hay muchas piedras cerca de la mitad de la zona como estas, cubiertas de bálanos y ostiones. (Que hasta parecen ser parte de la roca misma.)
6. Cerca de la zona más baja, muchas rocas llevan estos pocitos; como si un gigante hubiera estado jugando con un palo saltarín.
7. Y cada pocito se convierte en albergue para animales donde esperan a que regrese el agua. Aqui, estrellas de mar, una anémona, un cangrejo ermitaño.
8. En la zona superior intermareal, se ven estas "galletas", casi desnudas.
9. Y en estas, los pocitos intermareales contienen unas pocas algas marinas y caracolitos, Littorina sp.
10. Otro de esos bloques erráticos glaciares. Donde está cubierto de bálanos la marea alta cubre la roca.
11. Una gaviota "Bonaparte" en su primer año. Grandes secciones de la zona están cubiertas de lechuga marina, muy resbalosa.

Por dos razones nunca había visitado esta parte de la playa antes. Primeramente, claro, porque nunca llegué cuando la marea estaba tan baja. Y, segundo, no llevaba calzado adecuado.

Esas areas que parecen buenas para caminar; esos espacios planos, verdes, cubiertas de la bella lechuga de mar, que casi parecen céspedes bien cortados, no lo son. Son peligrosas. Con cada paso, tu pie resbala; es como caminar en el hielo más resbaloso posible.

Y hay sitios con rocas pequeñas, rocas redonditas, que son igualmente peligrosos; la lechuga de mar cubre piedras que se rodean bajo tus pies. Me he caído algunas veces; no es algo que quiero repetir.

Pero esta vez (y ¿porqué no se me ocurrió antes?) llevaba tacos de agarre para hielo bajo mis zapatos; un arreglo de alambre y hule que se fija sobre cualquier zapato o bota; los venden como equipo para invierno. (Como estos.) Y con esos puestos, pude caminar como sin nada, en todas partes. ¡Excelente!

Para mañana; las criaturas.

On the edge

When I visit a beach at a low tide, the first thing I do is walk out to the very edge of the water, and stand there for a couple of minutes, watching to see if the tide is coming or going, to calculate how much time I have to poke around. On a flat beach, an incoming tide can race, sometimes faster than I can walk safely; it doesn't do to get trapped.

Here, the tide was just about to turn; each tiny wavelet reached a level a hair's breadth lower than the previous one. Going out, but barely.

So: water's edge photos.

Intersection. Sand to my left, seaweed and stones to my right. A crow with something yummy.

Flat, but stony and slippery. Glacier scrapes. The area I left for next time, when the tide is still going out and I don't have to hurry.

Not the head of a giant seal.

Eelgrass being pushed towards the shore.

Last month, I was wondering how the eelgrass left on the sand by the outgoing tide ended up mainly pointing inshore. Now, with the water neither coming nor going, I watched several clumps of eelgrass still underwater. And they all floated with the roots towards the water, the tips towards shore. With each incoming wavelet, they lifted slightly, swished shorewards. As the waves retreated, they settled on the sand. So the outgoing water wasn't moving them, only the incoming waves.

That would explain the huge rows of piled seaweeds at high tide line after a storm, too. I've often wondered about that. Outgoing water pulls down towards the sand (or rocks), incoming waves lift and push.

Starfish looking for shelter beside the wrong rock.

Most of the starfish I passed had hidden themselves on the shady side of rocks with tidepools. A couple were just too far away and lay exposed on the sand, but still close enough to the water that the incoming tide would cover them in short order. They'd be ok. They're an intertidal species, adapted to survive several hours out of water.

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Cuando me encuentro en una playa con la marea baja, lo primero que hago es caminar hasta el mero borde del agua; allí me detengo unos minutos, observando para ver si sube o si baja el agua, con el fin de calcular cuanto tiempo me queda para explorar. En una playa poca inclinada, la marea, subiendo, puede correr, a veces más rapidamente de lo que yo puedo caminar con seguridad.

Este dia, la marea estaba casi a su punto más bajo; cada olita alcanzaba un nivel apenas milímetros más bajo que la ola previa. La marea salía, pero estaba al punto de volver.

1. Donde se encuentran dos tipos de playa; a la izquierda hay arena limpia; a la derecha, rocas y algas marinas. Un cuervo trata de abrir algo, un mejillón, tal vez, o un caracol marino.
2. Esta parte de la playa es resbalosa, llena de piedras movedizas; terreno formado por glaciares camino al mar. Un sitio que dejé para otro dia, cuando pueda seguir la marea mientras bajaba, para evitar apuros.
3. No es la cabeza de una foca gigante. Aunque así parece.
4. Hierba marina Zostera, empujada por las olas, apuntando hacia la tierra. 
   
   El mes pasado, me preguntaba como es que la hierba dejada en la arena por el agua que se aleja de la playa reposa apuntando hacia tierra firma. Ahora, cuando el agua ni venía ni se iba, observaba varios grupos de esta hierba que seguían bajo las últimas olitas. Y todos flotaban con las raices mar adentro, las puntas hacia tierra firma. Con cada ola, se levantaban las hojas un poquito, moviéndose hacia la playa. Y al regresar la ola, se asentaban sobre el sustrato. Así que el agua que se retiraba no las empujaba, sino solamente las olas que se rompían en la arena.
   
   Eso explicaría también los montones de algas marinas muertas que quedan a la linea de altamar después de una tempestad, algo que me ha intrigado muchas veces. El agua que se va arrastra la hierba hacia abajo, contra el sustrato; olas que vienen la levantan y la impulsan hacia la tierra.
   


5. Estrella de mar, buscando albergue al lado de una roca inadecuada.

La mayoría de las estrellas de mar que vi se habían escondido en las pozas mareales en la sombra de rocas grandes. Unos cuantos les había sorprendido la marea demasiado lejos de las piedras y se quedaban expuestas al aire y al sol. Pero estaban suficientemente cerca del agua para que la marea les cubriría en poco tiempo. Son una especie intermareal, y están adaptadas para sobrevivir varias horas fuera del agua.

Orange, shading to purple

 More low tide findings:

Sea star country: flat base, lots of rocks to hide beneath. Stories Beach.

An orange sea star, Pisaster ochraceus.

And a purple one. Also Pisaster ochraceus.

The species name calls them ochre, which sort of covers the bright orange ones. But most of the ones I see on our beaches are purple.

But on this visit, most of the purple ones were well hidden down in the dark, jammed into tight cracks. The orange ones didn't seem to mind the light.

One orange sea star, half in the shade, but still exposed.

I asked Google why ochre sea stars are usually purple and found several possible causes.

Oregon Coast Aquarium discusses two studies examining the situation.

A 2006 study done by researchers from UBC, University of California and the University of Washington suggests that diet may be a factor:

These voracious predators feed on mollusks and crustaceans in intertidal areas. Those that have access to mussels (Mylitus spp.) absorb red and orange pigments known as carotenoids from the flesh of these bivalves, the researchers argued. Ochre stars in isolated inlets didn’t have abundant populations of mussels to prey on, and fed more frequently on barnacles. Barnacles lack carotenoids in their flesh, so stars that feed on them don’t accumulate the pigments and are predominately purple.

And researchers at University of California, California State University and Duke University ... found that the bigger the stars were, the more likely they were to be orange. And when arms of individual stars were lost and in the process of regenerating, the new arms were often tinged with purple. This suggested, the researchers argued, that purple might be the “default” coloration of the species.

And then there are other ideas. Like this one, which ties into what I observed this week:

Some have hypothesized that lighter hues might offer increased solar reflectivity during exposure at low tide ... 

And, as always, "They stressed, however, that further study is needed ..."

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Otros encuentros a marea baja:

Primera foto: el habitat preferido de las estrellas de mar; suelo liso, muchas piedras grandes en donde esconderse. La Playa "Stories".

Segunda foto: una estrella de mar Pisaster ochraceus, color anaranjado.

Y la tercera, una estrella de mar de la misma especie, pero color mora.

El nombre de la especie las llama "ocre", que es un color que más o menos linda con el anaranjado. Pero la mayoría de las estrellas que veo en nuestras playas son de color morado fuerte.

En esta visita, casi todas las estrellas moradas que vi estaban bien escondidas debajo de las rocas, en lo más oscuro. Las anaranjadas parecían contentas de estar a pleno sol.

Cuarta y quinta fotos: otras estrellas anaranjadas.

Le pregunté a Google porque las estrellas denominadas "ocre" son casi siempre moradas y hallé varias causas posibles.

El Acuario de la Costa de Oregon tiene una discusión de dos estudios sobre el tema.

Una investigación hecha en 2006 por investigadores de las universidades de Colombia Británica, de California, y de Washington (el estado) sugieren que la dieta puede ser una causa:

"Estos depredadores voraces se alimentan de moluscos y crustáceos en las zonas intramareales. Los que tienen acceso a mejillones (Mylitus spp.) adquieren pigmentos rojos y anaranjados, conocidos como carotenoides, de la carne de estos moluscos bivalvos, opinan los investigadores. Esrellas ocraceas que viven en bahías isloladas no tenían una población abundante de mejillones, y por lo tanto, comían bálanos. La carne de los bálanos no contiene carotenoides, así que las estrellas en esta situación no adquieren los pigmentos y la mayoría son de color morado."

"Y los investigadores en las Universidades de California, del Estado de California, y Duke ... descubrieron que entre más grandes eran las estrellas de mar, más de ellas eran anaranjadas. Y cuando los brazos de estrellas individuales se habían perdido y nuevos brazos estaban creciendo, éstos tendían hacia lo morado. Esto sugiere, dicen los investigadores, que morado puede ser el color predeterminado de la especie."

Y mencionan otras ideas, como ésta, que apoya lo que yo he observado:

"Algunos han hecho el hipótesis que los colores más claros tal vez reflejan más los rayos del sol mientras las estrellas están expuestas durante la marea baja."

Y como siempre, "hicieron hincapié en que se requieren más investigaciones."

Two starfish under rocks

Just above the low tide mark on Stories Beach, I peered into the crack between two rocks. Deep inside, seen only as a brownish patch, there was a starfish. They do love to hide away from the light!

The camera could get closer, and sees better than I do in the dark.

The brownish patch turned out to be an orange and purple starfish, with an unusual pattern. Also present: pink-tipped green anemones, shut down, waiting for the water to come back.

Getting closer.

Risking my neck, balancing on small points of rock, to get closer still. The tube feet underneath are visible.

Under another rock, a few metres away, I found a purple starfish.

This one has the usual pattern; purple on purple, with white spots.

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Cerca del nivel más bajo intramareal, me agaché para examinar la grieta entre dos rocas. Y allá adentro, tan protegida de la luz, estaba una estrella de mar, apenas visible como una mancha de color café. Siempre se esconden lo más posible de la luz del sol.

La cámara pudo llegar más cerca, y ve mejor que mis ojos en la oscuridad.

Las fotos 1 a 3: la estrella de mar. Tiene un diseño un poco diferente de lo normal, con manchas anaranjadas y dibujitos en color morado. Cuando me acerqué a lo máximo (arriesgando una caída, inclinándome apoyada sobre dos puntitos de piedra) la cámara pudo captar la textura de la parte inferior.

La cuarta foto es de una estrella de mar que se escondía bajo otra roca. Tiene el color y el diseño que se ve normalmente; lineas de una violeta oscura con puntos blancos, sobre un fondo morado.

Recovery

This made me happy. It used to be, years back, that on any shore, from mid-tide on down, I would see mounds of purple and orange starfish. Then came the epidemic of starfish wasting disease. The purple starfish and the sunfish curled up, fell apart, and died in the millions. And then there were none.

Some days, in the last year, I've seen one or maybe even two starfish and rejoiced. This time, at the very bottom of the low intertidal zone, the starfish are back and healthy, to boot.

Purple starfish, Pisaster ochraceus

In a crack between two rocks, a lineup of starfish, with a red giant chiton.

Purple and orange. One species, two common colours. With green sea urchins.

More purples. That round spot is a hole in the sandstone with another starfish tightly coiled inside. On the far left, there's a small leather star.

So many starfish! Almost like old times! It got so that I was walking past piles of starfish without stopping to take their photos.

A rare pinkish-brown coloured star, with another of the purples.

Leather star, Demasterius imbricata.

The pale yellow circle on the top of this leather star is the madreporite; all starfish and other echinoderms, like the sea urchins and the sea cucumbers, have one, although not always so visible. The madreporite is a plate of porous calcium carbonate which funtions as a sieve regulating the water pressure in the starfish's vascular system.

Two leather stars and green sea urchins in another rock hole.

And not one sign of a rotting arm! So good!

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Esto me hizo feliz. Hace años, acostumbraba ver montones de estrellas de mar, de color azul púrpura o anaranjada, en todas las playas mientras se bajaba la marea. Y luego, por el año 2013, surgió la epidemia de desgaste de estrellas de mar, en la que se torcían y se desbarataban los brazos de las estrellas y los soles de mar, resultando siempre con la muerte del animal. Millones perecieron. Y luego, no se encontraban estrellas sanas en nuestras costas.

Algunas veces durante el año pasado, encontraba una o tal vez hasta dos estrellas cuando la marea bajaba, y me regocijaba. Ahora, en la parte más baja de la zona inferior de la intramareal, han regresado las estrellas, y todas parecen estar sanas. ¡Tantas eran, que por fin, pasaba a su lado sin pararme a sacar fotos! ¡Casi como los tiempos antiguos!

Fotos: estrellas de mar Pisaster ochraceus, anaranjadas y violetas, y estrellas "de cuero" Demasterius imbricatus, con su diseño de manchas anaranjadas. Y algunos erizos de mar verdes.

En la primera de las estrellas "de cuero", se ve claramente un círculo de un color más pálido. Esta es la madreporita, un órgano común a todos los equinodermos, tales como las estrellas de mar, los erizos y el pepino de mar, aunque en algunos apenas se puede ver. Es una placa porosa de carbonato de calcio, que sirve de coladera, y ayuda a mantener la presión del agua en el sistema vascular del animal.

On Willow Point

The beach sometimes looks bare. A sprinkle of sand on sandstone, a few scattered rocks, a smear of sea lettuce, leftover tidewater; not much else.

Willow Point beach, looking towards Quadra Island and, in the distance, the mainland.

But slow down, crouch, look underneath rock overhangs, behind the stones ... the barren beach is full of life and colour.

Purple starfish, clinging to the bottom of a rock. With pink-tipped green anemones for company. And limpets and barnacles, of course.

An assortment of seaweeds. Green sea lettuce, yellowish rockweed, one (or two?) of the many stringy, bushy brown algae. a blob of sea cauliflower, and tasty-looking succulent seaweed, Sarcodiotheca gaudichaudii. (I love that name!)

Sea cauliflower with a garnish of sea lettuce, accompanied by rockweed leaves and brown alga shreds.

Rocks and mounds of brown algae, crawling with hermits and crabs, isopods and snails. Good feeding grounds for a pair of mallards, now leaving their unfinished dinner in haste because of that pesky photographer. (They came back as soon as I walked away.)

Decorator colours

The plumose anemone in my tank has a brown column and  beige tentacles, a common combination. Often, though, they are white on white; a white column, and whiter tentacles. I had never seen one with a green head before.

Plumose anemone, Metridium senile in the tidepool under the glacial erratic. With green tentacles.

I browsed images on Google; I found a few white "Mets" with pale green tentacles, always in photos taken during a dive. This one is in a few inches of water. And that was the colour as my eyes saw it; I used the flash, because the anemone was in shade, but those tentacles were a definite blue-green.

Another. This one has white tentacles, but the base is a pale blue.

This one matches the one in my tank. Some of the red blotches around it are tubeworm "flowers".

Another "normal" M. senile.

Deep under the rock, starfish wait out the dry spell. The flat, spread out anemone seems to be a burrowing anemone, with its mouth exposed. Must have just eaten something. Maybe one of those little fish?

More vivid colours. A deep pink tubeworm, still fishing while the water lasts. The pink-tipped green anemones below have shut down for now.

Even the hermit crabs are wearing party colours. I spotted this one with those bright blue pincers, like the one I brought home last week.

Three hermits, a dead kelp crab,and limpets. The deep red  critters at bottom right are not fish; they're shreds of seaweed.

Kelp crabs are usually a dull olive green, sometimes greenish brown. I don't know if this one was joining the explosion of colour in his lifetime, or if there's some sort of blue-green algae that took over his carapace and legs after he died.

This photo was taken aiming straight down into a foot-deep rounded hole. There are many of these near the bottom of the intertidal zone; circular holes, smooth-walled, looking like someone at some time removed a bowling ball from the rock. What causes this? I don't know.

I am always on the lookout for nice whelk shells for my hermits at home. Here, around this erratic, there are many whelks, all healthy and shiny, but no empty shells. And almost every hermit crab I saw was wearing a smashed and broken shell. What happened to the fresh shells?

I feel sorry for these hermits; the ones I brought home were quick to switch into intact shells; they do know the difference. I almost feel like collecting some decent shells from my tank and spreading them around this tide pool. Or would the tide immediately haul them off and slam them against the rocks until they were full of holes?

Questions, questions.

Fishy

Growing up, I learned to call them fish: starfish, jellyfish, even sunfish. Why, I wonder? They're not fish; it makes no more sense than if I were to call the crabs, "crabfish" or "hermitfish". And I had also learned never to call a whale a fish; that would be silly.

Common names are sometimes really odd.

This is a purple sea star, Pisaster ochraceus, or, translating the Latin, ochre starfish. Yes, the "fish" part is there in the Latin, too; Pisaster is a combination of Piscis, fish, and Aster, star.

Scientific names are sometimes really odd, too.

I had automatically named the file, "Starfish". The habit is deeply ingrained.

And these are moon jellies, Aurelia labiata, not jellyfish. "Labiata" derives from the Latin, "Labiatus", lip. There is probably a good reason for that name, but I can't find it.

At the border between gentle waves and wet sand.

A second moon jelly, exposed on the sand at low tide.

The four lilac semi-circles are the animal's gonads. The female's are usually a paler pink, or even whitish.

Just a reminder:

... plastic bags that end up in the ocean often look like jellies to animals that depend on these drifting creatures for food. Thousands of turtles and birds die each year after swallowing indigestible wads of plastic mistaken for jellies. (From Monterey Bay Aquarium)

If you see a plastic bag on the beach, pick it up and trash it, please!

Wrinkly, puffy skin. Purple

I don't know why I took this photo of a sea star. She was in an awkward spot, wedged into a crack I could barely reach, and I was sure to find more, I thought. (I didn't; the tide caught me delving under stones and I had to rush away.)

I almost tossed the photo, but then I looked at it more closely.

Pisaster ochraceus. The arms are as usual; hard, knobbly skin. But around the central portion, the skin is puffy and either lined or ridged. (It helps to click for the full size photo.)

Zooming in on the original. I think those are curly ridges.

I'd never noticed skin like this on a sea star before. I looked up a bunch of my old photos; none of them are puffy. On the web, I found one with the wrinkles, a close-up of the skin taken in 2011. By the accompanying photos, I think it was somewhere on the Washington-BC coastline; the photographer doesn't say.

Now I find that I must head out again next low tide, carrying a hand lens to examine every sea star I can find.

By the way, while you're here, notice the unusual green wrists of the purple shore crab nestled beside the star.

(I've decided that I should really be recording the exact location of the intertidal critters I photograph; from one beach to the next, the communities are so different. This was taken almost exactly on the 50th parallel north.)