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.

Also present ...

And ... the rest of the animals I found on that one trip to Stories Beach, in no particular order:

A Black prickleback, Xiphister artopurpureus. Look for the thin white lines radiating back from the eye; his pal, the rock prickleback has wide pale lines in a black field instead.

Red rock crab, running for cover.

Bright yellow or greenish yellow eggs, possibly belonging to a clingfish.

A couple of tiny hermits, dwarfed by the dogwinkles and isopods around them.

Rockweed isopods come in a variety of colours, from green to warm browns, to purplish blacks. I hadn't seen one before with that distinctive dark and light green pattern. Could it be a different species? 

Unidentified sculpin.

"Coloration is often virtually useless as a tool for identification. Extreme variation is the norm." (Marine Life of the Pacific Northwest, VB62)

Purple sea star. I saw several dozen, all healthy. Good to see, after the onslaught of Sea Star Wasting Disease that wiped out so many.

Where the worms are.

According to Kozloff, these are probably the tubes of bamboo worms, hiding 6 inches or more below the surface of the sand. Some day I'll manage to dig one out, to be sure.

Purple starfish! Healthy purple starfish!

I've found about a dozen of the purple starfish, the ones most affected by the sea star wasting syndrome. And they look healthy!

The way it worked out was this: on the most recent trip to the low tide line, when I found all those six-armed and mottled stars, I waded as close as I could to the border marker. Couldn't get quite there; the water would have been up to my waist, and I wasn't dressed for that.

But I stopped there to take photos of an eagle, and then a pair of eagles perched on the top of the marker.

One eagle

Two eagles. He seems to be doing some sort of dance.

They sang a duet for a while, him squealing and her burbling, while I tried to find solid footing underwater to get a good shot. I gave up and backed off, to take a photo of the whole marker with the reflections in the water.

Striped zones: watermarks, bare cement, barnacles, and a layer of seaweed, then the shelf. Then the whole thing reverses in the water.

At home, I had other photos to sort, and too much to do; the eagles got set aside and forgotten. It wasn't until tonight, cleaning up the recent files, that I saw the starfish.

Do you see them? Look on the right-hand end of the shelf for a pile, and then scan left.

From here, they look healthy enough; properly spread out, wearing all their arms. There's even at least one young one, just under the ladder.

This makes me happy.

As I trudged back towards the distant shore, one of the eagles passed me, in a hurry.

Things to do, errands to run, chocolates (or fish) to get for her ...

More sixes!

Strange: up until a month ago, I had never seen a six-armed starfish. And this last trip to the low tide mark, they were everywhere. Almost all the clamshells I picked up held at least one, and I even found a small one floating, holding onto fine algae hairs.

Baby star, belly-up

Dark brown star. They all seem to like the hinge end of the clamshells.

Two-toned six-armed star.

Pale brown, dark brown, and grey patterns.

I also found many mottled stars, all young. And none, not even one of our usual orange or purple stars, which were the ones most severely hit by the sea star wasting syndrome. Their loss may have been the opportunity for these less common stars to expand their territory.

Aquarium sampler

The beasties in my aquarium have been busy these last few days, happy with a new batch of fuzzy eelgrass, cleaning barnacled clamshells, and taking care of their family responsibilities. (Mating, laying, and toting eggs.)  I had a list of photos I needed to take: a shrimp eating bubble shell eggs, the one-sided crab cramming food into his mouth with one pincer, a huge, dark green amphipod, the leafy hornmouth snail growing wings, a three-armed starfish, and Barney, in his brand-new outfit.

Two out of six ain't bad.

Barney wasn't co-operating; he went and hid at the back of the tank, but I only needed his jacket, after all.

"Look, Ma, no barnacles!"

It must be nice to be able to slough off old skin, and get an all-new, younger complexion again. Here's Barney, as he was a month ago:

Barnacles and algae on his back

And just look at him now!

Inside one of the barnacled clamshells that I  brought for the leafy hornmouth, I found a baby starfish with only three arms. I don't know if he's sick, and has detached the damaged arms, or if something tried to eat him. But he has a new, growing stub of a fourth arm, and seems contented in a hospital tank. If he survives, I'll take him back to the beach; we need all the immune starfish we can get.

He's an inch across.

I watched a mid-size shrimp eating bubble shell eggs. She seemed to like the jelly they're encased in; every so often, she'd spit out a whole yellow egg, and it would drift away. The hermits eat the eggs, jelly and all.

Eggs in aspic?

And to make up for the missing amphipods, etcetera, here are a few other critters:

Nassa snail, balanced on the tip of a barnacled clamshell

Hydroids, Obelia sp. The hermits eat these as soon as they finish the diatom masses.

"Cheese!"

And I still have four photos on my list. I'll try again tomorrow.

Counting stars

Another young starfish, looking healthy.

Mottled star, on stone at top of intertidal zone

In a couple of square meters of stones, I found a dozen of these baby mottled stars, from about an inch to two inches across. Two looked faded and limp, but all the rest were healthy and clinging strongly to their chosen stones. I didn't see any lesions, the first sign of disease, nor any twisted limbs.

I've found them, so far, at the deep end of the lower intertidal zone on the west side of Boundary Bay, and here, at the very top, where the tide reaches only part of each day. In between, not a starfish to be seen, though I walked back and forth across the whole length of the mid-tide zone looking for them.

I haven't seen any of our usual purple stars, neither adult nor juvenile. I hope the starfish wasting syndrome hasn't wiped them out completely.

Serendipitous goop

Ok. I've been told to stop dawdling and get on with it.

Remember the white stuff that showed up in my aquarium leavings? Maybe not. Here's what I wrote then, September 30th:

Last week I emptied the tank, washed the sand, and replaced everything. As usual, I kept out the dirty water I'd washed the sand with, and let it sit overnight, just in case any tiny snails were hidden in the gunk. Normally, the dirt settles, and the snails climb to the top, where I catch them and return them to the tank, then dump the goopy mess. 

But this time, there was a white network of fibers just on top of the settled gunk, below the inch or two of clear water. I stirred the water again, and let it sit. Two hours later, there was the net again. Three times I stirred it; every time, white lines made a road map along the top two hours later.

And here are a couple of photos:

The white stuff is all tiny, almost straight fibers, growing at both ends.

Growing and spreading across the bowl. This is a patch about 3 inches across, IIRC.

I asked for help. People made suggestions in the comments: marine slime molds, mineral precipitation, salts. Nothing worked out.

Then, reading the article about sea star wasting syndrome by Ron Shimek, I found photos, a description and a reason that matched what I had found. They're bacteria; Beggiatoa sp.

The Reef2Rainforest photo:

Bacterial mat, in the wild.

"The black surface and white bacterial mat is exactly what would be predicted after a major mortality event in the sediment. The black sediment is made in anaerobic environments by sulfide loving bacteria. It is the result of significant decomposition in the sediments proper- where animals died and are now decomposing and releasing a lot of nutrients from their rotting bodies. ..." (From the photo text.)

The white is a characteristic bacterial genus named Beggiatoa. It has several species that metabolize hydrogen sulfide and decomposing critters. (From the caption of another photo.)

The mat in my bowl was on the gunk that I'd collected from washing the sand and the filter in my aquarium. It would have decomposing critter food, mostly shrimp pellets, and rotting eelgrass and sea lettuce. I could smell the shrimp, faintly. I had poured off the clean water as the muck settled, so there was only an inch or two of water over the black stuff; a concentrated mess of rotting animals and plants. It would be more acidic than the clean water I replaced in the tank; Beggiatoa likes acidity.

Beggiatoa lives in freshwater and marine environments. It is present in all the world's oceans, from shallow intertidal waters to the bottom of the deeps. It would be found in the stuff I bring back from the beach, but not in a concentration sufficient to form this sort of mat until I isolated it. I have tried to see if I could recreate the conditions and grow another batch, but not so far.

And they're fascinating bacteria! They are one of the largest prokaryotes (bacteria and similar organisms); up to 200 microns in diameter. That's 2 millimetres, the length of a small carpet beetle. And each filament may grow up to 1 centimetre. No wonder I could see them with the naked eye!

The metabolism of prokaryotes is far more varied than that of eukaryotes (That's everybody else, including us. -Me), leading to many highly distinct prokaryotic types. For example, in addition to using photosynthesis or organic compounds for energy, as eukaryotes do, prokaryotes may obtain energy from inorganic compounds such as hydrogen sulfide. This enables prokaryotes to thrive in harsh environments as cold as the snow surface of Antarctica, studied in cryobiology or as hot as undersea hydrothermal vents and land-based hot springs. (From Wikipedia)

Most Beggiatoa don't need organic food, nor sunlight, to grow.

They are one of the few members of the chemosynthesizers, meaning that they can synthesize carbohydrates from carbon dioxide and water using energy from inorganic compounds. Beggiatoa are found in polluted marine environments, and can be seen by the naked eye as a white filamentous mat on top of the water as a sign of environmental deterioration. (From MicrobeWiki.)

Not all Beggiatoa are white; some are yellow or orange; the white comes from granules of sulfur stored in the filaments.

As I saw, the filaments move about, both spreading, gliding along, and moving vertically. (How they do this, I couldn't discover.) "They respond to oxygen, light, and presumably sulfides."

They prefer the interface between a solid sulfide-containing base and oxygenated water, and use elements from both. In some situations, the surface sediment is oxygenated during the day, due to the the activity of algae in the sunlight. Then when the sun goes down, the oxygen is depleted and the sediment becomes anoxic. Beggiatoa pick up sulfides in the anoxic zone at night, then combine their sulfur with oxygen from the water in the daylight. A short video on YouTube shows this process.

They grow where there is an abundance of rotting organic matter, where the decomposition processes have resulted in an acidic, anoxic, sulfide-rich environment. This means that they may be a marker for pollution, such as sewer outfalls, or die-offs. But they do not contribute to the pollution; rather they help to return the area to a condition usable by more "normal" life forms.

So, while they showed up where the sea stars are dying, they are not the cause. Scientists are still looking. (Maybe it's a virus.)

More info.
The Genera Beggiatoa and Thioploca
And the original article, again.

Underwater epidemic

Or, The rotten egg zone, Part II
(Part I, yesterday)

The bad news first.

The starfish are dying.* Up and down our coast, from California to BC, millions of starfish and sunstars are curling up as if in agonies, losing arms, and then quickly dying. The cute little brittle stars are infected; sea cucumbers are spilling their guts and rotting. No-one seems to know precisely why.

Affected sea stars typically first contort and twist, and white lesions appear on their bodies. Their usually firm, meaty bodies deflate and waste away. Arms fall off and walk off on their own. The animal loses its ability to hold on to rocks or pilings. Its body falls apart in pieces, and finally dissolves. Within weeks, only a ghostly white print will remain, and then nothing at all. Entire communities are wiped out, as if they never existed, (SeattleTimes)

(Stories, USAToday, SeattleTimes, PBS.)

One of the scientists trying to find out what's happening, and why, is diving photographer Jan Kocian, co-author of a Reef2Rainforest blog. I found an article there, about a series of dives in Puget Sound, off Whidbey Island, just a short distance south of here,

. . . with the objective of obtaining photographic evidence of, particularly, the sea-star wasting disease epidemic . . .

He discovered masses of dead and dying brittle stars. It's a gruesome read, and the photos are frightening, but if you can stomach it, it's worth the effort.

Here's the gist of it, though: Kocian made a series of visits this September, finding sick sea stars, then dead sea stars, dead clams, dead and dying sunfish, dead sea cucumbers, dying sea urchins, worms, and more. By the end of the month, some areas seemed to be recovering after a storm which cleared the water, but further off-shore, the carnage continued.

The full extent of the dead area, and the reason for the mortality, remain indeterminate. Typically in Puget Sound, the benthos is very rich, so that a mortality event such as this may take several months for even partial recovery.  Although the substrate will appear to recover in a few months, quantitative sampling will show the benthos make take two or more years before it has returned to normal.

Many scientists studying this believe that it may have something to do with the increased temperature of the water; even a portion of a degree, on average, can have a major effect, stressing the animals and promoting the growth of bacteria. (I read on another website that some sea stars recovered when the temperature dropped.) Or it could be a bacterial infection, an underwater epidemic. Or ...

The cause could be a toxins, a virus, bacteria, manmade chemicals, ocean acidification, wastewater discharge or warming oceans. "We're not ruling anything out," Raimondi said. (USAToday)

I've found a few dead starfish on the beach at Boundary Bay recently, but they had all their arms, and their deaths were probably, I hope, due to more usual causes. And the stars that came home with me a few weeks ago seemed healthy. I keep hoping.

Ok. Now the good news.

After reading all this, I examined my three mottled sea stars carefully. They look fine. They're eating and growing and making a general nuisance of themselves. I don't see any early lesions, but I'm making sure to keep them cold and change their water frequently.

And I found the answer to a question I've been asking. As Ron Shimek, Kocian's colleague writes,

As is often the case in a study such as this, serendipity will rear its head, and wholly unexpected observations will be made.

And I'll leave my discovery for tomorrow.