On the wall

First day of snow this year. It's melting already tonight.

And first winter for this black squirrel.

"Can't see me! I'm hiding behind this pile of white stuff."

The green vine is sausage vine. A shade-loving, cool-climate evergreen. Maybe it will produce fruit one of these years.

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.

The rotten egg zone

Boundary Bay is about 13 kilometres (8 miles) across at the base, and encompasses about 100 square kilometres. In the centre, there is deep water, but most of the northern end is a flat intertidal plain, filled with silt from two rivers and many creeks.

2009 Google map. The intertidal zone is shaped somewhat like an amphipod, looking towards the east.

The head and the spine of the amphipod are mud. Deep, maybe waist-deep, sticky, squelchy mud, continually replenished with run-off from the farms and bogs of the Delta brought in by the Serpentine and Nicomekl Rivers at the "head" end. It's bird and worm country; people can't walk there, don't even take their boats and paddle boards in that direction.

As the silt merges with the sand along the western shore, the mud develops a variety of disagreeable odours. Sometimes there are dead zones, where clams and crabs lie dead on the surface; the air smells of rotting flesh, choking and impregnating our clothes. At other times, everything smells fishy or of untamed compost heaps. These are often the result of human pollution; fertilizer and industrial contaminants, construction debris, oils and paints.

The more common rotten egg smell of hydrogen sulfide is almost pleasant in comparison. It is a sign of abundant organic matter, teeming with busy, happy life.

It all depends on the size of the mud particles. Where the sand is coarse, water flows through, carrying oxygen to the tiny critters living there. Mud worms in their burrows dance a slow, sinuous dance, pushing the water along; clams squirt water and sediment as they move about. We see it as clean sand. It's soft underfoot, but not sticky; we dig in it, walk on it, sunbathe on it. If we notice any odour, it is the fresh tang of salt water.

Where fine silt clogs the water passageways, the water becomes stagnant, and free oxygen is depleted. Life goes on, even in these conditions; after all, there's plenty of food. It just has to be metabolised differently. Some of the animals living here use hydrogen sulfide as an energy source. The sand, to us, looks mucky and off-colour. And smells of rotten eggs. We look for better places to play.

Sticky sand/mud. Lugworm heaven. 2008

Slightly wetter muck, with worm poop.

Where the oxygen levels are lowest (anaerobic or anoxic zones), the muddy sand forms a black layer, sometimes just below the surface of the tide flat, or in other spots some 6 inches down, depending on the ratio of sand to silt.

Further south along the shore of the Bay, although the silt doesn't reach quite this far, and we have acres of clean sand, there are still pockets of black sand underneath. Around the worm "mountains", there is often a circle of black sand that the worm has eaten and ejected to the surface.

If we grab a handful out of the black layer, it feels firmer than the sand around it, and, again, it smells of rotten eggs.

And this brings me to the mysterious network stuff I was wondering about a couple of months ago. Continued tomorrow.

Summery interlude

It rained last week, and it's raining again now. The weather people say it's going to get even wetter for the rest of the week. Normal Lower Mainland winter weather, in other words.

But just for Saturday, the weather gods relented and gave us a glorious sunny day. I crossed to Victoria and came back at night under clear skies. It started to rain as I hiked across the terminal parking lot to find my car, back in Tsawwassen.

I even found a few clean spots on the ferry windows:

Halfway across the Strait of Georgia, dodging islands. I grew up with a view like this just outside my bedroom window, a ways further north. I miss it.

A mini-island, or spit, depending on the tide. Mostly rock and hardy, scratchy trees.

Zooming in on that islet. The thick Pexiglass windows of the ferry serve as a filter, making this seem more like a painting than a photo.

Just outside the Schwartz Bay terminal, on Vancouver Island.

A Skywatch post.

Green and white

Swirling water as the ferry settles into the landing.

Foam mixed into the water makes it milky and green. Before the ferry arrived, it was a clear dark blue.

Detail

I took a quick dash over to the island for an afternoon and evening. A beautiful trip; the sun shone all day. Photos tomorrow, and then I have an old mystery, explained, for the next day.

Salt-water chameleons

Maybe it's because they're transparent. Maybe it depends on what they're eating this week. Maybe it's where they've settled. Maybe they're akin to mood rings: whatever the reason, the orange-striped green anemones, Haliplanella lineata, in my tank are never the same colour twice in a row.

This is the largest of these tiny anemones, parked for the moment on sea lettuce in a bed of deep red Turkish towel and red leafy algae.

Open, showing mouth lining. Pinkish today.

Almost closed. Just the slightest hint of orange. And the green base is blue.

I don't know what those white lines inside the closed anemone are. Ingrown tentacles, maybe?

Tomorrow I'll be travelling, and won't be posting. See you Sunday!

Blue blood and dinner forks

My hermit crabs have come down with spring fever. Most of the larger males are courting; some trying to convince a female to allow herself to be carried, others, each clutching his chosen mate, sitting on high places, waiting for her to molt.

Hopeful parents, on top of the big abalone shell. Waiting.

And as always, there has been some competition for mates, a few tug-of-wars with the unfortunate female as rope, a couple of frantic chases, and, sadly, a few duels; pincers at a quarter inch. A smaller male was the loser in one of these battles, and limped away with two legs on one side, none on the other. And no pincers. I thought he would die, but he's tough.

He still gets around; slowly, dragging his over-sized shell behind him. He rests in the shadow of a kelp holdfast or in a tangle of eelgrass roots, out of the way of his more active neighbours. But his blue and orange flags still wave happily, he manages to find food and eat it, even without his hands.

What's more; twice I've seen him "flirting"; face to face with a female, trying to hold the lip of her shell in the customary fashion, without success, not having the required pincers. The girls were not impressed and soon wandered away.

There's hope for him; if he can hold out until the next time he molts, he will have grown back some of the missing limbs.

I've been keeping an eye on him, making sure food lands in his vicinity morning and evening, admiring his persistence.

I noticed a blackish spot on his maimed side. A lump, glossy blue-black, the blue-black of a mussel shell. A parasite? Or what? I kept watching, trying to get a photo or get a clear view with my hand lens, worrying.

With the extra light from the flash, the addition is deep blue.

I finally got close enough to see; it's a forming pincer arm, still coiled, still without movement, but with all the parts; joints and pincer tips, well formed. Hermit crab blood is blue, which may explain the colour.

The white ovals behind it are the stubs of the missing two legs.

The stub of one leg is clearer here.

How does a hermit crab, bereft of hands, manage to eat? This guy holds onto something solid with one back leg, drags over a chunk of food with the pointed tip of the second leg, and then uses his first set of mouthparts, or maxillipeds, to grab it and bring it to his mouth.

The first two maxillipeds serve as forks.

He's lucky to have three separate sets of maxillipeds; the inner two sets do the work of jaws. So he won't starve.

November afternoon, with mallards

Cougar Creek Park, south lagoon.

The water is high; the beavers have been hard at work making dams.

Off the beaten track

I spent much of today on the road, hurrying along freeways and up city streets, racing the clock. On the way home, I was feeling very sleepy, and on the spur of the moment, took an unfamiliar exit off the highway, and then, to get out of the way of trucks, dodged down a dead-end street, going south towards the river.

A quick walk in the cold without my coat woke me up. And my little old camera was in my purse (and the battery was charged - oh, joy!). I wandered about snapping photos of everything and nothing until my fingers went numb, then got back in the car and came home.

I liked these 4 photos.

Above a ditch full of blackberry canes, these dead fireweed stalks reach for the sky.

At the dead end of the dead end, a rough trail led to this fence, and to one of the tugboats that ply the river, in for repairs. The trees are on the bank of the river.

Frozen roses, crispy and shrunken, but still pink.

I'm back on the road home, waiting for the light at my turnoff, and looking at the back side of  Burns Bog. I love this view in winter; in the summer the skeletons of the trees are hidden behind a green blanket.

On the road again tomorrow. I hope the weather holds.

Cold weather haven

The weather has turned cold this week. At night, the thermometer dips below freezing. Where the sun shines in the daytime, it warms up, but in my shady garden, the bird bath stays frozen all day and even my winter-hardy bergenias and primulas have wilted.

Chickadees come to my door early, calling to me; "Hurry up with our breakfast!" They've got a busy day ahead, getting enough to eat to stoke their tiny furnaces overnight. After them, come the juncos and a towhee or two, poking around in the frozen earth, looking for anything edible, mostly tiny weed seeds. In my garden, the native bleeding hearts bloomed just before frost; their black seeds were ripening this week. The astilbes, the heather, and the lemon balm were still dropping seeds, too.

The smaller animals have gone into hiding. There are no slugs to be found, even under flowerpots and heavy leaves. No sowbugs. No beetles. Spiders have crawled into crevices: the babies have hatched and ballooned away. The bees and wasps are gone. I saw one harvestman a couple of days ago, and a small moth last week. It's winter. The sleepy season.

I needed a piece of lumber for a small repair, and remembered I had a plank propped against the wall in the corner of the patio, behind the compost bin. I moved the bin and retrieved it. And was surprised to see small things (and some not so small) scuttle off in all directions. It's not winter yet in that protected corner.

A couple of fair-sized spiders came along with the board.

Mid-sized Tegenaria. If you look closely, you can see that the surface of the wood is covered with spider webs.

A plump cobweb spider, probably Steatoda sp. The frass on the left includes a spider leg, either the remains of a molt, or of her unfortunate mate.

Neither of these two wanted to leave their warm board. I shooed them off, and they ran to the edge and over to the underside. I flipped the board, and they moved to the new underside. Again, and again. I finally convinced them by brushing and shaking the board vigorously, and they scooted down the side of the compost bin. There's still another board back there; they've got a few weeks more before the cold reaches them there.

Rainbow leaves

They come in every colour but blue. But for that, we have skies.

One of Laurie's hostas, under a mulch donated by the trees overhead.

This one turned up by the back door, blown in from a neighbour's tree.

Detail of dead maple leaf

Sunlight through sweet gum leaves and seed pods. At the mall.

Wave catchers

Last week, I was walking along the shoreline at Boundary Bay, head bent, concentrating, hands full of bags for eelgrass and barnacled rocks, collecting goodies for my critters. Something made me look up, maybe a small sound, maybe a hint of movement, and there, on a rock barely three or four feet ahead, a half-dozen sandpipers were standing still, just, watching me.

I reached for the camera, and they all flew away, and kept on flying until they were almost out of sight.

I kept a lookout for them the rest of the afternoon, but never got so close again.

These were watching the waves near the boat launch, later, but kept moving north as I walked closer to them.

They seem so fragile, but the waves rolling in don't even make them wobble.

All facing the incoming water, except for the one watching me. Lookout duty, maybe?

And then I got too close.

Flying from sunlight into shade.

There don't seem to be as many birds on the water and beach as there have been in previous years. Mid-afternoon isn't the best time to see them, but even then, there should be hundreds, not dozens.

Role model

If barnacles could dream ...

Barnacles on crab carapace and the big burrowing anemone

I went out and bought a new tank for my critters today. It's twice the size, roomy enough for a small forest of eelgrass and a rockery (stonery?) for the hermits to climb on. And the main thing: the glass is not scratched! Several years of hermits banging about, snails scraping algae, me scraping leftover algae, and the pump sand-blasting everything had turned the glass walls hazy.

I've moved everyone into their new home, and they seem happy with it. And I'm going to bed.

Snails

Just snails.

On dying bergenia leaf

On mildewed painted wood.

That's all.

Once you get to know them ...

Starfish have always seemed to be curiously inert animals, in spite of their reputation as predators. When we pick up one on the beach, it's stiff and solid, nothing but arms covered with a bumpy skin. The only sign of life seems to be on the underside; those tube feet that cling to the rocks and refuse to let go.

So I've been surprised by the three starfish (not counting the baby) that came home on the kelp and holdfasts. In the tank, they're almost always in motion, climbing the walls and stones, investigating the pump, sliding over snails and barnacles, sometimes pausing to eat one, and even, this afternoon, trundling along a blade of eelgrass near the top of the tank.

And, underwater, they suddenly become soft and furry; the hard, spiny top is coated with a living coat, swaying in the currents; the arms are tipped and bordered with long, questing tube feet, in the shape of a land snail's eyestalk, a thin, flexible, extensible tube with a round knob on the end. But instead of two per critter, there are hundreds.

Part of an arm, underwater.

Through the glass and an inch of water, the edges are blurred, but we can see three main skin structures. The pale, traslucent orange "nipples" are dermal banchiae, gill structures, absorbing oxygen from the water. These are constantly in motion while the starfish is underwater. The white, four-pointed "jaws" are pedicellariae, little snapping pincers, which may capture small prey, or alternately, protect the other skin structures. (Could this be why we don't find starfish wearing barnacles or mussels?) Underwater, they extend enough to almost hide the spines. And, like the gills, they are always moving, snapping at anything that comes near.

Out of the water, the pedicellariae subside, and the spines are more visible. I moved the largest starfish (about 4 cm across) to a small plate, where he immediately crawled to the edge, off the white background that I'd chosen.

Two arms, showing pattern of spines, each one surrounded by a ring of pedicellariae, and with gills mainly along the outside edge of the arm. The white patch in the centre is the madreporite, the intake for the water circulation system of the starfish.

Zooming in on one of these arms:

Spines, small and large, each surrounded by biting pedicellariae. A few gills along the bottom.

Zooming in still more:

Here you can see the open "mouths" of the pedicellariae. These are two-sided; some starfish may have three-pronged "peds". The starfish is wet, but out of the water, so the "peds" are shrunken and relatively peaceful.

And the starfish has eyes! Five ocelli, one on each arm, at the tip.

Each one is well protected in a ring of tube feet and pedicellariae. They don't see much other than light and shadow.

I've been watching the three of them climb my glass walls, which gives me a good view of how the tube feet move, stretching, reaching, pulling. A starfish can move quite quickly on these, when he's motivated.

The medium star, longer-armed than the big one. The tube feet at the tip of each arm are extended mostly in the direction of travel. I saw one of these come up to an anemone on the wall; when the first tube foot touched an anemone tentacle, the starfish reacted, pulling the arm back and curling it away from the wall. Then the star changed direction, carefully skirting the danger zone.

We watched a starfish eat a limpet on the wall this afternoon. It everted the stomach, pulled in the limpet, pointed shell inwards, then after a few minutes of chewing, ejected the limpet shell, this time pointed end outwards.

I don't know what this one was eating; I just caught it in time to see its everted stomach.

Probably eating algae or something too small for me to see. There were no shell remains.

Zooming in further, to see the everted gut structure.

Here on the underside, the pedicellariae are not so obvious, and most of the structures are tube feet. They have been traditionally understood to work by suction, but recent research suggests that they expel a chemical glue, which leaves a residue on the surface.

There are only two limpets left in the tank, but plenty of snails; mud snails and Nassas, which both seem to breed here. The big anemone eats some of them, but there will be enough to share with the starfish, so no worries. Otherwise, they will compete with the leafy hornmouth snails for what barnacles I can gather.

Pathfinders

Still working on a starfish . . .

Sensory tube feet on the tip of a starfish arm.

I never imagined there was so much to discover in a simple starfish. Coming up; gills, spines, snapping pincers, red eyes, and a stomach. Tomorrow, if all goes well.

Snaky star

As soon as the holdfasts I'd brought back from the beach were out of the bag and in a bowl of clean salt water, three brittle stars squirmed out from among the roots. They were so tiny, so almost colourless, that I wouldn't have seen them if they hadn't been trying to escape the light.

The first brittle star, captured in a plastic cup. Missing half an arm.

Brittle stars are not starfish, but are related to them. They do not use suction cups on tube feet to move, but rather wave the arms about wildly to swim, in a haphazard fashion, going where the current takes them.

The arms break off easily, leaving a hungry predator with a mouth full of spines and no meat. The star grows the arm, or arms (up to 4) back. The detached arms themselves don't regenerate a new brittle star, though. (As some starfish do.)

A second brittle star, in the aquarium. Parts of two arms missing. The star-shaped opening at the centre is the mouth.

These are possibly the dwarf brittle star, Amphipholis squamata, aka  the holdfast brittle star, aka the small serpent star (for the movement of the long arms). The ones we found a few years ago in Campbell River had much longer arms, and were probably the long-armed brittle star, Amphiodia occidentalis.

Much bigger, much more wriggly. More here and here.

Within a few minutes of being placed in the tank, all three had disappeared. I've been looking for them since Brat intervals, with a lens and flashlight, but have seen no sign of them. They seem to prosper in other aquaria, so they may show up again, with all their arms intact.

I've been watching that bigger starfish; the more I look, the more interesting it gets. I just took another batch of photos, to process tomorrow, I hope.