Fish on the sand

In the eelgrass beds at the bottom of the intertidal zone, fish dart through the thickets, usually visible only as a flash of movement, a streaking silver shape dashing from shadow to shadow, or a panicked thrash to escape my clumsy foot. They're usually not the fish I see in the upper zones, the sculpins and the flatfish, but they speed away so fast that I haven't been able to recognize any.

This last trip to the low tide line, though, the shallows were littered with dead and dying small fish; I was able to identify three species.

Another Pacific sand lance, Ammodytes hexapterus. These grow to about 11 inches long, so this is a youngster.

In one small area, I counted over 50 of these, all dead, but still fresh, surprisingly still untouched by gulls or crabs. They were all young; the adults spawn and die in mid-winter here. I am wondering what caused this die-off.

A larger sand lance, still alive, but barely. The back is a glittery blue-green, which should help with camouflage in the eelgrass beds, at least from above. At night, they burrow into the sand, to hide from predators.

Mixed with the sand lances, a few darker, larger fish stood out.

Pacific snake prickleback, Lumpenus sagitta. About 8 inches long.

Another. This was still alive, but not able to swim away.

Again, these were young fish; the adults grow to 20 inches long and spawn in the winter.

One more; a beautiful singing midshipman, no longer able to sing.

A steampunk fish, looking as if he were made of riveted plates. Plainfin midshipman, Porichthys notatus, about 8 inches long.

These are night-swimming fish; during the day, they hide under rocks. I found a male, guarding eggs, about this same time three years ago, under a rock at the boat launch. He was fatter and longer than this one.

The "rivets" are lines of photopores, cells that emit light. They may help to attract prey at night. (Although we don't really know that; it's human speculation. We do like to imagine that we understand Ma Nature.)

Belly up, showing the pattern of photopores, and his delicate colouring.

Zooming in to the tail end, to show the little lights, and - look closely - tiny waving three-fingered hands, all in a row.

I didn't pick this one up; some midshipmen have poisonous spines. I'm not sure if this species does, but I'm not risking it.

And I'm left wondering why all these suddenly showed up dead, all at once. The water was clear, it smelled fresh, there was no scum or oil sheen. There is construction going on 'way back at the shore, but that's a full kilometre away. Worrisome.

It's a dog eat dog world out there.

About that family that Val ate ...

The eelgrass beds last week held a large population of proliferating anemones, riding high on the grass, feeding on the small animals in the diatom and hydroid fuzz.

Proliferating anemone, Epiactis prolifera, proliferating.

Like this one, most were adults carrying a column-full of babies and youngsters. Where they have been hiding up until now, I'm not sure; maybe half-buried in the sandy bottom, and now they have midgrated to the eelgrass to feed.

Another family, with one youngster already out on his own. The young stay on the mother's column for 3 months, then crawl away.

I transferred this blade of eelgrass to a bottle of water, and brought it home to the aquarium, where the family settled in happily.

The babies come in a range of sizes; they're not all birthed the same day.

Another view. The anemone in back has captured a chunk of hermit crab food.

Then their troubles began. The hermit crabs ripped the end of the eelgrass out of the clamshell I'd anchored it in, and it floated away. I moved it around to rest against the glass, and the mother anemone started to transfer to the wall. She would be safe there, but again, the hermits yanked the eelgrass away. I found her later, up against the back wall, busy moving onto a stone. That would have been perfect; only the crabs move stones around, and the three in the tank now are very small.

And then, before she was glued down, something moved her again and left her and her brood at the mercy of the current. Which was flowing towards the big burrowing anemone, Val, and her hungry tentacles.

Next thing I knew, Val's mouth was full. And the ends of the eelgrass were protruding. The only sign of the whole blue family was the hint of blue around Val's mouth.

Val's blue mouth. And a young hermit, trying to get at the crumbs from Val's dinner.

This morning, Val spit out the rest of the eelgrass blade, with a bit of slime, all that remains of the entire blue family.

Luckily, before the first move, two of the youngsters decided to leave home, and established themselves on the wall of the tank. They're still there, waving pale blue tentacles, eating and growing.

Young brooding anemone, not old enough to brood yet. 5 mm across the base.

Candy on a stick

"Tis the season. For laying eggs, hundreds and thousands and millions of eggs. And the bubble shells are enthusiastic egg-layers. Almost every blade of fuzzy eelgrass in the lower intertidal zone carries, somewhere, another blob of transparent jelly filled with yellow eggs.

But not all the eggs are theirs. I was surprised to see a large, pale pink decoration on one stalk in knee-deep water.

Pale pink eggs, without jelly, in messy eelgrass.

I looked for more, and found a few, some very pink, some almost white. The clumps were not like the usual jelly masses that snails leave, nor like the ribbons most nudibranchs create. These were short sausage-like tubes, glued to the eelgrass at the centre and loose at the ends; each one waved separately in the current.

But what laid these?

I found another mass in shallower water, glued to the inside of a clamshell. And with it, another of the opalescent nudibranchs, Hermissenda crassicornis. A clue!

Mother and babies?

At home, I Googled opalescent nudibranch eggs, and there they were; in most photos, the eggs were white, but some had a pinkish cast. And I found a photo of one laying her eggs, on Flickr.

I brought one of the pinker masses home to look at more closely.

Pink. Candy floss pink.

Zooming in. Hundreds of eggs in each "sausage".

I added the egg mass to my tank, but it didn't last. A few hours later, I found a hermit happily eating pink sausages. The next day, they were all gone.

Looks delicious!

Where the wild things are

The critters of the upper intertidal zone, with the exception of the insane mud snails, go into hiding at low tide; Boundary Bay becomes a wide zone of bare, grey sand. But when the tide is low enough, we can walk out to the last sandbars and the eelgrass beds between them. There, life goes on, busily, whether the water is coming or going.

These photos are in chronological order, as I walked out. Some animals only show up in the deeper areas, where the tide rarely drops below the tips of the tallest eelgrass.

Small Dungeness crabs start appearing at the inner edge of the beds. This is under about 4 inches of water.

Opalescent nudibranch, on kelp. There were many in the shallower eelgrass beds, all much more vividly coloured than the one I found last month at the boat ramp.

(More on these, later.)

Fuzzy eelgrass.

The fuzz along the blades of grass is made up of diatoms and bacteria. It doesn't look appetizing, but this is my hermits and crabs absolute favourite food. They're not the only gourmets; the fuzziest grass in this zone is loaded with bubble shells, nudibranchs, skeleton shrimp, amphipods, and other small, darting beasties. It seems that every second blade has its collection of egg masses, pink, white, and yellow; the next generation will be well provided for.

I don't know what was in that ball of pinkish stuff. It felt solid, and was firmly stuck to the eelgrass.

If you look closely at the photo, you may find the baby starfish.

Dungeness crab molt. It must be handy to get rid of your old skin when it loses its youthful smoothness.

Looking back. The photo reminds me, in tone and layout, of an old postcard in my Mom's album.

Purple sand dollar, under flowing water. This one's alive, so it still has the dark spines.

Looking north, across the bay to the hills of South Surrey.

One sandbar to go before the border marker. The water was about knee-deep from here to the bar, then the bottom drops off quickly.

Green burrowing anemone. The deep green is from ingested algae.

I found many empty clamshells; most of them contained small mottled starfish. There are three here; do you see the third?

About a third of the small starfish had the twisted, upturned armtips that may be caused by starfish wasting syndrome. I didn't see any lesions, and there were quite a few babies.

Almost every clamshell that contained starfish also held a few tiny, almost transparent shrimp. Four of them, one a female carrying young, came home with me in a handful of eelgrass. I'll have photos of these, later on.

At the outer edge of the last sandbar, as I watched, the eelgrass stretched out in the outgoing current suddenly faltered, drooped, turned back towards me. The tide was coming in. Time to go.

I had time to stop, once I'd reached shallower water, and take a couple more photos.

Blending in.

Jellyfish, alive and swimming, made visible by its shadow on the sand beneath.

I brought home a small bag of fuzzy eelgrass for my hermits; as usual, there were hitchhikers. Some of them, tomorrow.

A bubble in the hand . . .

is worth any number in the eelgrass.

It's interesting, how once you've gotten familiar with the shape and movements of a critter, that you see them in places where you looked before, without finding any. Like the bubble shell snails; I've waded knee-deep in the eelgrass beds at low tide in Boundary Bay many times, and all I saw were crabs and isopods. This last time, I recognized the bubble shells, dozens of them.

They're easy to catch; they hang out on the eelgrass blades, and when they're disturbed, they just let go and float down to the next blade. And they're just as content to land on my hand.

I got this one still on his eelgrass. He's upside-down, twisting up to get a look at me.

Setting out to explore. Isn't he a cutie?

"Hi, there!"

These snails are incredibly fragile; their shells are paper-thin, and as brittle as eggshell porcelain. Other snails have thick, sturdy shells, essential for survival in crab country. Even so, I find many empty shells, peeled back by crabs to get at the tasty meat inside. How do the bubble shells, without that protection, manage to live?

Watching them on the eelgrass, it all became clear. As long as the eelgrass in underwater, it stands upright, swaying in the current. The crabs scuttle along underneath, but only the smallest climb the eelgrass; it won't support the weight of the larger ones. Up at the top of the bed, there are no hard edges, no stones, no crabs, nothing to squeeze or bang those fragile shells.

When a bubble shell drops to the sand, he buries himself immediately. I've been watching in my tank, as they just ooze down between the sand grains and disappear, in seconds. The next time I see them, they're climbing an eelgrass stalk, up to safety.

Bubble shell egg ribbon, on eelgrass

I have seen these egg ribbons many times, but didn't know which snails they belonged to. Now I do: I've watched the bubble shells laying them, gluing them to the eelgrass blades near the top of my tank.

There must be thousands of eggs in one ribbon, and a bubble shell will lay several ribbons over the course of a few days. Few of them survive, or we'd be wading through a mass of bubble shells. Hermit crabs love them; fish eat them, so do nudibranchs. Even in the gentle eelgrass beds, life is precarious.