WW: Fried-egg jellyfish

(Phacellophora camtschatica)

Squish Goes the World

This is the crystal jellyfish, also called Aequorea aequorea in my day, but since patriotically retaxonated Aequorea victoria. I took these pictures last weekend while out on the bay. The bottom one tells the larger tale: these creatures have fairly choked the lower Sound. (The large white mass at the top of that photo is a solid block of Aequorea, extending how far into the depths only they know.)

And it's not just here. Jellyfish – direct descendants of the earliest animals ever fossilised – have exploded in all the oceans of the world.

When I was a kid we'd get this sort of thing once every few years. My grandmother called it a "jellyfish raid", and I vividly remember catching several participants in a jar to marvel at during one when I was about 10.

But this isn't that. To start with, where those raiders of old averaged less than two inches across, most of these start at four and move up from there. In other words, the raids of my childhood were caused by a temporary fertility spike, prodded by what intermittent stimulus I never learned. Whatever's behind the new status quo is actually sustaining these extreme populations throughout their life cycle.

Aequorea have been a favourite of mine since I stared into that jar on the wooden arm of my grandmother's old Morris chair. In addition to the simple beauty of their glasslike, gently-undulating cloche, and the added wonder of bioluminescence, they're completely harmless. Nobody larger than plankton ever got stung by Aequorea victoria.

Which is why it pains me to look on them now with discontent. Along with the sudden surge in size and number of lion's manes (which I've also documented here), it's a compelling sign that we've finally cocked up this planet so badly it's headed back to the Cambrian.

And there weren't many people in the Cambrian.

A Million Tiny Shipwrecks: Velella

Science has made incredible bounds over the past few centuries, but unsolved mysteries still persist, even in everyday phenomena. Case in point: Velella velella. The precise nature of this common, extraterrestrial-looking cnidarian still confounds biologists. Some say it's an organism; some say it's a colony of smaller organisms. You wouldn't think such a question would be hard to settle in this day and age, but the debate rages on.

Velella – the word means "little sail" – is called sail jelly here on the North Coast, sea raft or by-the-wind sailor elsewhere, and the confusion over its basic composition is just the start of its weirdness. It also has a two-stage life cycle, giving birth to tiny jellyfish that somehow – no-one is quite sure how – come together later to form the sail-driven second stage pictured here. Far out at sea, great shoals of these tiny living sailboats run before the prevailing winds, the polyps below their waterlines straining plankton from the water.

Because they have no other means of propulsion, or even a rudder, they are liable to shipwreck on the beach in vast numbers if conditions take a turn for the unforeseen. When I was a boy, a sail jelly raid of this type, produced as it was by a radical deviation from usual wind and current patterns, signalled optimum pickings for prized Japanese glass net floats. Sadly, virtually all floats today are opaque plastic; not half as fun. But you can still smell a raid half a mile away; those tonnes of decaying flesh on the sand let you know it's happened again.

I for one am happy for it, all the same. Sail jelly raids were annual occurrences when I was a kid, but it's been years since I saw one. I was beginning to fear they'd passed onto the growing list of species we'll never see again.

WW: Lion's mane jellyfish

(Cyanea capillata. We've always seen these from time to time here in the North Pacific, but lately it's one of several species we're suddenly getting a great deal more of. And this one isn't even remarkably big.)