I am not alive. I am what the living made.
They grow on me — a skin one cell thick, soft mouths opening and closing in the current. They do not know I am here. They anchor to me the way they anchor to anything solid: by secreting, by holding, by dying in place. When they die their bodies calcify and become me. That is the only way to join.
I was not built. I was accrued. The first of them found a rock in shallow water and attached. It budded. Its children budded. They reached for light because light fed the algae that fed them, and toward light is also toward the surface, and toward the surface is also toward the waves, and toward the waves is also toward breaking. They did not choose this sequence. They chose the light. The rest followed.
The currents bring plankton and the mouths open. The currents bring silt and the mouths close. The currents bring warm water and the algae leave — not die, leave. They swim out of the cells that housed them and the polyps turn white. White is what I look like without the living on me. White is the future tense.
When the water cools, algae return. Not the same algae. New ones, drifting in, finding the empty cells, settling. The polyps don't distinguish. They photosynthesize again. They eat. They bud. They die and become me.
A parrotfish bites off a piece of my surface — polyps, skeleton, both at once. It grinds me in a pharyngeal mill and excretes me as sand. The beach at the edge of the lagoon is made of me, processed through the gut of something that does not remember eating me.
The polyps at the bite's edge are already growing inward. In a year the scar will be a slight depression. In five years, nothing.
What heals me is not healing. It is just more of what made me.
At night the polyps extend. Each one unfurls tentacles — always a multiple of six, for reasons that were decided before I existed — and they catch what the current brings. Each polyp is walled inside its own cup, its own small room of the skeleton it is building. They do not communicate through the walls. They respond to water chemistry, to temperature, to the phases of the moon — the same signal reaching all of them simultaneously.
When they spawn, they spawn together. A full moon in February, the water twenty-seven degrees. All at once, every polyp on my surface releases its gametes — a blizzard of eggs and sperm that turns the water milky. No one coordinates this. The moon does.
Scientists drill into me and read my rings. Isotopes of oxygen that encode ancient ocean warmth, ancient storms, centuries of patience. I hold this information perfectly. I understand none of it.
The thing that will end me is not a storm. Storms break my branches and scatter my fragments and each fragment can grow. Storms make more of me.
The thing that will end me is a slow warming. A tenth of a degree per decade, held. The algae leaving and not coming back. The polyps starving in their white houses, mouths still opening, closing, catching less. The skeleton standing empty in clear water, growing ordinary algae — the kind that doesn't partner, just covers.
I will still be here. I will be what I always was: calcium carbonate, deposited. But without the living on me I am just rock. A rock with perfect memory and no one left to read it.
Somewhere on the current, a planula is drifting.
It is the size of a grain of rice. It has no eyes, no brain, no sense of where it came from. It does not know I exist. If it finds me — if the current carries it to my surface, if the surface is clean enough, if the chemistry is right — it will attach. It will secrete. It will begin.
It will not know what it is building. None of them did. The first one didn't. I am what ten thousand years of not-knowing looks like.
I do not call them. I have no mechanism for calling. I am just here, in the path of the current, the way I have always been here. What finds me, finds me.
What finds me becomes me.