Churn and Teem

The young fish gaped at the transformation. "Where did all of you come from?!"

Teem laughed, a sound like a million tiny bubbles. "From nothing! From sunlight and Churn's cold treasure, that's where!" She spun, and everywhere she spun, more of her bloomed. "I'm the phytoplankton — the sea's grass, the tiniest green things there are. Give me sunlight, I can make food out of it. But sunlight alone isn't enough — I need the nutrients, the buried goodness, and that stuff all sinks down into the dark where I can't reach it." She flung a bright fin at Churn. "Which is where my slow cold friend comes in. He hauls the treasure back up into my sunlight, and then — BLOOM. I turn the whole sea green with life in a matter of days."

The young fish watched, astonished, as tiny grazers — copepods, krill, larval fish — poured in to feed on Teem, and bigger fish poured in to feed on them.

"So the empty spot..." the young fish started.

"Was never empty," said Teem. "It was just waiting for the delivery."

Churn rose slow beneath the feast, watching the crowds gather, and told the young fish the part Teem was too busy to explain.

"She's the loud one," Churn said, not minding at all. "But nothing she does works without the rising. Think about it." He turned his frost-pale bulk in the current. "Up here in the light, life eats and dies, and the dead bits sink. Down and down, out of the light, out of Teem's reach — all that richness just piling up in the cold dark, useless. If it stayed down there, the surface would slowly starve. Bright, sunny, and starving."

He began his patient climb again, treasure glittering all through him.

"So the deep and the surface can't live apart. The deep is where the goodness collects. The surface is where the sunlight is. And somebody has to carry the one up to meet the other." He crested into the gold. "The wind and the spinning world do most of the pushing — but the point of it, the reason this coast teems while others sit empty, is that the deep gets a way to feed the light. Cold water rising. That's the richest thing the ocean does." He nodded up at the swirling bloom. "And then she throws a party with it."

"I throw a GREAT party," Teem called down.

"You do," Churn agreed, fond.

They came to DepthQuest together, because Marlin said the school could not have one of them without the other.

He met them at the coastal gate, where cold upwelled water met the sun. He didn't test them separately. He asked one question, to both of them at once. "Why does life crowd here, and not out in the open blue?"

Teem opened her mouth — she always went first — but this time she paused, and looked down at Churn, and waited.

Churn rose slowly into the light. "Because I bring the deep up to her," he said.

And Teem bloomed bright around him. "And I turn what he brings into a feast," she said. "Sunlight up here. Nutrients down there. Apart, we're two empty halves — cold dark water and hungry light. Together—" she swept a fin across the teeming, crowded, roaring-with-life water "—we're the reason the biggest fish runs on the whole planet happen right on cold coasts like this one."

Marlin looked at the two of them, the slow cold riser and the bright loud bloom, one impossible without the other. "You can't be graded apart," he said. "You belong here. Both of you. Especially both of you."