The Empty Forest

The water in the cove was so clear you could see straight to the bottom, and the bottom was nothing.

"Look at this," Maya said. She was lying flat on the wet rock with her face over the edge. "It's like a parking lot down there."

Soren got down beside her. Below them the seafloor went on grey and bare, scattered with round purple lumps packed shoulder to shoulder. Spiny. Hundreds of them. Not a single green thing growing anywhere.

"Sea urchins," Soren said. "That's a lot of sea urchins."

"Last year there was kelp here," Maya said. "Big kelp. Like a forest. We swam through it, remember? It was so thick you couldn't see your own feet."

"I remember a fish bit my shoelace."

"That's the one." She frowned at the water. "Where did the forest go?"

Soren counted urchins for a while, lost his place, and started again. "There's way more urchins than last year. Maybe they ate it."

"Urchins eat kelp?"

"They scrape it. Off the rock. My uncle's a diver, he calls a place like this an urchin barren." Soren sat up. "But there were urchins last year too. And there was still a forest. So what changed?"

Maya didn't answer. She was watching the far rocks, where the swell broke white. Then she said, "There were otters last year."

Soren looked.

"Right there," she said, pointing. "By the kelp. There were always two of them floating on their backs. Cracking things on their stomachs. We watched them for an hour and you said your hands were cold."

"They're not there now."

"No." Maya sat up too. "And the forest's not there now."

Soren pulled out his notebook and drew a line of urchins, then a question mark above them. He chewed the pen. "Okay. But otters don't eat kelp. So how would otters losing change the kelp?"

"What do otters eat?"

He stopped chewing. "Urchins. My uncle said. They crack them open."

They looked at each other.

"So," Maya said slowly, "the otters weren't there for the kelp. They were there for the urchins."

"And the urchins are there for the kelp."

"And when the otters go away," Maya said, and her voice sped up, "nothing's eating the urchins, so the urchins go crazy, so they eat the whole forest."

"Wait, wait." Soren held up a hand. He wasn't disagreeing. He just needed it in order. "Run it backward. Last year. Otters eat urchins. So there's only a few urchins. So the few urchins can't keep up with the kelp. So the kelp wins, and it grows into a forest."

"And the fish live in the forest. And the crabs. And the thing that bit your shoelace."

"And the snails. And the little ones we never figured out." Soren was writing fast now. "Maya. The forest wasn't keeping the fish alive. The otters were keeping the fish alive. By eating something that the fish never even touch."

They both went quiet and looked at the empty grey floor.

"That's the part that's weird," Maya said. "The otters aren't even the biggest thing here. The kelp's the biggest thing. The kelp's the whole forest. And the kelp lives or dies because of an animal small enough to float on its back."

Soren stared at his question mark. "Take out one animal. Not even a big one. And everything falls down."

"Like that game with the wooden blocks," Maya said. "Where there's one block holding up the whole tower and you don't know which one until you pull it."

"Except you can't see which block it is by looking. The otter doesn't look important. It looks like it's just floating around being cute."

Maya laughed, but it was a small laugh, because she was still looking at the urchins.

"There were two of them," she said. "Just two otters. And two otters were the difference between this and a whole forest."

A wave came up the rock and soaked their knees and neither of them moved.

"So where did the otters go?" Soren asked.

"I don't know." Maya pulled her knees up. "Maybe they swam somewhere. Maybe something happened to them. My mom would know who to ask."

"If somebody put otters back," Soren said carefully, "the otters would eat the urchins, and then the kelp could grow again, and then the fish would come back. The whole forest. From otters."

"You could rebuild a forest by adding one animal." Maya turned to him. "That's the same weird thing backward. One small animal builds the whole thing."

Soren wrote that down. Then he stopped writing and looked at the cove the way you look at a room when the furniture has been moved.

"I keep thinking the big stuff matters most," he said. "The forest. The kelp. The thing you can see from up here. But it's never the big stuff. It's the thing nobody's looking at."

"The thing floating on its back," Maya said.

"The thing that doesn't look important."

They sat with that. Out past the white water there was nothing on the surface, no dark head, no flat floating shape cracking something on its stomach. Just swell, and the grey light, and underneath it a forest that wasn't there anymore because two animals weren't there anymore.

"Maya," Soren said. "How many other places are like this? Where one little thing is holding up everything, and nobody knows which little thing it is?"

"Probably all of them." She said it quietly. "Probably every place is one animal away from being a parking lot. And we don't even know which animal until it's gone."

Neither of them said anything after that. Soren held the open notebook on his knees and the page got speckled dark where the spray reached it.

Far out, a single dark shape rolled up onto the surface, turned onto its back, and lay there a moment against the grey before the swell hid it again.

Maya grabbed Soren's arm and pointed, and they both stopped breathing, waiting for it to come up once more.