Now that he was really looking around he realized there were many things about the reef that were puzzling. Some of it looked exactly like stone. He knew that it was limestone that had been built up by the coral polyps. But other portions seemed to be covered in fur. These portions were infrequent, but interesting. The covering didn’t seem to be a slime or a mold; he wasn’t sure what it was. And then, why were the swim-throughs there? They looked like gouged canyons, but there was nothing that he could see to gouge them. Did trickles of fresh water open them up? Or water or sand pouring down from the shallows to the deeps?
Furthermore, the reefs were not constant. The area with the swim-throughs, where the town was, was built up to several meters over the sandy bottom. But within a few hundred yards down the coast it had given way to scattered small rocks stuck up barely over the ground.
But even these were alive. There were delicate sea fans dangling from them, waving back and forth in the light currents. A turtle the size of a pony was lying with its belly on the sand, eating a sponge attached to the side of one of the outcroppings. There were brightly colored reef fish. There were even some larger fish that looked more of the open ocean type to him. But they had gathered around the rocks, one or at most two by each one. He thought, at first, that they were hunting something. But they were simply stopped, as much as possible, hanging motionless. When they drifted away from the rocks they would turn and come back into the current until they were over the rocks again and stop, as if they were using them as some sort of location beacon.
Intrigued he deviated from Bruce’s wake and coasted over for a closer look.
The larger fish were shaped something like tuna, but had a more rounded head, a bluish sheen and a horizontal stripe along their midline. What was happening became clear as he got close enough to see details. Smaller fish, one colored bright blue, were darting out from the rock and swimming over the body of the larger fish. He waited patiently for the larger fish to eat one of them but it never did. Instead the small fish swam all over its body, picking at it from time to time as if eating the larger fish’s skin. They even swam into its slowly opening and closing gills and as he watched in amazement one swam right into the larger fish’s mouth, poked around and came back out.
“Cleaning station,” Bruce said and Edmund realized that he had stopped instead of following his host.
“Sorry, I was just watching this,” he said.
“Good,” Bruce replied, clearly willing to dally. “I’d hoped you might actually look around you for once.”
“Was it that obvious?” Edmund chuckled.
“You’re a very focused person, Edmund Talbot,” Bruce replied. “And there are many things to focus on on the reefs. What’s happening there is that the small fish, that one’s a blue wrasse,” he said, pointing at the bright blue one, “are picking parasites off the larger fish. Which is an amberjack by the way.”
“Why doesn’t it eat them?” Edmund asked. “It seems like an easy meal.”
“Sometimes they do,” Bruce said. “But, by and large, they don’t. The small fish get the easy meal. The larger fish get their parasites picked off. If they didn’t have the small fish around, if they ate them all, they’d end up covered in parasites. Both of them get what they need; it’s what’s called a commensal relationship.”
“I saw a turtle back there eating what looked like a sponge,” Edmund said. “What does the sponge get?”
“Eaten,” Bruce replied with a shrug. “Predation is predation. But… that type of sponge grows over live coral as well as dead. If it was left unchecked it would spread over the whole reef, killing it. Tide and currents along with storms would eventually wipe the remnant coral out. So the whole ecosystem would die. If you killed all the turtles, it might not come to pass, there are other things that eat sponges and they would increase as their food source increased, but you begin to understand a small bit of the complexity of the web of life that is a coral reef. Take away the damsel fish and algae grow unchecked. Parrot fish eat the live coral, but their fecal matter is almost pure sand because of the rock they have to ingest to get to the polyps; their shit is what you see as crystal white sand. But there’s something in particular I’d like to show you; it’s not far.”
“Let’s go,” Edmund said, turning away from the cleaning station.
Down the section of patch reef a large coral head rose up in the middle of an expanse of low rocks. It was about three meters high and two across, tapering a bit like a teardrop. It was colored a faint green, as if it had some algae all over it. Sections of it were covered with the mosslike growths he’d seen elsewhere.
“This is Big Greenie,” Bruce said, coasting to a stop and letting the current carry him past the coral head. “It’s a species called green coral and it is the oldest living organism on earth.”
“I thought that was some tree in western Norau?” Edmund said, peering at the rock. “And is it alive?”
“Oh, yes,” Bruce said. “See the fuzzy patches?”
“I’d noticed them before,” Edmund admitted. “They look like it’s covered in moss.”
“Those are the live polyps,” Bruce corrected. “They’re actually related to jellyfish. Think of them as upside down jellyfish surrounded by a rock shell. They’re filter feeders; they extend tendrils that catch plankton as it passes by. Once a year they reproduce, releasing clouds of sperm and eggs to drift on the wind. But Big Greenie, here, has been doing that for seven million years.”
“Damn,” Edmund said, impressed.
“It very nearly died,” Bruce continued. “Water conditions in the mid-twenty-first century were terrible. There was, as it later turned out, a normal climactic shift to higher temperatures, then the cycle reversed and there was a sharp temperature decline, a mini-ice age. All of those created temperature stresses. Toxins released by industry into the water, divers touching the reef, industrial fishing that removed vital species, all of it nearly killed something that had lived for millions of years. There were sections of this reef where less than ten percent included live polyps; that was a recipe for disaster.”
“Your point?” Edmund said, dryly.
“You are, as I mentioned, very focused, Edmund Talbot. But while it’s important to focus on the trees, sometimes you have to let the forest speak for itself. I’m showing you the oldest tree in the forest because I thought it was something that you could focus upon. This is what the Work is all about; ensuring that the reef, Big Greenie included, is never brought to those conditions again.”
Edmund thought about that for a moment, kicking against the current to carry him back to the coral head. He dropped down to the bottom and looked at it closely, then backed up when he saw the head of a very large moray stuck back in a crevice near the coral’s base.
Finally he swam back to where Bruce was waiting patiently.
“I understand what you mean,” Talbot said.
“There’s a ‘but’ there,” Bruce replied.
“There’s a huge ‘but’ there,” Edmund admitted. “The first ‘but’ is that the conditions that you’re talking about don’t apply. Won’t apply. To get to the conditions you describe will require industry, major industry. Which cannot exist given the explosive protocols.”
“Toxins can be created without internal combustion,” Bruce said with a frown.
“Not on large scale, without internal combustion or electrical energy. The first is prevented by Mother under the explosive protocols. And any power production gets sucked up by the damned Net. So you cannot have large-scale industry. You have no idea what I’d give right now for a couple of tons of sulfuric acid, for example, but producing it in a low-tech environment is a stone bitch.”