At one end of a long row of displays in the Steinhart Aquarium in
San Francisco, a concentrated coral reef sits happily tucked under
lights. The Aquarium's self-contained South Pacific ocean compresses the
distributed life in a mile-long underwater reef into a few glorious
yards behind glass.
The condensed reef's extraordinary hues and alien life forms cast a New
Age vibe. To stand in front of this rectangular bottle is to stand on a
harmonic node. Here are more varieties of living creatures crammed into
a square meter than anywhere else on the planet. Life does not get any
denser. The remarkable natural richness of the coral reef has been
squeezed further into the hyper-natural richness of a synthetic
A pair of wide plate glass windows peer into an Alician wonderland of
exotic beings. Fish in hippie day-glo colors stare back-accents of
orange- and white-banded clown fish or a minischool of iridescent
turquoise damsels. The flamboyant creatures scoot between the feathery
wands of chestnut-tinted soft corals or weave between the slowly
pulsating fat lips of giant sea clams.
No mere holding pen, this is home for these creatures. They will eat,
sleep, fight, and breed among each other, forever if they can. Given
enough time, they will coevolve toward a shared destiny. Theirs is a
true living community.
Behind the coral display tank, a clanking army of pumps, pipes, and
gizmos vibrate on electric energy to support the toy reef's
ultradiversity. A visitor treks to the pumps from the darkened viewing
room of the aquarium by opening an unmarked door. Blinding E.T.-like
light gushes out of the first crack. Inside, the white-washed room
suffocates in warm moisture and stark brightness. An overhead rack of
hot metal halide lamps pumps out 15 hours of tropical sun per day.
Saltwater surges through a bulky 4-ton concrete tub of wet sand brimming
with cleansing bacteria. Under the artificial sunlights, long, shallow
plastic trays full of green algae thrive filtering out the natural
toxins from the reef water.
Industrial plumbing fixtures are the surrogate Pacific for the reef.
Sixteen thousand gallons of reconstituted ocean water swirl through the
bionic system to provide the same filtration, turbulence, oxygen, and
buffering that the miles of South Pacific algae gardens and sand beaches
perform for a wild reef. The whole wired show is a delicate, hard-won
balance requiring daily energy and attention. One wrong move and the
reef could unravel in a day.
As the ancients knew, what can unravel in a day may take years or
centuries to build. Before the Steinhart coral reef was constructed, no
one was sure if a coral reef community could be assembled artificially,
or how long it would take if it could. Marine scientists were pretty
sure a coral reef, like any complex ecosystem, must be assembled in the
correct order. But no one knew what that order was. Marine biologist
Lloyd Gomez certainly didn't know when he first started puttering around
in the dank basement of the Academy's aquarium building. Gomez mixed
buckets of microorganisms together in large plastic trays, gradually
adding species in different sequences in hopes of attaining a stable
community. He built mostly failures.
He began each trial by culturing a thick pea-green soup of algae -- the
scum of a pond out of whack -- directly under the bank of noon-lights. If
the system started to drift away from the requirements of a coral reef,
Gomez would flush the trays. Within a year, he eventually got the
proto-reef soup headed in the right direction.
It takes time to make nature. Five years after Gomez launched the coral
reef, it is only now configuring itself into self-sustenance. Until
recently Gomez had to feed the fish and invertebrates dwelling on the
synthetic reef with supplemental food. But now he thinks the reef has
matured. "After five years of constant babying, I have a full food web
in my tank so I no longer have to feed them anything." Except sunlight,
which pours on the artificial reef in a steady burst of halide energy.
Sunlight feeds the algae which feed the animals which feed the corals,
sponges, clams, and fish. Ultimately this reef runs on electricity.
Gomez predicts further shifts as the reef community settles into its
own. "I expect to see major changes until it is ten years old. That's
when the reef fusing takes place. The footing corals start to anchor
down on the loose rocks, and the subterranean sponges burrow underneath.
It all combines into one large mass of animal life." A living rock grown
from a few seed organisms.
Much to everyone's surprise, about 90 percent of the organisms that fuse
the toy reef were stowaways that did not appear to be present in the
original soup. A sparse but completely invisible population of the
microbes were present, but not until five years down the road, when the
reef had prepared itself to be fused, were the conditions right for the
blossoming of the fuser microorganisms which had been floating unseen
During the same time, certain species dominating the initial reef
disappeared. Gomez says, "I was not expecting that. It startled me.
Organisms were dying off. I asked myself what did I do wrong? It turns
out that I didn't do anything wrong. That's just the community cycle.
Heavy populations of microalgae need to be present at first. Then within
ten months, they've gone. Later, some initially abundant sponges
disappeared, and another type popped up. Just recently a black sponge
has taken up in the reef. I have no idea where it came from." As in the
restorations of Packard's prairie and Wingate's Nonsuch Island,
chaperone species were needed to assemble a coral but not to maintain
it. Parts of the reef were "thumbs."
Lloyd Gomez's reef-building skills are in big demand at night school.
Coral reefs are the latest challenge for obsessive hobbyists, who sign
up to learn how to reduce oceanic monuments to 100 gallons. Miniature
saltwater systems shrink miles of life into a large aquarium, plus
paraphernalia. That's dosing pumps, halide lights, ozone reactors,
molecular absorption filters, and so on, at a cool $15,000 per living
room tank. The expensive equipment acts like the greater ocean,
cleaning, filtering the reef's water. Corals demand a delicate balance
of dissolved gases, trace chemicals, pH, microorganisms, light, wave
action, temperature -- all of which are provided in an aquarium by an
interconnected network of mechanical devices and biological agents. The
common failure, Gomez says, is trying to stuff more species of life into
the habitat than the system can carry, or not introducing them in the
correct sequence, as Pimm and Drake discovered. How critical is the
ordering? Gomez: "As critical as death."
The key to stabilizing a coral reef seemed to be getting the initial
microbial matrix right. Clair Folsome, a microbiologist working at the
University of Hawaii, had concluded from his own work with microbial
soups in jars that "the foundation for stable closed ecologies of all
types is basically a microbial one." He felt that microbes were
responsible for "closing the bio-elemental loops" -- the flows of
atmosphere and nutrients -- in any ecology. He found his evidence in random
mixtures of microbes, similar to the experiments of Pimm and Drake,
except that Folsome sealed the lid of the jars. Rather than model a tiny
slice of life on Earth, Folsome modeled a self-contained self-recycling
whole Earth. All matter on Earth is recycled (except for the
insignificant escape of a trace of light gases and the fractional influx
of meteorites). In system-science terms, we say Earth is materially
closed. The Earth is also energetically/informationally open: sunlight
pours in, and information comes and goes. Like Earth, Folsome's jars
were materially closed, energetically open. He scooped up samples of
brackish microbes from the bays of the Hawaiian Islands and funneled
them into one- or two-liter laboratory glass flasks. Then he sealed them
airtight and, by extracting microscopic amounts from a sampling port,
measured their species ratios and energy flow until they stabilized.
Just as Pimm was stunned to find how readily random mixtures settled
into self-organizing ecosystems, Folsome was surprised to see that even
the extra challenge of generating closed nutrient recycling loops in a
sealed flask didn't deter simple microbial societies from finding an
equilibrium. Folsome said that he and another researcher, Joe Hanson,
realized in the fall of 1983 that closed ecosystems "having even modest
species-diversity, rarely if ever fail." By that time some of Folsome's
original flasks had been living for 15 years. The oldest one, thrown
together and sealed in 1968, is now 25 years old. No air, food, or
nutrients have ever been added. Yet this and all of his other jar
communities are still flourishing years later under florescent room
No matter how long they lived, though, the bottled systems required an
initial staging period, a time of fluctuation and precarious instability
lasting between 60 and 100 days, when anything might happen. Gomez saw
this in his coral microbes: the beginnings of complexity are rooted in
chaos. But if a complex system is able to find a common balance after a
period of give and take, thereafter not much will derail it.
How long can such closed complexity run? Folsome said his initial
interest in making materially closed worlds was sparked by a legend that
the Paris National Museum displayed a cactus sealed in a glass jar in
1895. He couldn't verify its existence, but it was claimed to be covered
with recurrent blooms of algae and lichens that have cycled through a
progression of colors from shades of green to hues of yellow for the
past century. If the sealed jar had light and a steady temperature,
there was theoretically no reason why the lichens couldn't live until
the sun dies.
Folsome's sealed microbial miniworlds had their own living rhythms that
mirrored our planet's. They recycled their carbon, from CO2 to organic
matter and back again, in about two years. They maintained biological
productivity rates similar to outside ecosystems. They produced stable
oxygen levels slightly higher than on Earth. They registered energy
efficiencies similar to larger ecosystems. And they maintained
populations of organisms apparently indefinitely.
From his flask worlds, Folsome concluded that it was microbes -- tiny
celled microbits of life, and not redwoods, crickets, orangutans -- which
do the lion's share of breathing, generating air, and ultimately
supporting the indefinite populations of other noticeable organisms on
Earth. An invisible substrate of microbial life steers the course of
life's whole and welds together the different nutrient loops. The
organisms that catch our eye and demand our attention, Folsome
suspected, were mere ornate, decorative placeholdings as far as the
atmosphere was concerned. It was the microbes in the guts in mammals and
the microbes that clung to tree roots that made trees and mammals
valuable in closed systems, including our planet.