As oceans change faster than species can, scientists at Arizona’s Biosphere 2 set evolution to hyper-speed
Photos and Story by Hannah Hindley
In a massive simulated ocean in the middle of the Sonoran Desert, life creeps by at the pace of a hermit crab. Or, rather, 10,000 hermit crabs. The 676,000-gallon tank — once a thriving marine ecosystem enclosed within Biosphere 2 back when the research facility was sealed off from the outside world in the early 1990s — has ebbed into disuse in recent years.
Originally, Biosphere 2 was built as a demonstration of a complex closed ecological system — one that could support human life on this planet and possibly on others. The model ocean housed an elaborate coral reef, but as scientists began manipulating carbon dioxide levels, the health of the ocean deteriorated and it was left to turn brackish with neglect.
The glass-walled facility still serves as a model of our Earth in miniature. A fog desert, mangrove marsh, savanna grassland and tropical rainforest still flourish under the glass ceiling, and more than 3 acres of pumps and pipes whir in the dripping basement, controlling humidity levels and moderating temperatures for the tangled world that lives and breathes above ground.
But the Ocean dozes nearby. A slow current shuffles against the beach. No reefs bloom with life. The salinity lags well below average ocean levels, and only a handful of hardy yellow tang — fish that have survived since the early days — mill below the surface.
Recently, though, thousands of hermit crabs were set free to graze down the algae in the brackish ocean water, and oysters nearshore are slowly filtering some of the haze out of the tank. Quietly and in small degrees, scientists are preparing the neglected tank for what may well become one of the most pivotal and contentious projects of this century: to find the genetic key to saving our oceans’ dying coral reefs.
The immortal organism
Most corals begin their lives adrift at sea. Tiny oval-shaped planulae — living larvae — are carried in the lap of the ocean, lifting and drifting, reaching toward the light. These little wanderers might ride currents for two days, or two weeks, or two months before they turn from the surface and swim toward the sea floor. There, they transform from planula into polyps. Their soft bodies change shape. Star-like tentacles and ruffled digestive filaments materialize like blooming flowers. Each polyp secretes a hard foundation for itself, and as the polyps grow, that foundation grows upward in segments, too. It is as if the living polyps are slowly constructing castles for themselves, stone by stone. The castles — huge reef systems slowly built by individual polyps out of bony calcium carbonate — can be thousands of years old. They stack up like ramparts along the edges of continents, they encompass islands, and when the islands erode back into the sea, the walls of coral remain after the last of the land is gone.
More than 93 percent of the reef — the world’s largest living structure — had been damaged in by coral bleaching when the obituary came out, but dead and dying “are two very different things,” ~ Chris D’Angelo, science writer
Not all corals reproduce with planula; some simply clone themselves. They split in half, and in half again, creating genetic copies of themselves in a rebirthing process that can last for centuries. While an individual polyp might live for only two years, some scientists argue that the clonal nature of corals brings them as close to immortality as any earthly organism can get.
Immortality? It came as an ugly surprise, then, when in October 2016 an obituary was published for Australia’s Great Barrier Reef, a coral system so huge that it can be seen from outer space.
“The Great Barrier Reef of Australia passed away in 2016 after a long illness,” Outside Magazine posted. “It was 25 million years old.”
The obituary, it turns out, was an alarmist article published prematurely. Scientists clamored to refute the claim. More than 93 percent of the reef — the world’s largest living structure — had been damaged in by coral bleaching when the obituary came out, but dead and dying “are two very different things,” said science writer Chris D’Angelo in a Huffington Post article.
We’re quickly learning, though, that the distance between “dead” and “dying” might be shrinking too quickly for the world’s corals to keep up. D’Angelo used a human metaphor to quell the frenzy stirred up by the Great Barrier Reef obituary: If “a person is diagnosed with a life-threatening illness, their loved ones don’t rush to write an obituary and plan a funeral.”
In a recent conference at the University of Arizona’s Biosphere 2, scientists decided not to rush the funeral. Instead, they hope to shuttle sickened corals into the equivalent of Urgent Care.
Under the sea, an emergency
Corals are dying off around the world. The causes are complicated, but what’s clear is that the death toll is accelerating as the ocean continues to warm. In warming water, corals get stressed and “cough up” little symbiotic algae called zooxanthellae that usually live within corals’ tissues, photosynthesizing and producing vital energy for their host. Zooxanthellae give corals their brilliant colors, so when they’re purged, it’s the equivalent of leaves losing their chlorophyll in the autumn: The color underneath shines through. In the case of corals, that color is white: This is called coral bleaching.
Bleaching events don’t necessarily kill corals. If conditions return to a more comfortable temperature, zooxanthellae will repopulate their coral hosts. More often, though, says Dr. Ruth Gates, director of the Hawaii Institute of Marine Biology (owned by University of Hawaii at Manoa), a coral bleaching event will leave the majority of corals dead. “As climate change intensifies, things get more frequently stressful,” and “more and more corals die,” Gates says. “The intrinsic capacity of the system to keep up has been overwhelmed.”
Why does that matter to us? “We’ve caused it, but we’re also going to be affected by it,” says Katie Morgan, program coordinator for Marine Science Education and Outreach at Biosphere 2. Coral reefs support communities around the world, as tourism hubs, as food sources and as surge protection from increasingly intense storm systems worldwide. If we lose coral, we “don’t have these essential things that we need on a daily basis to do so many vital things for the Earth and for humans,” Morgan says. The emergency at hand is not just that corals are dying — it’s that our own lives are wrapped up inextricably with the fate of corals.
Can corals rebound from these changes on their own? Maybe: “Biology does cool things, you never know,” Morgan says.
However, it is the speed of change that spells disaster for corals and for so many other animals in the midst of what many scientists are calling the Sixth Great Extinction. The ocean, Morgan says, is “getting warmer at a rapid rate, more rapid than we ever could have predicted.” Gates predicts that with no action, “the majority [of corals] will be dead by 2050. That’s only 33 years away.”
This sobering vision lends a sense of urgency. If we simply sit back and watch, within our lifetime we may well be witnessing the end of oceans as we know them.
Ocean urgent care
The solution? Well, “What we really need to address are the greenhouse gases,” Morgan says. “As human beings, if we want these environments to exist, we’ve got to start addressing that on a bigger level.”
It is clear, though, that if we wait for change to come on political and large-scale societal levels, corals will already be long gone. Instead, scientists at Biosphere 2 are getting ready to intervene in a swift and action-based manner. The intention: To selectively breed super-powered corals that will be resistant to damages from climate change.
Early in October 2017, Biosphere 2 hosted a conference to determine how best to use the Ocean at the facility as a testing ground for saving corals in any way possible. The project will likely involve “breeding the hardiest of the hardy together,” says Gates, “developing corals that can survive the future, by potentially accelerating natural selection.” This is “assisted evolution,” and while it has its critics, the goal is to give corals the best chance of survivorship in an increasingly inhospitable sea.
The project will necessitate cleaning up the preexisting Ocean tank at Biosphere 2, rapidly growing a complex coral reef system within it using what Gates called “extraordinary performers” — the most robust corals that can be bred — and then pushing the temperature of the entire system in order to determine if these corals can survive in the conditions that are predicted for oceans in the coming years. Although coastal communities around the world claim to have their own unique strains of tough corals, the scientists at Biosphere 2 aren’t limiting their project to the easy or the obvious — they’re open to underdogs and surprises. Corals can be “robust” in diverse ways. What biologists do suspect, says Gates, is that there are certain groups of genes that are responsible for many kinds of stress responses in corals. If researchers can pinpoint those genes, they might be able to find the key to coral survivorship in an ocean that faces many extreme changes beyond rising temperature alone.
The early stages of this process might be messy — this is a bold move toward applied science rather than a methodical experiment, Morgan clarifies. The pacing will reflect this. A team of scientists from across many disciplines will be coming together, and the details will likely come into focus only after the project is already underway.
There is an urgency to saving coral reef systems that does not allow for tidy pre-planning. “We might not have our entire feet on the ground,” Morgan says, but “the race against time is huge, and that’s probably what scares me the most. If we don’t do it, … we’re losing an incredibly important ecosystem.”
And although we strive for orderliness in science, Dr. Kevin Bonine, director of Education and Outreach at Biosphere 2, reminds us that science should really be less about formulas and more about “open-ended questions, creativity.” Risk-taking and creative problem-solving drive scientific discovery in all fields.
This is an ambitious project with a tight timeline and no certainty of success, and that’s what makes it “tantalizingly exciting,” says Gates. “We don’t know whether we will succeed…. The best you can ask from yourself is to try something and not be tied to the result.”
Morgan lays out the stakes in clear terms. “We have two options — to do it or not to do it. And if we do it, and we go forward and we ask these questions and we take the risks and we establish a solution that can help mitigate the problem, great,” she says. “If we don’t, we don’t have corals.”
“This is the place where unusual things can be done,” ~ Ruth Gates, director of the Hawaii Institute of Marine Biology
Bridge over troubled waters
Ecologists tend to be leery of human interference in natural processes. We devise creative solutions for rebalancing imperiled ecosystems, but often our interventions have unforeseen ramifications. Consider the mongoose.
As human development and activity push wildlife populations to the edge, we continue to come up with hands-on approaches to righting our wrongs: assisted migration, assisted breeding, assisted predation and now, in the case of corals, assisted evolution. Gates acknowledges that her experiments in coral breeding have met with resistance, from dubiousness about the ability to fabricate a complex coral system (“You might be able to plant a garden, but you can’t build a reef”) to fearful speculation about genetic modification (“Oh, it’s Monsanto for the corals”). Of naysayers, Gates says, “They’re concerned about maybe you’re going to introduce an invasive that’s going to somehow overgrow the natives, or maybe you’re going to manipulate something that’s going to have very, very serious downstream consequences.”
All these concerns are valid. This is where Biosphere 2 rises out of the fabric of contention.
When Gates was first approached to help in the strategic planning for the Biosphere 2 Ocean, she remembered thinking: “If it was up to me, I’d take these criticisms of our work and … address them in this extremely safe environment.”
Biosphere 2 makes for a matchless demonstration site. It is an ocean in the middle of the desert. “There’s no natural reef there. There’s nothing to contaminate or invade,” Gates says.
What better testing ground? “This is the place where unusual things can be done,” Gates says. Here, “you can test things at the extreme end of the intervention portfolio … because there’s no risk to it.”
In addition to serving as a large-scale demonstration model, the Ocean at Biosphere 2 also serves as an intriguing middle ground along the spectrum of experimental and applied science. The tank is certainly more complex than an average lab setting. In place of test tubes and shelves of small aquaria, Biosphere 2’s Ocean has circulating currents and space for ecosystems to develop outside of the human grasp (take, for example, the populations of yellow tang that have survived — and possibly bred — in their own hazy corners of the neglected Ocean, unbidden and overlooked).
The Ocean tank at Biosphere 2 is a far cry from the real sea, though. Not only is it hemmed in by walls and regulated by filters and bags of salt labeled “Instant Ocean,” but the interconnected coral ecosystem that scientists will introduce into the tank can’t come close to the elaborate and often unseen web of life that interlaces the world’s wild reef systems. That is to say, any study done in Biosphere 2’s Ocean isn’t — quite — a “field study.” But it comes close. Biosphere 2 provides a unique link between a conventional small-scale lab experiment and an ecosystem-wide field study. The ocean at Biosphere 2 is, in essence, a model. “Models are important,” Morgan says, “because we get to do what we’re scared to do in nature.”
The consensus is, there is no comparable — and no better — place for an experiment of this scale to take place. It may look like a space dome, but Biosphere 2 is built perfectly to be a bridge — between lab and sea, between fear and fact.
“Everything in this design is about many voices, not one,”
~ Ruth Gates, director of the Hawaii Institute of Marine Biology
Partner dance
If you sit down with Gates and ask her why she loves corals, she’ll talk about big-picture stuff. She’s fascinated by symbiosis — beneficial partnerships between wildly different organisms — from “the scale of the cell all the way up to the way that we interact with our planet.” Few other animals can house plant cells the way that corals do, and Gates imagines that this same stunning convergence of differences might seep into the planning process at Biosphere 2. At its heart, the project is collaborative. It will necessitate creative thought across diverse disciplines. It will likely require both boldness and compromise. As scientists from different institutions and different backgrounds work together — symbiotically, one might say — they will need to be as flexible and adaptive as the coral reefs they hope to breed, Gates says. “Everything in this design is about many voices, not one.”
That collaboration extends beyond the glass walls of Biosphere 2. Gates runs her own coral-breeding lab on a 28-acre island in the middle of Kāneʻohe Bay, O’ahu. Farther south, Australia’s $37 million National Sea Simulator breeds corals in a finely regulated enclosed environment. In Hawaii’s setting a true living coral reef can be monitored, tested and manipulated; in the latter, corals can be bred in a sophisticated indoor aquarium where everything from water acidity to sediment content can be controlled. As a large-scale and isolated demonstration site, says Gates, Biosphere 2 “is the third unique partner in that triumvirate.”
But, Gates adds, there’s a fourth partner, too, which is “every reef everywhere in the world.” After all, applied science eventually necessitates bringing carefully formulated findings into a real-world setting. If demonstrations at Biosphere 2 go well, the ultimate test — the one that dictates doom or survival of reefs worldwide — will have to written on the pages of the living sea.
In the middle of the desert, an ocean waters seeds of hope
And so it begins — the race to save corals while there are still corals to be saved. Sixty thousand pounds of salt have already been poured — one 15-pound bag at a time — into Biosphere 2’s Ocean to return it to the proper salinity. Hermit crabs with bright red legs scrape industriously at the tank’s green slick of algae, and sophisticated filters will soon be purifying the water in preparation for a coral reef to bloom beneath the glassy sky. It is a strange vision: an ocean coming to life in the middle of the desert. But “we cannot do this anywhere else,” Morgan says.
As the degraded marine environment at Biosphere 2 emerges, phoenix-like, from its ash-like algal haze, it offers hope of a different variety than its initial purpose dished up. Critics of Biosphere 2’s original mission in the 1990s worried that researchers were looking to re-create livable conditions in a way that could be transferable to colonization projects on other planets. Now, scientists will be looking inward. How can we give back to our own planet? How can we learn more deeply about Earth’s systems by attempting to imitate and enhance them? How can we preserve what we’ve damaged before it’s gone?
Certain biological mechanisms seem too complex, too delicate for the human hand. Arguably, in a well-balanced world, evolution would be among those untouchable systems. But although it is no longer sealed off from the outside world as a self-sustaining experiment in replicating Earth’s systems, Biosphere 2 might finally be drawing closer than ever to becoming a true scale model of living, changing, fragile planetary processes. Under that glass dome, in an ocean far from the nearest real sea, selection — natural or otherwise — is about to get a head start in a wildly shifting world.
