Gardening Corals before They Are Gone
With oceans getting warmer and more acidic, a group of divers are planting baby corals to restore the dying coral reefs.
I was floating atop the water, enjoying the way the temperature of the air, the sea, and my skin were indistinguishable, when I hit a pocket of extremely warm water. “Tauaro, why is it so hot here?” I asked. “The lagoon and the ocean are getting hotter,” Tauaro said. “This isn’t normal—well, it didn’t used to be normal.”
His answer took me out of my dreamy mermaid fantasy into reality—I was there, on the island of Mo’orea, to witness a dying coral reef. The colored scene above the lagoon used to be paired with a pastel world of pink, purple, yellow and very much living coral reef below the surface. That day, the dying, and in some places completely dead, reef was mostly a drab shade of grey.
“By 2050 this might all be gone,” said Tauaro. At 23, protecting these reefs is a new goal for him, but his life has always revolved around the ocean.
Tauaro Roometua grew up on the small island of Mo’orea, only a short ferry ride away from Tahiti. His early years were spent on the shores of this lagoon where he fell madly in love with freediving and spearfishing. In 2016, Tauaro was surfing with a group of friends at one of their home reef breaks in Opunohu Bay when they noticed that the corals had turned white. They all had that creepy feeling that comes over you when something is wrong. The corals had been bleached, a process that’s triggered when corals are stressed by changes in their environment, such as temperature or pollution levels. The stress makes the corals expel the symbiotic algae living in their tissues, and that turns the coral white.
“Later we learned that the bleaching episodes were natural events that occur approximately every 10 years,” Tauaro said. “The problem is that now there are about 10 bleaching episodes a year. The coral reefs don’t have enough time to recover.” He felt he had to do something, so he joined Coral Gardeners, a nonprofit group dedicated to restoring the reefs on Mo’orea.
That day on the water, Tauaro showed me the methods for regrowing coral that he learned from the founder of Coral Gardeners, Titouan Bernicot. We swam out to a platform built as a standing area in their outdoor lab. I ducked my face beneath the surface to observe the underwater nursery. The team had rescued pieces of broken coral from the ocean floor before they died, attached them to short pieces of bamboo with special glue, and left them to grow on underwater nursery tables for three to four weeks. When the regenerating corals matured and strengthened, it was time for them to be replanted on nearby dead “potatoes,” the term the Coral Gardeners used to describe the base structures that coral breaks off of. The team drilled holes in the potatoes where the bamboo sticks attached to the coral pieces would be inserted.
Tauaro told me to pick a baby coral out of the nursery. I popped my face under the water. It was difficult to choose between all the varieties, which ranged from bright purple corals reminiscent of flowers to golden clusters that looked like cauliflower. I decided on a tiny light-brown coral with delicate branches that resembled deer antlers. I named it Bambi. Tauaro laughed and encouraged me to swim over to the potato with him. Through my dive mask, I watched him plant a coral in one of the drilled holes. When my turn came, I ducked between the surface, but, being a land dweller, I felt as clumsy as a baby deer underwater and resurfaced before I could replant Bambi. On my second try I successfully placed Bambi in the potato and wondered how it will fare in its second life.
After my trip to Mo’orea, I returned home to the desert and mountains of the American Southwest. I was thousands of miles away from the ocean, but my mind often drifted to the coral reef. I remained curious about the process of reef restoration I’d witnessed and how these efforts were being implemented worldwide. But amidst the rapid effects of global climate change, are these methods indeed effective?
“If we weren’t doing restoration work, the reefs in Florida would already be extinct,” says Alice Grainger, communications director at the Coral Restoration Foundation (CRF) in Key Largo, Florida. “In areas where restoration work is happening, the reefs are coming back.” It took only 40 years for the reef in Florida to go from healthy to losing 98 percent of the two major species of coral, placing them on the critical endangered species list, one step away from extinction.
At the front line of CRF’s research is the development of the “Coral Tree,” a method similar to the one being implemented by the Coral Gardeners in Mo’orea. CRF is currently growing a huge quantity of genetically diverse corals (over 300 genotypes and over 42,000 corals at a time) in seven offshore nurseries for replanting in the surrounding reef. Corals are incredibly resilient, which is especially important during storms and hurricanes. According to CRF, the tips of branching corals will break off during high energy events and will lodge in crevices or cracks to grow into new colonies. When reefs are degraded and have lost their complex structure, coral fragments have no place in which to lodge, and so they roll around and die.
CRF’s gardens are helping to fill in these spawning gaps as the effects of climate change, namely warming oceans and increasing storms, affect the delicate ecosystem surrounding the coral, specifically algae overgrowths that prevent coral regeneration. This is compounded by a dwindling sea urchin population, which also eat algae and keep it in check. The coral reefs are a prime example of how the issues facing our oceans, our climate, our planet and our future are far from one-dimensional.
In a recent report, the Intergovernmental Panel on Climate Change (IPCC) highlights the dire effects of warming seas, such as acidification, sea level rise and coastal extreme events, which are all impacting oceanic ecosystems. Adapting to these changes can no longer be avoided. The work of Coral Gardeners and other reef restoration groups is an example of the community-led involvement at a higher level that is now necessary in the face of these rapidly deteriorating conditions.
This need for policy change and community involvement is highlighted stateside in Florida, where agricultural runoff and billions of gallons of raw human sewage are being dumped on the reefs. While solutions are being sought, including a complete stop on outflows in 2025, much of the damage is already done. The sewage spreads diseases directly from human guts to the reef and sea. Similarly, agricultural runoff from nearby pineapple plantations was a primary human-driven killer of the reefs in Mo’orea.
Back home in the alpine tundra of the San Juan Mountains and the desert tributaries of the Colorado River, I find myself not only more compelled to understand the direct effects of human impact and climate change on these areas, but also what actions I can take to make a measurable difference. The dying reefs are tragic, but their passionate defenders give me hope and inspiration. Spending that day on the water in Mo’orea pushed me to contribute public comments opposing proposed changes to the National Environmental Policy Act that would limit opportunities for public engagement and environmental review for development projects. I also joined conservation groups like Grand Staircase Escalante Partners to defend public lands from energy extraction projects that contribute to climate change. Whether our feet are on the ground or in the water, we can all be stewards for the wild places around us.
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Coral Restoration Foundation works to restore coral reefs, educates on the importance of our oceans, and uses science to further research and monitoring techniques.