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The Coral Gardeners hang small corals on lines off Moorea until they are big enough to be settled in the reef
Photo:
Ryan Borne / Coral Gardeners
Taiano Teiho visits the nursery every day and examines his protégés. His workplace is not visible at first glance - because it is under water. The 23-year-old looks after small fragments of coral that hang on metal structures similar to clothes racks. Several pieces are attached to each leash, some the size of a fingertip, others the size of a hand. You are part of a project to preserve one of the largest ecosystems on earth: tropical coral reefs.
Coral reefs are the habitat for a quarter of all marine species. According to estimates by the Global Coral Reef Monitoring Network, around 500 million people worldwide are dependent on the reefs. So also the residents of Teiho's place of residence, the South Sea island of Moorea in French Polynesia. The French overseas territory consists of 118 islands and is located in the middle of the Pacific - about five hours by plane from New Zealand and eight from Los Angeles. Teiho's coral fragments lie in the lagoon around Moorea, the island is also known as Tahiti's little sister.
Climate change threatens the corals on Moorea - and those around the world.
The Intergovernmental Panel on Climate Change (IPCC) assumes that 70 to 90 percent of the reefs will disappear if the temperature increases by 1.5 degrees Celsius.
In addition to the pollution of the oceans, marine heat waves are the enemy of the corals.
They can't stand rising temperatures well.
If the water becomes too warm, they will bleach.
"Some coral stocks in the reef only grow an inch a year," says Teiho.
"If you find her dead in the water, that will do something to you."
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Taiano Teiho
Photo: Ryan Borne / Coral Gardeners
Teiho works for the Coral Gardeners - an organization that takes care of growing corals.
The small fragments are supposed to complete the reef of the island.
To do this, Teiho and his team remove around ten percent of a healthy coral.
Each fragment is supposed to become its own coral stock, on average it takes twelve to 18 months to settle.
Depending on the season, the water temperature off Moorea is 27 to 29 degrees Celsius.
Equipped with a diving mask and weight belt, Teiho goes to a depth of around two meters and cleans the metal construction.
He frees them from deposits that take away the light from the fragments.
Teiho dances back and forth on the metal rods weightlessly, lashing the lines tight when they have loosened due to the increasing weight of the coral fragments.
Witness one of the heaviest coral bleaching
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Titouan Bernicot
Photo: Ryan Borne / Coral Gardeners
The realization that the reef of his island in the South Pacific was changing came unexpectedly: five years ago, the then 18-year-old wanted to go surfing with his friend Titouan Bernicot.
They both grew up on Moorea.
That day, "we saw large Pocillopora verrucosa under our feet, but they were white," says Bernicot.
Where doctor fish, parrot fish and triggerfish previously lived, they now only found a collection of calcareous skeletons.
Teiho and Bernicot witnessed one of the heaviest coral bleaching seen to date.
It also happened elsewhere on earth, such as the Great Barrier Reef in Australia, where more than 90 percent of the corals were affected.
Corals are neither stones nor plants.
They consist of colonies of polyps, i.e. small cnidarians that enter into a symbiosis with so-called zooxanthellae.
These are algae that settle in the outer wall of the coral and carry out photosynthesis.
They pass nutrients on to the polyps.
If the water temperature is too high, the photosynthesis of the algae is inhibited.
Instead, the alga then produces toxins.
The coral then tries to get rid of it, repels it and loses its color.
But without the community of convenience with the algae, the polyps cannot survive permanently: If the water does not cool down again within a short period of time, the coral dies.
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Coral species Pocillopora verrucosa
Photo:
Ryan Borne / Coral Gardeners
Teiho and Bernicot know: It is normal for parts of a reef to be destroyed at regular intervals.
Like after a forest fire, space is created for new life.
However, due to the climate crisis, extreme marine heat waves occur at ever shorter intervals.
The reef therefore has no time to regenerate.
More than 15,000 super corals planted so far
For Bernicot, after their discovery, it is clear: he and Teiho have to do something.
Bernicot started a small coral farm.
But the project has grown over the years, and the organization now has more than 20 employees.
The Coral Gardeners have so far planted more than 15,000 corals in the Moorea lagoon.
They do this by selecting fragments of corals in large resilient colonies.
Because individual species are more resilient to various stress factors.
These so-called super corals should be able to withstand future temperature fluctuations and other harmful influences.
"To save the reef, we must all rethink the way we live"
Titouan Bernicot, Coral Gardeners
However, the fact that not all coral species can be considered as super corals will affect diversity in the future.
The Coral Gardeners plant 30 different species - but there are more than 800 species in total.
The work of the Coral Gardeners is financed through donations and a coral adoption program.
The team is part of a larger movement: There are similar reef restoration projects around the world - for example Corals for Conservation (C4C) in the Fiji Islands and Plant a Million Corals in the US state of Florida.
The team is in contact with them and many others.
They benefit from each other, exchange ideas and share knowledge about their work.
Another goal of the Coral Gardeners is to raise awareness of the threats to the reefs. After all, not only the reef of the small South Sea island of Moorea should be saved, but also the coral colonies in other parts of the world. By 2025, the Coral Gardeners want to plant a million corals with the help of future branches. They also want to use social media to reach people who do not live directly on a reef - because their behavior also affects their condition. Bernicot says, "To save the reef, we must all rethink the way we live."