I had been home for six months when the email arrived: “With the help of photosynthetic algae and guard crabs, enough sunlight and the right temperature, Betsy Andrews has managed to grow exceptionally well . Almost all of your corals have doubled in size.

No, it wasn’t some kind of Little Mermaid cosplay. It was an update on the coral colony I had planted – and labeled with my own name – in the Indian Ocean, just off the beach of Velaa Private Island. My facility is one of many aimed at helping to reverse a mortality that is occurring not only in the Maldivesbut across the world.

The Velaa Coral Keepers Program is one of several urgent reef restoration projects underway at resorts across this country of 1,192 small islands. In the Maldives, coral is everything. It supports the fish that people eat. It protects beaches from erosion. It is the very foundation of the economy. “People from all over the world come to these beautiful reefs to dive and snorkel,” says Velaa marine biologist Agnė Griciūtė. “And unfortunately the reef is in trouble.”

I had a closer look at the situation during my visit to Velaa, when I went on a series of scuba dives with the resort’s dive master, Marta Pasztorova. We saw massive walls and pinnacles of coral shaped like rocks, fans and wood. Schools of blue triggerfish and five-banded bass flowed down their sides. Moray eels and groupers were emerging from their crevices. Sharks and rays passed by. Napoleons would stop at grooming stations to have their anvil-shaped heads nibbled on by tiny gobies. And millions of other colorful and bizarre fish went about their business on the reef.

But all this was happening at a depth of 60 feet. Closer to shore, the picture was not as rosy. “Do you know what bleaching is? » » asked Griciūtė. “Coral is an animal, like humans. When it’s too hot, it dehydrates. And it’s just as problematic for corals as it is for humans. When overheated, coral expels the colorful single-celled organisms that live there. These zooxanthellae, as they are called, convert the sun’s energy into nutrients for the coral; without them, the coral turns white and begins to starve. Bleaching can be periodic, following events such as El Niño, which can create particularly hot and dry weather.

“However, if conditions improve – if temperature and ultraviolet light decrease – zooxanthellae return, bringing back color, and some corals survive,” Griciūtė explained.

The restoration aims to multiply these survivors, because, according to the theory, they must have adapted to the new, warmer conditions.

Griciūtė led me to a table in the sand, where an intern, Henry Garber, had set up tethers, a bucket of seawater filled with coral fragments, and a frame of rebar in the shape of an eagle ray. We attached 15 fragments to the frame. Then we hopped in a boat and headed to a nursery in 30 feet of water, well away from the larger reef – and any coral-munching parrotfish or cushion stars. Garber donned a tank and lowered the frame to the seabed while Griciūtė and I watched from the surface with snorkel gear.

The current El Niño, which began in early 2023, has affected 70% of the planet’s coral reefs, in 67 countries. This is the second such event in a decade; the previous one, from 2014 to 2017, prompted Velaa and other Maldives properties to take action.

“Resorts have a responsibility to protect their home reef,” said Arnfinn Oines of the Soneva Foundation, which supports coral restoration in Soneva Fushi. Guests can tour a laboratory run by the nonprofit Coralive, where coral reproduces and grows under controlled conditions before being mature enough to be placed in the sea. Offshore is one of the largest nurseries underwater world that uses mineral accretion technology, or MAT, a weak electrical current that causes limescale to build up on the frames, which encourages corals to grow up to three times faster.

At Four Seasons Resort Maldives in Landaa Giraavaru, the nonprofit Reefscapers has planted more than half a million new corals. Guests can also get involved in projects at resorts such as Sheraton Maldives Full Moon Resort & Spa, Siyam World Maldives, Baros Maldives, and the St. Regis Maldives Vommuli, where Reefscapers has just launched a new nursery.

Although participating during the holidays may seem like a drop in the bucket, scientists and advocates I spoke with said every effort counts. “The goal is not only to create more coral cover, but also to create adaptive opportunities for corals,” says Ahmad “Aki” Allahgoli, founder of Coralive. “We need to plant as many corals as possible – and we can’t do it ourselves.”

Paddling around Velaa Lagoon, our masks in the water, Griciūtė and I looked at other methods his team is trying: stainless steel ropes suspended from growing corals; MAT wired frames; PVC trays for feeding soft corals. Then she pointed to metal adoption tags nestled among coral mounds teeming with fish. These sturdy strips of reef came from fragments like the ones I had planted.

Back home, looking through photos of my own colony, I noticed that it was on its way to reaching a similar maturity, while the reef around Velaa was being cared for.

A version of this story first appeared in the November 2024 issue of Travel + Leisure under the title “Under the sea”.