Thanks to climate change, the ocean is no longer a friend of Seychelles. But can its reefs offer this embattled nation a lifeline?

The meteorological event, a combination of ocean heat redistribution and wind reversal in the Pacific, occurs approximately every two to seven years and has far-reaching consequences. The last El Nino in 2016 was similarly dreadful, reducing coral coverage on Seychelles' reefs from 50% to 5%, say local researchers.

El Nino is a phenomenon: a devastating, uncontrollable exception to the norm. With carefully managed conservation, Seychelles can survive its wild fluctuations. But not if global warming continues. As baseline temperatures creep up, the ecosystem loses its ability to recover. Eventually El Nino could prove terminal.

"People that don't believe in climate change, maybe they need to come to the Seychelles," says Lisa Laporte Booyse, who runs a guesthouse on the southeast tip of Mahe, the largest island in the chain.

"We can show them photos of things that were very different before ... coastal erosion. We can see flooding that we never experienced, the higher temperatures that we've never experienced before. The season(al) changes that have had an effect."

"Before, we literally could tell you the day that our rainy season would start. Now, we have droughts that we never experienced before."

Bleached coral close to the coast. Coral coverage dropped from 50% to 5% on reefs in 2016.

So much of the affairs on land are dictated by the health of the biosphere in the water.

When it comes to coastal erosion, reefs are key, acting as a wave breaker protecting the shoreline, explains Savi Leblond, project leader at the Cerf Island Conservation Program, 2.5 miles off the coast of Mahe. Without strong reefs, the land is at the mercy of the ocean. At present, they are delicately poised.

"Our reefs here have been under several threats -- natural and anthropogenic," Leblond says.

Sea surface temperature rises cause "stress" to corals, which release an algae zooxanthellae, which makes up "90% of its food source, as well as its color." The result is bleaching and depleted nourishment. Bleaching is reversible, but if waters remain too warm for too long, coral starves and dies.

A turtle swims among bleached coral in Seychelles.

Either of these eventualities would be a catastrophe for Seychelles' biosphere -- above and below water.

"When corals die off, unfortunately we die off," surmises Leblond. "Everything relies on coral reefs."

"It was the fishermen who said it's not like it was before," recalls Booyse.

Seychellois look to the sea for sustenance; they're custodians of over 500,000 square miles of ocean, and 15% of the population are engaged in fishing and fishing-related activities. But it's already proving harder for fisherman like Augustin Desaubin and others to eek out a living.

As a boy Desaubin remembers "the corals were beautiful; plenty of coral inside the reef, plenty of fish," he adds. "Now we can see only seaweed."

"When I was young, octopus was abundant. I (would) dive for about one hour, you'd have five or six octopus and go home." Now approaching 50, Desaubin says there are days when he returns empty-handed.

"Corals cover less than 0.1% of the world's surface area but they house over 25% of the world's biodiversity," Leblond explains.

"We, the People of Seychelles, grateful to Almighty God that we inhabit one of the most beautiful countries in the world; ever mindful of the uniqueness and fragility of Seychelles... declar(e) our unswaying commitment... (to) help preserve a safe, healthy and functioning environment for ourselves and for posterity."

Alongside government initiatives, citizens are taking action.

"We grow corals in a nursery and use these nursery-grown corals to rehabilitate the reef," explains marine scientist Jude Bijoux. Due to climate change, only corals most resilient to warm temperatures are selected, he adds.

The time-consuming process involves transferring coral fragments from one of five artificial reefs to rope lines, then to substrate or natural rock on the sea floor. It's a six to 12-month effort requiring epoxy resin and regular rope cleaning with a toothbrush.

"It's a bit weird," says Leblond, but their methods give coral "the best chance they have."

Rope-grown corals are tended to as part of reef rehabilitation.

Inspired by initiatives on Cerf, Booyse started the Anse Forbans Community Conservation Program, a group of neighbors setting up a coral nursery of their own.

"(It) won't be an immediate fix," Booyse says. "We're looking at a five-year lifespan to get the corals healthy, growing again and plant them back."

Even among one of the greenest societies in the world, ownership and responsibility lie at the heart of Booyse's motives. "My own generation, and generations before, have made a big impact on the environment," she says. "I have to try and lead and make a difference."

"When you're fighting the cause you've just got to go and keep going."

Seychellois know that in the fight against climate change, no half-measures will do. Their livelihoods and homes depend on it.

More:

'When corals die off, we die off' - CNN