epoxy resins
Climate change and the uneasy future of Seychelles.
Thanks to climate change, the ocean is no longer a friend of Seychelles. But can its reefs offer this embattled nation a lifeline?
'When corals die off, we die off'
By Olivia Yasukawa and Thomas Page, CNN
Updated 1:30 AM ET, Mon July 10, 2017
Thanks to climate change, the ocean is no longer a friend of Seychelles. But can its reefs offer this embattled nation a lifeline?
(CNN)In 1998, the cruel heat of El Nino hit Seychelles hard. Sea surface temperatures rose around the Indian Ocean, bleaching 90% of coral reefs in the archipelago. Widespread flooding caused significant economic losses -- fishing and agriculture accounting for more than half of the total figure according to the International Monetary Fund (IMF).
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.
Climate change has become the day-to-day struggle for this tiny nation -- an island nation that faces erasure should the problem remain uncurbed.
So what can a country with one of the smallest GDPs in the world do to prevent the global catastrophe lapping at its shores?
A survey of the threats
Headlines refer to the "slow creep" of climate change. In pockets of the world not yet on its frontlines, there is still doubt or ambivalence -- even from the highest offices in the land. Seychellois, however, can measure the effects with a yardstick along their coastline.
"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.
The IMF cites 2010 as Seychelles' "worst drought in decades," also noting that in January 2013 intense rain caused landslides in Pointe Au Sel, and in May 2007 extreme high tides spread 164 feet inland, striking roads and infrastructure. Locals are being forced to create ad hoc barriers from rocks to prevent beaches from being washed away.
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.
Seychelles: 115 islands vs climate change
Seychelles: 115 islands vs climate change 07:52
Another factor is ocean acidification, caused by bodies of water absorbing C02 -- 560 billion tons in the past 250 years, per one US national climate assessment. This has increased ocean surface acidity by 30%, preventing calcifying life forms, including coral, from absorbing the nutrients necessary for them to maintain their structure.
Then there is sedimentation, which starves coral of oxygen. The Max Planck Institute describes this, paired with acidification, as a recipe for a "deadly chain reaction" on reefs. Sedimentation can occur due to extreme weather events -- the 2004 Boxing Day tsunami covered some reefs in Seychelles -- but sediment can also travel via rain runoff and flood waters, caused by storm surges and rising sea levels.
A turtle swims among bleached coral in Seychelles.
Seychelles is particularly susceptible to rising seas. Many islands in the 115-strong archipelago are low-lying elevated reefs. Of the archipelago's combined land area, roughly two and a half times the size of Washington DC, 16.4% is less than 16 feet above sea level.
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According to Seychelles' ambassador for climate change Ronald Jumeau, 80% of the population live and 80% of economic activity occurs in coastal regions.
By 2100, the United States' National Oceanic and Atmospheric Administration predicts average global sea levels could rise over eight feet.
Meanwhile, a paper dated March 2016 suggested ice melt in Antarctica alone could add 49 feet to sea levels by 2500.
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."
Custodians of the ocean
"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.
After the storm: How to rebuild a coral reef
After the storm: How to rebuild a coral reef 07:39
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.
If coral degradation continues, it's not just the tourist industry that will suffer. But while some nations haver in their commitment to fighting climate change, Seychelles is ramping up its efforts.
Rebuilding the ocean from the floor up
Four years before the Kyoto Protocol (a precursor to the Paris Climate Accord) was signed, Seychelles placed the environment front and center of policy. Its constitution, penned 1993, begins as follows:
"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."
By January 2017 the IMF declared that "Seychelles has put climate change at the center of its sustainable development strategy, more purposefully than most other small states."
The Seychelles is making a difference
The Seychelles is making a difference 06:52
Alongside government initiatives, citizens are taking action.
Leblond and the Cerf Island Conservation Program, part of the Marine Conservation Society Seychelles, cleans coastlines with teams of volunteers. But rehabilitating reefs is a more intensive endeavor.
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"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."
The big move
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.
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Graphene sieve could make seawater drinkable.
Researchers in the United Kingdom have developed a graphene-based sieve that can filter salt out of seawater, a development that could provide drinking water to millions of people around the globe.
(CNN)Researchers in the United Kingdom have developed a graphene-based sieve that can filter salt out of seawater, a development that could provide drinking water to millions of people around the globe.
The applications could be a game-changer in countries where access to safe, clean, drinkable water is severely limited.
Graphene -- an ultra-thin sheet of carbon atoms organized in a hexagonal lattice -- was first identified at the University of Manchester in 2002 and has since been hailed as a "wonder material," with scientists racing to develop inexpensive graphene-based barriers for desalination on an industrial scale.
Now, the team at Manchester has used a compound of graphene, known as graphene oxide, to create a rigid sieve that could filter out salt using less energy.
Overcoming hurdles
In recent years, there had been some success in water filtration using graphene oxide to sift out other smaller nanoparticles and organic molecules.
But researchers had struggled to move forward after finding that the membrane's pores would swell up when immersed in water, allowing particles to continue to pass through.
Rahul Nair's team at Manchester now claims it has discovered how to control of the expansion and size of the pores.
Writing Monday in the Nature Nanotechnology journal, the team revealed it was able to restrict pore-swelling by coating the material with epoxy resin composite that prevented the sieve from expanding. This means common salt crystals could continue to be filtered out, while leaving behind uncontaminated, clean, drinking water.
The discovery is "a significant step forward and will open new possibilities for improving the efficiency of desalination technology," Nair said in a statement from the university.
"This is the first clear-cut experiment in this regime. We also demonstrate that there are realistic possibilities to scale up the described approach and mass produce graphene-based membranes with required sieve sizes," he added.
Global implications
Boosting global access to water is critical. By 2025, 14% of the global population will suffer from water scarcity, the United Nations predicts. In addition, climate change is expected to wreak havoc on urban water supplies, with decreased rainfall and rising temperatures expected to fuel demand.
Cities have been investing heavily in diversifying their water supplies, including developing new desalination technologies to make seawater potable. But existing, industrial-scale desalination plants can be costly and normally involve one of two methods: distillation through thermal energy, or filtration of salt from water using polymer-based membranes.
These techniques have drawn criticism from environmentalists, who argue they involve large amounts of energy, produce greenhouse gases and can be harm marine organisms.
What's next?
The graphene-oxide breakthrough has been welcomed by scientists in the field as a promising development, but some are cautious of the next steps.
"The selective separation of water molecules from ions by physical restriction of interlayer spacing opens the door to the synthesis of inexpensive membranes for desalination," wrote Ram Devanathan of the Pacific Northwest National Laboratory, in an accompanying news-and-views article in the journal.
More work still needs to be done to test the durability of the barriers and to confirm the membrane is resistant to "fouling by organics, salt and biological material," he said.
Water treatment with membranes that separate water molecules from ions, pathogens and pollutants has been proposed as an energy-efficient solution to the freshwater crisis, Devanathan added.
"The ultimate goal is to create a filtration device that will produce potable water from seawater or waste water with minimal energy input."
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