If the world wants coral reefs and soft sand beaches in the future, it will have to grow them itself.

That was the intriguing message from Tom Goreau, president of the Global Coral Reef Alliance, on a recent visit to Cayman.

Goreau argues that the impacts of climate change, particularly ocean warming, are irreversible and that the loss of reefs will only continue.

His solution sounds like something out of science fiction – using electric current to supercharge the regrowth of coral reefs destroyed by climate change. 

But the concept has worked successfully in the Maldives and Indonesia, and on a limited basis in parts of the Caribbean.

And the marine biologist believes it could be a solution not just to help revive Cayman’s beleaguered reefs, but also to protect its beaches from further erosion.

Goreau was in Cayman last month where he gave two talks – one in support of the CPR campaign against cruise berthing and another detailing his concern for the future of coral reefs.

He told the Compass that reefs across the world have been reduced to rubble, and bleaching caused by rising ocean temperatures is accelerating the decline.

Without human intervention, he believes they won’t survive and warned that everyone will pay the price.

What’s the big idea?

Put simply, the idea is to build new coral reefs.

Scientists Goreau and Wolf Hilbertz, also with Global Coral Reef Alliance, have developed a method of using electric current to ‘grow’ limestone around metal structures on the sea floor.

Some corals – like the staghorn and elkhorn corals that have been decimated in the Caribbean over the fast 50 years – can be fragmented and will grow quickly on those new limestone crusts.

It is basically a supercharged version of the types of coral-growing projects already seen in parts of Cayman – which use metal frames as scaffolding for fragmented corals in shallow-water nurseries.

The aim is to give nature a helping hand amidst the dual impacts of warming and pollution on the health of oceans.

The electrification grows the limestone and speeds the growth of coral, attracting sea life to the new reefs.

Does it work?

The technology is actually fairly simple and pretty well established.

Goreau cites projects around the world where new ‘electric reefs’ have grown and attracted marine life. 

The best examples are in the Indian Ocean, particularly Indonesia and the Maldives.

Coral reefs have essentially been grown from scratch.

The BBC highlighted the success of the methodology in the Gilly Islands of Indonesia, off Lombok.

Goreau’s foundation has more than 150 ‘electrified reefs’ off Indonesia, where corals have come back at surprising speeds.

There are smaller-scale examples in the Caribbean including in Turks and Caicos.

What has happened to Cayman’s reefs?

Bleaching caused by warming oceans, pollution and dredging for ports have seen coral coverage impacted across the Caribbean.

Cayman has been hit less hard than its neighbours – its clear, clean water and relative lack of pollution providing an environment where survival chances are higher for corals.

However, the effects over the past 50 years have still been catastrophic.

Coral cover on Cayman’s reefs reduced from 80% in the 1970s to around 10% by the early 2000s.

And the climate impacts are worsening. 

The last two years were the hottest on record and mass coral bleaching across the Caribbean, including in Cayman, has taken its toll.

Why is this a problem?

Aside from the purely selfless concern for the degradation of a natural environment, there are certain ‘economic services’ provided by coral reefs.

Globally, coral reefs support more than 4,000 species – so fewer corals mean fewer fish mean less food. The reefs also support the dive industry and the wider tourism industry, and provide critical coastal protection.

That layer of protection has atrophied over the past several decades, leaving Cayman more exposed to storm threats than in previous generations.

The loss of huge fields of shallow-water branching corals like elkhorn and staghorn, which used to be abundant in Cayman and now exist only in isolated pockets, is something anyone who has dived in the islands’ waters can attest to. Those are the corals that provide critical shoreline protection – breaking up waves as they sweep towards shore.

A lesser-discussed element of the ‘service’ provided by coral reefs is that they are producers of sand.

How do reefs create sand?

Fundamental questions – what is sand and where does it come from?

There’s a number of different location-specific answers to that question, but the fine-grain building blocks of Cayman’s beaches are produced by coral reefs.

“We call it coral sand, but it isn’t really coral,” says Goreau.

“Almost all sand here comes from red and green algae that grows on top of coral.”

One of the ways in which beaches are created is when reef fish – particularly parrot fish – graze on that algae and excrete it as sand.

So a well-functioning reef system would produce new sand, as well as reduce wave energy, says Goreau.

He cites examples in Indonesia and the Maldives where, over the course of little over a decade, eroded beaches have been restored or new ones created on coastlines where electric reefs have been established.

Could it help with Seven Mile Beach erosion?

The erosion problem of Seven Mile Beach has been well documented and is likely too far advanced to reverse swiftly.

There are a number of reasons for that – from seawalls and coastal development to the pattern of storms over several decades – which have led to an overall loss of sand from the system.

At this point, there is broad recognition that some form of replenishment may be required – likely on an ongoing basis.

One key challenge for any replenishment project is retaining the sand within that system.

Goreau points to examples in Galveston and Cancun where annual sand top-ups are required.

He believes new reefs in strategic locations on Cayman’s coastline would both protect its beaches and serve as a bulwark against the wave activity that is sweeping sand out of the beach system.

Will the idea catch on?

Around the world, funding for this type of work presents an ongoing challenge. 

Goreau’s projects have attracted support from resort owners and impacted businesses, from environmental foundations and non-profits.

But he believes – whether it is through his foundation or elsewhere – policymakers are going to have to get used to the fact that they must pay to rebuild ecosystems or suffer the cost of their loss.

“Everyone has regarded the sea as a free good. You take and you take and you don’t do anything to restore that ecosystem. We’re now paying the price for it,” he said.

Organisations like the Global Coral Reef Alliance struggle to attract government funding, he says, because they involve investment that has no direct financial return.

“What they’re going to get is environmental services, like ecotourism attractions, beaches, biodiversity and fisheries habitat. But it is not clear if anyone’s going to make money directly off that, so people are reluctant,” he said.

All the research and data, he says, points to climate change – in particular, warming oceans which cause bleaching and death in corals – as the key culprit. And that is not something that is going to change.

Lost reefs are not coming back and will continue to deteriorate, he warns.