Is Restoring Reefs a Waste of Effort?

It's not a message any diver will want to hear, but independent research into coral restoration projects worldwide has led scientists from Flinders University, the University of Western Australia, and the University of Helsinki to a tough conclusion.

When corals die or become damaged, many people try to restore them. But the enormity of the task is growing as the climate keeps warming.

In this new research, the scientists examined the full extent of coral restoration projects worldwide, what drives their success or failure, and how much it would cost to restore what's already been lost. Restoring the world's reefs that have already been lost could cost up to $17 trillion.

Over the past 40 years, the extent of coral reefs has halved. As climate change continues, bleaching events and coral deaths become more common. More than 90 percent of coral reefs are at risk of long-term degradation by the end of the century.

When it comes to coral gardening, the problem is one of scale. Coral restoration can be done successfully only at a limited scale. Most projects operate only over several hundred or a few thousand square yards. Compare that with nearly 4,650 square miles of loss and degradation between 2009 and 2018. Restoration projects cannot meet the scale needed to offset losses from climate change and other threats.

Coral restoration is expensive, ranging from around $10,000 to $226 million per hectare. The wide range of costs reflects the variable costs of different techniques used, ease of access, and cost of labor.

Their conclusion: it's financially impossible to tackle the ongoing loss of coral reefs with restoration; however, some local projects may still offer some benefits in preserving fish population and attracting divers.

What do we learn from this? There's no substitute for climate action now.