Microfragmentation: a breakthough for coral reef restoration

Coral reefs are the most biodiverse ecosystems on the planet. They support about 25 per cent of marine life while covering less than 1 per cent of the seafloor.

The benefits coral reefs provide are endless. Not only are they the home of up to 9 million species but are a source of food, medicine, cosmetics and tourism, estimated to have an economic value of 5 billion dollars in the state of Florida alone. They are also essential for protecting our coasts; acting as a buffer against storms which reduces erosion. Being such an important and beautiful ecosystem, the loss of corals is devastating news.

Unfortunately, coral reefs around the world are declining at a rapid rate due to climate change, ocean acidification, disease, overfishing, pollution and other human-related factors. In some areas of Florida and the Caribbean, coral cover has declined by 50–80 per cent in just the last three decades.
Coral scientists are working hard to restore corals as fast as possible. At the Elizabeth Moore International Center for Coral Reef Research & Restoration they have managed to develop a micro-fragmentation and fusion method to speed the growth of brain-, boulder- and star-corals which are important reef-building species, known for their slow growth in the wild. They focus on optimising growth in the warmer more acidic conditions our oceans hold in the future.

The fragmentation technique consists of breaking the corals into smaller pieces of 1 to 5 polyps, using a specialised saw. This stimulates the coral tissue to grow, allowing them to grow into clones at 25 to 50 times the normal growth rate. The fragments are then places in their shallow water tanks at 22–26 degrees Celsius, algal growth and debris are removed regularly. Clone fragments recognise each other so instead of fighting each other for resources fuse together to form larger colonies. After 4- 12 months the fully grown corals are now ready to be planted back into the ocean or fragmented to restart the process.

Thanks to this technique, labs are able to fragment, grow and recombine corals in under 2 years to a size which would normally take 100 years, enabling much faster restoration of reefs. Furthermore, the recombined colonies become sexually mature, which would usually take up to 75 years. They have now successfully planted more than 20,000 corals onto depleted reefs in the Florida Keys.

Combined with selectively growing fragments of more tolerant corals which have survived of bleaching events, this technology has the potential to make a major contribution to coral restoration.

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