A new technique can speed up coral growth by 25 times by breaking them into tiny little pieces. Discovered accidentally the process could now help replenish coral reefs and protect them from degradation. But how does it work? And why is it so important?
Dr David Vaughan was close to retirement several years ago before discovering a revolutionary new technique for speeding up the rate of growth in endangered corals. Now along with his team at the Mote Marine Laboratory in Florida he is on the front line of protecting coral reefs from the effects of climate change. Up to half of the coral on reefs in Florida and the Caribbean is believed to have been lost to bleaching and other diseases in the last few decades. Unfortunately corals are naturally very slow growing and are unable to recover faster than they are destroyed. But Dr Vaughan and his team are now turning this around by breaking corals into tiny little pieces. The technique known as ‘microfragmentation’ can help corals grow 25 times faster and the aim is to now use it to grow one million corals to replant back on Florida’s reefs.
One of the main things coral reefs are running out of, apart from an abundance of coral, is time. Rapid ecological change brought about by rising sea temperatures, ocean acidification and other human caused stressors is massively reducing coral coverage on reefs around the world. The problem is they are so slow growing they cannot recover faster than they are destroyed. In particular ‘massive’ species such as brain, star, boulder and mounding corals which can be centuries old. These types will only grow a couple of centimetres a year and a colony will take decades to form. This has earned them the nickname ‘living rocks’ and is the reason why they are most at risk from things like coral bleaching. Some faster growing branching species such staghorn can be regrown relatively quickly in nurseries and introduced back onto the reefs. But until recently this has not possible for the ‘massive’ corals because it takes too long to grow them.
A happy accident
Dr David Vaughan is a highly experienced coral reef scientist and leads the coral restoration programme at the Mote Marine Laboratory research station in Florida. He accidentally stumbled onto a new technique of rapidly growing massive corals whilst moving some in a tank. He was frustrated by the slow growth of some samples of Elkhorn coral and decided to move them to a different area of the tank. As he picked it up and moved the sample some of the polyps (individual units of coral) broke off and fell to the bottom of the tank. He deemed them to be as good as dead and left them there claiming they would ‘be toast’. But when he returned a couple of weeks later what he discovered shocked and inspired him. The polyps had multiplied and grown to the size of the original sample which had previously taken over two years to grow. Dr Vaughan was close to retirement at the time of his discovery but claims “once we saw there was this technology for restoration, I had to stay”.
So why is it that breaking apart corals helps them grow faster? It is because when the corals are broken up it stimulates rapid healing and growth to replace the polyps it has lost. This growth rate is at least 25 times faster than the growth rate from larvae and means corals can be grown in weeks and months rather than years. So instead of collecting coral larvae and waiting for them to settle and grow the researches take a living coral and break it into tiny pieces which will all grow back into equally sized pieces in a fraction of the time. After a couple of months the coral cultures are developed enough to be planted on existing reefs in Florida to replace those that have been lost due to bleaching and disease. What’s more because the new corals are all genetically identical to each other they fuse together easily and form large colonies that would have taken decades to develop naturally. In essence what microfragmentation does is give nature a helping hand to regenerate reef ecosystems.
Preparing for the future
Microfragmentation not only increases the growth rates of corals but exponentially increases the numbers that can be produced. One coral can be turned into hundreds, which can be turned into thousands, which can be turned into tens of thousands and so on. The aim of the team at Mote is to eventually introduce one million corals to the Florida Reef Tract, the third largest coral reef system in the world. Not only are they planning on replacing the corals there they are also trying to identify which species will be best suited for future conditions. Climate change is only going to increase the temperature and acidity of seawater over the next century. The researchers are now creating specialized tanks to mimic these conditions and see how it effects growth rates of different species. Hopefully this will help prepare for the problems that will arise before they happen rather than reacting to them which is what has been happening in the last few decades in coral science.
Why is it so important?
Speaking about microfragmentation in a video for the Atlantic Dr Vaughan describes growing a century old coral back to life as “like science fiction”. But what is it that makes it so important to coral reefs and their chances of survival? Coral reefs only cover 1% of the seafloor but are home to over 25% of marine life. This not only makes them very important ecologically but also economically for places like Florida. Dr Vaughan compares corals in reefs to trees in jungles explaining “If we lose the jungle, we lose all the organisms in it”. Globally we have already seen serious deterioration of the health of coral reefs and as a result knock on effects to those ecosystems. But Dr Vaughan goes on to say “there is no reason that worldwide we can’t replace corals and get them (coral reefs) back to where they used to be”. This technique will not magically make the problems facing coral reefs disappear but it will give them a much better chance of survival and recovery in the future.
Watch Dr Vaughan talk about his work in this video by Mote Marine Laboratory.