The effects of global warming are far and wide. Nothing on planet earth is immune and it is delicate ecosystems that suffer the most. Some of these ecosystems which are extremely threatened by global warming are coral reefs. Coral reefs are full of diverse marine life, with amazing animals and beautiful corals. 

However, because of the warming oceans, these corals are bleaching and dying. The Climate Council of Australia reported that surveys of the Great Barrier Reef show that 93% of individual reefs have been affected by bleaching. Bleaching does not necessarily mean the corals will die, but it is very likely as the zooxanthellae that live in the coral’s tissue and provide it with essential nutrients are dispelled. This leaves the corals very vulnerable.

If humanity does not change soon and help, the coral reefs will die and the ocean will suffer. Because of the huge amount of marine life that depend on coral reefs, life on earth will change drastically and we all will be affected. Everything in nature is linked, and this includes us. 

Because of the crisis that we are facing, scientists are working hard to understand coral bleaching and figure out ways that we could help. In understanding the connection and interaction between bleaching and coral genes, perhaps there are ways in which we can help coral reefs around the world. 

In November 2020 a team lead by Phillip Cleves discovered that the CRISPR genome editing system provided insights into coral bleaching. But what is does it mean to edit genomes, and what does it mean for the future of coral reefs? Does it open doors for coral conversation? 


Firstly, it is helpful to understand what CRISPR is. This is a fairly new tool and allows for the editing and replacing of genes. According to the New Scientist, CRISPR finds a specific bit of DNA in a cell and edits it. This way of editing genes is quick and pretty cheap compared to previous technologies. It is also really precise, cutting DNA like scissors. This means that scientists can target specific genes, editing them, or replacing them. 

This technology will most likely bring about a great deal of positive change in the world. In 2018, scientists implemented CRISPR to reduce genetic deafness in mice that were caused by genetic factors, and this is just the start of the amazing things that CRISPR can do, and hopefully will do. According to the New Scientist, CRISPR will be used to prevent and fight diseases in humans. Scientists are using CRISPR to find ways of treating rare liver conditions and diseases. In 2017 a group of scientists used CRISPR to treat muscular dystrophy in mice and did so successfully. This gives us hope that we can use this method to treat humans with this condition too. 

As we can see, CRISPR is an exciting and monumental scientific development that has so much potential. But what about corals?

How Has CRISPR Helped Scientists Understand Coral Bleaching?

Phillip Cleves of Carnegie Institution for Science lead a team of researchers that used CRISPR to find the gene in corals responsible for how the coral responds to heat stress. This has the end goal of fighting against the mass bleaching that is killing coral reefs around the world.  

According to an article published by the Carnegie Institution of Science, the team firstly identified a protein in sea anemones that activate genes that are associated with heat stress. This protein is called Heat Shock Factor 1 (HSF1). Because anemones are closely related to corals, this study gave hope that there will be similar findings with corals. 

The next study that the team conducted involved corals. They used the stony coral Acropora millepora. As Acropora corals make up a huge amount of the coral reefs around the world, learning about the genes of these will be incredibly helpful in regards to reef conservations. 

In this study, the team created mutations in the gene that encodes the protein HSF1, which was the protein studied in anemones. They found that if the coral did not have a functioning HSF1 protein the coral did not survive when the water they were in got warmer. The study found that the corals that were not edited with a faulty HSF1 protein survived at the same temperature in which the edited corals died. 

This suggests that there is a link between this certain protein, the genes that are activated by this protein, and the coral surviving or not surviving heat stress. 

What Does This Mean For Reef Conservation?

Identifying the genes that are involved in the bleaching process and heat stress has great implications for reef conservation and gives us a glimmer of hope!

Because we are learning more about the genetic codes we are learning about how the coral reefs react to global warming. The studies conducted by Phillip Cleves have shed light on the fundamental biological makeup of corals. Specifically, we now have a deeper understanding of the genes associated with heat stress. 

When it comes to protecting and maintaining the coral reefs around the world, the next step is looking at how we can implement these discoveries.

According to Dr. Line Bay, who is an AIMS Principal Research Scientist and the head of the Reef Recovery, Restoration and Adaptation Team, now is the time to look at how we can manage coral reefs with these findings. Dr. Bay suggests that ‘novel management tools such as selective breeding and movement of corals amongst reefs’ can now be looked at, with the benefits and risks being balanced. 

There is still a long way to go in order when it comes to reef conservation, with so much work needed to be done to even begin to reverse the damage that humans have caused. However, there are scientists that are dedicated to saving the wonderful reefs that exist in the oceans of the world. 

We are here to spread the word about the wonderful work these scientists are doing, and how we need to come together to save the reefs!