How One University is Hoping to Help Restore the Arabian Gulf’s Coral Reef

Sponsored by Zayed University

The climate crisis isn’t just having a dramatic effect on wildlife on land, but also on the wildlife in our oceans. The oceans’ coral reefs, usually teeming with sea life, are suffering and dying off through ‘bleaching’ as a result of increasingly hot summers.

But what can we do to help? We spoke with Dr Henrik Stahl, Associate Dean for the College of Natural and Health Sciences at Zayed University about his coral propagation research project to find out more. 

Why are coral reef ecosystems so important?

Coral reefs are an essential element of the ocean and are often referred to as “the rainforests of the sea,” said Dr Stahl.

They provide places to live as well as food for hundreds and thousands of marine organisms and fish, and so without an efficient coral reef ecosystem in our ocean it can have severe consequences for the wider marine ecosystem.

“They are incredibly important global habitats which need careful management and conservation if they are to survive.”

The Arabian Gulf has “the most extreme environment anywhere in the world where corals can survive,” according to Dr Stahl.

“But these ‘super-corals’ still have a limit, and over the past few decades, up to 70 percent of the coral reefs in the Gulf have been lost due to extreme temperature events causing coral bleaching, by pollution and urban development, such as land reclamation.

“So far, about 30 percent of global coral reefs have been destroyed over the past few decades and another 30 percent is threatened by 2050,” added Dr Stahl.

What is being done to help?

Over the last few years there has been a surge in the amount of studies and research projects which focus on the restoration and protection of coral reefs both regionally and globally by propagating coral.

Coral propagation helps the over-harvesting of coral from the oceans as well as the damage that pollution and climate change is doing to these fragile and valuable underwater ecosystems.

The externally funded research project conducted by Dr Stahl and his team at Zayed University is just one of them, and aims to develop new techniques to help restore degraded reefs in the Arabian Gulf by propagating delicate corals in order to place them back into their natural habitats.

The other problem also lies with the fact that other marine organisms and fish may feed on the eggs that are released by the coral. As a result, the natural success rate of fertilization is very low.

“The research essentially looks at ways to help corals to reproduce faster and more efficiently on the reefs,” explained Dr Stahl.

“We do this by collecting coral colonies from the wild, shortly before spawning, and bring them into our specially designed coral lab at Zayed University where we can isolate the corals during the few nights of spawning to collect all their gametes (the released eggs and sperm).

“After collection, we mix gametes from different parent colonies in a small volume of water and as a result significantly increase the success rate of fertilization of the coral eggs.

“Then we incubate the eggs until they metamorphose into their larval stage (by this stage we have thousands of coral larvae), which are now ready to settle on a hard substrate to form a new coral.

“After settling onto specially designed coral substrates, we nurture the coral juveniles in the lab for a few months, where we then redeploy them onto the natural reefs again where they can continue to grow into adult coral colonies.

“Up to now this has only been done on a small experimental scale, but the long-term aim is to be able to scale this up to a point where it can actually serve as a means for ‘seeding’ the natural reefs with new genetically diverse corals." 

So far, Dr Stahl and his team have had three successful spawning seasons where they’ve managed to redeploy hundreds of new baby corals on to the Arabian Gulf reef. However, there are still challenges when it comes to getting the settled corals to survive.

“We are now experimenting with different types of settling substrates and figuring out the optimum time to keep the coral juveniles in the laboratory before redeploying them into the wild,” explained Dr Stahl.

More still needs to be done

“Although active coral propagation is one way of helping coral reefs survive well into the future, this has to be done hand-in-hand with major efforts to mitigate climate change, pollution and other destructive practices and processes threatening the survival of the coral reefs. 

“As I see it, without these efforts, even active coral propagation won't help and is merely like doing CPR on a patient with heart failure,” said Dr Stahl.

Despite efforts in coral propagation proving valiant and positive, the world cannot rely on this as the only method of helping to ensure the active management and conservation of the Arabian Gulf’s coral reef ecosystem.

Dr Stahl’s research project team was made up of several research assistants – four of which were Zayed University graduates. A number of undergraduate students from the university were involved in the project as well – one of which was from a media and communication background and the others coming from environmental science backgrounds. A master’s student was also involved in the project as her thesis focused on coral propagation research.