Coral reefs offer marine protection for communities, fish sanctuary and millions of dollars in conservation and tourism, among other benefits. Yet corals are also seriously endangered by increasingly deteriorating environmental conditions. Learn how Coral IVF is aiming to preserve these ecologically important ecosystems.

Why Do We Need Coral Reef Restoration?

Coral reefs today are under threat worldwide (ICRI, NOAA, Reefbase). It’s nothing new, but the degree to which corals are dying across the globe is disturbing. The effect of current climate change, directly impacting coral reefs by the already observable increase in seawater temperature, was evidenced by the third global bleaching incident in 2015/16. The incident triggered a mass die-off of corals.

The regeneration of degraded coral reefs may be assisted by a well-designed recovery plan. However, it can only be effective if local causes of coral loss are tackled. More significantly, we need to reduce our carbon dioxide emissions to reduce ocean warming (ISRS consensus statement: Climate Change Threatens the Survival of Coral Reefs).

Coral IVF

For the first time in the world, researchers have successfully invented small-scale reef regeneration using a method called Coral IVF. Coral will only spawn once a year in a natural occurrence that has been described as an underwater snowstorm of millions of tiny little dots released into the ocean.

During the activity, the researchers collect coral eggs and sperm from healthy reefs to rear millions of baby corals in specially built reef enclosures and in tanks before transporting them to small areas of degraded reefs to rebuild and repopulate them. The baby corals land on these reefs, and in years to come they will grow to the size of the plate, and beyond this point they will sexually reproduce and have their own coral baby, thereby restoring the breeding population of the damaged reef.

The success of this world-leading study relates not only to the Great Barrier Reef, but to all coral reefs around the world. We may continue to rebuild and fix endangered reef communities where the natural supply of coral larvae has been compromised.

The research team led by Professor Peter Harrison of Southern Cross University pioneered this groundbreaking strategy for the first time on Heron Island in 2016, returning the following year to assess results and produce more coral babies. Professor Harrison, a real innovator in his profession, co-discovered the concept of mass coral spawning more than 35 years ago. The team extended its study to the northern areas of the Reef in 2018 and 2019, creating new baby corals at Moore Reef near Cairns.

Early Signs Of Success

Despite the most extensive bleaching event ever recorded, more than 60 coral colonies born during the first Great Barrier Reef Coral IVF reef trial in 2016 have been found to survive and are likely to spawn next year.

This is a great achievement and an exciting start to this pioneering project. The Great Barrier Reef Foundation has managed to raise coral babies from microscopic larvae to the size of dinner plates, having not only survived a bleaching case, but now it appears like these corals are on track to start reproducing themselves, which would further help to regenerate the damaged reef.

Researchers are proud to report some promising findings after returning from a research trip to Heron Island to review the progress of 2016 coral babies and to run more Coral IVF trials. They find vigorous branching Acropora colonies that are on track to start reproducing themselves at the reef larval regeneration sites that settled larvae that were investigated four years ago during the first small-scale pilot study.

The Great Barrier Reef is the world’s largest living thing on Earth, with rich corals covering an area visible from space. Although the world is trying to mitigate greenhouse gas emissions, there is also an immediate need to investigate and improve techniques and solutions now to preserve the Reef for future generations, minimize more losses, help the devastated reefs regenerate and restore vibrant marine habitats.

Unfortunately, however, researchers have confirmed that the coral populations at the control sites, where they did not add any larvae and left them to see what had occurred, remained the same and practically no natural recruiting of new corals had taken place at those sites. But after seeing the promise of this game-changing strategy, the Great Barrier Reef Foundation is collaborating with experts, developers and innovators around the world to test new interventions and embark on the world’s largest reef regeneration and adaptation program.

Coral IVF is the first initiative of its kind to restore coral from destroyed reefs by harvesting millions of coral eggs and sperm during the spawning season, converting them into baby corals and returning them to depleted parts of the Reef. Today, as part of the world’s largest coral reef initiative, the Reef Regeneration and Adaptation Program, this strategy is being scaled up with the goal of achieving kilometer-long restoration around the Great Barrier Reef in cooperation with Southern Cross University, CSIRO and QUT, and with the help of the Australian Institute of Marine Science.

Future Implications

Experts agree: there is no way to repair coral reefs around the world with a single ‘silver bullet.’ What is required is a variety of strategies that work together. Techniques that can not only benefit the world’s largest reef, but also improve the protection of coral reefs across the globe and the populations that rely on them.

We should bear in mind that the reefs that we will be able to rehabilitate may not become the reefs that they used to be. Coral conservation activities may seek to rebuild the ecological functionality of coral reefs, such as the habitat of diverse animals and plants, the preservation of biochemical cycles and the maintenance of economic services such as coastal protection, fisheries and tourism. Endangered core species, such as elkhorn coral, which have trouble reproducing and coping with an evolving climate, can even be rehabilitated.

We are hopeful that well-designed restoration strategies, integrating the main restoration measures themselves with research, outreach and conservation and the active participation of partners in on-site initiatives, would give coral reefs a good chance for the future.