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Coral reef restoration: helping ocean ecosystems survive

Human intervention is now being encouraged to aid in the rehabilitation of coral populations after long being dismissed. Coral gardening efforts and the creation of underwater nurseries are yielding promising results.

Around the world, 362 reef restoration projects are working toward strengthening our ocean’s ecosystems – and exciting developments are underway.

In a small number of ocean regions, coral reefs are continuing to thrive despite the fact that around 50% of coral reefs have been irreversibly damaged by the effects of climate change.

Research has found that reefs situated in particular parts of the world have built up a tolerance to warmer, acidic waters. In the Gulf of Aqaba near Israel, coral species actually thrive in temperatures 6 degrees higher than expected, growing even faster in the region’s warmer months.

In the North Atlantic, the temperate climate near the island of Bermuda enables lush coral reefs to prosper year-round throughout both high and low temperatures. The island’s surrounding reefs can withstand temperature drops of up to 4 degrees below the norm.

Coral species from these areas are thought to be vital in fostering new reef populations that will be capable of withstanding the effects of a warming world.

Why are coral reefs so important?

Coral reefs cover about 2% of the earth’s ocean floor, but these living structures are responsible for sustaining a quarter of all marine life.

In a symbiotic relationship, reefs offer protective homes for smaller fish and an essential nesting ground for their eggs. Reef-dwelling fish return the favour for this safety, feeding on organisms that are harmful to living corals.

The strength of this 250 million year long relationship is under threat due to climate change. When oceans become too warm, stressed corals rapidly expel the colourful algae which lives in their tissues, causing the corals to become a bright white – this is known as coral bleaching.

A common misconception is that bleached coral is dead, but this is not always the case. Following a bleaching event, corals live an extremely vulnerable state without the algae providing its main food source. They are capable of recovering from an event like this, but as coral is slow growing, this process takes around 10 years.

As ocean temperatures continue to rise, this recovery period has been almost completely diminished. Despite this, there remains hope.

Coral gardening and underwater nurseries – a slow growing labour of love

Coral gardening is a key method by which volunteers are building new coral structures from already existing reefs. In a laborious and timely process, volunteers delicately snap off small pieces of living corals and transfer them onto underwater metal structures.

Unlike land plants corals lack roots, so divers are quite literally gluing or tying the pieces in place until they reattach themselves over an eight week period.  In Costa Rica, these foundations are being fashioned from the skeleton-like structure of previously living corals to “revive” old reefs.

Especially in areas where bleaching has destroyed natural ecosystems, the success seen from coral gardening is a triumph, as fish and other sea life have returned to make a home out of the newly grown reefs.

In further experiments, fragments of the most resilient coral are brought ashore and placed in underwater nurseries, otherwise known as coral sanctuaries. Here, they are exposed to different temperatures and water acidity levels to discover the parameters of their ability to blossom within extreme environments.

Species from underwater nurseries are later re-gardened and their growth is closely monitored. Scientists have already seen these corals successfully respawn, growing onto the reef naturally.

It remains a global effort to aid in the preservation of coral reef ecosystems. While it requires hard work and dedication, these fragile, yet resilient structures will become increasingly dependent on us in the warmer years to come.

Thanks to the efforts of hundreds of organisations across the world, hope for these vibrant, ocean ecosystems and the abundant marine life that relies on them is growing.


This article was originally written by Jessica Byrne. ‘I’m Jessica, a recent graduate from the University of the Arts London. I’m passionate about sustainable fashion and beauty, racial and gender equality and protecting our oceans. When I’m not curating Spotify playlists, you can find me watching every existing documentary on my latest subject of interest or hanging out with friends and practicing 35mm film photography.’ View her LinkedIn and Twitter