Why corals matter2019-11-11T15:23:28+01:00

Coral reefs only cover 0.2% of the Ocean floor, yet they host between 20% and 30% of the World’s marine biodiversity.

A 1 square kilometer reef can produce an average of 15 tons of food per year, thus ensuring food security for neighboring communities.

Like other coastal ecosystems, coral reef are key carbon sinks that help mitigate climate change. They also act as a natural barrier against climatic disasters and erosion.

Yet, it is estimated that we have lost between 30% and 40% of our coral reefs in the last three decades. Like oceanographer Dr. Sylvia A. Earle said:

“Half the coral reefs are still in pretty good shape, a jeweled belt around the middle of the planet. There’s still time, but not a lot, to turn things around.”

What are corals?

Corals are made of tiny animals called Polyps, living in symbiosis with an algae, the zooxanthellae, which provides it with nutrients. Thanks to them and their photosynthesis, Corals build their limestone skeleton that form Coral Reefs !

Zooming on a coral :

To know more, check out this article & video to know everything about Corals, by the World Resources Institute !

Corals reefs are the most diverse ecosystems in the world : that’s why they’re often called “The Rainforests of the Ocean” !

More than 25% of the world’s marine biodiversity is hosted by coral reefs,  4,000 different fish species ; and 75% of the Earth’s known species !

Their complex habitat provides shelter and nutrients for a great diversity of species to grow. But just like forests, reefs and their ecosystems also emit oxygen and absorb carbon.

To learn more, you can visit the NOAA Coral Reefs Monitoring website !

Throughout the world, 1 person out of 15 depends on Coral Reefs for their livelihood, food security and local economy. Thanks to their complex habitat, they can produce up to 15 tons of food per year & per square kilometer.

But they also reduce waves’ intensity for coastal villages, and limit erosion ! In many parts of the world, they have medicinal and spiritual importance for communities.

To know more, check out the UN World Ocean Assessment or watch this video by the World Bank showing Coral Nurseries’s impacts on Indonesian communities !

What challenges are they currently facing?

Climate change is threatening coral reefs in many way : the rising temperatures of the waters will cause more and more frequent bleaching events.

The loss of marine biodiversity is also enhancing the population of predator species, that thrive and outnumber coral reefs : the most noticeable example is the Crown of Thorns starfish.

But the increasing of extreme weather events is also damaging a lot of coral reefs throughout the world, especially in Southeast Asia where they’re more and more frequent.

To dive further : an article & infography showing impacts of climate change on reefs ; some key facts from the Great Barrier Marine Park Authority.

Corals emit oxygen and absorb CO2, just like trees, and just like us ! By doing so, they absorb much of the CO2 our human activities produce. About 26% of our carbon emissions are directly absorbed in the oceans every year ; which increases ocean acidification – a global threat to coral reefs.

But Coral Reefs play an important part here as well : they need carbon dioxide to built their limestone skeleton. Coral Reefs are among the most diverse ecosystems on Earth, and they build the most ancient living colonies !

To know more, you can visit this scientific article relayed by The Guardian, or this paper by National Geographic News.  Also Corinne Le Quéré et al., « Global carbon budget 2015 », Earth System Science Data, vol. 7, n° 2 (décembre 2015), 349-396 (371)

We call “bleaching” the consequence of ocean acidification and rising temperatures on corals : they’re under stress, and expel their living algae out of their skeleton.

By doing so, they loose their colors and their food supplier. If nothing is done rapidly after they’ve bleached, they face death.

But hopefully, many solutions exist and coral reefs are naturally highly resilient species ! Therefore they can recover from a bleaching event.

To know more, check out the Australian Great Barrier Reef Marine Park Authority’s presentation ; or to know more about coral bleaching outside of Australia, this Global Bleaching free resources !

How can we help?

6,5 milions tons of waste end up in our oceans every year. 50% of them are plastic that will take hundreds of years to decompose.

By refusing single-use plastic, reducing your waste, recycling, you already have a huge impact on our oceans !

To know more : the World Ocean Network published some key facts about oceans pollution.

To have tips on reducing your plastic consumption, you can check out One Million Women website !

A Coral Nursery is an efficient, quick, and cheap way to rebuild coral reefs, increase their resilience and benefits local communities.

After having collected broken pieces of coral on the seabed, we attach them to an organic substrate that we place at a perfect depth and temperature to enhance their growth in a natural way.

After a few days, biodiversity is already thriving again. After 1 year, the whole reef is totally rebuilt !

To know more : a BBC video & article explaining coral nurseries’ impacts ; or an article showing the construction of a nursery step by step !

By talking about the oceans and corals around you, to your friends and family, or on social media, you’re giving a voice to the voiceless !

Not many people know what corals are, what their importance is, and how we can help them easily. Become a Coral Ambassador to Save Our Reefs !

When traveling, think about your impacts on the environment & coral reefs : don’t litter, use sustainable materials like organic sunscreen & reusable cups.

When swimming or snorkeling, be careful with your fins : you can kill corals just by accidentally hitting them ! And most of all : never walk on Corals !

Check out NOAA’s infography on 10 things we all can do to protect our Reefs while traveling

[Picture by our partner ©Alexis Rosenfeld]