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Did You Know 50% of the Great Barrier Reef Is Dead?

Estimated reading time: 8 minutes


Did You Know 50% of the Great Barrier Reef Is Dead?

By Joe Greenwell

What if I told you the world’s largest living organism is dying? 

That would alarm you, right? 

Brace yourself. The Great Barrier Reef is the world’s largest living organism. 

And it is dying.

At an alarming rate. 

The Reef spans 1,429 miles and covers more than 133,000 square miles. For perspective, Oregon is 98,379 square miles. 

You can see the Reef from space stretching along the northeastern coast of Queensland.

It consists of nearly 3,000 individual coral reefs and more than 400 types of hard and soft corals. 

The corals are the foundation of a massive ecosystem. They house an immensity of marine plant and animal life. From the tiny algae living in the corals’ tissue to the reef sharks patrolling the perimeters. 

This UNESCO World Heritage Site is at risk of disappearing by the end of the century. 

And it’s not only the Great Barrier Reef at risk. It’s most of the corals in the world ocean. 

And it’s not only the corals. It’s all the plants and animals that depend on them. Coral reefs are the most biodiverse ecosystem on earth. More biodiverse than the rainforest.

The NOAA estimates that over 25% of all marine animals depend on coral reefs in some way during their life cycle. The impact of such a loss will reverberate well beyond the corals themselves. 

Size and diversity of the reefs don’t protect them. Between 1995 and 2017, 50% of the corals on the Great Barrier Reef died. 

According to Professor Terry Hughes of the ARC Centre of Excellence for Coral Reef Studies, the 50% decline is widespread. It includes small, medium, and large corals in shallow and deep water. 

These animals — yes, they’re animals — have been around for millions of years. So why are they dying off so fast now? Before I dive into the challenges corals are facing, let’s answer a basic question:

What Is a Coral?

I said above that corals are animals. Which is true. But it’s complicated.

See, what we think of as a coral is actually a colony of polyps. Polyps are little sac-like creatures with a mouth and tentacles. Kind of like upside down jellyfish.

These little polyps join together with other identical polyps — sometimes millions of them. As they grow, they secrete calcium carbonate under and around themselves for protection. 

Calcium carbonate is the white, chalk-like skeleton you see in many shapes on the ocean floor. 
The polyps cover the skeleton in a translucent skin-like tissue. 

Here’s where it gets complicated. And colorful. 

Over millions of years, these polyps befriended a microscopic algae called Zooxanthellae (Zow-uh-zan-thel-ee). These miniscule plant cells live in the polyp’s tissue. They give the corals their stunning colors. 

But they don’t only make the coral beautiful. They feed it.

In fact, corals get most of their nutrition from these algae by photosynthesis. This works out well. The algae photosynthesize during the day. The polyps capture food with their tentacles at night. 

The polyps protect the algae and the algae feed the polyps. Both parties benefit. With such an efficient system, why are these wonderful creatures dying faster than ever? Let’s talk. 

Why Are Coral Reefs Dying?


Coral reefs are dying because of rising ocean temperatures. Temperatures are increasing faster than ever because of global warming.

And who is to blame for global warming? If you’re human, please raise your hand.
The millions of tons of carbon dioxide we’re emitting every year has a devastating effect. It’s called the greenhouse effect.

When we burn fossil fuels, they emit carbon dioxide (CO2). CO2 is a heat-trapping gas. It hangs in the atmosphere and holds the sun’s energy in — like a greenhouse.
The energy trapped by the insulating gases raises the earth’s temperature. But it raises the ocean’s temperature much more.

According to the IPCC’s Fifth Assessment Report, the ocean absorbs more than 93% of this excess energy.

Imagine if we didn’t have the ocean to absorb all that heat. 

Scientists already have.

They estimate that temperatures on land would have risen 36°C or 96.8°F, without the ocean to protect us. We owe the ocean some gratitude for taking the heat. Literally. 

Imagine trying to drink your pumpkin spice latte wearing your favorite sweater on a 130°F autumn day. We have the ocean to thank for those cool autumn days.

How Do Warmer Ocean Temperatures Kill Coral?


Like most creatures, coral polyps and algae thrive in certain temperatures. Outside of those temperatures, they experience stress.

Here’s how it happens. When temperatures rise, the warmth stresses the polyps and the algae. In an attempt to regain homeostasis, the polyps expel the colorful algae. Without the algae, the corals look bleached white.

Think of the coral’s response like a fever. When we have an infection, our bodies fight it to regain homeostasis. We experience fever, exhaustion, cold sweats, runny nose, and more. Coral polyps expel their aglae for a similar reason. 

The polyps can survive without the algae for a short time. But they are vulnerable to disease, starvation, and pollution without their plant partners. If coral polyps don’t begin accepting the plant cells again, they die.

When corals die, another type of algae coats the skeleton giving it a fuzzy grimy look. Over time, the coral skeleton crumbles.

As the ocean continues to warm, coral bleaching events become more frequent.

The first recorded events happened in the early 1980s. Then again in 1997 to 1998. Then 2010. Then back-to-back in 2016 and 2017. 

According to Professor Hughes, the Great Barrier Reef has suffered “five mass bleaching events – 1998, 2002, 2016, 2017 and 2020.”

With more frequent bleaching events, the corals have less time to recuperate. Thus more corals die each year.

This is why UNESCO predicts, “The coral reefs in all 29 reef-containing World Heritage sites [will] cease to exist by the end of this century.” That is, if we continue burning fossil fuels and emitting greenhouse gases.

What Are We Doing to Save the Corals?

Scientists are looking for creative ways to save the corals.

Methods like coral in vitro fertilization (IVF) and microfragmentation strive to save at-risk species of corals. 

Some scientists are using assisted evolution to help corals cope with warmer temperatures. 

These inventive methods help some corals survive, but the real problem continues.

●      Burning fossil fuels
●      Greenhouse gas emissions
●      Global warming
●      Rising ocean temperatures.

To solve the real problem, we need global participation.  

In 2015, the United Nations Climate Change Conference negotiated the Paris Agreement. It set a goal of keeping the global average temperature below 2°C or 3.6 °F.

Stopping and reducing the rising global temperature is critical to saving coral reefs. If nations around the world commit to this goal, everyone will benefit — including the corals.

It’s in everyone’s best interest. But we all must work together.

Under the Trump administration, the United States withdrew from the Paris Agreement, November 4, 2020. President Trump argued the agreement was unfair to the U.S. economy. 

According to an EPA study, the U.S. produces 15% of the world’s CO2 emissions. As the second largest contributor, the U.S. needs to be a leader in this most-important issue. (The U.S. will likely rejoin the Paris Agreement under President-elect Biden.)

Because saving corals isn’t only an environmental issue.

Why Are Coral Reefs Important to People?


For tiny animals most of us never see, corals sure are important to our welfare.

First, let’s look at the Great Barrier Reef.

The Reef brings Australia’s economy $6 billion every year and provides 69,0000 jobs. It also supports marine life and a thriving fishing industry.

As the name suggests, the Great Barrier Reef acts as a breakwater. It prevents damaging waves from destroying coastal infrastructure. 

But if you don’t care about Australia, you should still care about the Great Barrier Reef.

Here’s why.

The Great Barrier Reef is representative of reef systems around the world. And they’re all suffering. 

Look at the reefs in the Florida Keys. 98% of its original coral cover is lost. 

Even with such great losses, the remaining Florida corals still benefit the state. They’re worth $8 billion to Florida’s economy, and they provide over 70,000 local jobs.

But coral reefs don’t just benefit the economy. They’re underwater pharmacopeias — important for medical research. 

If you know anyone with “cardiovascular diseases, ulcers, leukemia, lymphoma and skin cancer,” you have coral reefs to thank for their treatments. 

From a global perspective, more than 500 million people depend on coral reefs. For those people, corals are the foundation of an ecosystem that
●      Nourishes their bodies
●      Fills their fishing nets
●      Powers their trade
●      Fuels their tourism
●      Defends their shores

Protecting corals is a human issue.

What Can You Do to Save the Corals?

Educate yourself and then act.

If you’re lucky enough to live near corals, learn about local threats. Avoid touching corals when diving or anchoring on them when boating.

Wear environmentally friendly sunscreen. Chemicals in sunscreen kill coral. Especially when they’re bleaching and vulnerable. Two of the main chemical culprits are oxybenzone and octinoxate. So look for sunscreens marked “reef safe.”  

Also, join a local ocean or river cleanup. If there isn’t a cleanup near you, learn more about how Ocean Blue Project (OBP) supports your efforts.  

No matter where you live, here are three easy ways to help save the corals.

1. Educate yourself — The Ocean Blue Project blog has tons of fascinating articles. You can learn about creative recycling, proper garbage disposal, and the impact of plastic waste on our ocean. I recommend reading about how you can help stop the massive plastic waste problem for starters.

2. Donate to OBP — For every dollar you give, OBP takes one pound of microplastics out of the ocean. These tiny plastic particles cause disease in corals. If the water temperatures are rising than coral fragmenting is not the answer.

3. Spend consciously — Feeling guilty about your Amazon purchases? I have a solution for you. Make OBP your AmazonSmile Charitable Organization. That way, a portion of every purchase goes to saving the ocean and its corals. No more guilt! All you have to do is adjust your AmazonSmile account to Ocean Blue Project. It’s easy. Click here for three simple steps and start saving corals immediately.

Author Bio: Joe Greenwell is a copywriter living in Northeast Ohio. He’s passionate about great literature, and he loves learning. You can spot him with his wife hiking in the Cuyahoga Valley National Park or on the street pretending to enjoy running. You can connect with him on LinkedIn.