Why is the Great Barrier Reef in danger?

World Today

Photo by Greg Torda from the ARC Center of Excellence Coral Reef Studies.

Australia’s Great Barrier Reef is home to thousands of different species of marine life, and one of the seven natural wonders of the world.

And it’s dying.

Why is the Great Barrier Reef in danger?

Australia’s Great Barrier Reef is home to thousands of different species of marine life, and one of the seven natural wonders of the world. And it’s dying. The coral reef runs along the northeast coast of Australia for 2,300 kilometers (1,429 miles). Coral – and the algae that live in their tissues – need each other to survive. Algae generate nutrients for the coral, allowing the reef to grow. With the protection and minerals provided by coral, the algae undergo photosynthesis, which creates oxygen. Warming ocean temperatures – caused by climate change – breaks down this relationship.

The coral reef runs along the northeast coast of Australia for 2,300 kilometers (1,429 miles).

Coral – and the algae that live in their tissues – need each other to survive.

Algae generate nutrients for the coral, allowing the reef to grow. With the protection and minerals provided by coral, the algae undergo photosynthesis, which creates oxygen.

Warming ocean temperatures – caused by climate change – breaks down this relationship.

In warmer water coral expels the algae, leading to “coral bleaching”.

Coral turns white without algae.

Bleached coral can recover if the ocean cools and algae recolonize, but it can take at least a decade for that to happen.

If the algae don’t come back, the coral dies.

In 2017, scientists recorded severe coral bleaching—especially in the central part of the Great Barrier Reef.

It was the second bleaching event in a year.

The last one occurred in March 2016, and it was the worst ever recorded. Bleaching affected 93 percent of the reef.

Scientists said the bleaching killed more than a third of the northern and central part of the reef.

Before that, there were only two other recorded mass bleaching events—one is 1998 and the other in 2002.

When mass-bleaching events happen close together, such as the ones in 2016 and 2017, one scientist said there is “zero prospect of recovery” for coral severely bleached in 2016.

Scientists warn that immediate global action is needed to secure the future of coral reefs.

But the world seems to have a hard time understanding how serious this is.

A global poll by Pew Research asked respondents if they thought climate change was a “very serious problem.” The results were as follows:

The Great Barrier Reef is the largest in the world, but coral reefs live in more than 100 countries across the globe.

And are the home to 25 percent of the planet’s marine life.