In Brief
  • The Great Barrier Reef is in the midst of an unprecedented coral bleaching event that has been ongoing for that last four years.
  • Due to ocean warming and other environmental factors, coral bleaching may become the new norm by 2040s if steps aren't taken to curb it.

The Fall of the Great Barrier Reef

You’ve more than likely heard of the Great Barrier Reef: located off the northeastern coast of Australia, it stretches across 2,300 kilometers (1,429 miles) and can even be seen from space. It’s been deemed one of the Seven Wonders of The Natural World, and is the world’s largest contiguous structure to be made by living organisms.

The Great Barrier Reef began forming millions of years ago. Some corals that exist today date back to the early 1700s, meaning they’ve witnessed centuries of history unfold. Unfortunately, these ancient corals are dying at an alarming rate.

The reason is coral bleaching. When corals bleach, they turn white. This is because their “skeleton” is made up of hard limestone. Normally, coral contain symbiotic algae that live near their surface. The algae undergo photosynthesis to provide the coral with the energy it needs to survive. Stress factors such as waste, climate change, and warming waters can easily force the coral to expel their algae — which in turn causes them to literally starve to death over time.

Today, the reef is in the midst of the worst ever coral bleaching event ever recorded — one that’s now entering its fourth consecutive year. Last year, around half of the corals died in the worst-hit areas. To make matters worse, divers are noticing new areas of significant bleaching in the northern portion of the reef.

The Wrath of El Niño

Coral are so sensitive to temperature that even a 1-2 degree Celsius rise in ocean temperature is enough to wipe out entire portions of a reef. The first quarter of 2016 was found to be the hottest ever recorded, and we have our abnormally-warm El Niño to thank. Combined with global climate change, ocean temperatures have been on the rise for the last century.

“The baseline of sea temperature is going up decade by decade by decade due to global warming,” said Terry Hughes, director at the ARC Centre of Excellence for Coral Reef Studies in Townsville, Queensland. “When an El Niño event comes along, it adds an extra spike to that rising baseline. We’ve always had those spikes, but before global warming they didn’t cause the damage that they do now.”

The Great Barrier Reef might be a single living structure in itself, but it’s also an enormous habitat for many other living organisms. It’s home to 1,500 or so types of fish, and countless other species living amongst them. With their natural habitat decimated, it’s not hard to imagine the devastating domino effect.

On average, it takes about ten years for coral to bounce back from the effect of bleaching. But with the overall rising ocean temperatures, it could certainly take far longer than that now. Unless we do something, scientists are afraid that bleaching could become the new norm for coral: it could be happening annually by the 2040s, resulting in the further decline of reefs found around the world. We must take aggressive action towards reversing the damage that we’ve done, or else the former Great Barrier Reef will just become a pretty picture on a postcard of a time once lived.