Australia’s Great Barrier Reef, the largest living structure on Earth, has recently suffered the worst bleaching event of all time. It has impacted over 90% of the reef and killed more than a third of its corals. Some areas of the reef are now totally devastated.
Marine researcher Justin Marshall spent a week surveying the northern region of the reef and found that entire swathes are experiencing “complete ecosystem collapse”, the Guardian reported.
“The lack of fish was the most shocking thing,” Marshall told the Guardian. “In broad terms, I was seeing a lot less than 50 percent of what was there [before the bleaching]. Some species I wasn’t seeing at all.”
The black-and-white striped humbug damselfish and green chromis were once common in and among the reefs, but they have now almost completely disappeared, according to Marshal.
Bleaching off the coast of Australia has been driven by climate change and a powerful El Nino. If the sea warms too rapidly, coral expels the algae living in its tissues, causing it to turn completely white.
It doesn’t necessarily kill the coral, but it subjects them to extra stress, lowering the chance of survival.
According to the Guardian, this is the most widespread coral bleaching event in recorded history.
The Great Barrier Reef is estimated to be 20 million years old, home to more than 1,5000 fish species and composed of more than 2,900 individual reefs.