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Bleached coral on Lizard Island, Queensland © WWF-Aus / Alexander Vail
The vibrant colours of corals come from algae that live inside their tissues. It gives corals energy, allowing them to grow and flourish.
When water temperatures are are too hot for too long, corals expel the algae which causes them to turn white.
Though they can recover from bleaching, if bleached corals are exposed to warmer water for eight weeks or more, they become vulnerable to diseases and begin to die.
Coral bleaching is the ghostly face of climate change. Corals are paying the price for our reliance on mining and burning fossil fuels like coal and gas.
As carbon pollution is emitted into Earth’s atmosphere, it traps heat and causes temperatures to rise. The ocean then becomes warmer, resulting in heatwaves that cause stress to corals.
Ocean heatwaves can destroy entire reef ecosystems and the marine life that depend on healthy, thriving corals.
Back-to-back mass bleaching events in 2016 and 2017 wiped out half of the shallow corals on the Great Barrier Reef.
For the first time researchers recorded severe coral bleaching events on coral reefs in every region of the world, with 16% of corals killed around the world. Half the reefs on the Great Barrier Reef were impacted.
The Great Barrier Reef suffers another mass bleaching event.
As coral bleaching became an issue of world concern, universities and research institutes strived to learn more.
The second global mass coral bleaching event hit the world’s reefs. Luckily, the Great Barrier Reef avoided extensive damage.
As ocean temperatures continue to rise, experts declared the third global bleaching event was underway and that it had started in mid-2014.
The largest die-off of corals ever recorded on the Great Barrier Reef, with an area roughly 1,100 km long affected.
By February 2016
The National Oceanic and Atmospheric Administration (NOAA) confirmed we were experiencing the longest global coral bleaching event ever observed.
The Reef suffered mass coral bleaching for a shocking second year in a row. The fragile corals were then hit by devastating winds caused by Tropical Cyclone Debbie and polluted floodwaters.
In just two years, an estimated two-thirds of the Reef’s corals were damaged.
© naturepl.com / Doug Perrine / WWF; © Troy Mayne; © WWF / James Morgan; © Shutterstock / Andrey Nosik / WWF; © Shutterstock / Debra James / WWF
Coral bleaching in Lizard Island © WWF-Aus / Alexander Vail
Large export vessels are loaded with coal at Gladstone Port in Queensland, Australia © WWF / James Morgan
Wind and solar power © Shutterstock / Soonthorn Wongsaita / WWF
A crown of thorns starfish being injected by a worker with a toxin developed at the James Cook University © WWF / James Morgan
This nitrogen filled pollution smothers corals, blocking them from sunlight and fueling algal blooms, which drives outbreaks of the coral-eating crown of thorns starfish.
Beyond addressing global warming, WWF-Australia is dedicated to helping repair land surrounding the Great Barrier Reef, advocating for laws to reduce pollution, working with Queensland farmers to adopt sustainable farming practices and proper fisheries management.
© Darren Jew
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