World - Decade of climate breakdown saw 14 per cent of coral reefs vanish

Between 2009 and 2018, the continuous rise in sea temperature cost the world 14 per cent of its coral reefs – that’s more than the size of Australia’s reefs combined – a UN-backed report revealed on Tuesday.

In the Sixth Status of Corals of the World: 2020 Report, experts from the Global Coral Reef Monitoring Network, funded by the UN Environment Programme (UNEP), collected data from more than 300 scientists from 73 countries, over a span of 40 years, including two million individual observations.

It revealed that almost invariably, sharp declines in coral cover, correspond with rapid increases in sea surface temperatures, indicating their vulnerability to temperature spikes, and found that this phenomenon is likely to increase as the planet continues to warm.

Invaluable ecosystems

Dynamic underwater coral cities support up to 800 different species of hard coral and are home to more than 25 per cent of all marine life, according to the report.

Soft corals bend and sway amongst the craggy mountains of hard corals providing additional homes for fish, snails and other marine creatures.

And reefs harbour the highest biodiversity of any of the world’s ecosystems, making them one of the most biologically complex and valuable on the planet.

Coral bleaching

However, when waters get too warm, corals released their colourful micro-algae, turning a skeletal white colour. Some glowed, by naturally producing a protective layer of neon pigments, before they bleach.

“Bleaching can be thought of as the ocean’s version of the ‘canary in the coral mine’ since it demonstrates corals’ sensitivity to dangerous and deadly conditions”, the Status of Coral Reefs explained.

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