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https://theconversation.com/the-worlds-coral-reefs-are-bigger-than-we-thought-but-it-took-satellites-snorkels-and-machine-learning-to-see-them-223322>
"The world’s coral reefs are close to 25% larger than we thought. By using
satellite images, machine learning and on-ground knowledge from a global
network of people living and working on coral reefs, we found an extra 64,000
square kilometres of coral reefs – an area the size of Ireland.
That brings the total size of the planet’s shallow reefs (meaning 0-20 metres
deep) to 348,000 square kilometres – the size of Germany. This figure
represents whole coral reef ecosystems, ranging from sandy-bottomed lagoons
with a little coral, to coral rubble flats, to living walls of coral.
Within this 348,000 km² of coral is 80,000 km² where there’s a hard bottom –
rocks rather than sand. These areas are likely to be home to significant
amounts of coral – the places snorkellers and scuba divers most like to visit.
You might wonder why we’re finding this out now. Didn’t we already know where
the world’s reefs are?
Previously, we’ve had to pull data from many different sources, which made it
harder to pin down the extent of coral reefs with certainty. But now we have
high resolution satellite data covering the entire world – and are able to see
reefs as deep as 30 metres down.
We coupled this with direct observations and records of coral reefs from over
400 individuals and organisations in countries with coral reefs from all
regions, such as the Maldives, Cuba and Australia.
To produce the maps, we used machine learning techniques to chew through 100
trillion pixels from the Sentinel-2 and Planet Dove CubeSat satellites to make
accurate predictions about where coral is – and is not. The team worked with
almost 500 researchers and collaborators to make the maps.
The result: the world’s first comprehensive map of coral reefs extent, and
their composition, produced through the Allen Coral Atlas.
The maps are already proving their worth. Reef management agencies around the
world are using them to plan and assess conservation work and threats to
reefs."
Cheers,
*** Xanni ***
--
mailto:xanni@xanadu.net Andrew Pam
http://xanadu.com.au/ Chief Scientist, Xanadu
https://glasswings.com.au/ Partner, Glass Wings
https://sericyb.com.au/ Manager, Serious Cybernetics
