Coral reefs are titans of the marine world
The discovery of a super-sized coral reef off the coast of Australia brings these intricate and beautiful structures back into the news, but what is the state of the world’s reefs?
It all happened on 20th October 2020, off the coast of Cape York, Australia. Scientists from the Schimdt Ocean Institute were aboard their research vessel, the Falkor, when they made a discovery that towered above all others.
The scientists were mapping the sea floor around Australia’s Great Barrier Reef, when they found a detached reef standing as high as 500 metres off the seabed. To put this into perspective, this newly discovered reef is taller than the Empire State Building, the Sydney Tower or the Petronas Towers.
But what exactly are coral reefs, and how is human activity threatening their future?
Coral reefs are complex organic structures
When you look at pictures of coral reefs, you see vibrant, colourful structures which appear to be made of inanimate rock, but that’s not true. Coral reefs are actually teeming with life- each reef is a hardened cluster of tightly packed calcium carbonite shells which serve as homes to creatures call polyps.
They secrete various colours into the calcium carbonate while living, giving coral reefs a dizzyingly colourful display to the human eye. The Great Barrier Reef is the world’s single-largest coral reef system, spanning 348,700 square kilometres.
The discovery by the Schmidt Ocean Institute is significant, as it reveals the extent to which coral reefs can grow. Wendy Schmidt, a co-founder of the Institute, explained its significance, saying:
The state of our knowledge about what’s in the ocean has long been so limited. Thanks to new technologies that work as our eyes, ears and hands in the deep ocean, we have the capacity to explore like never before. New oceanscapes are opening to us, revealing the ecosystems and diverse life forms that share the planet with us
Human activity is bleaching our reefs
While coral reef structures look strong and sturdy, they are incredibly sensitive to the changes in climate. Each time a coral reef dies, it undergoes a process called “bleaching”, in which the polyps perish, draining the reefs of their colour. This leaves behind a mound of bleached-white calcium carbonate on the seafloor, an empty shell of its former self.
Changes to the temperature and acidity of our oceans can be key drivers in the bleaching of coral reefs all over the planet. The Intergovernmental Panel on Climate Change (IPCC) claims that our coral reefs are so vulnerable that if global temperatures rise 1.5 degrees Celsius (relative to pre-industrial levels) by 2100, we could lose 70-90 per cent of the world’s coral.
A rise of two degrees Celsius relative to pre-industrial levels, by contrast risks killing off virtually all the world’s coral. If such a scenario comes to pass, many of the people alive in the world today may live to see the total extinction of these vulnerable organisms.
Scuba-diving is one of the most popular ways for people to see coral reefs up close while on holiday. Read all about our 10 ways to travel greener, to help protect coral reefs during your travels.