• 3 hours ago
Fast-warming seas, overfishing and ocean pollution put coral reefs on course for extinction within a few generations, a landmark UN report said Tuesday. VIDEOGRAPHIC
Transcript
00:00Australia's Great Barrier Reef is the world's biggest coral ecosystem. Visible from space,
00:13it spans nearly 350,000 square kilometres and contains 400 types of coral, 1,500 species
00:20of fish and 4,000 types of molluscs. The World Heritage listed site is a life-sustaining
00:26ecosystem providing food and shelter to species such as the dugong known as the sea cow and
00:31the large green turtle both of which are threatened with extinction. But global warming is wreaking
00:36havoc on the Great Barrier Reef, threatening its very survival. It has suffered badly after
00:41three very serious episodes of coral bleaching in 2016, 2017 and 2020, affecting 98% of the
00:48ecosystem since 1998, according to a recent study. Bleaching occurs when the rise in water
00:54temperatures causes the disappearance of algae which live in symbiosis with the coral, giving
00:59it its colour and nutrients. If they fail to regain their symbiotic plankton friends, the coral die.
01:04Experts say coral reefs no longer have the time necessary for their regeneration between two heat
01:10waves. Aside from climate change, other threats to the reef include cyclones, farming runoff,
01:16coastal development and the coral-eating crown-of-thorns starfish. As well as providing
01:23a home to hundreds of marine species, the Great Barrier Reef supports a multi-billion dollar
01:27tourist industry and tens of thousands of jobs. The scientific community believes a drastic
01:33reduction in greenhouse gas emissions by all countries is vital for the future of corals.

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