It's the world's largest collection of coral reefs, spanning more than 1,430 miles down Australia's eastern coastline. But scientists warn that the Great Barrier Reef is inching closer to an irreversible 'tipping point' as it gets 'repeatedly hammered' by global warming. 

Parts of the Reef have suffered the highest coral death on record, according to experts at the Australian Institute of Marine Science's (AIMS). The marine research centre – which began monitoring the world-famous reef in 1985 – surveyed 19 reefs along the famous region between August and October this year. 

Over the period, 12 out of 19 suffered from a decline in 'coral cover' – the area on a reef that's covered by live coral. One reef suffered from 72 per cent coral mortality, largely due to to high temperatures caused by climate change. What's more, this latest round of underwater surveys only looked at three of the Great Barrier Reef's 11 sections or 'sectors' - so the overall picture may be even worse. 

One of the major contributors to coral loss has been heat stress driven by climate change, said AIMS leader Dr Mike Emslie. If heat continues to affect the area, the algae won't return and the coral is left to die. Heavy rainfall can reduce salinity which corals need to survive, while large storm waves can result in heavy physical damage to coral reefs. 

AIMS expects to survey another five to 10 reefs in the Cairns sector and four to five reefs in the Innisfail sector in the coming months. 

Additional reefs may be surveyed in the Cooktown-Lizard Island sector later in the season, depending on weather conditions. Coral can survive bleaching if it receives nutrients soon enough, but if not, it can cause death within days, previous studies have shown.

Source: The daily Mail

Image: The Daily Mail