New report notes further decline in Great Barrier Reef coral cover

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TRANSCRIPT:
Coral loss is the reality experienced by the world’s most extensive coral reef ecosystem known as the Great Barrier Reef.
Dr Manuel Gonzalez Rivero is the acting Research Program Director for the Australian Institute of Marine Science. 
He says further bleaching has been seen, primarily caused by climate change-driven heat stress – and not helped by last summer’s tropical cyclones Kirrilly and Jasper. 
“The Great Barrier Reef also experienced the effect of two cyclones. Particularly tropical cyclone Jasper caused the significant damage for two different reasons. One is that cyclones generate wave heights that are above four metres where we’ve seen significant mechanical damage from those wave generators. But also the flooding, the fresh water flooding that comes out of the rains generated by the cyclone also costing significant mortality.”
 
The Institute has unveiled new data that confirms the extent of the damage.
Initial surveys in north Queensland suggest that coral cover has declined on 12 out of 19 reefs between Lizard Island and Cardwell.
More than a third of coral cover was lost across the Cooktown-Lizard Island sector, the largest annual decline for this sector in 39-years of monitoring.
In the Cairns sector, coral cover declined by just over a third across the five reefs – while in the Innisfail sector, it remained similar across its four reefs surveyed.
Dr Rivero says that for Lizard Island and other reefs, coral cover is known as a measure of reef health.
“It’s not the only variable that represents the health of the reef but as overall it indicates the amount of cover or the amount of reef that is covered by corals. Corals are one of the main engineers of reef. Without corals, coral reefs wouldn’t exist. So therefore, the more coral cover we see in the reef typically signals that it’s better.”
Dr Maya Srinivasan is a James Cook University research scientist and says the loss of coral cover can also impact other life.
“Many coral reef fish are highly reliant on live coral particularly branching coral for shelter. Some species feed on live coral and so when you get a loss in coral cover, you get a loss in fish numbers as well, and probably other types of organisms that we’re just not counting them.”
A full assessment of the impact on coral cover across the reefs will be available next year.
But in the wake of these latest findings, there are renewed calls for better action on climate change from the government to help secure the future of the reef.
Scott Heron is the UNESCO chair on climate vulnerability and heritage.
“It’s really important to remember that our Great Barrier Reef is not just a natural wonder, it’s also a source of livelihood for tens of thousands of people. The first thing that we have to do, and we have to do very effectively is respond to the causes of climate change, and that means reducing greenhouse gas emissions.”