The health of the Great Barrier Reef, one of Australia's most extraordinary natural wonders and top tourist attractions, has been much debated in recent years.
Global warming, resulting in warmer and more acidic seas, as well as pollution from agricultural land and coral predators like the "crown of thorns" starfish are among the risk factors cited for the reef and the wildlife that depends on it.
In 2011, prominent reef scientist Ove Hoegh-Guldberg from Queensland University's Centre for Marine Studies, said the whole reef could die unless carbon emissions started declining sharply.
Higher ocean temperatures could result in widespread coral "bleaching," increasing the risk that the coral will die. Half the coral cover of the reef had died since 1960, he and others said at a conference in 2012.
A study by Queensland state government last year found the reef had lost half its coral cover over the past 30 years. Almost all of the most pristine parts of the reef are experiencing severe bleaching, according to a National Coral Bleaching Taskforce study in March.
Other academics including James Cook University's Sean Connolly have said that the coral reef - listed as a World Heritage site in 1981 - is hardier and more able to adapt to changing sea conditions than many fear.
The composition of the reef - made up of over 2,500 individual reef systems - may change as some species adapt better than others, but the reef as a whole will survive, they argue.
In June last year, the United Nations Educational, Scientific and Cultural Organization (UNESCO), decided not to place the reef on its endangered list, but only on condition that Canberra submit a report by December 2016 detailing further efforts to protect the famous reef.