<span style="color: #222222;">Australia announced plans today to explore concepts such as firing salt into clouds and covering swathes of water with a thin layer of film in a bid to save the embattled Great Barrier Reef. <br />''<br />''The UNESCO World Heritage-listed reef, about the size of Japan or Italy, is reeling from two straight years of bleaching as sea temperatures rise because of climate change.<br />''</span><br />'' <span style="color: #222222;"> Canberra in January offered US$1.5 million to attract innovative ideas to protect the site, which is also under pressure from farming runoff, development and the predatory crown-of-thorns starfish.<br />''<br />''Six schemes selected out of a total of 69 submissions will be tested to see if they are feasible. One selected concept is cloud brightening where salt crystals harvested from seawater are fired into clouds, making them more reflective and therefore deflecting solar rays back into space.<br />''<br />''Another idea was a biodegradable "sun shield", where an ultra-thin film containing light-reflecting particles covers some reef waters to protect corals from heat stress.<br />''</span><br />'' <span style="color: #222222;"> Other short-listed projects include mass producing coral larvae with the aid of 3D-printed surfaces to support new growth, and large-scale harvesting and relocation of larvae.<br />''</span><br />'' <span style="color: #222222;"> Experts have warned that the 2,300-kilometre long area could have suffered irreparable damage.<br />''</span><br />'' <span style="color: #222222;"> While the government has pledged to tackle climate change,which is the greatest threat to the world's largest living structure,there has also been a push to explore shorter-term measures to buy the reef some time.</span><br />'' <span style="color: #222222;"> </span><br />'' <br />