St Mary's Cathedral is illuminated as part of a Christmas lights display in celebration of Christmas on December 19, 2014 in Sydney, Australia. (Photo by Brendon Thorne/Getty Images)

A man takes pictures at the finish line during the Colour Run at Centennial Park in Sydney August 25, 2013. According to organizers, 15,000 runners registered to complete the 5km (3 miles) course in Centennial Park on Sunday, being covered in blue, pink, orange and yellow powder on their way to the finish line. (Photo by Daniel Munoz/Reuters)

The Sydney Skyline is seen before the lights are switched off for Earth Hour on March 26, 2011 in Sydney, Australia. Earth Hour encourages individuals around the world to turn off their lights for one hour at 20:30 local time on March 26, 2011 to take a stand against climate change. The largest Earth Hour was in 2010 when 128 countries participated.

A Sydney Aquarium diver uses a vacuum to clean the gravel in the Great Barrier Reef tank as a Ray Shark swims by September 26, 2006 in Sydney, Australia. The Aquarium is undergoing its annual spring clean to prepare for the school holidays using vacuums, along with sea creatures like Sea Cucumbers, Sea Urchins, Cleaner Wrasse Fish and Sea Stars to help complete the job. (Photo by Ian Waldie/Getty Images)

Australian jouster Kimberly Belcher poses for a portrait in her armour on the sidelines of the jousting tournament at the St Ives Medieval Fair in Sydney, one of the largest of its kind in Australia, September 22, 2016. (Photo by Jason Reed/Reuters)

Sydney artist Phillip George poses with two surfboards of his own design at Marks Park, Tamarama on December 16, 2008 in Sydney, Australia. (Photo by Don Arnold/Getty Images)

La Traviata chandelier is positioned on stage at Mrs Macquarie's Point on March 16, 2012 in Sydney, Australia. Covered with 10,000 Swarovski crystals, the 9 metre high chandelier will be hung above the performing stage of the La Traviata Opera. (Photo by Brendon Thorne/Getty Images)

A swimmer stops short of a red algae bloom at Sydney's Clovelly Beach on November 27, 2012, which closed some beaches for swimming including Bondi Beach for a period of time. While the red algae, known as Noctiluca scintillans or sea sparkle, has no toxic effects, people are still advised to avoid swimming in areas with discoloured water because the algae, which can be high in ammonia, can cause skin irritation. (Photo by William West/AFP Photo)