Melbourne

In just a few years, 8 million native angasi oyster hatchlings have been placed in the waters off Victoria, South Australia, Queensland and Western Australia, on the recycled mollusc shells collected from restaurants. They've turned empty, sandy seabeds into thriving ecosystems.

More than 13,000 stings were recorded in Queensland alone last week, with more than 2,500 people seeking treatment over the weekend, according to rescue organizations.

Victoria's biggest-ever reef restoration project is underway, in attempt to restore the once abundant populations of native oysters in Port Philip Bay.