By Julia Petzl-Berney, UNE Discovery

South Australians are being encouraged to eat local oysters and donate the shells so that they can be recycled and used to recreate shellfish reefs, as reported by various media outlets. These reefs used to occur naturally off the South Australian coastline, but were gradually destroyed by land and water management practices after colonialisation.

After sterilisation, the shells will be placed in a biodegradable cage and lowered in the water for the microscopic baby oysters, known as spats, to settle on. To make the location more attractive, researchers have discovered that using underwater speakers to play the sounds of a healthy reef attracts more spats. This shows the importance of using science and collecting data to help design the most effective methods for projects such as this.

Marine ecologists hope that the water filtering behaviour of shellfish, including local oysters, just one of which can filter 100L of water per day, will improve the water quality in time, potentially making it more resilient to future algal blooms.

Sources & more reading:

https://www.theguardian.com/environment/2025/dec/01/south-australia-oyster-shell-donation-reef-restoration

https://www.theguardian.com/the-nature-conservancy-reef-restoration/2025/dec/03/could-oyster-reefs-help-to-restore-australias-coastal-ecosystems

https://www.abc.net.au/listen/programs/adelaide-breakfast/flinders-restructure/105805810