The scene is set for Victoria’s only native oysters to start their work of cleaning the waters in Port Phillip Bay and attracting more fish after 360 tonnes of limestone rubble was laid on the seabed.

Led by The Nature Conservancy, the Port Phillip Shellfish Reef restoration project is one of the state’s largest bay restoration programs.

The limestone, laid off Hobsons Bay near St Kilda, and off Corio Bay near Avalon, will be followed by dropping 300,000 oysters on the rubble over a 600 square metre area.

Once settled on the limestone, the native Angasi oysters will grow into shellfish reefs and help both “people and nature” by cleaning the water and boosting fish numbers.

The Conservancy’s marine restoration scientist, Boze Hancock, said oysters were nature’s water filters.

“Many are filtering at a rate of up to four to five litres an hour,” Dr Hancock said.

“That’s enough to fill a bathtub a day.”

Project manager Simon Branigan said the effect of the $250,000 project would be visible in three years.

A 20-metre barge loaded with limestone rubble to be planted on the sea bed as part of Victoria’s largest reef restoration project in Hobsons Bay and Corio Bay. 

The organisation has now applied to the Victorian government to increase its two restoration sites by 20 hectares.