Shellfish reefs were once abundant across South Australia, covering more than a third of our coastline.

They teemed with oysters, mussels, crabs, cuttlefish, prawns and fish; supported a significant oyster fishery; and were important to the diets of Aboriginal people.

Since European settlement, shellfish reefs have gradually disappeared. Dredging, overfishing and degradation caused by urban development has made these reefs some of the most endangered marine habitats on Earth.

Enter The Nature Conservancy (TNC). They’re on a mission to rebuild shellfish reefs across southern Australia.

It has partnered with the Department for Environment and Water to build one in Adelaide, and Port Noarlunga and O’Sullivan Beach are two of the three sites vying for a new Adelaide Oval-sized reef.

The organisations now want to hear your feedback on where it should be built.

You can have your say by registering for TNC’s free Christies Beach public forum on Thursday 20 February (See )or by providing feedback via YourSAy at

TNC Marine Restoration Coordinator (SA), Anita Nedosyko, says shellfish reefs are important ecosystems because they provide cleaner oceans, more fish, safer coastlines and jobs for coastal communities.

“Shellfish reefs once thrived along our southern coastline from Noosa to Perth, but overfishing, dredging, pollution and disease wiped out more than 90 per cent by the turn of this century,” Anita says.

“TNC Australia hopes to bring back our lost shellfish reefs by leading the effort to rebuild and protect 60 reefs in six years.

“Projects in Melbourne’s Port Phillip Bay, South Australia’s Gulf St Vincent and Western Australia’s Oyster Harbour are in advanced stages of reconstruction, with others getting underway in and near Perth and Queensland.”

City of Onkaparinga Mayor Erin Thompson says the shellfish reef is a great opportunity for the south.

“This reef would be a perfect addition to the 31 kilometres of coastline in our city,” she says.

“Not only would it help remove water pollution, benefit marine life and help with coastal erosion, the reef would increase recreational activities such as fishing and diving, as well as bringing fantastic opportunities for education and job creation.

“I encourage everyone in Onkaparinga to get behind this by providing feedback on the exciting proposal.”

Each year, every hectare of rebuilt reef:

creates 375kg of new fish stocks including high-value snapper, flathead and whiting

filters 2.7 billion litres of seawater

removes 225kg of nutrient pollution (nitrogen and phosphorus) in coastal areas

reduces coastal erosion by acting as natural breakwaters and rebuilding coastlines

Benefits to people and communities:

direct jobs will be created in traditional trades, maritime construction, science, fisheries and service sectors

more fish and life in our oceans, cleaner water, safer coastline

oyster shell waste is diverted from landfill, to be recycled into new reef

new community volunteering and education opportunities

More info: