The marine environment of Adelaide’s south will get a significant boost, with O’Sullivan Beach confirmed as the location for SA’s second metropolitan shellfish reef.

Construction of the five-hectare native shellfish reef will be about 500 metres off O’Sullivan Beach, and is expected to begin in late 2021.

The Onkaparinga shellfish reef restoration project is a partnership between the federal and state governments, The Nature Conservancy Australia and the City of Onkaparinga.

Federal Minister for Environment Sussan Ley says the new shellfish reef will boost local tourism, grow fish stocks and improve water quality.

“The new shellfish reef off the coast of O’Sullivan Beach will be more than twice the size of Adelaide Oval and will be constructed using a limestone reef base, with hatchery-raised Australian Flat Oysters to create a flourishing marine environment,” she says.

“Shellfish reefs provide significant environmental benefits including creating habitat for fish and improved water quality, but they can also provide new recreational and economic opportunities.

“The Morrison Government is investing $20 million in restoring native reefs around the country and is proud to partner in this project which builds on the recent completion of the Windara shellfish reef, near Ardrossan and the newly established Glenelg metro shellfish reef.”

Shellfish reefs are part of South Australia’s natural heritage and were once common along the coastline, however, from the late 1800s to mid-1900s the reefs suffered from the impact of overfishing, dredging, water pollution and disease.

State Minister for Environment and Water David Speirs says O’Sullivan Beach was chosen as the next metro shellfish reef as it offers suitable environmental conditions with good opportunities for colonisation of marine species from the nearby rocky reefs.

“We have already seen the success of other shellfish reefs across the state and this new one at O’Sullivan Beach will benefit the natural environment and provide an economic boost through increased tourism opportunities such as snorkelling, diving and fishing,” he says.

“It’s vicinity to the existing O’Sullivan Beach boat ramp and close proximity to the shore will make it a lot easier for recreational access.

The reef is one of 13 sites identified for reef restoration under Reef Builder, a partnership between the Australian Government and The Nature Conservancy Australia.

The Nature Conservancy’s Acting Oceans Director Dr Fiona Valesini says shellfish reefs provide homes for many marine species and boost fish stocks.

“Oysters are also like the kidneys of our oceans, with each one filtering 100 litres of water a day. This helps improve local water conditions which supports the return of other ecosystems like seagrass.”

City of Onkaparinga Mayor Erin Thompson says the O'Sullivan Beach reef is a big win for the community.

“Our community’s unwavering support for a shellfish reef in Onkaparinga played a key role in bringing it to O’Sullivan Beach, and it will be a fantastic addition to Onkaparinga’s iconic 31-kilometre coastline.”

The project is part of The Nature Conservancy’s larger national shellfish restoration program that aims to rebuild 60 shellfish ecosystems across Australia. 

If achieved, Australia will be the first nation in the world to have recovered a critically endangered marine ecosystem.

Image by Arhnue Tan from Pixabay